Outcome of varicella pneumonitis in immunocompetent adults requiring treatment in a high dependency unit

Objectives: The incidence of varicella infection is increasing in adults, w here primary pneumonitis; is the main complication. Little information exis ts concerning treatment of those patients who require admission to a high d ependency unit (HDU) facility. A study was performed to examine the risk fa ctors for developing varicella pneumonitis (VP), to document disease progre ssion and assess prognosis for patients with VP requiring HDU admission. Methods: A 10-year retrospective casenote review of patients admitted to th e Regional Infectious Diseases Unit HDU. Varicella pneumonitis (VP) was def ined as diffuse nodular shadowing on a chest X-ray (CXR) of a patient with a classical chickenpox rash. Severe pneumonitis was defined as an hypoxaemi a index (pO2 in mmHG/FiO(2)) of less than 150 at any time during hospital s tay. All patients were treated with intravenous acyclovir at a dose of 10 m g/kg. Results: A total of 33 patients were admitted to the HDU with VP over the s tudy period, 30 were included in the study. Annual admission rates remained constant. Most patients (76.7%) had at least one recognised risk factor fo r severe VP: smoking 18/30, pregnancy 9/30, chronic lung disease 7/30. Twel ve (40%) patients had severe VP, eight (26.7%) required assisted ventilatio n. The presence of greater than one risk factor (p < 0.02) was associated w ith progression to severe VP. There was one death: a 63-year-old man with a long history of chronic airflow limitation whose treatment had included do micillary long-term oxygen therapy. Nine (30%) patients developed secondary bacterial pneumonia. all recovered with appropriate antibiotic treatment. The period of stay in HDU for the majority of patients was short (mean 4.5 days). Conclusions: The prognosis for severe adult VP with current available treat ment is good. The only predictor on admission for severe VP is the presence of more than one recognised risk factor for developing VP. (C) 2001 The Br itish Infection Society.