Book
Monitoring and Antagonism of Neuromuscular Blockade
- Annexes
Annex 1:
Evidence-to-Decision Tables
1. Monitoring Neuromuscular Blockade
|
Domain |
Evidence Summary |
|
Problem |
Residual neuromuscular blockade increases the risk of hypoxemia, airway obstruction, aspiration, and postoperative complications. |
|
Benefit |
Objective monitoring (quantitative train-of-four [TOF]) reduces the incidence of residual paralysis and improves patient safety. |
|
Benefit Direction |
Strongly positive – consistent reduction in adverse outcomes. |
|
Risk/Harm |
Minimal; requires equipment and training. False reassurance is possible if only qualitative monitoring is used. |
|
Certainty of Evidence |
Moderate to high – multiple RCTs and meta-analyses support quantitative monitoring. |
|
Values and Preferences |
Patients & clinicians value safety, avoidance of reintubation & smooth recovery. |
|
Resource Use |
Requires investment in quantitative monitors; costs vary but are generally modest compared to the potential complications. |
|
Equity |
Access may be limited in resource-constrained settings; high-income centers are more likely to adopt. |
|
Acceptability |
High among anesthesiologists; increasingly considered standard of care. |
|
Feasibility |
Feasible with training and institutional support; barriers include equipment availability. |
|
Recommendation |
Strong recommendation: Use quantitative neuromuscular monitoring whenever neuromuscular blocking agents are administered. |
2. Choice of Reversal Agent (Neostigmine vs. Sugammadex)
|
Domain |
Neostigmine |
Sugammadex |
|
Problem Addressed |
Routine reversal of shallow/moderate blockade |
Rapid reversal of aminosteroid blockade, even deep |
|
Benefit |
Effective, inexpensive |
Highly effective, rapid, predictable |
|
Benefit Direction |
Positive but limited |
Strongly positive |
|
Risk/Harm |
Bradycardia, incomplete reversal |
Rare hypersensitivity, high cost |
|
Certainty of Evidence |
High |
High |
|
Values & Preferences |
Acceptable, widely used |
Preferred when speed/safety critical |
|
Resource Use |
Low cost |
High cost |
|
Equity |
Widely available |
Limited in resource‑constrained settings |
|
Acceptability |
High |
High, but a cost barrier |
|
Feasibility |
Easy, requires an anticholinergic |
Easy, no adjunct needed |
|
Recommendation |
Use for routine cases |
Use when rapid, reliable reversal needed |
3. Antagonism of Neuromuscular Blockade
|
Domain |
Evidence Summary |
|
Problem |
Residual blockade persists if antagonism is not performed or is inadequate, leading to respiratory complications. |
|
Benefit |
Antagonists (neostigmine, sugammadex) reliably reverse blockade, reducing postoperative complications. |
|
Benefit Direction |
Strongly positive – reversal agents improve safety and recovery. |
|
Risk/Harm |
Neostigmine: risk of bradycardia, incomplete reversal if given too early. Sugammadex: rare hypersensitivity, higher cost. |
|
Certainty of Evidence |
High – robust evidence supports the efficacy of both agents. |
|
Values and Preferences |
Patients value rapid, safe recovery; clinicians prefer predictable reversal. Sugammadex often preferred for aminosteroid agents due to speed and reliability. |
|
Resource Use |
Neostigmine is inexpensive; sugammadex is costly but may reduce ICU admissions and complications. |
|
Equity |
Sugammadex availability is limited in low-resource settings; neostigmine is widely accessible. |
|
Acceptability |
High; sugammadex is increasingly accepted despite cost. |
|
Feasibility |
Both agents are feasible; the choice depends on institutional resources and drug availability. |
|
Recommendation |
Strong recommendation: Always antagonize neuromuscular blockade unless full recovery is objectively confirmed. Prefer sugammadex for aminosteroid agents when available; otherwise, use neostigmine with appropriate monitoring. |
4. Perioperative Safety & Systems
|
Domain |
Evidence Summary |
|
Problem |
Residual blockade contributes to morbidity, ICU admissions, and prolonged recovery. |
|
Benefit |
Standardized monitoring and reversal protocols reduce complications. |
|
Benefit Direction |
Strongly positive. |
|
Risk/Harm |
Minimal; requires institutional buy‑in. |
|
Certainty of Evidence |
Moderate–high. |
|
Values & Preferences |
Strong preference for patient safety. |
|
Resource Use |
Institutional investment in monitors and drug supply. |
|
Equity |
Disparities in access to sugammadex and monitors. |
|
Acceptability |
High among clinicians and patients. |
|
Feasibility |
Feasible with training, guidelines, and policy support. |
|
Recommendation |
Strong recommendation: Implement institutional protocols for monitoring and reversal to ensure patient safety. |
Annex 2:
Key Stimulation Modalities
· Train-of-Four (TOF): The gold-standard test delivering 4 rapid impulses at 2 Hz. It tracks "fade," measuring the ratio of the 4th twitch amplitude to the 1st (T4:T1).
· Post-Tetanic Count (PTC): Used for intense blocks when TOF shows 0 twitches. A 50 Hz stimulus is given followed by single twitches to gauge how close the patient is to returning to a measurable TOF.
· Double Burst Stimulation (DBS): Two short bursts of tetanic stimuli used to make visual/tactile fade easier to spot when electronic tools are limited.
Depth Classifications
The depth of paralysis is clinically staged by muscle responses:
· Deep Block: PTC ≥ 1, but TOF count is 0.
· Moderate Block: TOF count reads 1 to 3 twitches.
· Shallow Block: TOF count is 4, but the TOF ratio is < 0.4.
· Minimal Block: TOF ratio is between 0.4 and < 0.9.
· Acceptable Recovery: TOF ratio is ≥ 0.9.
Annex 3:
Monitoring Sites [1]
While different eye muscles have different characteristics, distinguishing the evoked responses from orbicularis oculi and corrugator supercilii muscles is often difficult [14]. We therefore make the same recommendations for all eye muscles. The adductor pollicis muscle recovers more slowly than the corrugator supercilii or orbicularis oculi muscle. There are higher simultaneous train-of-four ratios at the corrugator supercilii, and orbicularis oculi muscles compared with the adductor pollicis. Residual neuromuscular blockade is defined as a train-of-four ratio less than 0.9 at the adductor pollicis muscle, and it is therefore optimal to confirm adequate recovery by obtaining a valid measurement at this site. A valid measurement of the depth of the neuromuscular blockade is also essential to guide selection of the pharmacological antagonist drug and dosage. Therefore, if intraoperative neuromuscular monitoring has been performed at the eye muscles because no other site was easily accessible intraoperatively, then we recommend changing the site to the adductor pollicis muscle before antagonism. Dosage recommendations for pharmacological antagonist drugs are based on the adductor pollicis muscle responses. When monitoring at the corrugator supercilii muscle, dosage recommendations approved by the FDA for sugammadex are not applicable [15]. For these reasons, the adductor pollicis muscle is a safer option than the orbicularis oculi or corrugator supercilii. The time to recovery is similar between the adductor pollicis and masseter muscles, although the data are very limited.
In the hand, there are three muscles most commonly monitored using electromyography. These muscles are the adductor pollicis (palmar portion of the thumb), the first dorsal interosseous (posterior aspect of hand between the thumb and index finger), and the abductor digiti minimi (medial aspect of palm proximal to the pinky finger). The reference site of measurement is the adductor pollicis muscle. Train-of-four ratios at the adductor pollicis and first dorsal interosseous muscles are similar when measured simultaneously, and therefore, it appears reasonable to use data interchangeably between these sites, especially if the adductor pollicis muscle is not available or signal quality is poor. Train-of-four ratios at the adductor pollicis muscle are lower than the abductor digiti minimi when measured simultaneously, indicating a relative resistance to neuromuscular blockade at the abductor digiti minimi. Therefore, data from the abductor digiti minimi muscle should be used with caution to guide neuromuscular blockade management (understanding the patient is more deeply paralyzed than the monitor indicates). Direct comparisons of the two alternate muscles, the first dorsal interosseous and the abductor digiti minimi, reveal the same pattern of relative resistance at the abductor digiti minimi muscle, reinforcing that measurements at the adductor pollicis and the first dorsal interosseous offer a higher margin of patient safety.
The time to recovery is similar between the adductor pollicis and masseter muscles, although the data are very limited. The data on the flexor hallucis muscle are inconsistent; however, the time to recovery is more similar between the adductor pollicis and flexor hallucis than between adductor pollicis and the eye muscles.
Annex 4:
|
Strategies for Implementation and Acceptance of Routine Quantitative Monitoring [1] |
|
- Educate clinicians on the prevalence and consequences of residual neuromuscular blockade in routine care; provide key references. - Provide in-service training on quantitative monitoring technology, emphasizing the increasing ease of use and interpretation. - Work with the operating room value-based-purchasing committee (or local equivalent) to define appropriate indications and contraindications for quantitative monitoring. Include all patients receiving neuromuscular blocking drugs, with particular focus on patients receiving nondepolarizing neuromuscular blocking drug. - Ensure that monitors are readily available. - Seek opportunities to document and promote results within your group and institution to enable: - A decrease in incidence of postoperative respiratory complications. - A decrease in ICU and hospital length of stay. - An increase in patient satisfaction. - Changes in the use of antagonist drugs. - Provide team and individual feedback on appropriate use of quantitative monitoring. |
