LEARN Paediatrics EASY

TETRALOGY OF FALLOT (TOF) 🫀:

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease after the neonatal period. It is a cyanotic congenital heart defect caused by reduced pulmonary blood flow and right-to-left shunting through a VSD.

1. The 4 classical abnormalities

Remember “PROVe”:

1. P – Pulmonary stenosis / RV outflow tract obstruction
* Usually infundibular ± valvar pulmonary stenosis.
* Severity determines the degree of cyanosis.
2. R – Right ventricular hypertrophy
* Secondary to increased RV pressure.
3. O – Overriding aorta
* Aorta is positioned over the VSD and receives blood from both ventricles.
4. V – Ventricular septal defect
* Usually a large, nonrestrictive VSD.

Key pathophysiology

RV outflow obstruction → ↑ RV pressure → blood crosses VSD from RV → LV → overriding aorta → systemic cyanosis

The more severe the pulmonary obstruction, the greater the right-to-left shunt and cyanosis.

⸻

2. Clinical presentation

Mild TOF

If pulmonary stenosis is mild:

* May be acyanotic initially
* Presents with murmur
* May later develop cyanosis

Severe TOF

* Central cyanosis
* Tachypnea
* Poor feeding
* Failure to thrive
* Clubbing in older children
* Exertional dyspnea

Characteristic finding

Squatting after exertion

Older children may squat spontaneously.

Why?

Squatting → ↑ systemic vascular resistance (SVR) → ↓ right-to-left shunting → ↑ pulmonary blood flow → improved oxygenation

⸻

3. Tet spells / hypercyanotic attacks 🚨

A very high-yield MRCPCH topic.

Usually occur during:

* Crying
* Feeding
* Defecation
* Awakening
* Exercise

Clinical features

Sudden:

* Increased cyanosis
* Rapid/deep breathing
* Irritability
* Syncope
* Hypotonia
* Seizures in severe cases

Important: During a severe Tet spell, the murmur may become softer or disappear because pulmonary blood flow becomes extremely low.

⸻

4. Management of a Tet spell

Immediate management

1. Knee–chest position

* Infant: hold with knees flexed against chest.
* Older child: squat/knee-chest.

⬇️

2. Oxygen

⬇️

3. Calm the child

* Minimize crying/stimulation.

⬇️

4. Morphine

* Reduces agitation and hyperventilation.
* Also decreases catecholamine-driven worsening of the obstruction.

⬇️

5. IV fluids

* Improve preload.

⬇️

6. β-blocker

* Propranolol or esmolol may reduce dynamic RVOT obstruction.

⬇️

7. Phenylephrine

* In severe/refractory attacks:
* ↑ SVR → ↓ right-to-left shunting.

Refractory spell

Consider:

* Intubation/ventilation
* Urgent cardiology/cardiothoracic intervention
* Emergency surgical/catheter-based treatment depending on anatomy and local protocol.

⸻

5. Investigations

Pulse oximetry

Shows reduced oxygen saturation in cyanotic disease.

ECG

Typical:

Right ventricular hypertrophy

May show right-axis deviation.

Chest X-ray

Classic:

👢 “Boot-shaped heart” / coeur en sabot

Caused by:

* RV hypertrophy
* Concavity of pulmonary artery segment

Pulmonary vascular markings are often reduced because pulmonary blood flow is decreased.

Echocardiography ⭐

Diagnostic investigation of choice

Shows:

* VSD
* Overriding aorta
* RVOT obstruction
* Pulmonary valve/artery anatomy
* RV hypertrophy
* Associated anomalies

⸻

6. TOF physiology: very important

The severity of cyanosis depends mainly on:

Degree of RV outflow tract obstruction

Mild obstruction

RV → pulmonary artery flow remains relatively good.

→ Less right-to-left shunting
→ Less cyanosis

Severe obstruction

RV cannot eject adequately into pulmonary artery.

→ More blood crosses VSD
→ More blood enters overriding aorta
→ Severe cyanosis

⸻

7. Important associations

TOF is associated with:

* 22q11.2 deletion syndrome
* DiGeorge syndrome
* Alagille syndrome
* Trisomy 21
* Other congenital anomalies

Pulmonary atresia + VSD

This represents an extreme form of TOF physiology and may depend heavily on:

PDA / major aortopulmonary collateral arteries (MAPCAs) for pulmonary blood flow.

⸻

8. Definitive treatment

Surgical repair is definitive treatment.

Usually involves:

* Closure of VSD
* Relief of RV outflow obstruction
* Restoration of adequate RV → pulmonary artery blood flow

Timing depends on anatomy, symptoms, pulmonary blood flow and center-specific strategy.

If severe neonatal TOF

Prostaglandin E1 (PGE1) may be required if pulmonary blood flow is duct-dependent.

⸻

9. Postoperative complications

Important long-term complications include:

* Pulmonary regurgitation
* Residual RVOT obstruction
* RV dilatation
* RV dysfunction
* Arrhythmias
* Ventricular tachycardia
* Sudden cardiac death
* Residual VSD

Patients therefore require lifelong cardiology follow-up.

⸻
HIGH-YIELD POINTS:

Finding TOF
Cyanotic CHD Yes
VSD Large
Pulmonary stenosis Present
Aorta Overriding
RV Hypertrophy
Pulmonary blood flow Reduced
CXR Boot-shaped heart
ECG RVH
Tet spell Hypercyanotic episode
Spell position Knee-chest/squatting
Definitive treatment Surgical repair
Important genetic association 22q11.2 deletion

🧠 One-line memory

TOF = VSD + Overriding Aorta + Pulmonary stenosis/RVOT obstruction + RVH → right-to-left shunt → cyanosis.

ACUTE MANAGEMENT OF ASTHMA IN CHILDREN:

Emergency / acute exacerbation — exam-oriented approach

This is based primarily on the 2026 GINA strategy, with emphasis on practical pediatric emergency management.

⸻

1. FIRST: RAPID ASSESSMENT

ABC + severity assessment

A — Airway

* Patent?
* Ability to speak/cry
* Consider foreign body/anaphylaxis if atypical presentation

B — Breathing

* Respiratory rate
* Work of breathing
* Accessory muscle use
* Wheeze
* Air entry
* Silent chest = very severe/life-threatening
* SpO₂
* PEF/FEV₁ if child is old/cooperative enough

C — Circulation

* HR
* BP
* Perfusion
* Pulsus paradoxus is not routinely required

Red flags for life-threatening asthma

🚨 Immediate senior/PICU involvement

* Altered consciousness, drowsiness or confusion
* Exhaustion
* Silent chest
* Severe hypoxemia
* Cyanosis
* Poor respiratory effort
* Bradycardia
* Poor air entry despite severe distress
* Rising CO₂ / respiratory acidosis
* Failure to respond to repeated bronchodilator therapy

GINA recommends immediate transfer to acute care for severe exacerbations and intensive care when the child is drowsy/confused or has a silent chest.

⸻

2. OXYGEN

Give controlled oxygen if hypoxemic.

Target approximately:

SpO₂ 94–98% in children

Avoid unnecessary excessive oxygen; titrate according to saturation.

⸻

3. FIRST-LINE BRONCHODILATOR — SALBUTAMOL

Preferred route

For most children who can cooperate:

pMDI + spacer

This is at least as effective as nebulization in many children and is faster to administer.

Salbutamol pMDI

4–10 puffs via spacer, one puff at a time with several breaths after each puff.

Repeat approximately every 20 minutes for the first hour, according to clinical response/severity.

For severe attacks, nebulized therapy may be preferable.

⸻

Nebulized salbutamol

Typical pediatric emergency dosing:

≤5 years

2.5 mg nebulized

>5 years

2.5–5 mg nebulized

May be repeated frequently during the first hour depending on severity and response.

⚠️ Important: GINA previously identified a dosing error in its 2025 report where nebulized salbutamol for children ≤5 years was incorrectly printed as 0.25 mg; the corrected dose is 2.5 mg.

For severe/life-threatening asthma, continuous nebulized salbutamol can be considered in an appropriate monitored setting.

⸻

4. ADD IPRAΤROPIUM IN MODERATE–SEVERE ASTHMA

Add ipratropium bromide early when the attack is moderate/severe or poorly responsive to initial salbutamol.

Typical nebulized dose:

FOREIGN BODY INGESTION IN CHILDREN :

Foreign body ingestion is common in children, particularly 6 months–5 years. Management depends on the type of object, location, time since ingestion, symptoms, and child’s age/size.

🚨 FIRST PRIORITY: Is the child unstable?

Assess ABCDE and look for:

* Respiratory distress or stridor
* Choking
* Cyanosis
* Drooling / inability to swallow saliva
* Severe neck, chest, or abdominal pain
* Persistent vomiting
* Signs of perforation or peritonitis

➡️ Unstable child = emergency management and urgent specialist intervention.

⸻

1️⃣ Important types of foreign bodies

🪙 Coins

Usually low risk but can become impacted in the oesophagus.

🔋 Button batteries — EXTREME EMERGENCY

An oesophageal button battery can cause severe tissue injury rapidly.

➡️ Immediate removal if located in the oesophagus.

🧲 Magnets

⚠️ Multiple magnets or a magnet plus another metallic object can attract across bowel loops.

Potential complications:

* Pressure necrosis
* Bowel perforation
* Fistula
* Volvulus
* Obstruction

➡️ Requires urgent specialist assessment.

🦴 Sharp/pointed objects

Examples:

* Needles
* Pins
* Fish bones
* Toothpicks
* Sharp metal/plastic pieces

Risk:

* Perforation
* Migration
* Abscess

➡️ Location determines urgency; objects in the oesophagus generally require urgent removal.

🍇 Food bolus

Consider underlying oesophageal pathology if recurrent, such as:

* Eosinophilic oesophagitis
* Oesophageal stricture
* Achalasia

⸻

2️⃣ INVESTIGATIONS

📷 Plain X-ray

Usually obtain appropriate radiographs of:

Neck + chest + abdomen

Radiographs can identify many radiopaque objects:

* Coins
* Batteries
* Magnets
* Metal objects

⚠️ Remember that many objects are radiolucent, including:

* Plastic
* Wood
* Some glass
* Aluminium

A normal X-ray does not always exclude foreign body ingestion.

⸻

3️⃣ KEY MANAGEMENT BY OBJECT

Object Oesophagus Stomach / Intestine
🪙 Coin Urgent if symptomatic; generally remove within 24 h Usually observe
🔋 Button battery 🚨 Immediate emergency removal Depends on age, battery size, symptoms & progression—urgent specialist guidance
🧲 Multiple magnets Urgent removal Urgent assessment and close monitoring/intervention
📍 Sharp object Urgent removal Often requires urgent assessment and monitoring
🧸 Small blunt object Remove if symptomatic/impacted Usually observation

⸻

4️⃣ SIZE MATTERS

Large or long objects are less likely to pass through the pylorus or intestinal tract.

Particularly concerning:

* Large-diameter objects
* Long objects
* Objects with irregular shapes

Management should consider the child’s age and body size, as well as object dimensions.

⸻

5️⃣ FOREIGN BODY IN THE OESOPHAGUS

Symptomatic

Symptoms include:

* Drooling
* Dysphagia
* Respiratory symptoms
* Inability to handle secretions

➡️ Urgent endoscopic removal.

Asymptomatic

Management depends on the object, but many oesophageal foreign bodies require removal rather than prolonged observation.

⚠️ Button battery = immediate removal regardless of symptoms.

⸻

6️⃣ FOREIGN BODY IN THE STOMACH

Management depends on object type.

Usually observation

✔ Small blunt objects
✔ Single coin
✔ Object progressing normally
✔ Asymptomatic child

Consider removal/urgent intervention

❗ Battery depending on circumstances
❗ Magnets
❗ Sharp object
❗ Large or long object
❗ Persistent object
❗ Symptoms develop

⸻

7️⃣ IMPORTANT COMPLICATIONS

Watch for:

* Oesophageal ulceration
* Perforation
* Mediastinitis
* Bowel obstruction
* Intestinal perforation
* Peritonitis
* Fistula formation
* GI bleeding
* Infection

⸻

🧠 PRACTICAL PAEDIATRIC ALGORITHM

Child with suspected foreign body ingestion

⬇️

1️⃣ ABCDE + assess symptoms

🚨 Airway compromise / severe symptoms?

➡️ Emergency management

⬇️

2️⃣ Identify the object

Ask:

* What was swallowed?
* Coin, battery, magnet, sharp object?
* How many objects?
* When was it swallowed?

⬇️

3️⃣ X-ray if radiopaque object suspected

Neck + chest + abdomen

⬇️

4️⃣ Identify location

Oesophagus → Stomach → Small intestine

⬇️

5️⃣ Management based on OBJECT + LOCATION + SYMPTOMS

⭐ HIGH-YIELD RULE

BUTTON BATTERY + OESOPHAGUS = IMMEDIATE EMERGENCY REMOVAL

MULTIPLE MAGNETS = HIGH RISK, URGENT SPECIALIST ASSESSMENT

SHARP OBJECT IN OESOPHAGUS = URGENT REMOVAL

SMALL BLUNT OBJECT BEYOND OESOPHAGUS + ASYMPTOMATIC CHILD = USUALLY OBSERVATION

COIN INGESTION IN CHILDREN:

Coin ingestion is one of the most common foreign-body ingestions in children, especially between 6 months and 5 years. Management depends primarily on where the coin is located and whether the child is symptomatic.

1. Clinical presentation

Many children are asymptomatic, especially if the coin has reached the stomach.

Possible symptoms of an oesophageal coin include:

* Drooling
* Dysphagia or refusal to eat
* Vomiting
* Gagging
* Neck or chest pain
* Coughing or wheezing
* Stridor
* Respiratory distress

⚠️ Complete oesophageal obstruction may cause inability to swallow saliva and significant drooling.

⸻

2. Initial assessment

ABCDE approach

🚨 Assess immediately for:

* Airway compromise
* Stridor
* Respiratory distress
* Cyanosis
* Inability to handle secretions
* Severe chest/neck pain

If the child has significant respiratory distress or complete obstruction, this is an emergency.

⸻

3. Investigation

X-ray

Obtain radiographs covering:

Neck + chest + abdomen

Usually:

* AP view
* Lateral view if oesophageal location needs confirmation

Important X-ray finding

🪙 Coin in oesophagus → appears round (“en face”) on AP X-ray

This is because the coin usually lies in the coronal plane.

⸻

🚨 Always differentiate a COIN from a BUTTON BATTERY

This is extremely important.

Coin

* Single uniform circular density

Button battery

* Double rim / halo sign on AP X-ray
* Step-off sign on lateral X-ray

⚠️ A suspected button battery in the oesophagus is an immediate emergency and requires urgent removal.

⸻

4. Management according to location

🟥 A. Coin in the OESOPHAGUS

Symptomatic child

Examples:

* Drooling
* Unable to swallow saliva
* Respiratory symptoms
* Significant pain

➡️ Urgent endoscopic removal

⸻

Asymptomatic child

If the child is comfortable and can handle secretions:

➡️ Usually endoscopic removal within 24 hours.

Some coins may pass spontaneously into the stomach, particularly if located in the distal oesophagus, but persistent oesophageal foreign bodies should not simply be left indefinitely.

⸻

🟨 B. Coin in the STOMACH

If the child is:

* Asymptomatic
* No underlying GI abnormality
* Coin is an ordinary, low-risk coin

➡️ Usually expectant management.

Most coins pass spontaneously through the gastrointestinal tract.

Parents should monitor for:

* Abdominal pain
* Persistent vomiting
* GI bleeding
* Fever
* Signs of bowel obstruction

Follow-up imaging may be used to confirm progression when clinically indicated.

⸻

🟩 C. Coin beyond the STOMACH

If the child remains asymptomatic:

➡️ Observation is generally appropriate.

The coin usually passes in stool.

Consider further assessment if:

* Symptoms develop
* The coin fails to progress
* There is known intestinal narrowing or previous GI surgery
* Multiple objects were ingested

⸻

5. Important contraindications / high-risk situations

Be more cautious in children with:

* Previous oesophageal surgery
* Oesophageal stricture
* Achalasia
* Eosinophilic oesophagitis
* Congenital GI abnormalities
* Previous GI surgery
* Known intestinal strictures

These children may require earlier specialist involvement.

⸻

📌 Practical management algorithm

Child swallowed a suspected coin

⬇️

1️⃣ Check airway and symptoms

Respiratory distress / unable to swallow secretions?

➡️ 🚨 Emergency assessment and urgent removal

⬇️

2️⃣ X-ray: neck + chest + abdomen

⬇️

3️⃣ Confirm: COIN or BUTTON BATTERY?

Button battery suspected?

➡️ 🚨 Immediate emergency removal if in oesophagus

⬇️

4️⃣ Location of coin

Location Management
Oesophagus + symptomatic Urgent endoscopic removal
Oesophagus + asymptomatic Removal generally within 24 h
Stomach + asymptomatic Observation
Intestine + asymptomatic Observation and clinical follow-up
Any location + obstruction/perforation symptoms Urgent surgical/GI assessment

⸻

⭐ Key paediatric exam points

🔹 First rule: Always exclude a button battery.

🔹 A coin in the oesophagus usually appears en face on AP X-ray.

🔹 Symptomatic oesophageal coin = urgent removal.

🔹 Asymptomatic oesophageal coin should generally be removed within 24 hours.

🔹 Coins in the stomach usually pass spontaneously.

🔹 Development of abdominal pain, vomiting, bleeding, fever, or obstruction requires reassessment.

USHER SYNDROME:

Usher syndrome is a rare inherited disorder characterized primarily by:

1. 👂 Sensorineural hearing loss
2. 👁️ Retinitis pigmentosa (RP) → progressive visual impairment
3. ⚖️ Vestibular dysfunction in some types → balance and delayed walking

It is the most common genetic cause of combined deafness and blindness.

⸻

🧬 Genetics

Usually autosomal recessive.

A child generally inherits one pathogenic variant from each carrier parent.

Several genes can cause Usher syndrome, including:

* MYO7A
* USH1C
* CDH23
* PCDH15
* USH2A
* CLRN1

⸻

TYPES OF USHER SYNDROME

Feature Type 1 (USH1) Type 2 (USH2) Type 3 (USH3)
Hearing loss Severe–profound congenital Mild–severe congenital Progressive
Retinitis pigmentosa Early childhood Usually adolescence Variable
Vestibular function Absent/severely impaired Normal Variable/progressive
Walking Delayed Normal age Usually normal initially
Hearing progression Usually stable Usually stable Progressive

⸻

🔴 USHER SYNDROME TYPE 1

Typical presentation

A child may have:

* Profound congenital sensorineural hearing loss
* Very poor or absent vestibular function
* Delayed sitting and walking
* Retinitis pigmentosa developing during childhood

Important clinical clue

Congenital profound deafness + delayed walking because of vestibular dysfunction = think Usher type 1.

⸻

🟠 USHER SYNDROME TYPE 2

The most common form in many populations.

Features

* Congenital bilateral sensorineural hearing loss
* Vestibular function is generally normal
* Normal motor milestones
* Retinitis pigmentosa develops later, often during adolescence

Important clue

Child with congenital hearing loss but normal walking and balance, followed later by night blindness → consider Usher type 2.

⸻

🟡 USHER SYNDROME TYPE 3

Less common.

Features

* Hearing may initially be normal or mildly impaired
* Progressive hearing loss
* Progressive retinitis pigmentosa
* Vestibular dysfunction may occur

The age of onset and severity are variable.

⸻

👁️ RETINITIS PIGMENTOSA

Retinitis pigmentosa causes progressive degeneration of the retina.

Typical sequence

🌙 Night blindness (nyctalopia)
↓
👀 Difficulty seeing in dim light
↓
↔️ Progressive peripheral visual field loss
↓
🔭 Tunnel vision
↓
Central vision may eventually become affected

Fundoscopy may show

* Bone-spicule pigmentation
* Attenuated retinal vessels
* Waxy pallor of the optic disc

⸻

👂 HEARING PROBLEMS

The hearing loss is sensorineural.

This may lead to:

* Delayed speech and language development
* Difficulty with communication
* Educational challenges

Early identification is important because interventions such as:

* Hearing aids
* Cochlear implantation (depending on severity)
* Speech and language therapy

can significantly improve communication outcomes.

⸻

⚖️ VESTIBULAR DYSFUNCTION

Particularly important in Usher type 1.

The vestibular system is responsible for balance and spatial orientation.

Clinical signs in infants

* Delayed sitting
* Delayed independent walking
* Frequent imbalance
* Difficulty with activities requiring balance

Important paediatric clue

A deaf child who walks late should be assessed for vestibular dysfunction and Usher syndrome.

⸻

🩺 DIAGNOSIS

Diagnosis is based on a combination of:

1️⃣ Audiological assessment

* Newborn hearing screening
* Pure-tone audiometry
* Auditory brainstem response (ABR)

2️⃣ Ophthalmological assessment

* Fundoscopy
* Visual field testing
* Electroretinography (ERG)
* Optical coherence tomography (OCT)

ERG can detect retinal dysfunction, sometimes before significant symptoms appear.

3️⃣ Vestibular assessment

Especially when Type 1 is suspected.

4️⃣ Genetic testing

A multigene panel or comprehensive genomic testing can confirm the molecular diagnosis.

⸻

🧠 IMPORTANT DIFFERENTIAL DIAGNOSES

Combined hearing and visual impairment may also occur in:

* Alström syndrome
* Bardet–Biedl syndrome
* Mitochondrial disorders
* Congenital infections (e.g., CMV)
* Other syndromic retinal dystrophies

The combination of sensorineural hearing loss + retinitis pigmentosa ± vestibular dysfunction strongly suggests Usher syndrome.

⸻

MANAGEMENT

There is currently no universal curative treatment, so management is multidisciplinary.

👂 Hearing

* Hearing aids
* Cochlear implant evaluation
* Speech and language therapy
* Sign language or other communication support

👁️ Vision

* Regular ophthalmology follow-up
* Low-vision aids
* Mobility training
* Educational support

⚖️ Balance

* Physiotherapy
* Vestibular rehabilitation

🧬 Genetics

* Genetic counselling
* Carrier counselling for family members
* Discussion of reproductive options where appropriate

⸻

⭐ EXAM SUMMARY

Usher syndrome =

Sensorineural hearing loss + Retinitis pigmentosa ± Vestibular dysfunction

Quick comparison:

🔴 Type 1:
Congenital profound deafness + absent vestibular function + early RP

🟠 Type 2:
Congenital hearing loss + normal vestibular function + later RP

🟡 Type 3:
Progressive hearing loss + progressive RP ± vestibular dysfunction

High-yield paediatric pearl 💡

Congenital deafness + delayed walking → think Usher syndrome Type 1.