A retrospective observational study of neuromuscular monitoring practice in 30,430 cases from six Danish hospitals.

Timely application of objective neuromuscular monitoring can avoid residual neuromuscular blockade. We assessed the frequency of objective neuromuscular monitoring with acceleromyography and the last recorded train-of-four ratio in a cohort of Danish patients. We extracted data from all patients receiving general anaesthesia from November 2014 to November 2016 at six hospitals in the Zealand Region of Denmark. Acceleromyography was available in all operating rooms and data were recorded automatically. The primary outcome measure was acceleromyography use in patients receiving neuromuscular blocking agents, divided into non-depolarising agents and succinylcholine only. The dataset included 76,743 cases, of which 30,430 received a neuromuscular blocking drug. Non-depolarising drugs were used in 16,525 (54%) and succinylcholine as the sole drug in 13,905 (46%) cases. Acceleromyography was used in 14,463 (88%) patients who received a non-depolarising neuromuscular blocking drug and in 4224 (30%) receiving succinylcholine alone. Acceleromyography use varied between the departments from 58% to 99% for non-depolarising drugs and from 3% to 79% for succinylcholine alone. The median (IQR [range]) of the last recorded train-of-four ratio before tracheal extubation was 0.97 (0.90-1.06 [0.01-2.20]) when non-depolarising drugs were used, and was less than 0.9 in 22% of cases. The OR for oxygen desaturation was higher with the use of succinylcholine [2.51 (95%CI 2.33-2.70) p < 0.001] and non-depolarising drugs [2.57 (95%CI 2.32-2.84) p < 0.001] as compared with cases where no neuromuscular blockade drug was used. In conclusion, acceleromyography was almost always used in cases where non-depolarising neuromuscular blocking drugs were used, but a train-of-four ratio of 0.9 was not always achieved. Monitoring was used in less than 30% of cases where succinylcholine was the sole drug used.

Validation of subjective rating scales for assessment of surgical workspace during laparoscopy.

BACKGROUND: Recently, studies have focused on how to optimize laparoscopic surgical workspace by changes in intra-abdominal pressure, level of muscle relaxation or body position, typically evaluated by surgeons using subjective rating scales. We aimed to validate two rating scales by having surgeons assess surgical workspace in video sequences recorded during laparoscopic surgery. METHOD: Video sequences were obtained from laparoscopic procedures. Eight experienced surgeons assessed the video sequences on a categorical 5-point scale and a numerical 10-point rating scale. Intraclass correlations coefficients (ICC) and 95% confidence intervals (CI) were calculated for intra- and inter-rater reliability. RESULTS: The 5-point rating scale had an intra-rater ICC of 0.76 (0.69; 0.83) and an inter-rater ICC of 0.57 (0.45; 0.68), corresponding to excellent and fair reliability, respectively. The 10-point scale had an intra-rater ICC of 0.86 (0.82; 0.89) and an inter-rater ICC of 0.54 (0.39; 0.68), corresponding to excellent and fair as well. All surgeons used the full range of the 5-point scale, but only one surgeon used the full range of the 10-point scale. CONCLUSION: In conclusion, both scales showed excellent intra-rater and fair inter-rater reliability for assessing surgical workspace in laparoscopy. The 5-point surgical rating scale had all categories employed by all surgeons.

High intraoperative inspiratory oxygen fraction and risk of major respiratory complications.

BACKGROUND: High inspiratory oxygen fraction ( FIO2 ) may improve tissue oxygenation but also impair pulmonary function. We aimed to assess whether the use of high intraoperative FIO2 increases the risk of major respiratory complications. METHODS: We studied patients undergoing non-cardiothoracic surgery involving mechanical ventilation in this hospital-based registry study. The cases were divided into five groups based on the median FIO2 between intubation and extubation. The primary outcome was a composite of major respiratory complications (re-intubation, respiratory failure, pulmonary oedema, and pneumonia) developed within 7 days after surgery. Secondary outcomes included 30-day mortality. Several predefined covariates were included in a multivariate logistic regression model. RESULTS: The primary analysis included 73 922 cases, of whom 3035 (4.1%) developed a major respiratory complication within 7 days of surgery. For patients in the high- and low-oxygen groups, the median FIO2 was 0.79 [range 0.64-1.00] and 0.31 [0.16-0.34], respectively. Multivariate logistic regression analysis revealed that the median FIO2 was associated in a dose-dependent manner with increased risk of respiratory complications (adjusted odds ratio for high vs low FIO2 1.99, 95% confidence interval [1.72-2.31], P -value for trend <0.001). This finding was robust in a series of sensitivity analyses including adjustment for intraoperative oxygenation. High median FIO2 was also associated with 30-day mortality (odds ratio for high vs low FIO2 1.97, 95% confidence interval [1.30-2.99], P -value for trend <0.001). CONCLUSIONS: In this analysis of administrative data on file, high intraoperative FIO2 was associated in a dose-dependent manner with major respiratory complications and with 30-day mortality. The effect remained stable in a sensitivity analysis controlled for oxygenation. CLINICAL TRIAL REGISTRATION: NCT02399878.

Objective neuromuscular monitoring of neuromuscular blockade in Denmark: an online-based survey of current practice.

BACKGROUND: Neuromuscular blocking agents are commonly used during general anaesthesia but can lead to postoperative residual neuromuscular blockade and associated morbidity. With appropriate objective neuromuscular monitoring (objNMM) residual blockade can be avoided. In this survey, we investigated the use of objNMM in Denmark. METHODS: We conducted an anonymous Internet-based survey distributed through e-mails to Danish public anaesthesia departments. The survey consisted of 15-17 short questions regarding the use of objNMM. RESULTS: A total of 653 (27%) anaesthetists from 90% of the hospitals answered the questionnaire. ObjNMM was always used by 58% of the anaesthetists and 86% used objNMM at least 75% of the times. Despite the frequent use, 75% of the anaesthetists experienced difficulties with objNMM in at least 25% of the cases. The likelihood of using objNMM was higher among nurse anaesthetists vs. anaesthesiologists (odds ratio (OR) 2.24 [95% confidence interval (CI): 1.62-3.08]), if the department had an employee with special interest in objNMM (OR 1.66 [95% CI: 1.12-2.47]), if the anaesthetist had < 5 years of experience (OR 1.88 [95% CI: 1.29-2.73]), or if experiencing difficulties with objNMM < 25% of the cases (OR 1.60 [95% CI: 1.00-2.57]). CONCLUSION: In this survey, Danish anaesthetists frequently, in an international perspective, use objNMM, but the use is often associated with technical difficulties.

Is deep neuromuscular blockade beneficial in laparoscopic surgery? Yes, probably.

BACKGROUND: Deep neuromuscular blockade during laparoscopic surgery may provide some clinical benefit. We present the 'Pro-' argument in this paired position paper. METHODS: We reviewed recent evidence from a basic database of references which we agreed on with the 'Con-' side, and present this in narrative form. We have shared our analysis and text with the authors of the 'Con-' side of these paired position papers during the preparation of the manuscripts. RESULTS: There are a few low risk of bias studies indicating that use of deep neuromuscular blockade improve surgical conditions and improve patient outcomes such as post-operative pain in laparoscopic surgery. CONCLUSION: Our interpretation of recent findings is that there is reason to believe that there may be some patient benefit of deep neuromuscular blockade in this context, and more detailed study is needed.

Impaired postural stability after laparoscopic surgery.

BACKGROUND: Early postoperative mobilisation may reduce patient morbidity and improve hospital efficiency by accelerated discharge. The aim of this study was to measure postural stability early after laparoscopic surgery in order to assess how early it is safe to mobilise and discharge patients. METHODS: We included 25 women undergoing outpatient gynaecological laparoscopic surgery in the study. Patients received standardised anaesthesia with propofol, remifentanil and rocuronium. Postural stability was assessed preoperatively, at 30 min after tracheal extubation, and at discharge from the post-anaesthesia care unit using a force platform where sway area, mean sway and sway velocity were determined. The assessments were done with eyes closed and with eyes open. The primary outcome was the change in sway area with eyes closed 30 min after extubation. Data are reported as median (25-75% range). RESULTS: Three patients could not perform all the test's 30 min after extubation. Thirty minutes after extubation, sway area with eyes closed had increased significantly with 84 mm(2) (9-172, P = 0.011) and 108 mm(2) with eyes open (25-295, P = 0.0017). Median mean sway had also increased significantly 30 min postoperatively. No significant changes were found for sway velocity. We found no significant changes in mean sway, sway area or sway velocity at discharge from the post-anaesthesia care unit approximately 2 h after surgery. CONCLUSION: Postural stability was significantly impaired 30 min after outpatient gynaecological laparoscopic surgery. However, the postural stability was normalised at discharge from the post-anaesthesia care unit 2 h after surgery.

Effects of sugammadex on incidence of postoperative residual neuromuscular blockade: a randomized, controlled study.

BACKGROUND: This study aimed to investigate whether reversal of rocuronium-induced neuromuscular blockade with sugammadex reduced the incidence of residual blockade and facilitated operating room discharge readiness. METHODS: Adult patients undergoing abdominal surgery received rocuronium, followed by randomized allocation to sugammadex (2 or 4 mg kg(-1)) or usual care (neostigmine/glycopyrrolate, dosing per usual care practice) for reversal of neuromuscular blockade. Timing of reversal agent administration was based on the providers' clinical judgement. Primary endpoint was the presence of residual neuromuscular blockade at PACU admission, defined as a train-of-four (TOF) ratio <0.9, using TOF-Watch® SX. Key secondary endpoint was time between reversal agent administration and operating room discharge-readiness; analysed with analysis of covariance. RESULTS: Of 154 patients randomized, 150 had a TOF value measured at PACU entry. Zero out of 74 sugammadex patients and 33 out of 76 (43.4%) usual care patients had TOF-Watch SX-assessed residual neuromuscular blockade at PACU admission (odds ratio 0.0, 95% CI [0-0.06], P<0.0001). Of these 33 usual care patients, 2 also had clinical evidence of partial paralysis. Time between reversal agent administration and operating room discharge-readiness was shorter for sugammadex vs usual care (14.7 vs. 18.6 min respectively; P=0.02). CONCLUSIONS: After abdominal surgery, sugammadex reversal eliminated residual neuromuscular blockade in the PACU, and shortened the time from start of study medication administration to the time the patient was ready for discharge from the operating room. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov:NCT01479764.

Neuromuscular blockade for optimising surgical conditions during abdominal and gynaecological surgery: a systematic review.

BACKGROUND: The level of neuromuscular blockade (NMB) that provides optimal surgical conditions during abdominal surgery has not been well established. The aim of this systematic review was to evaluate current evidence on the use of neuromuscular blocking agents in order to optimise surgical conditions during laparoscopic procedures and open abdominal surgery. METHODS: A wide search was performed in PubMed, Cochrane library and Embase with systematic approach including PRISMA recommendations. Individual risk of bias was assessed and systematic data extraction were performed. RESULTS: Fifteen studies with data from 998 patients were included. There is good evidence that the use of deep NMB compared with moderate NMB is associated with optimised surgical conditions during laparoscopic cholecystectomy, hysterectomy and nephrectomy/prostatectomy. In laparoscopic cholecystectomy during low pressure pneumoperitoneum, deep NMB marginally improves the surgical conditions. However, to ensure acceptable surgical conditions, it may be necessary to increase the intra-abdominal pressure in up to half of the patients regardless of level of NMB. There is good evidence that moderate NMB improves surgical conditions in some cases during open radical retropubic prostatectomy. However, good and excellent surgical conditions may be achievable even without NMB. There is good evidence to recommend deep NMB in laparoscopic cholecystectomy, nephrectomy and prostatectomy to improve surgical conditions. There is insufficient evidence to recommend an ideal level of NMB creating optimal surgical condition during laparotomy. CONCLUSION: Use of deep NMB in certain laparoscopic procedures may improve surgical conditions. In open abdominal surgery, use of NMB may optimise surgical conditions under certain circumstances.

Use of neuromuscular monitoring to detect prolonged effect of succinylcholine or mivacurium: three case reports.

Mutations in the butyrylcholinesterase gene can lead to a prolonged effect of the neuromuscular blocking agents, succinylcholine and mivacurium. If the anaesthesiologist is not aware of this condition, it may result in insufficient respiration after tracheal extubation. However, this can be avoided with the use of objective neuromuscular monitoring if used adequately. Three case reports of prolonged effect of succinylcholine or mivacurium were presented to illustrate the importance of neuromuscular monitoring during anaesthesia. In the first case, continuous intraoperative neuromuscular monitoring allowed a prolonged neuromuscular blockade to be discovered prior to tracheal extubation of the patient. The patient was extubated after successful reversal of the neuromuscular blockade. On the contrary, neuromuscular monitoring was not used during anaesthesia in the second patient; hence, the prolonged effect of the neuromuscular blocking agent was not discovered until after extubation. In the third patient, the lack of response to nerve stimulation was interpreted as a technical failure and the prolonged effect of succinylcholine was discovered when general anaesthesia was terminated. Both patients had insufficient respiration. They were therefore re-sedated, transferred to the intensive care unit and the tracheas were extubated after full recovery from neuromuscular blockade. We recommend the use of monitoring every time these agents are used, even with short-acting drugs like succinylcholine and mivacurium.

Minimal impairment in pulmonary function following laparoscopic surgery.

BACKGROUND: Pulmonary function may be impaired in connection with laparoscopic surgery, especially in the head-down body position, but the clinical importance has not been assessed in detail. The aim of this study was to assess pulmonary function after laparoscopic hysterectomy and laparoscopic cholecystectomy. We hypothesised that arterial oxygenation would be more impaired after hysterectomy performed in the head-down position than after cholecystectomy in the head-up position. METHODS: We included 60 women in this prospective, observational study. The patients underwent elective laparoscopic cholecystectomy in the 20° head-up position or hysterectomy in the 30° head-down position. The primary outcome was the difference between arterial oxygenation (PaO2 ) 2 h postoperatively and the preoperative value. Two hours and 24 h after surgery, pulmonary shunt and ventilation-perfusion mismatch were assessed by use of an automatic lung parameter estimation system. RESULTS: Two hours after surgery, the mean change from baseline in PaO2 was -0.65 kPa [95% confidence interval (CI) -3.5 to 3.4, P = 0.14] in the hysterectomy group and -0.22 kPa [95% CI -3.4 to 2.0, P = 0.12] in the cholecystectomy group (P = 0.88). Shunt was significantly greater in the cholecystectomy group 24 h after surgery compared to the hysterectomy group [4%, 95% CI 0 to 9 vs. 0%, 95% CI 0 to 7, P = 0.02]. CONCLUSIONS: Minimal impairment in pulmonary gas exchange was found after laparoscopic surgery. Pulmonary shunt was larger after laparoscopic cholecystectomy, but no clinically significant differences in postoperative pulmonary gas exchange or spirometry were found between laparoscopic hysterectomy and laparoscopic cholecystectomy.