# Comparison of total intravenous anesthesia and combined inhalation and intravenous anesthesia on survival after tumor surgery: a propensity score matched cohort study

## TL;DR

This study compares two anesthesia methods in cancer surgery and finds that combined inhalation and intravenous anesthesia may be linked to higher long-term mortality.

## Contribution

The study provides new evidence on the potential impact of combined inhalation and intravenous anesthesia on cancer patient survival.

## Key findings

- Combined inhalation and intravenous anesthesia was associated with increased 3-year mortality risk.
- No significant association was found between the anesthesia method and short-term mortality.
- Propensity score matching confirmed the link between the anesthesia method and long-term mortality.

## Abstract

Prior studies have indicated that inhalation anesthesia in cancer surgery might heighten the risk of tumor metastasis and diminish patient survival. Yet, combined inhalation and intravenous anesthesia (CIVA), a prevalent general anesthesia technique, remains underexplored regarding its influence on postoperative survival in cancer surgery patients. To fill this gap, this study compares the short-term and long-term mortality of cancer surgery patients receiving CIVA versus total intravenous anesthesia (TIVA).

A retrospective cohort study was conducted at a tertiary care hospital in China, comprising 25,351 patients who underwent cancer surgery under general anesthesia between January 2014 and December 2018. The primary outcomes were short-term mortality (within 3 months) and long-term mortality (within 3 years). CIVA and TIVA were the primary exposures. Propensity score matching (PSM) was employed to adjust for confounding factors, and Cox regression models were utilized to estimate hazard ratios (HR) and 95% confidence intervals (CIs) for mortality outcomes.

Among the 25,351 patients who underwent tumor resection, 23,790 were administered TIVA, while 1,561 received CIVA. In the 1:3 PSM cohort, 1,536 patients received CIVA, and 4,519 patients received TIVA. The Cox regression models for the 1:1, 1:2, and 1:3 PSM cohorts indicated that CIVA was associated with long-term mortality but not with short-term mortality. The multivariable Cox regression model following 1:3 PSM revealed that CIVA was associated with an increased risk of 3-year mortality (HR: 1.220; 95% CI: 1.043–1.404).

Our results provided indirect evidence of potential hazard of inhaled anesthetics, even as a compound in CIVA, on long-term mortality after cancer surgery. Given the limitations of this retrospective study, further prospective work exploring the effect of anesthetic technique on mortality is urgently needed.