Critical Care Medicine-Pulmonary Disorders>>>>>Pulmonary Infections
Question 4#

A 25-year-old man with a history of mild intermittent asthma is admitted to the ICU with rapidly progressive hypoxemic respiratory failure following 4 days of fevers, myalgias, and cough at home. He is intubated and mechanically ventilated on volume assist-control with a tidal volume of 6 mL/kg, respiratory rate 14 breaths per minute, FiO2 0.8, and PEEP of 10 cm H2O. His arterial blood gas on these settings is:

His chest radiograph demonstrates diffuse bilateral patchy opacities, and his rapid influenza testing is positive for influenza A.

Which of the following statements is MOST accurate regarding diagnosis and treatment for this patient?

A. With his history of asthma, he should receive methylprednisolone at 1 mg/kg daily
B. Antibacterial coverage can be discontinued as he is positive for influenza A
C. Treatment with oseltamivir 75 mg twice daily is not indicated as he is 4 days into his illness
D. If a sputum culture cannot be obtained, a diagnostic bronchoscopy with bronchioalveolar lavage is indicated
E. This patient does not meet criteria for acute respiratory distress syndrome (ARDS) and does not need low tidal volume ventilation

Correct Answer is D

Comment:

Correct Answer: D

This patient is presenting with respiratory failure secondary to influenza A infection. He meets clinical criteria for ARDS, which include acute onset of bilateral infiltrates with associated hypoxemia in the absence of evidence of explanatory cardiogenic pulmonary edema (answer E is incorrect). Mainstays of treatment for severe influenza pneumonia include antiviral therapy with oseltamivir (answer C is incorrect) and empiric treatment of possible secondary bacterial infection (answer B is incorrect). Common bacterial pathogens that coinfect with influenza include S. pneumoniae, Staphylococcus aureus, and Haemophilus influenzae, and coverage should be targeted to these organisms. Treatment with steroids in patients with influenza infection is associated with an increased risk of mortality, and although these data are observational, the consensus is that steroids should be avoided if possible (answer A is incorrect).

References:

  1. ARDS Definition Task Force. Acute respiratory distress syndrome: the berlin definition. JAMA. 2012;307(23):2526-2533.
  2. Mandell LA, Wunderink RG, Anzueto A, et al. Infectious diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis. 2007;44(suppl 2):S27-S72.
  3. Rodrigo C, Leonardi-Bee J, Nguyen-Van-Tam J, Lim WS. Corticosteroids as adjunctive therapy in the treatment of inluenza. Cochrane Database Syst Rev. 2016;3:CD010406.