A study of arterial pH, bicarbonate levels, and base deficit at presentation as markers of predicting morbidity and mortality in acute pancreatitis

Background: The development of metabolic acidosis can occur commonly during critical illness. It is a clinical disturbance characterized by a low arterial pH, a reduced plasma HCO3− concentration, and compensatory hyperventilation. An extensive search for objective tools that predict severity and outcome at the time of hospital admission remains a major challenge. Patients and Methods: Patients with acute pancreatitis presenting to our unit between January 2012 and November 2013 were prospectively studied. Arterial blood gas (ABG) analysis was done at admission, and development of organ failure, any need for intervention, and mortality were noted. The association between various parameters of ABG analysis and the development of organ failure or local complications, need for interventions (endoscopic/radiological/surgical), and mortality were analyzed. Results: In all, 100 patients (mean age: 36.25 ± 12.86 years; 47.0% males and 53.0% females) were studied. The etiology of acute pancreatitis was Gall stone disease in 52 (52.0%), Alcoholism in 35 (35%), and others in 13 patients (13%). Of the 100 patients, acute fluid collections developed in 84 patients (84%). Multiple organ failure developed in 18 patients (18%). Respiratory failure developed in 68 patients (68%) and renal failure developed in 15 patients (15%), whereas 13 patients (13%) developed shock. Seven of the 19 patients (36.84%) with pH ≤7.35 died when compared with 1 of 81 patients (1.23%) with pH >7.35 (P = 0.001). Seven of the 58 patients (13.79%) with bicarbonate ≤24 mEq/L died when compared with 1 of 42 patients (2.38%) with bicarbonate >24 mEq/L (P = 0.05). Seven of 36 patients (19.4%) with base deficit ≥−4.0 died when compared with 1 of 64 patients (1.56%) with base deficit >4.0 (P = 0.002). Conclusion: Low arterial pH, low bicarbonate levels, and higher base deficit at presentation predict an adverse outcome with more frequency of organ failure, need for intervention, and mortality.