Prevalence of preoperative metabolic disturbances in elderly patients with hip fracture and their association with mortality - A retrospective cohort study

STUDY OBJECTIVES

To assess the prevalence of preoperative acidosis and lactatemia in elderly patients having hip fracture surgery and their association with post-operative mortality.

DESIGN

Retrospective cohort study.

SETTING

Single tertiary medical center.

PATIENTS

Patients ≥65 years having first traumatic hip fracture surgery between 2018 and 2021.

MEASUREMENTS

90-day postoperative mortality.

MAIN RESULTS

In total, 1267 patients were included in the primary analysis (mean (SD) age 83(8) years; 802 (69%) females; median [Interquartile Range (IQR)] American Society of Anesthesiologists (ASA) physical score 3 [2,3]). Of these, 1227 were available for the multivariable analyses. Median [IQR] time from hospitalization to surgery was 28 [20, 42] hours. All-cause 90-day mortality rate was 9% (N = 114). The incidence of preoperative acidosis (pH < 7.35) and lactatemia (>1.2 mmol/L) was significantly higher among non-survivors. Mortality was highest in patients with both acidosis and lactatemia (19.1% compared to 4.4% among patients with neither). In a multivariable model, pH <7.35 and lactate >1.2 mmol/L remained independent predictors of 90-day mortality, with adjusted odds ratio (aOR) (95%CI) of 1.99 (1.31 to 3.04) and 2.32 (1.44 to 3.74), respectively, p = 0.001 for both. Time from hospitalization to surgery was not associated with mortality after adjustment for metabolic indices, aOR 1.00 (0.99, 1.00).

CONCLUSIONS

Preoperative acidosis and lactatemia are common among patients ≥65 years having hip fracture surgery and are associated with 90-day all-cause mortality. Time from hospital admission to surgery is not an independent risk factor, once adjusted for metabolic indices. Future studies should evaluate whether the increased risk associated with preoperative metabolic disturbances is modifiable.