Nausea and vomiting, constipation and malignant bowel obstruction Flashcards
Nausea and Vomiting: What are the 4 categories of causes and some examples of each?
Medications: Chemotherapy, antibiotics, opioids
Pathology:
GI: delayed gastric emptying, bowel obstruction, PUD, gastroenteritis
CNS: vestibular, psych, raised ICP (mass, blood, infection/ abscess)
Metabolic: Liver failure, renal failure, electrolytes (particularly hypercalcaemia)
What are the symptoms of hypercalcaemia?
Stones (kidney stones)
Bones (bone pain, pathological fractures)
Groans (N+V, PUD, pancreatitis)
Thrones (polyuria and constipation)
Psych Moans (lethargy, fatigue, depression, psychosis)
Which 3 cancers are most likely to cause bowel obstruction?
bowel, pancreatic and ovarian cancer (via peritoneal disease)
What is the key feature of N+V in BO?
Vomiting relieves pain and nausea
What is corrected calcium?
- Calcium is bound to albumin, however PARADOXICALLY low albumin concentration will result in an articifically low calcium reading
- In order to correct for low albumin, add 0.02 mmol/L for every g albumin is below 40g/L
What is a basic treatment plan for N+V in palliative care?
6 main classes, what each is mostly used for
Treat underlying cause if possible (eg bowel obstruction)
Medications:
- DOPAMINE ANTAGONISTS
- Metaclopramide (30-80mg subcut/IV): Prokinetic so can’t use in a high grade bowel obstruction (low grade might be useful to de-obstruct)
- (Domperidone, as for metaclopramide above, except it doesn’t cross the BBB)
- Haloperidol: Can use in the setting of BO
CI: Parkinson’s disease (both can cause EPSE)
(Prochlorperazine as for haloperidol)
- ANTIHISTAMINES: 1st generation, sedating H1 receptor antagonist
- Particularly good for N+V caused by raised ICP
- Chlorcyclizine
- Promethazine
- STEROIDS:
- Dexamethasone
- Used in combination with 1st line agents for refractory N+V
+ Haloperidol for intracranial causes
+Ondansetron for chemo causes
OTHER:
- 5HT3 antagonists:
- Ondansetron
Most useful for post-op or chemo induced N+V - PPIs:
- Useful if N+V is due to a gastrointestinal cause - Anticholinergics
- Hyoscine Hydrobromide
- Not much of a role in palliative care, mostly used post op and for motion sickness
Bowel obstruction: HOPC, Ex, Ix?
- Constipation, colicky pain, vomiting, distension, cancer, nausea gets better after vomiting
- Abdo: masses, scars, absent bowel sounds, ascites (ovarian cancer)
- Erect and supine abdo x-ray (>5 air fluid levels) +/- CT abdo
(SB: horizontal markings all the way through- plicae circularis- and centrally placed, LB: haustra; markings not all the way through and peripherally placed)
Management of Bowel obstruction in pall care:
Treat underlying cause if possible
- Requires a well enough patient
Can be accomplished surgically by resection, stent insertion or bypassing the lesion
- Stenting is used for single level obstructions of the oesophagus, pylorus, duodenum, large bowel and upper rectum (ie not small bowel loops)
Medical treatment of bowel obstruction:
- Steroids (dexamethasone): can reduce oedema and swelling to try and relieve obstruction
Symptomatic management:
Food intake:
- If the patient wants oral intake they may tolerate up to 1L fluid/day
- Don’t overhydrate on IVT or they will produce more bowel secretions
- All meds should be subcut because they might not be absorbed properl
Pain relief:
- Opioids
- Hyoscine butylbromide can relieve colicky pain
Reduce secretions:
- Steroids (dexamethasone)
- PPI/ H2 receptor antagonists (ranitidine)
Antiemetics:
- Aim to reduce vomiting as much as possible and inter-vom nausea
- (metaclopramide if small) haloperidol if big (normally used)
+/- NGT
Constipation in palliative care: management plan
Use a bowel chart and monitor patients for constipation
Treat multifactorial underlying causes:
- reduce opioid burden
- reduce anticholinergic meds
- pain on defecation eg anal fissure
- help with mobility
- treat hypercalcaemia
Non-pharmacological management:
- Fibre (eg prune/ pear juice)
- Hydration
- Increased activity
- Regular toileting after meals
Pharm:
1st line:
Combination stool softener and stimulant laxative
eg: docusate and senna
If faeces still hard: More stool softener or osmotic
Increase docusate dose
Add osmotic laxative: Macrogol 3350 or lactulose (if decent fluid intake, draws fluid into bowel)
If bowels still not moving but stool is soft: More stimulant
Eg: Bisacodyl (oral or enema)
Bulking agents eg: psyllium
- NOT USED in pall care as increased bowel transit time and poor fluid intake= may become more constipated
If constipation is caused by opioid use: Give IM methylnaltrexone
What are the causes of hypercalcaemia?
Hyperparathyroidism
Bony mets/ lytic bone lesions
Paraneoplastic: PTHrP released by 4 main tumour types (Lung cancer [mostly squamous cell carcinoma], myeloma, breast cancer, thyroid cancer)
How do you treat hypercalcaemia?
- Rehydration
- Bisophosphonates
- Rank-L inhibitors (denosumab)
What are the 4 goals of bowel care?
Bowel care should address the following: avoidance of pain and discomfort
(abdominal distension; rectal overload; straining), maintenance of dignity (avoidance of incontinence and soiling),
prevention of faecal impaction of the rectum (hard or soft), ability to recognise constipation with overflow (spurious
diarrhoea)
