Recent Submissions

  • Motor unit dysregulation following 15 days of unilateral lower limb immobilisation.

    Inns, Thomas; Bass, Joseph; Hardy, EJO; Wilkinson, Dawn; Stashuk, D; Atherton, P; Philiips, B; Piasecki, M
    KEY POINTS: Muscle mass and function decline rapidly in situations of disuse such as bed rest and limb immobilisation. The reduction in muscle function commonly exceeds that of muscle mass, which may be associated with the dysregulation of neural input to muscle. We have used intramuscular electromyography to sample individual motor unit and near fibre potentials from the vastus lateralis following 15 days of unilateral limb immobilisation. Following disuse, the disproportionate loss of muscle strength when compared to size coincided with suppressed motor unit firing rate. These motor unit adaptations were observed at multiple contraction levels and in the immobilised limb only. Our findings demonstrate neural dysregulation as a key component of functional loss following muscle disuse in humans. ABSTRACT: Disuse atrophy, caused by situations of unloading such as limb immobilisation, causes a rapid yet diverging reduction in skeletal muscle function when compared to muscle mass. While mechanistic insight into the loss of mass is well studied, deterioration of muscle function with a focus towards the neural input to muscle remains underexplored. This study aimed to determine the role of motor unit adaptation in disuse-induced neuromuscular deficits. Ten young, healthy male volunteers underwent 15 days of unilateral lower limb immobilisation with intramuscular electromyography (iEMG) bilaterally recorded from the vastus lateralis (VL) during knee extensor contractions normalised to maximal voluntary contraction (MVC), pre and post disuse. Muscle cross-sectional area was determined by ultrasound. Individual MUs were sampled and analysed for changes in motor unit (MU) discharge and MU potential (MUP) characteristics. VL CSA was reduced by approximately 15% which was exceeded by a two-fold decrease of 31% in muscle strength in the immobilised limb, with no change in either parameter in the non-immobilised limb. Parameters of MUP size were reduced by 11 to 24% with immobilisation, while neuromuscular junction (NMJ) transmission instability remained unchanged, and MU firing rate decreased by 8 to 11% at several contraction levels. All adaptations were observed in the immobilised limb only. These findings highlight impaired neural input following immobilisation reflected by suppressed MU firing rate which may underpin the disproportionate reductions of strength relative to muscle size. Abstract figure legend Ten healthy young males underwent 15 days of unilateral lower limb immobilisation with an irremovable leg brace. Muscle size, strength and neuromuscular characteristics were measured bilaterally. Muscle strength reduced to a greater extent than muscle size in the immobilised leg while remaining unaltered in the non-immobilised leg. Motor unit firing rate, measured bilaterally using intramuscular electromyography, was also reduced in the immobilised leg only. This occurred at contraction intensities both relative to follow-up muscle strength and muscle strength normalised to pre-immobilisation. These findings suggest that neural dysregulation contributes to the loss of muscle strength observed in situations of disuse atrophy in humans. This article is protected by copyright. All rights reserved.
  • The time course of disuse muscle atrophy of the lower limb in health and disease.

    Hardy, E; Inns, Thomas; Hatt, Jacob; Doleman, Brett; Bass, Joseph; Atherton, P; Lund, Jonathan; Phillips, Bethan
    Short, intermittent episodes of disuse muscle atrophy (DMA) may have negative impact on age related muscle loss. There is evidence of variability in rate of DMA between muscles and over the duration of immobilization. As yet, this is poorly characterized. This review aims to establish and compare the time-course of DMA in immobilized human lower limb muscles in both healthy and critically ill individuals, exploring evidence for an acute phase of DMA and differential rates of atrophy between and muscle groups. MEDLINE, Embase, CINHAL and CENTRAL databases were searched from inception to April 2021 for any study of human lower limb immobilization reporting muscle volume, cross-sectional area (CSA), architecture or lean leg mass over multiple post-immobilization timepoints. Risk of bias was assessed using ROBINS-I. Where possible meta-analysis was performed using a DerSimonian and Laird random effects model with effect sizes reported as mean differences (MD) with 95% confidence intervals (95% CI) at various time-points and a narrative review when meta-analysis was not possible. Twenty-nine studies were included, 12 in healthy volunteers (total n = 140), 18 in patients on an Intensive Therapy Unit (ITU) (total n = 516) and 3 in patients with ankle fracture (total n = 39). The majority of included studies are at moderate risk of bias. Rate of quadriceps atrophy over the first 14 days was significantly greater in the ITU patients (MD -1.01 95% CI -1.32, -0.69), than healthy cohorts (MD -0.12 95% CI -0.49, 0.24) (P < 0.001). Rates of atrophy appeared to vary between muscle groups (greatest in triceps surae (-11.2% day 28), followed by quadriceps (-9.2% day 28), then hamstrings (-6.5% day 28), then foot dorsiflexors (-3.2% day 28)). Rates of atrophy appear to decrease over time in healthy quadriceps (-6.5% day 14 vs. -9.1% day 28) and triceps surae (-7.8% day 14 vs. -11.2% day 28), and ITU quadriceps (-13.2% day 7 vs. -28.2% day 14). There appears to be variability in the rate of DMA between muscle groups, and more rapid atrophy during the earliest period of immobilization, indicating different mechanisms being dominant at different timepoints. Rates of atrophy are greater amongst critically unwell patients. Overall evidence is limited, and existing data has wide variability in the measures reported. Further work is required to fully characterize the time course of DMA in both health and disease.
  • Curcumin Enhances Fed-State Muscle Microvascular Perfusion but Not Leg Glucose Uptake in Older Adults.

    Sian, Tanvir; Lund, Jonathan; Williams, John P
    Therapeutic interventions aimed at enhancing blood flow may combat the postprandial vascular and metabolic dysfunction that manifests with chronological ageing. We compared the effects of acute curcumin (1000 mg) coupled with an oral nutritional supplement (ONS, 7.5 g protein, 24 g carbohydrate and 6 g fat) versus a placebo and ONS (control) on cerebral and leg macrovascular blood flow, leg muscle microvascular blood flow, brachial artery endothelial function, and leg insulin and glucose responses in healthy older adults (n = 12, 50% male, 73 ± 1 year). Curcumin enhanced m. tibialis anterior microvascular blood volume (MBV) at 180 and 240 min following the ONS (baseline: 1.0 vs. 180 min: 1.08 ± 0.02, p = 0.01 vs. 240 min: 1.08 ± 0.03, p = 0.01), and MBV was significantly higher compared with the control at both time points (p < 0.05). MBV increased from baseline in the m. vastus lateralis at 240 min after the ONS in both groups (p < 0.05), and there were no significant differences between groups. Following the ONS, leg blood flow and leg vascular conductance increased, and leg vascular resistance decreased similarly in both conditions (p < 0.05). Brachial artery flow-mediated dilation and middle cerebral artery blood flow were unchanged in both conditions (p > 0.05). Similarly, the curcumin and control groups demonstrated comparable increases in glucose uptake and insulin in response to the ONS. Thus, acute curcumin supplementation enhanced ONS-induced increases in m. tibialis anterior MBV without potentiating m. vastus lateralis MBV, muscle glucose uptake, or systemic endothelial or macrovascular function in healthy older adults.
  • Short-Term, Equipment-Free High Intensity Interval Training Elicits Significant Improvements in Cardiorespiratory Fitness Irrespective of Supervision in Early Adulthood.

    Doleman, Brett (2021-07)
    Introduction: Serious health implications from having low levels of cardiorespiratory fitness (CRF) and being overweight in young adulthood are carried forward into later life. High-intensity interval training (HIIT) is a time-effective, potent stimulus for improving CRF and indices of cardiometabolic health. To date, few studies have investigated the use of equipment-free HIIT or the impact of supervision for improving CRF via HIIT. Methods: Thirty healthy young adults (18-30 y) were randomised to 4 weeks (12 sessions) equipment-free, bodyweight based supervised laboratory HIIT (L-HIIT), unsupervised home HIIT (H-HIIT) or no-intervention (CON). Utilised exercises were star jumps, squats and standing sprints. Measurements of CRF (anaerobic threshold (AT) and VO2peak), blood pressure (BP), body mass index (BMI), blood glucose and plasma insulin by oral glucose tolerance test (OGTT), and muscle architecture were performed at baseline and after the intervention. Results: When compared to the control group, both HIIT protocols improved CRF (AT: L-HIIT mean difference compared to the control group (MD) +2.1 (95% CI: 0.34-4.03) ml/kg/min; p = 0.02; H-HIIT MD +3.01 (1.17-4.85) ml/kg/min; p = 0.002), VO2peak: L-HIIT (MD +2.94 (0.64-5.25) ml/kg/min; p = 0.01; H-HIIT MD +2.55 (0.34-4.76) ml/kg/min; p = 0.03), BMI (L-HIIT MD -0.43 (-0.86 to 0.00) kg/m2; p = 0.05; H-HIIT: MD -0.51 (-0.95 to -0.07) kg/m2; p = 0.03) and m. vastus lateralis pennation angle (L-HIIT MD 0.2 (0.13-0.27)°; p < 0.001; H-HIIT MD 0.17 (0.09 to 0.24)°; p < 0.001). There was no significant change in BP, blood glucose or plasma insulin in any of the groups. Conclusions: Four weeks time-efficient, equipment-free, bodyweight-based HIIT is able to elicit improvements in CRF irrespective of supervision status. Unsupervised HIIT may be a useful tool for counteracting the rise of sedentary behaviours and consequent cardiometabolic disorders in young adults.
  • Atrophy Resistant vs. Atrophy Susceptible Skeletal Muscles: "aRaS" as a Novel Experimental Paradigm to Study the Mechanisms of Human Disuse Atrophy.

    Hardy, EJO
    OBJECTIVE: Disuse atrophy (DA) describes inactivity-induced skeletal muscle loss, through incompletely defined mechanisms. An intriguing observation is that individual muscles exhibit differing degrees of atrophy, despite exhibiting similar anatomical function/locations. We aimed to develop an innovative experimental paradigm to investigate Atrophy Resistant tibialis anterior (TA) and Atrophy Susceptible medial gastrocnemius (MG) muscles (aRaS) with a future view of uncovering central mechanisms. METHOD: Seven healthy young men (22 ± 1 year) underwent 15 days unilateral leg immobilisation (ULI). Participants had a single leg immobilised using a knee brace and air-boot to fix the leg (75° knee flexion) and ankle in place. Dual-energy X-ray absorptiometry (DXA), MRI and ultrasound scans of the lower leg were taken before and after the immobilisation period to determine changes in muscle mass. Techniques were developed for conchotome and microneedle TA/MG muscle biopsies following immobilisation (both limbs), and preliminary fibre typing analyses was conducted. RESULTS: TA/MG muscles displayed comparable fibre type distribution of predominantly type I fibres (TA 67 ± 7%, MG 63 ± 5%). Following 15 days immobilisation, MG muscle volume (-2.8 ± 1.4%, p < 0.05) and muscle thickness decreased (-12.9 ± 1.6%, p < 0.01), with a positive correlation between changes in muscle volume and thickness (R2 = 0.31, p = 0.038). Importantly, both TA muscle volume and thickness remained unchanged. CONCLUSION: The use of this unique "aRaS" paradigm provides an effective and convenient means by which to study the mechanistic basis of divergent DA susceptibility in humans, which may facilitate new mechanistic insights, and by extension, mitigation of skeletal muscle atrophy during human DA
  • Recommendations for standards of monitoring during anaesthesia and recovery 2021: Guideline from the Association of Anaesthetists.

    Morris, C
    This guideline updates and replaces the 5th edition of the Standards of Monitoring published in 2015. The aim of this document is to provide guidance on the minimum standards for monitoring of any patient undergoing anaesthesia or sedation under the care of an anaesthetist. The recommendations are primarily aimed at anaesthetists practising in the UK and Ireland, but it is recognised that these guidelines may also be of use in other areas of the world. Minimum standards for monitoring patients during anaesthesia and in the recovery phase are included. There is also guidance on monitoring patients undergoing sedation and during transfer. There are new sections specifically discussing capnography, sedation and regional anaesthesia. In addition, the indications for processed electroencephalogram and neuromuscular monitoring have been updated.
  • Pre-emptive and preventive NSAIDs for postoperative pain in adults undergoing all types of surgery.

    Carrick, Laura
    BACKGROUND: Postoperative pain is a common consequence of surgery and can have many negative perioperative effects. It has been suggested that the administration of analgesia before a painful stimulus may improve pain control. We defined pre-emptive nonsteroidal anti-inflammatories (NSAIDs) as those given before surgery but not continued afterwards and preventive NSAIDs as those given before surgery and continued afterwards. These were compared to a control group given the NSAIDs after surgery instead of before surgery. OBJECTIVES: To assess the efficacy of preventive and pre-emptive NSAIDs for reducing postoperative pain in adults undergoing all types of surgery. SEARCH METHODS: We searched the following electronic databases: CENTRAL, MEDLINE, Embase, AMED and CINAHL (up to June 2020). In addition, we searched for unpublished studies in three clinical trial databases, conference proceedings, grey literature databases, and reference lists of retrieved articles. We did not apply any restrictions on language or date of publication. SELECTION CRITERIA: We included parallel-group randomized controlled trials (RCTs) only. We included adult participants undergoing any type of surgery. We defined pre-emptive NSAIDs as those given before surgery but not continued afterwards and preventive NSAIDs as those given before surgery and continued afterwards. These were compared to a control group given the NSAIDs after surgery instead of before surgery. We included studies that gave the medication by any route but not given on the skin. DATA COLLECTION AND ANALYSIS: We used the standard methods expected by Cochrane, as well as a novel publication bias test developed by our research group. We used GRADE to assess the certainty of the evidence for each outcome. Outcomes included acute postoperative pain (minimal clinically important difference (MCID): 1.5 on a 0-10 scale), adverse events of NSAIDs, nausea and vomiting, 24-hour morphine consumption (MCID: 10 mg reduction), time to analgesic request (MCID: one hour), pruritus, sedation, patient satisfaction, chronic pain and time to first bowel movement (MCID: 12 hours). MAIN RESULTS: We included 71 RCTs. Seven studies are awaiting classification. We included 45 studies that evaluated pre-emptive NSAIDs and 26 studies that evaluated preventive NSAIDs. We considered only four studies to be at low risk of bias for most domains. The operations and NSAIDs used varied, although most studies were conducted in abdominal, orthopaedic and dental surgery. Most studies were conducted in secondary care and in low-risk participants. Common exclusions were participants on analgesic medications prior to surgery and those with chronic pain. Pre-emptive NSAIDs compared to post-incision NSAIDs For pre-emptive NSAIDs, there is probably a decrease in early acute postoperative pain (MD -0.69, 95% CI -0.97 to -0.41; studies = 36; participants = 2032; I2 = 96%; moderate-certainty evidence). None of the included studies that reported on acute postoperative pain reported adverse events as an outcome. There may be little or no difference between the groups in short-term (RR 1.00, 95% CI 0.34 to 2.94; studies = 2; participants = 100; I2 = 0%; low-certainty evidence) or long-term nausea and vomiting (RR 0.85, 95% CI 0.52 to 1.38; studies = 5; participants = 228; I2 = 29%; low-certainty evidence). There may be a reduction in late acute postoperative pain (MD -0.22, 95% CI -0.44 to 0.00; studies = 28; participants = 1645; I2 = 97%; low-certainty evidence). There may be a reduction in 24-hour morphine consumption with pre-emptive NSAIDs (MD -5.62 mg, 95% CI -9.00 mg to -2.24 mg; studies = 16; participants = 854; I2 = 99%; low-certainty evidence) and an increase in the time to analgesic request (MD 17.04 minutes, 95% CI 3.77 minutes to 30.31 minutes; studies = 18; participants = 975; I2 = 95%; low-certainty evidence). There may be little or no difference in opioid adverse events such as pruritus (RR 0.40, 95% CI 0.09 to 1.76; studies = 4; participants = 254; I2 = 0%; low-certainty evidence) or sedation (RR 0.51, 95% CI 0.16 to 1.68; studies = 4; participants = 281; I2 = 0%; low-certainty evidence), although the number of included studies for these outcomes was small. No study reported patient satisfaction, chronic pain or time to first bowel movement for pre-emptive NSAIDs. Preventive NSAIDs compared to post-incision NSAIDs For preventive NSAIDs, there may be little or no difference in early acute postoperative pain (MD -0.14, 95% CI -0.39 to 0.12; studies = 18; participants = 1140; I2 = 75%; low-certainty evidence). One study reported adverse events from NSAIDs (reoperation for bleeding) although the events were low which did not allow any meaningful conclusions to be drawn (RR 1.95; 95% CI 0.18 to 20.68). There may be little or no difference in rates of short-term (RR 1.26, 95% CI 0.49 to 3.30; studies = 1; participants = 76; low-certainty evidence) or long-term (RR 0.85, 95% CI 0.52 to 1.38; studies = 5; participants = 456; I2 = 29%; low-certainty evidence) nausea and vomiting. There may be a reduction in late acute postoperative pain (MD -0.33, 95% CI -0.59 to -0.07; studies = 21; participants = 1441; I2 = 81%; low-certainty evidence). There is probably a reduction in 24-hour morphine consumption (MD -1.93 mg, 95% CI -3.55 mg to -0.32 mg; studies = 16; participants = 1323; I2 = 49%; moderate-certainty evidence). It is uncertain if there is any difference in time to analgesic request (MD 8.51 minutes, 95% CI -31.24 minutes to 48.27 minutes; studies = 8; participants = 410; I2 = 98%; very low-certainty evidence). As with pre-emptive NSAIDs, there may be little or no difference in other opioid adverse events such as pruritus (RR 0.56, 95% CI 0.09 to 3.35; studies = 3; participants = 211; I2 = 0%; low-certainty evidence) and sedation (RR 0.84, 95% CI 0.44 to 1.63; studies = 5; participants = 497; I2 = 0%; low-certainty evidence). There is probably little or no difference in patient satisfaction (MD -0.42; 95% CI -1.09 to 0.25; studies = 1; participants = 72; moderate-certainty evidence). No study reported on chronic pain. There is probably little or no difference in time to first bowel movement (MD 0.00; 95% CI -15.99 to 15.99; studies = 1; participants = 76; moderate-certainty evidence). AUTHORS' CONCLUSIONS: There was some evidence that pre-emptive and preventive NSAIDs reduce both pain and morphine consumption, although this was not universal for all pain and morphine consumption outcomes. Any differences found were not clinically significant, although we cannot exclude this in more painful operations. Moreover, without any evidence of reductions in opioid adverse effects, the clinical significance of these results is questionable although few studies reported these outcomes. Only one study reported clinically significant adverse events from NSAIDs administered before surgery and, therefore, we have very few data to assess the safety of either pre-emptive or preventive NSAIDs. Therefore, future research should aim to adhere to the highest methodology and be adequately powered to assess serious adverse events of NSAIDs and reductions in opioid adverse events.
  • Trainee-led emergency laparotomy operating.

    Boyd-Carson, H; Doleman, Brett; Williams, John P; Tierney, Gillian (2020-04)
    BACKGROUND: To achieve completion of training in general surgery, trainees are required to demonstrate competency in common procedures performed at emergency laparotomy. The aim of this study was to describe the patterns of trainee led emergency laparotomy operating and the association between postoperative outcomes. METHODS: Data on all patients who had an emergency laparotomy between December 2013 and November 2017 were extracted from the National Emergency Laparotomy Audit database. Patients were grouped by grade of operating surgeon: trainee (specialty registrar) or consultant (including post-Certificate of Completion of Training fellows). Trends in trainee operating by deanery, hospital size and time of day of surgery were investigated. Univariable and adjusted regression analyses were performed for the outcomes 90-day mortality and return to theatre, with analysis of patients in operative subgroups segmental colectomy, Hartmann's procedure, adhesiolysis and repair of perforated peptic ulcer disease. RESULTS: The study cohort included 87 367 patients. The 90-day mortality rate was 15•1 per cent in the consultant group compared with 11•0 per cent in the trainee group. There were no increased odds of death by 90 days or of return to theatre across any of the operative groups when the operation was performed with a trainee listed as the most senior surgeon in theatre. Trainees were more likely to operate independently in high-volume centres (highest- versus lowest-volume centres: odds ratio (OR) 2•11, 95 per cent c.i. 1•91 to 2•33) and at night (00.00 to 07.59 versus 08.00 to 11.59 hours; OR 3•20, 2•95 to 3•48). CONCLUSION: There is significant variation in trainee-led operating in emergency laparotomy by geographical area, hospital size and by time of day. However, this does not appear to influence mortality or return to theatre.
  • The efficacy of 'static' training interventions for improving indices of cardiorespiratory fitness in premenopausal females.

    Herrod, Philip; Blackwell, James; Moss, BF; Lund, Jonathan; Williams, John P; Phillips, Bethan (2019-03)
    PURPOSE: Cardiovascular disease (CVD) is the leading cause of death worldwide. Many risk factors for CVD can be modified pharmacologically; however, uptake of medications is low, especially in asymptomatic people. Exercise is also effective at reducing CVD risk, but adoption is poor with time-commitment and cost cited as key reasons for this. Repeated remote ischaemic preconditioning (RIPC) and isometric handgrip (IHG) training are both inexpensive, time-efficient interventions which have shown some promise in reducing blood pressure (BP) and improving markers of cardiovascular health and fitness. However, few studies have investigated the effectiveness of these interventions in premenopausal women. METHOD: Thirty healthy females were recruited to twelve supervised sessions of either RIPC or IHG over 4 weeks, or acted as non-intervention controls (CON). BP measurements, flow-mediated dilatation (FMD) and cardiopulmonary exercise tests (CPET) were performed at baseline and after the intervention period. RESULTS: IHG and RIPC were both well-tolerated with 100% adherence to all sessions. A statistically significant reduction in both systolic (- 7.2 mmHg) and diastolic (- 6 mmHg) BP was demonstrated following IHG, with no change following RIPC. No statistically significant improvements were observed in FMD or CPET parameters in any group. CONCLUSIONS: IHG is an inexpensive and well-tolerated intervention which may improve BP; a key risk factor for CVD. Conversely, our single arm RIPC protocol, despite being similarly well-tolerated, did not elicit improvements in any cardiorespiratory parameters in our chosen population.
  • Why most published meta-analysis findings are false.

    Doleman, Brett; Williams, John P; Lund, Jonathan (2019-06)
  • Cancelled operations: a 7-day cohort study of planned adult inpatient surgery in 245 UK National Health Service hospitals.

    University Hospitals of Derby and Burton (2018-10)
    BACKGROUND: Cancellation of planned surgery impacts substantially on patients and health systems. This study describes the incidence and reasons for cancellation of inpatient surgery in the UK NHS. METHODS: We conducted a prospective observational cohort study over 7 consecutive days in March 2017 in 245 NHS hospitals. Occurrences and reasons for previous surgical cancellations were recorded. Using multilevel logistic regression, we identified patient- and hospital-level factors associated with cancellation due to inadequate bed capacity. RESULTS: We analysed data from 14 936 patients undergoing planned surgery. A total of 1499 patients (10.0%) reported previous cancellation for the same procedure; contemporaneous hospital census data indicated that 13.9% patients attending inpatient operations were cancelled on the day of surgery. Non-clinical reasons, predominantly inadequate bed capacity, accounted for a large proportion of previous cancellations. Independent risk factors for cancellation due to inadequate bed capacity included requirement for postoperative critical care [odds ratio (OR)=2.92; 95% confidence interval (CI), 2.12-4.02; P<0.001] and the presence of an emergency department in the treating hospital (OR=4.18; 95% CI, 2.22-7.89; P<0.001). Patients undergoing cancer surgery (OR=0.32; 95% CI, 0.22-0.46; P<0.001), obstetric procedures (OR=0.17; 95% CI, 0.08-0.32; P<0.001), and expedited surgery (OR=0.39; 95% CI, 0.27-0.56; P<0.001) were less likely to be cancelled. CONCLUSIONS: A significant proportion of patients presenting for surgery have experienced a previous cancellation for the same procedure. Cancer surgery is relatively protected, but bed capacity, including postoperative critical care requirements, are significant risk factors for previous cancellations.
  • Guidelines for the safe practice of total intravenous anaesthesia (TIVA): Joint Guidelines from the Association of Anaesthetists and the Society for Intravenous Anaesthesia.

    Mulvey, David (2018-10)
    Guidelines are presented for safe practice in the use of intravenous drug infusions for general anaesthesia. When maintenance of general anaesthesia is by intravenous infusion, this is referred to as total intravenous anaesthesia. Although total intravenous anaesthesia has advantages for some patients, the commonest technique used for maintenance of anaesthesia in the UK and Ireland remains the administration of an inhaled volatile anaesthetic. However, the use of an inhalational technique is sometimes not possible, and in some situations, inhalational anaesthesia is contraindicated. Therefore, all anaesthetists should be able to deliver total intravenous anaesthesia competently and safely. For the purposes of simplicity, these guidelines will use the term total intravenous anaesthesia but also encompass techniques involving a combination of intravenous infusion and inhalational anaesthesia. This document is intended as a guideline for safe practice when total intravenous anaesthesia is being used, and not as a review of the pros and cons of total intravenous anaesthesia vs. inhalational anaesthesia in situations where both techniques are possible.
  • Beyond the fear of tetanus

    Lee, David; Van Staden, Bernhard; Webb, Carole (2018-07)
    While quoted as 'man's best friend', a commensal found commonly in the oral cavity of dogs can cause fulminant sepsis in humans. Although Clostridium tetani is prominent, few may know about Capnocytophaga carnimorsus. We attended a patient with multi-organ failure, purpuric rash and limb ischaemia resulting in above knee amputations. Description A previously well 62-year-old female presented to the ED shocked with significant metabolic acidosis (pH 6.9 and lactate 20). Of note was rapidly spreading purpura, leading initial suspicion to meningococcal septicaemia. She had crystalloid resuscitation, peripheral vasopressors and central access for noradrenaline. Following ketamine induction she was intubated and transferred to ITU for multi-organ support (included RRT, high inotropic requirements and management of DIC). Two days prior she sustained an apparently trivial dog bite to her finger while separating her dog fighting the pet rabbit. Discussion with haematologists raised the possibility of C. canimorsus. Knowing the organism is slow growing on standard agar but visible as phagocytised rods in neutrophils and macrophages, the haematologist reviewed the peripheral blood film, which confirmed this suspicion. Microbiology colleagues isolated and identified the organism. Fortuitously, she was on appropriate antibiotics from the outset, but had presented late to the ED. Despite improved physiological parameters, she developed widespread necrosis requiring bilateral above knee amputations. After a turbulent period on ITU, including cardiac arrests, she rehabilitated well and made good physical and cognitive recovery; however, she has rehomed the dog. Discussion C. canimorsus is a fastidious, capnophilic gram negative rod, described in 1976 [1]. While previously known to cause sepsis and endocarditis in humans, the overwhelming majority of patients were immunosuppressed, including asplenic and alcoholic patients. A quarter of UK households own a dog [2]. There are over 7000 dog bites per year in the UK and PCR samples show presence of C. canimorsus in up to 75% of dogs and 57% of cats [3]. Thus, exposure to C. canimorsus is potentially grossly underestimated. Although tetanus is commonly thought of in the context of dog bites, C. canimorsus should not be overlooked. Patients should be advised to have low thresholds seeking medical advice regardless of tetanus status. C. canimorsus should always be considered in the differential diagnosis of any septic patient with a recent animal bite.
  • A multicentre prospective cohort study of the accuracy of conventional landmark technique for cricoid localisation using ultrasound scanning.

    Lee, David; Elriedy, Mohamed; Nair, Ashok (2018-07)
    Cricoid pressure is employed during rapid sequence induction to reduce the risk of pulmonary aspiration. Correct application of cricoid pressure depends on knowledge of neck anatomy and precise identification of surface landmarks. Inaccurate localisation of the cricoid cartilage during rapid sequence induction risks incomplete oesophageal occlusion, with potential for pulmonary aspiration of gastric contents. It may also compromise the laryngeal view for the anaesthetist. Accurate localisation of the cricoid cartilage therefore has relevance for the safe conduct of rapid sequence induction. We conducted a multicentre, prospective cohort study to determine the accuracy of cricoid cartilage identification in 100 patients. The cranio-caudal midpoint of the cricoid cartilage was identified by a qualified anaesthetic assistant using the conventional landmark technique and marked. While maintaining the patient in the same position, a second mark was made by identifying the midpoint of the cricoid cartilage using ultrasound scanning. The mean (SD) distance between the two marks was 2.07 (8.49) mm. In 41% of patients the midpoint was incorrectly identified by a margin greater than 5 mm. This error was uniformly distributed both above and below the midpoint of the cricoid cartilage. The Pearson correlation coefficient of this error with respect to body mass index was 0.062 (p = 0.539) and with age was -0.020 (p = 0.843). There were also no significant differences in error between male and female patients. Identification of cricoid position using a landmark technique has a high degree of variability and has little correlation with age, sex or body mass index. These findings have significant implications for the safe application of cricoid pressure in the context of rapid sequence induction.
  • Acute presentation of a partially obstructing laryngeal tumour: adjuvant agents to gaseous induction of anaesthesia.

    Walters, Matt (2018-07)
    We present the case of a 53-year-old man who attended our emergency department with stridor. He had recently undergone investigation for possible glottis cancer. We discuss the airway management of such a case. We believe this to be the first description of propofol target controlled infusion and clonidine to supplement a sevoflurane gas induction, in order to obtund response to intubation while maintaining spontaneous ventilation. We also consider how airway interventions may impact prognosis and need to be considered.
  • A randomised clinical trial comparing the 'sniffing' and neutral position using channelled (KingVision® ) and non-channelled (C-MAC® ) videolaryngoscopes

    Ungureanu, Narcis (2018-04)
    Head and neck position is one of the factors which can be associated with difficult videolaryngoscopy and tracheal intubation. This prospective randomised clinical trial compared 'sniffing' and neutral positions using a channelled (KingVision® ) and a non-channelled (C-MAC® D-blade) videolaryngoscope in 200 adult patients randomly allocated into four groups (KingVision 'sniffing', KingVision neutral, C-MAC 'sniffing' and C-MAC neutral). The primary outcome was the ease of tracheal intubation using the modified intubation difficulty scale (mIDS) score. Laryngoscopy time, intubation time, laryngoscopic view using the percentage of glottic opening (POGO) score and success rate of tracheal intubation were secondary outcomes. The median (IQR [range]) modified difficulty scale scores for the four groups, respectively, were 0 (0-1 [0-3]), 0 (0-1 [0-4]), 1 (0-1 [0-5]) and 0 (0-1 [0-3]; p = 0.384). There was no significant difference in laryngoscopy time (p = 0.020), intubation time (p = 0.272) and success rate (p = 0.968) between the groups. The percentage of glottic opening score was lower for C-MAC neutral group as compared with other three groups (p = 0.01). There was no significant difference in the ease of intubation between the 'sniffing' and the neutral position when using the KingVision and the C-MAC videolaryngoscopes. Therefore, either of the two positions could be used with these types of videolaryngoscopes, if deemed advantageous for the patient.
  • Femoral Nerve Block Intervention in Neck of Femur Fracture (FINOF): a randomised controlled trial.

    Walt, Gerrie Van De (2018-04)
    OBJECTIVE: Fractured neck of femur is a severely painful condition with significant mortality and morbidity. We investigated whether early and continuous use of femoral nerve block can improve pain on movement and mobility after surgery in older participants with fragility neck of femur fracture. DESIGN: Prospective single-centre, randomised controlled pragmatic trial. SETTING: Secondary care, acute National Health Service Trust, UK. PARTICIPANTS: Participants admitted with a history and examination suggesting fractured neck of femur. INTERVENTION: Immediate continuous femoral nerve block via catheter or standard analgesia. OUTCOME MEASURES: Primary outcome measures were Cumulative Dynamic Pain score and Cumulated Ambulation Score from surgery until day 3 postoperatively. Secondary outcome measures included pain scores at rest, cumulative side effects (nausea and constipation), quality of life (measured by EuroQOL 5 D instrument (EQ-5D) score) at day 3 and day 30, and rehabilitation outcome (measured by mobility score). RESULTS: 141 participants were recruited, with 23 excluded. No significant difference was detected between Cumulative Dynamic Pain Score (standard care (n=56) vs intervention (n=55) 20 (IQR 15-24) vs 20 (15-23), p=0.51) or Cumulated Ambulation Score (standard care vs intervention 6 (5-9) vs 7 (5-10), p=0.76). There were no statistically different differences in secondary outcomes except cumulative pain at rest: 5 (0.5-6.5) in the standard care group and 2 (0-5) in the intervention group (p=0.043). CONCLUSIONS: Early application of continuous femoral nerve block compared with standard systemic analgesia did not result in improved dynamic pain score or superior postoperative ambulation. This technique may provide superior pain relief at rest. Continuous femoral nerve block did not delay initial control of pain or mobilisation after surgery. TRIAL REGISTRATION NUMBER: ISRCTN92946117; Pre-results
  • Ultrasound guided popliteal sciatic block combined with femoral nerve block for managing a high risk patient on apixaban for i&d of footabscess

    Gnanamuttu, Anush; Haldar, Manabendra (2017)
    Current guidance is to avoid peripheral nerve blocks in the presence of anticoagulation. However in certain situations, where the risks of alternative techniques are high, then it may be appropriate to perform these blocks in the presence of anticoagulation. Here we present our management of a high risk anticoagulated patient who presented for incision and drainage of abscess using peripheral nerve blocks alone. Methods:We were asked to pre-assess a 89 year old patient posted for i&d of an absess of the foot. He had been admitted to hospital following falls and increased confusion and known to have COPD, hypertension, atrial fibrillation for which hewas on apixaban and congestive cardiac failure. His exercise tolerance was only 10 yards and saturations were 87% on air. Results: Ultrasound guided popliteal sciatic nerve and saphenous nerve block at the level of knee was performed. After 25 minutes there was almost complete motor block and surgery performedwithout any complications. Therewere no complications to report. Conclusions: Peripheral nerve blocks in the presence of anticoagulation can be associated with complications.Most of these have been associated with deep blocks or with peripheral nerve catheters. If the risks for alternative techniques are high, then on a relative risk basis, there may be role for peripheral nerve blocks in the presence of anticoagulation. The use of ultrasound guidance, helps avoid injury to vascular structures, which might cause nerve injury through haematoma formation.
  • Designing and delivering non-technical skills simulation based education in regional anaesthesia

    Bhatti, Tajammal (2017)
    In the last decade there has been rising interest in non-technical skills (NTS) in anaesthetic practice. These set of skills are important to maintain the efficiency of a working team and deliver high quality service. Despite the importance of the NTS, its role has not been adequately emphasised in regional anaesthesia teaching curricula. In an attempt to introduce the anaesthetic trainee to NTS in regional anaesthesia, we designed a simulation based teaching session, using both actor and high fidelity mannequin simulation. Methods: The designed simulation consisted of 4 stations. They incorporated task management, teamworking, situation awareness and decision making to assess anaesthetists' NTS. Two involved an actor, which included consenting an anxious patient for regional block and interviewing a patient with suspected nerve injury. The mannequin based simulation involved preparation, communication and ergonomics while performing regional anaesthesia, followed by critical incident. Each session was led by a trainee and feedback on performance given afterwards. Results: Through formal survey, the trainees highly valued the teaching session and the use of different styles of simulation. They felt it touched on important aspect of their daily practice which is rarely covered in formal teaching. Conclusions: We believe there is a room for improvement. For example introducing remote video recording for better reflective learning and more stations to enrich the educational experience.
  • Audit of airway assessment and documentation for emergency patients at the Royal Derby Hospital

    Thirugnanam, Madan; Edmondson, E (2016-06)
    Various methods of airway assessment exist in order to enable prediction of the difficult airway, be it difficult direct laryngoscopy, difficult intubation or difficult mask ventilation [1]. It is recognised that one method of assessment is insufficient to predict a difficult airway and a combination of tests should be used [2, 3]. This audit reviewed documentation of airway assessment for patients undergoing emergency surgery at the Royal Derby Hospital (RDH). This is typically a list with a high turnover of patients and anaesthetists, of varying experience, warranting high standards of documentation. Methods We retrospectively reviewed 50 anaesthesia charts of patients undergoing emergency surgical procedures from 12-29 January 2015. Audit standards were derived from a seminal paper by Calder [1]. Criteria we included were: interdental distance, dental health, mandibular protrusion, neck movement, thyromental distance and Mallampati classification. The first three criteria were described as a minimum to constitute an appropriate airway assessment by Calder, but we accepted any three as the minimum standard. We also recorded which anaesthetist pre-operatively assessed the patient and whether the same practitioner went on to induce anaesthesia. Results Of the 50 anaesthesia charts, 25 documented interdental distance; two documented jaw protrusion and 37 documented dental health. Three charts documented all three nominated criteria. In total, 15 charts documented a minimum of three assessments of the six we were examining. As described in Table 1, eight charts showed no evidence of an airway assessment, and of these eight charts, five were completed by consultant anaesthetists, one by a specialist trainee and one by a core trainee. The assessor of the eighth chart was undetermined. Twenty six patients were assessed and anaesthetised by the same person. Discussion These data show that documentation of airway assessment at RDH is poor, with 50% of charts failing to demonstrate at least three assessments of the airway. The review by Calder describes how it would be indefensible to induce anaesthesia only to then discover the patient has an interdental distance of 2 cm, rendering insertion of a supraglottic airway rescue device extremely difficult. Following this audit we can make the following recommendations: (Table Presented) .

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