Importancia del concepto «fosfatemia adecuada» como factor de riesgo de hiperfosfatemia / Physician misconception of “adequate phosphatemia” may be a determinant factor for hyperphosphatemia

RESUMEN

En 1999 GEMOR realizó una encuesta entre centros de diálisis de Argentina para conocer la realidad de dicha patología en el país. Presentamos los resultados relacionados al fósforo. Participaron 80 centros de diálisis (24% de los centros nacionales), donde dializaban 4.512 pacientes (34% del país). El 95% determinaban Calcio y Fósforo sérico en forma mensual. El 83,5% pretendía en sus pacientes una fosfatemia entre 4,5 y 5,5 mg/dl, mientras que en el 10,1% el objetivo estaba entre 5,5 y 6,5 mg/dl. La media porcentual de fosfatemia superior a 6 mg/dl fue del 28,8 ± 15,9%. Cinco de 77 centros reportaron que no tenían pacientes hiperfosfatémicos en la última determinación mensual. Los que pretendían una fosfatemia entre 5,5 y 6,5 mg/dl, tenían un porcentaje de pacientes con fosfatemia mayor de 6 mg/dl superior a aquellos que pretendían entre 4,5 y 5,5 mg/dl (42,8 ± 16,7 vs 27,1 ± 15,2% respectivamente, p = 0,007). Mientras que la media de fosfatemia también fue superior (6,4 ± 0,7 vs 5,3 ± 0,7 mg/dl respectivamente, p = 0,0001). Esto sugiere que los centros donde se pretendía mayor fosfatemia tenían más casos de hiperfosfatemia. Existen centros sin pacientes hiperfosfatémicos. Esto supone o un buen control de la fosfatemia o resultados de laboratorio «falsos negativos» (AU)

ABSTRACT

Hyperphosphatemia is an important risk factor of secondary hyperparathyroidism and extraosseous calcifications in chronic renal failure patients. In this study our hypothesis is that physicians misconception of adequate phosphatemia is a risk factor for hyperphosphatemia. In 1999 GEMOR sent a renal osteodystrophy inquiry to different hemodialysis centers in Argentina. It included 80 dialysis centers in 17 Argentinian provinces. The enquire had 33 questions about renal osteodystrophy. Here we report the section related to phosphorous metabolism. We obtained responses from 80 dialysis centers (4,512 dialysis patients), which represents about 24% of Argentinian dialysis centers. Physicians considered phosphorous levels between 4.5 to 5.5 mg/dl in 83.5% of centers as adequate, and between 5.5 to 6.5 mg/dl in 10.1%. Five out of 77 centers reported that they had no patients with hyperphosphatemia. The percentage of hemodialysis patients that had more than 6 mg/dl in each center was 28.8 ± 15.9%. Those centers that aimed for phosphatemia between 5.5 and 6.5 mg/dl, had a higher percentage of patients with phosphatemia above 6 mg/dl than those aiming for between 4.5 and 5.5 mg/dl (42.8 ± 16.7 vs 27.1 ± 15.2% respectively, p = 0.007), and had higher mean of phosphatemia (6.4 ± 0.7 vs 5.3 ± 0.7 mg/dl respectively, p = 0.0001), than the last group. In conclusion, a higher mean phosphate level was obtained in hemodialysis centers where physicians considered higher pre-dialysis target levels. Some centers had no patients with hyperphosphatemia (neglect or good control?) (AU)