IntroductionPatients with influenza A (H1N1)v infection have developed rapidly progressive lower respiratory tract disease resulting in respiratory failure. We describe the clinical and epidemiologic characteristics of the first 32 persons reported to be admitted to the intensive care unit (ICU) due to influenza A (H1N1)v infection in Spain.MethodsWe used medical chart reviews to collect data on ICU adult patients reported in a standardized form. Influenza A (H1N1)v infection was confirmed in specimens using real-time reverse transcriptase-polymerase-chain-reaction (RT PCR) assay.ResultsIllness onset of the 32 patients occurred between 23 June and 31 July, 2009. The median age was 36 years (IQR = 31 - 52). Ten (31.2%) were obese, 2 (6.3%) pregnant and 16 (50%) had pre-existing medical complications. Twenty-nine (90.6%) had primary viral pneumonitis, 2 (6.3%) exacerbation of structural respiratory disease and 1 (3.1%) secondary bacterial pneumonia. Twenty-four patients (75.0%) developed multiorgan dysfunction, 7 (21.9%) received renal replacement techniques and 24 (75.0%) required mechanical ventilation. Six patients died within 28 days, with two additional late deaths. Oseltamivir administration delay ranged from 2 to 8 days after illness onset, 31.2% received high-dose (300 mg/day), and treatment duration ranged from 5 to 10 days (mean 8.0 ± 3.3).ConclusionsOver a 5-week period, influenza A (H1N1)v infection led to ICU admission in 32 adult patients, with frequently observed severe hypoxemia and a relatively high case-fatality rate. Clinicians should be aware of pulmonary complications of influenza A (H1N1)v infection, particularly in pregnant and young obese but previously healthy persons.

The oxygen therapy is an universal treatment in the hospital setting, especially in the critical care units. The purpose of this therapy is to avoid hypoxemia and to ensure an adequate supply of oxygen to the tissues. But often we overlook the potential adverse effects of oxygen therapy. Oxygen produces lung damage and induces apoptosis and cell death creating an imbalance between the production of reactive species of oxygen and the antioxidant mechanisms. The oxygen therapy inhibits systemic adaptive changes induced by hypoxia, disrupting compensatory mechanisms and causing deleterious effects. We are faced with a challenge in order to treat patients with respiratory failure, counterbalancing hypoxia with hyperoxia-induced damage and introducing therapy lines that are innovative but not risk-free as permissive hypoxemia. Currently many questions remain unresolved and there are not enough clinical studies that validate the therapeutic optimal oxygenation ranges. These ranges may differ depending on each patient and the underlying disease.

No abstract

No abstract

No abstract