METABOLIC ACIDOSIS--AN UNDERESTIMATED PROBLEM AFTER KIDNEY TRANSPLANTATION?

Despite prolonged survival and better quality of life as compared to dialysis, kidney transplantation frequently presents with a complex set of medical issues that require intensive management to protect graft function. Metabolic acidosis has an impact on several metabolic complications such as mineral and muscle metabolism, nutritional status and anemia. It may also have an effect on graft function, possibly through the stimulation of adaptive mechanisms aimed at maintaining acid-base homeostasis. We investigated current practice in the evaluation of metabolic acidosis at one of the largest transplant centers in the Eurotransplant region. Adult renal transplant recipients having received allograft from January 2011 to August 2012 were included in the investigation. We recorded the frequency of measuring the parameters of venous blood gas analysis, as well as creatinine and urea levels, creatinine clearance, proteinuria, calcium, phosphate and potassium blood levels, body mass index and the time spent on dialysis prior to kidney transplantation. Out of 203 patients who had received renal allograft at our institution during the observed period, 191 (124 males and 67 females, age range from 18 to 77 years) were enrolled in the study. Of these, only 92 (48.167%) patients had parameters of venous blood gas analysis measured at some time after kidney transplantation. Acid-base status was determined more often in males (77 males vs. 22 females, p = 0.001). Patients with pH/blood gas analysis performed were found to have significantly higher creatinine and urea levels and significantly lower creatinine clearance (p < 0.001 both). Serum calcium levels were also significantly lower in this group of patients (p < 0.001). Metabolic acidosis is a very important clinical issue that needs to be monitored in every transplant recipient. Its effects on graft function, nutritional status, anemia and bone mass are complex but can be successfully managed. Our study showed metabolic acidosis to be linked with significantly higher creatinine and urea levels, decreased creatinine clearance and lower calcium levels. Nevertheless, metabolic acidosis still stays a highly underestimated problem among nephrologists dealing with transplant recipients. We suggest regular determination of the acid-base status in renal transplant recipients.