Neostigmine infusion: new standard of care for acute colonic pseudo-obstruction?

Randomized controlled trial: neostigmine for intra-abdominal hypertension in acute pancreatitis

Background

Intra-abdominal hypertension (IAH) in acute pancreatitis (AP) is associated with deterioration in organ function. This trial aimed to assess the efficacy of neostigmine for IAH in patients with AP.

Methods

In this single-center, randomized trial, consenting patients with IAH within 2 weeks of AP onset received conventional treatment for 24 h. Patients with sustained intra-abdominal pressure (IAP) ≥ 12 mmHg were randomized to receive intramuscular neostigmine (1 mg every 12 h increased to every 8 h or every 6 h, depending on response) or continue conventional treatment for 7 days. The primary outcome was the percent change of IAP at 24 h after randomization.

Results

A total of 80 patients were recruited to neostigmine (n = 40) or conventional treatment (n = 40). There was no significant difference in baseline parameters. The rate of decrease in IAP was significantly faster in the neostigmine group compared to the conventional group by 24 h (median with 25th–75th percentile: −18.7% [− 28.4 to − 4.7%] vs. − 5.4% [− 18.0% to 0], P = 0.017). This effect was more pronounced in patients with baseline IAP ≥ 15 mmHg (P = 0.018). Per-protocol analysis confirmed these results (P = 0.03). Stool volume was consistently higher in the neostigmine group during the 7-day observational period (all P < 0.05). Other secondary outcomes were not significantly different between neostigmine and conventional treatment groups.

Conclusion

Neostigmine reduced IAP and promoted defecation in patients with AP and IAH. These results warrant a larger, placebo-controlled, double-blind phase III trial.

Trial registration Clinical Trial No: NCT02543658 (registered August /27, 2015).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03922-4.

Acute Colonic Pseudo-obstruction and Volvulus: Pathophysiology, Evaluation, and Treatment

Acute colonic pseudo-obstruction (ACPO) and volvulus are two disease processes that affect the colon causing abdominal distension and may necessitate operation intervention. ACPO may be associated with multiple comorbidities, infectious diseases, and cardiac dysfunction. It may be treated with conservative management including endoscopic decompression or neostigmine. If the distension is not addressed, high mortality may result if peritonitis develops. Volvulus most commonly occurs in the sigmoid colon or cecum. If left-sided, endoscopic decompression may resolve the obstruction if detorsion is successful, although sigmoid colectomy should be performed during the admission. If cecal volvulus is identified, right hemicolectomy should be performed.

Ogilvie's syndrome treated with an emergency laparotomy, right hemicolectomy and end ileostomy

Acute colonic pseudo-obstruction (ACPO), or Ogilvie's syndrome, is a rare clinical entity in which there is massive non-toxic colonic dilatation in the absence of a mechanically obstructing lesion. It is an important yet poorly recognised cause of surgical morbidity and mortality occurring typically in elderly patients with multiple comorbidities. ACPO can often be reversed conservatively with colonoscopic or nasogastric decompression. Surgical intervention is seldom necessary. We present a case of Ogilvie's syndrome in which a healthy 76-year-old man developed life-threatening pseudo-obstruction following rib polytrauma after a mechanical fall. Pneumatosis coli was evident radiologically, prompting emergency exploratory laparotomy. Operative findings of serosal tearing and ischaemic colitis necessitated treatment with right hemicolectomy and ileostomy formation. Microbiological and histopathological analyses proved negative for inflammatory, obstructive and infectious colitides. The case emphasises the importance of early recognition and timely intervention in the management of this rare yet potentially fatal cause of megacolon.

Cholinergic interactions between donepezil and prucalopride in human colon: potential to treat severe intestinal dysmotility

BACKGROUND AND PURPOSE

Cholinesterase inhibitors such as neostigmine are used for acute colonic pseudo-obstruction, but cardio-bronchial side-effects limit use. To minimize side-effects, lower doses could be combined with a 5-HT4 receptor agonist, which also facilitates intestinal cholinergic activity. However, safety concerns, especially in the elderly, require drugs with good selectivity of action. These include the AChE inhibitor donepezil (used for Alzheimer's disease, with reduced cardio-bronchial liability) and prucalopride, the first selective, clinically available 5-HT4 receptor agonist. This study examined their individual and potential synergistic activities in human colon.

EXPERIMENTAL APPROACH

Neuronally mediated muscle contractions and relaxations of human colon were evoked by electrical field stimulation (EFS) and defined phenotypically as cholinergic, nitrergic or tachykinergic using pharmacological tools; the effects of drugs were determined as changes in 'area under the curve'.

KEY RESULTS

Prucalopride increased cholinergically mediated contractions (EC50 855 nM; 33% maximum increase), consistent with its ability to stimulate intestinal motility; donepezil (477%) and neostigmine (2326%) had greater efficacy. Concentrations of donepezil (30-100 nM) found in venous plasma after therapeutic doses had minimal ability to enhance cholinergic activity. However, donepezil (30 nM) together with prucalopride (3, 10 μM) markedly increased EFS-evoked contractions compared with prucalopride alone (P = 0.04). For example, the increases observed with donepezil and prucalopride 10 μM together or alone were, respectively, 105 ± 35%, 4 ± 6% and 35 ± 21% (n = 3-7, each concentration).

CONCLUSIONS AND IMPLICATIONS

Potential synergy between prucalopride and donepezil activity calls for exploration of this combination as a safer, more effective treatment of colonic pseudo-obstruction.

Advances and challenges in the management of acute colonic pseudo-obstruction (ogilvie syndrome)

Although acute colonic pseudo-obstruction (ACPO), also known as Ogilvie syndrome, is a well-known clinical entity, in many respects it remains poorly understood and continues to challenge physicians and surgeons alike. Our understanding of ACPO continues to evolve and its epidemiology has changed as new conditions have been identified predisposing to ACPO with critical illness providing the common thread among them. A physician must keep ACPO high in the list of differential diagnoses when dealing with the patient experiencing abdominal distention, and one must be prepared to employ and interpret imaging studies to exclude mechanical obstruction. Rapid diagnosis is the key, and institution of conservative measures often will lead to resolution. Fortunately, when this fails pharmacologic intervention with neostigmine often proves effective. However, it is not a panacea: consensus on dosing does not exist, administration techniques vary and may impact efficacy, contraindications limit its use, and persistence and or recurrence of ACPO mandate continued search for additional medical therapies. When medical therapy fails or is contraindicated, endoscopy offers effective intervention with advanced techniques such as decompression tubes or percutaneous endoscopic cecostomy providing effective results. Operative intervention remains the treatment of last resort; surgical outcomes are associated with significant morbidity and mortality. Therefore, a surgeon should be aware of all options for decompression-conservative, pharmacologic, and endoscopic-and use them in best combination to the advantage of patients who often suffer from significant concurrent illnesses making them poor operative candidates.

Acute intestinal pseudo-obstruction (Ogilvie's syndrome)

Acute colonic pseudo-obstruction (ACPO), also known as Ogilvie's syndrome, is a condition characterized by massive colonic distension in the absence of mechanical obstruction. Patients presenting with Ogilvie's syndrome have underlying medical and surgical conditions predisposing them to the syndrome. Ogilvie's syndrome can often be managed by conservative therapy. However, unrecognized and untreated, the continued distension associated with Ogilvie's syndrome can lead to perforation that is associated with a high mortality rate. In this article, the pathophysiology, epidemiology, and treatment options are reviewed.

Neostigmine for the treatment of acute hepatic encephalopathy with acute intestinal pseudo-obstruction in a cirrhotic patient

We treated a 49-yr-old man with neostigmine, who had liver cirrhosis, acute hepatic encephalopathy, and acute intestinal pseudoobstruction. He was admitted in a state of hepatic confusion. On physical examination, the abdomen was distended; and bowel sound was absent. Plain abdomen film revealed multiple air-fluid levels and distention of bowel loops. Initially, we gave him lactulose enemas every 6 hr for one day without improvement in his mental state. Furthermore, he became to a state of coma. Therefore, we gave him 0.5 mg of neostigmine subcutaneously to improve his peristaltic movement, and 2 L of polyethylene glycol electrolyte solution through a nasogastric tube for 4 hr to reduce the production and absorption of gut-derived toxins of nitrogenous compounds. After these treatments, the venous ammonia level decreased to the normal range within 12 hr, and the coma disappeared after 2 days. We suggest that neostigmine may be one of the most effective treatments to initiate peristaltic movement and bowel cleansing in cirrhotic patients with acute hepatic encephalopathy and acute intestinal pseudoobstruction.