Evaluation and control of waste anesthetic gases in the postanesthesia care unit.

BACKGROUND: Few studies have addressed waste anesthetic gases (WAGs) in the postanesthesia care unit (PACU) related to exhaled sevoflurane and nitrous oxide. PURPOSE: To evaluate the effectiveness of a new scavenging system to control WAGs in the PACU. DESIGN: Comparative and descriptive study. METHODS: This pilot study compared exposure to WAGs with and without a scavenging system using infrared technology to visualize and quantify exposure to these gases in the PACU. FINDING: The results showed a significant reduction (P < .05) in both nitrous oxide and sevoflurane at both six inches and three feet from the patient's breathing zone, as well as in the work area of the perianesthesia nurses in the PACU. CONCLUSIONS: WAG exposure may be more easily managed through the use of this new scavenging system to better control occupational exposures to these gases among PACU personnel.

Evaluation of two nitrous oxide scavenging systems using infrared thermography to visualize and control emissions.

BACKGROUND: The authors conducted a study to determine the effectiveness of two waste anesthetic gas-scavenging systems. They also evaluated one of the systems to determine the effect of work practices in controlling waste nitrous oxide (N2O). METHODS: The authors collected a minimum of 13 data sets in each phase of the study that included infrared thermography, digital videography and real-time air analysis for ambient concentrations of waste N2O. Surgeon 1, who had experience using both systems, used the Safe Sedate Dental Mask (Airgas, Radnor, Pa.) system (system I) in phase I and the Porter Nitrous Oxide Sedation System (Porter Instruments, Hatfield, Pa.) (system II) in phase II. Surgeon 2, who did not have experience using system I, used it in phase III. To evaluate each system's effectiveness, the authors collected N2O air concentration data from phases I and II and compared the data with the National Institute for Occupational Safety and Health Recommended Exposure Limit (NIOSH REL). They also compared phases I and III to determine the effect of work practices on the systems' effectiveness. RESULTS: Surgeon 1 controlled occupational exposure to N2O significantly better using system I than using system II. Mean N2O air concentration levels during phases I and II were 61.6 parts per million (ppm) and 225.6 ppm, respectively. Surgeon 2 did not achieve results comparable to those of surgeon 1 in phase I using system I. Infrared thermography and air concentration data suggested that key work practices and patient and surgical variables accounted for the different results obtained in phases I and III. CONCLUSIONS: Although neither system was able to control occupational exposure of N2O oxide below the NIOSH REL, system I met the American Conference of Governmental Industrial Hygienists threshold limit value of less than 50 ppm during an eight-hour day and performed significantly better than did system II. CLINICAL IMPLICATIONS: System I achieved maximal efficiency when combined with consistent best work practices.

Treatment of painful temporomandibular joint dysfunction with the sagittal split ramus osteotomy.

PURPOSE: We describe a new indication for the sagittal split ramus osteotomy with rigid fixation to treat patients with painful dysfunction of the temporomandibular joint. PATIENTS AND METHODS: Ten patients for whom nonsurgical management failed were found to have a mandibular condyle positioned postero-superior within the glenoid fossa with reduced joint space on corrected-axis tomograms. The sagittal split ramus osteotomy was used to reposition the proximal segment and to increase joint space. Preoperative and long-term postoperative (average, 44.7 months) symptoms and tomographic findings were retrospectively compared. RESULTS: Significant pain relief occurred postoperatively in all patients. One patient had a relapse after initial improvement. No patient developed a malocclusion. The long-term radiographic condyle-fossa relationship tended to return to its preoperative position with no relapse of clinical symptoms, except in the 1 patient. CONCLUSION: The sagittal split ramus osteotomy with rigid fixation is another procedure that can be used to treat painful temporomandibular joint dysfunction by changing the position of the mandibular condyle in the glenoid fossa.