Depth of Anesthesia and Their Associated Factors; Prospective Cross sectional Study at Jimma University Medical Center Jimma, Ethiopia.

Abstract

Background: Nowadays assessing of depth of anesthesia is an important issue across the world, because if it is not assessed or monitored correctly, the consequence can affect both physical and psychosocial health, prolong the recovery time, increase morbidity, and impairs quality of life and increase medical costs. Adequate depth of anesthesia helps to avoid overdose of anesthesia drugs, prevent awareness under general anesthesia, decrease post-operative pain intensity and decrease the analgesic requirements, and also improves patient outcome. The mortality associated with depth of anesthesia monitored with BIS is lower compared to those not monitored. So to overcome such problem it’s recommended to use Bispectral index (BIS) monitor during general anesthesia to assess depth of anesthesia which is not available in low income countries including Ethiopia. Objective: The present study aimed to assess depth of anesthesia, and their associated factors among patients underwent surgery with general anesthesia at JMC. Methods: Prospective cross sectional study design was applied for four months (September 2021 to December 2021) among patients who underwent surgery with general anesthesia. All patients available during data collection who met inclusion criteria were enrolled in the study as they randomly scheduled for surgery. Data were collected by structured questionnaire. Depth of anesthesia was assessed by BIS intraoperatively. Accidental intraoperative awareness was assessed by Brice questionnaire by hiring the trained data collectors. Data were cleaned, entered in to epidata (version 4.6.1) and finally exported to SPSS (version 26) for analysis. The factors associated with the outcome variables were determined by cross tabulation and logistic regression analysis. The correlation of the variables was analyzed by Pearson correlation. P-value of <0.05 was considered as statistically significant. The finding of the study was expressed by applying statistical analysis (mean, standard deviation, percentage) and presented using tables, graphs, figures and narration. Results: A total of 100 patients who underwent elective major surgery were enrolled in the study with the mean age of 43+14.9 years that ranged from 18-80 years. Less than half of the patients (43%) had adequate anesthesia depth while the remaining 57% (CI 47.13-66.87%) of surgeries were performed with either light or deep anesthesia. Inadequate depth of anesthesia was affected by mean MAC of isoflurane (<1.117), sex (female), number of premedication (<2), type of current surgery (cholecystectomy) and IV induction agents (thiopentone) having AOR, CI and p-value of 8.1(1.8-36.2), p=0.006; 4.1(1.1-14.6), p=0.032; 3.4(1.110.9),p=0.04; 0.1(0.02-0.6), p=0.016;0.03(0.002-0.5),p=0.014 respectively. Conclusion and recommendation: The prevalence of inadequate depth of anesthesia was high (57%).