Postoperative Lactate Levels and Hospital Length of Stay After Cardiac Surgery

Abstract

Objectives: The objective of this study was to characterize the association between lactate levels and hospital length of stay (LOS) after cardiac surgery.

Design: A retrospective study using prospectively collected data from the Society of Thoracic Surgeons adult cardiac surgery database.

Setting: A tertiary-care hospital.

Participants: Patients in the database who presented for major cardiac surgery between 2002 and 2014 and whose lactate level was measured within 3 hours after skin closure.

Interventions: None.

Measurements and main results: The authors performed multivariable linear regression with adjustment for more than 30 variables to assess the association between postoperative lactate levels and hospital LOS. The study included 1,208 patients whose median LOS was 6 days (quartiles: 5, 9). Median LOS in the low-, moderate-, and high-lactate groups was 5 days (quartiles: 4, 7), 6 days (quartiles: 5, 9) and 9 days (quartiles: 6, 17), respectively; p<0.001. In multivariable analysis, patients with a moderate lactate level had a 1.08 times (95% CI: 1.00-1.17; p = 0.04) longer LOS compared with those with a low lactate level. Patients with a high lactate level had a 1.12 times (95% CI: 1.00-1.26; p = 0.04) longer LOS compared with those with a low lactate level. Lactate levels also were associated with intensive care unit LOS and nonsurgical postoperative complications.

Conclusions: Postoperative lactate levels are associated with increased hospital LOS for patients undergoing major cardiac surgery.

Keywords: cardiac surgery; coronary artery bypass grafting; lactate; length of stay; morbidity; valve surgery.