Hyperchloremic acidosis is frequent in critically ill patients. Renal tubular acidosis (RTA) may contribute to acidemia in the state of hyperchloremic acidosis, but the prevalence of RTA has never been studied in critically ill patients. Therefore, we aimed to investigate the prevalence, type, and possible risk factors of RTA in critically ill patients using a physical-chemical approach.~This prospective, observational trial was conducted in a medical ICU of a university hospital. 100 consecutive critically ill patients at the age ≥18, expected to stay in the ICU for ≥24h, with the clinical necessity for a urinary catheter and the absence of anuria were included.~Base excess subset calculation based on a physical-chemical approach on the first seven days after ICU admission was used to compare the effects of free water, chloride, albumin, and unmeasured anions on the standard base excess. Calculation of the urine osmolal gap (UOG) - as an approximate measure of the unmeasured urine cation ammonium - served as determinate between renal and extra-renal bicarbonate loss in the state of hyperchloremic acidosis.
The aim of this study was to investigate the prevalence, type, and possible risk factors of RTA in critically ill patients using a physical-chemical approach.