Comparison of Train-of-Four and Best Clinical Assessment during Continuous Paralysis

Abstract

Train-of-four (TOF) monitoring is recommended in published guidelines during use of continuous-infusion neuromuscular blocking agents (NMB) in the intensive care unit (ICU). To test that recommendation, dual protocols were established in a medical ICU after intensive nursing education. Paralyzed patients received either TOF monitoring with a goal of three twitches or best clinical assessment while receiving atracurium by continuous infusion. Demographics and mean duration of paralysis of 20 patients in the TOF group were no different than that of the 16 patients in the best clinical assessment group. Although most patients demonstrated atracurium tolerance over time, there was no difference between groups in total mg (+/- SEM) infused (10,460 +/- 2,409 versus 9,201 +/- 3,237) or mean microgram/kg/min (15.2 +/- 1.5 versus 12.0 +/- 1.1). The time to clinical recovery was no different between groups (50 +/- 10 versus 45 +/- 12 min). Two complications occurred in the TOF group, with pulmonary emboli despite prophylaxis and an unrecognized cerebrovascular accident in one patient each. We conclude that careful titration of NMB using clinical bedside markers should remain the standard of care with these drugs.

Surviving Sepsis Campaign: International guidelines for management of severe sepsis and septic shock: 2008

“…The peripheral nerve stimulation group received less drug and recovered neuromuscular function and spontaneous ventilation faster than the control group. Nonrandomized observational studies have suggested that peripheral nerve monitoring reduces or has no effect on clinical recovery from NMBAs in the ICU (203,204).…”

Intensive Care Nurses' Knowledge About Use of Neuromuscular Blocking Agents in Patients With Respiratory Failure

“…Studies that have compared TOF-guided NMBA titration to titration based on subjective clinical assessments in patients with mixed indications for paralysis have yielded disparate results. Rudis et al 26 reported that lower doses of NMBAs were used and recovery from paralytic agents was faster in patients randomized to TOF-guided therapy, whereas 2 other studies 27,28 showed no difference between groups in total paralysis time, recovery time, and amount of drug used. In a randomized controlled trial 29 of 102 patients with ARDS who were given cisatracurium, Figure 4 Degree to which baseline factors or concurrent therapies are perceived to alter the risk profile of neuromuscular blocking agents.…”

Effect of neuromuscular blocking agents on gas exchange in patients presenting with acute respiratory distress syndrome*

“…The mechanisms by which muscle paralysis improves oxygenation remain unclear. Indeed, muscle paralysis may reduce oxygen consumption (15,28), facilitate mechanical ventilation by preventing respiratory movements (29), and increase chest wall compliance (3). However, Conti et al (30) showed that there was no effect of NMBA on chest wall, lung, and respiratory system mechanics in 13 patients presenting with acute respiratory failure (four ARDS patients).…”