A pregnant woman with acute cardiorespiratory failure: dengue myocarditis

In April, 2014, a 29-year-old Vietnamese woman, 31 weeks into her fourth pregnancy, presented to a clinic in Ho Chi Minh City with a 2 day history of fever, dry cough, chest pain, and shortness of breath. She had a history of partial thyroidectomy for hyperthyroidism in 2012, and had had three miscarriages. She took 150 μg thyroxine daily and was a non-smoker. She was initially treated for presumed pneumonia with imipenem. However, her respiratory function deteriorated overnight and she was transferred to the intensive care unit (ICU) at our hospital. On admission she was febrile (38°C), tachycardic (pulse 115 beats per min), and tachypnoeic (respiratory rate 28 breaths per min), with an SpO2 of 94% on 5 L oxygen. Heart sounds were normal but she had bibasal crackles on chest auscultation. Apart from a gravid uterus, abdominal examination was normal. Chest radiograph showed bilateral infi ltrates suggesting pulmonary oedema (appendix). Haemoglobin was 92 g/L, haematocrit 29·2%, total white cell count 8·5 × 109/L, (neutrophil count 7·53 × 109/L and lymphocyte count 0·4 × 10/L), with a platelet count of 134 × 109/L; INR was 1. Urea, electrolytes, liver transaminases, and procalcitonin were normal. Arterial blood gas analysis showed pH 7·49, PaO2 69 mm Hg, PaCO2 30·9 mm Hg, HCO3 23·7 mmol/L, and lactate 1·2 mmol/L. We started oseltamivir and continued imipenem and maintenance fl uids. Her respiratory function deteriorated further (respiratory rate 35 breaths per min, SpO2 85% on 15 L oxygen) so we started non-invasive ventilation with bilevel positive airway pressure (BiPAP) and added vancomycin and azithromycin. ECG showed inverted T waves in the inferior leads (appendix), and troponin I was raised (1·1 μg/L; normal