Influenza A/H5N1 infection: other treatment options and issues

Abstract

Antiviral therapy and vaccination are important strategies for the control of human influenza/H5N1 disease, but the efficacy of these modalities is limited by timing of administration and shortage of supply. Lung protective ventilation strategy with a low tidal volume and low pressure, in addition to a conservative fluid management approach, is recommended when treating patients with ARDS. Low-dose steroids may be considered in the treatment of refractory septic shock. Non-invasive positive pressure ventilation (NPPV) may play a limited supportive role for early ARDS/acute lung injury, but it is contra-indicated in critically ill patients with multi-organ failure and haemodynamic instability. NPPV and oxygen therapy should be applied in healthcare facilities with good ventilation and respiratory protection as substantial exposure to exhaled air occurs within a 0.5 m and 0.4 m radius of patients receiving NPPV and oxygen via a simple mask, respectively. Intravenous gammaglobulin should be used with caution for treatment of reactive haemo-phagocytosis due to its thrombogenic effects, whereas the role of etoposide needs evaluation with animal models. Passive immunotherapy in the form of convalescent plasma may be useful as rescue therapy. More data are needed to explore the potential role of other drugs with immuno-modulating properties such as statins. Healthcare workers currently must apply strict standards, contact and droplet precautions when dealing with suspected cases, and upgrade to airborne precautions when performing aerosol-generating procedures. Non-pharmacological measures such as early case isolation, household quarantine, school/workplace closure, good community hygiene and restrictions on travel are useful measures in controlling a pandemic.