Paediatrics JC115: A Critically Ill Child: Childhood Medical Emergencies Flashcards
General examination of a child
- Skin perfusion
- colour
- warmth
- capillary refill <2 - Hydration
- **skin turgor
- mucosa
- **depressed anterior fontanelle (severe dehydration) - Responsiveness
- ***irritability / restlessness / dull
- alertness
- response to stimuli - Respiratory
- **RR (tachypnea, bradypnea)
- **expiratory grunting (indicate respiratory distress)
- obligate nose breathing (<6 months: cannot breathe through mouth)
- ***nasal flaring - Circulation
- compensated shock
—> **tachycardia
—> **skin vasoconstriction / mottling
—> **↓ pulse pressure (↓ CO + ↑ peripheral vascular resistance)
—> **long capillary refill (>4s)
—> ***BP may be normal (do not rely on BP) - Seizure
- tonic-clonic convulsion may not be seen —> convulsion may simply present as change in alertness, abnormal vital signs, abnormal muscle activity (e.g. blinking, chewing, cycling movements of limbs) - Fever
- always ominous (worrying)
- hypothermia: may indicate severe sepsis (e.g. immunocompromised)
Respiratory principles in children
- CNS receptors / effectors
- **biphasic response (tachypnea, bradypnea) in hypoxia in neonates
- **Respiratory decompensation when exposed to hypoxia (hyperventilate only for short time —> decompensation) - Chest stability / strength
- **cartilaginous thorax, more **horizontal ribs + diaphragm
- major source of ventilation: ***diaphragmatic activity —> abdominal distension, painful procedures on abdomen —> affect diaphragmatic movement —> respiratory decompensation - Airways: ↑ alveoli with age, higher airway resistance
- ***Less respiratory reserve
- Airway obstruction common
- respiratory decompensation common when compared to adult - Allow position of comfort / sniffing position (sit up + lean forward) if respiratory distress (if no C-spine injury)
- High levels of supplemental oxygen
Cardiovascular principles in children
- ***Small absolute blood volume
- although volume to weight is higher in children (80-90 ml/kg) (adult: 60 ml/kg)
- 3kg: 180ml
- beware of blood loss challenges - Cardiac output dependent on ***rate due to low stroke volume
- heart muscle more stiff in infancy —> ↑ CO by ↑ HR (rather than ↑ contractility) - ***Bradycardia ominous
- Response to fluids after 8 weeks similar to adult, CVP less accurate ∵ short neck
- ***Reactive pulmonary vasculature
- easily go into pulmonary hypertension —> easy to develop severe hypoxia - Variable catecholamine response (not as ideal as in adult)
- require ***higher dose of catecholamine to ↑ contractility
- require close monitoring
Non-hypovolaemic shock
Initially treat with titrated fluid to 40 ml/kg to test response
Possible causes:
Obstructive shock
1. **Pneumothorax
2. **Pericardial effusion, Myocardial dysfunction
3. Pulmonary artery hypertension, Coarctation of aorta
Distributive shock
1. Intestinal ischaemia
2. **Sepsis
3. Adrenal insufficiency (*Addisonian crisis)
Metabolic / Thermal principles
- ***Greater insensible water loss
- ∵ greater SA to volume ratio - ***Hypoglycaemia more common
- require higher glucose infusion - Appropriate urine output for age
- neonate 2 ml/kg/hour
- child 1 ml/kg/hour - ***Greater heat loss
- ∵ greater SA to volume ratio (esp. on the head)
- easier hypothermia - Hypo / Hypernatraemia
- Hypocalcaemia in newborns
Paediatric Early Warning Score (PEWS)
3 parameters:
1. **Behaviour
2. **Cardiovascular
3. ***Respiratory
NOT indicated for ICU need, only for monitoring / assessment use
0-4 (stable): continue 4-hourly assessment
5-6: more frequent assessment, doctor notification needed
>=7: critical frequent assessment q30min, immediate doctor notification
Summary of physiological differences
- Variations in maturation of organ systems + physiologic responses
- Child is NOT miniature adults
- Physiological condition ~ to adult by 8-12 years, but NOT mentally (higher demand for better care)
- **Body size + **SA constraints (e.g. IV line, intubation more difficult)
- **Vascular responses + **Volume considerations
- Small margin for error (for smaller child)
- Early consultation
Paediatric emergency
Sudden unexpected cessation of functional **ventilation + **circulation in a person otherwise not expected to die
- ***Respiratory arrest more common than Cardiac arrest in paediatrics
2 types
1. IHCA (In-hospital cardiac arrest)
2. OHCA (Out-hospital cardiac arrest)
- recognition + activation of **ERS (emergency response system)
- immediate high quality **CPR
- rapid **defibrillation
- basic + advanced EMS, **rapid transfer to hospital (for OHCA)
- **advanced life support + **post-arrest care + ICU
Cardiac Pulmonary Resuscitation (CPR)
3 phases: Basic CPR —> Advanced life support —> Prolonged life support / Post-arrest care
Phase 1: Basic CPR
- aim at **maintaining oxygenation + circulation —> ABC
- **2 hand approach: compression site: thumb around chest at mid-sternal area
- 2 finger approach: (not very effective)
- 1 hand approach: for older child
Phase 2: Advanced life support
- aim at restoration of **Spontaneous circulation
—> **Drugs (e.g. adrenaline)
—> ECG (for abnormal rhythms)
—> ***Defibrillation
Phase 3: Prolonged life support (after successful resuscitation)
- Management of **multiple organ failure
- Esp. on the aspect of **Brain resuscitation
- Gauging: identify cause of arrest + treat accordingly
- Human mentation: Cerebral resuscitation
- ***ICU support
Priority should be given to ABC establishment
- good team work essential
- good communication + close loop practice (whenever someone order a treatment —> someone then follow + feedback)
- good documentation of the events
International Liaison Committee on Resuscitation (ILCOR)
Major concept change in 2015:
- **ABC —> CAB
- Time difference: first ventilation after 30 compressions ~20s (not much difference)
- Emphasis on **Circulation is most important (esp. for adults)
- **Rate + Depth of compression + **Minimal interruption
- Better choice for lay rescuer (∵ opening airway + rescue breaths are more difficult than compression)
- Controversial in paediatrics (∵ respiratory arrest more common than cardiac arrest)
- Simplify BLS by recommend Compression only for untrained lay rescuer
- Dispatcher-assisted CPR
- Transfer to Cardiac arrest centres within short time
***ILCOR: Major changes for Paediatric in 2015
BLS algorithm more similar to adult + simple to achieve rapid + effective bystander CPR
—> more people willing to perform in children
Unwitnessed CA:
- adults: AED first before CPR
- paediatric: ***CPR first (∵ respiratory arrest more common) before AED
Compression:
- Compression depth: **5 cm for adult
- **Chest recoil
- Avoid leaning on chest between compressions
- Provide relatively negative intra-thoracic pressure for better venous return
- **Avoid compression interruption >10s
- **Compression frequency now at 100-120 / min
Airway:
- OHCA: Bag-mask ventilation ~ Advanced airway intervention (e.g. ETT, supraglottic airway)
- IHCA: advanced airway intervention require more training + equipment, no recommendation for / against
Respiratory:
- More monitoring support PALS + newborn: **Continuous end-tidal CO2 —> ensure ETT in correct position, pulse oximetry etc
- Ventilation with advanced airway: **1 breath every 6 seconds
AED:
- Paediatric AED for sudden witness ***cardiac arrest
Drugs:
- Drugs: One dose of Vasopressin of 40iu IV may replace 1st / 2nd dose of adrenaline —> now deleted
—> **Standard-dose epinephrine (X high-dose) (maintain BP by ↑ CO + ↑ PVR)
—> **1mg of epinephrine every 3-5 mins
—> single drug only to maintain simplicity
—> ***administer after defibrillation attempts have failed
Fluid replacement:
- ***More cautious fluid replacement in sepsis esp. in resource-limited settings
Hypothermia therapy:
- Hypothermia therapy for post-arrest did ***NOT have evidence-based benefits —> more cautious use of hypothermia therapy (48 hours), avoid fever (36-37.5oC)
Cardioversion:
- Energy for SVT cardioversion revised to ***1J / kg
Extracorporeal CPR (體外循環):
- **not recommended for routine use in adults —> only when CPR is failing + providers are skilled + patient with readily reversible conditions
- consider eCPR in paediatric patient with **cardiac diagnoses experience ***IHCA in a centre with extracorporeal membrane oxygenation capability
- no evidence for / against OHCA / non-cardiac diagnoses
Organ donation:
- Organ donation should be considered in who do not have ROSC, brain death / withdrawal of care
Dosage of Adrenaline
Recent paediatric studies showed high dose adrenaline ***NOT improve survival rates
- a trend toward worse neurologic outcome
Treatment recommendation:
- **10 ug/kg of epinephrine as the **first + subsequent intravascular doses
- routine use of high-dose (100 ug/kg) IV adrenaline NOT recommended
Neonatal resuscitation
- ***Golden minute (60-second) mark for completing the initial steps + reevaluating + begin ventilation (if required)
- Avoid unnecessary delay in initiation of ventilation
- ***Delayed cord clamping for >30s is reasonable for both term + preterm infants who do not require resuscitation at birth
- Insufficient evidence to recommend an approach to cord clamping for infants who require resuscitation at birth
- Routine use of cord milking for infants born <29 weeks NOT evidence based
- Apart from **SpO2 monitor, additional **ECG monitoring recommended
- ***Certain degree of hypoxia in early neonatal period acceptable
- Suctioning non-vigorous infants with MSL (meconium-stained liquor) approach —> approach is very similar to those without MSL —> but still recommend to have personnel competent with endotracheal intubation around
Route of administration during resuscitation
IV access difficult in children
Intra-osseous route
- for volume bolus + effective delivery of medication
- method: same as bone marrow puncture
- disposable needle available
- site: usually ***anterior tibia ∵ more convenient
Others:
- cuffed ETT can be used in infants / children provided correct tube size + cuff inflation pressure are used
- ***exhaled CO2 detection recommended for confirmation of ETT placement
Problems with paediatric intubation
Anatomical difference:
- Smaller airway + shorter than adult
- Adult larynx more cylindrical + narrowest at vocal cord
Child:
- Funnel shaped + narrowest at **Cricoid cartilage
- More superior + anterior
- tongue + epiglottis relatively large
—> **Non-cuffed ETT commonly used —> can still provide adequate ventilation (vs in adults: if do not use cuffed ETT —> air leakage can be severe)
Laryngeal mask:
- not much studies in children during cardiac arrest
- **higher complication rate in smaller children due to inexperience
- can be helpful in management of **difficult airway (vs ETT)
- treatment recommendation:
—> acceptable initial alternative airway adjunct for providers during paediatric cardiac arrest when tracheal intubation is difficult to achieve
—> use when inexperience in intubation + failed bag-valve mask
***記: BVM —> ETT (non-cuffed) —> if difficult airway —> Laryngeal mask
Quick reference
- allow tailored management for children with different weight / height
Protect ourselves during resuscitation
- PPE
- appropriate PPE (not too much)
- changing disposable gloves - Universal precaution
Emergency conditions in children
- ***Acute epiglottis + Croup
- ***Status epilepticus (SE)
- Status asthmaticus
- Acute poisoning
- Drug overdose
- Cardiovascular emergency
- Anaphylaxis
- Acute epiglottis + Croup
Acute epiglottitis
- Age: 2-6 yo (大個D)
- Onset: Acute (can deteriorate quickly)
- Etiology: **Hib
- Swelling: **Supraglottic
- Symptoms:
—> cough + voice: **Muffled voice (Hot-potato voice)
—> fever: High, usually with **septicaemia, **drooling of saliva
- Appearance: Anxious, **toxic
- Larynx: Tender
- Recurrence: Rare
- Seasonal: None
- X-ray: Thumb sign (very dangerous with medico-legal consequence, patients may develop respiratory decompensation during X-ray)
Croup
- Age: 6 months - 3 years (細個D)
- Onset: **Gradual
- Etiology: **Viral
- Swelling: **Subglottic
- Symptoms:
—> cough + voice: **Hoarse cough (Barking cough)
—> fever: Absent to high
- Appearance: Not acutely ill
- Larynx: Non-tender
- Recurrence: May recur
- Seasonal: Winter
Management of Acute epiglottitis
All suspected cases: Emergency!!!
1. Monitor vital sign
2. O2 supplementation even if patient not cyanosis
3. **NO throat examination —> may stimulate laryngeal spasm —> respiratory arrest
4. Confirmation of Diagnosis made only by direct laryngoscopy in a **safe environment
5. X-ray neck is **dangerous + not necessary for confirmation of Dx
6. do NOT place patient in a horizontal position
7. Transport patient in sitting with experienced doctor ready for intubation
8. Airway equipment
- **Bag + Mask
- **Laryngoscope
- **ETT just 1 size smaller than recommended
- Percutaneous tracheostomy set
Supportive
1. Fluid + Antibiotic
2. Treatment of post-obstructive pulmonary edema
3. Sedation + avoid accidental extubation
4. Care of ETT
5. Adequate humidification
Extubation
1. General condition
2. Fever subsiding
3. Presence of air leak
4. Usually done at 18-24 hours
- Status epilepticus (SE) (+ SpC Paed E-learning: Common Neurological Problems)
3 seizures without awakening / continuous motor seizure activity for >=30 mins (early: <30 mins)
- ↑ cerebral metabolic rate + impaired cerebral perfusion
- Treatment should be given for prolonged seizures of >5 mins
Causes:
1. Febrile status
2. Suboptimal compliance / Sudden withdrawal to AED
3. Meningitis / Encephalitis
4. Trauma (Intracranial haemorrhage)
5. Metabolic disorder / Electrolyte imbalance / IEM
6. Brain tumours
7. Hypertension
8. Idiopathic
Investigations:
1. CT brain (for structural anomaly + rule out ↑ICP)
2. LP for cell count, protein / glucose, C/ST, Enterovirus, HSV PCR, viral titre (for meningitis)
3. NH3, Mg, CaPO4, iCa
4. Urine (for toxicology)
5. Serum for viral titre
6. Viral studies (throat, nasal, rectal swabs for viruses)
Systemic complications of Status epilepticus
- BP
- early: ↑
- late: ↓
- complication: Hypotension - PaO2
- early: ↓
- late: much ↓
- complication: Hypoxia - PaCO2
- early: ↑
- late: much ↓
- complication: ↑ ICP - pH
- early: ↓
- late: much ↓
- complication: Acidosis - Temp
- early: ↑ by 1oC
- late: ↑ by 2oC
- complication: Fever - Autonomic activity
- early: ↑
- late: ↑
- complication: Arrhythmia - Lung fluid
- early: ↑
- late: ↑
- complication: Atelectasis - Cerebral blood flow
- early: 900%
- late: 200%
- complication: Haemorrhage - Cerebral O2 consumption
- early: 300%
- late: 300%
- complication: Ischaemia
Treatment of seizures
Prolonged seizure:
- Duration >5 mins
- Spontaneous cessation unlikely if duration >5-10 mins
- Prolonged seizure more likely progress to SE
- Start treatment (Pre-hospital / AED)
- Supportive: Recovery position, O2 support
Initial / Early convulsive SE:
- Duration 20-30 mins
- Emergency management + Seizure control important
- Better response to early medication
—> >80% within 30 mins
—> 75% within 60 mins
—> 65% within 90 mins
Established convulsive SE:
- Duration 30-60 mins
- Additional Anti-epileptic drugs
- More close monitoring, investigations for underlying causes + complications
Refractory SE:
- Unresponsive to 2 anti-epileptic drugs with duration >60 mins
- Associated with high morbidity + mortality
- Require ICU admission + aggressive control, ventilators + haemodynamic support
Resuscitation + Stabilisation:
1. Basic life support
2. ABC
3. Ensure adequate oxygenation (usually hypoxic in SE)
4. Intubation not usually necessary but be prepared
Pre-hospital treatment:
1. Above
2. Earlier treatment is more likely to stop seizure than those late treatment
3. Single pre-hospital dose of rectal diazepam (0.4 mg/kg, reduced to 0.25 mg/kg for those already on regular anti-convulsants)
Management:
1. Different treatment guidelines + regimen
2. Each department have their own clear management plan —> NO standard protocol
3. Prompt administration of effective drug in adequate doses
4. Monitor complications (e.g. respiratory decompensation, metabolic disturbance, haemodynamic, cerebral edema) + SE
5. Investigations for underlying causes (e.g. brain malformation, infections, poisoning, overdose etc.)
1st line treatment:
0-5 mins:
- Supportive (Recovery position** + O2 supplement)
- Prepare anti-epileptic
6-30 mins:
- 1st line Anti-epileptic medications
1. BDZ:
- Diazepam: Rectal route convenient + effective, IM not effective (∵ poor absorption), IV painful
- Lorazepam: slightly more effective compare with Diazepam
- Midazolam: buccal / intranasal route as effective as rectal
(2. Paraldehyde: no longer available / recommended)
20-60 mins / Refractory status:
- 2nd line treatment if NOT responsive (IV access necessary)
1. Phenytoin (first choice)
2. Phenobarbital
3. Midazolam
4. Levetiracetam (Keppra) (more popular, little SE, less CNS depression + haemodynamic disturbance)
5. Thiopentone / Pentobarbitone infusion (more haemodynamic disturbance + respiratory depression —> need ventilator support + ICU admission necessary)
6. Propofol / other anaesthetic agents
7. Sodium valproate
記: O2 + Recovery position —> Rectal diazepam —> IV Phenytoin / Levetiracetam
Surgical considerations
Cause of sudden deterioration:
1. Head trauma
2. Surgical abdomen e.g. internal haemorrhage, intussusceptions, volvulus
—> may be related to Non-accidental injuries (e.g. abuse)
—> need to find out underlying cause
Psychological considerations
- Hospitalisation esp. ICU admission can be stressful to patient
- Stressful not just to patient but also immediate family members
- Support should extend to parents + family members
Encephalopathy (SpC Paed E-learning: Common Neurological Problems)
Definition:
1. Delirium (acute confusional state: perception, mental data processing and memory)
or
2. Altered level of consciousness, represents a rapid deterioration in cortical function
or
3. Behavioural change (e.g. confusion, excessive irritability) +/- Alteration in consciousness (e.g. lethargy / coma)
Causes:
Must make diagnosis early
1. Infection
- CNS infection
- Systemic infection / febrile illness leading to altered mental state
- Seizure / Epilepsy
- Convulsive / Non-convulsive state
- Epileptic encephalopathy - Metabolic
- IEM
- Uraemia
- Hyperammonia
- Hyper / Hypoglycaemia
- Lactic acidosis - Systemic
- Liver / Multisystem failure
- Hypertension - Hypoxic / Ischaemic
- Various causes - Others
- Cerebrovascular events
- Malignancy
- Toxic
No need to make urgent diagnosis, can wait
1. Parainfectious + Immune-mediated
- Acute disseminated encephalomyelitis
- Autoimmune encephalitis
Others:
1. Genetic
- Leukoencephalopathy
- Autosomal dominant acute necrotising encephalopathy
- Mitochondrial encephalopathy
Approach:
Step 1: Look for straightforward + treatable causes
- Blood (CBC, D/C, Gas, Glucose, Lactate, NH3, LRFT including Ca, PO4, Mg, TFT)
- Urine
- CSF
- EEG
- Imaging
Step 2: Basic IEM screening
- Blood
- Urine
Step 3: Think about immune-mediated encephalopathies, IEM, neurogenic causes
- Targeted investigations (Antibodies, Metabolites, DNA)
Emergency IEM screening tests (SpC Paed E-learning: Common Neurological Problems)
1st line:
1. Blood
- Gas
- Glucose
- Lactate
- NH3
- LRFT
- Electrolytes (Ca, PO4, Mg)
- CBC with film
- Urine
- pH
- Ketone
- Protein
- Glucose
- Reducing substances
2nd line:
3. Blood
- Ketone (Acetoacetate, 3-hydroxybutyrate)
- Amino acids
- Acylcarnitine
- Urine
- Organic acids including orotate, amino acids
3rd line:
5. Depends on results of 1st + 2nd line investigations + clinical correlation
