Changes in selected electrolytes in adult intensive care patients at the University Teaching Hospital, Lusaka, Zambia

Abstract

The importance of regulating potassium and sodium levels is well recognized in most Intensive Care Units (ICU). Various institutions across the globe have found varying figures on the extent and causes of electrolytes derangements in ICUs. Some tertiary hospitals in Africa similar to the University Teaching Hospital (UTH), Lusaka, have reported prevalence’s of over 66% of the patients in ICU having multiple electrolyte abnormalities. However, the extent of electrolyte derangements in patients admitted to the Main Intensive Care Unit (MICU) at UTH, Lusaka, Zambia is unknown. This study aimed to evaluate the twenty-four-hour changes in selected electrolytes in adult patients admitted to MICU at UTH, Lusaka, Zambia. An Observational Cross-Sectional Study. Blood samples obtained from a peripheral vein in Heparinized bottles for renal function tests were measured using the Beckman Counter/Au480 (Serial: 2013102691) machine at UTH. Normal serum concentrations of sodium and potassium were considered as 135-145 and 3.5 - 4.5mmol/L, respectively. Statistical analysis was performed with Stata. A total number of one hundred (100) patients were enrolled in this study with a mean age of 36.8 (SD = 12.1). The mean value of sodium level was 136.7 (SD = 8.9) mmol/L and 139.0 (SD = 11.6) mmol/L, on admission and 24 hours post admission respectively. This difference in serum sodium level was shown to be statistically significant with a P-value = 0.005. Hypernatremia was shown to be associated with an increased risk of death (p = 0.02) in the Unit with an odds ratio of 4.3at 95% confidence interval of 1.3 to 13.9. Hyponatremia was the most prevalent electrolyte imbalance but was neither shown to be associated with mortality (P-value = 0.2) nor prolonged ICU stay at 24 hours post admission. The mean value of potassium level was 4.2 (SD = 1.1) mmol/L and 4.3 (SD = 1.1), on admission and 24 hours post admission respectively. This difference was shown to be not statistically significant (P-value = 0.6). Neither hypokalaemia (p = 0.2) nor hyperkalaemia (p = 0.1) were associated with mortality at 24 hours post admission and there was no association with duration of stay in ICU. There is a significant change in serum sodium levels after 24 hours post admission but there is no significant change in potassium level. Hyponatremia being the most prevalent. Hypernatremia remains significantly associated with mortality and therefore, correcting electrolyte imbalances in ICU patients is an urgent necessity. vi Keywords: Hypernatremia, Hyponatremia, Hypokalaemia, Hyperkalaemia, Electrolytes