High Incidence of Hypophosphatemia in Surgical Intensive Care Patients: Efficacy of Phosphorus Therapy on Myocardial Function

Objective: To determine the incidence of hypophosphatemia in a surgical intensive care unit and to determine whether or not a phosphorus challenge causes a change in cardiac performance in hypophosphatemic patients.

Design: Prospective clinical study and case reports.

Setting: Surgical intensive care unit in an university hospital.

Patients: A total of 208 consecutive patients admitted to the surgical ICU were evaluated over a 6 months period.

Interventions: All classical risk factors for hypophosphatemia were recorded. A group of 8 moderate or severe hypophosphatemic patients were evaluated for hemodynamic data before and after a phosphorus load. Glucose phosphate was given over 30 min by the intravenous route. Dosage regimen was 0.4 mmol/kg weight for moderate hypophosphatemia and 0.8 mmol/kg weight for severe hypophosphatemia.

Results: Risk factors were present in 134 patients and 60 patients were hypophosphatemic (44.8%). Only 3 risk factors were discriminant for hypophosphatemia: sepsis, diuretics and total parenteral nutrition. The mortality was higher in the hypophosphatemic group than in the normophosphatemic group (30% versus 15.2%; p < 0.05). Cardiac performance improved after phosphatemia normalization in all patients (cardiac index: 3.82 +/- 1.87 versus 4.52 +/- 1.83 1/min.m2; p < 0.01).

Conclusion: This study underlines the high incidence (28.8%) of hypophosphatemia in surgical intensive care patients and its association with a high mortality rate (30%). A short course of phosphotherapy improves cardiac index (+18%).