The Child with breathing difficulties Flashcards
Define respiratory failure.
The inability of physiological compensatory mechanisms
To ensure adequate oxygenation and carbon dioxide clearance
….
resulting in arterial hypoxia
- with or without hypercapnia.
Why do young children and infants develop respiratory failure more easily than adults?
Due to differences in:
- Immunity
- Structure
- Function
Immunity:
- immature immune system
- have not acquired immunity to viruses and bacteria yet
Structure:
- Thoracic cage more compliant
- => less support for the maintenance of lung volume
- i.e. when there is increased resp effort due to airway obstruction this causes chest wall recession and makes breathing less efficent
- small upper and lower airways
- easily obstructed (secretions, mucosal swelling, foreign body)
- increased airway resistance (begins to decrease from 2 months of age)
- fewer alveoli => ventilation-perfusion mismatch more likely
- pulmonary vascular bed muscular in infancy => vasoconstriction => R to L shunting => in neonates, ductal opening => ventilation - perfusion mismatch => hypoxia worse
Function:
- lung volume at the end of expiration = similar to closing volume in infants => small airways may close => hypoxia
- increased tendency to bronchoconstriction due to alveolar or airway hypoxia
- respiratory muscles inefficient
- fewer type I, highly oxidative, fatigue resistant fibres
- diaphragm = main resp. muscle
- IC & accessory muscles = little contribution
- resp muscle fatigue can happen rapidly => resp failure / apnoea
- paradoxical inhibition of resp drive in 1-2 months old => may present with apnoea/ hypoventilation instead of resp distress
- fetal Hb (HbF) present in sig. quantities until aged 4-6 months => oxygen dissociation curve shifted L => oxygen is given up less readily to tissues => prone to tissue hypoxia & acidosis
Describe the 8 mechanisms causing breathing difficulty in children, with examples (top to bottom).
- Upper airway obstruction
- croup
- epiglottitis
- foreign body
- Lower airway obstruction
- asthma
- VIW
- bronchioltis
- tracheitis
- Lung disorders
- pneumonia
- pulmonary oedema (e.g. cardiac disease)
- Around the lungs (disorders)
- PTX
- pleural effusion/ empyema
- rib fractures
- Respiratory muscle disorders
- neuromuscular disorders
- Below the diaphragm disorders
- peritonitis
- abdominal distension
- Increased respiratory drive
- DKA
- shock
- anxiety attack
- poisoning
- Decreased respiratory drive
- coma
- convulsions
- raised ICP
- poisoning
How does airway resistance relate to the radius of the airway?
Airway resistance
INVERSELY PROPORTIONAL to
the 4th power of the RADIUS
i.e. radius / 2 = 16 x the airway resistance
What is stridor and what is it caused by?
High pitched inspiratory noise.
Caused by obstruction of the larynx or trachea.
What is stertor and what is it caused by?
Give examples.
Stertor/ snoring = low pitched inspiratory noise - caused by partial pharyngeal obstruction.
- poor airway positioning
- depressed conscious level
What is an important historical features when asking about noisy breathing?
- Aggravating/ relieving factors e.g. FPECS
- feeding
- position
- exercise
- crying
- sleep
- Is the voice/ vocalisations normal? e.g. hoarse voice in croup
What do bubbly/ gurgly noises suggest?
Give examples.
Pharyngeal secretions
- children with neurodisability (difficulty in spontaneously clearing secretions)
- fatigued (unable to clear secretions with own cough)
- depressed conscious level (“)
What is wheeze?
Expiratory noise caused by lower airway obstruction (mainly).
What does an expiratory grunt suggest?
- sign of resp distress
- suggests small aiway closure OR alveolar filling e.g. pneumonia, pulmonary oedema
- trying to create PEEP (positive end expiratory pressure) to keep the alveoli open at the end of expiration
What kind of pain can pneumonia cause?
Chest or abdominal pain.
What kind of pathology does chest pain usually suggest in children?
Usually respiratory e.g. pneumonia.
Cardiac causes less likely.
How do breathing difficulties often present in infants?
With feeding problems - as this is one of the most strenuous activities they do.
What are the signs that suggest cardiac failure as the cause of breathing difficulties (from top to bottom)?
What can cause this?
From top to bottom:
- Cyanosis - not corrected by O2 therapy, or Pallor
- Sweating, restlessness, fatigue/ effort intolerance in older children
- Feeding difficulty, growth failure, anorexia
- JVP - raised
- Chest pain
- Tachycardia - out of proportion to WOB - & Tachypnoea
- Cough
- Inspiratory crackles
- Heart enlarged, displaced apex beat (CXR large heart and pulmonary congestion)
- Gallop rhythm/ murmur
- Liver enlarged
- Abdominal pain
- Femoral pulses absent
- Cool peripheries (Cardiogenic shock)
Congenital or acquired heart disease.
Describe the primary assessment and resuscitation of children with breathing difficulties.
A:
- Patent?
- Look, listen and feel for breath
- vocalisations?
- No air movement?
- chin lift/ jaw thrust +/- rescue breaths
- –> reassess
- airway adjunct e.g. pharyngeal airway device (LMA)
- intubation
B: WOB/ effort of breathing
- COUNT = Obs
- RR
- Sats - OFF & ON O2 (N = 97 - 100%) - check the waveform!
- Emergency Mx:
- Consider SUCTION
- Give High flow O2 15 L/ min (mask with reservoir bag)
- can use NC if flow <2L/ min achieves sats 94-98%
- Bag-valve-mask ventilation or ETT + intermittent positive pressure ventilation if inadequate effort
- LOOK - resp distress
- recessions (SC, IC, sternal, TT) - NB may decrease as child goes into resp failure
- grunting / nostril flaring/ accessory muscles (sternomastoid - head bobbing)
- drooling?
- degree of chest expansion/ abdominal excursion (infants)
- pallor/ cyanosis (SaO2 < 70% - pre-terminal)
- urticarial rash?? –> ANAPHYLAXIS
- LISTEN
- gasping (pre-terminal - sign of severe hypoxia)
- stridor (laryngeal/tracheal obstruction - mainly insp. but also exp. if severe)
- wheeze (expiratory) & prolonged exp. phase (lower airway narrowing)
- asymmetrical or bronchial breathing sounds
- silent chest?
NB:
tachypnoea + increase TV
+ NO recessions
= metabolic acidosis (circulatory failure)
C:
- COUNT
- HR
- BP - use the correct size cuff! (NB hypotension is a pre-terminal sign - cardiac arrest is imminent! Hypertesion - consider coma and raised ICP)
- Urine output (inadequate renal perfusion - ask about wet nappies!)
- children < 1 ml/ kg/ hr
- infants < 2 ml/ kg/ hr
- LOOK
- mottled, cold, pale, cyanosed skin
- CRT (Normal = 2 secs) - less sensitive if cold env.
- raised JVP
- FEEL
- Skin - clammy? warm? cold?
- peripheral oedema?
- pulse volume
- peripheral vs central (absent peripheral and weak central = advanced shock)
- bounding = sepsis, hypercapnia, arteriovenous shunt e.g. PDA
- absent femoral pulses (cardiac failure)
- LISTEN
- gallop rhythm
- murmur
- Emergency Mx:
- VENOUS/ intraosseous ACCESS FOR BLOODS INCL. CRP, culture, G+S, gas (BM)
- crystalloid 20 ml/ kg (10 ml/kg for cardiac pts)
- if signs of circulatory failure
- OR when Positive pressure ventilation is started
D: mental status
- hypoxic/ hypercapnic –> agitated/ drowsy / LOC + muscular hypotonia (hypoxic cerebral depression)
- circulatory failure can lead to agitation/ drowsiness –> LOC (due to poor cerebral perfusion)
E:
- enlarged liver (a sign of heart failure)
- temperature (fever)
What is tidal volume (TV)?
The normal volume of air displaced between inhalation and exhalation
when extra effort is NOT applied.
(usually 5-7 ml/kg)
What are 3 important differentials relating to INGESTION
which must not be forgotten in the child presenting with breathing difficulties?
(FAP)
- FOREIGN BODY ASPIRATION (history of choking)
- ANAPHYLAXIS (exposure to allergen) - look for urticarial rash/ angioedema etc!!!
- POISONING
Describe the causes and presentations of stridor (use VITAMIN C+D).
- Vascular
- angioneurotic oedema
- itching
- facial swelling
- urticarial rash
- anaphylaxis
- angioneurotic oedema
- Infectious (6x) ABCDE + I
- Abscess (retropharyngeal/ peritonsillar)
- drooling
- septic
- Bacterial tracheitis
- harsh cough
- septic
- chest pain
- Croup (viral laryngo-tracheo-bronchitis)
- barking cough
- hoarse voice
- fever
- coryzal
- Diphtheria
- unnimmunised
- travel to endemic area
- Epiglottitis
- drooling
- muffled voice (& quiet stridor)
- septic
- no cough (NB no C in the name)
- Infectious mononucleosis
- sore throat
- large tonsils
- Abscess (retropharyngeal/ peritonsillar)
- Inflammatory
- Inhalation of hot gases (house fires)
- facial burns
- soot around mouth
- Inhalation of hot gases (house fires)
- Trauma
- bruising
- neck swelling
- crepitus
- Other
- Foreign body aspiration
- sudden onset
- history of choking
- Depressed conscious level/ fatigue causing partial obstruction from secretions
- Foreign body aspiration
What is angioneurotic oedema?
- rare disease
- relapsing subcutaneous or submucosal oedema
- deficiency in C1Inh (inhibitor of the C1 fraction of complement)
- may cause fatal laryngeal oedema
Describe the emergency Mx of partially obstructed airway from secretions due to a depressed consciousness level.
- call senior support EARLY
- SUCTION (if NO stridor)
- chin lift/ jaw thrust (if stertor)
- continuous positive airway pressure using Ayre’s T piece (face mask, oxygen flow and breathing circuit) - if reduced consciousness, whilst help awaited
- oro or nasopharyngeal airway
- intubation may be needed
Describe the emergency Mx of croup.
- Call for help early
- anaesthetics (in case intubation necessary)
- ENT (in case emergency tracheotomy necessary)
- Humidified O2 via FM
- Adrenaline nebs (with O2 via FM)
- 0.4 mg/ kg or 0.4 ml/ kg of 1:1000 (max 5ml)
- starts to take effect in 10-30 mins, lasts 2 hours
- buys time for steroids to kick in
- can be repeated
- may cause tachycardia
- if no response ? bacterial tracheitis, epiglottitis, foreign body
- Steroids
- oral dexamethasone (0.15 mg/ kg)
- oral prednisolone (0.5 - 1 mg/kg)
- budesonide nebs (2mg)
- all can be repeated after 12 hours if needed
- neb if vomiting/ refusing to take oral
- start to work after 30 mins
- reduced the need for hospitalisation/ intubation
- Continuous cardiac monitoring
- Sats
- check sats on air intermittently
- hypoxia is a late sign
- due to: airway obstruction –> ventilation perfusion mismatch –> alveolar hypoventilation
- Intubate if deterioration (may need smaller tube than normally required)
- increasing HR/ RR
- chest retraction
- cyanosis
- exhaustion
- confusion
Describe the emergency Mx of foreign body aspiration.
- Contact ENT/ anaesthetics urgently
- Do not upset the child - this may jeopardise the airway (NB coughing may move the object into the trachea and cause life threatening obstruction)
- Laryngo-bronchoscopy under general anaesthetic ideally - or if stridor then gaseous induction of anaesthesia
- Direct laryngoscopy with Magills forceps to remove a visible foreign body - only in extreme cases of life threat!
When should you suspect foreign body aspiration?
History of inahalation or witnessed choking episodes.
Describe the emergency Mx of epiglottitis.
- Contact a senior anaesthetist & ENT urgently
- do not lie the child down, or upset the child (risks jeopardising the airway)
- can consider nebulised adrenaline or steroids ONLY if they do not upset the child (uncertain benefit)
- gaseous induction of anaesthesia
- lie child on their back
- laryngoscopy and intubation
- this may be difficult due to severe swelling and inflammation of the epiglottis (cherry red epiglottis)
- use a smaller tube than the one normally required
- most can be extubated at 24-36 hrs and recover fully in 3-5 days
- Emergency tracheotomy by ENT in the event of failure
- Blood culture + IVAB (Cefotaxime/ ceftriaxone)
What are the 6 main Sx of croup?
- Stridor
- initially when tracheal narrowing is minor, inspiratory & only when child is upset/ hyperventilating
- later also at rest & during expiration
- +/- wheeze if infection affects the bronchi
- Barking cough
- Hoarse voice
- Variable degree of resp distress
- high HR/ RR
- SC/ IC/ sternal recessions
- hypoxia
- agitation
- Fever (1-3 days)
- Coryza (“)
NB Sx often worse at night.
What is the commonest pathogen responsible for croup?
Name 3 other viruses which can cause croup.
Parainfluenza
Others:
- RSV
- Influenza
- Adenovirus
What is the peak incidence of croup and what ages are normally affected?
2 years old
(6 months to 5 yo)
What is the other name for croup?
Viral laryngo-tracheo-bronchitis.
What is the other name for bacterial tracheitis?
Pseudomembranous croup.
What organisms causes bacterial tracheitis (pseudomembranous croup)?
What does this cause?
- Staphylococcus aureus
- Streptococci
- Hib
- copious, purulent secretions
- mucosal necrosis
How can you distinguish bacterial tracheitis & epiglottitis?
Children with either may look septic.
Bacterial tracheitis:
- croupy cough
- no drooling
- chest pain
- LONGER Hx
Epiglottitis:
- no cough
- drooling
- muffled voice
Describe the emergency Mx of bacterial tracheitis.
- IVAB
- ceftriaxone/ cefotazime
- flucloxacillin
- Intubation + Ventilation
- 80% of children
Which is more common - croup or epiglottitis?
Which children are at risk?
Croup is much more common than epiglottitis.
Children at risk:
- unimmunised/ from countries where Hib immunisation is not routine
- vaccine failure
What is the mechanism of epiglottitis?
What is the main responsible organism for epiglottitis?
Haemophilus influenza B (Hib).
What is the most common age group for epiglottitis?
2-6 years old
(but can also occur in infants and adults)
Describe the signs and symptoms of epiglottitis.
- high fever > 39
- lethargy
- soft inspiratory stridor
- increasing resp distress over 3-6 hours (acute onset)
- minimal/ absent cough
- child sits immobile
- chin slightly raised, mouth open, drooling saliva (too painful to speak/ swallow saliva)
- septic appearance - pale, poor peripheral circulation
What is the recovery like for epiglottitis?
- most children can be extubated in 24-36 hours
- recover fully in 3-5 days
- complications rare e.g.
- hypoxic cerebral damage
- pulmonary oedema
Can foreign bodies be seen on CXR?
- not the majority - most objects are radio-lucent
- 20% of cases with aspirated foreign body - CXR is normal
- may be secondary evidence of
- gas trapping
- atelectasis
- mediastinal shift
- flat objects e.g. coins align in
- trachea - in the sagittal plane
- oedophagus - anterior plane
Describe the emergency management of heart failure.
- B
- high flow O2 via face mask with reservoir
- C
- Cardiogenic shock? –> TREAT
- Diuretics
- e.g. frusemide (loop diuretic) + amiloride/ spironolactone (potassium sparing) BD or TDS
- orally or first dose IV in severe cases
- check electrolytes before starting
- Use for:
- myocarditis
- pulmonary congestion due to large L to R shunt e.g. via PDA, ASD, VSD or aortopulmonar window/ truncus arteriosus
- in these cases:
- signs of heart failure but NO shock
- oxygen sats normal or respond to O2 therapy
- in these cases:
