Difficult to wean: Think of the diaphragm

A 65-year-old woman, treated for non-ST segment elevation myocardial infarction and unexplained type 2 respiratory failure, was referred to our hospital in view of difficulty in weaning off the ventilator. She was evaluated in detail for persistent hypercapnia. Ultrasound of the diaphragm showed minimal excursion of diaphragm while she was off the ventilator and fluoroscopy confirmed bilateral diaphragmatic palsy. As extensive radiological, immunological and microbiological workup ruled out other possible aetiologies, a diagnosis of idiopathic Bell's palsy of the diaphragm was made. She was treated with valacyclovir and steroids after which she gradually recovered and was weaned off the ventilator.