Echoing results presented previously, two new papers published online today by the Journal of the American Medical Assn. show that patients hospitalized with pandemic H1N1 influenza last spring often deteriorated rapidly and had to spend long periods in the intensive care unit before they recovered. Many of them did not recover and died.
Australian and U.S. researchers reported last week that about a quarter of patients hospitalized with confirmed swine flu were admitted to intensive care units and that about 16% died. Now Canadian and Mexican researchers are reporting similar findings, although the death rate in Mexico--which was the first to bear the brunt of the outbreak--was more than double that seen elsewhere.
Dr. Anand Kumar of St. Boniface Hospital in Winnipeg, Manitoba, and his colleagues studied 168 critically ill flu patients in adult and pediatric ICUs at 38 Canadian hospitals. They reported that the severe illnesses occurred primarily in those between age 10 and 60. Seasonal flu affects a much higher proportion of the elderly. Most of the critically ill patients had suffered from flu symptoms for three to four days before entering the hospital. Once there, their conditions deteriorated rapidly and they entered ICUs within another day or two. The average stay in the ICU was 12 days and most required mechanical ventilation and a host of other treatments. Twenty-four of the patients died within the first 29 days and five more within 90 days. Overall, 67% of the patients were female and 30% were children.
Dr. Guillermo Dominguez-Cherit of Instituto Nacional de Ciencias Medicas y Nutricion "Salvado Zubiran" in Mexico City and his colleagues reported on 899 patients who were admitted to six Mexico City hospitals last spring with confirmed or probable swine flu. Of those, 58, with a median age of 44, became critically ill and 24 (41.4%) died within 60 days. As in Canada, many of the critically ill patients were obese, but their death rate was not higher than that of other patients. Of the 58, 45 patients were treated with antiviral agents such as Tamiflu and 54 required mechanical ventilation.
The fact that the disease progresses so rapidly means that hospitals need to be prepared to treat these patients 24/7, wrote Dr. Douglas B. White of the University of Pittsburgh, in an editorial accompanying the reports. He noted that even though the virulence of the virus in Canada and Mexico was relatively mild, the critical care cases consumed large amounts of medical resources. If the virulence should increase this winter, he added, hospitals across the United States may find their resources excessively strained and may have to perform triage, meaning some patients may not be adequately treated.
-- Thomas H. Maugh II