PassMed Gastro Flashcards
Rotavirus Vaccine: what condition, what type of vaccine, when taken, time when you can’t take it no more
Rotavirus causes gastroenteritis (more common in developed countries in winter and early spring)
Rotavirus is a major public health problem, accounting for significant morbidity and hospital admissions in the developed world and childhood mortality in the developing world.
A vaccine was introduced into the NHS immunisation programme in 2013. The key points to remember as as follows:
- it is an oral, live attenuated vaccine
- 2 doses are required, the first at 2 months, the second at 3 months
- the first dose should not be given after 14 weeks + 6 days and the second dose cannot be given after 23 weeks + 6 days due to a theoretical risk of intussusception
Other points
- the vaccine is around 85-90% effective and is predicted to decrease hospitalisation by 70%
- offers long-term protection against rotavirus
Pyloric stenosis
A 4-month-old baby is brought to the Emergency Department with vomiting for the past 3 days. His mother describes the vomiting as projectile that occurs after every feed and is not settling. On examination the baby appears well. Heart rate is 140bpm, respiratory rate is 36/min, blood pressure is 90/60mmHg, capillary refill is 3 seconds and mucous membranes are slightly dry. He is afebrile
Pyloric stenosis typically presents in the second to fourth weeks of life with vomiting, although rarely may present later at up to four months. It is caused by hypertrophy of the circular muscles of the pylorus. Congenital.
Epidemiology
- incidence of 4 per 1,000 live births
- 4 times more common in males
- 10-15% of infants have a positive family history
- first-borns are more commonly affected
Features
- ‘projectile’ vomiting, typically 30 minutes after a feed = non-billous, increased frequency and forcefulness
- constipation and dehydration may also be present → loss of interest in feeding → weight loss
- a palpable ‘olive’ mass may be present in the upper abdomen
- hypochloraemic, hypokalaemic alkalosis due to persistent vomiting
Diagnosis
- Most commonly made by ultrasound (pylori muscle thickness >4mm, pyloric canal length >17mm) – sensitivity 97%
- U+Es for alkalosis
- olive mass
Complications:
- failure to thrive, oesophagitis, pulmonary aspiration, sandifer syndrome
Pyloric stenosis mx
Most common cause of diarrhoea and vomiting in children
Rotavirus
diarrhoea and vomiting timeline
clinical features dehydration and shock
- diarrhoea usually lasts for 5-7 days and stops within 2 weeks
- vomiting usually lasts for 1-2 days and stops within 3 days
Early (compensated) vs Late (decompensated) shock
What children are at risk of dehydration?
- children younger than 1 year, especially those younger than 6 months
- infants who were of low birth weight
- children who have passed six or more diarrhoeal stools in the past 24 hours
- children who have vomited three times or more in the past 24 hours
- children who have not been offered or have not been able to tolerate supplementary fluids before presentation
- infants who have stopped breastfeeding during the illness
- children with signs of malnutrition
Features suggestive of hypernatraemic dehydration
- jittery movements
- increased muscle tone
- hyperreflexia
- convulsions
- drowsiness or coma
When should you do a stool culture?
- you suspect septicaemia or
- there is blood and/or mucus in the stool or
- the child is immunocompromised
- the child has recently been abroad or
- the diarrhoea has not improved by day 7 or
- you are uncertain about the diagnosis of gastroenteritis
Management of no evidence of dehydration, and suspected dehydration
The most accurate measure of dehydration is the degree of weight loss during the illness:
- Clinical dehydration: ≥5%
- Shock: >10%
For children with no evidence of dehydration
- continue breastfeeding and other milk feeds
- encourage fluid intake
- discourage fruit juices and carbonated drinks
*50ml/kg every 4 hours ORS
Fluid resuscitation
*10ml/kg bolus of 0.9% saline
Routine maintenance fluid
NOTE: males rarely need more than 2500mL and females 2000mL per day
Measure electrolytes and glucose when starting IV fluids and at least every 24 hours there after
Hypernatraemic dehydration mx
- Oral rehydration solution should be used to rehydrate
- If IV fluids are required, a rapid reduction in plasma sodium concentration and osmolality will lead to a shift of water into the cerebral cells and may result in seizures and cerebral oedema
- So, the reduction in plasma sodium should be slow
- The fluid deficit should be replaced over at least 48 hours and the plasma sodium should be measured regularly
How do we mx shock? resus/bolus, replacement, maintenance
Use glucose-free crystalloids that contain sodium in the range 131–154 mmol/litre, with a BOLUS of 20 ml/kg over less than 10 minutes for children and young people, and 10–20 ml/kg over less than 10 minutes for term neonates.
Fluid RESUS/BOLUS: 10ml/kg over 10 minutes
Fluid REPLACEMENT: 100ml/kg over 24 hours
Fluid MAINTENANCE: 100ml/kg for first 10kg, 50ml/kg for second 10kg, 20ml/kg for every kg thereafter.
Correction of dehydration
Percentage dehydration × weight (kg) × 10
Given over 48hours
Biliary Atresia: signs and symptoms, types, investigations, complications, prognosis
Destruction or absence of extrahepatic biliary tree and intrahepatic biliary ducts (inflammation and resulting fibrosis ) → leads to biliary obstruction, chronic liver failure and death (needs urgent surgical intervention
- Failure to thrive (↓ absorption of long-chain fats and catabolic state)
- Mild jaundice (conjugated) >14d
- Pale urine, dark stools (after normal
- meconium)
- Hepatomegaly ± splenomegaly and portal HTN
- cardiac murmurs if associated cardiac abnormalities present
Types:
- Type 1: The proximal ducts are patent, however, the common duct is obliterated
- Type 2: There is atresia of the cystic duct and cystic structures are found in the porta hepatis
- Type 3: There is atresia of the left and right ducts to the level of the porta hepatis, this occurs in >90% of cases of biliary atresia
Investigations:
- Serum bilirubin including differentiation into conjugated and total bilirubin: Total bilirubin may be normal, whereas conjugated bilirubin is abnormally high (DIAGNOSTIC)
- Liver function tests (LFTs) including serum bile acids and aminotransferases are usually raised but cannot differentiate between biliary atresia and other causes of neonatal cholestasis
- Serum alpha 1-antitrypsin: Deficiency may be a cause of neonatal cholestasis
- Sweat chloride test: Cystic fibrosis often involves the biliary tract
- Ultrasound of the biliary tree and liver: May show distension and tract abnormalities
- Percutaneous liver biopsy with intraoperative cholangioscopy
Complications: Even when successful, few will still progress to cirrhosis and portal HTN → need liver transplant
- Unsuccessful anastomosis formation
- Progressive liver disease
- Cirrhosis with eventual hepatocellular carcinoma
Prognosis:
- Prognosis is good if surgery is successful
- In cases where surgery fails, liver transplantation may be required in the first two years of life
Biliary atresia mx
Malrotation clinical features
- Predisposition to volvulus if mesentery is not fixed to duodenal flexure or ileocaecal region leading to shortened base
- Ladd bands may cross duodenum, contributing to obstruction
- Abnormality of bowel that happens when baby is in the womb
- May be asymptomatic but will re-present with obstruction once the duodenum twists ± compromised blood supply → no stools, cramps, crying and pulling legs up
Usually 3-7 days after birth, volvulus with compromised circulation may result in peritoneal signs and haemodynamic instability
- Classically first few days of life – obstruction with bilious vomiting
- Can present at any age with volvulus
Look for bilious vomiting + signs of dehydration
Malrotation Ix
Upper GI contrast study may show DJ flexure is more medially placed, USS may show abnormal orientation of SMA and SMV
Can use USS
How do we treat malrotation?
What is congenital diaphragmatic hernia, and what are it’s features? how do we investigate for it + most common type of hernia in this case
- 8 weeks of pregnancy – diaphragm does not form correctly
- Part of intestine moves through chest area – stops lungs from developing properly (Bochdalek hernia)
- The most common type of CDH is a left-sided posterolateral Bochdalek hernia which accounts for around 85% of cases. Only around 50% of newborns with CDH survive despite modern medical intervention.
- Usually L sided
Ix = Diagnosed on routine antenatal US or after
Features:
- Delivery with respiratory issues (cyanosis; increased RR, increased HR, chest asymmetry, bowel sounds in chest, absent breath sounds on one side, decreased air entry)
- pulmonary hypoplasia
- hypertension
- displaced apex beat
congenital diaphragmatic hernia mx
Initial management is through the insertion of a nasogastric tube with the aim of keeping air out of the gut. Therefore for cyanosed pt the best way to assist breathing is to intubate and ventilate. The child needs definitive management in the form of surgical repair of the diaphragm. = INTUBATE AND VENTILATE
BIPAP and CPAP are airway adjuncts used when the problem is keeping the airway open, such as COPD or respiratory distress syndrome.
Facemask ventilation and nasal cannulae would only increase the risk of air entering the gut, the infant needs an artificial airway to ensure they are able to receive oxygen.
A 28-year-old primiparous woman who is 20 weeks pregnant presents after her foetal anomaly scan. The scan showed polyhydramnios and a midline sac containing bowel. She takes no regular medications and has no significant past medical history. She was planning on having a home birth and would like to know how this will affect her delivery.
What is this? And Mx?
In exomphalos (also known as an omphalocoele) the abdominal contents protrude through the anterior abdominal wall but are covered in an amniotic sac formed by amniotic membrane and peritoneum.
Associations
- Beckwith-Wiedemann syndrome
- Down’s syndrome
- cardiac and kidney malformations
Management
- caesarean section at 37 weeks is indicated to reduce the risk of sac rupture
- a staged repair immediately with completion at 6-12 months may be undertaken as primary closure may be difficult due to lack of space/high intra-abdominal pressure
- if this occurs the sacs is allowed to granulate and epithelialise over the coming weeks/months
- this forms a ‘shell’
- as the infant grows a point will be reached when the sac contents can fit within the abdominal cavity. At this point the shell will be removed and the abdomen closed
Gastroschisis
Gastroschisis describes a congenital defect in the anterior abdominal wall just lateral to the umbilical cord.
Gastroschisis is associated with socioeconomic deprivation (maternal age <20, maternal alcohol/tobacco use)
Management
- vaginal delivery may be attempted
- newborns should go to theatre as soon as possible after delivery, e.g. within 4 hours
Umbilical hernia mx and associations
Umbilical hernia are relatively common in children and may be found during the newborn exam. Usually no treatment is required as they typically resolve by 3 years of age
Associations
- Afro-Caribbean infants
- Down’s syndrome
- mucopolysaccharide storage diseases
Inguinal hernia
nguinal hernias are a common disorder in children. They are commoner in males as the testis migrates from its location on the posterior abdominal wall, down through the inguinal canal. A patent processus vaginalis may persist and be the site of subsequent hernia development.
Children presenting in the first few months of life are at the highest risk of strangulation and the hernia should be repaired urgently. Children over 1 year of age are at lower risk and surgery may be performed electively. For paediatric hernias a herniotomy without implantation of mesh is sufficient. Most cases are performed as day cases, neonates and premature infants are kept in hospital overnight as there is a recognised increased risk of post operative apnoea.
Crohn’s features
- presentation may be non-specific symptoms such as weight loss and lethargy
- diarrhoea: the most prominent symptom in adults. Crohn’s colitis may cause bloody diarrhoea
- abdominal pain: the most prominent symptom in children
- perianal disease: e.g. Skin tags or ulcers
- extra-intestinal features are more common in patients with colitis or perianal disease
What would you see in radiology of CD
Small bowel enema
- high sensitivity and specificity for examination of the terminal ileum
- strictures: ‘Kantor’s string sign’
- proximal bowel dilation
- ‘rose thorn’ ulcers
- fistulae
CD Mx
Stop smoke
monitor ferritin, B12, calcium, vit D, anaemia
educate on flare ups
impact of sc
risk: osteoporosis
inducing remission = corticosteroid mono therapy, budesonide, aminosalicylates (mesalazine), immsupp (azathioprine, methotrexate), biologics (infliximab, adalimumab)
respective surgery if terminal ileum only
maintaining remission = azathioprine or methotrexate
TPMT activity
IBD key differences
Acute abdominal pain in children Ddx
Intussusception summary
Ix and Mx for intussusception
Ix = USS → target-like mass
Mx:
- A→E
- IV fluids and NG tube aspiration
- reduction by rectal air insufflation by radiologist (with fluoroscopy guidance, CI peritonitis) → 75% success rate, 25% require operation
Clinically stable with no CI to contrast enema reduction:
- fluid resuscitation
- contrast enema (air or contrast liquid e.g. Barium or Gastrograffin)
- CI = peritonitis, perforation, hypovolaemia shock
- Broad-spectrum abx = clindamycin + gentamycin OR tazocin OR cefoxitin + vancomycin
- 2nd line = surgical reduction w/ broad-spectrum abx
If recurrent = consider investigating for pathology (e.g. Meckel’s diverticulum)
Meconium aspiration mx
MSAD but no hx of GBS/RFs → observation
RFs or lab findings suggestive of infection → consider abx
- IV ampicillin AND gentamicin
- oxygen therapy and NIV (e.g. CPAP)
- IV fluids
- monitor ABG, O2 sat, FBC, CRP, blood culture, cardiac echo (in severe MAS)
How do we manage gastroenteritis?
GI disorder summary
Constipation criteria in children
Idiopathic constipation vs ‘red flag’ suggesting underlying disorder
Management of constipation in children
Exclude red flag symptoms, reassure underlying causes have been excluded
Laxatives = may have to be taken for several months. OSMOTIC then STIMULANT
- bulk forming = fybogel, methylcellulose
- osmotic = lactulose, movicol
- stimulant = bisacodyl, Senna, sodium picosulphate
- stool-softener = arches oil, decussate sodium
Check for faecal impaction: if present, recommend disimpaction regimen
- osmotic laxative escalating dose over 2 weeks
- with dietary/lifestyle modification
- if unresponsive → add Senna → manual evacuation
Maintenance laxative treatment if impact not present/treated
- osmotic laxative
- with dietary lifestyle modification
- reduce dose once normal bowel routine established
Behavioural interventions
- bowel habit diary
- scheduled toileting
- reward systems/star charts = for attempting
- address anxieties going to toilet, stying calm, reassuring
- post = make sure both feet flat on floor
Diet and lifestyle advice
- fluid and fibre intake: more fruits, water, vegetables
- exercise more
Follow up adherence and respond to treatment
Red flags in a constipated child
