A 45-year-old male with past medical history of COPD is admitted for acute hypoxemic respiratory failure secondary to influenza H1N1. He is intubated for 7 days. On hospital day 7, his P/F ratio has improved to 220 and the patient’s chest x-ray looks improved. He fails spontaneous breathing trial for two consecutive days secondary to low tidal volumes. He has poor cough reflex and was given 5 days of steroids for his acute illness.
Which electrolyte is most likely to be deficient in this patient?
A. Serum phosphorusCorrect Answer: A
Low serum phosphorus has been strongly associated with diaphragmatic weakness. Since the duration of steroid therapy was short, the probability of steroid induced myopathy is low.
Reference: