Perioperative Pain Management in Bariatric Anesthesia.

Weight loss (bariatric) surgery is the most commonly performed elective surgical procedure in patients with morbid obesity. In this review, we provide an evidence-based update on perioperative pain management in bariatric anesthesia. We mention some newer preoperative aspects-medical optimization, physical preparation, patient education, and psychosocial factors-that can all improve pain management. In the intraoperative period, with bariatric surgery being almost universally performed laparoscopically, we emphasize the use of non-opioid adjuvant infusions (ketamine, lidocaine, and dexmedetomidine) and suggest some novel regional anesthesia techniques to reduce pain, opioid requirements, and side effects. We discuss some postoperative strategies that additionally focus on patient safety and identify patients at risk of persistent pain and opioid use after bariatric surgery. This review suggests that the use of a structured, step-wise, severity-based, opioid-sparing multimodal analgesic protocol within an enhanced recovery after surgery (ERAS) framework can improve postoperative pain management. Overall, by incorporating all these aspects throughout the perioperative journey ensures improved patient safety and outcomes from pain management in bariatric anesthesia.

Effect of intraperitoneal local anesthesia on enhanced recovery outcomes after bariatric surgery: a randomized controlled pilot study.

BACKGROUND: Patients with extreme obesity are at high risk for adverse perioperative events, especially when opioid-centric analgesic protocols are used, and perioperative pain management interventions in bariatric surgery could improve safety, outcomes and satisfaction. We aimed to evaluate the impact of intraperitoneal local anesthesia (IPLA) on enhanced recovery after bariatric surgery (ERABS) outcomes. METHODS: We conducted a prospective double-blind randomized controlled pilot study in adherence to an a priori peer-reviewed protocol. Patients undergoing laparoscopic Roux-en-Y gastric bypass surgery (LRYGB) with an established ERABS protocol between July 2014 and February 2015 were randomly allocated to receive either IPLA with 0.2% ropivacaine (intervention group) or normal saline (control group). We measured pain scores, analgesic consumption and adverse effects. Functional prehabilitation outcomes, including peak expiratory flow (PEF) and the Six Minute Walk Test (6MWT) and Quality of Recovery Survey-40 (QoR-40) scores, were assessed before surgery, and 1 day and 7 days postoperatively. RESULTS: One hundred patients were randomly allocated to the study groups, of whom 92 completed the study, 46 in each group. There were no statistically significant differences between the 2 groups in baseline characteristics or any primary or secondary outcomes. Pain scores and analgesic consumption were low in both groups. There were no adverse events. Significant declines in PEF and 6MWT and QoR-40 scores were noted on postoperative day 1 in both groups; the values returned to baseline on postoperative day 7 in both groups. CONCLUSION: Intraperitoneal local anesthesia with ropivacaine did not reduce postoperative pain or analgesic consumption when administered intraoperatively to patients undergoing LRYGB. Standardization of the ERABS protocol benefited patients, with functional prehabilitation outcomes returning to baseline postoperatively. Trial registration: ClinicalTrials.gov no. NCT02154763.

Intravenous Lidocaine for Acute Pain: A Single-Institution Retrospective Study.

BACKGROUND: In the perioperative period, intravenous lidocaine has been used as an opioid-sparing systemic analgesic with additional anti-inflammatory and anti-hyperalgesic properties. OBJECTIVE: The aim of this retrospective study was to review the utilization, efficacy, and safety of intravenous lidocaine on our Acute Pain Service (APS) and identify surgical and patient populations where this intervention was found to be useful. PATIENTS AND METHODS: This retrospective study was designed to assess acute pain management in patients who received an intravenous lidocaine infusion between February 2013 and December 2017. Data collected included demographics, surgery type, infusion duration, pain scores, analgesic consumption, and adverse effects. Pain scores included rest and active pain scores and were analyzed by surgical model and subgroups. Clinically important differences (CIDs) in pain were determined by changes in pain score difference of ≥ 2 (11-point scale) or ≥ 30% reduction in pain intensity. A patient was considered to have a true CID if a CID was observed with rest and/or active pain scores at both first to second (4-24 h) and first to final time point (4 h to infusion end) comparisons. RESULTS: In total, 544 patients received intravenous lidocaine during this period, and 394 were included in the final analysis. The average (± standard deviation) duration of infusion was 68.60 ± 49.52 h. Surgical specialties included gastrointestinal surgery (41%), orthopedics (28%), neurosurgery (15%), vascular surgery (10%), and others (6%). Overall, 56.1% of the study population experienced a CID, with reduced pain scores at rest and/or with activity. CIDs were also observed in patients with chronic pain (53.5%) and when intravenous lidocaine was used as a rescue technique (69.6%). Within the rescue cohort, opioid-dependent and opioid-naïve patients experienced 23.0% and 45.6% reductions, respectively, in their 8-h intravenous opioid consumption. In total, 37 patients in the study experienced transient signs of mild local anesthetic toxicity, which resolved with infusion titration (conservative) management. One serious adverse event required intervention, and the patient was successfully resuscitated. CONCLUSIONS: This retrospective study at a single institution with an APS policy for intravenous lidocaine in the postoperative period identifies benefits of intravenous lidocaine in certain surgical and patient populations. The findings need to be confirmed with further research.

Randomised, double-blinded, placebo-controlled trial to investigate the role of laparoscopic transversus abdominis plane block in gastric bypass surgery: a study protocol.

INTRODUCTION: Evaluating the efficacy of a laparoscopically guided, surgical transversus abdominis plane (TAP) and rectus sheath (RS) block in reducing analgesic consumption while improving functional outcomes in patients undergoing laparoscopic bariatric surgery. METHODS: 150 patients Living with obesity undergoing elective laparoscopic Roux-En-Y gastric bypass for obesity will be recruited to this double-blinded, placebo-controlled randomised controlled trial from a Bariatric Centre of Excellence over a period of 6 months. Patients will be electronically randomised on a 1:1 basis to either an intervention or placebo group. Those on the intervention arm will receive a total of 60 mL 0.25% ropivacaine, divided into four injections: two for TAP and two for RS block under laparoscopic visualisation. The placebo arm will receive normal saline in the same manner. A standardised surgical and anaesthetic protocol will be followed, with care in adherence to the Enhanced Recovery after Bariatric Surgery guidelines. ANALYSIS: Demographic information and relevant medical history will be collected from the 150 patients enrolled in the study. Our primary efficacy endpoint is cumulative postoperative narcotic use. Secondary outcomes are peak expiratory flow, postoperative pain score and the 6 min walk test. Quality of recovery (QoR) will be assessed using a validated questionnaire (QoR-40). Statistical analysis will be conducted to assess differences within and between the two groups. The repeated measures will be analysed by a mixed modelling approach and results reported through publication. ETHICS AND DISSEMINATION: Ethics approval was obtained (20170749-01H) through our institutional research ethics board (Ottawa Health Science Network Research Ethics Board) and the study results, regardless of the outcome, will be reported in a manuscript submitted for a medical/surgical journal. TRIAL REGISTRATION NUMBER: Pre-results NCT03367728.

Perioperative Pain Management in Morbid Obesity.

Morbid obesity (MO) is becoming increasingly prevalent worldwide and is associated with both altered physiology and increased co-morbidities. Together, these can render the perioperative pain management in patients with MO particularly challenging. With the higher incidence of sleep-disordered breathing in this patient population, traditional opioid-centric pain management can often result in opioid-induced ventilatory impairment and increased morbidity and/or mortality. Multimodal analgesia strategies based on a step-wise, severity-based, opioid-sparing approach can improve patient safety and outcomes. These protocols should be standardized and implemented in the perioperative care of patients with MO. Further advancements in acute pain management have sought to identify and treat nociceptive and pro-nociceptive components (hyperalgesia, etc.) with both pharmacologic and non-pharmacologic measures. In addition to standardizing postoperative pain management, irrespective of the anesthetic and analgesic regimen used, some patients with MO will need extended monitoring for potential respiratory adverse events. In this review, we briefly describe the obesity-associated changes in physiology and their impact on the pharmacology of pain, and provide an evidence-based clinical update on the perioperative pain management in MO. We discuss the role of opioid-sparing pharmacological adjuvants and implementation of standardized protocols, and highlight future areas of research in perioperative pain management in this patient population.

Perioperative Pain and Addiction Interdisciplinary Network (PAIN) clinical practice advisory for perioperative management of buprenorphine: results of a modified Delphi process.

Until recently, the belief that adequate pain management was not achievable while patients remained on buprenorphine was the impetus for the perioperative discontinuation of buprenorphine. We aimed to use an expert consensus Delphi-based survey technique to 1) specify the need for perioperative guidelines in this context and 2) offer a set of recommendations for the perioperative management of these patients. The major recommendation of this practice advisory is to continue buprenorphine therapy in the perioperative period. It is rarely appropriate to reduce the buprenorphine dose irrespective of indication or formulation. If analgesia is inadequate after optimisation of adjunct analgesic therapies, we recommend initiating a full mu agonist while continuing buprenorphine at some dose. The panel believes that before operation, physicians must distinguish between buprenorphine use for chronic pain (weaning/conversion from long-term high-dose opioids) and opioid use disorder (OUD) as the primary indication for buprenorphine therapy. Patients should ideally be discharged on buprenorphine, although not necessarily at their preoperative dose. Depending on analgesic requirements, they may be discharged on a full mu agonist. Overall, long-term buprenorphine treatment retention and harm reduction must be considered during the perioperative period when OUD is a primary diagnosis. The authors recognise that inter-patient variability will require some individualisation of clinical practice advisories. Clinical practice advisories are largely based on lower classes of evidence (level 4, level 5). Further research is required in order to implement meaningful changes in practitioner behaviour for this patient group.

"CAPS" Cardiac Acute Pain Services-A Nationwide Survey From Canada.

OBJECTIVES: Acute Pain Services (APS) are well-established worldwide; however, their availability and use in cardiac surgery units are less widespread and, even where present, may be provided less consistently. The authors undertook this survey to assess the current organization of Cardiac Acute Pain Services (CAPS) in Canada. DESIGN: This was a prospectively administered survey. SETTING: This study included all centers in Canada that conducted adult cardiac surgery. PARTICIPANTS: The participants were anesthesiologists. INTERVENTION: A 20-item questionnaire covered the demographics, functioning and APS structure. RESULTS: The authors achieved a response rate of 100% with completed questionnaires from all 31 centers. Ten centers (32.3%) stated that they had a dedicated CAPS, 9 centers (29%) stated that they did not have an APS, and 12 centers (38.7%) had APS but no CAPS. At the time of the survey for the 10 centers with CAPS, 3 of the CAPS had a physician-run model, 4 had a combined physician and nurse service, and 1 used a combination of protocols, intensivists, and nurse practitioners. Nine centers had an anesthesiologist assigned to daily acute pain rounds. Only in 2 of 10 centers with CAPS were more than 50% of their cardiac surgery patients receiving care. In general, postoperative pain management was a protocol-driven activity. CONCLUSIONS: CAPS are varied in both structure and functioning. Further work is required both at the institutional and the national levels to improve the postoperative care and the pain-related outcomes of patients undergoing cardiac surgery.

Acute pain management in morbid obesity - an evidence based clinical update.

Increasing numbers of patients with morbid obesity are presenting for surgery and their acute pain management requires an evidence-based clinical update. The objective of this study was to complete a literature review for acute pain management in morbid obesity and provide an evidence-based clinical update with recommendations. Using standardized search terms, in March 2015, we completed a literature search to determine evidence for different acute pain pharmacological modalities in morbid obesity. For each modality the highest level of evidence was ascertained and recommendations for each pharmacological modality are presented. Though overall evidence is limited to few well conducted clinical trials, mostly related to weight loss surgery, multimodal analgesia with step-wise, severity-based, opioid-sparing approach appears to improve acute pain management in morbid obesity. The perioperative use of non-opioid adjuvants appears to offer further improvements in patient safety and outcomes. Further research into standardization of pain assessments and implementation of acute pain management protocols is required.

Perioperative use of pregabalin for acute pain-a systematic review and meta-analysis.

Evidence supporting postoperative pain management using pregabalin as an adjunct intervention across various surgical pain models is lacking. The objective of this systematic review was to evaluate "model-specific" comparative effectiveness and harms of pregabalin following a previously published systematic review protocol. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched from inception through August 2013. Data were screened and single extraction with independent verification and dual risk of bias assessment was performed. Quality of evidence (QoE) was rated using the GRADE approach. Primary outcomes were pain relief at rest and on movement and reduction in postoperative analgesic consumption. A total of 1423 records were screened, and 43 studies were included. Perioperative pregabalin resulted in: 16% (95% confidence interval [CI], 9%-21%) reduction in analgesic consumption (moderate QoE, 24 trials) and a small reduction in the magnitude of pain in surgeries associated with pronociceptive pain. Per 1000 patients, 10 more will experience blurred vision (95% CI, 5-20 more; moderate QoE, 17 trials) and 41 more sedation (95% CI, 13-77 more, 17 trials). To prevent 1 case of perioperative nausea and vomiting, the number needed to treat is 11 (95% CI: 7-28, 25 trials). Inadequate evidence addressed outcomes of enhanced recovery and serious harms. Pregabalin analgesic effectiveness is largely restricted to surgical procedures associated with pronociceptive mechanisms. The clinical significance of observed pregabalin benefits must be weighed against the uncertainties about serious harms and enhanced recovery to inform the careful selection of surgical patients. Recommendations for future research are proposed.

Assessing the feasibility of a randomised, double-blinded, placebo-controlled trial to investigate the role of intraperitoneal ropivacaine in gastric bypass surgery: a protocol.

INTRODUCTION: Postoperative pain control remains a major challenge for surgical procedures, including laparoscopic gastric bypass. Pain management is particularly relevant in obese patients who experience a higher number of cardiovascular and pulmonary events. Effective pain management may reduce their risk of serious postoperative complication, such as deep vein thrombosis and pulmonary emboli. The objective of this study is to evaluate the efficacy of intraperitoneal local anaesthetic, ropivacaine, to reduce postoperative pain in patients undergoing laparoscopic Roux-en-Y gastric bypass. METHODS AND ANALYSIS: A randomised controlled trial will be conducted to compare intraperitoneal ropivacaine (intervention) versus normal saline (placebo) in 120 adult patients undergoing bariatric bypass surgery. Ropivacaine will be infused over the oesophageal hiatus and throughout the abdomen. Patients in the control arm will undergo the same treatment with normal saline. The primary end point will be postoperative pain at 1, 2 and 4 h postoperatively. Pain measurements will then occur every 4 h for 24 h and every 8 h until discharge. Secondary end points will include opioid use, peak expiratory flow, 6 min walk distance and quality of life assessed in the immediate postoperative period. Intention-to-treat analysis will be used and repeated measures will be analysed using mixed modelling approach. Post-hoc pairwise comparison of the treatment groups at different time points will be carried out using multiple comparisons with adjustment to the type 1 error. Results of the study will inform the feasibility of recruitment and inform sample size of a larger definitive randomised trial to evaluate the effectiveness of intraperitoneal ropivacaine. ETHICS AND DISSEMINATION: This study has been approved by the Ottawa Health Science Network Research Ethics Board and Health Canada in April 2014. The findings of the study will be disseminated through national and international conferences and peer-reviewed journals. TRIAL REGISTRATION NUMBER: Clinicaltrial.gov NCT02154763.

Airway management in cervical spine ankylosing spondylitis: Between a rock and a hard place.

We report the perioperative course of a patient with long standing ankylosing spondylitis with severe dysphagia due to large anterior cervical syndesmophytes at the level of the epiglottis. He was scheduled to undergo anterior cervical decompression and the surgical approach possibly precluded an elective pre-operative tracheostomy. We performed a modified awake fibreoptic nasal intubation through a split nasopharyngeal airway while adequate oxygenation was ensured through a modified nasal trumpet inserted in the other nares. We discuss the role of nasal intubations and the use of both the modified nasopharyngeal airways we used to facilitate tracheal intubation. This modified nasal fibreoptic intubation technique could find the application in other patients with cervical spine abnormalities and in other anticipated difficult airways.

A protocol for a systematic review for perioperative pregabalin use.

BACKGROUND: Perioperative pain management has recently been revolutionized with the recognition of novel mechanisms and introduction of newer drugs. Many randomized trials have studied the use of the gabapentinoid anti-epileptic, pregabalin, in acute pain. Published systematic reviews suggest that using pregabalin for perioperative pain management may decrease analgesic requirements and pain scores, at the expense of troublesome side effects. A major limitation of the extant reviews is the lack of rigorous investigation of clinical characteristics that would maximize the benefit harms ratio in favor of surgical patients. We posit that effects of pregabalin for perioperative pain management vary by the type of surgical pain model and propose this systematic review protocol to update previous systematic reviews and investigate the heterogeneity in findings across subgroups of surgical pain models. METHODS/DESIGN: Using a peer-reviewed search strategy, we will search key databases for clinical trials on perioperative pregabalin use in adults. The electronic searches will be supplemented by scanning the reference lists of included studies. No limits of language, country or year will be imposed. Outcomes will include pain; use of co-analgesia, particularly opioids; enhanced recovery; and drug-related harms. We will focus on the identification of surgical models and patient characteristics that have shown benefit and adverse effects from pregabalin.Two clinical experts will independently screen the studies for inclusion using eligibility criteria established a priori. Data extracted by the reviewers will then be verified. Publication bias will be assessed, as will risk of bias using the Cochrane Risk of Bias tool. Meta-analysis and meta-regression are planned if the studies are deemed statistically, methodologically and clinically homogenous. Evidence will be graded for its strength for a select number of outcomes. DISCUSSION: We will explore the findings of perioperative clinical trials studying the use of pregabalin for acute pain. We will comment on the implications of the findings and provide further direction for the appropriate use of pregabalin in acute pain. This protocol will attempt to bridge the growing gap between clinical experience and emerging evidence, and has the potential to aid future guideline development in the perioperative use of pregabalin. TRIAL REGISTRATION: PROSPERO registration number CRD42012002078.