Acute Onset of Lactic Acidosis
Here is a case of a 71 year old woman with a history of CAD s/p left carotid endarterectomy, pulmonary hypertension on tadalafil and Home O2 therapy, symptomatic cholelithiasis, HTN, DM II (A1c 7.3%) presenting with two days of right sided flank pain. Described as sharp and constant, it radiates up to lower scapula border and is exacerbated with deep inspiration. Of note, these symptoms are different than the intermittent RUQ pain she endures for the past several months. Denies any F/C/N/V/hematuria or dysuria. No chest pain and at her baseline for dyspnea.
She arrives for further evaluation with an exam notable for a woman not in any acute distress with right lumbar paraspinal tenderness and questionable ipsilateral CVA tenderness with unremarkable labs. The next morning, her exam changes with more diffuse abdominal tenderness and hypotensive in the 80/40s. Additionally, her labs were now notable for a bicarb of 13 with anion gap of 21 (pH 7.21/25/9.8/75/92%). After a transfer to the MICU for further evaluation, CT abdomen and pelvis, Abdominal ultrasound, and HIDA were only remarkable for cholelithiasis. She improved within the next with the diagnosis of metformin-induced lactic acidosis.
Highlights of the discussion included:
*Brief review of the World Health Organization’s Classes of Pulmonary Hypertension
*Discussion of the three types of Lactic Acidosis: Type A (overproduction of lactate), Type B (impaired lactate metabolism), D-lactate acidosis (product of colonic bacteria)
*Exploring whether metformin use has increased risk of lactic acidosis in comparison to other oral hypoglycemics