Clinical Management of Pandemic 2009 Influenza A(H1N1) Infection

Abstract

Antiviral therapy and vaccination are important strategies for controlling pandemic 2009 influenza A(H1N1) but efficacy depends on the timing of administration and is often limited by supply shortage. Patients with dyspnea, tachypnea, evidence of hypoxemia, and pulmonary infiltrates on chest radiograph should be hospitalized. Patients with severe illness or underlying medical conditions that increase the risk of more severe disease should be treated with oseltamivir or zanamivir as soon as possible, without waiting for the results of laboratory tests. Lung-protective ventilation strategy with a low tidal volume and adequate pressure, in addition to a conservative fluid management approach, is recommended when treating adult patients with ARDS. Extracorporeal membrane oxygenation has emerged as an important rescue therapy for critically ill patients. Use of systemic steroids was associated with delayed viral clearance in severe acute respiratory syndrome and H3N2 infection. Low-dose corticosteroids may be considered in the treatment of refractory septic shock. Passive immunotherapy in the form of convalescent plasma or hyperimmune globulin may be explored as rescue therapy. More data are needed to explore the potential role of IV gamma globulin and other drugs with immunomodulating properties, such as statins, gemfibrozil, and N-acetyl-cysteine. Health-care workers must apply strict standard and droplet precautions when dealing with suspected and confirmed case and upgrade to airborne precautions when performing aerosol-generating procedures. Nonpharmacologic measures, such as early case isolation, household quarantine, school/workplace closure, good community hygiene, and restrictions on travel are useful measures in controlling an influenza pandemic at its early phase.

IL-17 response mediates acute lung injury induced by the 2009 Pandemic Influenza A (H1N1) Virus

“…The commonly applied therapeutics included antiviral (mostly Tamiflu/ Oseltamivir) and corticosteroid treatments [18]. While controversy regarding the drug efficacy of corticosteroids in the treatment of acute respiratory distress syndrome patients infected with 2009 pandemic H1N1 has been reported [19,20], the effects of Tamiflu treatment at an early stage of disease-onset are well-established [21][22][23]. Using our newly established mouse model, infected with the 2009 pandemic BJ501 strain, we tested the drug efficacy of Oseltamivir.…”

Impact of Humidification and Nebulization During Expiratory Limb Protection: An Experimental Bench Study

“…Those changes in ventilator mechanics might have dramatic consequences during lungprotective ventilation, which is mandatory in severe ARDS, as encountered during the SARS outbreak or the H1N1 flu pandemic. 5,[25][26][27][28][29][30] In a recent clinical trial of antibiotics nebulization, obstruction of the expiratory filter occurred in 3 patients of a 20-patient cohort, and caused cardiac arrest in 1 patient. 21 Our results suggest that the increase in expiratory resistance is due mainly to filter saturation by water condensates.…”

Fully Bayesian Experimental Design for Pharmacokinetic Studies

“…ECMO is used as a final resort in critically ill patients with potentially reversible respiratory failure to temporarily support the heart and/or lungs. In 2009, during the worldwide H1N1 pandemic, ECMO was a vital treatment modality for H1N1 patients requiring advanced ventilatory support [19][20][21][22] and has a reported survival rate of approximately 50% when used in critically ill adults with respiratory failure [23]. Despite the major benefits that ECMO can afford, it can also induce a wide variety of PK changes in critically ill patients that are not fully understood and can lead to therapeutic failure or toxicity.…”