The effect of obesity on the ED(95) of propofol for loss of consciousness in children and adolescents.

INTRODUCTION: Anesthesiologists face a dilemma in determining appropriate dosing of anesthetic drugs in obese children. In this study we determined the dose of propofol that caused loss of consciousness in 95% (ED(95)) of obese and nonobese children as determined by loss of eye lash reflex. METHODS: Forty obese (body mass index [BMI] > 95th percentile for age and gender) and 40 normal weight (BMI 25th to 84th percentile) healthy ASA 1 to 2 children ages 3 to 17 years presenting for surgical procedures were studied using a biased coin design. The primary endpoint was loss of lash reflex at 20 seconds after propofol administration. The first patient in each group received 1.0 mg/kg of IV propofol, and subsequent patients received predetermined propofol doses based on the lash reflex response in the previous patient. If the lash reflex was present, the next patient received a dose increment of 0.25 mg/kg. If the lash reflex was absent, the next patient was randomized to receive either the same dose (95% probability) or a dose decrement of 0.25 mg/kg (5% probability). The ED(95) and 95% confidence intervals (CI) were calculated using isotonic regression and bootstrapping methods respectively. RESULTS: The ED(95) of propofol for loss of lash reflex was significantly lower in obese pediatric patients (2.0 mg/kg, approximate 95% CI, 1.8 to 2.2 mg/kg) in comparison with nonobese patients (3.2 mg/kg, approximate 95% CI, 2.7 to 3.2 mg/kg), P ≤ 0.05. DISCUSSION: A simple approach to deciding what dose of propofol should be used for induction of anesthesia in children ages 3 to 17 years is to first establish the child's BMI on readily available gender-specific charts. Obese children (BMI >95th percentile for age and gender) require a lower weight-based dose of propofol for induction of anesthesia, than do normal-weight children.

Safety and effectiveness of ketamine as a sedative agent for pediatric GI endoscopy.

BACKGROUND: The ideal sedation for children undergoing GI endoscopy remains elusive. After ketamine was introduced as a sedative agent in our GI procedure suite, improved sedation and reduced complications were observed. The aim of this study was to assess the safety and effectiveness of ketamine as a sedative agent for GI endoscopy in pediatric patients. METHODS: A retrospective cohort study of 402 procedures (EGD, colonoscopy) was performed. Sedation-related complications were defined as hypoxia (oxygen saturation <95% by pulse oximetry), agitation, emergence reactions, stridor, laryngospasm, nausea, vomiting, aspiration, and muscle twitching, or any combination thereof. Sedation groups were defined as the following: Group I, midazolam and meperidine (n=192); Group II, midazolam, meperidine, and ketamine (n=82); and Group III, midazolam and ketamine (n=128). RESULTS: Group 1 (midazolam and meperidine) had the highest frequency of complications, most commonly hypoxia. Group 3 (midazolam and ketamine) had the lowest rate of complications (p=0.001) and the highest rate of adequate sedation, although the difference was not significant (p=0.07). CONCLUSIONS: The combination of midazolam and ketamine appears to provide safe and effective sedation for pediatric patients undergoing endoscopy.