To the Editor:

I read with interest the report by Beach et al.1  on the relationship between nil per os (NPO) time and major adverse events, with special attention to pulmonary aspiration. The authors conclude that NPO status is not an independent predictor of major complications.

As reported in other studies,2,3  the incidence of pulmonary aspiration was found to be quite low, with only 10 cases out of over 139,000 pediatric sedations collected between 2007 and 2011. It is noteworthy that NPO definitions within the Pediatric Sedation Research Consortium database (solids, 8 h; nonclear fluids, 6 h; and clears, 2 h) are out of step with the most recent American Society of Anesthesiologists guidelines from 2011,4  which recommend 6 h for formula/milk and “light” solids, 4 h for breast milk, and 2 h for clear liquids. Many Anesthesiology departments, including ours at Vanderbilt University, Nashville, Tennessee, have moved all solids to a fasting time of 6 h. By this measure, all of the 10 cases of aspiration would have been NPO appropriate with no episodes in those not NPO.

A look at Emergency Medicine literature5,6  shows a low incidence of aspiration even in nonfasted patients, many of whom are likely to be in pain. The American College of Emergency Physicians published a clinical policy in 20147  recommending that procedural sedation in the Emergency Room not be delayed solely due to NPO time. Unfortunately, the data presented in the study by Beach et al. are not broken down into elective versus emergent procedures. Additionally, the type of provider (emergency physician vs. other) cannot be used as a surrogate marker as emergency physicians often provide elective sedation services outside of the Emergency Room.

So where does this leave us? We are not suggesting, based on current evidence, that we reduce the NPO times for elective general anesthesia cases with planned airway instrumentation. But perhaps we should rethink the questions that we need answered regarding NPO in pediatric sedation.

What about emergent procedures without planned airway instrumentation? Many in emergency medicine would counter this question has already been answered. Can we quantify the risk of aspiration with planned airway instrumentation versus unplanned versus none at all? Does ketamine or dexmedetomidine, which preserve respiratory drive and airway tone better than propofol, offer a safer alternative in the nonfasted patient? All of these questions will be difficult to answer given the very low incidence of aspiration but we should certainly try.

Competing Interests

The author declares no competing interests.

References

1.
Beach
ML
,
Cohen
DM
,
Gallagher
SM
,
Cravero
JP
:
Major adverse events and relationship to nil per os status in pediatric sedation/anesthesia outside the operating room: A report of the Pediatric Sedation Research Consortium.
Anesthesiology
2016
;
124
:
80
8
2.
Walker
RW
:
Pulmonary aspiration in pediatric anesthetic practice in the UK: A prospective survey of specialist pediatric centers over a one-year period.
Paediatr Anaesth
2013
;
23
:
702
11
3.
Kluger
MT
,
Short
TG
:
Aspiration during anaesthesia: A review of 133 cases from the Australian Anaesthetic Incident Monitoring Study (AIMS).
Anaesthesia
1999
;
54
:
19
26
4.
American Society of Anesthesiologists Committee
:
Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: Application to healthy patients undergoing elective procedures: An updated report by the American Society of Anesthesiologists Committee on Standards and Practice Parameters.
Anesthesiology
2011
;
114
:
495
511
5.
Agrawal
D
,
Manzi
SF
,
Gupta
R
,
Krauss
B
:
Preprocedural fasting state and adverse events in children undergoing procedural sedation and analgesia in a pediatric emergency department.
Ann Emerg Med
2003
;
42
:
636
46
6.
Roback
MG
,
Bajaj
L
,
Wathen
JE
,
Bothner
J
:
Preprocedural fasting and adverse events in procedural sedation and analgesia in a pediatric emergency department: Are they related?
Ann Emerg Med
2004
;
44
:
454
9
7.
Godwin
SA
,
Burton
JH
,
Gerardo
CJ
,
Hatten
BW
,
Mace
SE
,
Silvers
SM
,
Fesmire
FM
;
American College of Emergency Physicians
:
Clinical policy: Procedural sedation and analgesia in the emergency department.
Ann Emerg Med
2014
;
63
:
247
58.e18