What is the recommended approach for clinical assessment of neuromuscular monitoring in Intensive Care Unit (ICU)?

From the Guidelines

The recommended approach for clinical assessment of neuromuscular monitoring in the ICU involves using quantitative train-of-four (TOF) monitoring as the primary method, as supported by the most recent and highest quality study 1. This technique uses peripheral nerve stimulators to deliver four electrical impulses to a peripheral nerve (typically the ulnar nerve at the wrist), while measuring the resulting muscle contractions (usually of the adductor pollicis muscle). The ratio of the fourth twitch to the first twitch (TOF ratio) provides objective data about neuromuscular blockade depth. A TOF ratio of 0.9 or greater indicates adequate recovery from neuromuscular blocking agents (NMBAs). Clinical assessment should be performed at baseline before NMBA administration, 30-60 minutes after initiation, and at least every 12 hours during continuous infusion. For patients receiving NMBAs like rocuronium, vecuronium, or cisatracurium, maintaining one or two twitches on TOF monitoring typically provides adequate paralysis while minimizing drug accumulation. Visual or tactile assessment of TOF responses is insufficient and can overestimate recovery. Quantitative monitoring helps prevent complications like prolonged paralysis, ICU-acquired weakness, and ventilator-associated pneumonia by enabling precise NMBA dosing. This approach allows clinicians to balance the benefits of neuromuscular blockade with the risks of oversedation and prolonged paralysis.

Some key points to consider when implementing this approach include:

• The use of quantitative TOF monitoring to assess neuromuscular blockade depth 1
• The importance of clinical assessment at baseline and regularly during NMBA administration 1
• The need to maintain one or two twitches on TOF monitoring to minimize drug accumulation and prevent complications 1
• The limitations of visual or tactile assessment of TOF responses and the potential for overestimation of recovery 1

Overall, the use of quantitative TOF monitoring as the primary method for clinical assessment of neuromuscular monitoring in the ICU is supported by the most recent and highest quality evidence, and is recommended as the best approach for minimizing complications and optimizing patient outcomes 1.

From the FDA Drug Label

IN THE INTENSIVE CARE UNIT, APPROPRIATE MONITORING, WITH THE USE OF A PERIPHERAL NERVE STIMULATOR TO ASSESS THE DEGREE OF NEUROMUSCULAR BLOCKADE IS RECOMMENDED TO HELP PRECLUDE POSSIBLE PROLONGATION OF THE BLOCKADE WHENEVER THE USE OF VECURONIUM OR ANY NEUROMUSCULAR BLOCKING AGENT IS CONTEMPLATED IN THE ICU, IT IS RECOMMENDED THAT NEUROMUSCULAR TRANSMISSION BE MONITORED CONTINUOUSLY DURING ADMINISTRATION AND RECOVERY WITH THE HELP OF A NERVE STIMULATOR ADDITIONAL DOSES OF VECURONIUM BROMIDE OR ANY OTHER NEUROMUSCULAR BLOCKING AGENT SHOULD NOT BE GIVEN BEFORE THERE IS A DEFINITE RESPONSE TO T1 OR TO THE FIRST TWITCH. In patients who are known to have myasthenia gravis or the myasthenic (Eaton-Lambert) syndrome, small doses of vecuronium bromide may have profound effects. In such patients, a peripheral nerve stimulator and use of a small test dose may be of value in monitoring the response to administration of muscle relaxants

The recommended approach for clinical assessment of neuromuscular monitoring in Intensive Care Unit (ICU) is to use a peripheral nerve stimulator to assess the degree of neuromuscular blockade and monitor neuromuscular transmission continuously during administration and recovery.

• Key points:
  • Monitor neuromuscular transmission with a nerve stimulator
  • Do not give additional doses without a definite response to T1 or the first twitch
  • Use a small test dose in patients with myasthenia gravis or the myasthenic syndrome
  • Monitor continuously during administration and recovery 2 2

From the Research

Clinical Assessment of Neuromuscular Monitoring in ICU

The clinical assessment of neuromuscular monitoring in the Intensive Care Unit (ICU) is crucial for patients receiving neuromuscular blocking agents (NMB). The following points highlight the recommended approach for clinical assessment:

• Train-of-Four (TOF) Monitoring: TOF monitoring is often recommended during the continuous use of NMB in the ICU 3, 4, 5. However, studies have shown that careful titration of NMB using clinical bedside markers should remain the standard of care with these drugs 3, 5.
• Clinical Assessment: Clinical assessment is a widely used method for monitoring neuromuscular blockade in ICU patients 3, 4, 5. However, studies have shown that clinical assessment may not always be accurate, and TOF monitoring can provide more objective measurements 4, 6.
• Comparison of TOF Monitoring and Clinical Assessment: Studies have compared TOF monitoring and clinical assessment in ICU patients receiving NMB 3, 4, 5. The results have shown that TOF monitoring does not lead to improved recovery time or lower cisatracurium dosing compared with monitoring by clinical assessment 5.
• Acceleromyography and Tactile Assessment: Acceleromyography is a new method for monitoring neuromuscular block, and it has been compared with tactile assessment by nursing staff 6. The results have shown that nurses tend to overestimate the degree of block using tactile assessment of TOF ratio.
• Monitoring Practices: Variations exist in monitoring practices and in the use of peripheral nerve stimulators, including the frequency of monitoring and use of the baseline milliamperage 7. Appropriate monitoring and titration of NMB by ICU nurses may aid in preventing adverse effects, including the potential for prolonged neuromuscular blockade.

Key Findings

• TOF monitoring is recommended during the continuous use of NMB in the ICU, but careful titration of NMB using clinical bedside markers should remain the standard of care with these drugs 3, 5.
• Clinical assessment may not always be accurate, and TOF monitoring can provide more objective measurements 4, 6.
• Variations exist in monitoring practices and in the use of peripheral nerve stimulators, and appropriate monitoring and titration of NMB by ICU nurses may aid in preventing adverse effects 7.

Recommendations for Clinical Practice

• ICU nurses should be aware of the importance of accurate monitoring and titration of NMB to prevent adverse effects 7.
• TOF monitoring should be used in conjunction with clinical assessment to provide more objective measurements of neuromuscular blockade 4, 6.
• Further studies are needed to determine the best approach for clinical assessment of neuromuscular monitoring in ICU patients receiving NMB 3, 4, 5.