Serotonin and pulmonary hypertension in human septic ARDS.

Pulmonary hypertension gives an indication of poor prognosis in adult respiratory distress syndrome (ARDS) complicating sepsis. In this study, we examined the role of the platelet and the vasoactive amine, serontonin, in pulmonary hypertension accompanying septic ARDS. The lack of any significant difference in platelet number (delta + 3.9 +/- 8.4, X 10(3)/mm3) or serum serotonin (delta - 0.03 +/- 0.06 nm/mm3) across the pulmonary vascular bed (pulmonary artery minus pulmonary vein), would suggest that platelet sequestration and/or release of serotonin is not a major factor in septic ARDS. However, we did note a direct positive relationship between serum serotonin (Ss) and the pulmonary artery diastolic minus pulmonary capillary wedge pressure (PAd-PCWP) gradient (r = 0.64, p < 0.01) implying that serum serotonin may be related to pulmonary hypertension in septic ARDS.