Acid Base Electrolyte Imbalance and Survival Outcome of Low Glasgow Coma Scale (GCS) patients in the Medical Intensive Care Unit

Background: Acid-base and electrolytes disorders are commonly seen in critically ill patients. Electrolyte abnormalities were the most frequent extra cranial occurrence of altered consciousness. There are multiple studies which reported altered survival outcome in low GCS patient and some did not. Aims: To assess the survival outcome of acid-base electrolyte imbalance associated with low GCS patients in the medical ICU. Methods: This retrospective, cohort study conducted in the medical ICU of a tertiary center in Chennai, India, for a period of six months included patients above 18 years old with various acid-base and electrolyte imbalances. During the study period of six months, a total of 276 patients were admitted in the medical ICU. Among these 100 patients were included in the study after excluding the patients who didn’t meet the inclusion criteria and those that had incomplete medical records. Following data were collected from medical records admission history, age, sex, anion gap, serum electrolytes, ABG, BUN, creatinine, PCO2, PO2, GCS and days in ICU. Results were analyzed and outcomes were noted (patient discharged, dies or seeks discharge against medical advice). Results: The study population included 68 male and 32 female with a mean age of 47.24±17.54 years. Metabolic acidosis was seen in 67% of patients. Mortality was significantly higher in patients with low GCS (51.06% vs. 20.75%, p<0.0001). Sodium and chloride increased significantly (p=0.0126, 0.0464 respectively) and potassium decreased significantly (p=0.0008) when GCS was low. The patients with hypernatremia and metabolic acidosis had 71.44% mortality rate. The patients with a low GCS have a higher incidence for multiple electrolyte disturbances. Low GCS leads mostly to an increased mortality especially in the patients with acid base disorders with electrolyte disorders compared to those with pure acid-base disturbances. To identify prognostic factors of the patients in the ICU, we performed multiple regression analysis using the data we collected. Among all the variables only three independent factors (GCS, BUN and Creatinine) significantly correlated with the criterion. Conclusions: Electrolyte and acid base disturbances should be seriously considered in low GCS patients to allow timely and appropriate therapeutic intervention to improve survival outcome.