Association between general anesthesia combined with peripheral nerve blocks versus neuraxial anesthesia without nerve blocks for high-risk isolated distal deep venous thrombosis in patients undergoing knee arthroplasty: a historical cohort study.

PURPOSE

General anesthesia combined with peripheral nerve blocks has become a common anesthesia regimen for knee replacement surgery. Its association with high-risk isolated distal deep venous thrombosis (IDDVT) remains uncertain.

METHODS

In this cohort study, we obtained consecutive data from the electronic inpatient records of Shenzhen Second People's Hospital, including adults who underwent knee arthroplasty from 1 September 2019 to 31 August 2021. The primary outcome was the incidence of high-risk IDDVT. We compared the outcomes in patients who received general anesthesia combined with nerve blocks with those in patients who received neuraxial anesthesia without nerve blocks, using a multivariable regression model with inverse probability weighting according to the propensity score.

RESULTS

Of the 848 patients who underwent knee arthroplasty, 330 were excluded because they lacked thrombus testing or had received other types of anesthesia. Of the remaining 518 patients, 267/518 (52%) received general anesthesia combined with nerve blocks and 251/518 (48%) received neuraxial anesthesia with no nerve blocks. A total of 99 patients developed high-risk IDDVT. In the primary multivariable analysis with inverse probability weighting according to the propensity score, general anesthesia combined with nerve blocks was associated with a significantly reduced high-risk IDDVT compared with neuraxial anesthesia without nerve blocks (odds ratio, 0.50; 95% confidence interval, 0.31 to 0.81; P = 0.005). The results of multiple sensitivity analyses were similar between the two cohorts. E-value analysis suggested robustness to unmeasured confounding.

CONCLUSIONS

Compared with neuraxial anesthesia without peripheral nerve blocks, general anesthesia combined with peripheral nerve blocks in patients undergoing knee arthroplasty was associated with a reduced incidence of high-risk IDDVT in our retrospective study. A large multicentre prospective clinical trial is needed to validate our findings.

STUDY REGISTRATION

ChiCTR.org.cn ( ChiCTR2200057006 ), first submitted 25 February 2022.