PURPOSE: Patients infected with H1N1 can rapidly develop severe respiratory failure or acute respiratory distress syndrome (ARDS) requiring mechanical ventilators (MV). Limited information is available about outcome.
METHODS: Retrospective observational study of all adults diagnosed with H1N1 causing ARDS was conducted after IRB approval. They were divided in 2 groups; standard care (SC, n=7, oseltamivir, conventional MV) and extraordinary care (EOC, n=10, SC plus Bi-Level MV, high frequency oscillator (HFO), inhaled NO and IV peramivir). Demographics data, P/F ratio, and outcome collected. Diagnosis established by polymerase chain reaction (rt-PCR) on nasopharyngeal swab or broncho alveolar lavage (BAL) samples. Simple frequency analysis was used to report the data in percentages and mean.
RESULTS: Seventeen (11 women) patients are included, mean age of 48 yrs and BMI of 42 (SD 15). Mean BMI of patients with SC was 33. EOC patients (N=10) had a mean BMI of 48. Diabetes was present in 8. Initial mean P/F ratio was 131; mean length of stay on ventilator was 16 days (range 3-42). Thirteen out of 17 (76%) patients survived. Six out of 7 (85%) with SC and 7 of 10 (70%) receiving EOC survived. One patient in SC was reintubated with delirium; he was made comfort care by family. Fifteen had BAL and 16 had nasopharyngeal rt-PCR performed; 13 and 9 were positive, respectively. Seven patients had negative nasopharyngeal but positive BAL; 5 (29%) had both tests positive; two had positive nasopharyngeal but negative BAL.
CONCLUSION: In our study, some trends are significant and clear. Over all survival was 76 % (13/17) in patient with H1N1 infection and ARDS. BMI > 40 (n= 8) and diabetes (n= 8) are associated with more severe disease, requiring EOC and have higher mortality. Nasopharyngeal rt-PCR can be inadequate for diagnosis of H1N1 influenza. BAL rt-PCR is helpful in confirmation in intubated patient.
CLINICAL IMPLICATIONS: The EOC utilizing HFOV, inhaled nitric oxide and peramivir can improve survival in patients with H1N1 and ARDS.
DISCLOSURE: Anthony Loschner, No Financial Disclosure Information; No Product/Research Disclosure Information