Gastro L-M

Question 1

What is Lactose intolerance?

Answer 1

Inability to metabolise lactose due to lactase deficiency.

Question 2

What is the background of Lactose intolerance?

Answer 2

Congenital is extremely rare, primary in 5% of children.

Congenital: AR condition

Primary: natural non persistence of enzymes after birth, mainly in Asian population.

Secondary: damage to brush border following gastroenteritis.

NOT the same thing as CMPA. Disaccharide enxymes normally at brush border, break down lactose into glucose and galactose. 50% activity required for effective metabolism.

Question 3

What history and exam findings would you see in Lactose intolerance?

Answer 3

Gi Hx: loose stools, frothy and explosive, bloating, cramping, flatus. II: ask about gastroenteritis recently.

Congenital: infantile diahrrea and failure to thrive.

Primary: GI symptoms increase with age due to progressive loss. Wide variety in amount of lactose expressed.

Question 4

What investigations would you use for Lactose intolerance?

Answer 4

Hydrogen breath test: detects H2 in breath 3-6 hours after ingestion of lactose.

Stools for reducing substances: acidic as have undigested sugars.

Jejunal biopsy: rarely needed, differentiate from coeliac.

Question 5

What is the management of Lactose intolerance?

Answer 5

Lactose is only in mammalian milk. Congenital require lifelong absolute abstinence from milk. Beware of Ca supplementation in replacement products.

Primary: low lactose diet can be tolerated.

SecondaryL complete avoidance for 4-6w to allow mucosal regeneration

Question 6

What are the complications and prognosis of Lactose intolerance?

Answer 6

Malabsorption, failure to thrive, Ca deficiency if on different milk for Tx.

Congenital is a lifelong condition. Primary is variable depending on level of residual lactase. Secondary is transient.

Question 7

What is Liver disease, Chronic?

Answer 7

Chronic disease of hepatic cells, leading to decrease in overall liver function.

Question 8

What is the background of Liver disease, Chronic?

Answer 8

FHx, Hx of infection. HBV: 5% infected in world. The younger the infection the higher the rates to chronic conversion. HCV infection in 1% worldwide, cirrhosis interval 10-15y. AI hepatitis 0.1/100k. Wilsons 1/30k.

Aetiology:
Chronic active hepatitis:

· AI disease of parenchyma (AIH) or biliary tree (PSC) (-> inflammatory infiltrate with hepatocellular necrosis)

· Viral: HBV, HCV. (-> death of hepatocytes at interface between parenchyma and CT, with lymphocyte infiltration)

· DrugsL NSAID, Abx, AEDs, paracetamol.

Wilsons disease: hepatolenticular degeneration due to Cu deposits in brain, liver, kidney and cornea. (-> AR gene 13 mutation with low serum ceruloplasmin/ defective bile excretion of Cu).

Cystic fibrosis.

Question 9

What history and exam findings would you see in Liver disease, Chronic?

Answer 9

Acute or insidious presentation

General fever, malaise, failure to thrive, loss of fat and muscle bulk.

GI: distended abdomen, scrotal swelling, dilated abdominal vein (portal HTN)

AI hepatitis: skin rash, lupus, arthritis, AIHA. Nephritis.

Wilson: KF ring >7y, neuro features >12y parkinonian.

Question 10

What investigations would you use for Liver disease, Chronic?

Answer 10

HBV/HCV serology and surface antigen screen

AI hepatitis anti SMA Ab, IgG levels (IgG >20mg/l), ANA in PSC, liver/kidney microsomal antibodies.

Wilson disease: gene 13 mutaiton, low serum ceruloplasmin/copper. High urinary copper and hepatic copper.

Question 11

What is the management of Liver disease, Chronic?

Answer 11

HBV: immunize at risk, support, aIFN.

HCV: aIFN.

AI hepatitis 90% respond to prednisolone/AZA

Wilson: Penicillamine (reduces hepatic/CNS copper), Zn (reduces Cu absorption), pyroxidone (prevents peripheral neuropathy) ? think of transplant

Question 12

What are the complications and prognosis of Liver disease, Chronic?

Answer 12

End stage liver disease, coagulation and electrolyte disturbances.

Depends on underlying pathology. Px improved with adequate tx of underlying condition. AI has best prognosis.

Question 13

What is Hepatitis, Acute?

Answer 13

Acute failure of hepatic cells to maintain normal function.

Question 14

What is the background of Hepatitis, Acute?

Answer 14

Aetiology
Damage to hepatocytes caused by:

· InfectionL acute HepA/HepB, EBV

· DrugsL paracetamol, isoniazid, halothane, Amanita phalloides.

· Reye syndrome aspirin in patients<14y, associated with acute non inflammatory encephalopathy associated with liver damage (especially if with varicella). Shows microvescicular infiltration of the liver on pathology.

Epidemiology
Uncommon in children, EBV in adolescents.

Question 15

What history and exam findings would you see in Hepatitis, Acute?

Answer 15

General: jaundice, encephalopathy, coagulopathy, hypoglycaemia, other electrolyte disturbances.

Encephalopathy: drowsy, alternating irritability and drowsiness. Older may have hx of aggression and being difficult.

Question 16

What investigations would you use for Hepatitis, Acute?

Answer 16

Blood: high BR, deranged clotting, high LFT, high NH4, glucose check

ABG: may have metabolic acidosis or alkalosis

Viral serology: hep EBV

CT.MRI brain to exclude encephalopathy

Question 17

What is the management of Hepatitis, Acute?

Answer 17

Tx complications, including:

· Hypoglycaemia: dextrose infusion

· Sepsis: IV BSAbx

· Coagulaton defects: FFP and H2 blockers/PPI to prevent gastric bleed. Vit K to be avoided unless necessary.

· Verebral odema: Hyperosmolar therapy

· Liver transplant with worsening clinical and biochemical profile.

Question 18

What are the complications and prognosis of Hepatitis, Acute?

Answer 18

Cerebral odema, haemorrage from gastritis, sepsis, pancreatitis

High mortality though uncommon. Poor signs include shrinking in size, rising BR with falling transaminases, coagulation defects, progression to encephalopathy and coma. Patients in coma have 70% morality if no transplant.

Question 19

What is Malrotation of the intestine?

Answer 19

Failure of normal embryological rotation of the SI around the SMA during development, predisposing to obstruction, volvulus and ischaemia.

Question 20

What is the background of Malrotation of the intestine?

Answer 20

1/500, Common PM finding.

Normal rotation around SMA in three stages – Stage I herniation, Stage II return to abdomen with 270 counterclockwise rotation, stage III fixation.

Non rotation: midgut only rotates 180

Incomplete rotation: duodenal loop lacks 90 and caecocolic loop 180 of normal 270 rotation.

Question 21

What history and exam findings would you see in Malrotation of the intestine?

Answer 21

Acute modgut volvulusL presents <1y, SO bilious vomiting, abdominal distension, severe pain.

Chroning midgut volvulus: recurrent abdo pain, malabsorption, Between episodes, normal.

Acute DD obstruction presents with forceful vomiting, abdominal distension, gastric waves, Compression or kinking of duodenum by Ladd bands.

Chronic DD obstruction Presents in infancy with bilious vomiting, intermittent abdominal pain.

Acute obstruction tachycardia, distension, tinkling bowel sounds.

Infarction/necrosisL shock (high HR, pallor, high CRT, low responsiveness( pyrexia and acute peritonitis signs.

Question 22

What investigations would you use for Malrotation of the intestine?

Answer 22

Bloods: high WCC, low Hb if bleeding, UW, Acidosis with high lactate can be present if vessel obstruction present.

AXR: Variable appearance with dilated loops of bowel or gasless abdominal field.

UGI contrast: if patient stable, preformed on all infants with bilious vomiting. Corkscrew appearance with volvulus or DJ flexure to the right of midline with malrotations (normal is on the left)

Question 23

What is the management of Malrotation of the intestine?

Answer 23

Preoperative: correct fluid and electrolyte imbalance, BSAbx, NG tube insertion, ?UGI if stable.

Ladd procedure: reduction of volvulus, division of mesenteric bands, placement of small bowel on right and large bowel on left, and appendicectomy. Transverse supraumbilical incision.

Question 24

What are the complications and prognosis of Malrotation of the intestine?

Answer 24

Strangulaiton and necrosis, perforation, peritonitis, septic shock. Loss of small bowel leading to SBS.

Good with prompt surgical management. Pgx dependson bowel preservation extent.

Question 25

What is Meckel’s diverticulum?

Answer 25

Outpouching of the ileum along the antimesenteric border, containing heterotopic tissue of the stomach (acid secreting parietal cells) pancreas or normal intestinal mucosa.

Question 26

What is the background of Meckel’s diverticulum?

Answer 26

GeneralL partial or incomplete involution of the vitelline duct (omphalomesenteric duct) during embryogenesis. True diverticulum containing all three layers of intestinal wall and its own blood supply.

Rule of 2: 2% population, 2 inches, 2 feet form ileocecal valve, 2% symptomatic, 2 types of ectopic tissue, commonly aged 2 and males 2:1.

Question 27

What history and exam findings would you see in Meckel’s diverticulum?

Answer 27

Most children asymptomatic.

Intermittent painless rectal bleeding due to acid production and its ulcerating effect on the gastrointestinal mucosa downstream.

May have anaemia, intussusception, and may have acute meckels diverticulitis presenting identically to acute appendicitis.

Question 28

What investigations would you use for Meckel’s diverticulum?

Answer 28

Bloods for anaemia, Stool sample for occult blood/MCS

Tc99 scan – binds to gastric mucosa, will show ectopic tissue with pre scan suppression with H2 antagonist. Sensitivity 50-90% so only helpful with positive diagnosis.

Question 29

What is the management of Meckel’s diverticulum?

Answer 29

General: if incidental finding in asymptomatic patient, not recommended to be removed, even if seen on appendicectomy.

Surgical: if symptomatic, ileal resection (not only diverticulotomy as tissue may extend beyond diverticulum). May be done laproscopically through umbilicus.

Question 30

What are the complications and prognosis of Meckel’s diverticulum?

Answer 30

Anastomotic complications (stricture, leak) with surgical intervention. May sometimes contain sarcomas or adenocarcinomas.

Excellent with surgical treatment.

Question 31

What is Mesenteric adenitis?

Answer 31

Mesenteric lymph node inflammation associated with systemic illness and abdominal symptoms

Question 32

What is the background of Mesenteric adenitis?

Answer 32

Acute or chronic. Infection causes enlargement of lymph nodes and possibly odematous mesentery, with suppuration. Involved nodes may be intraabdomina, retroperitoneal, ileocolic vascular distribution common.

Caused by viruses (URTI) bacterial (GAS, Yrs, Hel J, Camp j, Salm Shig)

Common DD for acute appendicitis. With URTI and tonsillitis.

Pathology: MACRO LN enlarged and soft, mesenteric odema. MICRO non specific hyperplasia, necrotic changes if suppurative.

All ages, incidence unknown

Question 33

What history and exam findings would you see in Mesenteric adenitis?

Answer 33

Dx of exclusion. Most common finding at negative appendicectomy. Recent Hx of URTI, corysa, GI infection.

General: may be identical to AA. Cervical lymphadenopathy. High pyrexia, vague abdominal signs.

Specific: peritoneal irritation may be present à guarding on percussion and tenderness

Question 34

What investigations would you use for Mesenteric adenitis?

Answer 34

Bloods: high WCC, ESR, CRP.

USS of RIF: May confirm Dx with visualization of enlarged nodes OR appendix inflamed (non compressive tubular structure in RIF). With MA nodes are in clusters of >5 and are >1cm in diameter.

CT scan: rarely preformed or needed, but excellent positive predictor.

Question 35

What is the management of Mesenteric adenitis?

Answer 35

All should be admitted to be observed for acute appendicitis. MA is self limiting.

Question 36

What are the complications and prognosis of Mesenteric adenitis?

Answer 36

No complications, benign prognosis