Use of therapeutic plasma exchange as a rescue therapy in 2009 pH1N1 influenza A--an associated respiratory failure and hemodynamic shock

Abstract

Objective: Acute pneumonitis with acute lung injury is a cause of significant mortality related to the 2009 pH1N1 influenza A virus. Widespread lung inflammation and increased pulmonary vascular permeability has been noted on autopsy. Also, many of these patients present with significant hemodynamic compromise suggesting systemic cytokine release. Therefore, attenuating circulating cytokines, and other mediators, by blood purification techniques is a theoretically attractive strategy. We report the use therapeutic plasma exchange in three children with 2009 H1N1 related acute lung injury with severe hemodynamic compromise that had failed conventional therapeutic interventions.

Design: Case series.

Setting: Pediatric intensive care unit in a university children's hospital.

Patients: Three children, aged 8, 11, and 17 yrs, with acute respiratory distress syndrome and hemodynamic compromise related to the 2009 pH1N1 influenza A virus documented by polymerase chair reaction. All patients were on mechanical ventilation and inhaled nitric oxide, and one patient was on extracorporeal membrane oxygenation. Therapeutic plasma exchange was used as a rescue strategy.

Interventions: Each patient received three exchanges of 35-40 mL/kg on consecutive days.

Measurements: All three patients had dramatic reduction in pediatric logistic organ dysfunction scores, oxygen requirements, and vasopressor requirements after two exchanges. All survived with good functional recovery.

Main results: In this small series of patients with H1N1/acute respiratory distress syndrome and hemodynamic compromise, therapeutic plasma exchange appeared to benefit as a method of mitigating the associated cytokine storm. The procedure was well tolerated with no reported side effects. All three patients survived, defying the predicted mortality. Because these procedures used the filtration exchange method, it was performed in a timely fashion by intensive care unit personnel and on equipment already available in the intensive care unit for renal support.

Conclusions: This very limited case series suggest there may be a role for therapeutic plasma exchange as a rescue therapy in severe shock and acute lung injury related to pH1N1 that has not responded to traditional therapy.

Figure 1.

Pediatric Logistic Organ Dysfunction score for each patient. All patients received therapeutic plasma exchange on days 1–3. There is a significant reduction in Pediatric Logistic Organ Dysfunction scoring (p = .001 based on paired t test).