How to manage non-occlusive mesenteric inflammation (NOMI) in patients with a history of long-term opiate use?

Management of Non-Occlusive Mesenteric Inflammation (NOMI) in Patients with Long-Term Opioid Use

Long-term opioid use should be discontinued in patients with non-occlusive mesenteric inflammation as opioids are associated with poor outcomes, increased risk of serious infections, and higher mortality. 1

Understanding the Relationship Between Opioids and Mesenteric Inflammation

• Long-term opioid use can cause or exacerbate gastrointestinal dysmotility, which may contribute to non-occlusive mesenteric inflammation 1
• Opioids have both analgesic and anti-motility properties that can lead to severe constipation, bowel dysfunction, and in extreme cases, mimic features of chronic intestinal pseudo-obstruction (CIPO) 1
• Narcotic bowel syndrome, characterized by paradoxical worsening of abdominal pain despite continued or escalating doses of opioids, may develop in approximately 6% of chronic opioid users 1, 2
• Historical studies show an association between opioid prescription and development of toxic megacolon in fulminant colitis 1

Diagnostic Approach for NOMI in Opioid Users

• NOMI should be suspected in patients on opioids who present with abdominal pain or distension, particularly if they require vasopressor support or show evidence of multiorgan dysfunction 1
• CT angiography (CTA) is the preferred diagnostic modality, which may demonstrate bowel ischemia and free fluid despite patent mesenteric vessels 1
• Unexplained abdominal distension, gastrointestinal bleeding, or right-sided abdominal pain with passage of maroon or bright red blood in stool are highly suggestive of NOMI 1
• Rule out other causes of pain including stricturing disease, abscesses, uncontrolled inflammation, adhesions, and functional bowel disorders 1

Management Algorithm for NOMI in Opioid Users

Immediate Management:

1. Fluid Resuscitation and Stabilization

   • Begin immediate fluid resuscitation with crystalloids to enhance visceral perfusion 1
   • Correct electrolyte abnormalities and initiate nasogastric decompression 1
   • Use vasopressors with caution; dobutamine, low-dose dopamine, and milrinone have less impact on mesenteric blood flow 1

2. Opioid Management

   • Implement controlled opioid withdrawal under medical supervision 1
   • Consider peripherally acting μ-opioid receptor antagonists (PAMORAs) for opioid-induced constipation during the transition period 1
   • Avoid cyclizine and other anticholinergic medications that may worsen dysmotility 1

Long-term Management:

1. Pain Management Alternatives

   • Replace opioids with non-opioid analgesics 1
   • Consider neuromodulators (e.g., mirtazapine) to improve gut function 1
   • Implement psychological support and behavioral approaches for pain management 1

2. Nutritional Support

   • Prioritize oral or enteral nutrition over parenteral support when possible 1
   • Monitor nutritional status closely during the transition period 1
   • Reserve parenteral nutrition for cases of severe progressive life-threatening malnutrition 1

3. Multidisciplinary Approach

   • Involve pain specialists for alternative pain management strategies 1
   • Include psychological support to address potential opioid dependence 1
   • Regular monitoring for recurrence of mesenteric inflammation 1

Common Pitfalls and Caveats

• Failing to recognize narcotic bowel syndrome, which is often misdiagnosed as a functional gastrointestinal disorder 3, 2
• Continuing to escalate opioid doses when pain worsens, which paradoxically can exacerbate the condition 1, 2
• Overlooking the potential for opioid-induced hyperalgesia, where opioids actually increase pain sensitivity 2
• Not addressing psychological dependence on opioids during treatment 1
• Inadequate fluid resuscitation during the acute management of NOMI 1
• Assuming that all abdominal pain in IBD patients on opioids is due to disease activity rather than opioid-induced effects 4

Special Considerations

• Patients with inflammatory bowel disease (IBD) on opioids have higher risk of serious infections and mortality 1, 4
• Opioid-induced constipation can lead to severe complications including stercoral colitis and even pneumoperitoneum 5
• In patients with IBD, abdominal pain accounts for approximately 23% of opioid indications, with IBD-related complaints being more common among high-dose users 4
• The detoxification process requires close monitoring and may include medications such as methadone, lorazepam, clonidine, and duloxetine to manage withdrawal symptoms 3