Palliative Care of Malignant Bowel Obstruction

The presenter has no financial, or other disclosures to provide

Objectives Recognize medical palliative measures and the importance of implementation regardless of approach to treatment. Identify role of endoscopic treatment Identify who benefits from surgical intervention

Malignant Bowel Obstruction (MBO) Occurs predominantly in advanced disease stage Median survival after onset 30-90 days Incidence: 5-51% ovarian cancer 10-28% GI cancer

Non pharmacological symptom management IV hydration (ensure adequacy based on GI output) Electrolyte replacement Environmental controls Decompression NG tube: acceptable for short term management only Often occlude Multiple complications associated with physical, social and psychological discomfort Percutaneous gastrostomy tube preferred when symptoms not able to be controlled with medical or surgical management

Pharmacological management: Pain Should always be controlled, regardless…. Will require opioids, use standard dosing and titration Opioids can aggravate colic by stimulating circular smooth muscle leading to subsegmental contractions Opioid sparing adjuvant drugs should be maximized. Ketorolac may improve colic and pain as well as prevent partial obstruction converting to full. Opioid induced colic can be reduced with anti secretory medications (robinul, scopolamine, sandostantin), which are usually required anyway.

Control of nausea and vomiting requires consideration of pathology Peripheral considerations: Stretch receptors leading to hyperperistalsis and hypersecretion Chemoreceptor trigger zone activation via toxins, drugs, and metabolic derangements Cortex involvement: anxiety, anticipatory nausea and vomiting, triggering through senses Vestibular: less likely etiology in MBO, but may be a factor if dehydrated

Pharmacological interventions to block CRTZ: Ondansetron More effective for chemotherapy and radiation therapy induced nausea and vomiting Considered to have fewer side effects than other medications that interact with CRTZ; however, constipation, and QT prolongation are known side effects and should be considered More expensive than others with similar mechanism Dose: 4mg PO/Iv q4-6h or 8mg PO/IV tid

Pharmacological intervention for blocking the CRTZ: Haldol Considered the most effective for management of nausea and vomiting in MBO Dosing: 0.5-2mg PO/IV/SQ q6h, then titrate Side effects: Drowsiness and extrapyramidal symptoms (if necessary can be offset by low dose Cogentin)

Pharmacological intervention: metoclopramide Generally avoided due to prokinetic effects which increases colic pain and secretions Should only be used in partial obstructions

Management of peripheral etiologies Decompression is essential not only for pain but for nausea and vomiting Anti secretory agents: Decrease distension and pain as well as nausea and vomiting by decreasing peristalsis as well as secretions Somatostatin analogue: Effects same as anti secretory agents with additional decreased gastric acid, bile flow and splanchnic blood flow and increases absorption of water and electrolytes

Scopolamine Dosing: Side effects: Dry mouth, cognitive, visual O.1-0.4mg SC q6h 0.1-0.2mg/h infusion Q72h patch Side effects: Dry mouth, cognitive, visual

Glycopyrolate Dosing: Side effects: 0.2-.04mg SQ or IV q6h prn 0.02mg/h infusion Side effects: Similar to Scopolamine; however, due to being less lipid solubility has significantly lower impact on CNS side effects

Octreotide: mechanism related to decreasing GI hormones Dosing: 50-100mcg SQ q8h 30mg Sandostatin LAR IM Q month Side effects: dry mouth, increased thirst, constipation

Octreotide/Sandostatin Have been shown to be more effective and faster than scopolamine in decreasing GI secretions in patient with NG tube. Decreases intensity and frequency of nausea and emesis May prevent irreversible bowl obstruction in patients with recurrent obstruction

Pharmacological interventions: Corticosteroids In tumor related obstructions are believed to decrease peri luminal inflammatory edema, increase intestinal mobility as well as decrease nausea.

Gastric outlet obstruction: endoscopic scope placement vs Gastrojejunostomy Endoscopy with stenting: In appropriate patients has increased success rate over gastrojejunostomy: Shorter time to oral intake Lower morbidity Lower rate of delayed gastric emptying Shorter length of stay

Gastric outlet obstruction: endoscopy vs gastrostomy tube Gastrostomy tube indicated over endoscopy: Life expectancy less than 1 month Rapidly progressing disease Ascites Carcinomatosis Multiple obstruction sites

Endoscopy with stent : Benefit Used as a bridge to surgery, or for symptom relief if not surgical candidate Allows time to mitigate co morbidities, enhance nutrition, and complete staging

Endoscopy with stent: Contraindications Perforation with peritonitis Rectal tumor within 2cm of anal margin (associated with tenesmus and fecal incontinence)

Endoscopy with stent: Complications Migration: Incidence 10% Usually asymptomatic but ½ need repeat intervention Bleeding 5% Perforation: Incidence 4% Incidence 10% when dilatation performed with stent placement Recurrent obstruction rate 10%

Considerations for determining if surgical intervention is appropriate: Surgery provides a 10 fold or greater chance of 30 day survival in large bowel obstruction Surgery generally considered contraindicated in patients with 30 day or less prognosis Not all who have a better than 30 day prognosis benefit from surgical intervention

Short term prognosis scoring system: Radiographic evidence of carcinomatosis 1 point Radiographic evidence of ascites 1 point Complete small bowel obstruction 1 point Hypoalbuminemia 1 point Leukocytosis 1 point Score of greater than 4 associated with 30 day survival of less than 60%

Nomogram to determine if surgery will provide benefit in SBO Radiographic evidence of carcinomatosis 1 point Leukocytosis 1 point Hypoalbuminemia 1 point Non- gynecological cancer 1 point 0-1 point surgery recommended 2 points surgical and non surgical approaches have equal outcomes 3-4 points risks and Burdon outweigh surgical benefit

Summary: All patients should receive aggressive pharmacological symptom management which usually requires multiple medications Endoscopy with stent placement has few contraindications and low complication rate and should be considered as a bridge to surgery or for symptom management in patients who are not surgical candidates Three considerations when deciding if surgery is appropriate LBO vs SBO Short term prognosis Apply nomogram to determine if patient will receive benefit from surgical intervention

Resources and References S. Soriano, MD, D. Mellar, MD. Malignant Bowel Obstrution: Indiidualized treatment near the end of life. Cleveland Clinic Juournal of Medicine. Volume 78. March 2011. J. henry, MD et al. A scoring system for the prognosis and treatment of malignant bowel obstruction. Surgery. 2012 October: 153(4): 747-757. doi: 10.1016/j.surg. 2012.07.009. EPEC: Education in Palliative and end of life care Modules: Bowel obstruction, and Nausea and vomiting.