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
