Arterial pulse pressure and postoperative morbidity in high-risk surgical patients.

Ackland G, Abbott TEF, Pearse RM, Karmali SN, Whittle J, Minto
G; POM-HR Study Investigators.

Br J Anaesth. 2018 Jan;120(1):94-100. doi: 10.1016/j.bja.2017.11.009. Epub 2017
Nov 21.

BACKGROUND: Systemic arterial pulse pressure (systolic minus diastolic pressure)
≤53 mm Hg in patients with cardiac failure is correlated with reduced stroke
volume and is independently associated with accelerated morbidity and mortality.
Given that deconditioned surgical and heart failure patients share similar
cardiopulmonary physiology, we examined whether lower pulse pressure is
associated with excess morbidity after major surgery.
METHODS: This was a prospective observational cohort study of patients deemed by
their preoperative assessors to be at higher risk of postoperative morbidity.
Preoperative pulse pressure was calculated before cardiopulmonary exercise
testing. The primary outcome was any morbidity (PostOperative Morbidity Survey)
occurring within 5 days of surgery, stratified by pulse pressure threshold ≤53 mm
Hg. The relationship between pulse pressure, postoperative morbidity, and oxygen
pulse (a robust surrogate for left ventricular stroke volume) was examined using
logistic regression analysis (accounting for age, sex, BMI, cardiometabolic
co-morbidity, and operation type).
RESULTS: The primary outcome occurred in 578/660 (87.6%) patients, but
postoperative morbidity was more common in 243/ 660 patients with preoperative
pulse pressure ≤53 mm Hg{odds ratio (OR): 2.24 [95% confidence interval (CI):
1.29-3.38]; P<0.001). Pulse pressure ≤53 mm Hg [OR:1.23 (95% CI: 1.03-1.46);
P=0.02] and type of surgery were independently associated with all-cause
postoperative morbidity (multivariate analysis). Oxygen pulse <90% of
population-predicted normal values was associated with pulse pressure ≤ 53 mm Hg
[OR: 1.93 (95% CI: 1.32-2.84); P=0.007].
CONCLUSIONS: In deconditioned surgical patients, lower preoperative systemic
arterial pulse pressure is associated with excess morbidity. These data are
strikingly similar to meta-analyses identifying low pulse pressure as an
independent risk factor for adverse outcomes in cardiac failure. Low preoperative
pulse pressure is a readily available measure, indicating that detailed
physiological assessment may be warranted.