[Use of neuromuscular blocking agents and reversal of blockade: guidelines from Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor]

Quantitative Neuromuscular Monitoring and Postoperative Outcomes: A Narrative Review

Over the past five decades, quantitative neuromuscular monitoring devices have been used to examine the incidence of postoperative residual neuromuscular block in international clinical practices, and to determine their role in reducing the risk of residual neuromuscular block and associated adverse clinical outcomes. Several clinical trials and a recent meta-analysis have documented that the intraoperative application of quantitative monitoring significantly reduces the risk of residual neuromuscular blockade in the operating room and postanesthesia care unit. In addition, emerging data show that quantitative monitoring minimizes the risk of adverse clinical events, such as unplanned postoperative reintubations, hypoxemia, and postoperative episodes of airway obstruction associated with incomplete neuromuscular recovery, and may improve postoperative respiratory outcomes. Several international anesthesia societies have recommended that quantitative monitoring be performed whenever a neuromuscular blocking agent is administered. Therefore, a comprehensive review of the literature was performed to determine the potential benefits of quantitative monitoring in the perioperative setting.

Monitoring intraoperative neuromuscular blockade and blood pressure with one device (TOF-Cuff): A comparative study with mechanomyography and invasive blood pressure

OBJECTIVE

The overall objective of the study is to determine the ability of TOF-Cuff device (blood-pressure modified cuff, including stimulation electrodes) to monitor with the same device the non-invasive blood pressure (NIBP) and the depth of a neuromuscular blockade (NMB) induced pharmacologically, by stimulation of the brachial plexus at the humeral level and recording evoked changes in arterial pressure.

MATERIAL AND METHOD

Clinical, single-centre, open-controlled study with 32 adult patients ASA I-III for scheduled elective surgery under general anaesthesia in supine position, for the validation of neuromuscular monitoring, comparing the values obtained from neuromuscular relaxation TOF-Cuff with those obtained by mechanomyography (MMG) (control method) during the recovery phase of NMB, when a TOF ratio>0.7 and>0.9 (primary endpoint) were reached respectively. And an additional consecutive study of 17 patients for validation of NIBP monitoring with TOF-Cuff device vs invasive blood pressure measured by an intra-arterial catheter. All data were analyzed using the Bland-Altman method.

RESULTS

Recovery from NMB measured with the TOF-Cuff was earlier compared to MMG. Comparing TOF-ratio>0.9 measured with TOF-Cuff vs TOF-ratio>0.7 with MMG, a specificity of 91% and a positive predictive value of 84% were obtained. In NIBP measurement, the mean error and standard deviation of both systolic blood pressure (1.6±7mmHg) and diastolic blood pressure (-3.4±6.3) were within the European accuracy requirements for medical devices.

CONCLUSIONS

The TOF-Cuff device has been shown to be valid and safe in the monitoring of NMB and in the measurement of NIBP, with no patient presenting any adverse events, skin-level lesions or residual pain. It is not interchangeable with MMG, having a TOF-ratio>0.9 quantified by the TOF-Cuff device, a good correlation with a TOF-ratio>0.7 on MMG.

Recommendations on the use of deep neuromuscular blockade by anaesthesiologists and surgeons. AQUILES (Anestesia QUIrúrgica para Lograr Eficiencia y Seguridad) Consensus

INTRODUCTION

Neuromuscular blockade enables airway management, ventilation and surgical procedures. However there is no national consensus on its routine clinical use. The objective was to establish the degree of agreement among anaesthesiologists and general surgeons on the clinical use of neuromuscular blockade in order to make recommendations to improve its use during surgical procedures.

METHODS

Multidisciplinary consensus study in Spain. Anaesthesiologists experts in neuromuscular blockade management (n=65) and general surgeons (n=36) were included. Delphi methodology was selected. A survey with 17 final questions developed by a dedicated scientific committee was designed. The experts answered the successive questions in two waves. The survey included questions on: type of surgery, type of patient, benefits/harm during and after surgery, impact of objective neuromuscular monitoring and use of reversal drugs, viability of a multidisciplinary and efficient approach to the whole surgical procedure, focussing on the level of neuromuscular blockade.

RESULTS

Five recommendations were agreed: 1) deep neuromuscular blockade is very appropriate for abdominal surgery (degree of agreement 94.1%), 2) and in obese patients (76.2%); 3) deep neuromuscular blockade maintenance until end of surgery might be beneficial in terms of clinical aspects, such as as immobility or better surgical access (86.1 to 72.3%); 4) quantitative monitoring and reversal drugs availability is recommended (89.1%); finally 5) anaesthesiologists/surgeons joint protocols are recommended.

CONCLUSIONS

Collaboration among anaesthesiologists and surgeons has enabled some general recommendations to be established on deep neuromuscular blockade use during abdominal surgery.

[Monitoring of recurrent laryngeal nerve injury using an electromyographic endotracheal tube in thyroid and parathyroid surgery. Anesthetic aspects]

Recurrent laryngeal nerve injury remains one of the main complications in thyroid and parathyroid surgery. When this injury is bilateral, an acute upper airway obstruction may occur, leading to a potentially life-threatening situation for the patient. The visual identification of the nerve during surgery is the best way to preserve its integrity. However identification of the nerves by means of electromyographic stimuli through electrodes attached to endotracheal tubes could help in decreasing nerve injury. In these cases the experience and role of the anesthetist is essential to correctly place the electromyographic endotracheal tube and ensure that the electrodes are in touch with the vocal cords during the surgery. Moreover, the results of the electromyography can be affected by the neuromuscular blocking agents. Therefore, the choice and dose must be adapted, in order to ensure a suitable anesthetic depth, and adequate response.

[Neostigmine-induced neuromuscular blockade in the corrugator supercilii muscle]

OBJECTIVE

To investigate whether a single dose of neostigmine, administered when the adductor pollicis muscle presents 2 twitches in train-of-four (TOF) stimulation, can reduce the TOF ratio in the corrugator supercilii muscle.

PATIENTS AND METHODS

We designed a case-control study of patients between 18 and 65 years of age classified ASA 1-2. We used 2 accelerometers--1 for the cubital nerve/thumb adductor muscle and 1 for the facial nerve/corrugator supercilii muscle. Neuromuscular blockade was induced with 0.6 mg x kg(-1) of rocuronium, and 40 microg x kg(-1) of neostigmine was administered at the third twitch in the TOF in the thumb adductor. If the TOF ratio in the corrugator supercilii fell by 10% or more at that time, the patient was classified as a case. We recorded the age, sex, weight, height, body mass index, duration of the procedure, and TOF ratio in the corrugator supercilii muscle when the neostigmine was administered.

RESULTS

Ten cases and 10 controls were enrolled. No significant differences between cases and controls were found in any variables except the mean (SD) TOF ratio in the corrugator supercilii muscle: 70.9% (17.8%) in cases and 35.3% (7.8%) in controls (P < .001).

CONCLUSIONS

In our patients, administration of neostigmine after the appearance of the third twitch in TOF stimulation of the thumb adductor was associated with a reduction in the TOF ratio in the corrugator supercilii. The similarity between blockades of the corrugator muscle, the diaphragm, and the larynx is of clinical interest.