Pain management after laparoscopic cholecystectomy: A systematic review and procedure-specific postoperative pain management (PROSPECT) recommendations.

Laparoscopic cholecystectomy can be associated with significant postoperative pain that is difficult to treat. We aimed to evaluate the available literature and develop updated recommendations for optimal pain management after laparoscopic cholecystectomy. A systematic review was performed using the procedure-specific postoperative pain management (PROSPECT) methodology. Randomised controlled trials and systematic reviews published in the English language from August 2017 to December 2022 assessing postoperative pain after laparoscopic cholecystectomy using analgesic, anaesthetic or surgical interventions were identified from MEDLINE, Embase and Cochrane Databases. From 589 full text articles, 157 randomised controlled trials and 31 systematic reviews met the inclusion criteria. Paracetamol combined with NSAIDs or cyclo-oxygenase-2 inhibitors should be given either pre-operatively or intra-operatively, unless contraindicated. In addition, intra-operative intravenous (i.v.) dexamethasone, port-site wound infiltration or intraperitoneal local anaesthetic instillation are recommended, with opioids used for rescue analgesia. As a second-line regional technique, the erector spinae plane block or transversus abdominis plane block may be reserved for patients with a heightened risk of postoperative pain. Three-port laparoscopy, a low-pressure pneumoperitoneum, umbilical port extraction, active aspiration of the pneumoperitoneum and saline irrigation are recommended technical aspects of the operative procedure. The following interventions are not recommended due to limited or no evidence on improved pain scores: single port or mini-port techniques, routine drainage, low flow insufflation, natural orifice transluminal endoscopic surgery (NOTES), infra-umbilical incision, i.v. clonidine, nefopam and regional techniques such as quadratus lumborum block or rectus sheath block. Several interventions provided better pain scores but are not recommended due to risk of side effects: spinal or epidural anaesthesia, gabapentinoids, i.v. lidocaine, i.v. ketamine and i.v. dexmedetomidine.

The role of supraglottic airway devices for caesarean section under general anaesthesia. A scoping literature review with a proposed algorithm for the appropriate use of supraglottic airway devices for caesarean sections.

This review aims to assess the published evidence on airway management with a supraglottic airway device (SGA) for general anaesthesia in patients requiring a caesarean section. Physiological changes during pregnancy can make airway management in parturients challenging. At the same time, pregnant patients are at risk of pulmonary aspiration due to hormonal and mechanical alterations. The standard airway management for parturients undergoing caesarean section is rapid sequence induction followed by tracheal intubation. Evidence exists that using second-generation SGA devices is well tolerated and effective in selected patients. In this review, we provide an overview of the existing evidence and provide an algorithm to make an evidence-based clinical decision on the use of SGA devices. An online literature search was performed in Medline, Embase, PubMed, Emcare, Cochrane Library and CINAHL. The search terms used were 'supraglottic airway', 'supraglottic airway device', 'supraglottic airway management', 'supraglottic tube', 'i-gel', laryngeal mask', 'laryngeal mask airway', 'LMA', 'SGA', 'Proseal', 'Supreme', 'obstetric surgery', 'obstetric operation', 'general anaesthesia', 'caesarean' or 'caesarean section', 'abdominal delivery'. Full-text articles in English, Dutch and French were included. Case reports and studies in which the surgery was not a caesarean section were excluded. The initial search yielded 815 results. Following screening, deduplication and removal of publications that were unrelated to the topic or did not fit the inclusion criteria, 13 manuscripts were included in our analysis. A total of 7722 patients were described in the articles included. In the majority of manuscripts, second-generation SGA devices were used. There were seven cases of failed insertion and a need for conversion to tracheal intubation; first-generation SGA devices were used in these cases. There were no cases of pulmonary aspiration, and only one case of gastric regurgitation was described. Growing evidence suggests that the use of second-generation SGA devices might be well tolerated as the primary method for securing the airway for caesarean sections requiring general anaesthesia, in selected patients with a low risk for aspiration and difficult intubation.

Axillary Brachial Plexus Block Compared with Other Regional Anesthesia Techniques in Distal Upper Limb Surgery: A Systematic Review and Meta-Analysis.

Background: Several regional anesthesia (RA) techniques have been described for distal upper limb surgery. However, the best approach in terms of RA block success rate and safety is not well recognized. Objective: To assess and compare the surgical anesthesia and efficacy of axillary brachial plexus block with other RA techniques for hand and wrist surgery. The attainment of adequate surgical anesthesia 30 min after block placement was considered a primary outcome measure. Additionally, successful block outcomes were required without the use of supplemental local anesthetic injection, systemic opioid analgesia, or the need to convert to general anesthesia. Methods: We performed a systematic search in the following databases: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and CENTRAL. RCTs comparing axillary blocks with other brachial plexus block techniques, distal peripheral forearm nerve block, intravenous RA, and the wide-awake local anesthesia no tourniquet (WALANT) technique were included. Results: In total, 3070 records were reviewed, of which 28 met the inclusion criteria. The meta-analysis of adequate surgical anesthesia showed no significant difference between ultrasound-guided axillary block and supraclavicular block (RR: 0.94 [0.89, 1.00]; p = 0.06; I2 = 60.00%), but a statistically significant difference between ultrasound-guided axillary block and infraclavicular block (RR: 0.92 [0.88, 0.97]; p < 0.01; I2 = 53.00%). Ultrasound-guided infraclavicular blocks were performed faster than ultrasound-guided axillary blocks (SMD: 0.74 [0.30, 1.17]; p < 0.001; I2 = 85.00%). No differences in performance time between ultrasound-guided axillary and supraclavicular blocks were demonstrated. Additionally, adequate surgical anesthesia onset time was not significantly different between ultrasound-guided block approaches: ultrasound-guided axillary blocks versus ultrasound-guided supraclavicular blocks (SMD: 0.52 [-0.14, 1.17]; p = 0.12; I2 = 86.00%); ultrasound-guided axillary blocks versus ultrasound-guided infraclavicular blocks (SMD: 0.21 [-0.49, 0.91]; p = 0.55; I2 = 92.00%). Conclusions: The RA choice should be individualized depending on the patient, procedure, and operator-specific parameters. Compared to ultrasound-guided supraclavicular and infraclavicular block, ultrasound-guided axillary block may be preferred for patients with significant concerns of block-related side effects/complications. High heterogeneity between studies shows the need for more robust RCTs.

Pain management after open colorectal surgery: An update of the systematic review and procedure-specific postoperative pain management (PROSPECT) recommendations.

BACKGROUND: Open colectomy is still performed around the world and associated with significant postoperative pain. OBJECTIVES: Unpublished recommendations based on a systematic review were proposed by the PROcedure SPECific postoperative pain managemenT (PROSPECT) group in 2016. We aimed to update these recommendations by evaluating the available literature and develop recommendations for optimal pain management after open colectomy according to the PROSPECT methodology. DESIGN AND DATA SOURCES: A systematic review using the PROSPECT methodology was undertaken. Randomised controlled trials and systematic reviews published in the English language from 2016 to 2022 assessing postoperative pain after open colectomy using analgesic, anaesthetic or surgical interventions were identified. The primary outcome included postoperative pain scores. RESULTS: The previous 2016 review included data from 93 studies. Out of 842 additional eligible studies identified, 13 new studies were finally retrieved for analysis. Intra-operative and postoperative interventions that improved postoperative pain were paracetamol, epidural analgesia. When epidural is not feasible, intravenous lidocaine or bilateral TAP block or postoperative continuous pre-peritoneal infusion are recommended. Intra-operative and postoperative Cyclo-oxygenase (COX)-2 specific-inhibitors or non-steroidal anti-inflammatory drugs (NSAIDs) are recommended for colonic surgery. CONCLUSIONS: The analgesic regimen for open colectomy should include intra-operative paracetamol and COX-2 specific inhibitors or NSAIDs (restricted to colonic surgery), epidural and continued postoperatively with opioids used as rescue analgesics. If epidural is not feasible, bilateral TAP block or IV lidocaine are recommended. Safety issues should be highlighted: local anaesthetics should not be administered by two different routes at the same time. Because of the risk of toxicity, careful dosing and monitoring are necessary.

High dose glucocorticoids for treatment of postoperative pain: A systematic review of the literature and meta-analysis.

STUDY OBJECTIVE: Glucocorticoids as a component of multimodal analgesia have been studied for many years and their post-operative analgesic effects appear to be dose-dependent. We conducted a systematic review of randomized controlled trials (RCTs) to evaluate the evidence of peri-operative high dose corticosteroid therapy in comparison to placebo (placebo drug) or control group (no treatment) for improving the quality of post-operative analgesia as indicated by a reduction of 10 mm in 100 mm Visual Analogue Scale (VAS) or reduction of 1 point in a 0-10 point VAS scale, or a reduction of 1 point in an 11-point Numerical Rating Scale (NRS) score, or reduction of rescue opioid analgesia, in patients undergoing all types of surgery. DESIGN: Systematic review of RCTs with meta-analysis. SETTING: Acute postoperative pain treatment in non-obese adult population. INTERVENTIONS: Perioperative administration of high dose of Dexamethasone (≥ 0,2 mg/Kg or ≥ 15 mg), or a corresponding dose of a systemic glucocorticoid. MEASUREMENTS: Primary outcomes were postoperative pain measured in 0-100 mm VAS score at 24 h after surgery upon rest and movement. Secondary outcomes were postoperative pain 0-100 mm VAS score 48 h after surgery, postoperative rescue analgesic requirement, postoperative nausea and vomiting (PONV), relevant adverse events. MAIN RESULTS: 47 RCT's were included (3943 patients). The Mean Difference (MD) of 100 mm VAS scores for pain at rest 24 h after surgery was -6.18 mm 95% CI [-8.53, -3.83], at motion -8.86 mm 95% CI [-11.82, -5.89]. Opioid analgesic requirements evaluated in Oral Morphine Equivalents (OME) was -10.00 mg 95% CI [-13.65, -6.34]. PONV events Odds Ratio of 0.29 95%CI [0.24, 0.36]. Major adverse events OR was 0.88 95% CI [0.65, 1.19]. Minor adverse events OR 1.29 95% CI [0.86, 1.92]. CONCLUSION: High doses of glucocorticoids are one of the many possible tools available in multimodal postoperative analgesia, possibly reducing opioids consumption and recurrence of PONV but with no relevant effects in terms of reduction of postoperative VAS score. Available data show a safe therapeutic profile, without increase adverse events. PROTOCOL REGISTRATION: CRD42020137119.

Regional anaesthesia for ambulatory surgery.

Regional anaesthesia (RA) has an important and ever-expanding role in ambulatory surgery. Specific practices vary depending on the preferences and resources of the anaesthesia team and hospital setting. It is used for various purposes, including as primary anaesthetic technique for surgery but also as postoperative analgesic modality. The limited duration of action of currently available local anaesthetics limits their application in postoperative pain control and enhanced recovery. The search for the holy grail of regional anaesthetics continues. Current evidence suggests that a peripheral nerve block performed with long-acting local anaesthetics in combination with intravenous or perineural dexamethasone gives the longest and most optimal sensory block. In this review, we outline some possible blocks for ambulatory surgery and additives to perform RA. Moreover, we give an update on local anaesthesia drugs and adjuvants, paediatric RA in ambulatory care and discuss the impact of RA by COVID-19.

Pain management after cardiac surgery via median sternotomy: A systematic review with procedure-specific postoperative pain management (PROSPECT) recommendations.

BACKGROUND: Pain after cardiac surgery via median sternotomy can be difficult to treat, and if inadequately managed can lead to respiratory complications, prolonged hospital stays and chronic pain. OBJECTIVES: To evaluate available literature and develop recommendations for optimal pain management after cardiac surgery via median sternotomy. DESIGN: A systematic review using PROcedure-SPECific Pain Management (PROSPECT) methodology. ELIGIBILITY CRITERIA: Randomised controlled trials and systematic reviews published in the English language until November 2020 assessing postoperative pain after cardiac surgery via median sternotomy using analgesic, anaesthetic or surgical interventions. DATA SOURCES: PubMed, Embase and Cochrane Databases. RESULTS: Of 319 eligible studies, 209 randomised controlled trials and three systematic reviews were included in the final analysis. Pre-operative, intra-operative and postoperative interventions that reduced postoperative pain included paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), intravenous magnesium, intravenous dexmedetomidine and parasternal block/infiltration. CONCLUSIONS: The analgesic regimen for cardiac surgery via sternotomy should include paracetamol and NSAIDs, unless contraindicated, administered intra-operatively and continued postoperatively. Intra-operative magnesium and dexmedetomidine infusions may be considered as adjuncts particularly when basic analgesics are not administered. It is not clear if combining dexmedetomidine and magnesium would provide superior pain relief compared with either drug alone. Parasternal block/surgical site infiltration is also recommended. However, no basic analgesics were used in the studies assessing these interventions. Opioids should be reserved for rescue analgesia. Other interventions, including cyclo-oxygenase-2 specific inhibitors, are not recommended because there was insufficient, inconsistent or no evidence to support their use and/or due to safety concerns.

Introduction and history of anaesthesia-induced neurotoxicity and overview of animal models.

Brain development is initiated at around 3 weeks of gestation. The peak velocity of brain weight gain occurs around birth, with the neural circuitry subsequently being refined until at least 20 years of age. Antenatal and postnatal general anaesthesia suppresses neuronal firing during this critical period and may therefore impair brain development, referred to as "anaesthesia-induced neurotoxicity". Whilst up to 1% of children are exposed to general anaesthesia antenatally (e.g., as an innocent bystander to maternal laparoscopic appendectomy), 15% of children under 3 years of age undergo general anaesthesia postnatally (e.g., otorhinolaryngologic surgery). In this article, the history of preclinical and clinical research in anaesthesia-induced neurotoxicity will be reviewed, starting from the pioneering preclinical study in 1999 until the most recent systematic reviews. The mechanisms of anaesthesia-induced neurotoxicity are introduced. Finally, an overview of the methods used in preclinical studies will be provided, with a comparison of the different animal models that have been employed to investigate this phenomenon.

Current status of the combined spinal-epidural technique in obstetrics and surgery.

Epidural and spinal blocks are well-accepted neuraxial techniques but both have several disadvantages. Combined spinal-epidural (CSE) can combine the best features of both techniques and reduce or eliminate these disadvantages. It provides the rapidity, density, and reliability of subarachnoid block with the flexibility of catheter epidural technique to extend the duration of anesthesia/analgesia (and to improve spinal block). It is an excellent technique for determining minimum intrathecal drug doses. Although most commonly employed in obstetric practice, CSE is also used in a wide variety of non-obstetric surgical procedures including orthopedic, vascular, gynecological, urological, and general surgical procedures. The needle-through-needle technique remains the most commonly used method to perform CSE. Several technical variations including Sequential CSE and Epidural Volume Extention (EVE) are commonly used particularly in obstetric and high-risk patients such as those with cardiac disease where a slower onset of sympathetic block is desirable. The risks of complications such as epidural catheter migration through the dural hole, neurological complications, and subarachnoid spread of epidurally administered drugs are possible but have not been a clinically relevant problem in the 40+ years of their existence. In obstetrics, CSE is used for labor pain because it produces rapid-onset analgesia with reduced local anesthetic consumption and less motor block. The epidural catheter placed as part of a CSE is more reliable than a catheter placed as part of a conventional epidural. Less breakthrough pain throughout labor is noted and fewer catheters require replacing. Side effects of CSE include greater potential for hypotension and more fetal heart rate abnormalities. CSE is also used for cesarean delivery. The main purpose is to decrease the spinal dose so that spinal-induced hypotension can be reduced. However, reducing the spinal dose requires an epidural catheter to avoid intra-operative pain when surgery is prolonged.

Effects of cumulative duration of repeated anaesthesia exposure on foetal brain development in the ovine model.

OBJECTIVE: Anaesthesia is required in 0.4-1% of pregnant women, and prolonged and repeated exposures to anaesthesia may be required. It is unknown whether these exposures may result in foetal neurotoxicity in humans. As sheep have a gestation comparable to that of humans, the objective of this study was to analyse the neurodevelopmental outcome of ovine foetuses that had been exposed in utero to repeated and prolonged anaesthesia. DESIGN: Randomized controlled preclinical study. SETTING: Anaesthesia for non-obstetric surgery during pregnancy. ANIMALS: Twenty-four healthy pregnant Swifter ewes. INTERVENTIONS: The ewes were randomized to no anaesthesia exposure (control-group), single exposure (at gestational age 68-70 days), or repeated exposure (at gestational age 68-70 days and 96-98 days) to 2.5 h of sevoflurane anaesthesia and maternal laparotomy. All lambs were delivered at approximately term gestation (gestational age: 140-143 days). MEASUREMENTS: The primary outcome was neuron density in the frontal cortex 24 h after birth for the control-group versus the repeated-exposure-group. Key secondary outcome was the time needed to achieve the milestone of standing. Secondary outcomes included other neurobehavioural assessments (e.g., motoric milestones) and histological parameters quantified in multiple brain regions (neuron density, total cell density, proliferation, inflammation, synaptogenesis, astrocytes and myelination). MAIN RESULTS: Neuron density in the frontal cortex did not differ between groups (mean ±â€¯standard deviation: control-group: 403 ±â€¯39, single-exposure group: 436 ±â€¯23 and repeated-exposure-group: 403 ±â€¯40 neurons/mm2, control-group versus repeated-exposure-group: p = 0.986, control-group versus single-exposure-group: p = 0.097). No significant difference was observed for the time needed to achieve the milestone of standing. Only very limited differences were observed for other histological outcome parameters and neurobehavioural assessments. CONCLUSIONS: There is no evidence for foetal neuronal injury or neurobehavioural impairments after a cumulative duration of 5 h repetitive prenatal anaesthesia in sheep.

Additive or synergistic analgesic effect of metamizole on standard pain treatment at home after arthroscopic shoulder surgery: A randomised controlled superiority trial.

BACKGROUND: There is growing evidence that the analgesic effect of metamizole is mediated at least partly by central mechanisms, including the endocannabinoid/endovanilloid system. Consequently, metamizole may have additive or even synergistic analgesic effects with paracetamol and nonsteroidal anti-inflammatory drugs (NSAID). OBJECTIVE: This study aimed to assess if triple therapy with metamizole, ibuprofen and paracetamol (MIP) is superior to double therapy with ibuprofen and paracetamol (i.p.) in treating pain at home after ambulatory arthroscopic shoulder surgery. DESIGN/SETTING/PATIENTS/INTERVENTION: In this double-blind, controlled, high-volume single centre, superiority trial, 110 patients undergoing elective ambulatory arthroscopic shoulder surgery were randomised to receive either MIP ( n  = 55) or i.p. ( n  = 55) orally for 4 days between December 2019 and November 2021. Pain intensity at movement and rest, using a numeric rating scale (NRS), perceived pain relief, use of rescue medication and adverse effects of study medication were recorded at the post-anaesthesia care unit (PACU) and on postoperative day (POD) 1 to 4 and 7. Quality of Recovery (QoR) and satisfaction with study medication were measured at POD 7 with telephone follow-up. MAIN OUTCOME MEASURE: The primary outcome measure was postoperative pain intensity on movement measured by an 11-point NRS (where 0 = no pain and 10 = worst pain imaginable) on POD 1. RESULTS: For the primary outcome, superiority of MIP in reducing postoperative pain at movement on POD 1 was not confirmed: mean difference NRS [95% confidence interval (CI), -0.08 (-1.00 to 0.84)]. For pain on movement and at rest, no significant differences were found between groups in the PACU nor on POD 1 to 4 or day 7. Nausea was reported significantly more frequently in the metamizole group (22.6 vs. 58.5; P  < 0.001). Other adverse effects of study medication, rescue opioid consumption, perceived pain relief, QoR at POD 7, and overall patient satisfaction were similar in both groups. CONCLUSION: Clinically, triple oral treatment with metamizole, paracetamol and ibuprofen is not superior to oral paracetamol and ibuprofen in multimodal pain treatment at home after ambulatory arthroscopic shoulder surgery. TRIAL REGISTRATION: European Union Clinical Trials Register 2019-002801-23 and Clinicaltrials.gov NCT04082728.

Arterial to end-tidal CO2 gradients during isocapnic hyperventilation.

Isocapnic hyperventilation (ICHV) is occasionally used to maintain the end-expired CO2 partial pressure (PETCO2) when the inspired CO2 (PICO2) rises. Whether maintaining PETCO2 with ICHV during an increase of the PICO2 also maintains arterial PCO2 (PaCO2) remains poorly documented. 12 ASA PS I-II subjects undergoing a robot-assisted radical prostatectomy (RARP) (n = 11) or cystectomy (n = 1) under general endotracheal anesthesia with sevoflurane in O2/air (40% inspired O2) were enrolled. PICO2 was sequentially increased from 0 to 0.5, 1.0, 1.5 and 2% by adding CO2 to the inspiratory limb of the circle system, while increasing ventilation to a target PETCO2 of 4.7-4.9% by adjusting respiratory rate during controlled mechanical ventilation. Pa-ETCO2 gradients were determined after a 15 min equilibration period at each PICO2 level and compared using ANOVA. Mean (standard deviation) age, height, and weight were 66 (6) years, 171 (6) cm, and 75 (8) kg, respectively. Capnograms were normal and hemodynamic parameters remained stable. PETCO2 could be maintained within 4.7-4.9% in all subjects at all times except in 1 subject with 1.5% PICO2 and 5 subjects with 2.0% PICO2; data from the one subject in whom both 1.5 and 2.0% PICO2 resulted in PETCO2 > 5.1% were excluded from analysis. Pa-ETCO2 gradients did not change when PICO2 increased. The effect of a modest rise of PICO2 up to 1.5% on PETCO2 during RARP can be readily overcome by increasing ventilation without altering the Pa-ETCO2 gradients. At higher PICO2, airway pressures may become a limiting factor, which requires further study.

EAES rapid guideline: systematic review, meta-analysis, GRADE assessment, and evidence-informed European recommendations on appendicitis in pregnancy.

BACKGROUND: Clinical practice recommendations for the management of acute appendicitis in pregnancy are lacking. OBJECTIVE: To develop an evidence-informed, trustworthy guideline on the management of appendicitis in pregnancy. We aimed to address the questions of conservative or surgical management, and laparoscopic or open surgery for acute appendicitis. METHODS: We performed a systematic review, meta-analysis, and evidence appraisal using the GRADE methodology. A European, multidisciplinary panel of surgeons, obstetricians/gynecologists, a midwife, and 3 patient representatives reached consensus through an evidence-to-decision framework and a Delphi process to formulate the recommendations. The project was developed in an online authoring and publication platform (MAGICapp). RESULTS: Research evidence was of very low certainty. We recommend operative treatment over conservative management in pregnant patients with complicated appendicitis or appendicolith on imaging studies (strong recommendation). We suggest operative treatment over conservative management in pregnant patients with uncomplicated appendicitis and no appendicolith on imaging studies (weak recommendation). We suggest laparoscopic appendectomy in patients with acute appendicitis until the 20th week of gestation, or when the fundus of the uterus is below the level of the umbilicus; and laparoscopic or open appendectomy in patients with acute appendicitis beyond the 20th week of gestation, or when the fundus of the uterus is above the level of the umbilicus, depending on the preference and expertise of the surgeon. CONCLUSION: Through a structured, evidence-informed approach, an interdisciplinary panel provides a strong recommendation to perform appendectomy for complicated appendicitis or appendicolith, and laparoscopic or open appendectomy beyond the 20th week, based on the surgeon's preference and expertise. GUIDELINE REGISTRATION NUMBER: IPGRP-2022CN210.

Regional anaesthesia: what surgical procedures, what blocks and availability of a "block room"?

PURPOSE OF REVIEW: With an expected rise in day care procedures with enhanced recovery programs, the use of specific regional anaesthesia can be useful. In this review, we will provide insight in the used regional block and medication so far known and its applicability in a day care setting. RECENT FINDINGS: Regional anaesthesia has been improved with the aid of ultrasound-guided placement. However, it is not commonly used in the outpatient setting. Old, short acting local anaesthetics have found a second life and may be especially beneficial in the ambulatory setting replacing more long-acting local anaesthetics such as bupivacaine.To improve efficiency, a dedicated block room may facilitate the performance of regional anaesthesia. However, cost-efficacy for improved operating time, patient care and hospital efficiency has to be established. SUMMARY: Regional anaesthesia has proven to be beneficial in ambulatory setting. Several short acting local anaesthetics are favourable over bupivacaine in the day care surgery. And if available, there are reports of the benefit of an additional block room used in a parallel (monitored) care of patients.

Neurodevelopmetal effects of maternal blood pressure management with noradrenaline during general anaesthesia for nonobstetric surgery in the pregnant rabbit model.

In pregnant women, anaesthesia-induced hypotension is commonly treated using phenylephrine or noradrenaline, the rationale being to maintain uterine perfusion pressure and thereby uterine blood flow. Evidence for this strategy during general anaesthesia for nonobstetric surgery is absent. To analyse the effects of treating anaesthesia-induced hypotension with noradrenaline on brain development of rabbit foetuses of mothers subjected to general anaesthesia for nonobstetric surgery. We hypothesised that treatment of maternal hypotension would improve foetal outcomes. Randomised controlled laboratory study using 21 pregnant rabbits (does) at 28 days of gestation. Two hours of sevoflurane anaesthesia for a laparotomy without treatment of anaesthesia-induced hypotension (hypotension group) or with maintaining maternal mean arterial pressure above 80% of the awake value using noradrenaline (noradrenaline group). In the control group, does remained untouched. At term, all pups were delivered by caesarean section. One day later, the neurobehaviour of the pups was assessed and brains were harvested. Neuron density in the frontal cortex for the comparison of noradrenaline groups versus hypotension groups was the primary outcome; the neurobehavioural scores and other histological outcomes were secondary outcomes. In the noradrenaline groups and hypotension groups, neuron density in the frontal cortex was similar (1181 ±â€Š162 versus 1189 ±â€Š200 neurons mm-2, P  = 0.870). However, significantly less foetal survival, lower sensory scores in neurobehavioural assessment and less proliferation were observed in the noradrenaline group when compared with the hypotension group. Neuron densities in other regions, total cell densities, biometrics and synaptogenesis were not affected. There were no differences between the control group and hypotension group. During general anaesthesia for nonobstetric surgery in rabbits, treatment of anaesthesia-induced hypotension using noradrenaline did not affect neuron densities but was associated with impaired foetal outcomes according to several secondary outcome parameters. Further studies are needed to investigate any clinical relevance and to determine the target blood pressure in pregnant women during general anaesthesia.KEY POINTSIn pregnant women, anaesthesia-induced hypotension is commonly treated using phenylephrine or noradrenaline, with the rationale to maintain uterine perfusion pressure and thereby uterine blood flow.Evidence for this strategy during general anaesthesia for nonobstetric surgery is absent.We investigated the effects of treating anaesthesia-induced hypotension with noradrenaline on the brain development of rabbit foetuses, of mothers subjected to general anaesthesia for nonobstetric surgery.We hypothesised that treatment of maternal hypotension would improve foetal outcomes.Neuron densities were similar but significantly less foetal survival, impaired neurobehaviour and less proliferation were observed after treatment of anaesthesia-induced hypotension with noradrenaline, compared with untreated hypotension.

Memsorb™, a novel CO2 removal device part II: in vivo performance with the Zeus IE®.

Memsorb™ (DMF Medical, Halifax, Canada) is a novel device based upon membrane oxygenator technology designed to eliminate CO2 from exhaled gas when using a circle anesthesia circuit. Exhaled gases pass through semipermeable hollow fibers and sweep gas flowing through these fibers creates a diffusion gradient for CO2 removal. In vivo Memsorb™ performance was tested during target-controlled closed-circuit anesthesia (TCCCA) with desflurane in O2/air using a Zeus IE® anesthesia workstation (Dräger, Lübeck, Germany). Clinical care protocols for using this novel device were guided by in vitro performance results from a prior study (submitted simultaneously). After IRB approval, written informed consent was obtained from 10 ASA PS I-III patients undergoing robot-assisted radical prostatectomy. TCCCA targets were 39% inspired O2 concentration (FIO2) and 5.0% end-expired desflurane concentration (FETdes). Minute ventilation (MV) was adjusted to maintain 4.5-6.0% FETCO2. The O2/air (40% O2) sweep flow into the Memsorb™ was manually adjusted in an attempt to keep inspired CO2 concentration (FICO2) ≤ 0.8%. The following data were collected: FIO2, FETdes, FICO2, FETCO2, MV, fresh gas flow (FGF, O2 and air), sweep flow, and cumulative desflurane usage (Vdes). Vdes of the Zeus IE®-Memsorb™ combination was compared with historical Vdes observed in a previous study when soda lime (DrägerSorb 800 +) was used. Results are reported as median and inter-quartiles. A combination of manually adjusting sweep flow (26 [21,27] L/min) and MV sufficed to maintain FICO2 ≤ 0.8% and FETCO2 ≤ 6.0%, except in one patient in whom the target Zeus IE® FGF had to be increased to 0.7 L/min for 6 min. FIO2 and FETdes were maintained close to their targets. Zeus IE® FGF after 5 min was 0 [0,0] mL/min. Average Vdes after 50 min was higher with Memsorb™ (20.3 mL) compared to historical soda lime canister data (12.3 mL). During target-controlled closed-circuit anesthesia in patients undergoing robot-assisted radical prostatectomy, the Memsorb™ maintained FICO2 ≤ 0.8% and FETCO2 ≤ 6.0%, and FIO2 remained close to target. Modest amounts of desflurane were lost with the use of the Memsorb™. The need for adjustments of sweep flow, minute ventilation, and occasionally Zeus IE® FGF indicates that the Memsorb™ system should preferentially be integrated into an automated closed-loop system.