Barriers and aids to routine neuromuscular monitoring and consistent reversal practice—A qualitative study

Background Neuromuscular monitoring is recommended whenever a neuromuscular blocking agent is administered, but surveys have demonstrated inconsistent monitoring practices. Using qualitative methods, we aimed to explore barriers and aids to routine neuromuscular monitoring and consistent reversal practice. Methods Focus group interviews were conducted to obtain insights into the thoughts and attitudes of individual anaesthetists, as well as the influence of colleagues and department culture. Interviews were conducted at five Danish and one US hospital. Data were analysed using template analysis. Results Danish anaesthetists used objective neuromuscular monitoring when administering a non‐depolarizing relaxant, but had challenges with calibrating the monitor and sometimes interpreting measurements. Residents from the US institution used subjective neuromuscular monitoring, objective neuromuscular monitoring was generally not available and most had not used it. Danish anaesthetists used neuromuscular monitoring to assess readiness for extubation, whereas US residents used subjective neuromuscular monitoring, clinical tests like 5‐second head lift and ventilatory parameters. The residents described a lack of consensus between senior anaesthesiologists in reversal practice and monitoring use. Barriers to consistent and correct neuromuscular monitoring identified included unreliable equipment, time pressure, need for training, misconceptions about pharmacokinetics of neuromuscular blocking agents and residual block, lack of standards and guidelines and departmental culture. Conclusion Using qualitative methods, we found that though Danish anaesthetists generally apply objective neuromuscular monitoring routinely and residents at the US institution often apply subjective neuromuscular monitoring, barriers to consistent and correct use still exist.

The importance of also monitoring the depolarizing block after succinylcholine was demonstrated in a study of awareness at emergence in patients with butyrylcholinesterase (BChE) deficiency. 3 However, surveys and observational studies show that often, objective neuromuscular monitoring equipment is either not available or used inconsistently. [4][5][6][7][8][9] Naguib and colleagues found that most anaesthesiologists in the United States (US) have access to subjective neuromuscular monitoring, but few had access to objective neuromuscular monitoring compared to their European colleagues. 10 The survey also showed that even when both objective and subjective monitoring were available, US respondents were more likely to use the subjective method, though it did not address why. Furthermore, routine reversal of the neuromuscular block was less common among European respondents. 10 Already in 2005, most clinicians in Denmark had access to objective neuromuscular monitoring. 11 However, a more recent survey found that 75% of Danish anaesthetists had technical difficulties with the objective monitors at least 25% of the time. 12 While the surveys have demonstrated a large variability in availability and use of neuromuscular monitoring equipment, little is known about potential barriers to anaesthetists' routine use of neuromuscular monitoring.
Using qualitative methods, we aimed to explore barriers and aids to routine neuromuscular monitoring and consistent reversal practice.

| MATERIAL S AND ME THODS
We conducted a qualitative study based on focus group interviews and surveys of anaesthesiologists' and nurse anaesthetists' clinical practice and used systematic text condensation to extract themes as described by Malterud. 13

| Participants
Focus group interviews were conducted in Denmark between August 2014 and January 2015. When author JLDT was a visiting scholar at the Department of Anaesthesiology at Stanford Medical Center in the Spring of 2017, interviews were conducted with anaesthesia residents to explore differences and similarities between an institution that had not yet implemented objective neuromuscular monitoring and the previously obtained findings from Danish hospitals. In Denmark, we recruited both smaller and larger departments.
For the focus group interviews, we included certified and in-training anaesthesiologists and nurse anaesthetists (collectively referred to as 'anaesthetists').Participants were incentivized to stay after normal work hours with a gift certificate (approximate value of €30), resulting in a convenience-based sample. In the US, we included anaesthesia residents from the Department of Anaesthesiology at Stanford Medical Center. Three specific lectures were allotted as time slots for interviews with first, second-and third-year residents, respectively, resulting in a convenience-based sample. Secondly, we sent a survey to the attendings at the department and other anaesthesia residency programmes in California, US.

| Focus group interviews
We chose focus group interviews as the primary approach because group interaction would encourage respondents to explore and clarify individual and shared perspectives. 14 An interview guide (Appendix 1) was developed based on literature review and the authors' expertise in the subject. Participants were informed that the purpose of the study was to get their view on neuromuscular monitoring and describe the challenges they experience with the subject. They were informed about potential conflicts of interest. The author, JLDT, who had experience from a previous interview study, 3 conducted the interviews as a research fellow in Denmark, and as a visiting scholar at the US institution. In Denmark, additional interviews were conducted until data saturation was achieved as judged by author JLDT, whereas in the US, the interviews were limited to residents at a single programme. The interviews were recorded on a voice recorder and transcribed in their entirety by a research assistant or author JLDT.

| Survey of attendings
We designed an online survey to get the views of attending anaesthesiologists in the US institution on the subjects discussed by residents. The survey contained a total of 14 multiple-choice and open-ended questions. The survey was sent to attendings at the local institution and to two attendings at each of the ten other anaesthesia residency programmes in California.

| Ethics committee approval
According to Danish regulations, approval from the local ethical committee is not required for this type of studies. The Danish part of the study was registered at clinicaltrials.gov (NCT02239965). The Institutional Review Board at Stanford University approved the study protocol for the US part of the study (Protocol # 42091). Verbal consent was obtained from all participants.

Editorial Comment
Inadequate monitoring of neuromuscular blockade and reversal of neuromuscular blocker drug effects can contribute to preventable perioperative patient complications. This qualitative assessment of specialty physician approaches to these issues in two high-income countries and practices show that these issues remain an area where more education and better implementation of the best practice standards can be needed.

| Analysis
Initially, the author JLDT read the transcripts freely, without coding or analysing. The transcript of one focus group interview was then coded, using a priori codes based on the interview guide and own expertise in the subject. Further codes were derived directly from the text as a part of the analysis. Initial coding of the Danish interviews was discussed and revised by the authors JLDT and DØ. The resulting codebook was used as a starting point for the coding of the remaining interviews. Finally, the survey responses were coded. All codes from both Danish and US data were plotted in concept maps to group related codes into themes and subthemes and demonstrate relations. 15 Quotes reported in the results were cleaned for slang phrases and condensed. Danish quotes were translated by author JLDT.
Findings are reported according to the Consolidated Criteria for Reporting Qualitative Research (COREQ) where appropriate. 14 Coding was performed in nVivo 11 for Mac (QSR international).

| RE SULTS
We conducted 6 focus group interviews in 5 Danish teaching hospitals, with five to seven participants in each interview, totalling 40 interviewees. In the US, we conducted three interviews with a total of 21 anaesthesia residents. Surveys were completed by 22 local attendings and by 13 attendings from other programmes in California.
The duration of the focus group interviews was 37-65 minutes.
Analysis of the interviews resulted in three major themes: Use of neuromuscular monitoring and reversal and Barriers and aids to routine neuromuscular monitoring, and Neuromuscular monitoring after succinylcholine. Table 1 and Appendix 2 show the themes with subthemes, codes and illustrative quotes.

| Theme 1: use of neuromuscular monitoring and reversal after non-depolarizing NMBA
The Danish and US anaesthetists generally had access to different types of neuromuscular monitoring. Neuromuscular block was managed differently, depending on the equipment available, as shown in Figure 1. Danish anaesthetists stated that they always apply acceleromyography before administering the non-depolarizing NMBA to check the control response, calibrate the monitor and guide timing of intubation. They would use the monitor to guide maintenance dosing of NMBA, timing and dosing of reversal, and readiness for extubation. The residents at the US institution had access to primarily subjective neuromuscular monitoring and would rarely apply it before administering the first dose of NMBA, but consistently apply it to guide maintenance dosing of NMBA and timing of reversal. They did not check a baseline response before administering NMBA, which sometimes led to confusion about whether the monitor was malfunctioning or the patient was still paralysed when no responses were observed. Residents often used a timer to assess readiness for tracheal intubation, stating 2 minutes as the usual time from administration of NMBA to intubation.
When reversing the neuromuscular blockade, Danish anaesthetists would give a standardized non-weight-based dose of one vial (neostigmine 2.5 mg and glycopyrronium 0.5 mg) and then assess the effect with acceleromyography. They would then rely on the monitor for assessing readiness for extubation, often combined with clinical tests. The residents at the US institution and the attendings based their decision to administer reversal on a range of parameters: duration of the case, time since last administration of NMBA (from 2 to 6 hours) and subjective neuromuscular monitoring. Reversal dosing was either based on subjective monitoring or the same standard weight-based dose was given to all patients. Some residents would always administer at least a small dose of neostigmine, referred to as a 'legal reversal'. Some residents used train-of-four (TOF) and other stimulation patterns to assess readiness for extubation, whereas others would use ventilatory parameters or other clinical tests instead.

| Theme 2: barriers and aids to routine neuromuscular monitoring
Based on the interview data, we identified barriers and aids to routine neuromuscular monitoring. As shown in Figure 2, we further found that attitudes and departmental factors could influence monitoring practice both negatively and positively, that is act both as barriers and aids.

| Barriers
Though monitoring was readily available, even just storing the cable of the monitor in a drawer could pose a barrier to use of the equipment.
Residents from the US institution mentioned faulty twitch monitors and flat batteries, and anaesthetists from both countries reported unreliable equipment leading to not trusting its measurements. Time pressure was also given as an explanation for not monitoring and the patients having arms tucked under surgical drapes and not easily accessible was another cause for frustration. There was a need for training in the setup and interpretation of objective neuromuscular monitoring, the purpose of calibration and risk stratification of residual block vs side effects from neostigmine reversal, knowing the limitations of subjective monitoring, and, in Denmark, managing acceleromyography showing TOF ratios greater than 100%. Several local attendings also requested training in objective neuromuscular monitoring.

| Attitude
The attitude of both the anaesthetist and the attending in charge of patient care was found to influence whether monitoring was applied.
While both Danish and US anaesthetists considered residual neuromuscular block a serious complication and stated that minor degrees Reliability DK-3 I always use neuromuscular monitoring when using non-depolarizing blockers, but I do not trust it completely because it always calibrates to more than 100% Reliability DK-2 That is probably also why many anaesthesiologists, myself included, get tired of the equipment when it does not work: the patient is awake and breathing fine, and the TOF monitor says '0'. You get furious and tear it off. Then the problem arises when it says '0' and the patient is actually paralysed, but you still tear it off and throw it away and awaken them. That would be a mistake, of course, but that is because we do not have equipment that is 100% reliable and you become insecure about its performance, and was it calibrated or not? and can you count on it?
Reliability US-2 A lot of time you can't get a good signal and you cannot get [the quantitative monitor] to go correctly and then you just ignore it.
Time pressure US-2 …if it wasn't like 11 pm at night and there wasn't like this production pressure to get it done, we should have stayed in the OR for fifteen minutes, while it was like 'oh it's okay, it'll be fine' and then we had to re-intubate in the PACU and wait for forty minutes.
Time pressure US-3 I still probably wouldn't use it because you have to do it before you give paralysis, but we usually are in such a rush, once you start sedating you're going to give the paralysis. I don't have time to put on another monitor, give sedation, check, calibrate the accelerometer and then give paralysis and intubate. It's too much of a hassle for too little gain.

Arms tucked DK-2
There is often the challenge with one arm being tucked down the sides, and you have to put two venous catheters, an arterial canula, a TOF monitor, and a pulse oximeter, and it all goes into that one arm.

NM after succinylcholine
No pain DK-3 Let us say, then, that you had an awareness experience, and you were lying there after a short procedure-you are not having surgery at that time, so there is no pain. There is the feeling of suffocation, that is certainly not comfortable, either, but it is not major heart surgery or emergency caesarean section.
BChE rare DK-1 There are many things we see once, or has happened in the last 10 years at this hospital, but that does not necessarily lead to a bigger change, because then you would have to change things all the time, which perhaps induces uncertainty because people are not confident in what they are doing. Overcomplicating DK-1 It is also a question of not making a relatively simple procedure into a big thing. As soon as you start putting more wires on the patient and doing stuff, then maybe they need a central venous catheter, too, and then they all get an arterial canula. How intensely should a perfectly healthy patient having a 15-minute gastroscopy be monitored?
Overcomplicating DK-3 I also think that sometimes with the short procedures, we spent some time [applying monitoring] and resources that could have been spent differently, because you know what the half-life is. And if there is a problem, you put the monitor on.
Time pressure DK-4 You should not underestimate the effect of this being a production, and it has to run smoothly, and we should not prolong patient turnover times Experience changing behaviour US-3 And then I usually always check at least once after I've given it to put in document, but that's because I've had a case where I gave it and then four hours later didn't check it prior to wean somebody of the ventilator and then they were still paralysed and I realized that they had pseudocholinesterase deficiency. So now I check everybody Experience not changing behaviour DK-1 Well, we do have a colleague who was anaesthetized and she had [BChE deficiency]. And she did not think it was particularly funny to wake up, and get succinylcholine, and not being able to breathe, so… Maybe we should consider it, but we have given it so many times without.

US-3
It was during my PACU rotation, patient just didn't move after surgery, so we brought her out on the ventilator and they had to extubate her like a couple of hours later. And we thought that it was most likely pseudocholinesterase deficiency and she hadn't mentioned anything but she had had surgery years before and was like 'oh, yeah it took me a while to wake up'.
Routine DK-5 I never used the monitor for rapid sequence induction, did you? If only using succinylcholine? I never did that. I used to do it in the old days, but now, I mostly do not Before non-dep. DK-3 But it does not have to be on for intubation with succinylcholine, but it is applied and turned on before administering rocuronium.
Before non-dep. US-1 And I try to remember to always check it if I gave succinylcholine before I give rocuronium to make sure that the twitches came back.

| Aids
Danish anaesthetists described it as helpful to have the TOF measurements shown directly on the monitoring screen. Both Danish and US anaesthetists discussed the importance of having reliable equipment, and most Danish anaesthetists were of the opinion that the current integrated equipment was better than the standalone monitoring devices that had been available before. Some residents from the US institution described how they applied monitoring solely so they could document it in case a claim was filed.

| Theme 3: neuromuscular monitoring after succinylcholine
While some barriers, like time-pressure and 'keeping it simple', also affected application of neuromuscular monitoring after succinylcholine, some arguments against routine monitoring were unique.
Opinions expressed included that BChE deficiency is so rare, that if paralysed at the end of anaesthesia the patient would not feel pain, that patients with BChE deficiency will often know beforehand and warn the anaesthetist, or that the deficiency will be discovered eventually, anyway, by the patient not breathing. In some instances, a single experience with severe residual block after succinylcholine was enough to make the anaesthetist apply monitoring routinely, whereas at one Danish hospital, most anaesthetists did not apply routine monitoring despite having a colleague who had severe BChE deficiency and had shared her story of being awake while paralysed.

| Use of neuromuscular monitoring and reversal
The US residents mostly used a timer to assess readiness for intubation, whereas the Danish anaesthetist relied on objective neuromuscular monitoring, some stating TOF count 1 or 2 as appropriate for intubation. Arguments could be made for and against both approaches: Some variability in the onset of neuromuscular blockers must be expected in all patients, especially those with organ disease and with varying doses. 16,17 On the other hand, the appropriateness of relying on neuromuscular monitoring would also depend on at what TOF value one chooses to perform intubation, as peak relaxation at the larynx and mandible precedes that at the adductor pollicis. 18 The type and dosage of hypnotics and opioids also influences intubation conditions. 18 We suggest to use objective (and automatic) neuromuscular monitoring with stimulation every 12th second combined with a timer. Laryngoscopy may then be initiated after at least 1.5 minutes and a TOF count of 1 or 0, likely resulting in intubation at TOF count 0. This is debatable.
The US residents used subjective neuromuscular monitoring and clinical tests to assess for readiness for extubation or need for reversal. The limitations of subjective neuromuscular monitoring to detect residual block has been established and it has therefore been suggested to administer at least a small dose of neostigmine to all patients. 19,20 However, not all residents were aware of this approach.
The clinical tests are also unreliable in assessing readiness for extubation. 21 25 It is not enough, however, just to make objective neuromuscular monitoring available and mandatory. 2 We found that the attitude of both the residents and the attendings influenced the use of neuromuscular monitoring, with many of the residents not appreciating a potential benefit of objective neuromuscular monitoring over subjective. For department culture to change, training in neuromuscular monitoring should be consistent and lead by clinicians with experience using the equipment, and surveys of residual neuromuscular block should be conducted locally to increase awareness. 2,8,9 The interviews with Danish anaesthetists also revealed a need for further training in the purpose of calibration of the objective neuromuscular monitoring device and dealing with TOF ratios >1.0, as was also described in a recent Danish survey. 12 A challenge identified was placing the monitor when the patient's arms were tucked to the sides. Electromyography, as opposed to acceleromyography, could potentially eliminate this challenge because it does not require a freely moving thumb. 2 A further advantage of electromyography would be a control TOF ratio closer to 1.0. 26 We found that even when objective neuromuscular monitoring was available, the residents at the US institution were reluctant to use it, either from lack of training or because they did not find it necessary. In a survey from 2010, US respondents were also less likely to use objective neuromuscular monitoring than European respondents, even if both subjective and objective monitoring were available. 10 Both in Denmark and the US institution, anaesthetists agreed that residual neuromuscular block is a serious complication and that it probably occurs more frequently than experienced. This in concordance with surveys of anaesthesiologists' opinions and attitude about residual neuromuscular block, where the incidence is often underestimated and thought to be higher in colleagues' practices. 6,11,22 In a recent study assessing the incidence of residual neuromuscular block in 10 US hospitals, including the institution studied, 65% of patients receiving a non-depolarizing NMBA had a TOF ratio <0.9 at extubation. 27 Though our study was not quantitatively designed, it is worth noticing that several of the residents at the US institution had experienced cases with severe residual neuromuscular block, including need for re-intubation, already within the first years of training, whereas in Denmark, only senior consultants reported that type of experience.

| Neuromuscular monitoring after succinylcholine
Although patients with undiagnosed BChE deficiency are at high risk of experiencing awareness during emergence if neuromuscular monitoring is not applied, neither Danish anaesthetists nor the residents monitored the depolarizing block routinely. 3 Both Danish and US anaesthetists reported senior colleagues who would not acknowledge residual neuromuscular block due to BChE deficiency, as was also described in a study of cases from the Danish BChE registry. 3

| Strengths and limitations
The

| Implications
While almost fully implemented in Denmark, objective neuromuscular monitoring still poses challenges in daily clinical practice.
Training is needed in troubleshooting the potential pitfalls that exist with these devices which are not described in standard anaesthesia textbooks. Continuing medical education in this topic could include e-learning modules that can easily be disseminated to a larger audience. 28 In US institutions that aim to implement objective neuromuscular monitoring, residents should be motivated to use the equipment not only by the reduction of residual neuromuscular block and postoperative pulmonary complications, but also the potential to simplify assessment of need for reversal and readiness for extubation. There is still a need for a culture change, also among senior anaesthesiologists, putting an end to the incorrect belief that they can rely on subjective neuromuscular monitoring to rule out residual neuromuscular block. 29 The US institution studied is in the process of implementing objective neuromuscular monitoring, bearing the described barriers in mind, and has developed a CME accredited e-learning module about objective neuromuscular monitoring and residual neuromuscular blockade.

| CON CLUS ION
Using qualitative methods, we found that though Danish anaesthetists generally apply objective neuromuscular monitoring routinely and residents at the US institution often apply subjective neuromuscular monitoring, barriers to consistent and correct use still exist.
They include unreliable equipment, time pressure, need for training, misconceptions about NMBA pharmacokinetics and residual block, lack of standards and guidelines and departmental culture.