GI and Liver 3 Flashcards
Summarise bilirubin metabolism
Bilirubin is produced as a result of breakdown of haem from haemoglobin
= conjugated bilirubin
Unconjugated bilirubin metabolised by liver cells to a soluble conjugated form and is excreted via the hepatic and bile ducts into the duodenum
Bilirubin and bile salts in the bowel aid absorption of fats and fat-soluble vitamins
What happens to conjugated bilirubin?
Approx half of conjugated bilirubin is reabsorbed from the bowel as urobilinogen in the enterohepatic circulation
Urobilinogen may be excreted in urine or remetabolised through the liver
In jaundice - excessive conjugated bilirubin may be excreted in the urine, causing urine to be dark
What are some of the commoner causes of jaundice in childhood?
Mostly unconjugated: - Haemolytic disease of the newborn - Sickle cell disease - Spherocytosis Rarely: - Hepatic (rare)
Mostly conjugated - Hepatitis - CF - Cirrhosis Obstructive: - Hepatitis - Biliary atresia
What is important to ask in a history of jaundice?
Insidious vs sudden onset - first sign of insidious onset is yellowing of sclera
- haemolysis is usually rapid onset
Malaise
- Duration of malaise, abdo pain, anorexia
Symptoms of anaemia
- Occurs as a result of haemolysis
Pruritus
- Intense skin irritation as a result of bile salts in the skin
Urine colour
- Very dark indicated conjugated bilirubin is the cause
Steatorrhoea
- Frothy, foul-smelling stool which floats in toilet
- Commonly seen in children with long-standing cirrhotic liver disease
What may be found on physical examination of a jaundiced child?
FTT or poor growth
Skin signs:
- Scratch marks on skin
- Signs of long-standing liver disease including spider naevi, clubbing and ascites
Hepatosplenomegaly
- Hard liver suggests cirrhosis
- Splengomegaly can suggest haemolysis or cirrhosis
What may bloods reveal in a jaundiced child?
Hb:
- Low Hb with increased reticulocytes indicates haemolysis
Bilrubin:
- Unconjugated = haemolysis
- Conjugated = hepatic / post-hepatic
Liver enzymes:
- Raised in hepatitis
Alkaline phosphatase:
- Elevated in cirrhosis or in cases of long-standing jaundice
Serology
- Identification of hepatitis virus
What is the most common cause of jaundice in older children?
Hepatitis A
What is Reye’s syndrome?
Acute encephalopathy associated with fulminant liver failure
Can be induced by aspirin
What metabolic syndromes can lead to progressive jaundice?
Wilsons disease
- Defect in copper metabolism
- Leads to neurodevelopmental delay and FTT
- Brown ‘Kayser-Fleischer rings’ around cornear
What enzyme defects can lead to chronic hyperbilirubinaemia?
Criggler-Najar disease
- Glucuronyl transferase deficency
Gilbert’s syndrome
- Bilirubin uridine diphosphate glucuronosyltransferase enzyme
What is mesenteric adenitis?
Diagnosed where no other cause for acute abdo pain can be found
Caused by acute enlargement of intra-abdo LN as a result of infection in URTI, chest or gastroenteritis
These enlarged LN cause pain
How may mesenteric adenitis present?
Recent hx of infection and signs may still be present in chest or throat
Fever, malaise, central abdo pain
NEVER peritonism or guarding = diagnosis of exclusion
What is the management of mesenteric adenitis?
Exclude other conditions
Expectant management - usually resolves within 24-48hrs
Analgesia
What is pyloric stenosis?
Hypertrophy and hyperplasia of the pylorus muscle
Results in narrowing of the pyloric canal which can then easily become obstructed
When does pyrloric stenosis usually develop? In who?
First 4-6 weeks of life
M:F 7:1
Most common in firstborn male children
How does pyloric stenosis present?
Projectile vomiting during or immediately after feeding
- But not necessarily at every feed
Infant hungry and ready to take another feed immediately
Vomit may be blood tinged but not bile-stain
Weight loss and dehydration often seen
Constipation
What may be noted on examination of an infant with pyloric stenosis?
Visible peristalsis from the LUQ to RUQ immediately after a feed or just prior to vomiting
Hard mobile tumour ‘olive mass’ to R of epigastrium
How should pyloric stenosis be investigated?
If olive ass found, no need for barium studies or USS
If diagnosis suspected but tumour not palpable, confirm with USS
What may occur as a result of prolonged vomiting in pyloric stenosis?
Loss of acidity from stomach leads to hypochloraemic alkalosis and reduced sodium and potassium levels in serum
What is the management of pyloric stenosis?
Surgical treatment
- Ramstedt procedure involves splitting pyloris muscle without penetrating the mucosa
- If infant is dehydrated rehydration must take place prior to surgery with replacement of sodium, chloride and potassium
- Oral feeds can be given within hours postoperatevely
What is the pathophysiology of hypochloraemic, hypokalaemic metabolic alkalosis?
Hydrogen chloride loss from vomiting leads to hypochloraemic metabolic alkalosis
Renal compensation by maximising bicarb reabsorption
Exchange of potassium and sodium for hydrogen ions in DCT
What is testicular torsion?
More accurately = torsion of the spermatic cord
Common urological emergency
Causes occlusion of testicular blood vessels
Unless rapidly treated leads to ischaemia, leading to loss of the testis
(Germ cells are the most susceptible cell line to ischaemia)
What are the two types of testicular torsion?
Intravaginal
Extravaginal
What is intravaginal testicular torsion?
Secondary to the lack of normal fixation of the posterior lateral aspect of the testes to the tunica vaginalis
Results in testis being free to swing and rotate within the tunica vaginalis of the scrotum
= “bell-clapper deformity”
What % of testicular torsions are intravaginal and what % of these are bilateral?
Intravaginal testicular torsion = 12% males
40% bilateral
What is extravaginal testicular torsion?
Occurs more often in neonates and occurs in utero or around the time of birth, before the testis is fixed in the scrotum by the gubernaculum
Thus both the spermatic cord and tunica vaginalis undergo torsion together, either in or just below the inguinal canal
How does testicular torsion present?
Sudden, severe pain in one testis
- Often during sport / physical activity
- May be associated lower abdo pain
Often hx of a previous similar episode
+/- n&v
Is easing pain a good sign in testicular torsion?
Not necessarily - pain also eases as necrosis sets in
What may be found upon examination of testicular torsion?
Reddening of scrotal skin
Swollen, tender testis retracted upwards
Lifting testis up over symphysis increases pain
- Unlike epididymitis where this relieves pain
What test can be performed to check for testiclar torsion?
Looking for absence of cremasteric reflex
- 100% sensitivity and 66% specificity for testicular torsion
- L1/L2 spinal nerves elicited by gentle pinching or stroking of the inner thigh while observing the scrotal contents
Who does testicular torsion typically affect?
Neonates and post-pubertal boys
Peak 12yrs
But can affect all ages
Which side is more commonly affected by testicular torsion?
L more than R
Bilateral rare
Ddx testicular torsion (4)
Epididymitis, orchitis or epididymo-orchitis
- Usually from reflux of infected urineor from STI
Hydrocele
- Painless and transilluminatable
Incarcerated hernia
Testicular tumour
- Rarely painful
Mumps
- Swelling of parotid glands
- Mumps orchitis rare before puberty
What investigations are done for testicular torsion?
All cases of acute testicular pain are torsion unless proved otherwise
= URGENT TREATMENT
What is the management of testicular torsion?
Prompt surgical exploration is required to untwist and fix testis to the scrotum
What is the prognosis of testicular torsion?
If corrected within 6 hours, good prognosis
If >24hrs - may have become necrotic and require removal
The contralateral testis must also be fixed as it is also prone to torsion
What is biliary atresia?
Important but rare condition
Caused by atresia of intrahepatic or extrahepatic bile ducts
How do babies with biliary atresia present?
Persistent jaundice with rising conjugated bilirubin
Pale, chalky stools
From 4 weeks of life
What happens if biliary atresia goes undiagnosed?
Rapid progression to liver failure and death
But if diagnosed within 3 months - surgery can resolve liver function to near normal
How is biliary atresia managed?
Urgent referral for assessment
Diagnostic isotope scan and surgical correction
- Kasai procedure
What is cryptorchidism?
Undescended or ectopic testes
How can undescended or ectopic testes be differentiated?
Only during operation
How does cryptorchidism occur?
Usually the testes descend from their fetal intra-abdo position through the processus vaginalis and into the scrotum during the 7th month of gestation
The undescended testicle is found along the normal path of descent and the processus vaginalis is usually patent
If bilateral - consider hypopituitarism
Ectopic testicle is one that has completed its path of descent through the inguinal canal but ends up at the wrong destination, usually in the groin
How does cryptorchidism present?
Asymptomatic
What may be found on examination of a child with cryptorchidism?
Warm rooms and warm hands
Testes impalpable or high in inguinal region or scrotum
Empty hemi-scrotum
+/- inguinal hernia
Attempt to bring testis down into position by sweeping massage into inguinal region (differentiates from retractile testis)
What investigations are performed for cryptorchidism?
Clinical diagnosis
USS can help to locate testis
Hormonal testing if testes impalpable bilaterally
Who are more likely to be affected by cryptorchidism? How common is it?
Premature babies
5% undescended at term
1% by 12 months
(Spontaneous descent may occur in first 6 months but unlikely after this)
What often accompanies cryptorchidism?
Inguinal hernia
What is the management of cryptorchidism?
Surgery - ochidoplexy if not spontaneously resolved by one year (most do by 6 months)
- Important to be before age 2 yrs (by this age the number of germ cell s in the undescended is already reduced and the risk of infertility is increased, whether unilateral or bilateral)
Other than reduced fertility, what is a risk of delayed surgery in cryptorchidism?
Testicular tumour
What % of undescended testis are palpable and impalpable? Where are they and how should they be managed?
Palpable = 80%
- Usually in inguinal canal
- Tests can be bought down into scrotum, referred to paediatric surgeon at one year
Impalpable = 20%
- Either intra-abdo (risk of malignant degeneration), inside the canal or absent
- Investigate with laparoscopy
What is the most common cause of hepatitis?
Viral infections:
- Hep A (most common)
- Hep B
- Hep C (rare)
- EBV
- CMV
How is Hep A transmitted?
Faeco-oral route
Associated with poor hygiene and limited sanitation
What age group has the highest incidence of Hep A? What is the incubation period?
Age 5-15yr
2-6 weeks
How is hep B transmitted and prevented? What is the incubation period?
Blood products eg vertical transmission from mother to baby - however if mother has hepatitis B antibodies her baby is protected
Immunisation of the newborn infant is possible if the infected mother is recognised antenatally
2-6 months
How does Hep A present?
Insidious onset
Child is unwell with anorexia, nausea, and jaundice appears 5 days later
Pale stools and dark urine
What may be found on examination of a child with hep A?
Tender but not enlarged liver
What may be found on investgiation of a child with hep A?
LFTS - high transaminases and raised conjugated hyperbilirubinaemia
Identify virus serologically
How is hep B serologically investigated?
Presence of hep B surface and core antigens
How is viral hepatitis managed?
No specific treatment
Hep A highly infectious during prodromal phase but by the time jaundice has presented the pt is no longer excreting the virus
Hep B highly contagious
What is the prognosis of viral hepatitis?
Hep A - good prognosis and rare to develop chronic hepatitis
Hep B - more common to develop chronic hepatitis, and increased risk of developing subsequent hepatocellular carcinoma in adult life for carriers
What is Crohn’s disease?
Type of IBD that may affect any part of the GI tract from mouth to anus
Discontinuous mucosal involvement
Cobblestoning in severe vases
How does Crohn’s disease present?
Recurrent abdo pain Anorexia Growth failure Fever Diarrhoea Anaemia Oral and perianal ulcers Arthritis
How is Crohn’s disease diagnosed?
Endoscopic biopsy
How is Crohn’s disease managed?
Remission induced by:
- Elemental diet
- Immunomodulator drugs
- Anti-TNF drugs eg infliximab
- Steroids
For localised disease surgical resection may be indicated
What is ulcerative colitis?
Inflammation with ulcer formation in the lining of the colon
Continuous
How does ulcerative colitis present?
Bloody diarrhoea
Abdo pain
Possibly:
- Weight loss
- Arthritis
- Liver disturbances
What is the management of ulcerative colitis?
Mesalazine - PO or PR
Steroid enemas
Severe cases:
- Immunosuppressive therapy
- Infliximab
- Colectomy
What is toddlers diarrhoea?
Toddlers often experience non-specific diarrhoea probably due to rapid gastrocolic reflex
How does toddlers diarrhoea present?
Diarrhoea
Drinking excessive fluids esp fruit juices
Food particles in stool
How is toddlers diarrhoea diagnosed?
Only is child is thriving
How is toddlers diarrhoea managed?
Reassurance
What is a volvulus?
Torsion of a mal-rotated intestine
How does volvulus present?
Severe abdo pain with bilious vomiting
How is volvulus treated?
Urgent surgery to untwist the volvulus and treat underlying malrotation
If missed bowel may infarct
