Severe Cases of Pandemic H1N1 Pneumonia and Respiratory Failure Requiring Intensive Care

Abstract

Background: The objective of our study is to analyze the clinical data of patients with pandemic H1N1 2009 infection admitted to the intensive care unit (ICU) and to report key features observed among these patients. Methods: A total of 18 patients were admitted to our ICU between July and November 2009, with a primary diagnosis of influenza. Clinical data were analyzed to identify potential risk factors and characteristics thought to affect outcomes. Results: Our patients were between ages 23 and 62 (mean 41). In all, 10 were obese. Two had no other comorbid conditions and 6 had obesity as their only comorbid condition. The most common symptoms were fever, shortness of breath, and cough. Laboratory data were notable for elevated creatine kinase levels, transaminitis, and lack of leukocytosis. The rapid influenza detection test (RIDT) had a 76% false negative result. Patients with a negative RIDT had their infection confirmed with real-time reverse transcriptase polymerase chain reaction (rRT-PCR). A total of 12 patients required invasive mechanical ventilation, with over half of whom responded only to nonconventional modes of ventilation. Most patients received high-dose (150 mg twice daily) oseltamivir. In all, 3 patients died and 11 were discharged without any long-term sequalae. Conclusions: Unlike seasonal influenza, our patients were not in the extremes of age. Most were obese and presented with severe respiratory distress and hypoxia in the summer months. A negative RIDT did not exclude pandemic H1N1 2009. Using a higher dose of oseltamivir and nonconventional modes of ventilation may have improved the outcome in our subset of patients. Hence, patients with a high clinical suspicion of severe influenza infection should be treated early and aggressively, even before confirmatory results are available.

Chest Radiological Findings of Patients With Severe H1N1 Pneumonia Requiring Intensive Care

“…Most patients arrived to the emergency department with tachycardia (72%) and hypoxia (72%), with arterial oxygen saturation less than 93% on room air. 16 Twelve (67%) patients had a ratio of PaO 2 to fraction of inspired oxygen (PaO 2 -FiO 2 ) of less than 200, and these patients required intubation for respiratory failure. The average number of days patients remained mechanically ventilated was 15 days, and the average ICU length of stay was 14 days.…”

Influenza virus infections among patients attending emergency department according to main reason to presenting to ED: A 3-year prospective observational study during seasonal epidemic periods

“…The frequency of lung damage is higher in patients with underlying cardiac or pulmonary diseases [ 21 , 22 ] and Influenza has been associated with increased mortality [ 23 ]. In the present study, 58% of the patients had at least one underlying condition for severe influenza [ 18 ], and 59% of patients had at least one severity criteria [ 19 ]. Respiratory distress was the main symptom, with up to 45% of patients exhibiting signs of clinically significant respiratory distress.…”

“…In accordance with the inclusion criteria, three groups were defined on the basis of the initial reason for presentation in the ED. Groups were defined by ED physician during ED stay: (1) Patients presenting with acute respiratory symptoms suggesting CAP (CAP group); (2) Patients presenting with severe acute symptoms (SAS group) [ 18 ]: polypnea, cyanosis, oxygen saturation Spa02 <95%, pneumonia, wheeze, tachycardia, hypotension, areas of mottled skin, malaise, change in mental status, and oliguria; and (3) patients with symptoms suggesting Influenza virus infection (fever and cough or myalgias or rhinorrhea) and with underlying conditions for severe influenza (PSSI group): age ≥65 years, asthma, bronchopulmonary dysplasia, cystic fibrosis, chronic respiratory failure, cardiac failure, cardiac valvulopathy, congenital heart disease, cardiovascular disease, renal failure, nephrotic syndrome, sickle-cell anemia, hepatic failure, diabetes, systemic corticosteroid therapy, leukemia or lymphoma, immunosuppression, cancer, HIV infection, CD4 lymphocytes count, obesity, and pregnancy [ 19 ]. Patients in the SAS group were classified into four subgroups on the basis of their main reason for visiting the ED: a) respiratory failure (RF); b) hemodynamic failure (HF); c) cardiac failure (CF); and d) miscellaneous (M).…”