Violating traditional NPO guidelines with PO contrast before sedation for computed tomography

Assessing Residual Gastric Fluid Volume after Administering Diluted Oral Contrast until One Hour Prior to Anesthesia in Children: An Observational Cohort Study

Background: Gastric fluid volume has been used as a surrogate marker for pulmonary aspiration risk in studies evaluating fasting protocol safety. This study measured residual gastric fluid volume in children using a protocol in which diluted oral contrast medium was administered up until one hour before anesthesia. Methods: This was a single-center prospective observational cohort trial of 70 children for elective abdominal/pelvic computed tomography (CT). Imaging was performed after diluted enteral contrast medium administration, beginning two hours before and ending at least one hour before induction. For each patient, gastric fluid volume was calculated using an image region of interest. The primary outcome measure was gastric fluid volume measured using the computed tomography image. Results: The median time from the end of contrast administration to imaging was 1.5 h (range: 1.1 to 2.2 h). Residual gastric volume, measured using CT was <0.4 mL/Kg in 33%; ≥0.4 mL/Kg in 67%; and ≥1.5 mL/Kg in 44% of patients. Residual gastric volumes measured using CT and aspiration were moderately correlated (Spearman's correlation coefficient = 0.41, p = 0.0003). However, the median residual gastric volume measured using CT (1.17, IQR: 0.22 to 2.38 mL/Kg) was higher than that of aspiration (0.51, IQR: 0 to 1.58 mL/Kg, p = 0.0008 on differences in paired measures). Three cases of vomiting were reported. No evidence of pulmonary aspiration was identified. Conclusions: Children who receive large quantities of clear fluid up to one hour before anesthesia can have a significant gastric residual volume.

An international multidisciplinary consensus statement on fasting before procedural sedation in adults and children

The multidisciplinary International Committee for the Advancement of Procedural Sedation presents the first fasting and aspiration prevention recommendations specific to procedural sedation, based on an extensive review of the literature. These were developed using Delphi methodology and assessment of the robustness of the available evidence. The literature evidence is clear that fasting, as currently practiced, often substantially exceeds recommended time thresholds and has known adverse consequences, for example, irritability, dehydration and hypoglycaemia. Fasting does not guarantee an empty stomach, and there is no observed association between aspiration and compliance with common fasting guidelines. The probability of clinically important aspiration during procedural sedation is negligible. In the post-1984 literature there are no published reports of aspiration-associated mortality in children, no reports of death in healthy adults (ASA physical status 1 or 2) and just nine reported deaths in adults of ASA physical status 3 or above. Current concerns about aspiration are out of proportion to the actual risk. Given the lower observed frequency of aspiration and mortality than during general anaesthesia, and the theoretical basis for assuming a lesser risk, fasting strategies in procedural sedation can reasonably be less restrictive. We present a consensus-derived algorithm in which each patient is first risk-stratified during their pre-sedation assessment, using evidence-based factors relating to patient characteristics, comorbidities, the nature of the procedure and the nature of the anticipated sedation technique. Graded fasting precautions for liquids and solids are then recommended for elective procedures based upon this categorisation of negligible, mild or moderate aspiration risk. This consensus statement can serve as a resource to practitioners and policymakers who perform and oversee procedural sedation in patients of all ages, worldwide.

The risk of shorter fasting time for pediatric deep sedation

BACKGROUND

Current guidelines adopted by the American Academy of Pediatrics calls for prolonged fasting times before performing pediatric procedural sedation and analgesia (PSA). PSA is increasingly provided to children outside of the operating theater by sedation trained pediatric providers and does not require airway manipulation. We investigated the safety of a shorter fasting time compared to a longer and guideline compliant fasting time. We tried to identify the association between fasting time and sedation-related complications.

METHODS

This is a prospective observational study that included children 2 months to 18 years of age and had an American Society of Anesthesiologists physical status classification of I or II, who underwent deep sedation for elective procedures, performed by pediatric critical care providers. Procedures included radiologic imaging studies, electroencephalograms, auditory brainstem response, echocardiograms, Botox injections, and other minor surgical procedures. Subjects were divided into two groups depending on the length of their fasting time (4-6 h and >6 h). Complication rates were calculated and compared between the three groups.

RESULTS

In the studied group of 2487 subjects, 1007 (40.5%) had fasting time of 4-6 h and the remaining 1480 (59.5%) subjects had fasted for >6 h. There were no statistically significant differences in any of the studied complications between the two groups.

CONCLUSIONS

This study found no difference in complication rate in regard to the fasting time among our subjects cohort, which included only healthy children receiving elective procedures performed by sedation trained pediatric critical care providers. This suggests that using shorter fasting time may be safe for procedures performed outside of the operating theater that does not involve high-risk patients or airway manipulation.

Ketamine Sedation After Administration of Oral Contrast: A Retrospective Cohort Study

BACKGROUND

The American Academy of Pediatrics and American Society of Anesthesiologists have published consensus-based fasting guidelines intended to reduce the risk of pulmonary aspiration. The purpose of our study was to compare the rate of adverse events in patients sedated with ketamine within 2 hours of oral contrast intake to those who were nil per os (NPO).

METHODS

A retrospective cohort review of a database of children between July 2008 and May 2011. The rate of adverse events in children sedated with ketamine after intake of oral contrast for an abdominal computed tomography were compared with those sedated without taking oral contrast.

RESULTS

One hundred and four patients sedated for a computed tomography scan; 22 patients were sedated within 2 hours of taking oral contrast, and 82 were NPO. The 2 groups were comparable with regard to gender, race, and American Society of Anesthesiologists status. The mean (SD) time between the second dose of oral contrast and induction of sedation was 58 (24) minutes. Vomiting occurred in 4 of 22 patients in the oral contrast group (18%; 95% confidence interval 2%-34%) and 1 of 82 patients in the NPO group (1%; 95% confidence interval, 0%, 4%; P < .001). There was no difference in oxygen desaturation between the groups (P = .6).

CONCLUSIONS

Children who received oral contrast up to 58 minutes before ketamine sedation had a higher rate of vomiting than those who did not receive oral contrast. We did not identify cases of clinical aspiration, and the incidence of hypoxia between the 2 groups was not statistically significant.

Pediatric critical care physician-administered procedural sedation using propofol: a report from the Pediatric Sedation Research Consortium Database

OBJECTIVE

Increasing demand for pediatric procedural sedation has resulted in a marked increase in provision of pediatric procedural sedation by pediatric critical care physicians both inside and outside of the ICU. Reported experience of pediatric critical care physicians-administered pediatric procedural sedation is limited. We used the Pediatric Sedation Research Consortium database to evaluate a multicenter experience with propofol by pediatric critical care physicians in all settings.

SETTING

Review of national Pediatric Sedation Research Consortium database to identify pediatric procedural sedation provided by pediatric critical care physicians from 2007 to 2012. Demographic and clinical data were collected to describe pediatric procedural sedation selection, location, and delivery. Multivariable logistic regression analysis was performed to identify risk factors associated with pediatric procedural sedation-related adverse events and complications.

MEASUREMENTS AND MAIN RESULTS

A total of 91,189 pediatric procedural sedation performed by pediatric critical care physicians using propofol were included in the database. Median age was 60.0 months (range, 0-264 months; interquartile range, 34.0-132.0); 81.9% of patients were American Society of Anesthesiologists class I or II. Most sedations were performed in dedicated sedation or radiology units (80.9%). Procedures were successfully completed in 99.9% of patients. A propofol bolus alone was used in 52.8%, and 41.7% received bolus plus continuous infusion. Commonly used adjunctive medications were lidocaine (35.3%), opioids (23.3%), and benzodiazepines (16.4%). Overall adverse event incidence was 5.0% (95% CI, 4.9-5.2%), which included airway obstruction (1.6%), desaturation (1.5%), coughing (1.0%), and emergent airway intervention (0.7%). No deaths occurred; a single cardiac arrest was reported in a 13-month-old child receiving propofol and ketamine, with no untoward neurologic sequelae. Risk factors associated with adverse event included: location of sedation, number of adjunctive medications, upper and lower respiratory diagnosis, prematurity diagnosis, weight, American Society of Anesthesiologists status, and painful procedure.

CONCLUSIONS

Pediatric procedural sedation using propofol can be provided by pediatric critical care physicians effectively and with a low incidence of adverse events.