Pulmonary Disorders I
| d. | Despite the paucity of data for inhaled epoprostenol, it is commonly used in the ICU for ARDS as a |
|---|
bridge to more invasive management strategies (i.e., ECMO) and/or as salvage therapy. Although the
optimal dosing regimen remains unknown, the most commonly used doses include a weight-based
strategy (typically 10–50 ng/kg/minute titrated to effect) (J Pharm Pract 2019;32:347-60). A small
prospective study evaluated a dose-response relationship of weight-based inhaled epoprostenol in
patients with ARDS, titrating from 0 to 50 ng/kg/minute by increments of 10 ng/kg/minute every
30 minutes (Chest 2000;117:819-27). A significant increase in the absolute median Pao2/Fio2 was
observed with the 50 ng/kg/minute weight-based dose compared with baseline (202.2 vs. 187.2
mm Hg, respectively; p<0.008). However, no significant difference was observed with the median
Pao2/Fio2 (183.2 mm Hg) associated with the 10 ng/kg/minute regimen compared with baseline.
Furthermore, no statistically significant difference was found between the 10 and 50 ng/kg/minute
weight-based regimens regarding oxygenation indices. A major caveat of this study was small
sample size (n=9), and the patient population was not reflective of contemporary clinical use of
inhaled epoprostenol in moderate to severe ARDS, given that only three patients had a baseline
Pao2/Fio2 less than 150 mm Hg. Recently, one study observed a similar effect on oxygenation using
fixed-dose inhaled epoprostenol without titration compared with inhaled nitric oxide (J Intensive
One study directly compared weight-based and fixed-dose inhaled epoprostenol in ARDS patients
to 4 hours after inhaled epoprostenol initiation was significantly higher in the the fixed-dose group
compared with the weight-based dosing approach (81.1 ± 106.0 vs. 41.0 ± 72.5 mm Hg, respectively;
p=0.0015). Also, responder rates at 4 hours after inhaled epoprostenol initiation was significantly
higher with fixed-dosing over weight-based dosing (69.9% vs. 30.1%; p=0.02). Clinical outcomes
were comparable between the two dosing groups.
Patient Cases
A 56-year-old man is admitted to the ICU with ARDS after experiencing increasing dyspnea during the past
24 hours. His medical history is significant for alcoholism and hypertension. Results of the initial arterial
blood gas are as follows: pH 7.24, Paco2 58 mm Hg, HCO3 24 mEq/L, Pao2 50 mm Hg, and Sao2 84% while
receiving MV AC mode with Fio2 100%. Chest radiography reveals diffuse bilateral infiltrates. The patient
has blood pressure 120/40 mm Hg (MAP 67 mm Hg), heart rate 142 beats/minute, and CVP 8 mm Hg while
receiving a norepinephrine (10 mcg/minute) infusion after intravenous fluid resuscitation. Norepinephrine
has now been weaned off while maintaining a MAP of 67 mm Hg. Ceftriaxone 1 g intravenously every 24
hours and levofloxacin 750 mg intravenously every 24 hours have been initiated for community-acquired
pneumonia. Which is the best therapeutic plan for the patient’s ARDS?
kg of ideal body weight; prone positioning; and sedative administration to target deep sedation and
cisatracurium infusion.
body weight; supine positioning; and sedative administration to target deep sedation and cisatracurium
infusion.
weight; supine positioning; and sedative administration to target deep sedation.
a MAP greater than 65 mm Hg; low tidal volume strategy of 4–8 mL/kg of ideal body weight; prone
positioning; and sedative administration to target deep sedation and cisatracurium infusion.