This is a review of the Society of Critical Care Medicine’s updated (2016) clinical practice guidelines for sustained neuromuscular blockade in the adult critically ill patient. These updated guidelines replace the 2002 version and include new data on the clinical use of neuromuscular blockers in the ICU. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology has been used to assess the quality of evidence and strength of recommendation.
What happens at the neuromuscular junction?
Neuromuscular blocking agents (NMBAs) are structurally related to acetylcholine (ACh). NMBAs interfere with the binding of Ach to the motor end plate of the neuromuscular junction.
The neuromuscular junction consists of the nerve terminal, synaptic cleft, and motor end plate.
There are 2 types of NMBAs that differ based on their mechanism of action:
Depolarizing NMBAs: Bind directly to cholinergic receptors on the motor endplate
Non-depolarizing NMBAs: Competitively inhibit ACh receptor on the motor endplate
Guideline Recommendations (2016)
1. Acute respiratory distress syndrome (ARDS): Suggest continuous IV infusion early in course of ARDS for patients with Pao2/Fio2 less than 150 (weak recommendation, moderate-quality evidence)
2. Status asthmaticus: Suggest against routine administration of NMBAs in mechanically ventilated patients with status asthmaticus (weak recommendation, very low quality of evidence)
3. Elevated intracranial pressure (ICP): No recommendation as to whether neuromuscular blockade is beneficial or harmful in patients with acute brain injury and elevated ICP (insufficient evidence)
4. Therapeutic hypothermia: Suggest that NMBAs can be used to manage overt shivering in therapeutic hypothermia (weak recommendation, very low quality of evidence)
5. Peripheral nerve stimulator (PNS) use in therapeutic hypothermia: No recommendation on use of PNS to monitor degree of block in patients undergoing therapeutic hypothermia (insufficient evidence)
6. Protocol guidance of NMBA administration in therapeutic hypothermia: Recommend using a protocol to guide NMBA administration in patients undergoing therapeutic hypothermia
7. Hemodynamic indications: No recommendation on the use of NMBAs to improve accuracy of intravascular-volume assessment in mechanically ventilated patients (insufficient evidence)
8. Sedation and analgesia: Recommend patients receiving NMBAs receive optimal analgesic and sedative drugs to achieve deep sedation (good practice statement)
9. Electroencephalogram-derived parameters: No recommendation on use of electroencephalogram-derived parameters as measure of sedation during continuous infusion of NMBAs (insufficient evidence)