Although 2D-US has shown higher first success rate, less needle
passes and fastest cannulation in comparison to landmarks,
60% of the
responders used it only occasionally and mostly as a rescue technique.
Despite important limitations in our survey (ie, data collected in
2014, low response rate), we concluded that:
1. Pediatric arterial cannulation seemed to be mostly based on per-
sonal preference rather than new evidence.
2. The use of 2D-US was limited, despite its superiority over land-
In conclusion, arterial line cannulation does not show a unifor-
mity of practice. Further studies may standardize the procedure (ie,
sterility, insertion techniques, site of cannulation, maintenance).
The study was approved by the IRB of the McGill University Health
Centre: Nr 13-451-PED.
Informed consent was obtained from participants upon starting
CONFLICT OF INTEREST
The authors report no conflict of interest.
Department of Anesthesia, The Montreal Children’s Hospital, McGill
University, Montreal, QC, Canada
1. Glatz AC, Shah SS, McCarthy AL, et al. Prevalence of and risk factors
for acute occlusive arterial injury following pediatric cardiac catheteri-
zation: a large single-center cohort study. Catheter Cardiovasc Interv.
2. Kim EH, Lee JH, Song IK, et al. Posterior tibial artery as an alterna-
tive to the radial artery for arterial cannulation site in small
children: a randomized controlled study. Anesthesiology. 2017;127:
3. Varga EQ, Candiotti KA, Saltzman B, et al. Evaluation of distal radial
artery cross-sectional internal diameter in pediatric patients using
ultrasound. Pediatr Anesth. 2013;23:460-462.
4. Dumond AA, da Cruz E, Almodovar MC, Friesen RH. Femoral artery
catheterization in neonates and infants. Pediatr Crit Care Med.
5. Aouad-Maroun M, Raphael CK, Sayyid SK, Farah F, Akl EA. Ultra-
sound-guided arterial cannulation for paediatrics. Cochrane Database
Syst Rev 2016;(9):CD011364.
Investigating understanding in pediatric anesthesia informed
Sir—The study published by Gentry et al
in 2017 provides unique
insight into the content of informed consent conversations for pedi-
atric anesthesia care. In their paper, authors explored how the inclu-
sion of discrete elements of informed consent (eg, description of the
plan, risks, benefits), parental recall, and perceived understanding are
related. Findings demonstrated a significant association between
recall and understanding, but no significant association between the
inclusion of 3 informed consent elements and understanding. In
other words, the inclusion of more discrete elements of informed
consent did not correlate with enhanced parental understanding. In
their discussion, the authors indicated that the relatively small sam-
ple size could explain this lack of association.
We propose an additional explanation for the observed lack of
association between parental understanding and inclusion of discrete
elements of informed consent: Parents simply may not understand the
elements of informed consent as they are presented by care providers.
Thus, it may be the case that clinicians and investigators assume a
level of parental health literacy that in fact may not be present. An
alternative, nonmutually exclusive conclusion is that providers do not
effectively describe the elements of informed consent. Lastly, as
demonstrated by Tait et al,
parental reports of perceived understand-
ing tend to overestimate actual understanding. In any case, the most
reliable conclusion that can be drawn is that more robust methodology
for assessing parental understanding is warranted.
Prior work by Kodish et al
investigates parental understanding
of the term “randomization” as it pertains to childhood leukemia tri-
als. Authors analyzed audio-taped informed consent conversations
and assessed parental understanding based on answers to 2 specific