Electrolyte and Metabolic Disturbances in Ebola Patients during a Clinical Trial, Guinea, 2015

Abstract

By using data from a 2015 clinical trial on Ebola convalescent-phase plasma in Guinea, we assessed the prevalence of electrolyte and metabolic abnormalities at admission and their predictive value to stratify patients into risk groups. Patients underwent testing with a point-of-care device. We used logistic regression to construct a prognostic model and summarized the predictive value with the area under the receiver operating curve. Abnormalities were common among patients, particularly hypokalemia, hypocalcemia, hyponatremia, raised creatinine, high anion gap, and anemia. Besides age and PCR cycle threshold value, renal dysfunction, low calcium levels, and low hemoglobin levels were independently associated with increased risk for death. A prognostic model using all 5 factors was highly discriminatory (area under the receiver operating curve 0.95; 95% CI 0.90-0.99) and enabled the definition of risk criteria to guide targeted care. Most patients had a very low (<5%) or very high (>80%) risk for death.

Keywords: EVD; Ebola; Guinea; clinical trial; death; electrolyte; infectious disease; metabolic; model; mortality; point of care; prediction; risk; viruses.

Figure 1

Histogram displaying the distribution of the risk for death for Ebola patients recruited for the Ebola-Tx trial, Conakry, Guinea, 2015, according to a 5-variable point-of-care (POC+) prognostic prediction model. POC+ model includes 3 POC measurements (blood creatinine, calcium, and hemoglobin) plus the cycle threshold value of the diagnostic Ebola PCR result and the age of the patient. ETU, Ebola treatment unit.

Figure 2

Receiving operating curve summarizing the performance of 3-variable point-of-care (POC) and 5-variable POC+ prognostic prediction models for Ebola patients recruited for the Ebola-Tx trial, Conakry, Guinea, 2015. POC model includes blood creatinine, hemoglobin, and calcium levels. POC+ model includes the same 3 POC measurements plus the cycle threshold value of the diagnostic Ebola PCR result and the age of the patient. AUROC, area under the receiver operating curve; POC, point-of-care.