Severe acute respiratory distress syndrome complicating type A (H1N1) influenza treated with extracorporeal CO2 removal

BACKGROUND: The influenza pandemic of 2009 was reported to be frequently associated with pulmonary complications, including ARDS. We report the case of a morbidly obese, 37-year-old, AH1N1-infected woman, who was admitted to a regional hospital because of rapidly progressing respiratory failure. She was treated successfully with high frequency oscillatory ventilation (HFOV) and low-flow extracorporeal CO2 removal. CASE REPORT: The patient was admitted to a regional hospital because of severe viral infection, diabetes and hypertension that developed during pregnancy. On admission, she was deeply unconscious (GCS 5), hypotonic and anuric. Conventional ventilation, veno-venous haemofiltration, antibiotics and antiviral therapy (oseltamivir) did not improve the patient's condition, and she was transferred to a tertiary referral centre. Immediately before the transfer, she suffered two cardiac arrest episodes. They were successfully reversed. On admission, the patient was hypercapnic (PaCO2 150 mm Hg/20 kPa), acidotic (pH 6.92) and hyperkinetic (HR 120 min-1, CO 12.7 L min-1). Total lung compliance was 21 mL cm H2O-1, and SAP/DAP was 63/39 mm Hg). The PaO2/FIO2 index was 85. HFOV was instituted for 48 h, resulting in a marked improvement in gas exchange, however any manipulations caused immediate deterioration in the patient's condition. Extracorporeal CO2 removal was commenced and continued for 120 h, resulting in gradual improvement and eventual weaning from artificial ventilation after 17 days. Further treatment was complicated by septic shock due to Pseudomonas aeruginosa infection of the vagina, treated with piperacillin/tazobactam. The patient eventually recovered and returned to her regional hospital after 24 days. DISCUSSION: During the 2009 pandemic, a high number of pulmonary complications were observed all over the world. Viral infections are especially difficult to treat and the CESAR study indicated that the use of ECMO or extracorporeal CO2 removal devices may result in a lower mortality when compared with standard therapy. We conclude that the use of a simple CO2 removal device can be beneficial in complicated cases of AH1N1 influenza.