The Effects of Neuromuscular-Blocking Agents on Gas Exchange in Patients With Acute Respiratory Distress Syndrome

Abstract

The use of neuromuscular-blocking agents (NMBA) in ventilated patients with acute respiratory distress syndrome (ARDS) is controversial and largely empiric. Few trials looked at their effectiveness on gas exchange or in improving lung mechanics in patients with ARDS. Only one randomized, controlled trial compared the effects of NMBA on gas exchange in patients with ARDS receiving NMBA as compared with patients receiving placebo throughout a period of 48 hours. In this trial, the early use of NMBA in patients with ARDS was associated with a sustained improvement in oxygenation. The muscular paralysis induced by NMBA could reduce the consumption of oxygen linked to the work of breathing. Muscular paralysis could facilitate mechanical ventilation by preventing spontaneous breaths responsible for the dys-synchrony and worsening of gas exchange. Muscular paralysis could increase compliance of the thoracic wall and improve mechanical ventilation during ARDS. However, these hypotheses are controversial. Finally, preliminary data show that the muscular paralysis could provide better adaptation to mechanical ventilation and better satisfaction with the protective criteria for reduction of ventilator-associated lung injuries by homogenizing the distribution of tidal volume and positive end expiratory pressure. The role of new NMBA (benzylisoquinolines) in the occurrence of critical illness neuromyopathy is largely questioned in the recent literature. It is important to design new studies to explain the mechanisms of the improvement in oxygenation associated with NMBA and to evaluate whether the use of NMBA modifies the outcome of patients with ARDS.

Mechanical Ventilation Preserves Diaphragm Mitochondrial Function in a Rat Sepsis Model

“…Atracurium is a skeletal muscle relaxant and has been shown to decrease muscle and serum in ammatory response and to improve diaphragm function in experimental sepsis [26]. We used this medication in our experiment to avoid excessive muscle activity [43]. However, contrary to what was previously reported, we found no signi cant improvement in diaphragm force or diaphragm in ammatory response ( Fig.…”

“…Half of the CLP and control rats were then chemically paralyzed and underwent MV (n = 6 per group). To limit excessive muscle activity causing a drop in lung compliance and increased airway pressure, [43] MV rats were paralyzed using a synthetic non-depolarizing neuromuscular blocking agent (atracurium besilate, 0.3 mg.kg − 1 ) administered every 2 h via a jugular catheter. The trachea was then cannulated, and the rats were intubated and ventilated with a ventilator (7025 Rodent Ventilator; Ugo Basile, Comerio, Italy) equipped with standard sterile tubing and lters.…”

Mechanical ventilation preserves diaphragm mitochondrial function in a rat sepsis model

“…Atracurium is a skeletal muscle relaxant and has been shown to decrease muscle and serum inflammatory response and to improve diaphragm function in experimental sepsis [ 45 ]. We used this medication in our experiment to avoid excessive muscle activity [ 22 ]. However, contrary to what was previously reported, we found no significant improvement in diaphragm force or diaphragm inflammatory response (Figs.…”

“…Half of the CLP and control rats were then chemically paralyzed and underwent MV ( n = 6 per group). To limit excessive muscle activity causing a drop in lung compliance and increased airway pressure [ 22 ], MV rats were paralyzed using a synthetic non-depolarizing neuromuscular blocking agent (atracurium besilate, 0.3 mg.kg −1 ) administered every 2 h via a jugular catheter. The trachea was then cannulated, and the rats were intubated and ventilated with a ventilator (7025 Rodent Ventilator; Ugo Basile, Comerio, Italy) equipped with standard sterile tubing and filters.…”