Pain, Agitation/Sedation, Delirium, Immobility, Sleep Disruption, and Neuromuscular Blockade

in 2016. Surveys have reported a dramatic decrease in the use of NMBAs during the past 20 years, from

practice may be secondary to a better understanding of the serious adverse effects of prolonged paralysis,

together with accepted standards of care for modes of mechanical ventilation in patients with ARDS.

Rapid sequence intubation

Status asthmaticus

Elevated ICP

Elevated intra-abdominal pressure

Targeted temperature management after cardiac arrest

Cisatracurium has been the most-studied NMBA for ARDS since 2000, primarily as short-term

treatment and in severe cases of ARDS. In 2010, a randomized placebo-controlled trial (n=340) found

that short-term fixed-dose cisatracurium (48 hours) significantly improved 90-day survival, increased

ventilator-free days, increased organ dysfunction–free days, and decreased barotrauma in patients with

severe ARDS (Pao2/Fio2 less than 120 mm Hg). The investigators found no difference in neuromuscular

weakness compared with placebo. Other cisatracurium studies have shown improvements in oxygenation

and a reduction in inflammatory mediators.

mechanical ventilation, prolonged ICU length of stay, and increased mortality.

Protective mechanisms of NMBAs in severe ARDS: Researchers have proposed mechanisms by which

an NMBA may protect the lung against further injury in severe ARDS. These mechanisms are not

completely understood, but they may help explain the beneficial effects of NMBAs in early, severe

ARDS:

Provide improved adaptation to the ventilator through increased thoracopulmonary compliance.

Increase functional residual capacity, and decrease intrapulmonary shunt.

Provide uniform distribution of pulmonary perfusion and pressures, favoring the perfusion of

ventilated areas.

Decrease muscular oxygen consumption by decreasing ventilator asynchrony.

Decrease production of proinflammatory cytokines in lungs and blood.

Provide protective role against ventilator-induced trauma, including decreased incidence of

pneumothoraces.

The 2016 SCCM NMBA guidelines suggest that a NMBA be administered by continuous intravenous

infusion early in the course of ARDS for patients with a Pao2/Fio2 of less than 150 mm Hg (weak

recommendation). Use of NMBAs in ARDS remains controversial. Short-term use of cisatracurium (48

hours or less) when used early may be beneficial for severe ARDS (Pao2/Fio2 less than 120 mm Hg). The

Reevaluation of Systemic Early Neuromuscular Blockade (ROSE) PETAL was a randomized, parallel-

design study comparing cisatracurium with placebo for 48 hours on the effects of 90-day mortality. It

was published after the guidelines and did not support using this early in course of ARDS.