Value of the plasma protein and hemoglobin concentration in the diagnosis of pulmonary edema in scorpion sting patients

Objective: To investigate the value of measuring total plasma protein and hemoglobin concentrations for the diagnosis of pulmonary edema secondary to scorpion envenomation. Design and setting: Retrospective study over a 4-year period in the medical intensive care unit of a university hospital. Patients: 67 patients older than 3 years admitted in the intensive care unit for scorpion envenomation and stratified into two groups according to the presence of pulmonary edema assessed by a medical committee that took into account clinical, radiological, and blood gas data at admission and after treatment. Total plasma protein and hemoglobin concentrations were analyzed separately. Results: At admission all patients with and without pulmonary edema exhibited polypnea and tachycardia. The mean plasma protein and hemoglobin concentrations were higher in patients with pulmonary edema (74 +/- 6 and 14.2 +/- 2.0 g/dl, respectively) than in those without pulmonary edema (64 +/- 6 and 12.3 +/- 1.4 g/dl). After 24 h plasma protein and hemoglobin concentrations decreased in the pulmonary edema group (-11 and-1.9 g/dl) despite a negative fluid balance (-500 ml). A plasma protein concentration of 70 g/l or more predicted the presence of pulmonary edema with a sensitivity of 80% a specificity of 96%, a positive predictive value of 97%, and negative predictive value of 77%. Conclusions: In scorpion-envenomed patients with cardiorespiratory manifestations high plasma protein and hemoglobin concentrations suggest the presence of pulmonary edema.