Sedation and analgesia usage in severe pandemic H1N1 (2009) infection: a comparison to respiratory failure secondary to other infectious pneumonias.

BACKGROUND: During the 2009 H1N1 pandemic (pH1N1), patients requiring mechanical ventilation for respiratory failure received high doses of sedation and analgesia.

OBJECTIVE: To examine sedation and analgesia use among patients with respiratory failure due to severe pH1N1 infection compared to other infectious pneumonias.

METHODS: In this observational cohort study of intensive care unit (ICU) patients with respiratory failure, we compared doses of sedatives and analgesics administered to patients with pH1N1, non-pH1N1 viral pneumonia, and adult respiratory distress syndrome (ARDS) secondary to bacterial pneumonia, on days 1, 3, 7, 14, and 28 of ICU admission. Cumulative drug use, daily drug use, and weight-adjusted medication doses were examined.

RESULTS: The study population consisted of 37 patients with pH1N1 infection, 22 patients with non-pH1N1 viral pneumonia, and 46 patients with ARDS secondary to bacterial pneumonia. To achieve similar levels of sedation using the Richmond Agitation Sedation Scale, patients with pH1N1 were administered the highest cumulative median doses of fentanyl (11,230 μg; interquartile range [IQR] 3240-21,000), compared to 2400 μg (IQR 130-7130) in viral pneumonia and 2880 μg (IQR 600-6950) in ARDS (p < 0.001). Patients with pH1N1 were also administered the highest cumulative median doses of midazolam at 820 mg (IQR 330-1160), compared to 160 mg (IQR 20-390) in viral pneumonia and 160 mg (IQR 20-480 mg) in ARDS (p < 0.001). The pH1N1 group received the highest median daily fentanyl and midazolam doses on all study days. The pH1N1 group did not differ significantly in cumulative propofol dose compared with the other 2 study groups.

CONCLUSIONS: Sedative and analgesic use may be uniquely higher in critically ill patients with pH1N1 infection compared to patients with other infectious pneumonias. This finding may be important for resource planning in future pandemics. Further study is required to explore the underlying mechanisms for potentially higher sedative and analgesic requirements in this patient population.