General anaesthesia prolongs hospital stay after total knee arthroplasty

The use of general anaesthesia (GA) seems to prolong hospital length of stay (LOS) among patients undergoing unilateral total knee arthroplasty (TKA), according to a recent Singapore study.

“Our study showed that GA is associated with a longer LOS during unilateral TKA compared with regional anaesthesia (RA); [t]his can be taken into account when choosing the type of anaesthesia before surgery,” the researchers said. “This finding needs to be validated in future studies.”

In the current cohort of 2,622 TKA patients (mean age 66.57±8.23 years, 24.18 percent men), 1,560 underwent the procedure under RA, while 806 were given GA. The GA group was significantly younger (p<0.05) and had a lower proportion of men (p<0.05) than RA. In comparison, baseline body mass index, smoking, blood biomarker profile, and duration of surgery were comparable between groups. [BMC Anesthesiol 2021;21:242]

The mean LOS in the whole cohort was 5.37±4.87 days. Patients who were put under GA had a mean LOS of 5.92±6.20 days, significantly longer than that in RA patients, who were in the hospital for an average of 5.09±3.98 days (p<0.001).

Unadjusted linear regression analyses showed that GA was a significant correlate of longer hospital LOS. In particular, the unadjusted odds ratio (OR) effect size estimate obtained was 1.33 (95 percent confidence interval [CI], 1.08–1.64), indicating that the proportion of patients with LOS >6 days was 33-percent higher in the GA vs RA group.

Adjusting for age, sex, ethnicity, physical status, comorbidities, blood biomarker profile, and other operative and clinical factors, the researchers confirmed that GA was significantly and independently correlated with longer LOS (β, 0.93, 95 percent CI, 0.54–1.32; p<0.0001). The OR estimate was 1.45 (95 percent CI, 1.15–1.84; p=0.0016), suggesting that GA patients were 45-percent more likely to have LOS >6 days than their RA counterparts.

The principal findings were robust to subgroup analysis, such that stratification according to blood biomarkers, lifestyle, duration of surgery, and various demographic factors did not attenuate the significant effect of GA on LOS.

“Due to current medical factors, such as medical insurance cost control efforts, large numbers of waitlisted inpatients, and reduced numbers of specialized orthopaedic beds at the hospital, patient LOS has certain constraints, and the entire process of knee rehabilitation cannot be completed during hospitalization,” the researchers said.

“Choosing the right anaesthesia method to reduce the patient’s hospitalization duration is a very effective method for shortening the LOS. The clinical pathway for [faster] TKA rehabilitation surgery needs ongoing improvement and development,” they added.