Practice of Low Flow Anaesthesia and Volatile Agents Choices among Anaesthesia Providers at Muhimbili National Hospital and Muhimbili Orthopaedic Institute

Abstract

Background; Anaesthesia providers worldwide are practicing low flow anaesthesia due to the availability of modern workstations and heightened awareness on the environmental effects of waste anaesthesia gases. The routine practice of low flow Anaesthesia offers several advantages, including preservation of heat and humidity, reduced expenses of inhalational agents and reduction of theatre and environment pollution. Well-equipped Workstation and Stringent monitoring with Capnography, Oxygen and Agent analysers are mandatory for safe conduct of low flow anaesthesia. In most developing countries Low Flow Anaesthesia is still underutilized due to lack of monitoring equipments and sufficient knowledge on Low Flow Anaesthesia. Tanzania appears to have a paucity of studies on the prevailing practice pattern of fresh gas flow and volatile agents choices. Objective; The study aimed at assessing the practice of low flow anaesthesia and volatile agents choices among anaesthesia providers at Muhimbili national hospital and Muhimbili orthopaedic institute. Methodology; The study was a hospital based descriptive cross sectional study that was conducted at Muhimbili National Hospital and Muhimbili orthopaedic institute, involving 158 anaesthesia providers working in all operating theatre from July 2019 to February 2020. Approval for the study was granted by Muhimbili University of Health and Allied Sciences ethical committee. A Validated Structured questionnaire and checklist was used to collect information from anaesthesia providers and monitors availability. Data obtained included demographic, practice setting of Low flow anaesthesia, Availability of workstations, scavenging systems, monitoring equipments, breathing systems, Volatile agents routinely used and preferred Agent. Data were analysed using the IBM Statistical package for social science‘s version 23.0 and Using Pearson's Chi-square test and Fisher's exact test for some of categorical data. P value < 0.05 was considered statically significant. Results; in this study there were 158 Anaesthesia providers working in different operating room and intensive care according to duty schedule. The Prevailing practice pattern was high flow anaesthesia. Routine practice of Low flow anaesthesia was 27.2%, however, only 6% used fresh gas flow of 1l/min – 500mls/min complying with the actual meaning of low flow anaesthesia. Anaesthesia providers with > 10 years of experience and from Muhimbili National Hospital had the highest proportion of practice of low flow anaesthesia. There was a paucity of monitoring equipments and some were nonfunctional. All anaesthesia providers had workstations and only 2.3% displayed Minimum Alveolar concentration (MAC) values, 79.1% respondents worked in theatre rooms with functioning scavenging systems, 55.8% used capnography, 6.9% monitored inspiratory Oxygen and none of anaesthesia providers used Bispectral and Agent Analyzers. Isoflurane was the most routinely used inhalational agents (100%) followed by Sevoflurane (69%), then Halothane (32%). Sevoflurane was the most preferred (55.7%), followed by Isoflurane (42.4%), Halothane (1.9%). Desflurane was not available in these hospitals. Conclusion; Low flow anaesthesia is seldom practiced despite having strong evidence of attractive advantages in medical practice and ergonomics. Availability of Sophisticated workstation and recommended monitoring equipments for volatile agents and other anaesthesia gas is still a problem within the studied hospitals. Isoflurane is the routinely used volatile anaesthetics; sevoflurane availability is restricted, however a most preferred inhalational Agent. Currently Halothane is occasionally used at Muhimbili hospital and desflurane still not available in all hospitals involved in this study. Recommendations; Low flow anaesthesia basic principles and technical preconditions should be well taught to all anaesthesia providers. Intensify LFA training during residency and nurse anaesthesia training, Initiate protocols/ codes for LFA and start to implement it in our area. Improve availability of respiratory gas monitors and update our anaesthesia Machines. Further study need to be done on cost analysis of inhalational agent use and knowledge assessment on LFA.