Bowel Obstruction

1. Bowel Obstruction Becky Owen 22/2/12

2. Overview • Case Study • Clinical Presentation • Management • Case Study Update • Summary • Questions

3. Mrs JL • 55 yr Ovarian Carcinoma • Diagnosed 2010 • 4 cycles palliative chemotherapy • Stable disease until June 2011 • Increased abdominal distension, nausea, vomiting, weight loss • CT – disease progression, subacute small bowel obstruction • What would you do next?

4. Bowel Obstruction in Palliative Care • Due to functional or mechanical obstruction of bowel lumen and/or peristaltic failure • Can be partial or complete • Can occur at any level • Oesophageal • Gastric outlet & proximal small bowel • Distal small bowel • Large bowel

5. Causes • The cancer itself • Past treatment • Adhesions, postradiation ischaemic fibrosis • Drugs • Opioids, antimuscarinics • Debility • Faecal impaction • Unrelated benign condition • Strangulated hernia

6. Clinical Picture • Abdominal pain • Abdominal distension • Vomiting • Nausea • Intestinal colic • Variable bowel habit

7. Bowel obstruction – Pathophysiology • Partial or complete bowel obstruction • Reduction or stop movement Increased bowel contractions • Intestinal content  • Increased bowel distension Increased luminal content • Increased gut epithelial surface area • Increased bowel secretions (H2O, NaCl) • Damage epithelium • Oedema and hyperaemia • Production noiceceptive mediators • Continuous pain Colicky pain  • Nausea and vomiting

8. Management - Surgery • Consider if; • Single discrete organic obstruction i.e. adhesions, isolated neoplasm • Good performance status • Patient willing to undergo surgery • Contra-indications; • Previous laparotomy findings preclude prospect of successful intervention • Diffuse intra-abdominal carcinomatosis • Massive ascites (re-accumulates rapidly after paracentesis)

9. Management - Medical • Focus on symptomatic relief • Anti-emetics • Opioids • Review laxatives • Corticosteroids • Anti-secretory drugs • Octreotide

10. Anti-emetics • Patient without colic + passing flatus – Prokinetic first drug of choice • Patient with colic – antisecretory + antispasmodic drug (Buscopan) • To be aware of anti-cholinergic effect of some drugs – can inhibit gut motility

11. Octreotide • Synthetic analogue of somatostatin with longer duration of action • Inhibitory hormone – found throughout the body • Inhibits release of Growth Hormone, TSH, Prolactin, ACTH in hypothalamus • Inhibits peptides of Gastro-enteropancreatic system

12. Octreotide and bowel obstruction • <50% patients – respond to typical starting dose of 300 micrograms/24hr • 75-90% respond to 600-800 micrograms/24hr • Comparisons with buscopan – Octreotide more effective and rapid relief of nausea, vomiting and reduced NG output • NB after 4-6 days overall symptom comparison is similar • Lanreotide – alternative sandostatin analogue available in depot formations

13. Octreotide and ascites • Can suppress diuretic induced activation of renin-aldosterone-angiotensin system • May interfere with ascitic fluid formation by reducing splanchnic blood flow or as a result of a direct tumour anti-secretory effect • May also help improve efficacy of diuretics in cirrhosis

14. Undesirable effects from Octreotide • Bolus SC injection painful • Dry mouth • Flatulence • Nausea • Abdominal pain • Diarrhoea • Impaired glucose tolerance • Gallstones

15. Cautions • Insulinoma • Type 1 diabetes • Cirrhosis • Renal Failure • Avoid abrupt withdrawal of short-acting octreotide after long-term treatment • Monitor thyroid function

16. Octreotide Drug Interactions • Octreotide markedly reduces plasma ciclosporin concentrations and inadequate immunosuppression may result.

17. Octreotide CSCI Compatability • 2 drug compatibility data for octreotide and; • Morphine sulphate, metoclopramide, hyoscine butylbromide, diamorphine, alfentanil (in WFI) • Check PCF4 / palliativedrugs.com • Conflicting observational reports with levomepromazine

18. Depot Formulation of Octreotide • Sandotatin – 10-30mg every 4/52 • Relative bio-availability of 60% compared to SC • Deep IM injection • Used in patients with symptoms already controlled with octreotide therapy • Lanreotide – 60mg every 4/52 • ‘Somatuline Autogel’ preparation can be given SC

19. Management - Interventions • Dependant on level and extent of obstruction • Stents • Venting gastrostomy

20. Mrs JL Cont. • Not suitable for surgery/intervention • No colic – initially trialled metoclopramide CSCI • Not effective – converted to levomepromazine CSCI (12.5mg over 24 hr) • Ongoing large volume vomits – octreotide added to CSCI (1 mg over 24 hr) • Helped stabilise symptoms and allow for period of 6/52 at home with family

21. In Summary • One of the most challenging problems in palliative care • To focus on improving quality of life • If focal obstruction – consider possibility / suitability of intervention • Rarely need IV fluids or NG tube to relieve symptoms

22. Any Questions?

23. References • Palliative Care Formulary 4th Edition; R Twycross, A Wilcock. • Symptom Management in advanced cancer 3rd Edition; R Twycross, A Wilcock.