Canadian Journal of Anesthesia/Journal canadien d anesthésie

Au, Anthony S. W.; Evans, David; Crago, Ronald; Jones, William M.

doi: 10.1007/bf03005102pmid: 871934

SummaryHypertensive responses during operations on the abdominal aorta are common. We have shown that hypertensive changes occur before cross-clamping of the aorta. We have also shown that droperidol modifies the hypertensive changes in operations on the lower aorta. Although further studies are required, our preliminary results show a higher rise of serum epinephrine and norepinephrine levels in one patient receiving morphine, as compared to one patient receiving the same close per unit body weight of morphine plus droperidol. With maintenance of adequate pre-operative hydration and intra-operative fluid and blood replacement, declamping hypotension was transient in both groups of our patients.

Skovsted, Per; Sapthavichaikul, Sanguan

doi: 10.1007/bf03005103pmid: 871935

SummaryThe effects of isoflurane on arterial pressure, preganglionic sympathetic activity, vagal nervous activity, pulse rate, and barostatic reflexes were studied in cats. When the end-expired isoflurane concentration did not exceed 1.0 per cent tachycardia was observed which was abolished when the anaesthetic concentration was increased to 1.8 per cent. Arterial pressure, sympathetic nervous activity and vagal activity declined progressively with increasing depth of anaesthesia, but the reduction of vagal activity at all levels of anaesthesia always significantly exceeded the reduction of sympathetic activity. Barostatic reflexes, measured as the reduction in arterial pressure, pulse rate and sympathetic nervous activity when an aortic depressor nerve was stimulated electrically, were found to be normal, except that the response of arterial pressure was depressed at high isoflurane concentration.The authors therefore conclude that isoflurane depresses the cardiovascular system not only by direct action, but also by depression of the sympathetic nervous system. The tachycardia seen during isoflurane anaesthesia can be explained in part by a greater depression of parasympathetic than of sympathetic tone. The fact that barostatic reflexes were active during isoflurane anaesthesia while the reflex response of arterial pressure was diminished leads the authors to believe that isoflurane depresses the response of vascular smooth muscle to sympathetic impulses.

El-Naggar, Moustafa; Suerte, Eleuerto; Rosenthal, E.

doi: 10.1007/bf03005108pmid: 871938

SummaryRecent advances in pharmacology, physiology, and biochemistry have revealed the pathophysiologic derangements encountered in pheochromocytoma, and the rational foundations for its management; this is illustrated in reports of two cases.For pre-operative preparation we use phenoxybenzamine to block the alpha adrenergic receptors, as it allows improvement in the cardiovascular status, expansion of the blood volume, decrease in the basal metabolic rate and plasma free fatty acids and protection against adrenergic crisis. We use propranolol pre-operatively subsequent to effective alpha adrenergic receptor blockade only to control serious dysrhythmia, angina or myocardial ischaemia. The alpha and beta blocking agents are withheld 12 hours prior to operation.Preanaesthesic medication includes morphine, diazepam and scopolamine and induction and subsequent maintenance of anaesthesia are achieved with diazepam, fentanyl, pancuronium, nitrous oxide and oxygen. Lidocaine (50-100 mg) is administered prophylactically before induction of anaesthesia, tracheal intubation and concomitant with exaggerated pressor responses to surgical manipulations. These latter reactions are managed by phentolamine ( 1-5 mg ) until the first manifestation of tachyphylaxis; at this juncture we resort to a drip of sodium nitroprusside ( 50-100 ζ/minute).Successful management of pheochromocytoma demands anticipation of potential problems, prior preparation of necessary medication, adequate monitoring and close post-operative observation.

Busque, Lionel

doi: 10.1007/bf03005111pmid: 871941

SummaryAlveolar proteinosis is a rare disease characterized by the accumulation of a proteinoseous material inside the alveolus. Various forms of treatment have been tried without much success. Pulmonary lavage has been found effective in bringing relief to patients as well as objective amelioration. This presentation describes the technique used and the problems encountered.

Gale, CD.; Sanders, D. E.

doi: 10.1007/bf03005115pmid: 871945

SummaryA preliminary assessment of the effectiveness of the Bartlett-Edwards incentive spirometer was made using it as part of the post-operative treatment of 34 patients after open-heart surgery. Its effects on atelectasis were assessed by measuring vital capacity, arterial oxygen tensions, clinical signs and radiological changes. It was found that vital capacity fell after surgery to 41.5 per cent of the pre-operative level, but this rose after the use of the incentive spirometer by an average of 15.5 per cent. Arterial oxygen tensions were unaltered by the use of the incentive spirometer. Temperature, pulse and respirations were of little help in the early diagnosis of atelectasis, but all patients who were still pyrexic four days after operation showed radiological evidence of atelectasis. The incidence of atelectasis demonstrated radiologically was total 84 per cent and plate 69 per cent, subsegmental 34 per cent and segmental 9 per cent.The implications of these findings are discussed.

Keszler, H.; Bessette, M.; McBurney, R.; Davies, Glanville

doi: 10.1007/bf03005116pmid: N/A