Pulmonary Disorders I

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.