CONTINUOUS ARTERIOVENOUS HEMOFILTRATION COUNTERCURRENT DIALYSIS (CAVH-D) IN ACUTE RESPIRATORY-FAILURE (ARDS)

The balance between intravascular volume, oxygen transport, and arterial oxygenation is delicate in patients with adult respiratory distress syndrome (ARDS). Recently, we used continuous arteriovenous countercurrent hemodialysis (CAVH-D) in 14 nonoliguric patients who had severe ARDS. The cause of the ARDS was pancreatitis in 1 patient, trauma in 10 patients, and postoperative in 4 patients. All patients were edematous, in marked positive fluid balance but not intravascularly overloaded before institution of CAVH-D. Transfemoral CAVH-D was instituted and managed by the SICU staff. Patients underwent CAVH-D for a mean of 65.2 hours (range, 12-140 hours) and cleared a mean of 480 mL/h of filtrate. The only complication was one patient who bled from a loose tubing connection. Three patients were grossly unstable when CAVH-D was begun. Their mean cardiac index (CI) was 2.3 L/min/m2 despite maximal inotropes. Their CAVH-D filters cleared a mean of 600 mL/h, but they required constant fluid resuscitation and died of cardiogenic shock and ARDS within 3 days. The other 11 patients had significant improvement in their respiratory function. Mean FI0(2) was weaned from 0.73 to 0.45 (p < 0.005) and PEEP from 14.3 cm to 8.9 cm (p < 0.005). Peak airway pressures fell from a mean of 60 mm Hg to 45 mm Hg (p < 0.01). There was no significant change in CI or wedge pressure, but oxygen consumption rose from a mean of 279 to 409 mL/m (p < 0.05). The technique of CAVH-D offers an alternative to patients with ARDS who do not have large on-going fluid requirements. It is safe, can be managed by the surgical staff, and is associated with a significant improvement in respiratory variables without requiring a drop in filling pressures that might potentially compromise oxygen transport.