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.

Early differential diagnosis of ankylosing spondylitis among patients with low back pain in primary care.

Diagnosing and treating low back pain (LBP) is a worldwide major primary care challenge in which a differential diagnosis between non-specific LBP and conditions with a known pathology is essential for choosing the optimal treatment strategy. The time required for the diagnosis of a condition such as ankylosing spondylitis (AS) was previously found too long. However, a recently published paper by Bashir et al. found that distinct episodes of axial pain separated by more than 6 months seem more predictive than currently applied characteristics in reaching an early diagnosis of AS.

Supraglottic airway devices in difficult airway management: a retrospective cohort study of 658,104 general anaesthetics registered in the Danish Anaesthesia Database.

Indications for using supraglottic airway devices have widened over time and they now hold a prominent role in guidelines for difficult airway management. We aimed to describe the use of supraglottic airway devices in difficult airway management. We included adult patients undergoing general anaesthesia registered in the Danish Anaesthesia Database from 2008 to 2012 whose airway management had been recorded as difficult, defined as: ≥ 3 tracheal intubation attempts; failed tracheal intubation; or difficult facemask ventilation. In the Danish Anaesthesia Database, a separate difficult airway management module requires the technique used in each successive airway management attempt to be recorded. The primary aim of the study was to describe the use of supraglottic airway devices in cases of difficult airway management. Secondary aims were to examine success rates of supraglottic airway devices in difficult airway management cases, and specifically in the cases of 'cannot intubate, cannot facemask ventilate'. Difficult airway management occurred in 4898 (0.74% (95%CI 0.72-0.76%)) of 658,104 records of general anaesthesia. Supraglottic airway devices were used or use was attempted in 607 cases of difficult airway management (12.4% (95%CI 11.5-13.3%)), and were successful in 395 (65.1% (95%CI 61.2-68.8%)) cases. In 'cannot intubate, cannot facemask ventilate' situations, supraglottic airway devices were used in 86 (18.9% (95%CI 15.6-22.8%)) of 455 records and were successful in 54 (62.8% (95%CI 52.2-72.3%)) cases. We found that supraglottic airway devices are not widely used in the management of the difficult airway despite their prominent role in difficult airway management guidelines.

Effects of avoidance or use of neuromuscular blocking agents on outcomes in tracheal intubation: a Cochrane systematic review.

Cohort studies have indicated that avoidance of neuromuscular blocking agents (NMBA) is a risk factor for difficult tracheal intubation. However, the impact of avoiding NMBA on tracheal intubation, possible adverse effects, and postoperative discomfort has not been evaluated in a systematic review of randomised trials. We searched several databases for trials published until January 2017. We included randomised controlled trials comparing the effect of avoiding vs using NMBA. Two independent authors assessed risk of bias and extracted data. The risk of random errors was assessed by trial sequential analysis (TSA). We included 34 trials (3565 participants). In the four trials judged to have low risk of bias, there was an increased risk of difficult tracheal intubation with no use of NMBA [random-effects model, risk ratio (RR) 13.27, 95% confidence interval (CI) 8.19-21.49, P<0.00001, TSA-adjusted CI 1.85-95.04]. The result was confirmed when including all trials, (RR 5.00, 95% CI 3.49-7.15, P<0.00001, TSA-adjusted CI 1.20-20.77). There was a significant risk of upper airway discomfort or injury by avoiding NMBA (RR=1.37, 95% CI 1.09-1.74, P=0.008, TSA-adjusted CI 1.00-1.86). None of the trials reported mortality. Avoiding NMBA was significantly associated with difficult laryngoscopy, (RR 2.54, 95% CI 1.53-4.21, P=0.0003, TSA-adjusted CI 0.27-21.75). In a clinical context, one must balance arguments for using NMBA when performing tracheal intubation.

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.

Prediction of difficult mask ventilation using a systematic assessment of risk factors vs. existing practice - a cluster randomised clinical trial in 94,006 patients.

We compared implementation of systematic airway assessment with existing practice of airway assessment on prediction of difficult mask ventilation. Twenty-six departments were cluster-randomised to assess eleven risk factors for difficult airway management (intervention) or to continue with their existing airway assessment (control). In both groups, patients predicted as a difficult mask ventilation and/or difficult intubation were registered in the Danish Anaesthesia Database, with a notational summary of airway management. The trial's primary outcome was the respective incidence of unpredicted difficult and easy mask ventilation in the two groups. Among 94,006 patients undergoing mask ventilation, the incidence of unpredicted difficult mask ventilation in the intervention group was 0.91% and 0.88% in the control group; (OR) 0.98 (95% CI 0.66-1.44), p = 0.90. The incidence of patients predicted difficult to mask ventilate, but in fact found to be easy ('falsely predicted difficult') was 0.64% vs. 0.35% (intervention vs. control); OR 1.56 (1.01-2.42), p = 0.045. In the intervention group, 86.3% of all difficult mask ventilations were not predicted, compared with a higher proportion 91.2% in the control group, OR 0.61 (0.41-0.91), p = 0.016. The systematic intervention did not alter the overall incidence of unpredicted difficult mask ventilations, but of the patients who were found to be difficult to mask ventilate, the proportion predicted was higher in the intervention group than in the control group. However, this was at a 'cost' of increasing the number of mask ventilations falsely predicted to be difficult.

Effects of using the simplified airway risk index vs usual airway assessment on unanticipated difficult tracheal intubation - a cluster randomized trial with 64,273 participants.

BACKGROUND: Unanticipated difficult intubation remains a challenge in anaesthesia. The Simplified Airway Risk Index (SARI) is a multivariable risk model consisting of seven independent risk factors for difficult intubation. Our aim was to compare preoperative airway assessment based on the SARI with usual airway assessment. METHODS: From 01.10.2012 to 31.12.2013, 28 departments were cluster-randomized to apply the SARI model or usual airway assessment. The SARI group implemented the SARI model. The Non-SARI group continued usual airway assessment, thus reflecting a group of anaesthetists' heterogeneous individual airway assessments. Preoperative prediction of difficult intubation and actual intubation difficulties were registered in the Danish Anaesthesia Database for both groups. Patients who were preoperatively scheduled for intubation by advanced techniques (e.g. video laryngoscopy; flexible optic scope) were excluded from the primary analysis. Primary outcomes were the proportions of unanticipated difficult and unanticipated easy intubation. RESULTS: A total of 26 departments (15 SARI and 11 Non-SARI) and 64 273 participants were included. In the primary analyses 29 209 SARI and 30 305 Non-SARI participants were included.In SARI departments 2.4% (696) of the participants had an unanticipated difficult intubation vs 2.4% (723) in Non-SARI departments. Odds ratio (OR) adjusted for design variables was 1.03 (95% CI: 0.77-1.38). The proportion of unanticipated easy intubation was 1.42% (415) in SARI departments vs 1.00% (302) in Non-SARI departments. Adjusted OR was 1.26 (0.68-2.34). CONCLUSIONS: Using the SARI compared with usual airway assessment we detected no statistical significant changes in unanticipated difficult- or easy intubations. CLINICAL TRIAL REGISTRATION: NCT01718561.

Premature awakening and underuse of neuromuscular monitoring in a registry of patients with butyrylcholinesterase deficiency.

BACKGROUND: Patients with butyrylcholinesterase (BChE) deficiency can experience prolonged paralysis after receiving suxamethonium or mivacurium. We hypothesized that patients suspected of BChE deficiency had a higher risk of being awakened while paralysed and having respiratory complications if neuromuscular monitoring was not applied before awakening. METHODS: We retrospectively included patients referred to the Danish Cholinesterase Research Unit between 2004 and 2012 on suspicion of BChE deficiency. We collected data on genotype, BChE activity, neuromuscular blocking agents administered, neuromuscular monitoring, and postoperative respiratory complications, defined as arterial oxygen desaturation <90%, assisted ventilation, reintubation of the trachea, and pulmonary aspiration. Patients were classified as prematurely awakened if anaesthesia had been terminated while the patient was still paralysed. RESULTS: We included 123 patients. Neuromuscular monitoring was applied before awakening in 48 (39%) patients. A nerve stimulator was never used or only after attempted awakening in the remaining 75 (61%) patients. Premature awakening occurred in 75 (100%) and 14 (29%) of the unmonitored and monitored patients, respectively (P<0.001, Fisher's exact test). In 11 of the monitored patients, the results of neuromuscular monitoring were interpreted as equipment failure or were disregarded. Respiratory complications occurred in 19 (25%) and five (10%) of the unmonitored and monitored patients, respectively (P=0.06). CONCLUSIONS: Patients with BChE deficiency are at higher risk of being awakened while paralysed if neuromuscular monitoring is not applied or used; neuromuscular monitoring is recommended whenever a neuromuscular blocking agent is administered.

Awareness during emergence from anaesthesia: significance of neuromuscular monitoring in patients with butyrylcholinesterase deficiency.

BACKGROUND: Butyrylcholinesterase deficiency can result in prolonged paralysis after administration of succinylcholine or mivacurium. We conducted an interview study to assess whether patients with butyrylcholinesterase deficiency were more likely to have experienced awareness during emergence from anaesthesia if neuromuscular monitoring had not been applied. METHODS: Patients referred during 2004-2012 were included. Data on the use of neuromuscular monitoring were available from a previous study. Interviews, conducted by telephone, included questions about awareness and screening for post-traumatic stress disorder. Reports of panic, hopelessness, suffocation, or a feeling of being dead or dying resulted in the experience being classified further as distressful. Patients were categorized as aware or unaware by investigators blinded to use of neuromuscular monitoring. RESULTS: Ninety-five patients were eligible to be interviewed. Of the 70 patients interviewed, 35 (50%) were aware while paralysed during emergence. Of these, 28 (80%) were not monitored with a nerve stimulator when awakened, compared with 17 (49%) of the 35 unaware patients (P=0.012, Fisher's exact test). Thirty (86%) aware patients reported distress compared with seven (20%) unaware patients (P<0.001). The aware patients scored higher in screening for post-traumatic stress disorder (P=0.006, Mann-Whitney U-test). CONCLUSIONS: Butyrylcholinesterase deficiency is a major risk factor for distressing awareness during emergence. Lack of neuromuscular monitoring increases the risk significantly. Neuromuscular monitoring should be applied even when using short-acting neuromuscular blocking agents.

The role of the pathologist in human rights abuses.

The objective and unbiased statement is much valued in international work against human rights abuses. Pathologists play an increasingly important role. In this article, this role is illustrated by examples and the international set of rules is described. It is emphasised that under no circumstances should physicians assist in procedures, such as torture, which can weaken a human being. There is ongoing research into the sequelae of torture, both by gross and microscopic examination and in the living and dead victims.

ARDS after accidental inhalation of zinc chloride smoke.

Five soldiers were injured by inhalation of hexite smoke (ZnCl2) during military training. Two soldiers, not wearing gas masks breathed hexite for 1 or 2 min, they slowly developed severe adult respiratory distress syndrome (ARDS) over the ensuing 2 weeks. This slow, progressive clinical course has not been previously described. In both patients, an increased plasma zinc concentration was measured 3 weeks after the incident. Intravenous and nebulized acetylcysteine increased the urinary excretion of zinc, and briefly decreased the plasma levels. In an attempt to arrest collagen deposition in the lungs, L-3,4 dehydroproline was administered. Both patients died of severe respiratory failure (25 and 32 days after inhalation). At autopsy diffuse microvascular obliteration, widespread occlusion of the pulmonary arteries and extensive interstitial and intra-alveolar fibrosis was observed. Three soldiers wearing ill fitting gas masks, immediately developed severe coughing and dyspnea. They improved, and 12 months after exposure their lung function tests were nearly normal, but they still had slight dyspnea on exercise.

Endothelin-1 (ET-1)-potentiated insulin secretion: involvement of protein kinase C and the ET(A) receptor subtype.

Endothelin-1 (ET-1), a potent vasoconstrictor peptide of endothelial origin, is capable of influencing hormone secretion from endocrine tissues, eg, pancreatic islet cells. We have shown a direct stimulatory effect of ET-1 on insulin secretion from isolated mouse islets of Langerhans. However, it is unknown as to whether the peptide acts through specific receptors on the islet cells and which mechanisms are involved in this insulinotropic action. We have therefore used the specific ET(A) receptor antagonist BQ123, the ET(B) receptor agonist BQ3020, and classic alpha- and beta-adrenergic and cholinergic antagonists. ET-1 (100 nmol/L) stimulated insulin secretion from islets incubated at 8.3, 11.1, 16.7, and 25 mmol/L glucose (P < .05). At 3.3 mmol/L glucose, no alteration in insulin secretion was found. The cholinergic receptor antagonist atropine (5 micromol/L) or the adrenergic receptor antagonists propranolol (5 micromol/L) or phentolamine (5 micromol/L) did not affect ET-1 (100 nmol/L)-stimulated insulin secretion. BQ123 (10 pmol/L to 10 nmol/L) and BQ3020 (1 nmol/L to 1 micromol/L) had no effect on glucose (16.7 mmol/L)-stimulated insulin secretion, but BQ123 counteracted the stimulatory effect of ET-1 (100 nmol/L) at concentrations of 1 nmol/L to 10 micromol/L (P < .01). We also studied the relative role of protein kinase C (PKC) and a Wortmannin-sensitive pathway for ET-1-induced insulin secretion using 12-O-tetradecanoyl phorbol-13-acetate (TPA), Calphostin C, and Wortmannin, respectively. At 5.6 mmol/L glucose, ET-1 (100 nmol/L) had no effect per se, whereas in the presence of 1 micromol/L TPA, which acutely stimulates PKC, the peptide did potentiate insulin secretion (P < .05). Furthermore, the insulinotropic effect of ET-1 at 16.7 mmol/L glucose was counteracted by the PKC inhibitor Calphostin C (P < .05) and by downregulation of PKC by 24 hours of exposure of islets to TPA (0.5 micromol/L, P < .05). Wortmannin (1 micromol/L) did not alter ET-1-potentiated insulin secretion. In conclusion, our results suggest that ET-1 acts through specific ET-1 receptors, most likely the ETA subtype. Furthermore, PKC plays an essential role in the insulinotropic action of ET-1 in mouse islets.

Differential effects of cis and trans fatty acids on insulin release from isolated mouse islets.

In vitro and in vivo studies in animals have shown that elevated levels of free fatty acids (FFAs) induce impaired beta-cell function corresponding to the abnormalities observed in non-insulin-dependent diabetes mellitus (NIDDM). Previously, it was demonstrated that the chain length and degree of unsaturation are of importance for the insulinotropic effect of fatty acids. However, it is not known if the spatial configuration of the fatty acid influences beta-cell function. The present study examines whether cis and trans fatty acids acutely influence insulin release and glucose oxidation in isolated mouse islets in the same way and to the same extent. Thus, we studied the impact of both cis and trans forms of C 18:1 fatty acids. We found that cis and trans vaccenic acid (cis and trans C 18:1 delta11), as well as oleic acid (cis C 18:1 delta9) and elaidic acid (trans 18:1 delta9), caused a dose-dependent increase in glucose (16.7 mmol/L)-stimulated insulin secretion during static islet incubations. The maximal stimulatory effect for cis and trans vaccenic acid and for oleic and elaidic acid was observed at concentrations of 2.0 and 3.0 mmol/L, respectively. The trans isomers, trans vaccenic and elaidic acid, elicited a higher maximal insulin output than the respective cis isomers, cis vaccenic and oleic acid. In the presence of another insulin secretagogue, L-leucine, trans vaccenic but not elaidic acid caused a higher response than their cis isomeric fatty acids. The higher potency of trans fatty acids compared with the cis forms was confirmed in perifusion experiments. Both cis and trans C 18:1 fatty acids stimulated insulin secretion in a glucose-dependent manner. Also, glucose oxidation was influenced differentially by the isomers of fatty acids. Glucose oxidation at 16.7 mmol/L glucose was significantly inhibited by oleic and cis vaccenic acid compared with elaidic and trans vaccenic acid, respectively. In summary, our results demonstrate that the fatty acid spatial configuration modulates glucose oxidation and insulin secretion in mouse beta cells.

Various mechanisms of death and their possible association with alcoholism.

Alcoholics who died because they were run over by trains, by precipitation, or were smoking in bed, were compared with a group of controls. A higher number of alcoholics were run over by trains, the manner of death most often being suicide. There was a significantly higher number of controls who fell from a height. The manner of death in the group "smoking in bed' was more often accidental and occurred more frequently in alcoholics. Preventive measures are suggested.

Atherosclerosis in alcoholics.

A cohort of alcoholics who underwent a medico-legal autopsy during a 5-year period was compared with non-alcoholic controls who did not differ from the alcoholics in selection criteria. The degree of atherosclerosis in the coronary arteries and the aorta was examined. Alcoholic men and old women had a significantly lower degree of atherosclerosis in the coronary arteries, while the opposite was found in young women. In the aorta there was no significant difference in the degree of atherosclerosis between alcoholics and controls in men. Alcoholic women generally had a lower degree of atherosclerosis in the aorta. The so-called U-shaped curve for the relationship between the daily alcohol intake and atherosclerosis is described together with some of the investigations on which it is based. There is much positive evidence for the U-shaped curve, although a causal association has not been proven as yet. The present results indicate a complex relationship, in which different confounding factors are likely to play a role.

Significance of various analytical methods with reference to the causes and manners of death in alcoholics.

It was the aim of the present investigation to apply a broad spectrum of analyses to forensic autopsies of alcoholics in order to estimate the significance of the various analytical methods with reference to the cause and manner of death. The analyses were performed on a consecutive series of 73 medico-legal autopsies in alcoholics. Both extensive histology as well as toxicology and microbiology were used. The microbiology did not contribute substantially to the determination of the cause of death, while histology was decisive in six cases. Toxicology analyses were necessary for determining the cause of death in 37 cases. The results of the investigation may help in the selection of analytical priorities.

The effect of temperature on Y-chromosome detection in blood stains.

The present investigation is an extension of an earlier work on the effect of various temperatures on Y-chromosome detection. The deteriorating effect of storage at 53 degrees C was again demonstrated. Liquid blood samples stored at 5 degrees C were better preserved with regard to Y-chromosomes than those stored at room temperature. This was in conflict with the earlier results on blood stains. New experiments were therefore performed. The results varied. It is suggested that this variation was due to low temperatures having two contrary effects on the results: the well-known preserving effect on biological material and a previously described constricting effect on the heterochromatic areas of the chromosomes making Y-body detection more difficult.