Optimal Perioperative Pain Management for Gastric Bypass Surgery

Educational Objectives

The goal of this program is to improve perioperative pain management of patients undergoing gastric bypass surgery. After hearing and assimilating this program, the clinician will be better able to:

1. Identify the immediate challenges to improving the quality of bariatric surgical care.
2. List the preoperative, intraoperative, and postoperative components of Enhanced Recovery After Surgery (ERAS) protocols.
3. Cite differences between the 2016 and the 2021 Guidelines for Perioperative Care in Bariatric Surgery: ERAS Society Recommendations.

Summary

Enhanced Recovery After Surgery (ERAS) guidelines for bariatric surgery: updated in 2021; ERAS protocols are divided into preoperative, intraoperative, and postoperative recommendations

Preoperative Care

Counseling: compared with other patients, those undergoing bariatric surgery receive the most counseling (because of the 6- to 12-mo gap between the initial surgical consultation and surgery)

Prehabilitation: patients are placed on a very-low-calorie diet (improves insulin sensitivity or reduces insulin resistance in diabetics) and a regimen of exercise and strength training; one of the most significant benefits of losing 10% of body weight is a comparable reduction in liver size, which aids in visualization of the stomach during bariatric surgery

Preoperative fasting: evidence suggests that patients with morbid obesity do not have slower gastric emptying than other patients; therefore, according to guidelines from the American Society of Anesthesiologists, patients should be allowed clear fluids for up to 2 hr prior to surgery, and light meals up to 6 hr before surgery

Carbohydrate loading: patients are advised to consume 800 mL of a high-carbohydrate drink the night before surgery and 400 mL the morning of surgery (however, those with uncontrolled diabetes should refrain from the morning carbohydrate load)

Strength of recommendations: in the 2021 update, counseling is strongly recommended; indications for bariatric surgery should follow the national guidelines; although the recommendation for prehabilitation is weak, it is likely to be beneficial; the guidelines suggest discontinuation of smoking 4 wk before the procedure and avoidance of alcohol for 1 to 2 yr preoperatively (the latter is impractical for most surgical patients but possibly achievable in patients planning well in advance to have bariatric surgery); preoperative weight loss is strongly recommended; 8 mg of intravenous (IV) dexamethasone 90 min before induction of anesthesia is recommended (common practice in Europe); the recommendation for administration of ß-blockers is weak; preoperative fasting is strongly recommended, except in patients with diabetes or gastroparesis; carbohydrate loading has a weak recommendation

Intraoperative Care

Postoperative nausea and vomiting (PONV): as 90% of the readmissions after bariatric surgery are attributed to pain or PONV, planning for PONV prophylaxis is important

Perioperative fluid management: as bariatric surgeries last only 1 to 1.5 hr, patients do not receive huge volumes of fluids; the goal is to maintain a zero balance

Anesthetic protocols: no specific recommendations have been made for anesthetics (inhalational agents or total intravenous anesthesia are options); the strongest recommendation for anesthesiology is use of opioid-sparing medications for pain management

PONV prophylaxis: despite treatment, PONV occurs in ≈78% of women and 26% of men within the first 24 hr after surgery; ≈34% have severe PONV in the first 24 hr; ≈32% require rescue antiemetics; several studies show that risk for PONV is 82% with optimal prophylaxis (ie, matching the number of antiemetic agents administered to the Apfel Risk Score); 34% of patients have PONV after receiving “supra-optimal prophylaxis” (ie, a number antiemetic agents equal to the Apfel Risk Score plus 1); among patients who received triple prophylaxis, 43% required a rescue antiemetic agent in the first 24 hr

Speaker’s protocol: preoperative — scopolamine patch and oral aprepitant; intraoperative — dexamethasone and ondansetron, with low-dose propofol infusion as the anesthetic; postoperative — 3 rescue antiemetics are available

Fluid management: intraoperative fluids do not exceed 0.5 to 1 L in most patients; sitting-up position reduces fluid requirements; ERAS guidelines list maintaining a zero balance as a strong recommendation

Airway management: preoxygenate patients in a 25-degrees head-up position; the use of continuous positive airway pressure (CPAP) during preoxygenation (ie, closure of the adjustable pressure-limiting valve to ≥5 cm H₂O) is advised to open up the alveoli; for difficult airways, continue oxygenation during intubation (with, eg, nasal oxygen, high-flow nasal cannula); alternatively, the insertion of a nasal Ring-Adair-Elwyn (RAE) tube on the side of the mouth helps to passively oxygenate the high-risk patient

Ventilation: provide lung-protective ventilation; maintain tidal volumes at 6 to 8 mL of ideal body weight; minimize the increase in driving pressure; adjust the inspiratory-to-expiratory ratio (I:E; consider an I:E of 1:1, instead of 1:2, to increase the time for inspiration, especially in patients who cannot be oxygenated [eg, those undergoing robotic surgery]); use of recruitment maneuvers (administration of positive pressure [30-35 cm H₂O] for 10-30 sec) is recommended; as studies have shown that exceeding 30 sec may result in red blood cell microleaks, the speaker recommends frequent, 10-sec durations of positive pressure; positive end-expiratory pressure (PEEP) should be optimally adjusted (to 5-10 cm H₂O)

Neuromuscular blockade: has a weak recommendation; some studies have found that deep relaxation (train of four ratio of 0 and post-tetanic count of 1-2) may reduce peritoneal inflammation; however, patients require complete reversal after robotic surgery; use of sugammadex ensures full recovery; qualitative monitoring of neuromuscular blockade is recommended

BIS monitoring: allows minimization of the dose of anesthetic agent required for deep anesthesia

Surgical technique: laparoscopic procedures performed by senior surgeons are recommended; the American College of Surgery grants accreditation to Centers of Excellence for bariatric procedures based on the volume of procedures performed, as high volumes are associated with better surgical outcomes

Abdominal drains and nasogastric decompression: not recommended for bariatric surgery

Postoperative Care

Postoperative oxygenation: maximized by keeping the patient upright; supplemental oxygen can be given in small doses; patients should be able to take enteral nutrition within 2 to 4 hr of surgery; the sitting posture aids in restoring, eg, functional residual capacity

Continuous positive airway pressure: recommended for patients with severe sleep apnea or obesity hyperventilation syndrome (OHS; associated with high daytime carbon dioxide levels, high baseline bicarbonate levels, and low oxygen levels); extubation to a CPAP or bilevel positive airway pressure machine in the operating room is preferred for patients with OHS

Thromboprophylaxis: all patients should receive low-molecular-weight heparin to prevent postoperative thrombosis

Nutritional care: a “clear meal” is recommended within 2 hr of surgery; all patients should have access to a comprehensive nutrition and dietary assessment, with lifelong supplementation of vitamins and minerals; some patients experience acid reflux immediately after surgery; consider administering a proton pump inhibitor or H2 blocker intraoperatively

Other procedures: patients who have undergone bariatric surgery are at increased risk for gallstones; this condition can be treated surgically

Hospital stay: the length of hospital stay for bariatric surgery has shortened from 5 to 6 days to 1 to 2 days; Ardila-Gatas et al (2019) — compared bariatric surgery outcomes in patients who were discharged on postoperative day (POD) 2 vs POD1; patients discharged on POD1 had lower rates of morbidity, 30-day reintervention, and readmission, and better overall outcomes immediately after surgery and at 30 days; Jakob et al (2016) — showed that 98% of patients were able to be discharged home <24 hr after sleeve gastrectomy; complications included surgery-related bleeding and PONV in 0.6%; Wiggins et al (2020) — showed that bariatric surgery is beneficial to high-risk patients because it reduces all-cause mortality (including cardiovascular mortality); diabetes resolves within 24 hr of the procedure; Ahmed et al (2018) — performed a meta-analysis showing that length of stay was reduced by 1.5 days with use of ERAS recommendations (≥$10,000 in cost savings); adverse events, reinterventions, and readmissions were substantially reduced in patients treated according to ERAS protocols

Multimodal analgesia: small doses of postoperative opioids remain an option; intraoperative use of opioid-sparing agents is highly recommended; other analgesics (eg, acetaminophen, norepinephrine reuptake inhibitors [eg, tramadol], ketamine, local anesthetics [regional anesthesia or α2 agonists, such as dexmedetomidine], and nonsteroidal anti-inflammatory agents) have been effectively used

Speaker’s analgesic protocol: includes preoperative use of 1 g acetaminophen (eg, Apra, Panadol, Tylenol), with 200 mg celecoxib (Celebrex) and 50 to 150 mg pregabalin, depending on the severity of pain anticipated; methocarbamol (a muscle relaxant) may be added; intraoperatively, small doses of narcotics may be used for induction; when avoidance of all opioids is desired, a bolus of dexmedetomidine (4-10 μg), in small increments, with 2 mg/kg of lidocaine and 0.2 mg/kg of ketamine may be used; this combination is effective for intubation and preserves hemodynamic stability; intraoperatively, ketamine infusion or multiple small doses of ketamine and dexmedetomidine may be used; this regimen is effective in patients with a transversus abdominis plane (TAP) block; patients who have received narcotics should not lie flat during the immediate postoperative period

Future goals for bariatric anesthesia: increase the role of regional anesthesia in pain relief; reduce (and eventually discontinue) use of opioids; use foundational analgesics (eg, acetaminophen, NSAIDs) and lidocaine; in patients with morbid obesity, a single, 1- to 2-g dose of magnesium (an N-methyl-D-aspartic acid antagonist) given after induction reduces the dose of neuromuscular blockade required; ketamine, dexmedetomidine, and TAP blocks minimize overall opioid requirements

Readings

Ahmed OS, Rogers AC, Bolger JC, et al. Meta-analysis of enhanced recovery protocols in bariatric surgery. J Gastrointest Surg. 2018;22(6):964-972. doi:10.1007/s11605-018-3709-x; Ardila-Gatas J, Sharma G, Lloyd SJ, et al. A nationwide safety analysis of discharge on the first postoperative day after bariatric surgery in selected patients. Obes Surg. 2019;29(1):15-22. doi:10.1007/s11695-018-3489-0; Buchholz V, Berkenstadt H, Goitein D, et al. Gastric emptying is not prolonged in obese patients. Surg Obes Relat Dis. 2013;9(5):714-717. doi:10.1016/j.soard.2012.03.008; Durrand JW, Batterham AM, Danjoux GR. Pre-habilitation. I: aggregation of marginal gains. Anaesthesia. 2014;69(5):403–406. doi: 10.1111/anae.12666; Jakob T, Cal P, Deluca L, et al. Shorter than 24-h hospital stay for sleeve gastrectomy is safe and feasible. Surg Endosc. 2016;30(12):5596-5600. doi:10.1007/s00464-016-4933-7; Małczak P, Pisarska M, Piotr M, et al. Enhanced recovery after bariatric surgery: Systematic review and meta-analysis. Obes Surg. 2017 Jan;27(1):226-235. doi: 10.1007/s11695-016-2438-z; Rausa E, et al. Rate of death and complications in laparoscopic and open Roux-en-Y gastric bypass. A meta-analysis and meta-regression analysis on 69,494 patients. Obes Surg. 2016;26(8):1956–1963. doi: 10.1007/s11695-016-2231-z; Sattler LN, Hing WA, Rathbone EN, Vertullo CJ. Which patient factors best predict discharge destination after primary total knee arthroplasty? The ARISE Trial. J Arthroplasty. 2020;35(10):2852-2857. doi:10.1016/j.arth.2020.05.056; Stenberg E, Dos Reis Falcão LF, O'Kane M, et al. Guidelines for perioperative care in bariatric surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations: A 2021 Update [published correction appears in World J Surg. 2022 Jan 29;:]. World J Surg. 2022;46(4):729-751. doi:10.1007/s00268-021-06394-9; Wiggins T, Guidozzi N, Welbourn R, et al. Association of bariatric surgery with all-cause mortality and incidence of obesity-related disease at a population level: a systematic review and meta-analysis. PLoS Med. 2020;17(7):e1003206. Published 2020 Jul 28. doi:10.1371/journal.pmed.1003206; Ziemann-Gimmel P, Schumann R, English W, et al. Preventing nausea and vomiting after bariatric surgery: is the Apfel Risk Prediction Score enough to guide prophylaxis?. Obes Surg. 2020;30(10):4138-4140. doi:10.1007/s11695-020-04682-2.

Disclosures

For this program, members of the faculty and planning committee reported nothing relevant to disclose.

Acknowledgements

Dr. Wadhwa was recorded at the 70th Annual Convention and Conclave of the American Osteopathic College of Anesthesiologists, held September 17-20, 2022, in Phoenix, AZ, and presented by the American Osteopathic College of Anesthesiologists. For information about upcoming CME activities from this presenter, please visit aocaonline.org. Audio Digest thanks the speakers and American Osteopathic College of Anesthesiologists for their cooperation in the production of this program.

CME/CE INFO

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The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 1.00 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

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Lecture ID:

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Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.