Hyperemesis Gravidam

Question 1

Definition of Hyperemesis Gravidarum

Answer 1

• A condition where vomiting is persisten and subsequently inteferes with fluid intake and nutritional status resulting in malnutrition, and/or weightloss, fluid/elecetrolyte/acid-base imbalances.*
• Characterised by persistant vomiting, volume depletion, ketosis, electrolyte disturbances and weight loss (>5%)*

Question 2

What are the current theories to the cause of hyperemesis gravidarum

Answer 2

• Increased oestrogens cause decreased gastric mobility and delayed gastric emptying
  
  • this leads to an altered pH and increased H.pylori colonisation
• The B subunit of B-hcg is thought to stimulate secretory process in the upper GI tract
  
  • it’s also structurally similar to TSH and may cause hyperemesis through stimulation of TSH receptors

Question 3

Why is there concern surrounding hyperemesis gravidarum?

Answer 3

The combination of nutritional inadequancy, electrolyte imbalance and vitamin deficiencies can cause amternal and fetal morbidity.

Question 4

How to distinguish and characterise hyperemesis gravidarum from nausea and vomiting in pregnancy

Answer 4

Three major categories

• Without Volume Depletion
  
  • ‘normal moring sickness’ (70-85%)
  • Mild and self-limiting
• With volume depletion and electrolye imbalance
• Persistant vomiting, volume depletion, electrolyte imbalance, ketosis and >5% weightloss
  
  • Hyperemesis Gravidarum (0.5-2%)

Question 5

What symptoms or signs should prompt you to admit and/or give IV rehydration in a pregnant women with N&V

Answer 5

If signs/symptoms: of ketosis, electrolyte imbalance, volume depletion

Symptoms such as:

• Severe N with vomiting >3/day, smelly/sweet breath, unable to tolerate oral nutrition, lethargy, oliguria, dry mouth, thirst

Signs Such as:

• Dehydration: tachycardia, poor tissue turgor, dry mucosa, low JVP
• Malnutrition: WL >5%, anaemia, low consciousness

Question 6

Although we can assume hyperemesis gravidarum or N&V, hat are important differentials not to be missed!

Answer 6

• Hyditaform mole (molar pregnancy)
• Multigestational pregnancy
• Hyponatraemia
• Non-pregnancy related causes: hepatitis, gastroenteritis, pyelonephritis, appendicitis, pancreatitis, bowel obstruction, raised ICP

Question 7

What are some important complications to not miss with HG

Answer 7

• Mallory Wise Tear
• Vitamin B12 and B6 deficiencies
• Wernickes encephalopathy (thiamine deficiency)
  
  • confusion, ocular abnormalities, ataxia
• Depression
• Thrombosis
• Hyponatraemia: can get central pontine myelinolysis if Na replacement is too fast

Question 8

What investigations do you want for a patient with hyperemesis gravidarum

Answer 8

• FBC: anaemia, infection
• LFT
• U and E: electrolyte imbalances
• Urinalysis: ketonuria, UTI, pyelo
• Fetal USS: ?multiple gestation

Question 9

How do you treat HG

Answer 9

Correct the imbalances:

• IV 0.9% N saline + potassium (+MG dependent on levels)

Prophylaxis:

• Folic acid
• Thiamine (B1) 50mg PO OD
• Pyridoxine (B6)50mg PO OD

Relief of Symptoms:

1. Metaclopramide 5-10mg Q6H
2. Cyclizine 5-10mg PO Q6H
3. Ondansetron 4-8mg Q8H

Also

• support/reassure
• small dry meals, eat when least nauseous
• oral ginger
• corticosteroid (only if severe)

Question 10

Why do we NOT use dextrose infusions?

Answer 10

increase the risk of thiamine deficiency (wernicjes encephalopathy)