The researchers said that patients who developed severe acute respiratory distress syndrome (ARDS), were treated with extracorporeal membrane oxygenation (ECMO).
ARDS is a lung condition that leads to respiratory failure due to the rapid accumulation of fluid in the lungs. ECMO is a type of life support that circulates blood through a system that adds oxygen.
The study showed that 68 patients with severe influenza-associated ARDS were treated with ECMO, including 53 with confirmed 2009 influenza A(H1N1).
An additional 133 patients with influenza A received mechanical ventilation, but not ECMO, in the same ICUs. The 68 patients who received ECMO had a median (midpoint) age of 34.4 years and half were men.
"Affected patients were often young adults, pregnant or postpartum, obese, had severe respiratory failure before ECMO, and received prolonged mechanical ventilation and ECMO support," said the authors.
The study showed that 54 of the 68 patients had survived and 14 had died. Six patients remained in ICU, including two who were still receiving ECMO. Sixteen patients were still hospitalized, but out of ICU, and 32 had been discharged from the hospital.
"Despite their illness severity and the prolonged use of life support, most of these patients survived," said the authors.
"This information should facilitate health care planning and clinical management for these complex patients during the ongoing pandemic," they added.
The study appears in Journal of American Medical Association (JAMA).