Objective: Evaluation of right ventricular (RV) performance in patients presenting with pulmonary edema following scorpion envenomation.
Design: Cohort study.
Setting: Medical intensive care unit of a teaching hospital.
Patients: Eight consecutive adult patients stung by yellow scorpion Androctonus australis and presenting with pulmonary edema at hospital admission.
Interventions: In all patients, standard hemodynamic parameters and RV volumes were measured using a pulmonary artery catheter equipped with a rapid responding thermistor enabling measurement of RV ejection fraction (RVEF).
Measurements: Hemodynamic evaluation was performed at the time of hospital admission prior to any therapeutic intervention and just before the removal of the pulmonary catheter (2.3 +/- 0.5 days after admission) in the surviving patients (n = 7).
Results: All patients had a decreased RVEF (24 +/- 7%) and cardiac index (2.44 +/- 0.5 L/min/m2) and increased pulmonary artery occlusion pressure (23 +/- 6 mm Hg). Right ventricular end-systolic pressure/volume ratio was decreased (.56 +/- .19 mm Hg/mL/m2), suggesting an altered RV contractility. Follow-up evaluation performed in survivors, without any inotropic support, showed hemodynamic changes reflecting a trend toward full recovery. Right ventricular ejection fraction and cardiac index improved markedly (from 24 +/- 7% to 39 +/- 10% and from 2.44 +/- 0.5 to 4 +/- .3 L/min/m2, respectively). Pulmonary artery occlusion pressure, peak systolic pulmonary artery pressure, and mean pulmonary artery pressure decreased significantly from baseline values (12 +/- 3 mm Hg, 29 +/- 5 mm Hg, and 20 +/- 4 mm Hg, respectively). Right ventricular end systolic pressure/volume ratio remained almost constant, suggesting that afterload enhancement accounted predominantly for RVEF improvement.
Conclusion: These data show that RV function impairment is associated with left ventricular dysfunction, suggesting similarities between left ventricular and RV alterations following severe scorpion envenomation providing further arguments to the hypothesis of scorpionic myocarditis.