Laboratory factors and diagnostic aids for compartment syndrome in extracorporeal membrane oxygenation: An exploratory single-center study

Abstract

Purpose

Extracorporeal membrane oxygenation (ECMO) patients have increased risk for limb acute compartment syndrome (ACS), but diagnosis remains difficult given the lack of subjective and pulsatility assessments in this patient population. This exploratory study characterized ECMO patients who developed ACS and investigated laboratory measures that can aid diagnosis.

Methods

We reviewed records of adult patients placed on ECMO between 2016 and 2022 at our single center, collecting clinical, laboratory, and survival data upon cannulation. We performed comparisons of baseline and laboratory data between ACS and No ACS patients. Threshold regression was then used to develop laboratory cutoffs for ACS diagnosis and logistic regression to characterize predictors of ACS. Survival analysis relied on Cox proportional hazards modeling.

Results

278 ECMO patients were included, of which 14 (5%) developed ACS. ACS patients had a higher amputation rate (21.4% vs 1.9%, p < 0.001) and mortality risk (HR 2.35, p = 0.03); only 1 (7%) ACS patient had amputation-free survival. The most sensitive threshold cutoffs included maximum INR >1.95 (sensitivity 0.91), baseline lactate >7.85 (0.88), and 24-h lactate >3.75 (0.88). The most specific were baseline CpK >3765.5 (specificity 0.91), maximum K >5.95 (0.88), and maximum CpK >6362.0 (0.85). Laboratory values, namely CpK and lactate, predicted ACS with promising diagnostic sensitivity and specificity.

Conclusions

ACS remains associated with increased mortality and morbidity, most often occurring within 24 h after cannulation. Laboratory values, namely CpK and lactate values, independently predicted ACS development with promising sensitivity and specificity. These exploratory findings may help guide decision-making surrounding ACS in the ECMO setting.