การออกแบบอุปกรณ์ต้นแบบระบบระบายอากาศเฉพาะที่เพื่อลดปริมาณยาดมสลบในห้องผ่าตัด

Abstract

The anesthetist personnel in pediatric surgical room are exposed the high levels of both Nitrous oxide and Sevoflurane even the scavenging system was functioning, the standardized work instructions, appropriated anesthesia circuit, air circulation and ventilation system was improved. The waste anesthesia agents (WAGs) were not exceed the standard in surgical room were higher than 5 times the occupational exposure limits (OELS). Therefore, a pilot model of the local exhaust ventilation (LEV) system in operation room was developed. This study aimed to describe the WAGS concentrations in the operation room and recovery room. The LEV system for decrease the levels of WAGS were developed and theirs performance were test. The WAGs in the 5 operation rooms and 1 recovery room were measured by the gas direct reader (Gasmet DX-4303) along the working hours. The 8hr-time weight average were calculated and presented in this study. The LEV system including hood, piping, and suction fan. The capture velocity was met the ACGIH criteria 1 meter/second (m/s) and measured by anemometer air velocity (Velocical, TSI, Germany) during July 2014 - October 2016. The WAGs measured in 8hr-time weight average were not exceed the standard but in the neurological surgical room were higher than 5 times the OELs because patients' position. The first design there were 2 types of LEVS included canister vacuum fan and vacuum system were designed as the main power of LEVS system. The capture and face velocity of LEV model 1 were calculated and set 0.010 and 0.211 meter/second (m/s), respectively and and the capture and face velocity of LEV model 2 were calculated and set at 1 and 18.5 meter/second (m/s), respectively However, the measured by anemometer air velocity the capture velocities at 25 centimeters (cm.) away from LEVs were 0.15±0.03 meter/second (m/s) while the face velocities of LEV model 1 was 0.19±0.04 meter/second (m/s) and the face velocities of LEV model 2 was 4.42+0.38 meter/second (m/s). The measured of face velocities less than the face velocities from calculated. The noise level of the LEV model I was 85.73 dBA and the noise level of the LEV model 2 was 94.62 dBA A pilot model of LEV system was practical and useful but it was too noisy.