Prospective Assessment of Pain and Comfort in Chronic Pain Patients Undergoing Interventional Pain Management Procedures

Prospective Assessment of Pain and Comfort in Chronic Pain Patients Undergoing Interventional... Abstract Objective Interventional pain management procedures have an important role in the management of chronic pain. The present study seeks to identify the proportion of patients who experience severe pain during pain procedures either with or without sedation. There is then an attempt to identify any association of high pain levels with factors such as age, gender, ethnicity, preprocedure pain level, procedure type, tobacco use, and baseline pharmaceuticals taken for both pain and/or mood disorder management. Methods This is a prospective survey study evaluating patients’ discomfort during interventional pain procedures in an outpatient academic facility. Patient discomfort was assessed by the PROcedural Sedation Assessment Survey (PROSAS) and modified for nonsedation cases. Results There were 155 patients in the survey, with 20 of these receiving nonspinal injections. Of the remaining 135 patients who underwent spinal injections, only 10 received conscious sedation. On average, 14.2% experienced severe pain during spinal injections, whereas 20% experienced severe pain with nonspinal injections. Though few patients received conscious sedation, most of these (60%) experienced high levels of pain. There was no correlation between level of procedural pain with age, gender, ethnicity, preprocedure pain level, procedure type, tobacco use, or medication type used. Conclusions The majority of patients who undergo nonsedated interventional pain management procedures do not experience severe pain. There is a small but appreciable group of subjects who seem to experience severe pain that cannot be correlated to any particular clinical characteristic in a standard patient evaluation. Even with standard conscious sedation, there is no clear best method to ensure patient comfort for this high–pain level group. Interventional Pain Management Procedures, Pain, Procedural Discomfort Introduction Interventional pain management procedures (IPMP) have become an integral component in the comprehensive approach for the management of intractable chronic pain. IPMP are conducted in a variety of clinical settings, which include physicians’ offices, hospital procedural suites, ambulatory surgery centers, and operating rooms. There are pain practitioners of both anesthesia and nonanesthesia currently performing interventional techniques. There is, however, little insight as to how comfortable chronic pain patients are during these procedures. Furthermore, there is no approach put forth to identify patients prior to IPMP who may be at risk for increased levels of pain. The injection of local anesthetic, lidocaine, is anecdotally regarded as the most painful aspect of IPMP. The response to local anesthetic injection has been suggested at least in one study to predict pain sensitivity [1]. Indeed, higher pain scores after subcutaneous lidocaine injection correlate with increased anxiety and body movement during needle placement [1]. High levels of pain during lidocaine infiltration have a weak correlation to negative short-term outcomes with lumbar epidural steroid injections to treat painful lumbosacral radiculopathy [2]. Practically, the determination of pain levels after the injection of local anesthetic does not help the clinician plan ahead so as to ensure patient comfort. In general, the use of deep sedation to mitigate patient discomfort especially in an indiscriminate fashion has been discouraged [3]. The loss of the ability of a patient to report increased pain and paresthesias, especially during cervical IPMP, may predispose to significant neurological injury [4]. Not surprising, intravenous (IV) sedation use varies widely across the United States, with a mean of 64% across all IPMP [5]. Previous studies identified anxiety as a key factor driving oral sedation requests in 28% to 58% of patients undergoing spinal injections and recommended against the routine use of sedation [6,7]. While anxiety reduces pain tolerance, direct assessment of pain was not performed in either study. Recognizing the observational fact that some patients can experience severe pain during IPMP despite local anesthetic infiltration, there is a need to explore factors that might help to identify these individuals. The primary aim of the present study was to prospectively determine procedure-related discomfort as rated by both the patient and physician proceduralist. A subgroup analysis in patients who experience high levels of pain was then performed to determine if any correlation exists with known clinical characteristics. Methods Study Design and Patient Selection This is a prospective survey evaluation of pain during IPMP in a tertiary care center outpatient procedural facility. The proceduralist and the patient filled out survey forms for determining procedure-related pain in the absence of sedation. In cases of conscious sedation, an additional form was completed by the nurse administering the sedatives midazolam and fentanyl. The exclusion criterion for the study was insufficient understanding of the English language to complete the survey form. Data Collection All patients enrolled in the survey had the following baseline demographic data including age, gender, ethnicity, preprocedure pain level, procedure type, and tobacco use. In addition, the relevant medications that include antidepressants, membrane-stabilizing agents, benzodiazepines, skeletal muscle relaxants, and morphine equivalent dose of opioids consumed (three months of opioid use or greater) were recorded. The survey form used was the PROcedural Sedation Assessment Survey (PROSAS) (Appendix) [8]. The PROSAS is a clinically relevant, patient-centered questionnaire that specifically addresses periprocedural discomfort. Specifically, The PROSAS includes pre-intra- and postprocedure questions of pain severity completed by patients. This questionnaire also inquires on the adequacy of sedation. The PROSAS also includes intraprocedural pain assessment from both the physician performing the procedure and the nurse administering the sedation. PROSAS rates patient comfort on a 0 (no pain) to 10 (severe pain) scale and satisfaction with sedation level on –5 (markedly less sedation then wanted) to +5 (markedly more sedation then wanted) scale. Physicians, procedural and recovery area nurses were also asked to complete a brief survey addressing the quality of sedation and assessment of patient discomfort. Procedural nurses reported sedation events, which were defined as any case with one or more of the following: 1) any episodes of oxygen desaturation of less than 90% or leading to intervention, 2) any problematic changes in heart rate or blood pressure during intervention (systolic blood pressure < 90 or >160; heart rate <50 or >120), 3) any hemodynamic or respiratory conditions that interrupted the procedure, 4) use of opioids or benzodiazepine reversal agents, 5) hospitalization because of an adverse event of sedation. All sedation-related adverse events were recorded at the time of the procedure. In addition, procedural and recovery nurses ranked patient level of sedation on a –5 (markedly undersedated) to 5 (markedly oversedated) scale and patient discomfort on a 0 (none) to 10 (procedure aborted due to severe patient discomfort) scale. Sedation was administered to patients upon request or in those who had significant pain with IPMP in the past. For patients not receiving sedation, the PROSAS was altered for relevancy. For nonsedation patients, there was no procedure nurse, so that form was omitted, and the postprocedure physician and recovery nurse items directly related to sedation were removed; in the patient postprocedure form, for the question asking “If having this procedure again in the future, how much sedation would you prefer to have?” the response scale was changed from “markedly less sedation” to “markedly more sedation” to “none” to “asleep/heavily sedated.” There were no other differences in methodology between the sedated and nonsedated cohorts. Patient discomfort scales used in sedated and nonsedated patients were identical. Data Analysis Primary analysis was qualitative. For evaluation of predictors of sedation quality, the Student’s t test and Fishers exact test were used for continuous and categorical variables, respectively. Spearman’s Rho was used for correlation of linear data. Additionally, binary logistic regression was used to evaluate clinical factors independently related to risk of poor sedation quality. Statistical analysis was completed using SPSS for Windows (Rel. 19.0 2011; SPSS, Inc., Chicago, IL, USA). All authors had access to the study data and reviewed and approved the final manuscript. This study was approved by the Beth Israel Deaconess Medical Center Institution Review Board (IRB) and supported by a Clinical Innovation Award from the Center for Disease and Healthcare at Beth Israel Deaconess Medical Center. Results There were 155 patients evaluated for procedure-related pain with predominantly white ethnicity and an average age of 57 years, most often undergoing spinal injections (Table 1). Mean preprocedure discomfort level was 6.5 (range = 0–10) (Table 2). Mean patient-reported procedural pain intensity level was 3.5 (range = 0–10). The mean physician-rated procedure-related pain was slightly lower at a mean of 2.1 (range = 0–8) (P = 0.002). The mean postprocedure pain level reported was 3.7 (range = 0–10). There was no association of age, gender, or ethnicity with procedure-related pain. Nearly 43% of patients received opioids, with the majority on less than 50 mg morphine equivalents per day (MED). A significant proportion of patients received antidepressants (39.4%) and membrane-stabilizing agents (45.2%), with significantly less use of benzodiazepines (20.7%) and muscle relaxants (11.0%). There was a lack of procedural discomfort predictive value for any of these classes of medications including opioids. Active tobacco use (14.1%) also did not predict patient-reported procedural pain (P = 0.192). Lastly, no single intervention was determined to cause more procedural pain than another. Table 1 Patient characteristics Patient Characteristics  N = 155  Age (range), y  57.7 (19–91)  Female, %  62.5  Ethnicity, %     Asian  0.6   Black  11.6   Hispanic  7.7   White  78.1   Other/not specified  1.9  Procedure, %     Epidural  47.1   Facet joint injection  23.9   Sacroiliac  12.9   Sympathetic block  3.9   Peripheral nerve block  3.2   Bursa injection  3.2   Multiple interventions  2.6   Intra-articular joint injection  1.9   Intramuscular injection  1.3  Smoking status, %     Current smoker  14.1   Nonsmoker  46.5   Former smoker  27.7   Unknown  11.6  Received procedural sedation, %  6.5  Chronic treatments     Opioids  42.6   Benzodiazepines  20.7   Muscle relaxants  11.0   Antidepressants  39.4   Peripheral nerve agents  45.2  Patient Characteristics  N = 155  Age (range), y  57.7 (19–91)  Female, %  62.5  Ethnicity, %     Asian  0.6   Black  11.6   Hispanic  7.7   White  78.1   Other/not specified  1.9  Procedure, %     Epidural  47.1   Facet joint injection  23.9   Sacroiliac  12.9   Sympathetic block  3.9   Peripheral nerve block  3.2   Bursa injection  3.2   Multiple interventions  2.6   Intra-articular joint injection  1.9   Intramuscular injection  1.3  Smoking status, %     Current smoker  14.1   Nonsmoker  46.5   Former smoker  27.7   Unknown  11.6  Received procedural sedation, %  6.5  Chronic treatments     Opioids  42.6   Benzodiazepines  20.7   Muscle relaxants  11.0   Antidepressants  39.4   Peripheral nerve agents  45.2  Table 2 Average Pre and Post Procedure-related Pain Intensity   Mean Discomfort (Range)  Preprocedure discomfort  6.5 (0–10)  Procedural discomfort  3.5 (0–10)  Postprocedure discomfort  3.7 (0–10)  Physician-rated procedural discomfort  2.1 (0–8)  Pain     Epidural  3.3   Facet joint injection  3.7   Sacroiliac  3.6   Sympathetic block  3.3   Peripheral nerve block  2.3   Bursa injection  3.8   Multiple interventions  2.3   Intra-articular joint injection  4.0   Intramuscular injection  3.5    Mean Discomfort (Range)  Preprocedure discomfort  6.5 (0–10)  Procedural discomfort  3.5 (0–10)  Postprocedure discomfort  3.7 (0–10)  Physician-rated procedural discomfort  2.1 (0–8)  Pain     Epidural  3.3   Facet joint injection  3.7   Sacroiliac  3.6   Sympathetic block  3.3   Peripheral nerve block  2.3   Bursa injection  3.8   Multiple interventions  2.3   Intra-articular joint injection  4.0   Intramuscular injection  3.5  Table 3 lists the distribution of spinal interventions that were performed primarily in a nonsedated fashion. An average of 14.2% of patients experienced severe pain during the procedure. Only 10 patients received sedation in the form of midazolam, mean dose of 2.4 mg (range = 1–4 mg), and fentanyl, mean dose of 125 mcg (range = 50–200 mcg), with the majority (60%) still rating procedure-related pain as severe. None experienced adverse hemodynamic or respiratory adverse events. In addition, none of the patients undergoing nonspinal injections (Table 4) received sedation, representing the minority of overall injections. Up to 20% of these patients reported severe pain during the procedure, but this value was not statistically different from nonspinal (P = 0.504). Table 3 Patient discomfort with spine injections with and without sedation Spinal Injection Type  Total Number of Patients  Number of Patients (% Severe Pain) Without Sedation  Number of Patients (% Severe Pain) with Sedation  Epidural interventions: caudals, transforminal, interlaminar, and radiofrequency DRG procedures  74  7/72 (10)  1/2 (50)  Facet (cervical, thoracic, and lumbar) joint interventions: medial branch blocks, intra-articular blocks, and medial branch ablation  37  5/34 (15)  1/3 (33)  Sacroliac joint interventions: sacroiliac joint injections, lateral branch blocks, and radiofrequency  24  1/19 (5.3)  4/5 (80)  Total number of patients  135      Spinal Injection Type  Total Number of Patients  Number of Patients (% Severe Pain) Without Sedation  Number of Patients (% Severe Pain) with Sedation  Epidural interventions: caudals, transforminal, interlaminar, and radiofrequency DRG procedures  74  7/72 (10)  1/2 (50)  Facet (cervical, thoracic, and lumbar) joint interventions: medial branch blocks, intra-articular blocks, and medial branch ablation  37  5/34 (15)  1/3 (33)  Sacroliac joint interventions: sacroiliac joint injections, lateral branch blocks, and radiofrequency  24  1/19 (5.3)  4/5 (80)  Total number of patients  135      Table 4 Patient discomfort with nonspinal injections Injection Type  Total Number of Patients (% Severe Pain)  Sympathetic blocks: stellate ganglion block, ganglion impar block, superior hypogastric block, lumbar sympathetic block  6 (0)  Intra-articular joint injections: knee, hip, foot, coccygeal  3 (33.3)  Bursa injections: hip, shoulder  5 (0)  Peripheral nerve blocks: ilioinguinal, lateral femoral cutaneous nerve, genitofemoral, greater occipital nerve block and neuroms  5 (40)  Intramuscular injections: trigger points  1 (100)  Total  20 (20)  Injection Type  Total Number of Patients (% Severe Pain)  Sympathetic blocks: stellate ganglion block, ganglion impar block, superior hypogastric block, lumbar sympathetic block  6 (0)  Intra-articular joint injections: knee, hip, foot, coccygeal  3 (33.3)  Bursa injections: hip, shoulder  5 (0)  Peripheral nerve blocks: ilioinguinal, lateral femoral cutaneous nerve, genitofemoral, greater occipital nerve block and neuroms  5 (40)  Intramuscular injections: trigger points  1 (100)  Total  20 (20)  There is a strong correlation between physician- and patient-reported procedural discomfort (P < 0.001) (Table 5). Specifically, physicians best appreciated when a procedure did not seem to produce much discomfort. The ability to detect significant procedural pain by the physician was with a low kappa value (0.286), however, with physicians underestimating procedural discomfort. Table 5 Agreement between patient- and physician-reported procedural discomfort     Significant Procedural Pain Reported by Physician  Significant procedural pain reported by patient    Yes  No  Yes  22  38  No  9  79      Significant Procedural Pain Reported by Physician  Significant procedural pain reported by patient    Yes  No  Yes  22  38  No  9  79  Discussion The present study supports the current practice that the majority of patients tolerate routine IPMP procedures with local anesthetic infiltration only and do not experience severe pain. The data heavily reflect IPMP of the spine, but nonspinal IPMP seem to follow a similar trajectory. Thus the present data do not lend sustenance to the routine use of sedation for IPMP and would call for conservation of sedation services. When a patient does experience significant pain, it is common for the treating physician to underestimate this negative experience. Therefore, there was an attempt to determine if factors such as age, gender, ethnicity, smoking habits, preprocedure pain level, or medication classes (opioids, benzodiazepines, antidepressants, anti-epileptics, and skeletal muscle relaxants) may help identify this subgroup, but no correlation was found. While prior studies specifically focusing on pain sensitivity have found differences among ethnicities, age, and gender, the present study as well as Manabat et al., who analyzed pain responses to subcutaneous lidocaine injections, did not [1,9,10]. Active or prior tobacco use has been reported to be associated with greater pain intensity than never smokers, but no pattern was found in the present study [11,12]. There is inconsistency in the literature on the predictive value of chronic opioid therapy on pain levels following noxious stimuli, in particular subcutaneous lidocaine injections. Cohen et al. found higher levels of pain response, suggesting hyperalgesia in such patients, whereas Manabat et al. did not find any correlation [13,1]. Similarly, our study failed to demonstrate a correlation of discomfort and opioid use, but in both cases this may reflect lower daily doses of opioid medication (<50 MED), similar to Manabat et al. Wasan et al. [14] determined that hyperalgesic response during quantitative sensory testing was not predicted by opioid dose but correlated to pain-related distress (anxiety and catastrophizing) as well as high risk for opioid misuse. They concluded that these high-risk patients as determined by the Screener and Opioid Assessment for Patients with Pain–Revised (SOAPP-R) have consistently higher pain sensitivity independent of opioid dose. Risk stratification by SOAPP-R was not given to patients in this study to permit a similar analysis. Anxiety levels were not assessed in the present study but have been shown in prior studies to correlate with pain intensity [1,14]. Using the presence of a mood-stabilizing medication as a surrogate does not seem to work in the present study and may reflect the actual improvement rendered by these medications. A survey study on patients not routinely offered sedation undergoing primarily spinal injections demonstrated that only 17% requested procedural sedation for the first injection [6]. This number rose to 28% upon the need to perform a second intervention. Patients requesting sedation before proceeding with an injection were found to have higher anxiety levels, but the main reason for the request for sedation on the second intervention was procedural pain. A follow-up study by the same group liberally offered patients the choice of sedation prior to spinal injections and found that 58% of patients preferred sedation [7]. There was again significant correlation of sedation requests to anxiety levels but no measure of the impact of anxiety control on procedure-related pain. There is a strong suggestion that simply controlling anxiety would reduce procedure-related pain, but the full effectiveness of such a strategy needs further investigation [15]. Minimizing pain during IPMP can be thought of in terms of the procedural technique and methods of sedation. The prevalence of neuropathic pain as determined by neuropathic pain scales can result in hyperalgesia, particularly in chronic spinal conditions [16]. The resulting increased pain sensitivity can make ensuring procedural comfort challenging. Neuropathic scales were not administered during the present study that could potentially help identify those who may experience higher levels of pain. The painful attributes of a spinal injection include several phases of the procedure: 1) initial needle insertion and injection of local anesthetic (phase I), 2) manipulation and repositioning of the needle in deep tissue (phase II), and 3) injection of therapeutic medication (phase III, e.g., targeting an inflamed nerve root or synovial joint). In the literature, at least one study suggests that phase I has a strong association with overall postprocedure pain scores due to the initial noxious stimulation [17]. Both use of topical anesthetic cream (5% liposomal lidocaine) [18] and initial injection of local anesthetic into deeper subcutaneous tissues with minimal skin wheal [17] can help reduce phase I–related pain. Reducing the needle gauge from 22 to 25 may help further reduce phase II pain [17]. It is not clear if additional injection of local anesthetic prior to advancing the needle to deeper levels would enhance procedural comfort. There have been no studies on the optimal local anesthetic type or concentration for IPMP. Studies in other disciplines have suggested minimizing pain on local anesthetic injection by inserting the smallest appropriate gauge needle in a perpendicular manner and injecting bicarbonate buffered warmed lidocaine solution slowly [18–21]. Additional limitations of the current study are that it was not designed to address the impact of needle gauge, technique, or operator experience on patient comfort during IPMP. It is also possible that there exist differences among approaches to the epidural space (e.g., caudal vs interlaminar). The degree to which these modifications, as well as not addressing phase III, impact pain during IPMP requires further research. Sedation seems to be the most logical approach to ensure patient comfort and reduce anxiety levels during IPMP. There is certainly good support for the use of sedation for painful minimally invasive procedures, and this technique is commonly used in up to 90% of IPMP involving discograms and implantable therapies [22,5]. While the current study could not identify risk factors for significant procedural pain, anxiety measures or even the SOAPP-R may help isolate candidates. Although the current study had only 10 patients receiving conscious sedation, most did continue to experience severe pain, which is consistent with prior experiences with conscious sedation for spinal injections as well as other procedures such as colonoscopy [17,8]. These observations suggest that usual doses of fentanyl and midazolam or the agents themselves fall short of enhancing procedural comfort. Patients who receive sedation for IPMP may have high baseline anxiety and/or have the expectation of a relatively pain-free procedure, leading to a negative experience once such expectations are not met. The routine application of deeper sedation for IPMP is also not a clear option and has not been recommended on account of safety concerns [3]. Thus, there remains a knowledge gap as to which agents, and in what doses, can minimize pain while maintaining a safe level of consciousness. Conclusions The current study demonstrates that the majority of patients undergoing IPMP do not experience severe pain. A small but significant percentage of subjects experience significant procedural discomfort but cannot be risk-stratified by any clinical characteristics identified on standard clinical assessment or by the treating physician. Finally, it remains unclear if conscious sedation in the usual doses of fentanyl and midazolam ensures adequate patient comfort during IPMP. During IPMP, physicians can easily identify comfortable patients but underestimate the severity of pain in those individuals who experience significant discomfort. Appendix Procedural Sedation Assessment Survey Quality Improvement Questionnaire Procedure nurse (name): Please fold survey upon completion. Also, please note that in the case of double procedures, this survey is for overall comfort level. Procedure observations: Any episodes of O2 desaturation < 90% or leading to intervention? □ Yes □ No Any problematic changes in HR or BP during intervention? (e.g., SBP <90 >160; HR <50 >120) □ Yes □ No Any hemodynamic or respiratory conditions that interrupted the procedure? □ Yes □ No What level of sedation best describes the case overall? Markedly Undersedated  Somewhat Undersedated  Appropriate Sedation  Somewhat Oversedated  Markedly Oversedated  –5  –4  –3  –2  –1  0  1  2  3  4  5  Markedly Undersedated  Somewhat Undersedated  Appropriate Sedation  Somewhat Oversedated  Markedly Oversedated  –5  –4  –3  –2  –1  0  1  2  3  4  5  Examples of level of sedation Markedly Undersedated: Patient wide awake, in significant discomfort, causing procedure interruptions Somewhat Undersedated: Patient alert for part of procedure, transiently uncomfortable, requests additional sedation, no procedure interruptions Appropriately Sedated: No discomfort or anxiety during procedure, level of sedation consistent with patient preference, no hemodynamic/respiratory disturbance, patient able to respond to command Somewhat Oversedated: Patient arousable with difficulty, transient hemodynamic/respiratory disturbance not requiring intervention, prolonged recovery time Markedly Oversedated: Patient unarousable, hemodynamic/respiratory status require intervention, prolonged recovery time How much discomfort did the patient experience during the procedure? None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Procedure Aborted due to Patient Discomfort  0  1  2  3  4  5  6  7  8  9  10  None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Procedure Aborted due to Patient Discomfort  0  1  2  3  4  5  6  7  8  9  10  Please rate the patient’s cooperation during the procedure: □ Procedure aborted due to lack of cooperation □ Procedure delayed/interrupted due to lack of cooperation □ Adequately cooperative Physician (name): Other physician present: Please fold survey upon completion. Also, please note that in the case of double procedures, this survey is for overall comfort level. During the procedure: What level of sedation best describes the case overall? Markedly Undersedated  Somewhat Undersedated  Appropriate Sedation  Somewhat Oversedated  Markedly Oversedated  –5  –4  –3  –2  –1  0  1  2  3  4  5  Markedly Undersedated  Somewhat Undersedated  Appropriate Sedation  Somewhat Oversedated  Markedly Oversedated  –5  –4  –3  –2  –1  0  1  2  3  4  5  Examples of level of sedation Markedly Undersedated: Patient wide awake, in significant discomfort, causing procedure interruptions Somewhat Undersedated: Patient alert for part of procedure, transiently uncomfortable, requests additional sedation, no procedure interruptions Appropriately Sedated: No discomfort or anxiety during procedure, level of sedation consistent with patient preference, no hemodynamic/respiratory disturbance, patient able to respond to command Somewhat Oversedated: Patient arousable with difficulty, transient hemodynamic/respiratory disturbance not requiring intervention, prolonged recovery time Markedly Oversedated: Patient unarousable, hemodynamic/respiratory status require intervention, prolonged recovery time How much discomfort did the patient experience during the procedure? None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Procedure Aborted due to Patient Discomfort  0  1  2  3  4  5  6  7  8  9  10  None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Procedure Aborted due to Patient Discomfort  0  1  2  3  4  5  6  7  8  9  10  Please rate the patient’s cooperation during the procedure: □ Procedure aborted due to lack of cooperation □ Procedure delayed/interrupted due to lack of cooperation □ Adequately cooperative Was the exam interrupted in any way due to patient discomfort? □ Yes □ No Recovery nurse (name): Please indicate the amount of time patient spends in the recovery room: Time patient arrives in recovery room: _____________________ Time patient leaves recovery room: _____________________ How did procedural sedation impact patient recovery? Persistent Pain due to Undersedation  Minor Discomfort due to Undersedation  Optimal Recovery*  Slightly Sedated: Slow and Minor Difficulty in Attaining Awareness and Consciousness  Sedated: Difficulty in Attaining Awareness and Consciousness  –5  –4  –3  –2  –1  0  1  2  3  4  5  Persistent Pain due to Undersedation  Minor Discomfort due to Undersedation  Optimal Recovery*  Slightly Sedated: Slow and Minor Difficulty in Attaining Awareness and Consciousness  Sedated: Difficulty in Attaining Awareness and Consciousness  –5  –4  –3  –2  –1  0  1  2  3  4  5  *We define a patient with optimal recovery as one who is comfortable and without nausea in recovery and who is awake and ready to be discharged within 20–30 minutes postprocedure. Did the patient complain of any pain during recovery? □ Yes □ No Did the patient complain of any nausea during recovery? □ Yes □ No Other comments: Patient to complete the following survey by themselves, with a family member or a nurse immediately postprocedure. How much discomfort did you experience during the procedure? None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  If having this procedure again in the future, how much sedation would you prefer to have: Markedly Less Sedation  Somewhat Less Sedation  Same Amount of Sedation  Somewhat More Sedation  Markedly More Sedation  –5  –4  –3  –2  –1  0  1  2  3  4  5  Markedly Less Sedation  Somewhat Less Sedation  Same Amount of Sedation  Somewhat More Sedation  Markedly More Sedation  –5  –4  –3  –2  –1  0  1  2  3  4  5  On a scale of 0–10, how much pain were you feeling before the procedure? None  Slight Pain  Moderate Pain  Significant Pain  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  None  Slight Pain  Moderate Pain  Significant Pain  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  On a scale of 0–10, how much pain are you feeling now? None  Slight Pain  Moderate Pain  Significant Pain  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  None  Slight Pain  Moderate Pain  Significant Pain  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  Do you have any nausea now? □ Yes □ No Do you have any dizziness now? □ Yes □ No Do you have any fatigue/tiredness now? □ Yes □ No Other comments about your experience? For comments or questions, please contact ________________ at _________________________ Moderate Sedation Patient Readiness Survey Please complete this survey before your procedure 1. Have you ever received sedation for a procedure? □ Yes □ No 2. Do you feel that you received sufficient information about the procedure you are about to have? □ I received no information □ I received some information but would prefer more detailed information □ I received detailed and comprehensive information 3. How much pain are you experiencing now? 4. How much discomfort do you expect to experience during this procedure? None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Severe Discomfort  0  1  2  3  4  5  6  7  8  9  10  None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Severe Discomfort  0  1  2  3  4  5  6  7  8  9  10  5. What is the total amount of time before you are ready to go home after your procedure? □ <30 minutes  □ 30–60 minutes  □ 1–2 hours  □ >2 hours 6. How much time do you expect to pass before you feel fully recovered, similar to how you usually feel? □ 1–2 hours  □ 3–24 hours  □ 1–2 days  □ 3–5 days  □ 6–7 days 7. Please indicate other source(s) of your knowledge about the procedure: □ Family □ Friends □ Physician/nurse □ BIDMC website □ Personal experience □ Other;         if other, please specify __________________________________ 8. How would you prefer to be contacted for a follow-up survey? (Please select 1 option and PRINT CLEARLY). □ Email: ______________________________________________ □ Phone (number and time): ___________________________________ □ Postal mail (The nurse will give you a short survey in a prestamped envelope to be completed within 48 hours of your procedure) References 1 Manabat ER, Pujol LA, Hunt P, Wang D. Judging pain sensitivity with subcutaneous lidocaine injections. Pain Med  2011; 12: 668– 72. Google Scholar CrossRef Search ADS PubMed  2 Cohen SP, Mao J, Vu T, et al.   Does pain score in response to a standardized subcutaneous local anesthetic injection predict epidural steroid outcomes in patient with lumbosacral radiculopathy? A prospective correlational study. Pain Med  2013; 14: 327– 35. Google Scholar CrossRef Search ADS PubMed  3 Smith HS, Colson J, Sehgal N. Update of evaluation of intravenous sedation on diagnostic spinal injection procedures. 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Gastrointest Endosc  2015; 81: 194– 203. Google Scholar CrossRef Search ADS PubMed  9 Woodrow KM, Friedman GD, Siegelaub AB, Collen MR. Pain tolerance: Differences according to age, sex and race. Psychosom Med  1972; 34: 548– 56. Google Scholar CrossRef Search ADS PubMed  10 Auburn F, Salvi N, Coriat P, Riou B. Sex- and age-related differences in morphine requirements for post-operative pain relief. Anesthesiology  2005; 103: 156– 60. Google Scholar CrossRef Search ADS PubMed  11 John U, Hanke M, Meyer C, et al.   Tobacco smoking in relation to pain in a national general population survery. Prev Med  2006; 43: 477– 81. Google Scholar CrossRef Search ADS PubMed  12 Weingarten TN, Moeschler SM, Ptaszynski AE, et al.   An assessment of the association between smoking status, pain intensity, and functional interference in patients with chronic pain. Pain Physician  2008; 11 5: 643– 53. Google Scholar PubMed  13 Cohen S, Christo P, Wang, et al.   The effect of opioid dose and treatment duration on the perception of a painful standardized clinical stimulus. Reg Anesth Pain Med  2008; 33 3: 199– 206. Google Scholar CrossRef Search ADS PubMed  14 Wasan AD, Michna E, Greenbaum S, Ross EL, Jamison RN. Elevated pain sensitivity in chronic pain patient at risk for opioid misuse. J Pain  2011; 12 9: 953– 63. Google Scholar CrossRef Search ADS PubMed  15 McCracken LM, Keogh E. Acceptance, mindfulness, and values-based action may counteract fear and avoidance of emotions in chronic pain: An analysis of anxiety sensitivity. J Pain  2009; 10 4: 408– 15. Google Scholar CrossRef Search ADS PubMed  16 Kaki AM, El-Yaski AZ. Yousef E. Identifying neuropathic pain among patients with chronic low back pain. Use of the Leeds assessment of neuropathic symptoms and signs scale. Reg Anesth Pain Med  2005; 30: 422– 8. Google Scholar PubMed  17 Bakshi R, Berri H, Kalpakjian C, Smuck M. The effects of local anesthesia administration on pain experiences during interventional spine procedures: A prospective controlled trial. Pain Med  2016; 17: 488– 93. Google Scholar PubMed  18 Palmon SC, Lloyd AT, Kirsch JR. The effect of needle gauge and lidocaine pH on pain during intradermal injection. Anesth Analg  1998; 86: 379– 81. Google Scholar PubMed  19 Martires KJ, Malbasa CL, Bordeaux JS. A randomized controlled crossover trial: Lidocaine injected at a 90-degree angle causes less pain than lidocaine injected at a 45-degree angle. J Am Acad Dermatol  2011; 66: 1231– 3. Google Scholar CrossRef Search ADS   20 Scarfone RJ, Jasani M, Gracely EJ. Pain of local anesthetics: Rate of administration and buffering. Ann Emerg Med  1998; 31: 36– 40. Google Scholar CrossRef Search ADS PubMed  21 Hogan ME, vanderVaart S, Perapaladas K, et al.   Systematic review and meta-analysis of the effect of warming local anesthetics on injection pain. Ann Emerg Med  2011; 58: 86– 98.e1. Google Scholar CrossRef Search ADS PubMed  22 Jones DR, Salgo P, Meltzer J. Videos in clinical medicine. Conscious sedation for minor procedures in adults. N Engl J Med  2011; 364: e54. Google Scholar CrossRef Search ADS PubMed  © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Pain Medicine Oxford University Press

Prospective Assessment of Pain and Comfort in Chronic Pain Patients Undergoing Interventional Pain Management Procedures

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Blackwell Publishing Inc.
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© 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
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1526-2375
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1526-4637
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10.1093/pm/pnx064
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Abstract

Abstract Objective Interventional pain management procedures have an important role in the management of chronic pain. The present study seeks to identify the proportion of patients who experience severe pain during pain procedures either with or without sedation. There is then an attempt to identify any association of high pain levels with factors such as age, gender, ethnicity, preprocedure pain level, procedure type, tobacco use, and baseline pharmaceuticals taken for both pain and/or mood disorder management. Methods This is a prospective survey study evaluating patients’ discomfort during interventional pain procedures in an outpatient academic facility. Patient discomfort was assessed by the PROcedural Sedation Assessment Survey (PROSAS) and modified for nonsedation cases. Results There were 155 patients in the survey, with 20 of these receiving nonspinal injections. Of the remaining 135 patients who underwent spinal injections, only 10 received conscious sedation. On average, 14.2% experienced severe pain during spinal injections, whereas 20% experienced severe pain with nonspinal injections. Though few patients received conscious sedation, most of these (60%) experienced high levels of pain. There was no correlation between level of procedural pain with age, gender, ethnicity, preprocedure pain level, procedure type, tobacco use, or medication type used. Conclusions The majority of patients who undergo nonsedated interventional pain management procedures do not experience severe pain. There is a small but appreciable group of subjects who seem to experience severe pain that cannot be correlated to any particular clinical characteristic in a standard patient evaluation. Even with standard conscious sedation, there is no clear best method to ensure patient comfort for this high–pain level group. Interventional Pain Management Procedures, Pain, Procedural Discomfort Introduction Interventional pain management procedures (IPMP) have become an integral component in the comprehensive approach for the management of intractable chronic pain. IPMP are conducted in a variety of clinical settings, which include physicians’ offices, hospital procedural suites, ambulatory surgery centers, and operating rooms. There are pain practitioners of both anesthesia and nonanesthesia currently performing interventional techniques. There is, however, little insight as to how comfortable chronic pain patients are during these procedures. Furthermore, there is no approach put forth to identify patients prior to IPMP who may be at risk for increased levels of pain. The injection of local anesthetic, lidocaine, is anecdotally regarded as the most painful aspect of IPMP. The response to local anesthetic injection has been suggested at least in one study to predict pain sensitivity [1]. Indeed, higher pain scores after subcutaneous lidocaine injection correlate with increased anxiety and body movement during needle placement [1]. High levels of pain during lidocaine infiltration have a weak correlation to negative short-term outcomes with lumbar epidural steroid injections to treat painful lumbosacral radiculopathy [2]. Practically, the determination of pain levels after the injection of local anesthetic does not help the clinician plan ahead so as to ensure patient comfort. In general, the use of deep sedation to mitigate patient discomfort especially in an indiscriminate fashion has been discouraged [3]. The loss of the ability of a patient to report increased pain and paresthesias, especially during cervical IPMP, may predispose to significant neurological injury [4]. Not surprising, intravenous (IV) sedation use varies widely across the United States, with a mean of 64% across all IPMP [5]. Previous studies identified anxiety as a key factor driving oral sedation requests in 28% to 58% of patients undergoing spinal injections and recommended against the routine use of sedation [6,7]. While anxiety reduces pain tolerance, direct assessment of pain was not performed in either study. Recognizing the observational fact that some patients can experience severe pain during IPMP despite local anesthetic infiltration, there is a need to explore factors that might help to identify these individuals. The primary aim of the present study was to prospectively determine procedure-related discomfort as rated by both the patient and physician proceduralist. A subgroup analysis in patients who experience high levels of pain was then performed to determine if any correlation exists with known clinical characteristics. Methods Study Design and Patient Selection This is a prospective survey evaluation of pain during IPMP in a tertiary care center outpatient procedural facility. The proceduralist and the patient filled out survey forms for determining procedure-related pain in the absence of sedation. In cases of conscious sedation, an additional form was completed by the nurse administering the sedatives midazolam and fentanyl. The exclusion criterion for the study was insufficient understanding of the English language to complete the survey form. Data Collection All patients enrolled in the survey had the following baseline demographic data including age, gender, ethnicity, preprocedure pain level, procedure type, and tobacco use. In addition, the relevant medications that include antidepressants, membrane-stabilizing agents, benzodiazepines, skeletal muscle relaxants, and morphine equivalent dose of opioids consumed (three months of opioid use or greater) were recorded. The survey form used was the PROcedural Sedation Assessment Survey (PROSAS) (Appendix) [8]. The PROSAS is a clinically relevant, patient-centered questionnaire that specifically addresses periprocedural discomfort. Specifically, The PROSAS includes pre-intra- and postprocedure questions of pain severity completed by patients. This questionnaire also inquires on the adequacy of sedation. The PROSAS also includes intraprocedural pain assessment from both the physician performing the procedure and the nurse administering the sedation. PROSAS rates patient comfort on a 0 (no pain) to 10 (severe pain) scale and satisfaction with sedation level on –5 (markedly less sedation then wanted) to +5 (markedly more sedation then wanted) scale. Physicians, procedural and recovery area nurses were also asked to complete a brief survey addressing the quality of sedation and assessment of patient discomfort. Procedural nurses reported sedation events, which were defined as any case with one or more of the following: 1) any episodes of oxygen desaturation of less than 90% or leading to intervention, 2) any problematic changes in heart rate or blood pressure during intervention (systolic blood pressure < 90 or >160; heart rate <50 or >120), 3) any hemodynamic or respiratory conditions that interrupted the procedure, 4) use of opioids or benzodiazepine reversal agents, 5) hospitalization because of an adverse event of sedation. All sedation-related adverse events were recorded at the time of the procedure. In addition, procedural and recovery nurses ranked patient level of sedation on a –5 (markedly undersedated) to 5 (markedly oversedated) scale and patient discomfort on a 0 (none) to 10 (procedure aborted due to severe patient discomfort) scale. Sedation was administered to patients upon request or in those who had significant pain with IPMP in the past. For patients not receiving sedation, the PROSAS was altered for relevancy. For nonsedation patients, there was no procedure nurse, so that form was omitted, and the postprocedure physician and recovery nurse items directly related to sedation were removed; in the patient postprocedure form, for the question asking “If having this procedure again in the future, how much sedation would you prefer to have?” the response scale was changed from “markedly less sedation” to “markedly more sedation” to “none” to “asleep/heavily sedated.” There were no other differences in methodology between the sedated and nonsedated cohorts. Patient discomfort scales used in sedated and nonsedated patients were identical. Data Analysis Primary analysis was qualitative. For evaluation of predictors of sedation quality, the Student’s t test and Fishers exact test were used for continuous and categorical variables, respectively. Spearman’s Rho was used for correlation of linear data. Additionally, binary logistic regression was used to evaluate clinical factors independently related to risk of poor sedation quality. Statistical analysis was completed using SPSS for Windows (Rel. 19.0 2011; SPSS, Inc., Chicago, IL, USA). All authors had access to the study data and reviewed and approved the final manuscript. This study was approved by the Beth Israel Deaconess Medical Center Institution Review Board (IRB) and supported by a Clinical Innovation Award from the Center for Disease and Healthcare at Beth Israel Deaconess Medical Center. Results There were 155 patients evaluated for procedure-related pain with predominantly white ethnicity and an average age of 57 years, most often undergoing spinal injections (Table 1). Mean preprocedure discomfort level was 6.5 (range = 0–10) (Table 2). Mean patient-reported procedural pain intensity level was 3.5 (range = 0–10). The mean physician-rated procedure-related pain was slightly lower at a mean of 2.1 (range = 0–8) (P = 0.002). The mean postprocedure pain level reported was 3.7 (range = 0–10). There was no association of age, gender, or ethnicity with procedure-related pain. Nearly 43% of patients received opioids, with the majority on less than 50 mg morphine equivalents per day (MED). A significant proportion of patients received antidepressants (39.4%) and membrane-stabilizing agents (45.2%), with significantly less use of benzodiazepines (20.7%) and muscle relaxants (11.0%). There was a lack of procedural discomfort predictive value for any of these classes of medications including opioids. Active tobacco use (14.1%) also did not predict patient-reported procedural pain (P = 0.192). Lastly, no single intervention was determined to cause more procedural pain than another. Table 1 Patient characteristics Patient Characteristics  N = 155  Age (range), y  57.7 (19–91)  Female, %  62.5  Ethnicity, %     Asian  0.6   Black  11.6   Hispanic  7.7   White  78.1   Other/not specified  1.9  Procedure, %     Epidural  47.1   Facet joint injection  23.9   Sacroiliac  12.9   Sympathetic block  3.9   Peripheral nerve block  3.2   Bursa injection  3.2   Multiple interventions  2.6   Intra-articular joint injection  1.9   Intramuscular injection  1.3  Smoking status, %     Current smoker  14.1   Nonsmoker  46.5   Former smoker  27.7   Unknown  11.6  Received procedural sedation, %  6.5  Chronic treatments     Opioids  42.6   Benzodiazepines  20.7   Muscle relaxants  11.0   Antidepressants  39.4   Peripheral nerve agents  45.2  Patient Characteristics  N = 155  Age (range), y  57.7 (19–91)  Female, %  62.5  Ethnicity, %     Asian  0.6   Black  11.6   Hispanic  7.7   White  78.1   Other/not specified  1.9  Procedure, %     Epidural  47.1   Facet joint injection  23.9   Sacroiliac  12.9   Sympathetic block  3.9   Peripheral nerve block  3.2   Bursa injection  3.2   Multiple interventions  2.6   Intra-articular joint injection  1.9   Intramuscular injection  1.3  Smoking status, %     Current smoker  14.1   Nonsmoker  46.5   Former smoker  27.7   Unknown  11.6  Received procedural sedation, %  6.5  Chronic treatments     Opioids  42.6   Benzodiazepines  20.7   Muscle relaxants  11.0   Antidepressants  39.4   Peripheral nerve agents  45.2  Table 2 Average Pre and Post Procedure-related Pain Intensity   Mean Discomfort (Range)  Preprocedure discomfort  6.5 (0–10)  Procedural discomfort  3.5 (0–10)  Postprocedure discomfort  3.7 (0–10)  Physician-rated procedural discomfort  2.1 (0–8)  Pain     Epidural  3.3   Facet joint injection  3.7   Sacroiliac  3.6   Sympathetic block  3.3   Peripheral nerve block  2.3   Bursa injection  3.8   Multiple interventions  2.3   Intra-articular joint injection  4.0   Intramuscular injection  3.5    Mean Discomfort (Range)  Preprocedure discomfort  6.5 (0–10)  Procedural discomfort  3.5 (0–10)  Postprocedure discomfort  3.7 (0–10)  Physician-rated procedural discomfort  2.1 (0–8)  Pain     Epidural  3.3   Facet joint injection  3.7   Sacroiliac  3.6   Sympathetic block  3.3   Peripheral nerve block  2.3   Bursa injection  3.8   Multiple interventions  2.3   Intra-articular joint injection  4.0   Intramuscular injection  3.5  Table 3 lists the distribution of spinal interventions that were performed primarily in a nonsedated fashion. An average of 14.2% of patients experienced severe pain during the procedure. Only 10 patients received sedation in the form of midazolam, mean dose of 2.4 mg (range = 1–4 mg), and fentanyl, mean dose of 125 mcg (range = 50–200 mcg), with the majority (60%) still rating procedure-related pain as severe. None experienced adverse hemodynamic or respiratory adverse events. In addition, none of the patients undergoing nonspinal injections (Table 4) received sedation, representing the minority of overall injections. Up to 20% of these patients reported severe pain during the procedure, but this value was not statistically different from nonspinal (P = 0.504). Table 3 Patient discomfort with spine injections with and without sedation Spinal Injection Type  Total Number of Patients  Number of Patients (% Severe Pain) Without Sedation  Number of Patients (% Severe Pain) with Sedation  Epidural interventions: caudals, transforminal, interlaminar, and radiofrequency DRG procedures  74  7/72 (10)  1/2 (50)  Facet (cervical, thoracic, and lumbar) joint interventions: medial branch blocks, intra-articular blocks, and medial branch ablation  37  5/34 (15)  1/3 (33)  Sacroliac joint interventions: sacroiliac joint injections, lateral branch blocks, and radiofrequency  24  1/19 (5.3)  4/5 (80)  Total number of patients  135      Spinal Injection Type  Total Number of Patients  Number of Patients (% Severe Pain) Without Sedation  Number of Patients (% Severe Pain) with Sedation  Epidural interventions: caudals, transforminal, interlaminar, and radiofrequency DRG procedures  74  7/72 (10)  1/2 (50)  Facet (cervical, thoracic, and lumbar) joint interventions: medial branch blocks, intra-articular blocks, and medial branch ablation  37  5/34 (15)  1/3 (33)  Sacroliac joint interventions: sacroiliac joint injections, lateral branch blocks, and radiofrequency  24  1/19 (5.3)  4/5 (80)  Total number of patients  135      Table 4 Patient discomfort with nonspinal injections Injection Type  Total Number of Patients (% Severe Pain)  Sympathetic blocks: stellate ganglion block, ganglion impar block, superior hypogastric block, lumbar sympathetic block  6 (0)  Intra-articular joint injections: knee, hip, foot, coccygeal  3 (33.3)  Bursa injections: hip, shoulder  5 (0)  Peripheral nerve blocks: ilioinguinal, lateral femoral cutaneous nerve, genitofemoral, greater occipital nerve block and neuroms  5 (40)  Intramuscular injections: trigger points  1 (100)  Total  20 (20)  Injection Type  Total Number of Patients (% Severe Pain)  Sympathetic blocks: stellate ganglion block, ganglion impar block, superior hypogastric block, lumbar sympathetic block  6 (0)  Intra-articular joint injections: knee, hip, foot, coccygeal  3 (33.3)  Bursa injections: hip, shoulder  5 (0)  Peripheral nerve blocks: ilioinguinal, lateral femoral cutaneous nerve, genitofemoral, greater occipital nerve block and neuroms  5 (40)  Intramuscular injections: trigger points  1 (100)  Total  20 (20)  There is a strong correlation between physician- and patient-reported procedural discomfort (P < 0.001) (Table 5). Specifically, physicians best appreciated when a procedure did not seem to produce much discomfort. The ability to detect significant procedural pain by the physician was with a low kappa value (0.286), however, with physicians underestimating procedural discomfort. Table 5 Agreement between patient- and physician-reported procedural discomfort     Significant Procedural Pain Reported by Physician  Significant procedural pain reported by patient    Yes  No  Yes  22  38  No  9  79      Significant Procedural Pain Reported by Physician  Significant procedural pain reported by patient    Yes  No  Yes  22  38  No  9  79  Discussion The present study supports the current practice that the majority of patients tolerate routine IPMP procedures with local anesthetic infiltration only and do not experience severe pain. The data heavily reflect IPMP of the spine, but nonspinal IPMP seem to follow a similar trajectory. Thus the present data do not lend sustenance to the routine use of sedation for IPMP and would call for conservation of sedation services. When a patient does experience significant pain, it is common for the treating physician to underestimate this negative experience. Therefore, there was an attempt to determine if factors such as age, gender, ethnicity, smoking habits, preprocedure pain level, or medication classes (opioids, benzodiazepines, antidepressants, anti-epileptics, and skeletal muscle relaxants) may help identify this subgroup, but no correlation was found. While prior studies specifically focusing on pain sensitivity have found differences among ethnicities, age, and gender, the present study as well as Manabat et al., who analyzed pain responses to subcutaneous lidocaine injections, did not [1,9,10]. Active or prior tobacco use has been reported to be associated with greater pain intensity than never smokers, but no pattern was found in the present study [11,12]. There is inconsistency in the literature on the predictive value of chronic opioid therapy on pain levels following noxious stimuli, in particular subcutaneous lidocaine injections. Cohen et al. found higher levels of pain response, suggesting hyperalgesia in such patients, whereas Manabat et al. did not find any correlation [13,1]. Similarly, our study failed to demonstrate a correlation of discomfort and opioid use, but in both cases this may reflect lower daily doses of opioid medication (<50 MED), similar to Manabat et al. Wasan et al. [14] determined that hyperalgesic response during quantitative sensory testing was not predicted by opioid dose but correlated to pain-related distress (anxiety and catastrophizing) as well as high risk for opioid misuse. They concluded that these high-risk patients as determined by the Screener and Opioid Assessment for Patients with Pain–Revised (SOAPP-R) have consistently higher pain sensitivity independent of opioid dose. Risk stratification by SOAPP-R was not given to patients in this study to permit a similar analysis. Anxiety levels were not assessed in the present study but have been shown in prior studies to correlate with pain intensity [1,14]. Using the presence of a mood-stabilizing medication as a surrogate does not seem to work in the present study and may reflect the actual improvement rendered by these medications. A survey study on patients not routinely offered sedation undergoing primarily spinal injections demonstrated that only 17% requested procedural sedation for the first injection [6]. This number rose to 28% upon the need to perform a second intervention. Patients requesting sedation before proceeding with an injection were found to have higher anxiety levels, but the main reason for the request for sedation on the second intervention was procedural pain. A follow-up study by the same group liberally offered patients the choice of sedation prior to spinal injections and found that 58% of patients preferred sedation [7]. There was again significant correlation of sedation requests to anxiety levels but no measure of the impact of anxiety control on procedure-related pain. There is a strong suggestion that simply controlling anxiety would reduce procedure-related pain, but the full effectiveness of such a strategy needs further investigation [15]. Minimizing pain during IPMP can be thought of in terms of the procedural technique and methods of sedation. The prevalence of neuropathic pain as determined by neuropathic pain scales can result in hyperalgesia, particularly in chronic spinal conditions [16]. The resulting increased pain sensitivity can make ensuring procedural comfort challenging. Neuropathic scales were not administered during the present study that could potentially help identify those who may experience higher levels of pain. The painful attributes of a spinal injection include several phases of the procedure: 1) initial needle insertion and injection of local anesthetic (phase I), 2) manipulation and repositioning of the needle in deep tissue (phase II), and 3) injection of therapeutic medication (phase III, e.g., targeting an inflamed nerve root or synovial joint). In the literature, at least one study suggests that phase I has a strong association with overall postprocedure pain scores due to the initial noxious stimulation [17]. Both use of topical anesthetic cream (5% liposomal lidocaine) [18] and initial injection of local anesthetic into deeper subcutaneous tissues with minimal skin wheal [17] can help reduce phase I–related pain. Reducing the needle gauge from 22 to 25 may help further reduce phase II pain [17]. It is not clear if additional injection of local anesthetic prior to advancing the needle to deeper levels would enhance procedural comfort. There have been no studies on the optimal local anesthetic type or concentration for IPMP. Studies in other disciplines have suggested minimizing pain on local anesthetic injection by inserting the smallest appropriate gauge needle in a perpendicular manner and injecting bicarbonate buffered warmed lidocaine solution slowly [18–21]. Additional limitations of the current study are that it was not designed to address the impact of needle gauge, technique, or operator experience on patient comfort during IPMP. It is also possible that there exist differences among approaches to the epidural space (e.g., caudal vs interlaminar). The degree to which these modifications, as well as not addressing phase III, impact pain during IPMP requires further research. Sedation seems to be the most logical approach to ensure patient comfort and reduce anxiety levels during IPMP. There is certainly good support for the use of sedation for painful minimally invasive procedures, and this technique is commonly used in up to 90% of IPMP involving discograms and implantable therapies [22,5]. While the current study could not identify risk factors for significant procedural pain, anxiety measures or even the SOAPP-R may help isolate candidates. Although the current study had only 10 patients receiving conscious sedation, most did continue to experience severe pain, which is consistent with prior experiences with conscious sedation for spinal injections as well as other procedures such as colonoscopy [17,8]. These observations suggest that usual doses of fentanyl and midazolam or the agents themselves fall short of enhancing procedural comfort. Patients who receive sedation for IPMP may have high baseline anxiety and/or have the expectation of a relatively pain-free procedure, leading to a negative experience once such expectations are not met. The routine application of deeper sedation for IPMP is also not a clear option and has not been recommended on account of safety concerns [3]. Thus, there remains a knowledge gap as to which agents, and in what doses, can minimize pain while maintaining a safe level of consciousness. Conclusions The current study demonstrates that the majority of patients undergoing IPMP do not experience severe pain. A small but significant percentage of subjects experience significant procedural discomfort but cannot be risk-stratified by any clinical characteristics identified on standard clinical assessment or by the treating physician. Finally, it remains unclear if conscious sedation in the usual doses of fentanyl and midazolam ensures adequate patient comfort during IPMP. During IPMP, physicians can easily identify comfortable patients but underestimate the severity of pain in those individuals who experience significant discomfort. Appendix Procedural Sedation Assessment Survey Quality Improvement Questionnaire Procedure nurse (name): Please fold survey upon completion. Also, please note that in the case of double procedures, this survey is for overall comfort level. Procedure observations: Any episodes of O2 desaturation < 90% or leading to intervention? □ Yes □ No Any problematic changes in HR or BP during intervention? (e.g., SBP <90 >160; HR <50 >120) □ Yes □ No Any hemodynamic or respiratory conditions that interrupted the procedure? □ Yes □ No What level of sedation best describes the case overall? Markedly Undersedated  Somewhat Undersedated  Appropriate Sedation  Somewhat Oversedated  Markedly Oversedated  –5  –4  –3  –2  –1  0  1  2  3  4  5  Markedly Undersedated  Somewhat Undersedated  Appropriate Sedation  Somewhat Oversedated  Markedly Oversedated  –5  –4  –3  –2  –1  0  1  2  3  4  5  Examples of level of sedation Markedly Undersedated: Patient wide awake, in significant discomfort, causing procedure interruptions Somewhat Undersedated: Patient alert for part of procedure, transiently uncomfortable, requests additional sedation, no procedure interruptions Appropriately Sedated: No discomfort or anxiety during procedure, level of sedation consistent with patient preference, no hemodynamic/respiratory disturbance, patient able to respond to command Somewhat Oversedated: Patient arousable with difficulty, transient hemodynamic/respiratory disturbance not requiring intervention, prolonged recovery time Markedly Oversedated: Patient unarousable, hemodynamic/respiratory status require intervention, prolonged recovery time How much discomfort did the patient experience during the procedure? None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Procedure Aborted due to Patient Discomfort  0  1  2  3  4  5  6  7  8  9  10  None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Procedure Aborted due to Patient Discomfort  0  1  2  3  4  5  6  7  8  9  10  Please rate the patient’s cooperation during the procedure: □ Procedure aborted due to lack of cooperation □ Procedure delayed/interrupted due to lack of cooperation □ Adequately cooperative Physician (name): Other physician present: Please fold survey upon completion. Also, please note that in the case of double procedures, this survey is for overall comfort level. During the procedure: What level of sedation best describes the case overall? Markedly Undersedated  Somewhat Undersedated  Appropriate Sedation  Somewhat Oversedated  Markedly Oversedated  –5  –4  –3  –2  –1  0  1  2  3  4  5  Markedly Undersedated  Somewhat Undersedated  Appropriate Sedation  Somewhat Oversedated  Markedly Oversedated  –5  –4  –3  –2  –1  0  1  2  3  4  5  Examples of level of sedation Markedly Undersedated: Patient wide awake, in significant discomfort, causing procedure interruptions Somewhat Undersedated: Patient alert for part of procedure, transiently uncomfortable, requests additional sedation, no procedure interruptions Appropriately Sedated: No discomfort or anxiety during procedure, level of sedation consistent with patient preference, no hemodynamic/respiratory disturbance, patient able to respond to command Somewhat Oversedated: Patient arousable with difficulty, transient hemodynamic/respiratory disturbance not requiring intervention, prolonged recovery time Markedly Oversedated: Patient unarousable, hemodynamic/respiratory status require intervention, prolonged recovery time How much discomfort did the patient experience during the procedure? None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Procedure Aborted due to Patient Discomfort  0  1  2  3  4  5  6  7  8  9  10  None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Procedure Aborted due to Patient Discomfort  0  1  2  3  4  5  6  7  8  9  10  Please rate the patient’s cooperation during the procedure: □ Procedure aborted due to lack of cooperation □ Procedure delayed/interrupted due to lack of cooperation □ Adequately cooperative Was the exam interrupted in any way due to patient discomfort? □ Yes □ No Recovery nurse (name): Please indicate the amount of time patient spends in the recovery room: Time patient arrives in recovery room: _____________________ Time patient leaves recovery room: _____________________ How did procedural sedation impact patient recovery? Persistent Pain due to Undersedation  Minor Discomfort due to Undersedation  Optimal Recovery*  Slightly Sedated: Slow and Minor Difficulty in Attaining Awareness and Consciousness  Sedated: Difficulty in Attaining Awareness and Consciousness  –5  –4  –3  –2  –1  0  1  2  3  4  5  Persistent Pain due to Undersedation  Minor Discomfort due to Undersedation  Optimal Recovery*  Slightly Sedated: Slow and Minor Difficulty in Attaining Awareness and Consciousness  Sedated: Difficulty in Attaining Awareness and Consciousness  –5  –4  –3  –2  –1  0  1  2  3  4  5  *We define a patient with optimal recovery as one who is comfortable and without nausea in recovery and who is awake and ready to be discharged within 20–30 minutes postprocedure. Did the patient complain of any pain during recovery? □ Yes □ No Did the patient complain of any nausea during recovery? □ Yes □ No Other comments: Patient to complete the following survey by themselves, with a family member or a nurse immediately postprocedure. How much discomfort did you experience during the procedure? None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  If having this procedure again in the future, how much sedation would you prefer to have: Markedly Less Sedation  Somewhat Less Sedation  Same Amount of Sedation  Somewhat More Sedation  Markedly More Sedation  –5  –4  –3  –2  –1  0  1  2  3  4  5  Markedly Less Sedation  Somewhat Less Sedation  Same Amount of Sedation  Somewhat More Sedation  Markedly More Sedation  –5  –4  –3  –2  –1  0  1  2  3  4  5  On a scale of 0–10, how much pain were you feeling before the procedure? None  Slight Pain  Moderate Pain  Significant Pain  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  None  Slight Pain  Moderate Pain  Significant Pain  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  On a scale of 0–10, how much pain are you feeling now? None  Slight Pain  Moderate Pain  Significant Pain  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  None  Slight Pain  Moderate Pain  Significant Pain  Severe Pain  0  1  2  3  4  5  6  7  8  9  10  Do you have any nausea now? □ Yes □ No Do you have any dizziness now? □ Yes □ No Do you have any fatigue/tiredness now? □ Yes □ No Other comments about your experience? For comments or questions, please contact ________________ at _________________________ Moderate Sedation Patient Readiness Survey Please complete this survey before your procedure 1. Have you ever received sedation for a procedure? □ Yes □ No 2. Do you feel that you received sufficient information about the procedure you are about to have? □ I received no information □ I received some information but would prefer more detailed information □ I received detailed and comprehensive information 3. How much pain are you experiencing now? 4. How much discomfort do you expect to experience during this procedure? None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Severe Discomfort  0  1  2  3  4  5  6  7  8  9  10  None  Slight Discomfort  Moderate Discomfort  Significant Discomfort  Severe Discomfort  0  1  2  3  4  5  6  7  8  9  10  5. What is the total amount of time before you are ready to go home after your procedure? □ <30 minutes  □ 30–60 minutes  □ 1–2 hours  □ >2 hours 6. How much time do you expect to pass before you feel fully recovered, similar to how you usually feel? □ 1–2 hours  □ 3–24 hours  □ 1–2 days  □ 3–5 days  □ 6–7 days 7. Please indicate other source(s) of your knowledge about the procedure: □ Family □ Friends □ Physician/nurse □ BIDMC website □ Personal experience □ Other;         if other, please specify __________________________________ 8. How would you prefer to be contacted for a follow-up survey? (Please select 1 option and PRINT CLEARLY). □ Email: ______________________________________________ □ Phone (number and time): ___________________________________ □ Postal mail (The nurse will give you a short survey in a prestamped envelope to be completed within 48 hours of your procedure) References 1 Manabat ER, Pujol LA, Hunt P, Wang D. Judging pain sensitivity with subcutaneous lidocaine injections. Pain Med  2011; 12: 668– 72. Google Scholar CrossRef Search ADS PubMed  2 Cohen SP, Mao J, Vu T, et al.   Does pain score in response to a standardized subcutaneous local anesthetic injection predict epidural steroid outcomes in patient with lumbosacral radiculopathy? A prospective correlational study. Pain Med  2013; 14: 327– 35. Google Scholar CrossRef Search ADS PubMed  3 Smith HS, Colson J, Sehgal N. Update of evaluation of intravenous sedation on diagnostic spinal injection procedures. 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Google Scholar PubMed  13 Cohen S, Christo P, Wang, et al.   The effect of opioid dose and treatment duration on the perception of a painful standardized clinical stimulus. Reg Anesth Pain Med  2008; 33 3: 199– 206. Google Scholar CrossRef Search ADS PubMed  14 Wasan AD, Michna E, Greenbaum S, Ross EL, Jamison RN. Elevated pain sensitivity in chronic pain patient at risk for opioid misuse. J Pain  2011; 12 9: 953– 63. Google Scholar CrossRef Search ADS PubMed  15 McCracken LM, Keogh E. Acceptance, mindfulness, and values-based action may counteract fear and avoidance of emotions in chronic pain: An analysis of anxiety sensitivity. J Pain  2009; 10 4: 408– 15. Google Scholar CrossRef Search ADS PubMed  16 Kaki AM, El-Yaski AZ. Yousef E. Identifying neuropathic pain among patients with chronic low back pain. Use of the Leeds assessment of neuropathic symptoms and signs scale. Reg Anesth Pain Med  2005; 30: 422– 8. Google Scholar PubMed  17 Bakshi R, Berri H, Kalpakjian C, Smuck M. The effects of local anesthesia administration on pain experiences during interventional spine procedures: A prospective controlled trial. Pain Med  2016; 17: 488– 93. Google Scholar PubMed  18 Palmon SC, Lloyd AT, Kirsch JR. The effect of needle gauge and lidocaine pH on pain during intradermal injection. Anesth Analg  1998; 86: 379– 81. Google Scholar PubMed  19 Martires KJ, Malbasa CL, Bordeaux JS. A randomized controlled crossover trial: Lidocaine injected at a 90-degree angle causes less pain than lidocaine injected at a 45-degree angle. J Am Acad Dermatol  2011; 66: 1231– 3. Google Scholar CrossRef Search ADS   20 Scarfone RJ, Jasani M, Gracely EJ. Pain of local anesthetics: Rate of administration and buffering. Ann Emerg Med  1998; 31: 36– 40. Google Scholar CrossRef Search ADS PubMed  21 Hogan ME, vanderVaart S, Perapaladas K, et al.   Systematic review and meta-analysis of the effect of warming local anesthetics on injection pain. Ann Emerg Med  2011; 58: 86– 98.e1. 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Pain MedicineOxford University Press

Published: Feb 1, 2018

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