Nitrous Oxide May Aggravate Postanesthetic Conditions in Mentally Retarded Patients

Objectives: It is difficult to directly interview mentally retarded patients about systemic conditions after ambulatory general anesthesia. Since their parents or caretakers are continuously observe and care them after they return their home, these persons may be alternative information providers. The objective of this study was to analyze the anesthesia factors influencing on postanesthetic systemic conditions informed by the parents or caretakers after dental treatments of mentally retarded patients under ambulatory general anesthesia. Methods: After approval from the institutional review board, the medical records of the mentally retarded patients undergoing dental treatments in Tokyo Dental College Suidoubashi Hospital from 2003 to 2006 were reviewed to investigate patient profiles, anesthetic management and postoperative complications. Exclusion criteria were as follows: an administration of an opioid analgesic and/or neostigmine, tooth extraction, and gastroesophageal reflux disease. Parents or caretakers were asked to reply a postanesthetic questionnaire about systemic conditions of their children on the operative and the following days. The question items include fatigue, complexion, nausea and appetite. The questionnaire was submitted by the parents at the outpatient on the following day and summarized for this study. Multivariate logistic regression analysis was used in this study. Independent variables included gender, age, type of disability, operation time, anesthesia time, time between extubation and drinking water or discharge and type of anesthetic agents. Results: Multivariate logistic regression analysis suggests that nitrous oxide may influence on postoperative systemic conditions including fatigue, complexion, nausea and appetite. Conclusion: These results suggest that nitrous oxide may aggravate postanesthetic systemic conditions in mentally retarded patients undergoing ambulatory general anesthesia.