Serum phosphorus levels predict clinical outcome in fulminant hepatic failure

The aim of this pilot study was to evaluate the incidence of hypophosphatemia and its association with clinical outcome in fulminant hepatic failure (FHF). Patients with FHF referred for orthotopic liver transplantation (OLT) between January, 1991 and May, 2002 were identified. FHF was defined as the development of coagulopathy and encephalopathy within 8 weeks of onset of jaundice. Demographic and laboratory data, including serum phosphate, calcium, magnesium, creatinine, and PT/INR were obtained from medical records. Clinical outcomes (death, OLT, or hepatic recovery) and associated morbidities (renal failure, bleeding, and sepsis) also were noted. Thirty-eight patients, 8 men and 30 women, aged 34 +/- 4 years, were included in the study. Hypophosphatemia (< 2.5 mg/dL) developed in 33 of 38 (87%) patients within 10 days of referral. Twelve patients (32%) died, 14 patients (37%) underwent OLT, and 12 patients (32%) recovered. The mean nadir serum phosphorus level was significantly lower in those who recovered compared with those who either died or required OLT (1.18 +/- 0.54 versus 1.79 +/- 1.00 mg/dL; P =.02). A trend toward lower mean serum phosphorus level also was noted in those who recovered compared with those who died (1.18 +/- 0.54 versus 1.96 +/- 1.35 mg/dL; P =.09). Serum phosphorus levels > 2.5 mg/dL was a predictor of mortality, and when used alone, was equivalent to the King's College Criteria. In conclusion, hypophosphatemia occurred frequently in patients with FHF. Lower serum phosphorus levels were observed in patients who recovered as compared with those who died or required OLT, and may be associated with recovery of hepatic function. The greater decline in serum phosphorus level in those who recover hepatic function may represent cellular use of phosphorus during hepatocyte regeneration.