Etiology and Clinico-biochemical Profile of Patients Admitted to Medicine ICU or Ward with Metabolic Acidosis in Eastern India

Abstract

Aims: To understand the etiologies and clinical profile of metabolic acidosis in patients’ admitted to medicine ICU or ward. To study biochemical parameters and their prognostic importance like the following:- 1.serum cations ( Na+, k+ ,Ca+2 ,Mg+2 ) 2.serum anions (Cl-, HCO3-, PO4-3, albumin-, lactate-) 3.Sao2; Pao2; Paco2 4.base excess 5.anion gap, strong ion gap, strong ion difference 6.(Na+-Cl-); (Cl- /Na+); (Cl- -HCO3-) ;(Cl - / HCO3-) 7.blood pH 8.urinary pH. Study Design: Cross-sectional study Place and Duration of Study: Postgraduate Department of Medicine, SCB Medical College and Hospital, Cuttack, Odisha, India between August 2011 and July 2012. Methodology: 100 consecutive patients diagnosed following analysis of arterial blood gas (ABG) and electrolytes. Inclusion criteria: - 1. All cases clinically suspected to have acid base imbalance and found to have low HCO3- along with low or normal pH. 2. All cases with high anion gap even with normal pH and HCO3-. Respiratory compensation, AG, delta ratio, SIDe, SIG, SIDa were calculated. Results: Among 100 cases 61 were primary metabolic acidosis, 39 cases were mixed acid base disorders. Among etiologies 32% were lactic acidosis, 13% ketoacidosis, 30% chronic renal failure, 3% poisoning, 19% diarrhea, 3% renal tubular acidosis. Among causes of lactic acidosis septicemia accounted for 56%, heart failure 19%, hepatic failure 10%, malaria 9%, seizure 3%, malignancy 3%. Among keto acidosis diabetic ketoacidosis accounted for 69%, alcoholic ketoacidosis 31%. Among various clinical features tachypnea was noted in 96%, tachycardia 92%, clear chest 72%, altered sensorium 54%, hypotension 46%, decreased urination 46%, hypertension 39%, vomiting 36%, diarrhea 29%, abdominal pain in 23% cases. By binary logistic regression lactate, phosphate, blood pH, PaCO2, SIG, AGc, SIDe, SIDa levels were independent predictors of mortality (p values 0.001, 0.001, 0.027, 0.044 ,0.003,0.035,0.001,0.001 respectively). Notably, base excess, Na+, K+, Ca+2, Mg+2, Cl-,HCO3- , (Na+ - Cl- ) , ( Cl- /Na+) (Cl- -HCO3- ), (Cl - / HCO3- ), urinary pH, PaO2, SaO2 were not predictors of mortality. Conclusion: Lactic acidosis, and chronic renal failure were common etiologies. Tachycardia, tachypnea with clear chest, altered sensorium were common clinical manifestations. Lactate, phosphate, blood pH, paCO2, SIG, AGc, SIDe, SIDa were significant predictors of mortality.