Inhalation Anaesthesia Compared with Total Intravenous Anaesthesia and Postoperative Complications in Colorectal Cancer Surgery: An Observational Registry-Based Study.

Hasselager, R.P., Hallas, J. and Gögenur, I

British Journal of Anaesthesia 2022; 129 (3): 416-26. DOI: https://doi.org/10.1016/j.bja.2022.03.019

Aim of Study

• To investigate whether there is an association between the type of anaesthesia (inhalational vs total intravenous) and risk of post-operative complications after colorectal cancer surgery

Design and Location

• Denmark; observational study

Methodology

• Patient selection: Danish national registries of patients undergoing colorectal cancer surgery from 2004 to 2018 (Total number of patients: 22, 179 included 40.9% of total eligible)
• Known potential confounders accounted for by using a propensity score matching approach
• 8722 in each group (TIVA vs inhaled volatile anaesthesia)

 

Primary Outcome

• Any complications within 30 days postoperatively

Secondary Outcomes

• Any surgical complications within 30 days postoperatively
• Any medical complications within 30 days postoperatively
• 30-day mortality 

 

Statistics

• Pre-data collection analysis done: 2,402 individuals required as a minimum in each group to detect a 20% relative difference between groups (if postoperative complications rate is around 15% and significance set to 0.05 with study powered to 80%)
• Effect estimates for outcomes computed by using logistic regression and presented as odds ratio with 95% CIs

 

Results

• Fewer total post-operative complications occurred in the inhaled anaesthesia cohort – OR 0.84 (0.79-0.91)
• Fewer surgical complications occurred in the inhaled anaesthesia cohort – OR 0.76 (0.71-0.83)
• No difference in medical complications

Conclusions/Discussions

• Inhalational anaesthesia associated with fewer complications than TIVA for colorectal cancer surgery
• Hypothesis generated. Further randomised controlled study required to ascertain causality.

Limitations from the Study

• Propensity scoring does not address unmeasurable or unknown confounders
• Statistically significant does not exclude the possibility that results occurred due to chance
• Can only draw an association from an observational study not causation
• Structure of care probably matters more than the exact details of care

Summary by Dr P Nalwaya. Journal Club Meeting 13 October 2022.