Nausea and Vomiting Flashcards
Where is the vomiting centre, what receptors does it contain and what are the 4 main inputs
Medulla Oblongata
Mainly histamine and ACh
Inputs: vestibular system, CNS, chemoreceptor trigger zone (4th ventricle), CN IX and X
What general questions about the PC of vomiting
Contents Timing Association with eating Details of pain Associated symptoms Bowel movements Bowel pathogen exposure
What questions should be asked about PMHx for vomiting
Drugs
Abdominal surgeries
What does the contents of the vomit suggest (undigested, partially digested, green, faeculent, blood, large volume)
Undigested food: oesophageal disorder (achalasia, pharyngeal pouch)
Partially digested: gastric outlet obstruction, gastroparesis e.g. DM
Bile (green): small bowel obstruction (distal to ampulla of vater)
Faeculent: distal intestinal or colonic obstruction
Blood/coffee ground: haematemesis
Large volume: less likely functional
What does the timing of vomit suggest (early morning, early vs late presentation)
Early morning - pregnancy and raised ICP
Early presentation - more likely severe
What does vomiting that is associated with eating suggest
Within an hour: obstruction in the upper GI tract, proximal to gastric outlet - ask about peptic ulcer disease or dyspepsia history
Longer post-prandial delay - obstruction in lower GI tract, usually small bowel
Early satiety, post-prandial bloating and abdominal discomfort - gastroparesis or outlet obstruction
What are the following symptoms (with the vomiting) associated with
Fever - infectious of inflamm e.g. gastroenteritis, appendicitis, cholecystitis, cholangitis, pancreatitis etc.
Headache, visual disturbance, neuro symptoms - meningitis, encephalitis, migraine, raised ICP
Vertigo, balance isssues - labrythnitis, Meniere’s, BPPV
What does a patient’s bowel movements suggest (with vomiting)
Delay- long delay suggests obstruction
Constipation - may be due to eating less and then vomiting, but absolute (faeces AND flatus) is serious sign of bowel obstruction
Diarrhoea - infectious gastroenteritis
What questions should be asked to ascertain their exposure to infectious bowel pathogens
Any close contacts with the same symptoms? - suggests rotavirus, adenovirus, norovirus (contagious) or sharing of contaminated food S aureus
Living in close quarters? e.g. hospital, army, boarding school, cruise ship
Recent foreign travel?
Unusual meals recently? e.g. barbecue, wedding buffet, late-night kebab, restaurant
Which drugs and toxins may lead to vomiting and nausea
Medications - opiates, chemotherapy, anitconvulsants, antibiotics etc.
Industrial chemicals - arsenic acid and organophosphate fertilisers
Alcohol and illicit drugs
What is the significance of previous abdominal surgery to N+V
Prediposes to adhesions (between peritoneum and bowel) -> obstruction
What are some red flag symptoms with N+V and their suggested cause
Motionless, rigid abdomen Bilious or faeculent vomiting, distended abdomen, constipation and pain Very high fever Early morning + headache Central, crushing chest pain Meningism Reduced consciousness Haematemesis
What are the suggested conditions with the following red flag symptoms:
Motionless, rigid abdomen
Bilious or faeculent vomiting, distended abdomen, constipation and pain
Very high fever
Early morning + headache
Central, crushing chest pain
Meningism
Reduced consciousness
Haematemesis
Motionless, rigid abdomen - peritonitis
Bilious or faeculent vomiting, distended abdomen, constipation and pain - bowel obstruction
Very high fever - infection
Early morning + headache - raised ICP
Central, crushing chest pain - MI
Meningism - meningitis
Reduced consciousness - DKA, meningitis, raised ICP
Haematemesis - varices, bleeding peptic ulcer
What signs should be examined for with presentation of N+V on inspection
Hydration status - look at mucous membranes and ask if thirsty Abdominal distension Scars - ?previous surgery Hernias Jaundice
What signs should be examined for with presentation of N+V on palpation and auscultation
Tender - inflammation
Signs of dehydration - cold peripheries, delayed CRT
Masses
Guarding and rigidity
Bowel sounds - absent (ileus) or tinkling (obstruction)
What bloods should be ordered for N+V
FBC and CRP U&Es VBG Liver enzymes Amylase Group and save
What imaging should be ordered for N+V (suspected obstruction)
Supine AXR Erect CXR (patient must sit up for 10 mins)
What “other” investigations should be ordered for N+V
Pregnancy test Toxicology screen Contrast studies Abdominal CT Head CT
How is a small bowel obstruction managed before referral to surgery
NBM
Drip and suck 0 IV fluids and aspiration via NG tube
Analgesia (avoid opiates and NSAIDs)
Antiemetics
What are the indications for surgery for small bowel obstruction
Trial conservative management (drip and suck) fails
Signs of strangulation or peritonism
>48 hours after obstruction and it has not resolved
No Hx of abdominal surgery
How does DKA present
Vomiting Abdominal pain Polydipsia Polyuria Headache Decreased consciousness and Kussmaul breathing
How is anion gap calculated and if it is raised what does it suggest
[K+] + {Na+] - [Cl-] - [HCO3-]
presence of extra anion groups in the blood e.g. ketone, lactate, aspirin rather than lack of bicarbonate
What is the acute management for DKA
ABCDE IV fluids IV insulin infusion Potassium Consider correcting acidosis with bicarb (rare)
What advice/medications can be offered to pregnant patients with morning sickness/nausea
Eating smaller meals more slowly
Dietary adjustments e.g. avoid spicy, fatty, acidic foods
Anti-emetics e.g. antihistamines (promethazine), electrolyte replacement, thiamine supplements
Severe (hyperemesis gravidarum) - prochlorperazine, chlorpromazine, metoclopramide, ondansteron
