Patients' perioperative experiences of an opioid-free versus opioid-based care pathway for laparoscopic bariatric surgery: A qualitative study.

Background: Despite recent evidence supporting the adoption of opioid-free anaesthetic and analgesic alternatives in the perioperative context, opioid-based regimens remain standard of care. There is limited knowledge about the patients' perioperative experiences of bariatric surgery, with no study yet investigating their experiences within an opioid-free care pathway. Objective: We aimed to describe similarities and differences in patients' perioperative experiences of undergoing bariatric surgery with either an opioid-free or opioid-based care pathway. Design: A qualitative interview study. Setting: A strategic sample of patients enrolled in an ongoing randomized controlled trial investigating the effects of opioid-free anaesthesia for bariatric surgery were recruited. In the randomized controlled trial, participants were randomized to either opioid-based anaesthesia or opioid-free anaesthesia, including transcutaneous electrical nerve stimulation as primary postoperative pain management. Participants: Twenty patients were interviewed 3 months after surgery: 10 participants in the opioid-free group versus 10 in the opioid-based group. Methods: Semi-structured interviews were conducted between December 2020 and February 2022 and analysed with qualitative content analysis. Results: The analysis yielded four categories and 12 subcategories. In Category 1, participants shared diverse emotions before surgery, including anticipation of a healthier life, but also apprehensions and feelings of failure. In Category 2, describing liminality of general anaesthesia, there were similar descriptions of struggling to remember the anaesthesia induction and struggling to surface when recovering from anaesthesia. However, some participants in the opioid-free group shared descriptions of struggling to keep control, describing accentuated memories of the anaesthesia induction. Category 3, managing your pain, showed similar experiences and strategies but different narrations of pain management, with the opioid-free group stating that transcutaneous electrical nerve stimulation works but not when it really hurts, and the opioid-based group describing confidence in but awareness of opioids. Throughout the overall perioperative time period, participants acknowledged Category 4, a patient-professional presence, stating that preparations boost the feeling of confidence before surgery and that they felt confidence in a vulnerable situation although vulnerability challenges communication. Conclusions: We highlighted the overall similarities in perioperative experiences of patients undergoing bariatric surgery. However, the differences in experiences during opioid-free anaesthesia induction need to be addressed in further implementation and research studies investigating strategies to reduce the sense of loss of control. More research is needed to facilitate the implementation of opioid-free treatment strategies into clinical practice and improve the patient care experience.

High-frequency, high-intensity transcutaneous electrical nerve stimulation compared with opioids for pain relief after gynecological surgery: a systematic review and meta-analysis.

OBJECTIVES: Opioids are important for postoperative analgesia but their use can be associated with numerous side effects. Transcutaneous electrical nerve stimulation (TENS) has been used for acute pain treatment and has dose-dependent analgesic effects, and therefore presents an alternative to intravenous (iv) opioids for postoperative pain relief. The aim of this meta-analysis was to compare high-frequency, high-intensity (HFHI or intense) TENS to iv opioids with regard to postoperative pain intensity, recovery time in the Post Anesthesia Care Unit (PACU) and opioid consumption after elective gynecological surgery. METHODS: We searched Medline, Embase, Web of Science, Cochrane, Amed and Cinahl for RCTs and quasi-experimental studies (2010-2022), and WHO and ClinicalTrials.gov for ongoing/unpublished studies. Meta-analysis and subsequent Trial Sequential Analysis (TSA) was performed for all stated outcomes. Quality of evidence was assessed according to GRADE. RESULTS: Only three RCTs met the inclusion criteria (362 participants). The surgical procedures involved surgical abortion, gynecologic laparoscopy and hysteroscopy. The applied TENS frequency was 80 Hz and intensity 40-60 mA. There was no difference in pain intensity according to Visual Analogue Scale (VAS) at discharge from PACU between the TENS and opioid group (MD VAS -0.15, 95 % CI -0.38 to 0.09) (moderate level of evidence). Time in PACU was significantly shorter in the TENS group (MD -15.2, 95 % -22.75 to -7.67), and this finding was manifested by TSA (high-level of evidence). Opioid consumption in PACU was lower in the TENS group (MD Morphine equivalents per patient mg -3.42, 95 % -4.67 to -2.17) (high-level of evidence). CONCLUSIONS: There was no detectable difference in postoperative pain relief between HFHI TENS and iv opioids after gynecological surgery. Moreover, HFHI TENS decreases recovery time and opioid consumption in PACU. HFHI TENS may be considered an opioid-sparing alternative for postoperative pain relief after gynecological surgery. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021231048.

Circulating concentrations of glycocalyx degradation products in preeclampsia.

Background and Objectives: Preeclampsia is a multisystem disorder that affects maternal endothelium. The glycocalyx lines and protects the endothelial surface. In severe systemic diseases, like sepsis, it is shed and glycocalyx degradation products can be detected in increased concentrations in plasma. The aim of this study was to compare circulating concentrations of glycocalyx degradation products in degrees of preeclampsia severity. Study design: In this observational study, we included women from the South African PROVE biobank. Women were divided into normotensive controls, women with preeclampsia without end-organ complications, women with a single end-organ complication and women with multiple end-organ complications. Plasma samples taken at inclusion after diagnosis (preeclampsia cases) or at admission for delivery (normotensive controls) were analyzed with ELISA for syndecan-1, hyaluronic acid and thrombomodulin and compared between groups. Results: Women with preeclampsia (n = 47) had increased plasma concentrations of hyaluronic acid (100.3 ng/ml IQR 54.2-204 vs. 27.0 ng/ml IQR (13.5-66.6), p < 0,001) and thrombomodulin (4.22 ng/ml IQR 3.55-5.17 vs. 3.49 ng/ml IQR 3.01-3.68, p = 0.007) but not syndecan-1 compared with normotensive women (n = 10). There were no differences in plasma concentration in any of these biomarkers in women with preeclampsia with no end-organ complications (n = 10) compared with women with preeclampsia and one end-organ complication (n = 24). Women with preeclampsia with two or more end-organ complications (n = 13) had increased plasma concentrations of thrombomodulin (5.46 ng/ml, IQR 4.85-7.83 vs. 4.66 ng/ml, IQR 3.45-4.88, p = 0.042) compared with women with preeclampsia and no end-organ complications. Conclusion: Thrombomodulin was associated with disease severity and may be valuable for risk-stratifying women with preeclampsia.

Total opioid-free general anaesthesia can improve postoperative outcomes after surgery, without evidence of adverse effects on patient safety and pain management: A systematic review and meta-analysis.

BACKGROUND: Opioid-based treatment is used to manage stress responses during surgery and postoperative pain. However, opioids have both acute and long-term side effects, calling for opioid-free anaesthetic strategies. This meta-analysis compares adverse events, postoperative recovery, discharge time from post-anaesthesia care unit, and postoperative pain, nausea, vomiting, and opioid consumption between strict opioid-free and opioid-based general anaesthesia. METHODS: We conducted a systematic review and meta-analysis. We searched PubMed, Embase, Cinahl, Cochrane Library, selected reference lists, and Google Scholar. We included randomised controlled trials (RCTs) published between January 2000 and February 2021 with at least one opioid-free study arm, i.e. no opioids administered preoperatively, during anaesthesia induction, before skin closure, or before emergence from anaesthesia. RESULTS: The study comprised 1934 patients from 26 RCTs. Common interventions included laparoscopic gynaecological surgery, upper gastrointestinal surgery, and breast surgery. There is firm evidence that opioid-free anaesthesia significantly reduced adverse postoperative events (OR 0.32, 95% CI 0.22 to 0.46, I2  = 56%, p < 0.00001), mainly driven by decreased nausea (OR 0.27, (0.17 to 0.42), p < 0.00001) and vomiting (OR 0.22 (0.11 to 0.41), p < 0.00001). Postoperative opioid consumption was significantly lower in the opioid-free group (-6.00 mg (-8.52 to -3.48), p < 0.00001). There was no significant difference in length of post-anaesthesia care unit stay and overall postoperative pain between groups. CONCLUSIONS: Opioid-free anaesthesia can improve postoperative outcomes in several surgical settings without evidence of adverse effects on patient safety and pain management. There is a need for more evidence-based non-opioid anaesthetic protocols for different types of surgery as well as postoperative phases.

Opioid consumption in patients undergoing Roux-en-Y bariatric surgery compared with population controls with and without obesity.

BACKGROUND: Patients with obesity are prescribed more opioids than the general population. OBJECTIVES: To compare opioid consumption in patients with obesity who underwent Roux-en-Y bariatric surgery (RYGB) with population controls with and without obesity, not undergoing bariatric surgery, and to identify characteristics associated with opioid use. SETTING: This study included all patients with a principal diagnosis of obesity, aged 18-72 years, with a RYGB surgical code in the Swedish Patient Register between 2007 and 2013. METHODS: RYGB patients (n = 23,898) were age- and sex-matched with 1 control patient with obesity (n = 23,898) and 2 population controls without obesity (n = 46,064). Participants were classified as nonconsumers and consumers based on their opioid dispensations during the 12 months before baseline. Opioid consumption was assessed for 24 months. RESULTS: Nonconsumers. Within 24 months, a significantly higher proportion of RYGB patients (16.6%) started using opioids compared with the controls with obesity (14.3%, P < .0001) and population controls (5.4%, P < .0001). RYGB patients and controls with obesity had higher median daily intake of opioid morphine equivalent (MEQ) (2.8 mg/d) than population controls (2.5 mg/d, P < .0001). Consumers. Within 24 months, the proportion of RYGB patients and controls with obesity that was using opioids were similar (53.1% and 53.4%), but higher compared to population controls (38.0%, P < .0001). The median daily opioid MEQ was higher among RYGB patients than in population controls (10.5 versus 7.8 mg/d, P < .0001). RYGB patients, overall, had higher incidence of bowel surgery and cholecystectomy compared with controls with obesity and population controls, leading to prolonged opioid use in this group. Opioid consumption in general was associated with chronic pain and psychiatric disorder, which were more common in patients with obesity than in the population controls. CONCLUSION: RYGB surgery increased the risk of prolonged opioid use in patients with obesity who were nonconsumers before surgery but had no effect on overall opioid use among prior consumers. RYGB-associated complications requiring surgery influenced opioid use for both nonconsumers and consumers. Regular reassessments of pain mechanisms and specific treatment owing to type of pain could prevent unnecessary opioid use in this patient group.

Study protocol: establishment of a multicentre pre-eclampsia database and biobank in Sweden: GO PROVE and UP MOST, a prospective cohort study.

INTRODUCTION: Pre-eclampsia, a multisystem disorder in pregnancy, is one of the most common causes of maternal morbidity and mortality worldwide. However, we lack methods for objective assessment of organ function in pre-eclampsia and predictors of organ impairment during and after pre-eclampsia. The women's and their partners' experiences of pre-eclampsia have not been studied in detail. To phenotype different subtypes of the disorder is of importance for prediction, prevention, surveillance, treatment and follow-up of pre-eclampsia.The aim of this study is to set up a multicentre database and biobank for pre-eclampsia in order to contribute to a safer and more individualised treatment and care. METHODS AND ANALYSIS: This is a multicentre cohort study. Prospectively recruited pregnant women ≥18 years, diagnosed with pre-eclampsia presenting at Sahlgrenska University Hospital, Uppsala University Hospital and at Södra Älvsborgs Hospital, Sweden, as well as normotensive controls are eligible for participation. At inclusion and at 1-year follow-up, the participants donate biosamples that are stored in a biobank and they are also asked to participate in various organ-specific evaluations. In addition, questionnaires and interviews regarding the women's and partner's experiences are distributed at follow-up. ETHICS AND DISSEMINATION: By creating a database and biobank, we will provide the means to explore the disorder in a broader sense and allow clinical and laboratory discoveries that can be translated to clinical trials aiming at improved care of women with pre-eclampsia. Further, to evaluate experiences and the psychological impact of being affected by pre-eclampsia can improve the care of pregnant women and their partners. In case of incidental pathological findings during examinations performed, they will be handled in accordance with clinical routine. Data are stored in a secure online database. Biobank samples are identified through the women's personal identification number and pseudonymised after identification in the biobank before analysis.This study was approved by the regional ethical review board in Gothenburg on 28 December 2018 (approval number 955-18) and by the Swedish Ethical Review Authority on 27 February 2019 (approval number 2019-00309).Results from the study will be published in international peer-reviewed journals. TRIAL REGISTRATION NUMBER: ISRCTN13060768.

Signs of neuroaxonal injury in preeclampsia-A case control study.

BACKGROUND: Cerebral injury is a common cause of maternal mortality due to preeclampsia and is challenging to predict and diagnose. In addition, there are associations between previous preeclampsia and stroke, dementia and epilepsy later in life. The cerebral biomarkers S100B, neuron specific enolase, (NSE), tau protein and neurofilament light chain (NfL) have proven useful as predictors and diagnostic tools in other neurological disorders. This case-control study sought to determine whether cerebral biomarkers were increased in cerebrospinal fluid (CSF) as a marker of cerebral origin and potential cerebral injury in preeclampsia and if concentrations in CSF correlated to concentrations in plasma. METHODS: CSF and blood at delivery from 15 women with preeclampsia and 15 women with normal pregnancies were analysed for the cerebral biomarkers S100B, NSE, tau protein and NfL by Simoa and ELISA based methods. MRI brain was performed after delivery and for women with preeclampsia also at six months postpartum. RESULTS: Women with preeclampsia demonstrated increased CSF- and plasma concentrations of NfL and these concentrations correlated to each other. CSF concentrations of NSE and tau were decreased in preeclampsia and there were no differences in plasma concentrations of NSE and tau between groups. For S100B, serum concentrations in preeclampsia were increased but there was no difference in CSF concentrations of S100B between women with preeclampsia and normal pregnancy. CONCLUSION: NfL emerges as a promising circulating cerebral biomarker in preeclampsia and increased CSF concentrations point to a neuroaxonal injury in preeclampsia, even in the absence of clinically evident neurological complications.

Effects of high-frequency, high-intensity transcutaneous electrical nerve stimulation versus intravenous opioids for pain relief after hysteroscopy: a randomized controlled study.

OBJECTIVE: To compare the time spent in the Post-Anesthesia Care Unit (PACU) and the pain-relieving effects of treatment with high-frequency, high-intensity transcutaneous electrical nerve stimulation (TENS) or intravenous (IV) opioids after hysteroscopy. METHODS: All patients who postoperatively reported a visual analogue scale (VAS) pain score of ≥3 were included in the study. TENS treatment was given with a stimulus intensity between 40 and 60 mA for 1 minute and repeated once if there was insufficient pain relief. In the opioid group, a fractionated dose of 5 mg morphine was administered. If the patient reported insufficient pain relief after the assigned treatment, the patient was reassigned to the other treatment group. RESULTS: Seventy-four women were randomized to TENS (n=38) or IV opioids (n=36) for treatment. Both groups reported significant pain relief after discharge from the PACU, with a decrease of VAS scores from 5.6 to 1.4 in the TENS group (P<0.001) and 5.1 to 1.3 in the opioid group (P<0.001). There were no significant differences between the groups. When only the responders in both groups, i.e., patients with VAS scores of <3 on respectively assigned treatments, were compared, the TENS responders (n=22) were found to have spent a significantly shorter time in the PACU (91 vs. 69 minutes, P=0.013) compared to the opioid responders (n=20). CONCLUSION: Using TENS as first line of pain relief may reduce the need for postoperative opioids. In addition, TENS appears preferable as the first line of treatment due to its association with a shorter time spent in the PACU if the patient responds to the treatment. TRIAL REGISTRATION: Västra Götalandsregionen Identifier: 211261.

Intraperitoneal ropivacaine reduces time interval to initiation of chemotherapy after surgery for advanced ovarian cancer: randomised controlled double-blind pilot study.

BACKGROUND: Advanced-stage ovarian cancer has a poor prognosis; surgical resection with the intent to leave no residual tumour followed by adjuvant chemotherapy is the standard treatment. Local anaesthetics (LA) have anti-inflammatory and analgesic effects. We hypothesised that intraperitoneal LA (IPLA) would lead to improved postoperative recovery, better pain relief, and earlier start of chemotherapy. METHODS: This was a prospective, randomised, double-blind, placebo-controlled pilot study in 40 women undergoing open abdominal cytoreductive surgery. Patients were randomised to receive either intraperitoneal ropivacaine (Group IPLA) or saline (Group Placebo) perioperatively. Except for study drug, patients were treated similarly. Intraoperatively, ropivacaine 2 mg ml-1 or 0.9% saline was injected thrice intraperitoneally, and after operation via a catheter and analgesic pump into the peritoneal cavity for 72 h. Postoperative pain, time to recovery, home discharge, time to start of chemotherapy, and postoperative complications were recorded. RESULTS: No complications from LA administration were recorded. Pain intensity and rescue analgesic consumption were similar between groups. Time to initiation of chemotherapy was significantly shorter in Group IPLA (median 21 [inter-quartile range 21-29] vs 29 [inter-quartile range 21-40] days; P=0.021). Other parameters including time to home readiness, home discharge and incidence, and complexity of postoperative complications were similar between the groups. CONCLUSIONS: Intraperitoneal ropivacaine during and for 72 h after operation after cytoreductive surgery for ovarian cancer is safe and reduces the time interval to initiation of chemotherapy. Larger studies are warranted to confirm these initial findings. CLINICAL TRIAL REGISTRATION: NCT02256228.

Effects of a home-based exercise program on the insulin-like growth factor axis in patients operated for colorectal cancer in Sweden: Results from the randomised controlled trial PHYSSURG-C.

OBJECTIVES: We report results from a subgroup within the ongoing PHYSSURG-C trial with the aim to examine effects of exercise on IGF-1 and IGFBP-3 in patients undergoing colorectal cancer surgery. DESIGN: Randomised controlled trial. SETTING: A Swedish university hospital. PARTICIPANTS: Between 2015 and 2016, 217 patients were enrolled (I = 106, C = 111), with 122 patients that had given blood samples at baseline and at least at one follow-up (I = 51, C = 71). Patients 20 year or older with colorectal cancer were eligible. Exclusion criteria were emergency surgery, local surgery, language problems or inability to perform intervention. INTERVENTIONS: Patients were computer-randomised to either a daily home-based aerobic exercise intervention (I), or to usual care (C). The intervention lasted two weeks before surgery and four weeks after discharge from hospital and consisted of medium-intensity aerobic exercise and inspiratory muscle training. Circulating concentrations of IGF-1 and IGFBP-3 were determined by blinded personnel at baseline, time of surgery and 4-6 weeks postoperatively. PRIMARY AND SECONDARY OUTCOME MEASURES: The outcome of this subpopulation report was change in IGF-1/IGFBP-3 ratio, IGF-1 and IGFBP-3 concentrations from baseline to surgery, and 4-6 weeks postoperatively. RESULTS: The IGF-1/IGFBP-3 ratio increased from baseline to surgery by 11% in I and 8% in C with no difference between groups (I vs. C: 1.04, 95%CI: 0.97-1.11; p = 1.000). Postoperative change was 5% in I and 3% in C with no difference between groups (I vs. C:1.03, 95%CI: 0.96-1.10; p = 1.000). Results concerning IGF-1 and IGFBP-3 also showed statistically significant dynamics over time with no difference between groups. No adverse events were reported. CONCLUSIONS: The home-based exercise program in our trial did not have any effect on IGF-1, or IGFBP-3. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov with identifier NCT02299596. This work was funded externally.

Roux Limb Motility in Gastric Bypass Patients with Chronic Abdominal Pain-Is There an Association to Prescribed Opioids?

BACKGROUND/AIM: A number of patients continue to suffer from chronic abdominal pain of unknown origin, which may also lead to a prolonged use of opioid analgesics. Symptoms of abdominal pain, nausea and vomiting in this patient group resemble the characteristics of the Roux stasis Syndrome. The aim was to elucidate relationships between chronic abdominal pain, Roux limb motor activity and opioid analgesics. METHODS: Roux limb high-resolution manometry and ratings of abdominal pain and quality of life were analysed in 15 gastric bypass patients reporting abdominal pain of unknown origin. Effect of acute opiate administration (morphine i.v.) on fasting Roux limb motor activity was assessed in asymptomatic and morphine-naïve gastric bypass patients (n = 9) and compared with an untreated control group (n = 11). RESULTS: In the symptomatic patient group, we found disturbed Roux limb motor patterns in 10 out of 15 examinations, but no signs of Roux stasis syndrome. A high prevalence of prescribed opioid analgesics as well as a high number of reoperations in this group. The worst quality of life and the highest number of pain-killing medications were observed among the patients with distal pacemaker activity in Roux limb. In the morphine-naïve and asymptomatic patients, morphine increased the muscular tone in the Roux limb during phase III-like motor activity. A majority of the RYGBP patients with chronic abdominal pain had a disturbed Roux limb fasting motility, and there was a high prevalence of prescribed opioid analgesics. In opiate-naïve RYGBP patients, acute morphine intravenously increased the muscular tone of the Roux limb.

Does intraperitoneal ropivacaine reduce postoperative inflammation? A prospective, double-blind, placebo-controlled pilot study.

BACKGROUND: Postoperative inflammation is a common consequence of surgery and the ensuing stress response. Local anesthetics have anti-inflammatory properties. The primary aim of this study was to evaluate if LA administrated intraperitoneally perioperatively might inhibit expression of inflammatory cytokines. METHODS: This was a, randomized, double blind, placebo-controlled study (ClinicalTrial.gov reg no: NCT02256228) in patients undergoing surgery for ovarian cancer. Patients were randomized to receive: intraperitoneal ropivacaine (Group IPLA) or saline (Group P) perioperatively. Except for study drug, patients were treated similarly. At the end of surgery, a multi-port catheter was inserted intraperitoneally, and ropivacaine 2 mg/mL or 0.9% saline, 10 mL was injected intermittently every other hour during 72 hours postoperatively. Systemic expression of cytokines and plasma ropivacaine were determined before and 6, 24, and 48 hours after surgery. Stress response was measured by serum glucose, cortisol, and insulin. RESULTS: Forty patients were recruited, 20 in each group. There was no statistical significant difference in systemic cytokine between the groups at any time point. Serum cortisol was significantly lower in the IPLA group at 6 hours, median 103 nmol/L (IQR 53-250) compared to placebo, median 440 nmol/L (IQR 115-885), P = 0.023. Serum glucose and insulin were similar between the groups. Total and free serum concentrations of ropivacaine were well below toxic concentrations. CONCLUSION: In this small study, perioperative intraperitoneal ropivacaine did not reduce the systemic inflammatory response associated with major abdominal surgery. Total and free ropivacaine concentrations were below known toxic concentrations in humans.

The effect of pre- and post-operative physical activity on recovery after colorectal cancer surgery (PHYSSURG-C): study protocol for a randomised controlled trial.

BACKGROUND: Surgery for colorectal cancer is associated with a high risk of post-operative adverse events, re-operations and a prolonged post-operative recovery. Previously, the effect of prehabilitation (pre-operative physical activity) has been studied for different types of surgery, including colorectal surgery. However, the trials on colorectal surgery have been of limited methodological quality and size. The aim of this trial is to compare the effect of a combined pre- and post-operative intervention of moderate aerobic physical activity and inspiratory muscle training (IMT) with standard care on post-operative recovery after surgery for colorectal cancer. METHODS/DESIGN: We are conducting a randomised, controlled, parallel-group, open-label, multi-centre trial with physical recovery within 4 weeks after cancer surgery as the primary endpoint. Some 640 patients planned for surgery for colorectal cancer will be enrolled. The intervention consists of pre- and post-operative physical activity with increased daily aerobic activity of moderate intensity as well as IMT. In the control group, patients will be advised to continue their normal daily exercise routine. The primary outcome is patient-reported physical recovery 4 weeks post-operatively. Secondary outcomes are length of sick leave, complication rate and severity, length of hospital stay, re-admittances, re-operations, post-operative mental recovery, quality of life and mortality, as well as changes in insulin-like growth factor 1 and insulin-like growth factor-binding protein 3, perception of pain and a health economic analysis. DISCUSSION: An increase in moderate-intensity aerobic physical activity is a safe, cheap and feasible intervention that would be possible to implement in standard care for patients with colorectal cancer. If shown to be effective, this lifestyle intervention could be a clinical parallel to pre-operative smoke cessation that has already been implemented with good clinical results. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02299596 . Registered on 17 November 2014.

Barrier pressure of the oesophagogastric junction during propofol induction with and without alfentanil: a double-blind, randomised, crossover study in volunteers.

CONTEXT: Practice varies regarding the use of opioids during rapid sequence induction. Controversy exists as to whether opioids may increase the risk of pulmonary aspiration by decreasing the barrier pressure (lower oesophageal sphincter-intragastric pressure). OBJECTIVES: To evaluate the effects of adding alfentanil during anaesthesia induction with propofol with respect to the barrier pressure in the oesophagogastric junction. PARTICIPANTS AND SETTING: Seventeen healthy volunteers (11 men and six women) participated in a double-blind, randomised, crossover trial at the University Hospital in Orebro, Sweden. INTERVENTIONS AND OUTCOME MEASURES: The volunteers were anaesthetised on two different occasions, randomly assigned to receive either alfentanil 20 µg kg(-1) or an equivalent amount of isotonic saline, administered intravenously, 1 min before induction with propofol 2 mg kg(-1). One minute after propofol administration, a cricoid pressure of 30 N was applied. The primary outcome was the difference in the change in barrier pressure between the alfentanil and the placebo occasion 1 min after propofol administration. The secondary outcomes were differences in the changes in barrier pressure 1 min after alfentanil or placebo administration and during ongoing cricoid pressure application. RESULTS: There were no statistically significant differences in barrier pressure, at any time point, between anaesthesia induction with alfentanil and propofol compared with induction with placebo and propofol. The barrier pressure never decreased to less than 2.4 mmHg in any volunteer. CONCLUSION: Our study showed no increased risk regarding the integrity of the gastro-oesophageal junction when alfentanil is added during an induction with propofol in volunteers. This supports the practice of adding opioids as adjuvants during rapid sequence induction.

Effects of propofol on oesophageal sphincters: a study on young and elderly volunteers using high-resolution solid-state manometry.

BACKGROUND AND OBJECTIVE: The oesophageal sphincters play an important role in protecting the airway. During manometric studies, administration of an anxiolytic agent is often required to make insertion of the catheter acceptable for the patient. The anxiolytic should not affect the results of the measurements. This study evaluates the effects of two different doses of propofol on the pressures in the oesophageal sphincters. The effect of increased abdominal pressure was also studied. METHODS: Twenty healthy volunteers, 10 young (mean age 25 years) and 10 elderly (mean age 71 years), were recruited. The effects of a low dose of propofol [0.3 mg kg(-1) intravenously (i.v.)] and a high dose of propofol (young group 0.9 mg kg(-1) i.v. and elderly group 0.6 mg kg(-1) i.v.) were studied with and without external abdominal pressure. RESULTS: There were no statistically significant changes in lower oesophageal sphincter (LOS) pressure after the low dose of propofol. After the high dose, there was an increase in LOS pressure, which was statistically significant in the young group (P < 0.05). The upper oesophageal sphincter (UOS) pressure decreased after both doses of propofol (P < 0.01 for the higher dose and P < 0.05 for the lower dose). CONCLUSION: A low dose of propofol (0.3 mg kg(-1) i.v.) leaves the LOS unaffected in young and elderly volunteers and can be used safely as an anxiolytic agent during studies of the LOS without influencing the results. However, the UOS is more sensitive to the effects of propofol and we do not recommend the use of propofol as an anxiolytic agent during manometric studies of the UOS.

High-resolution solid-state manometry of the upper and lower esophageal sphincters during anesthesia induction: a comparison between obese and non-obese patients.

BACKGROUND: The prevalence of obesity has increased dramatically in recent decades. The gastrointestinal changes associated with obesity have clinical significance for the anesthesiologist in the perioperative period. The lower esophageal sphincter and the upper esophageal sphincter play a central role in preventing regurgitation and aspiration. The effects of increased intra-abdominal pressure during anesthesia on the lower esophageal sphincter and the upper esophageal sphincter in obese patients are unknown. In the present study we evaluated, with high-resolution solid-state manometry, the upper esophageal sphincter, lower esophageal sphincter, and barrier pressure (BrP) (lower esophageal pressure--gastric pressure) in obese patients during anesthesia induction and compared them with pressures in non-obese patients. METHODS: We studied 28 patients, ages 18 to 72 years, 14 with a body mass index > or = 35 kg/m(2), who were undergoing laparoscopic gastric bypass, and 14 with a body mass index < or = 30 kg/m(2), who were undergoing laparoscopic cholecystectomy, using high-resolution solid-state manometry. RESULTS: Upper esophageal sphincter pressure decreased during anesthesia induction in both groups. Lower esophageal sphincter pressure decreased in both groups during anesthesia induction, and it was significantly lower in obese patients than in non-obese patients. The BrP decreased in both groups and was significantly lower in the obese group than in the non-obese group. The BrP remained positive at all times in both groups. CONCLUSION: Lower esophageal sphincter and BrPs decreased in both obese and non-obese patients during anesthesia induction, but were significantly lower in obese patients. Although the BrP was significantly lower, it remained positive in all patients.

A randomized simultaneous comparison of acceleromyography with a peripheral nerve stimulator for assessing reversal of rocuronium-induced neuromuscular blockade with sugammadex.

BACKGROUND AND OBJECTIVE: We investigated the relationship between acceleromyography and a peripheral nerve stimulator for measuring reversal in patients administered sugammadex following rocuronium. METHODS: In this randomized, active and within-participant controlled study, patients received rocuronium 0.6 mg kg for intubation with 0.15 mg kg maintenance doses as required. Single-dose sugammadex 4.0 or 1.0 mg kg was given 15 min after the last rocuronium dose. Neuromuscular monitoring was performed simultaneously: acceleromyography on one forearm and a peripheral nerve stimulator on the other. The peripheral nerve stimulator assessor was blinded to acceleromyography results. The primary efficacy end point was the difference between time from start of sugammadex 4.0 mg kg administration to recovery of the train-of-four ratio to 0.9 (acceleromyography) and time to reappearance of the fourth twitch (T4) (peripheral nerve stimulator). RESULTS: Sixty-one patients received sugammadex 4.0 mg kg. With acceleromyography, mean (SD) recovery time to a train-of-four ratio of at least 0.9 was 1.5 (0.7) min. With both the peripheral nerve stimulator and acceleromyography, mean (SD) time to T4 reappearance was 0.8 (0.3) min. Mean (95% confidence interval) difference between time to T4 reappearance (peripheral nerve stimulator) and recovery to a train-of-four ratio of at least 0.9 (acceleromyography) was 0.8 (0.6-0.9) min. CONCLUSION: T4 is detected at similar times when measured by a peripheral nerve stimulator or acceleromyography following sugammadex 4.0 mg kg administration 15 min after rocuronium. The mean interval between T4 reappearance (peripheral nerve stimulator) and recovery to a train-of-four ratio of at least 0.9 (acceleromyography) was 0.8 min. These findings provide guidance for evaluating the reversal effect of sugammadex in clinical situations.

Effects of remifentanil on gastric tone.

OBJECTIVES: Opioids are well known for impairing gastric motility. The mechanism is far from clear and there is wide interindividual variability. The purpose of this study was to evaluate the effect of remifentanil on proximal gastric tone. MATERIALS AND METHODS: Healthy volunteers were studied on two occasions and proximal gastric tone was measured by a gastric barostat. On the first occasion (n=8), glucagon 1 mg IV was given as a reference for a maximal relaxation of the stomach. On the second occasion (n=9), remifentanil was given in incremental doses (0.1, 0.2 and 0.3 microg/kg/min) for 15 min each, followed by a washout period of 30 min. Thereafter, remifentanil was readministered, and 10 min later glucagon 1 mg was given. Mean intragastric bag volumes were calculated for each 5-min interval. RESULTS: Glucagon decreased gastric tone in all subjects. Remifentanil had a marked effect on gastric tone; we found two distinct patterns of reactions with both increases and decreases in gastric tone and, during the remifentanil infusion, glucagon did not affect gastric tone. CONCLUSIONS: Remifentanil induced changes in gastric tone with both increases and decreases. The effect of remifentanil on gastric tone is probably dependent on the current state of the systems involved.