Respiratory Flashcards
Define Apnoea
Cessation of respiratory airflow
Note: short breathing pauses of 5-10 seconds are normal and common in preterms
Define Apnoea of Prematurity
Cessation of breathing for >20 seconds, or <20 seconds with a drop in SpO2 and bradycardia
Give 3 causes of Apnoea of Prematurity
Immaturity of breathing responses to changes in O2 and CO2
Collapse of airways due to poor tone
Nasal Obstruction (neonates are obligate nasal breathers)
Define OSA and give some causes
Snoring associated with periods of ineffective breathing
Adenotonsillar Hypertrophy, Obesity, Macroglossia, Micrognathia
How might OSA present in a child?
Snoring and sleep disturbance
Daytime sleepiness
Enuresis
How would you investigate and manage OSA?
Ix - Sleep Study, CXR, EEG
Mx - CPAP, ?Weight Loss, ?Adenotonsillectomy
What is Expiratory Apnoea Syncope? (AKA Blue Breath Holding Spells)
Precipitated by anger/crying
Cannot catch breath (stuck in expiration)
Goes blue, stiff then limp with rapid recovery
Name three investigations for Apnoea
Lumbar Puncture
CXR
Bloods (U&Es, Glucose, Culture)
Define Wheeze
High pitched musical respiratory sound usually heard on expiration. Associated with airway narrowing and limitations.
Give 5 causes of acute wheeze
Viral Episodic Wheeze Bronchiolitis/Bronchitis Bacterial tracheitis Foreign Body Aspiration Anaphylaxis
Give two structural and two functional causes of chronic wheeze
Structural - Tracheobronchomalacia, Tracheal Web
Functional - Asthma, CF
How is a Wheeze managed?
Treat underlying cause
Beta Agonists and Steroids
Oxygen
Define Stridor
Harsh respiratory sound produced by turbulent flow in narrow upper airways, affected by severity of narrowing
What three associated symptoms with Stridor or should you ask about as a priority?
Fever
Drooling (Secure Airway, ENT referral)
Barking Cough (Dexamethasone, Intubate and Admit)
Give 5 causes of Acute Stridor
Croup (Laryngotracheobronchitis) Epiglottitis Bacterial Tracheitis Peritonsillar Abscess Anaphylaxis
Give two congenital causes and two acquired causes of Chronic Stridor
Congenital - Laryngomalacia, Subglottic Stenosis
Acquired - Vocal cord paralysis, Tumours
In an Acute Stridor or you should avoid looking at the throat until resus equipment is at hand. How else could you assess severity?
Only on crying? At rest? Chest Retraction? Cyanosis? Tachypnoea/Tachycardia?
Define Cyanosis
Bluish/Purplish discolouration of tissues due to increased concentration of deoxygenated haemoglobin in capillary beds
Mostly appreciated in lips/nail beds/mucous membranes
Can be central or peripheral
Give three AIRWAY causes of Cyanosis
Choanal Atresia
Laryngomalacia
Pierre Robin Syndrome
Give three BREATHING causes of Cyanosis
Hypoventilation/Apnoea
Pneumonia
Congenital Diaphragmatic Hernia
Give three CIRCULATION causes of Cyanosis
Anaemia
Methaemaglobinaemia
Cyanotic CHD
State five categories of a cough history
Onset (Any preceding symptoms) Duration Nature (Dry or Wet) Triggers Associated Sx
Give 3 viral causes of Acute Cough
URTI (Cold)
Laryngotracheobronchitis
Bronchiolitis
Give 2 bacterial causes of Acute Cough
Epiglottitis
Bacterial Pneumonia
How would an inhaled foreign body appear on a CXR?
The object may be visible on the CXR
Hyperinflation on affected side due to air trapping
Give three Pulmonary causes of a chronic cough
Asthma
Post Infectious
CF
Give three Extra - Pulmonary causes of a chronic cough
Post Nasal Drip
Cardiac
GORD
Define Protracted Bacterial Bronchitis
Chronic Wet Cough as a diagnosis of exclusion
Resolves with 2-6 weeks of treatment
State the boundaries for Tachypnoea in Neonates/Infants/Children/Adolescents
Neonates - >60
Infants - >50
Child - >40
Adolescent - >30
State 5 red flags of a Cough
Sudden Onset (choking) Weight Loss Night Sweats Cyanosis Clubbing
Define Breathlessness
Laboured or increased work of breathing from increased airway resistance, characterised by nasal flaring, grunting, and usage of accessory muscles
Give four differentials for breathlessness in a child
Airway obstruction
DKA
Pneumonia
CHD
What would point to a Cardiac cause of breathlessness in a child?
Squatting when fatigued
Poor weight gain
Hepatomegaly
Oedema
Asthma is the most common chronic condition in children. State the definition
Reversible and paroxysmal constriction of the airways
Early features include inflammatory exudate, and late features include airway remodelling
Asthma is a multifactorial disease in which susceptible individuals have an exaggerated response to various stimuli. Describe the classical pathophysiology.
Driven by TH2 cells which release cytokines resulting in activation of humoral system
Humoral system causes increased proliferation of mast cells/eosinophils/dendritic cells
Leukotrienes cause cytotoxicity and histamine causes exudate production
Give four risk factors for Asthma
Genetic (trend of atopy)
Prematurity
Parental Smoking
Early Viral Bronchiolitis
There are various triggers that affect Asthma, what effects do NSAIDs have?
Shunts the arachadonic pathway towards leukotriene production which is cytotoxic
How could you describe the pattern of wheezing in asthmatic individuals?
Infrequent - discrete episodes lasting a few days with no interval sx
Frequent - occurring 2 to 6 times weekly
Persistent - occurring most days and may occur at night
What is Pre- School Wheeze?
50% have at least one significant wheeze by their 5th Birthday
Asthma is normally a clinical diagnosis, what are the two main investigations that could be carried out?
Spirometry - if child is over 6, should be normal in between exacerbations if well controlled
PEFR - if over 5y/o
What are Bronchial Provocation Tests?
A test used in uncertain cases to assess airway hyper responsiveness to histamine or metacholine
How is the Exhaled Nitric Oxide investigation used?
Produced in bronchial epithelial cells, and it’s production is increased with TH2 driven inflammation
Positive result is >35ppb
Note: Also raised in hay fever
What investigations could be done to rule out differentials of Asthma?
Oesophageal pH Bronchoscopy Chlorine Sweat Test Nasal Brush Biopsy (exclude PCD) HRCT