# The exploration of perioperative hypotension subtypes: a prospective, single cohort, observational pilot study

## TL;DR

This pilot study explores different types of low blood pressure during surgery and finds that most patients experience it, often with reduced heart output.

## Contribution

The study identifies subtypes of perioperative hypotension and their association with cardiac output reduction in noncardiac surgery patients.

## Key findings

- 83% of patients experienced perioperative hypotension, with a median duration of 8 minutes.
- 77% of hypotension episodes were associated with reduced cardiac output.
- Patients with postoperative complications had longer and more extensive hypotension exposure.

## Abstract

Hypotension is a risk factor for postoperative complications, but evidence from randomized trials does not support that a higher blood pressure target always leads to optimized outcomes. The heterogeneity of underlying hemodynamics during hypotension may contribute to these contradictory results. Exploring the subtypes of hypotension can enable optimal management of intraoperative hypotension.

This is a prospective, observational pilot study. Patients who were ≥ 45 years old and scheduled to undergo moderate-to-high-risk noncardiac surgery were enrolled in this study. The primary objective of this pilot study was to investigate the frequency and distribution of perioperative hypotension and its subtypes (hypotension with or without cardiac output reduction). The exposure of hypotension and its subtypes in patients with and without myocardial or acute kidney injury were also explored.

Sixty patients were included in the analysis. 83% (50/60) of the patients experienced perioperative hypotension. The median duration of hypotension for each patient was 8.0 [interquartile range, 3.1–23.3] minutes. Reduced cardiac output was present during 77% of the hypotension duration. Patients suffering from postoperative myocardial or acute kidney injury displayed longer duration and more extensive exposure in all hypotension subtypes. However, the percentage of different hypotension subtypes did not differ in patients with or without postoperative myocardial or acute kidney injury.

Perioperative hypotension was frequently accompanied by cardiac output reduction in moderate-to-high-risk noncardiac surgical patients. However, due to the pilot nature of this study, the relationship between hypotension subtypes and postoperative myocardial or acute kidney injury still needs further exploration.

https://www.chictr.org.cn/showprojEN.html?proj=134260, CTR2200055929.