Design and validation of a virtual reality trainer for ultrasound-guided regional anaesthesia

Virtual reality is a form of high-fidelity simulation that may be used to enhance the quality of medical education. We created a bespoke virtual reality trainer software using high resolution motion capture and ultrasound imagery to teach cognitive-motor needling skills necessary for the performance of ultrasound-guided regional anaesthesia. The primary objective of this study was to determine the construct validity between novice and experienced regional anaesthetists. Secondary objectives were: to create learning curves for needling performance; compare the virtual environment immersion with other high-fidelity virtual reality software; and compare cognitive task loads imposed by the virtual trainer compared with real-life medical procedures. We recruited 21 novice and 15 experienced participants, each of whom performed 40 needling attempts on four different virtual nerve targets. Performance scores for each attempt were calculated based on measured metrics (needle angulation, withdrawals, time taken) and compared between the groups. The degree of virtual reality immersion was measured using the Presence Questionnaire, and cognitive burden was measured using the NASA-Task Load Index. Scores by experienced participants were significantly higher than novices (p = 0.002) and for each nerve target (84% vs. 77%, p = 0.002; 86% vs. 79%, p = 0.003; 87% vs. 81%, p = 0.002; 87% vs. 80%, p = 0.003). Log–log transformed learning curves demonstrated individual variability in performance over time. The virtual reality trainer was rated as being comparably immersive to other high-fidelity virtual reality software in the realism, possibility to act and quality of interface subscales (all p > 0.06) but not in the possibility to examine and self-performance subscales (all p < 0.009). The virtual reality trainer created workloads similar to those reported in real-life procedural medicine (p = 0.53). This study achieved initial validation of our new virtual reality trainer and allows progression to a planned definitive trial that will compare the effectiveness of virtual reality training on real-life regional anaesthesia performance.     

Spinal or general anaesthesia for surgical repair of hip fracture and subsequent risk of mortality and morbidity: a database analysis using propensity score-matching

Around 76,000 people fracture their hip annually in the UK at a considerable personal, social and financial cost. Despite longstanding debate, the optimal mode of anaesthesia (general or spinal) remains unclear. Our aim was to assess whether there is a significant difference in mortality and morbidity between patients undergoing spinal anaesthesia compared with general anaesthesia during hip fracture surgery. A secondary analysis examined whether a difference exists in mortality for patients with pre-existing cardiovascular disease or chronic obstructive pulmonary disease. This was a clinical database analysis of patients treated for hip fracture in Nottingham, UK between 2004 and 2015. Propensity score-matching was used to generate matched pairs of patients, one of whom underwent each mode of anaesthesia. Data were analysed using conditional logistic regression, with 7164 patients successfully matched. There was no difference in 30- or 90-day mortality in patients who had spinal rather than general anaesthesia (OR [95%CI] 0.97 [0.8–1.15]; p = 0.764 and 0.93 [0.82–1.05]; p = 0.247 respectively). Patients who had a spinal anaesthetic had a lower-risk of blood transfusion (OR [95%CI] 0.84 [0.75–0.94]; p = 0.003) and urinary tract infection (OR [95%CI] 0.72 [0.61–0.84]; p < 0.001), but were more likely to develop a chest infection (OR [95%CI] 1.23 [1.07–1.42]; p = 0.004), deep vein thrombosis (OR [95%CI] 2.18 [1.07–4.45]; p = 0.032) or pulmonary embolism (OR [95%CI] 2.23 [1.16–4.29]; p = 0.016). The mode of anaesthesia for hip fracture surgery resulted in no significant difference in mortality, but there was a significant difference in several measures of postoperative morbidity.     

A randomised controlled trial of intravenous dexmedetomidine added to dexamethasone for arthroscopic rotator cuff repair and duration of interscalene block

Prolongation of peripheral nerve blockade by intravenous dexamethasone may be extended by intravenous dexmedetomidine. We randomly allocated 122 participants who had intravenous dexamethasone 0.15 mg.kg⁻¹ before interscalene brachial plexus block for day-case arthroscopic rotator cuff repair to intravenous saline (62 participants) or intravenous dexmedetomidine 1 μg.kg⁻¹ (60 participants). The primary outcome was time from block to first oral morphine intake during the first 48 postoperative hours. Fifty-nine participants reported taking oral morphine, 25/62 after placebo and 34/60 after dexmedetomidine, p = 0.10. The time to morphine intake was shorter after dexmedetomidine, hazard ratio (95%CI) 1.68 (1.00–2.82), p = 0.049. Median (IQR [range]) morphine doses were 0 (0–12.5 [0–50]) mg after control vs. 10 (0–30 [0–50]) after dexmedetomidine, a difference (95%CI) of 7 (0–10) mg, p = 0.056. There was no effect of dexmedetomidine on pain at rest or on movement. Intra-operative hypotension was recorded for 27/62 and 50/60 participants after placebo vs. dexmedetomidine, respectively, p < 0.001. Other outcomes were similar, including durations of sensory and motor block. In conclusion, dexmedetomidine shortened the time to oral morphine consumption after interscalene block combined with dexamethasone and caused intra-operative hypotension.     

A randomised trial of bilateral erector spinae plane block vs. no block for thoracolumbar decompressive spinal surgery

Major spinal surgery causes significant postoperative pain. We tested the efficacy and safety of bilateral erector spinae block on quality of recovery and pain after thoracolumbar decompression. We randomly allocated 60 adults to standard care or erector spinae block. Erector spinae block improved the mean (SD) quality of recovery-15 score at 24 postoperative hours, from 119 (20) to 132 (14), an increase (95%CI) of 13 (4–22), p = 0.0044. Median (IQR [range]) comprehensive complication index was 1 (0–3 [0–5]) in the control group vs. 1 (0–1 [0–4]) after block, p = 0.4. Erector spinae block reduced mean (SD) area under the curve pain during the first 24 postoperative hours: at rest, from 78 (49) to 50 (39), p = 0.018; and on sitting, from 125 (51) to 91 (50), p = 0.009. The cumulative mean (SD) oxycodone consumption to 24 h was 27 (18) mg in the control group and 19 (26) mg after block, p = 0.20. In conclusion, erector spinae block improved recovery and reduced pain for 24 h after thoracolumbar decompression surgery.     

A survey of antenatal and peripartum provision of information on analgesia and anaesthesia

Pregnant women should receive information about what they might expect to experience during their delivery. Despite this, research shows many women are inadequately prepared for anaesthetic interventions during labour. We surveyed 903 postnatal women across 28 Greater London hospitals about: the analgesic and anaesthetic information that they recalled receiving during pregnancy and delivery; their confidence to make decisions on analgesia; and their satisfaction with the analgesia used. Wide variation was observed between hospitals. Overall, 67 of 749 (9.0%) women recalled receiving antenatal information covering all aspects of labour analgesia, and 108 of 889 (12.1%) covering anaesthesia for caesarean section. Regarding intrapartum information, 256 of 415 (61.7%) respondents recalled receiving thorough information before epidural insertion for labour analgesia, and 102 of 370 (27.6%) before anaesthesia for caesarean section. We found that 620 of 903 (68.7%) women felt well enough informed to be confident in their analgesic choices, and 675 of 903 (74.8%) stated that their analgesia was as expected or better. Receiving information verbally, regardless of provider, was the factor most strongly associated with respondents recalling receiving full information: odds ratio (95%CI) for labour analgesia 20.66 (8.98–47.53; p < 0.0001); epidural top-up for caesarean section 5.93 (1.57–22.35; p = 0.01); and general anaesthesia for caesarean section 12.39 (2.18–70.42; p = 0.01). A large proportion of respondents did not recall being fully informed before an anaesthetic intervention. Collaboration with current antenatal service providers, both in promoting information delivery and providing resources to assist with delivery, could improve the quality of information offered and women's retention of that information.     

Age‐disparate sex and HIV risk for young women from 2002 to 2012 in South Africa

Introduction : Age‐disparate sex has long been considered a factor that increases HIV risk for young women in South Africa. However, recent studies from specific regions in South Africa have found conflicting evidence. Few studies have assessed the association between age‐disparate partnerships (those involving an age gap of 5 years or more) and HIV risk at the national level. This study investigates the relationship between age‐disparate sex and HIV status among young women aged 15–24 in South Africa. Methods : Nationally representative weighted data from the 2002, 2005, 2008, and 2012 South African National HIV Surveys were analysed for young women aged 15–24 years using bivariate analyses and multiple logistic regressions. Results : After conducting multiple logistic regression analyses and controlling for confounders, young women with age‐disparate partners had greater odds of being HIV positive in every survey year: 2002 (aOR = 1.74, 95%CI: 0.81–3.76, p = 0.16); 2005 (aOR = 2.11, 95%CI: 1.22–3.66, p < 0.01); 2008 (aOR = 2.02, 95%CI: 1.24–3.29, p < 0.01); 2012 (aOR = 1.53, 95%CI: 0.92–2.54, p < 0.1). The odds of being HIV positive increased for each year increase in their male partner’s age in 2002 (aOR = 1.10, 95%CI: 0.98–1.22, p = 0.11), 2005 (aOR = 1.10, 95%CI: 1.03–1.17, p < 0.01), 2008 (aOR = 1.08, 95%CI: 1.01–1.15, p < 0.05), and 2012 (aOR = 1.08, 95%CI: 1.01–1.16, p < 0.05). Findings were statistically significant (p < 0.1) for the years 2005, 2008, and 2012. Conclusions : Our findings suggest that age‐disparate sex continues to be a risk factor for young women aged 15–24 in South Africa at a national level. These results may reflect variation in HIV risk at the national level compared to the differing results from recent studies in a demographic surveillance system and trial contexts. In light of recent contradictory study results, further research is required on the relationship between age‐disparate sex and HIV for a more nuanced understanding of young women’s HIV risk.     

Decision-to-delivery interval and neonatal outcomes for category-1 caesarean sections during the COVID-19 pandemic

General anaesthesia is known to achieve the shortest decision-to-delivery interval for category-1 caesarean section. We investigated whether the COVID-19 pandemic affected the decision-to delivery interval and influenced neonatal outcomes in patients who underwent category-1 caesarean section. Records of 562 patients who underwent emergency caesarean section between 1 April 2019 and 1 July 2019 in seven UK hospitals (pre-COVID-19 group) were compared with 577 emergency caesarean sections performed during the same period during the COVID-19 pandemic (1 April 2020–1 July 2020) (post-COVID-19 group). Primary outcome measures were: decision-to-delivery interval; number of caesarean sections achieving decision-to-delivery interval < 30 min; and a composite of adverse neonatal outcomes (Apgar 5-min score < 7, umbilical arterial pH < 7.10, neonatal intensive care unit admission and stillbirth). The use of general anaesthesia decreased significantly between the pre- and post-COVID-19 groups (risk ratio 0.48 (95%CI 0.37–0.62); p < 0.0001). Compared with the pre-COVID-19 group, the post-COVID-19 group had an increase in median (IQR [range]) decision-to-delivery interval (26 (18–32 [4–124]) min vs. 27 (20–33 [3–102]) min; p = 0.043) and a decrease in the number of caesarean sections meeting the decision-to-delivery interval target of < 30 min (374/562 (66.5%) vs. 349/577 (60.5%); p = 0.02). The incidence of adverse neonatal outcomes was similar in the pre- and post-COVID-19 groups (140/568 (24.6%) vs. 140/583 (24.0%), respectively; p = 0.85). The small increase in decision-to-delivery interval observed during the COVID-19 pandemic did not adversely affect neonatal outcomes.     

High-flow nasal oxygen vs. standard flow-rate facemask pre-oxygenation in pregnant patients: a randomised physiological study

High-flow nasal oxygen has been shown to provide effective pre-oxygenation and prolong apnoeic time during intubation attempts in non-pregnant patients. We aimed to compare pre-oxygenation using high-flow nasal oxygen (30–70 l.min⁻¹ oxygen flow) via nasal prongs with standard 15 l.min⁻¹ oxygen breathing via a tight-fitting facemask. Forty healthy parturients were randomly allocated to these two groups, and furthermore each patient underwent the selected pre-oxygenation method with both 3-min tidal volume breathing and 30s tidal breathing followed by eight vital capacity breaths. With 3-min tidal volume breathing, the respective estimated marginal means for high-flow nasal oxygen and standard flow rate facemask pre-oxygenation were 87.4% (95%CI 85.5–89.2%) and 91.0% (95%CI 89.3–92.7%), p = 0.02; with eight vital capacity breaths the estimated marginal means were 85.9% (95%CI 84.1–87.7%) and 91.8% (95%CI 90.1–93.4%, p < 0.0001). Furthermore, high-flow nasal oxygen did not reliably achieve a mean end-tidal oxygen concentration ≥ 90% compared with the standard flow rate facemask. In this physiological study, high-flow nasal oxygen pre-oxygenation performed worse than standard flow rate facemask pre-oxygenation in healthy term parturients.     

Incidence of severe critical events in paediatric anaesthesia in the United Kingdom: secondary analysis of the anaesthesia practice in children observational trial (APRICOT study)

The anaesthesia practice in children observational trial of 31,127 patients in 261 European hospitals revealed a high (5.2%) incidence of severe critical events in the peri-operative period and wide variability in practice. A sub-analysis of the UK data was undertaken to investigate differences compared with the non-UK cohort in the incidence and nature of peri-operative severe critical events and to attempt to identify areas for quality improvement. In the UK cohort of 7040 paediatric patients from 43 hospitals, the overall incidence of peri-operative severe critical events was lower than in the non-UK cohort (3.3%, 95%CI: 2.9–3.8 vs. 5.8%, 95%CI: 5.5–6.1, RR 0.57, p < 0.001). There was a lower rate of bronchospasm (RR 0.22, 95%CI: 0.14–0.33; p < 0.001), stridor (RR 0.42, 95%CI: 0.28–0.65; p < 0.001) and cardiovascular instability (RR 0.69, 95%CI: 0.55–0.86; p = 0.001) than in the non-UK cohort. The proportion of sicker patients where less experienced teams were managing care was lower in the UK than in the non-UK cohort (10.4% vs. 20.4% of the ASA physical status 3 and 9% vs. 12.9% of the ASA physical status 4 patients). Differences in work-load between centres did not affect the incidence and outcomes of severe critical events when stratified for age and ASA physical status. The lower incidence of cardiovascular and respiratory complications could be partly attributed to more experienced dedicated paediatric anaesthesia providers managing the higher risk patients in the UK. Areas for quality improvement include: standardisation of serious critical event definitions; increased reporting; development of evidence-based protocols for management of serious critical events; development and rational use of paediatric peri-operative risk assessment scores; implementation of current best practice in provision of competent paediatric anaesthesia services in Europe; development of specific training in the management of severe peri-operative critical events; and implementation of systems for ensuring maintenance of skills.     

Incidence of accidental awareness during general anaesthesia in obstetrics: a multicentre,prospective cohort study

General anaesthesia for obstetric surgery has distinct characteristics that may contribute towards a higher risk of accidental awareness during general anaesthesia. The primary aim of this study was to investigate the incidence, experience and psychological implications of unintended conscious awareness during general anaesthesia in obstetric patients. From May 2017 to August 2018, 3115 consenting patients receiving general anaesthesia for obstetric surgery in 72 hospitals in England were recruited to the study. Patients received three repetitions of standardised questioning over 30 days, with responses indicating memories during general anaesthesia that were verified using interviews and record interrogation. A total of 12 patients had certain/probable or possible awareness, an incidence of 1 in 256 (95%CI 149–500) for all obstetric surgery. The incidence was 1 in 212 (95%CI 122–417) for caesarean section surgery. Distressing experiences were reported by seven (58.3%) patients, paralysis by five (41.7%) and paralysis with pain by two (16.7%). Accidental awareness occurred during induction and emergence in nine (75%) of the patients who reported awareness. Factors associated with accidental awareness during general anaesthesia were: high BMI (25–30 kg.m^-2); low BMI (<18.5 kg.m^-2); out-of-hours surgery; and use of ketamine or thiopental for induction. Standardised psychological impact scores at 30 days were significantly higher in awareness patients (median (IQR [range]) 15 (2.7–52.0 [2–56]) than in patients without awareness 3 (1–9 [0–64]), p = 0.010. Four patients had a provisional diagnosis of post-traumatic stress disorder. We conclude that direct postoperative questioning reveals high rates of accidental awareness during general anaesthesia for obstetric surgery, which has implications for anaesthetic practice, consent and follow-up.     

The association between labour epidural case volume and the rate of accidental dural puncture

Accidental dural puncture is a recognised complication of labour epidural placement and can cause a debilitating headache. We examined the association between labour epidural case volume and accidental dural puncture rate in specialist anaesthetists and anaesthesia trainees. We performed a retrospective cohort study of labour epidural and combined spinal-epidural nerve blocks performed between 1 July 2013 and 31 December 2017 at Waitemata District Health Board, Auckland, New Zealand. The mean (SD) annual number of obstetric epidural and combined spinal-epidural procedures for high-case volume specialists was 44.2 (15.0), and for low-case volume specialists was 10.0 (6.8), after accounting for caesarean section combined spinal-epidural procedures. Analysis of 7976 labour epidural and combined spinal-epidural procedure records revealed a total of 92 accidental dural punctures (1.2%). The accidental dural puncture rate (95%CI) in high-case volume specialists was 0.6% (0.4–0.9%) and in low-case volume specialists 2.4% (1.4–3.9%), indicating probable skill decay. The odds of accidental dural puncture were 3.77 times higher for low- compared with high-case volume specialists (95%CI 1.72–8.28, p = 0.001). Amongst trainees, novices had a significantly higher accidental dural puncture complication rate (3.1%) compared with registrars (1.2%), OR (95%CI) 0.39 (0.18–0.84), p = 0.016, or fellows (1.1%), 0.35 (0.16–0.76), p = 0.008. Accidental dural puncture complication rates decreased once trainees progressed past the ‘novice’ training stage.     

Techniques,anaesthesia preferences,and outcomes of Achilles tenotomy during Ponseti method of idiopathic clubfoot correction: A systematic review

BackgroundAchilles tenotomy (AT) forms an important aspect of Ponseti’s casting method and is performed in 80–90% of idiopathic clubfoot cases to correct residual hindfoot equinus. Different techniques are described in the literature with no clarity on which method is superior. This review aims to analyse the various techniques described, anaesthesia preferences, and outcomes of AT.MethodsWe searched PubMed, Embase, Scopus, and Ovid MEDLINE for articles describing idiopathic clubfoot cases undergoing primary AT during Ponseti’s casting method. Data were extracted from eligible studies for qualitative and quantitative synthesis. The repeat tenotomy and complication rates were taken as outcome parameters.ResultsNineteen studies were included for systematic review. A percutaneous AT using a scalpel or needle is adequate in most cases and shows promising results. The out-patient department (OPD) tenotomies under local anaesthesia (LA) and operation room (OR) tenotomies under general anaesthesia (GA) were associated with a repeat tenotomy (RT) rate of 2.5% (95%CI, 0.4−5.4%) and 0.8% (95%CI, 0–1.6%), respectively. The difference between OPD and OR groups was not statistically significant (p = 0.875). The pooled analysis shows a failure/relapse rate of 4.2% (1.9–6.4%, p < 0.001) after AT. OPD and OR tenotomies were associated with a complication rate of 1.6% (95%CI, 0.2–3.0%) and 0.5% (95%CI, 0.1–0.8%), respectively, and the difference was not statistically significant (p = 0.807). Bleeding is the most common complication and is controlled in most cases by applying local pressure.ConclusionPerforming Achilles tenotomy in OPD under LA is safe and cost-effective with similar success rates to those done under GA. With the lack of many comparative and higher-level evidence studies at present, we can’t conclude if one technique is better than another.     

The association of pre-operative anaemia with morbidity and mortality after emergency laparotomy

Pre-operative anaemia is associated with poor outcomes after elective surgery but its relationship with outcomes after emergency surgery is unclear. We analysed National Emergency Laparotomy Audit data from 1 December 2013 to 30 November 2017, excluding laparotomy for haemorrhage. Anaemia was classified as ‘mild’ 129–110 g.l−1; ‘moderate’ 109–80 g.l−1; or ‘severe’ ≤ 79 g.l−1. The primary outcome was 90-day mortality. Secondary outcomes were 30-day mortality, return to theatre and postoperative hospital stay. The primary outcome was available for 86,763 patients, of whom 45,306 (52%) were anaemic. There were 12,667 (15%) deaths at 90 postoperative days and 9246 (11%) deaths at 30 postoperative days. Anaemia was associated with increased 90-day and 30-day mortality, odds ratio (95%CI): mild, 1.15 (1.09–1.21); moderate, 1.44 (1.36–1.52); and severe, 1.42 (1.24–1.63), p < 0.001 for all; mild, 1.07 (1.00–1.12), p = 0.030; moderate, 1.30 (1.21–1.38), p < 0.001; and severe, 1.22 (1.05–1.43), p = 0.010, respectively. All categories of anaemia were associated with prolonged hospital stay, adjusted coefficient (95%CI): mild, 1.31 (1.01–1.62); moderate, 3.41 (3.04–3.77); severe, 2.80 (1.83–3.77), p < 0.001 for all. Moderate and severe anaemia were associated with increased risk of return to the operating theatre, odds ratio (95%CI): moderate 1.13 (1.06–1.21), p < 0.001; and severe 1.23 (1.06–1.43), p = 0.006. Pre-operative anaemia is common in patients undergoing emergency laparotomy and is associated with increased postoperative mortality and morbidity.     

The effect of an ultrasound-activated needle tip tracker needle on the performance of sciatic nerve block on a soft embalmed Thiel cadaver

In this study, we measured the performance of medical students and anaesthetists using a new tracker needle during simulated sciatic nerve block on soft embalmed cadavers. The tracker needle incorporates a piezo element near its tip that generates an electrical signal in response to insonation. A circle, superimposed on the ultrasound image surrounding the needle tip, changes size and colour according to the position of the piezo element within the ultrasound beam. Our primary objective was to compare sciatic block performance with the tracker switched on and off. Our secondary objectives were to record psychometrics, procedure efficiency, participant self-regulation and focused attention using eye-tracking technology. Our primary outcome measures were the number of steps successfully performed and the number of errors committed during each block. Videos were scored by trained experts using validated checklists. Sequential tracker activation and deactivation was randomised equally within subjects. With needle activation, steps improved in 10 (25%) subjects and errors reduced in six (15%) subjects. The most important steps were: needle tip identification before injection, OR (95%CI) 2.12 (1.61–2.80; p < 0.001); and needle tip identification before advance of the needle, 1.80 (1.36–2.39; p < 0.001). The most important errors were: failure to identify the needle tip before injection, 2.40 (1.78–3.24; p < 0.001); and failure to quickly regain needle tip position when tip visibility was lost, 2.03 (1.5–2.75; p < 0.001). In conclusion, needle-tracking technology improved performance in a quarter of subjects.     

A randomised controlled trial of pectoral nerve-2 (PECS 2) block vs. serratus plane block for chronic pain after mastectomy

Thoracic interfascial plane blocks are effective for post-mastectomy acute analgesia. However, their effects on chronic pain are uncertain. We randomly allocated 80 women equally to pectoral nerve-2 (PECS 2) block or serratus plane block. The pectoral nerve-2 block reduced the rate of moderate or severe chronic pain from 13/40 (33%) with the serratus plane block to 4/40 (10%), p = 0.03, adjusted odds ratio (95%CI) 0.23 (0.07–0.80), p = 0.02. The rates of pain-free women at six postoperative months were indeterminate, 10/40 (25%) after serratus plane block vs. 19/40 (48%) after pectoral nerve-2 block, p = 0.06, adjusted odds ratio (95%CI) 2.9 (1.1–7.5), p = 0.03. Health-related quality of life at six postoperative months was similar after serratus plane and pectoral nerve-2 blocks, mean (SD) EQ-5D-3L scores 0.87 (0.15) vs. 0.91 (0.14), respectively, p = 0.21. The pectoral nerve-2 block reduced median (IQR [range]) morphine consumption in the first 24 postoperative hours from 6 (3–9 [1–25]) mg to 4 (2–7 [0–37]) mg, p = 0.04. However, acute pain scores after serratus plane and pectoral nerve-2 blocks were similar, median (IQR [range]) 23 (11–35 [0–70]) mm vs. 18 (11–27 [0–61]) mm, respectively, p = 0.44. Pectoral nerve-2 block reduced chronic pain 6 months after mastectomy compared with serratus plane block.     

Operating room‐to‐incision interval and neonatal outcome in emergency caesarean section: a retrospective 5‐year cohort study

We conducted a 5‐year retrospective cohort study on women undergoing caesarean section to investigate factors influencing the operating room‐to‐incision interval. Time‐to‐event analysis was performed for category‐1 caesarean section using a Cox proportional hazards regression model. Covariates included: anaesthetic technique; body mass index; age; parity; time of delivery; and gestational age. Binary logistic regression was performed for 5‐min Apgar score ≥ 7. There were 677 women who underwent category‐1 caesarean section and who met the entry criteria. Unadjusted median (IQR [range]) operating room‐to‐incision intervals were: epidural top‐up 11 (7–17 [0–87]) min; general anaesthesia 6 (4–11 [0–69]) min; spinal 13 (10–20 [0–83]) min; and combined spinal‐epidural 24 (13–35 [0–75]) min. Cox regression showed general anaesthesia to be the most rapid method with a hazard ratio (95%CI) of 1.97 (1.60–2.44; p < 0.0001), followed by epidural top‐up (reference group), spinal anaesthesia 0.79 (0.65–0.96; p = 0.02) and combined spinal‐epidural 0.48 (0.35–0.67; p < 0.0001). Underweight and overweight body mass indexes were associated with longer operating room‐to‐incision intervals. General anaesthesia was associated with fewer 5‐min Apgar scores ≥ 7 with an odds ratio (95%CI) of 0.28 (0.11–0.68; p < 0.01). There was no difference in neonatal outcomes between the first and fifth quintiles for operating room‐to‐incision intervals. General anaesthesia is associated with the most rapid operating room‐to‐incision interval for category‐1 caesarean section, but is also associated with worse short term neonatal outcomes. Longer operating room‐to‐incision intervals were not associated with worse neonatal outcomes.     

Analgesic efficacy of PECS and serratus plane blocks after breast surgery: A systematic review,meta-analysis and trial sequential analysis

Study objectiveTo determine whether pectoral nerves (PECS) blocks provide effective postoperative analgesia when compared with no regional technique in patients undergoing breast surgery.DesignSystematic review, meta-analysis and trial sequential analysis.SettingOperating room, postoperative recovery area and ward, up to 24 postoperative hours.PatientsPatients undergoing breast surgery under general anaesthesia with either PECS block or no regional technique.InterventionsWe searched five electronic databases for randomized controlled trials comparing PECS block with no block or sham injection.MeasurementsThe primary outcome was rest pain scores (analogue scale, 0–10) at 2 h, analysed according to surgery (mastectomy vs other breast surgery) and regional technique (PECS 2 vs other blocks), among others. Secondary outcomes included morphine equivalent consumption, and rate of postoperative nausea and vomiting at 24 h.Main resultsSixteen trials including 1026 patients were identified. Rest pain scores at 2 h were decreased in the PECS blocks group, with a mean (95%CI) difference of −1.5 (−2.0, −1.0); I2 = 93%; p < 0.001, with no differences between surgery (mastectomy, mean difference [95%CI]: −1.8 [−2.4, −1.2], I² = 91%, p < 0.001; other breast surgery, mean difference [95%CI]: −1.1 [−2.1, −0.1], I² = 94%, p = 0.03; p for subgroup difference = 0.25), and regional technique (PECS 2, mean differences [95%CI]: −1.6 [−2.3, −1.0], I² = 94%, p < 0.001; other blocks, mean differences [95%CI]: −1.3 [−2.4, −0.1], I² = 74%, p = 0.04; p for subgroup difference = 0.57). The rate of postoperative nausea and vomiting was reduced from 30.8% (95%CI: 25.7%, 36.3%) to 18.7% (95%CI, 14.4%, 23.5%; p = 0.01). Similarly, secondary outcomes were significantly improved in the PECS blocks group. The overall quality of evidence was moderate-to-high.ConclusionsThere is moderate-to-high level evidence that PECS blocks provide postoperative analgesia after breast surgery when compared with no regional technique and reduce rate of PONV. This might provide the most benefit to those at high-risk of postoperative pain.     

The effect of anaesthetic technique during primary breast cancer surgery on neutrophil–lymphocyte ratio,platelet–lymphocyte ratio and return to intended oncological therapy

Inflammation and immunosuppression contribute to the pathogenesis of cancer. An increased neutrophil–lymphocyte ratio reflects these processes and is associated with adverse cancer outcomes. Whether anaesthetic technique for breast cancer surgery influences these factors, and potentially cancer recurrence, remains unknown. We conducted a secondary analysis in patients enrolled in an ongoing trial of anaesthetic technique on breast cancer recurrence. The primary hypothesis was that postoperative neutrophil–lymphocyte ratio is lower in patients allocated to receive propofol‐paravertebral rather than inhalational agent‐opioid anaesthesia for primary breast cancer surgery. Among 397 patients, 116 had differential white cell counts performed pre‐operatively and postoperatively. Pre‐operative neutrophil–lymphocyte ratio was similar in the propofol‐paravertebral 2.3 (95%CI 1.8–2.8) and inhalational agent‐opioid anaesthesia 2.2 (1.9–3.2) groups, p = 0.72. Postoperative neutrophil–lymphocyte ratio was lower (3.0 (2.4–4.2) vs. 4.0 (2.9–5.4), p = 0.001) in the propofol‐paravertebral group. Propofol‐paravertebral anaesthesia attenuated the postoperative increase in the neutrophil‐lymphocyte ratio.     

Effects of tracheal intubation and tracheal tube position on regional lung ventilation: an observational study

Anaesthesia and positive pressure ventilation cause ventral redistribution of regional ventilation, potentially caused by the tracheal tube. We used electrical impedance tomography to map regional ventilation during anaesthesia in 10 patients with and without a tracheal tube. We recorded impedance data in subjects who were awake, during bag-mask ventilation, with the tracheal tube positioned normally, rotated 90° to each side and advanced until in an endobronchial position. We recorded the following measurements: ventilation of the right lung (proportion, %); centre of ventilation (100% = entirely ventral); global inhomogeneity (0% = homogenous); and regional ventilation delay, an index of temporal heterogeneity. We compared the results using Student's t-tests. Relative to subjects who were awake, anaesthesia with bag-mask ventilation reduced right-sided ventilation by 5.6% (p = 0.002), reduced regional ventilation delay by 1.6% (p = 0.025), and moved the centre of ventilation ventrally from 51.4% to 58.2% (p = 0.0001). Tracheal tube ventilation caused a further centre of ventilation increase of 1.3% (p = 0.009). With the tube near the carina, right-sided ventilation increased by 3.2% (p = 0.031) and regional ventilation delay by 2.8% (p = 0.049). Tube rotation caused a 1.6% increase in right-sided ventilation compared with normal position (p = 0.043 left and p = 0.031 right). Global inhomogeneity remained mostly unchanged. Ventral ventilation with positive pressure ventilation occurred with bag-mask ventilation, but was exacerbated by a tracheal tube. Tube position influenced ventilation of the right and left lungs, while ventilation overall remained homogenous. Tube rotation in either direction resulted in ventilation patterns being closer to when awake than either bag-mask ventilation or a normally positioned tube. These results suggest that even ideal tube positioning cannot avoid the ventral shift in ventilation.