Diphenhydramine as an adjunct to sedation for colonoscopy: a double-blind randomized, placebo-controlled study.

BACKGROUND: Intravenous benzodiazepines in combination with opiates are used to achieve moderate sedation for colonoscopy. Although effective, these agents have potential adverse effects, such as respiratory depression and hypotension. Diphenhydramine hydrochloride possesses central nervous system depressant effects that theoretically could provide a synergistic effect for sedating patients. OBJECTIVE: The objective was to assess the efficacy of adding diphenhydramine hydrochloride as an adjunct to improve sedation and to reduce the amount of standard sedatives used during colonoscopy. DESIGN: We conducted a prospective, randomized, double-blind, placebo-controlled study. SETTING: The study was conducted in a university hospital with an active GI fellowship training program. PATIENTS: The study group comprised 270 patients undergoing screening/diagnostic/therapeutic colonoscopy were enrolled. INTERVENTIONS: Patients were randomized to receive either 50 mg of diphenhydramine or placebo, given intravenously 3 minutes before starting conscious sedation with intravenous midazolam and meperidine. MAIN OUTCOME MEASUREMENTS: The main outcome measure was anesthetic effect as assessed by the endoscopy team and by the patient; quantity of adjunctive sedatives to achieve adequate sedation. RESULTS: Of 270 patients, data were analyzed for 258 patients, with 130 patients in the diphenhydramine group and 128 patients in the placebo group. There was a 10.1% reduction in meperidine usage and 13.7% reduction in midazolam usage in favor of the diphenhydramine group. The mean evaluation scores as judged by the faculty, the fellows, and the nurses were statistically significant in favor of the diphenhydramine group. In addition, patient scores for overall sedation and pain level favored the group that received diphenhydramine. CONCLUSIONS: Intravenous diphenhydramine given before initiation of standard sedation offers a significant benefit to conscious sedation for patients undergoing colonoscopy.

Human exposure to the jet fuel, JP-8.

INTRODUCTION: This study investigates anecdotal reports that have suggested adverse health effects associated with acute or chronic exposure to jet fuel. METHODS: JP-8 exposure during the course of the study day was estimated using breath analysis. Health effects associated with exposure were measured using a neurocognitive testing battery and liver and kidney function tests. RESULTS: Breath analysis provided an estimate of an individual's recent JP-8 exposure that had occurred via inhalation and dermal routes. All individuals studied on base exhaled aromatic and aliphatic hydrocarbons that are found in JP-8. The subject who showed evidence of the most exposure to JP-8 had a breath concentration of 11.5 mg x m(-3) for total JP-8. This breath concentration suggested that exposure to JP-8 at an Air Guard Base is much less than exposure observed at other Air Force Bases. This reduction in exposure to JP-8 is attributed to the safety practices and standard operating procedures carried out by base personnel. The base personnel who exhibited the highest exposures to JP-8 were fuel cell workers, fuel specialists and smokers, who smoked downwind from the flightline. DISCUSSION: Although study-day exposures appear to be much less than current guidelines, chronic exposure at these low levels appeared to affect neurocognitive functioning. JP-8-exposed individuals performed significantly poorer than a sample of non-exposed age- and education-matched individuals on 20 of 47 measures of information processing and other cognitive functions.