What is the best approach to manage severe abdominal pain in a patient with a history of gastric bypass surgery, addiction, and current use of buprenorphine, who also presents with tachycardia and slight hypotension?

Management of Severe Abdominal Pain in a Post-Gastric Bypass Patient on Buprenorphine

Continue the patient's buprenorphine at their maintenance dose and aggressively treat the acute pain with full mu-agonist opioids (fentanyl, hydromorphone, or morphine) at higher-than-typical doses and shorter intervals, while simultaneously pursuing urgent diagnostic evaluation for surgical complications, particularly internal herniation. 1

Immediate Clinical Priorities

Hemodynamic Stabilization and Surgical Evaluation

• The tachycardia and hypotension demand immediate assessment for surgical emergencies, particularly internal herniation, which is the most common serious complication causing severe abdominal pain years after gastric bypass. 2, 3
• Internal herniation occurred in 13% of patients with chronic post-RYGB abdominal pain in one diagnostic algorithm study, making it a critical consideration. 3
• Initiate IV fluid resuscitation while obtaining urgent CT imaging with oral and IV contrast to evaluate for internal hernia, bowel obstruction, or other surgical pathology. 2, 3

Pain Management Strategy

Continue Buprenorphine Maintenance

• Do not discontinue or reduce the patient's buprenorphine dose, as this risks destabilizing their opioid use disorder and provides no benefit for acute pain management. 1
• The British Journal of Anaesthesia guidelines emphasize that discontinuation increases relapse risk and can exacerbate underlying addiction without improving pain control. 1
• Verify the current buprenorphine dose with the patient's prescribing physician and continue it at the scheduled maintenance dose. 1

Initiate Full Mu-Agonist Opioids

• After starting multimodal adjuncts (see below), initiate a full mu-agonist such as fentanyl, hydromorphone, or morphine for acute pain control. 1
• Expect to use substantially higher doses at shorter intervals than in opioid-naïve patients due to buprenorphine's high mu-receptor affinity and the patient's opioid tolerance. 1
• Use scheduled continuous dosing rather than as-needed orders to maintain adequate analgesia. 1
• Avoid mixed agonist-antagonist opioids (pentazocine, nalbuphine, butorphanol) as these may precipitate acute withdrawal. 1

Multimodal Analgesia

• Initiate adjunctive analgesics immediately, including IV acetaminophen, ketorolac (if not contraindicated by hemodynamic instability), and consider IV ketamine or lidocaine infusion. 1, 4
• These adjuncts can reduce total opioid requirements while providing superior overall analgesia. 1, 4

Critical Diagnostic Considerations

Post-Gastric Bypass Complications

The differential diagnosis for severe abdominal pain years after gastric bypass includes:

• Internal herniation (most urgent surgical emergency). 2, 3
• Bowel obstruction from adhesions. 2
• Marginal ulceration at the gastrojejunal anastomosis. 3
• Gallstones (present in 11% of chronic pain cases in one series). 3
• Dumping syndrome. 3
• Food intolerance or stricture. 3

Avoiding Diagnostic Pitfalls

• Do not attribute all symptoms to drug-seeking behavior simply because the patient has an addiction history—this is "pseudoaddiction" where inadequate pain control drives medication-seeking behaviors. 1
• In one case series, multiple patients underwent unnecessary repeat procedures because their legitimate surgical complications were misattributed to narcotic-seeking behavior or withdrawal. 5, 6
• The diagnosis of internal hernia can be challenging and may require laparoscopy even when imaging is equivocal, particularly given the hemodynamic instability. 2, 3

Monitoring and Safety

Enhanced Surveillance

• Have naloxone immediately available at bedside given the combination of buprenorphine and full mu-agonists. 1
• Monitor respiratory rate, oxygen saturation, and level of sedation every 1-2 hours initially. 1
• If buprenorphine dose reduction becomes necessary due to inadequate analgesia despite escalating opioid doses, implement additional monitoring for both pain control and withdrawal symptoms. 1

Communication with Addiction Treatment Provider

• Notify the patient's buprenorphine prescriber immediately regarding hospitalization, confirming the last maintenance dose and informing them of any additional opioids administered. 1
• This prevents misinterpretation of urine drug screens and maintains continuity of addiction care. 1

Disposition Planning

If Surgical Intervention Required

• For inpatients requiring surgery, one option is to temporarily convert from buprenorphine to methadone 20-40 mg daily for opioid dependence management, use short-acting opioids for surgical pain, then convert back to buprenorphine before discharge. 1
• However, the more contemporary approach is to continue buprenorphine throughout the perioperative period, which reduces relapse risk. 1

Reassurance and Non-Judgmental Approach

• Explicitly reassure the patient that their addiction history will not prevent adequate pain management. 1
• Discuss the pain management plan in a supportive, non-judgmental manner to reduce anxiety, which can worsen both pain perception and hemodynamic instability. 1

Transition of Care

• Before discharge, ensure coordination between surgery, pain management, and the patient's outpatient buprenorphine provider. 1
• Plan for appropriate opioid tapering as surgical pain resolves, with clear follow-up to prevent both undertreated pain and opioid misuse. 1

Common Pitfalls

• Stopping buprenorphine in the mistaken belief it will improve opioid analgesia—this destabilizes addiction treatment without benefit. 1
• Undertreating pain due to concerns about addiction—patients on buprenorphine maintenance require aggressive pain management with higher opioid doses. 1
• Delaying surgical evaluation while focusing solely on pain management—the hemodynamic instability suggests a surgical emergency. 2, 3
• Attributing legitimate surgical pain to drug-seeking behavior—post-gastric bypass patients can develop serious complications years after surgery. 5, 6, 3