FO005
MEASURING AND PRESCRIBING BICARBONATE IN CHRONIC KIDNEY DISEASE PATIENTS. A SURVEY AMONG EUROPEAN NEPHROLOGISTS. Free

INTRODUCTION AND AIMS: To evaluate practices among nephrologists in measuring bicarbonate levels (HCO₃) and in prescribing oral bicarbonate, in order to identify and correct metabolic acidosis of Chronic Kidney Disease (CKD) patients.

METHODS: A 16-item questionnaire was sent and distributed or posted on the websites of European Renal Societies. Responses were returned and analysed.

RESULTS: Three hundred sixty one valid responses from 22 countries were collected. We found that measurement of HCO₃ is increasing with progressing of CKD, with 52% of respondents measuring them in every visit and 22% in most of the visits at CKD stage 5 not on dialysis. However routine measurement of HCO₃ in hemodialysis (HD) patients is performed only by 42% of the respondents and by 43% only if considered “necessary”. Respective percentages are 51% and 39% for peritoneal dialysis patients. Routine measurement is done every month in 70% of the cases. Only 19% of the participants are measuring HCO₃ after the dialysis session routinely and 53% not at all. Most of the respondents (60%) measure HCO₃ using a blood gas analyser (arterial or venous blood) and 40 % are measuring serum HCO₃ together with other blood tests. Oral bicarbonate is prescribed to correct acidosis in the advanced stages of CKD and 89% of participants responded that they use it more than often in CKD stage 5 patients not on dialysis. However prescription of oral bicarbonate fall in HD (16%) and peritoneal dialysis (18%) patients. When prescribing oral bicarbonate in CKD patients, most of the respondents (38%) start when HCO₃ fall below 22meq/L or below 18 meq/L (37%). Of them, 36% aim to a target HCO₃ of 18-22 meq/L, 28% to 23-29 meq/L and 23% to 24-26 meq/L. We observed that practices are not the same among nephrologists. In binary logistic regression analysis we found that respondents who measure serum HCO₃ are more likely to measure them routinely than those who are using a blood gas analyser; in HD patients the odds ratio is 13.67 (95%CI: 7.83-23.87, p <0.001). In addition participants who measure routinely HCO₃ are more likely to prescribe oral bicarbonate; in HD patients the odds ratio is 3.38 (95%CI: 1.75-6.52, p <0.001).

CONCLUSIONS: Measurement of HCO₃ is not routine practice for all the nephrologists. Inclusion of serum HCO₃ in the blood tests performed by the biochemistry laboratory can increase its use in CKD patients as it is less cumbersome than blood gas analysis. This in turn may increase prescription of oral bicarbonate to correct metabolic acidosis.