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We read with interest the article by Gunathilaka, et al. [1]
reporting on comparison of propofol and fentanyl for
sedation in pediatric bronchoscopy. We wish to raise the
following issues related to the article:
(i) The
authors state that the allocated assignment was not
disclosed to the bronchoscopist and the patient. However,
the independent observer who also decided the cough score,
secretion score and physician satisfaction score was not
blinded to the assignment and this could have caused
assessment bias in the study. Additionally, the primary
investigator was not blinded to the study arm. However, the
stop watch reading to document the time of achievement of
Ramsay score 3 (primary outcome) was done by the primary
investigator himself, which may have increased the chances
of assessment bias in the study. It would have been better
that a third person not involved in the study and blinded to
the intervention was given the responsibility of assessing
primary outcome (time to achieve Ramsay score 3).
(ii) The baseline characteristics table shows that mean (SD)
oxygen saturation was 99.1 (1.5) and 99.1 (1.4) in propofol
and fentanyl groups, respectively. This implies that upper
limit of oxygen saturation was more than 100% in both the
groups, which is not possible.
(iii) The results
show that the mean (SD) time to achieve Ramsay score 3
(primary outcome) was 15.7 (4.4) seconds in propofol group.
However, in secondary outcomes, the additional midazolam
doses needed in propofol group was 11. But midazolam could
only be used if the child was not sedated within 180
seconds. So the use of midazolam needs more clarification.
(iv) The article mentions that intravenous midazolam was
repeated every 1 minute if Ramsay score of 3 was not
achieved. The onset of effect for midazolam is 1 to 2.5
minutes, the peak effect is at 3 to 4 minutes, and the
duration of effect is 15 to 80 minutes [2]. In a
meta-analysis done for the comparison of propofol and
midazolam for bronchoscopy [3], in all the four included
randomized controlled trials, midazolam was given every ³2
minutes if sedation goal was not achieved [3].
(v) If
midazolam was being used for sedation as mentioned above,
then it is difficult to rely on the results because the time
to achieve sedation and recovery would have also been
affected by midazo-lam. Applying a regression analysis in
the outcome variables would have been more justified [4].
Funding: None; Competing interests: None stated.
References
1. Gunathilaka PK,
Jat KR, Sankar J, Lodha R, Kabra SK. Propofol versus
fentanyl for sedation in pediatric bronchoscopy: A
randomized controlled trial. Indian Pediatr. 2019;56:1011-6.
2. Horn E, Nesbit SA. Pharmacology and pharmacokinetics
of sedatives and analgesics. Gastrointest Endosc Clin N Am.
2004;14:247-68.
3. Wang Z, Hu Z, Dai T. The
comparison of propofol and midazolam for bronchoscopy: A
meta-analysis of randomized controlled studies. Medicine
(Baltimore). 2018;97:e12229.
4. Schneider A, Hommel
G, Blettner M. Linear regression analysis: Part 14 of a
series on evaluation of scientific publications. Deutsches
Ärzteblatt International. 2010;107:776.
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