Nausea and Vomitting

Question 1

What are the four main input systems that can activate the vomiting centre?

Answer 1

Vestibular system

CNS

Chemoreceptor trigger zone

Cranial nerves IX and X

Question 2

How can the inputs to the vomiting centre be used to categorise the causes of nausea and vomiting?

Answer 2

Vestibular system => Vertigo

CTZ = Chemicals in the blood

CNS = Brain problems

Abdo and heart problems = Cranial nerves IX, X

Question 3

What characteristics of the contents of vomit may help with your differetials?

Answer 3

Undigested - Oesophageal disorders

Partially digested - Gastric outlet obstruction, gastroparesis

Bile - Small bowel obstruction (distal to the ampulla of Vater)

Faeculent - Distal intestinal or colonic obstruction

Faecal - Gastrocolonic fistula

Blood/coffee-ground - haematemesis

Large volume - Less likely to be functional

Question 4

What might early morning vomiting suggest?

Answer 4

Pregnancy and raised intracranial pressure

Question 5

Why is it important to ascertain the associated of a patients vomiting with eating?

Answer 5

Vomiting within an hour of eating suggests an obstruction high in the GI tract - peptic ulcer disease can cause scarring

Vomiting after a longer post-prandial delay is consistent with an obstruction lower in the GI tract

Early satiety, post-prandial bloating and abdominal discomfort together suggests gastroparesis or outlet obstruction

Question 6

What other symptoms are important to ask about in patients with nausea and vomiting?

Answer 6

Fever

Headache/visual disturbances

Vertigo

Question 7

Why should you ask patients with vomiting and nausea about their bowel movements?

Answer 7

Delayed/absolute constipation suggests bowel obstruction

Diarrhoea and vomiting suggest infectious gastroenteritis

Question 8

What are important questions to ask someone with nausea and vomiting to work out if they’ve had exposure to infectious?

Answer 8

Close contact with others suffering from VD

Living in close quarters

Recent foreign travel

Unusual meals recently

Antibiotic use

Question 9

Acute (

Answer 9

Gastroenteritis

Food poisoning

Appendicitis

Mesenteric adenitis

Cholecystitis

Pancreatitis

Question 10

Acute (

Answer 10

Small bowel obstruction

DKA

Drug side effects/overdose

Toxins

LBO

Mesenteric ischaemia

MI

Pain

Question 11

Acute (

Answer 11

Meningitis

Raised ICP

Migraine

Question 12

Acute (

Answer 12

Labyrinthitis

Meniere’s

BPPV

Motion sickness

Acoustic neuroma

Question 13

Acute (

Answer 13

Gastric outlet obstruction

Question 14

Chronic (>1 month) nausea and vomiting with weight loss?

Answer 14

Upper GI obstruction: mechanical or functional

Coeliac disease

Question 15

Chronic (>1 month) nausea and vomiting with no weight loss?

Answer 15

Oesophagitis

Pharyngeal pouch

Question 16

How might surgeons approach SBO?

Answer 16

A trial of conservative management

• Fluid and NG aspiration
• Review regularly to ensure he does not deteriorate

Surgery, if:

• There are signs of strangulation or peritonism
• After ~48 hours the obstruction has not resolved
• There is no history of abdominal surgery, making adhesion less likely and more sinister causes more likely

Question 17

What are the 8 types of incision that may be found on the abdomen?

Answer 17

1) Kocher’s (or subcostal) incision: cholecystectomy
2) Rooftop incision: Whipple’s surgery, gastric surgery
3) Transverse abdominal incision for nephrectomy
4) Midline incision: laparotomy, e.g. exploratory, bowel obstruction, gynaecological
5) Paramedian incision: as for midline incision
6) Gridiron or McBurney’s incision: appendicectomy
7) Lanz incision: appendicectomy
8) Pfannesteil incision: Caesarean section, gynaecological operation

Question 18

What is the MOA of cyclizine?

When may its use be indicated?

Answer 18

Antihistamine and antimuscarinic effects that block ACh receptors in vestibular and vomiting centres

Post-operative nausea, bowel obstruction nausea (as it is akinetic), motion sickness and other labyrinthine aetiologies, and also in conditions causing raised ICP

Question 19

What is the MOA of metoclopramide?

When may its use be indicated?

Answer 19

Agonist properties at 5-HT4 receptors and antagonist properties at D2 receptor such as those found in chemoreceptor trigger zone and myenteric plexus of the GI tract

Prokinetic and therefore indicated in causes of delayed stomach emptying eg as a side-effect of opiates, gastroparesis

Question 20

What is the MOA of ondansetron?

When may it be indicated?

Answer 20

5-HT3 serotonin antagonist that acts on receptors in the gut and the chemoreceptor trigger zone

It is useful for chemotherapy induced and post operative vomiting

Question 21

What is the MOA of haloperidol?

When may it be indicated?

Answer 21

An antagonist of D2 receptors such as those found in the chemoreceptor trigger zone and myenteric plexus or the GI tract

It is useful in treating drug-induced and metabolic causes of nausea and vomiting, and also vomiting due to raised ICP