cause acute respiratory failure in younger people , '' says Dr. Neil Schachter , the medical director of the respiratory care department at Mount Sinai Medical Center , in New York City , and the author of The Good Doctor 's Guide to Colds and Flu . The analysis of cases in Australia and New Zealand looked at people who developed severe acute respiratory distress syndrome -LRB- a condition in which the lungs fill with fluid -RRB- and were put on a life-support system known as extracorporeal membrane oxygenation -LRB- ECMO -RRB- . This artificial heart and lung machine system , which puts oxygen into the blood and then carries this blood to the body tissues , is considered risky and expensive ; as a result , it is not readily available in every hospital . The mortality rate was 21 percent for these patients , although it may have been higher without this treatment , the authors say . Health.com : 8 ways swine flu is changing society `` These studies provide important signals about what clinicians and hospitals may confront in the coming months , '' Dr. Douglas B. White , and Dr. Derek C. Angus , of
-LRB- Health.com -RRB- -- An analysis of the sickest swine flu patients in Australia , Canada , Mexico , and New Zealand suggests that relatively healthy adolescents and young adults are among the most likely to get very sick after an H1N1 infection , a pattern similar to that seen in the 1918 influenza pandemic . The most important message is that children should get the H1N1 vaccination , Dr. Neil Schachter said . Almost all critically ill patients in the studies were sick for only a few days before rapidly progressing to more severe symptoms and respiratory failure , which required treatment with a breathing machine , according to three studies published in the Journal of the American Medical Association . The mortality rate ranged from 14.3 percent to 41.4 percent , depending on the country . The findings may help shine some light on what the 2009 H1N1 flu season may bring , and who may be hit the hardest by the swine flu during the next few months . `` These studies are telling us that young people are at risk for bad complications of H1N1 and under usual circumstances , -LSB- seasonal -RSB- flu does not