Hypotension in Regional Anesthesia and Rate of Injection

Abstract

Introduction. To present some thoughts on the article “Regional subarachnoid anesthesia for C-section and post-partum Pomeroy procedure. Application of a local anesthetic at a rate lower or greater than 60 seconds” in order to provide readers with a different perspective regarding the results reported.

Methods. The paper was read critically in order to assess the quality of the methodology, the potential sources of bias and error, the confounding variables, and also to review the results from a fresh perspective.

Results. Hypotension occurs frequently when subarachnoid anesthesia is applied, and the rate of injection may explain it in part. The case series analyzed has a limited sample size, creating the possibility of information bias and confounding factors, not to mention that the potential interaction between the rate of infusion and the mix of anesthetics was not considered.

Conclusion. A cohort study with a larger sample size must be undertaken in order to control confusion by means of standardized procedures, an analysis stratified by subgroups, and mathematical modeling designed to identify the strength of association between the injection rate and the onset of hypotension, as potential sources of confusion and interaction.