The Relation Between Mean Arterial Pressure and Cardiac Index in Major Abdominal Surgery Patients: A Prospective Observational Cohort Study

TY - JOUR

T1 - The Relation Between Mean Arterial Pressure and Cardiac Index in Major Abdominal Surgery Patients: A Prospective Observational Cohort Study

AU - Kouz, Karim

AU - Bergholz, Alina

AU - Timmermann, Lea M

AU - Brockmann, Lennart

AU - Flick, Moritz

AU - Hoppe, Phillip

AU - Briesenick, Luisa

AU - Schulte-Uentrop, Leonie

AU - Krause, Linda

AU - Maheshwari, Kamal

AU - Sessler, Daniel I

AU - Saugel, Bernd

N1 - Copyright © 2021 International Anesthesia Research Society.

PY - 2022/2/1

Y1 - 2022/2/1

N2 - BACKGROUND: Cardiac output is an important hemodynamic variable and determines oxygen delivery. In contrast to blood pressure, cardiac output is rarely measured even in high-risk surgical patients, suggesting that clinicians consider blood pressure to be a reasonable indicator of systemic blood flow. However, the relationship depends on constant vascular tone and volume, both of which routinely vary during anesthesia and surgery. We therefore tested the hypothesis that there is no clinically meaningful correlation between mean arterial pressure and cardiac index in major abdominal surgery patients.METHODS: In this prospective observational study, we assessed the relationship between mean arterial pressure and cardiac index in 100 patients having major abdominal surgery under general anesthesia.RESULTS: The pooled within-patient correlation coefficient calculated using meta-analysis methods was r = 0.34 (95% confidence interval, 0.28-0.40). Linear regression using a linear mixed effects model of cardiac index on mean arterial pressure revealed that cardiac index increases by 0.014 L·min-1·m-2 for each 1 mm Hg increase in mean arterial pressure. The 95% Wald confidence interval of this slope was 0.011 to 0.018 L·min-1·m-2·mm Hg-1 and thus within predefined equivalence margins of -0.03 and 0.03 L·min-1·m-2·mm Hg-1, thereby demonstrating lack of clinically meaningful association between mean arterial pressure and cardiac index.CONCLUSIONS: There is no clinically meaningful correlation between mean arterial pressure and cardiac index in patients having major abdominal surgery. Intraoperative blood pressure is thus a poor surrogate for cardiac index.

AB - BACKGROUND: Cardiac output is an important hemodynamic variable and determines oxygen delivery. In contrast to blood pressure, cardiac output is rarely measured even in high-risk surgical patients, suggesting that clinicians consider blood pressure to be a reasonable indicator of systemic blood flow. However, the relationship depends on constant vascular tone and volume, both of which routinely vary during anesthesia and surgery. We therefore tested the hypothesis that there is no clinically meaningful correlation between mean arterial pressure and cardiac index in major abdominal surgery patients.METHODS: In this prospective observational study, we assessed the relationship between mean arterial pressure and cardiac index in 100 patients having major abdominal surgery under general anesthesia.RESULTS: The pooled within-patient correlation coefficient calculated using meta-analysis methods was r = 0.34 (95% confidence interval, 0.28-0.40). Linear regression using a linear mixed effects model of cardiac index on mean arterial pressure revealed that cardiac index increases by 0.014 L·min-1·m-2 for each 1 mm Hg increase in mean arterial pressure. The 95% Wald confidence interval of this slope was 0.011 to 0.018 L·min-1·m-2·mm Hg-1 and thus within predefined equivalence margins of -0.03 and 0.03 L·min-1·m-2·mm Hg-1, thereby demonstrating lack of clinically meaningful association between mean arterial pressure and cardiac index.CONCLUSIONS: There is no clinically meaningful correlation between mean arterial pressure and cardiac index in patients having major abdominal surgery. Intraoperative blood pressure is thus a poor surrogate for cardiac index.

U2 - 10.1213/ANE.0000000000005805

DO - 10.1213/ANE.0000000000005805

M3 - SCORING: Journal article

C2 - 34854823

VL - 134

SP - 322

EP - 329

JO - ANESTH ANALG

JF - ANESTH ANALG

SN - 0003-2999

IS - 2

ER -