Q: What is the best time to initiate prone positioning in ARDS to get maximum benefit?

A) First 36 hours
B) Between 48 and 72 hours
C) When all rescue therapy fails in first week
D) One FiO2 is down to 80%
E) Once PEEP is down to at least 14


Answer: A

As per latest literature, we have learned that prone positioning  is most efficacious if initiated early. If patient get relatively stabilized and if it is evident from clinical picture that respiratory failure is severe, it would not be bad to keep low threshold to initiate prone positioning. Lung recruitment is most effective in early phase of ARDS. 


References: 

1. Mancebo J, Fernández R, Blanch L, et al. A multicenter trial of prolonged prone ventilation in severe acute respiratory distress syndrome. Am J Respir Crit Care Med 2006; 173:1233 

2.  Guérin C, Reignier J, Richard JC, et al. Prone positioning in severe acute respiratory distress syndrome. N Engl J Med 2013; 368:2159