Supplemental intraoperative oxygen did not increase postoperative mortality, Finds Study
Surgical site infections and wound-related complications are common and serious. The primary defence against bacterial infection is oxidative killing by neutrophils, which requires molecular tissue oxygen. Increasing inspired oxygen is an easy and effective way to augment tissue oxygen. However, a recent study suggests that supplemental oxygen did not increase postoperative mortality. The research has been published in the journal Anesthesiology on March 05, 2021.
The theory that supplemental oxygen might reduce the risk of surgical wound infection led to two decades of studies. While initial trials were supportive, subsequent large trials were not, and a recent meta-analysis of reliable trials suggests that supplemental oxygen at most slightly reduces the perioperative infection risk. However, the extent to which supplemental oxygen might promote long-term mortality, therefore, remains unclear. Therefore, Dr Qiliang Jiang, M.D. and his team conducted a study to test the hypothesis that supplemental oxygen (80% vs 30%) increases the hazard for long-term mortality.
It was a post hoc analysis of a large multiple crossover cluster trial in which more than 5,000 colorectal surgeries on 4,088 adults were allocated to receive either 30% or 80% inspired oxygen during general anaesthesia. The researchers evaluated the effect of 80% versus 30% target-inspired oxygen on long-term mortality and calculated Kaplan–Meier survival estimates. They identified a total of 3,471 qualifying colorectal surgeries performed in 2,801 patients and analyzed 1,753 (51%) surgeries in 1,577 patients who were given 80% oxygen and 1,718 surgeries in 1,551 patients who were given 30% oxygen.
Key findings of the study were:
- Upon analysis, they observed that the incidence of death after a median of 3 yr was 13% (234 of 1,753) in the 80% oxygen group and 14% (245 of 1,718) in the 30% oxygen group.
- They noted that the estimated hazard ratio for mortality was 0.94.
The authors concluded, " We performed a post hoc analysis of a large crossover cluster trial and evaluated whether intraoperative supplemental oxygen causes long-term mortality. Supplemental oxygen did not increase postoperative mortality overall, or in cancer patients, and can be safely used when deemed appropriate."
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