Is fasting prior to procedural sedation necessary?
In JAMA pediatrics this month is a new article from Bhatt et al evaluating the need for fasting prior to procedural sedation in pediatric patients.
Traditionally, as there has been inadequate data in the past, The ASA (American Society of Anesthesiologist) guidelines recommend that patients undergoing PSA for "elective procedures" fast according to the standards used for general anesthesia.
This traditionally requires that patients not eat or drink for two hours after drinking clear liquids and six hours after ingesting solid foods or cow's milk.
This study was meant to provide a sufficient sample size in order to create meaningful data to guide practice.
Design
Multi center prospective cohort study of children aged 0 to 18 years who received procedural sedation for a painful procedure in 6 Canadian pediatric EDs from July 2010 to February 2015.
Primary risk factor: pre-procedural fasting duration; also looked at age, sex, ASA classification, preprocedural and sedation medications, procedure type.
Population: 6183 children with a median age of 8.0 years of whom 6166 (99.7%) had healthy or mild systemic disease (American Society of Anesthesiologists levels I or II)
This study looked at four outcomes:
1. Pulmonary Aspiration
2. Occurrence of any adverse event
3. Serious adverse events
4. Vomiting
Results
There were zero aspirations.
"Our study findings provide support to the idea that strict adherence to ASA fasting guidelines does not improve patient outcomes for children undergoing procedural sedation in the ED."
There were 717 adverse events of which 68 were serious adverse events and 315 (5.1%;95%CI,4.6%-5.7%) were vomiting (on 6 patients had vomiting during actual sedation; others were post-procedure).
The odds ratio of occurrence of any adverse event, serious adverse events, and vomiting did not change significantly with each additional hour of fasting duration for both solids (any adverse event: OR, 1.00; 95% CI, 0.98 to 1.02;serious adverse events, OR, 1.01; 95% CI, 0.95-1.07; vomiting: OR, 1.00;95% CI, 0.97-1.03) and liquids (any adverse event: OR, 1.00; 95% CI, 0.98-1.02; serious adverse events: 1.01, 95% CI, 0.95-1.07; vomiting: OR, 1.00; 95% CI, 0.96-1.03).
Limitations/Discussion/Notes
In general it appears that fasting prior to procedural sedation in unnecessary in this pediatric population.
Only 112 patients consumed solids within 2 hours of sedation; conclusions limited for short period of fasting.
Previous studies show pH is equivalent in study 2 hours after ingestion compared to fasting.
As a note: 62.2% of patients received ketamine which may have reflex protective properties.
Difficult to compare aspiration rates when zero aspirations were reported. However, given that there are no reports in ED literature of aspiration from procedural sedation and the fact that rates are so low in general, it seems that the benefit of earlier sedation rather than overutilization of ED resources to keep a patient in the ED may be beneficial for patient safety.
This study does not apply to general anesthesia, however this is generally an emergent procedure in the ED.
Sources:
Bhatt et al
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