Systolic pressure variation in hemodynamic monitoring after severe blast injury

Fluid management in patients following blast injury is a major challenge. Fluid overload can exacerbate pulmonary dysfunction, whereas suboptimal resuscitation may exacerbate tissue damage. In three patients, we compared three methods of assessing volume status: central venous (CVP) and pulmonary artery occlusion (PAOP) pressures, left ventricular end-diastolic area (LVEDA) as measured by transesophageal echocardiography, and systolic pressure variation (SPV) of arterial blood pressure. All three patients were mechanically ventilated with high airway pressures (positive end-expiratory pressure 13 to 15 cm H2O, pressure control ventilation of 25 to 34 cm H2O, and I:E 2:1). Central venous pressure and PAOP were elevated in two of the patients (CVP 14 and 18 mmHg, PAOP 25 and 17 mmHg), and were within normal limits in the third (CVP 5 mmHg, PAOP 6 mmHg). Transesophageal echocardiography was performed in two patients and suggested a diagnosis of hypovolemia (LVEDA 2.3 and 2.7 cm2, shortening fraction 52% and 40%). Systolic pressure variation was elevated in all three patients (15 mmHg, 15 mmHg, and 20 mmHg), with very prominent dDown (23, 40, and 30 mmHg) and negative dUp components, thus corroborating the diagnosis of hypovolemia. Thus, in patients who are mechanically ventilated with high airway pressures, SPV may be a helpful tool in the diagnosis of hypovolemia.