Neuromuscular Junction Antagonists

Indications

Need for Procedural/Operative Paralysis
Need for Sedation to Facilitate Mechanical Ventilation in Acute Respiratory Distress Syndrome (ARDS) (see Acute Respiratory Distress Syndrome)
Rapid Sequence Intubation (RSI) (see Airway Management)

Inspiratory Force (At Least -40 cm H2O): may be difficult to perform without endotracheal intubation, but is a reliable gauge of normal diaphragmatic function
- Approximate Percentage of Receptors Occupied When Response Returns to a Normal Value: 50%
Tidal Volume (At Least 5 mL/kg): insensitive as an indicator of peripheral neuromuscular function
- Approximate Percentage of Receptors Occupied When Response Returns to a Normal Value: 80%
Train-of-Four: standard lay used to monitor depth of paralysis
- Approximate Percentage of Receptors Occupied When Response Returns to a Normal Value: 75%

Study of Pupillary Response in the Setting of Pharmacologic Paralysis with Neuromuscular Junction Antagonists (Arch Neurol, 1997) [MEDLINE]
- Systemically Administered Neuromuscular Blocking Drugs (Vecuronium, Pancuronium) Do Not Acutely Affect the Pupillary Light Reflex in Healthy, Anesthetized Patients
Study of Pupillary Response in Setting of Use of Neuromuscular Junction Antagonists (Ann Emerg Med, 2011) [MEDLINE]
- Pupillary Response is Preserved in 91% of Patients Undergoing Rapid Sequence Intubation (RSI) with Succinylcholine
- Pupillary Response is Preserved in 100% of Patients Undergoing Rapid Sequence Intubation (RSI) with Rocuronium

Increased Risk of Postoperative Pulmonary Complications
- European Multicenter, Prospective Observational Cohort Study of Intraoperative Use of Neuromuscular Junction Antagonists (Lancet Respir Med, 2019) [MEDLINE]: n = 22,803 (from 28 European countries)
  - Intraoperative Use of Neuromuscular Junction Antagonists (in Association with General Anesthesia) was Associated with an Increased Risk of Postoperative Pulmonary Complications (1658 [7.6%] of 21, 694); ORadj 1.86, 95% CI 1.53-2.26; ARRadj -4·4%, 95% CI -5.5 to -3.2)
  - Only 2·3% of high-risk surgical patients and those with adverse respiratory profiles were anaesthetised without neuromuscular blocking agents
  - The use of neuromuscular monitoring (ORadj 1·31, 95% CI 1·15-1·49; ARRadj -2·6%, 95% CI -3·9 to -1·4) and the administration of reversal agents (1·23, 1·07-1·41; -1·9%, -3·2 to -0·7) were not associated with a decreased risk of postoperative pulmonary complications
  - Neither the choice of sugammadex instead of neostigmine for reversal (ORadj 1·03, 95% CI 0·85-1·25; ARRadj -0·3%, 95% CI -2·4 to 1·5) nor extubation at a train-of-four ratio of 0·9 or more (1·03, 0·82-1·31; -0·4%, -3·5 to 2·2) was associated with better pulmonary outcomes

Clinical practice guidelines for sustained neuromuscular blockade in the adult critically ill patient. Crit Care Med. 2002;30:142-158
Elimination of atracurium in humans: contribution of Hofmann elimination and ester hydrolysis versus organ-based elimination. Anesthesiology. 1986;65:6-12

Neuromuscular blocking drugs do not alter the pupillary light reflex of anesthetized humans. Arch Neurol. 1997 May;54(5):579-84. doi: 10.1001/archneur.1997.00550170055014 [MEDLINE]
Pupillary response to light is preserved in the majority of patients undergoing rapid sequence intubation. Ann Emerg Med 2011; 57:234-237 [MEDLINE]
Post-anaesthesia pulmonary complications after use of muscle relaxants (POPULAR): a multicentre, prospective observational study. Lancet Respir Med. 2019 Feb;7(2):129-140. doi: 10.1016/S2213-2600(18)30294-7 [MEDLINE]