Resp Flashcards
what are the signs of respiratory distress?
grunting, intercostal + subcostal recession ie use of accessory muscles bc lung compliance is poor or airway resistance is high, tracheal tug, abdominal breathing, nasal flaring (increases upper airway diameter and reduces resistance and work of breathing), tachypnoea > 60/min, use of accessory muscles, head bopping.
what is stridor?
harsh inspiratory musical sound resulting from partial upper airway obstruction in the larynx and upper trachea.
what is wheeze? What are the common causes?
due to partial obstruction/abnormal narrowing of the intrathoracic airways (large + small) resulting in a musical note during EXPIRATION.
Common causes- mucosal (ie resp mucosal lining) inflammation + swelling (Bronchiolitis); bronchospasm (Asthma); mucus/ FB obstruction, anaphylaxis (recurrent), CF.
What are the causes of bronchiolitis?
RSV (80%)
Adenovirus
Rhinovirus
Parainfluenza virus
What are the clinical features of bronchiolitis?
Appearance: Signs of Respiratory Distress e.g. Subcostal + intercostal recession due to obstruction causing increased airway resistance, sternum prominent due to hyperinflation of lungs.
Bedside: O2 sats monitor, O2 cannula
Auscultation: Prolonged expiration (due to hyperinflation)/ high pitched Wheeze (partic expiration) due to obstruction of small airways.
Fine end-inspiratory crackles - creps
Palpation: Displaced liver (due to hyper inflation of lungs)
What is the natural history of bronchiolitis?
Affects infants up to age ~1 years old.
coryzal (common cold- nasal discharge+ blockage) symptoms precede dry cough and increased SOB.
Feeding is often affected due to increased SOB.
Who might be at risk of more severe Bronchiolitis? How is this prevented?
pre-term infants partic if have bronchopulmonary dysplasia/ underlying lung disease e.g. CF,
or CHD, or Immunodeficiency.
Monthly injections of Pavalizumab IM providing exogenous immunity to RSV during first 2 winters of life.
What is the physiology behind infants grunting?
self-induced auto-PEEP (positive end expiratory pressure), which allows infants to keep their smaller airways and alveoli open (-ve pressure causes collapse).
The noise results from the sudden closure of the glottis during expiration in an attempt to maintain Functional Residual Capacity which prevents alveolar atelectasis (collapse) maintaining area for gas exchange.
what is the pathophysiology of bronchiolitis?
The virus infects the respiratory epithelial cells of the small airways, leading to necrosis, inflammation, oedema, and mucus secretion. The combination of cellular destruction and inflammation leads to obstruction of the small airways.
The physiological and clinical results consist of hyperinflation (due to obstruction), atelectasis (obstruction prevents air replenishment in these spaces and residual air is absorbed by vessels quicker than it is replaced leading to collapse), and wheezing (secondary to obstruction). In severe cases, interstitial inflammation and alveolar infiltrates also develop.
How is acute bronchiolitis managed?
Supportive measures
Admitted if: Apnoea, persistent O2 sats below 90%, inadequate fluid intake 50-75% normal, severe respiratory distress eg. RR > 70, grunting, marked chest recession.
1. Humidified Oxygen via cannula/ head box concentration guided by sats to maintain ~ 90%
2. Hydration try to maintain feeding, if drops, can use NGT or IV hydration.
Good Hand hygiene, usually about half will go on to have a recurrence of cough + wheeze.
what is the natural history of asthma?
interaction of genetics, environment such as allergens, smoking, emotional upset, URTI, cold air and atopy.
Triad of:
bronchial inflammation- oedema, excess mucus, immune cell infiltration
bronchial hyperresponsiveness- exaggerated bronchoconstriction in response to inhaled allergens
airway narrowing- reversible airway obstruction
Over time, airway remodelling occurs secondary to chronic inflammation ***
what are interval symptoms?
- night time cough
- SOB on exertion
- wheeze
in the absence of a viral illness.
How would you manage a severe acute exacerbation of asthma?
- 15L of O2 via non re-breathe mask
- Nebs of Salbutamol (2.5 mg under 8/ 5mg over 8)+ Ipratropium (125mg under 5/ 250mg over 5) (Can give up to 4 times of the two if req)
- Oral corticosteroids (Inhaled are NOT indicated in this instance)
- IV Mg2+/ Salbutamol/ Aminophylline/ Steroids
- Transfer to HDU
During the first 3 years of life how is wheeze categorised?
viral wheeze- wheeze only in the context of viral illness
multi trigger wheeze- wheeze caused by multiple things e.g. allergens + viral, more likely to develop into asthma and benefit greatly from asthma therapies.
asthma- rarely diagnosed at this age bc inappropriate.
What is multi trigger wheeze?
wheeze triggered by viruses, cold air, dust mites, exercise, animal hair. When viral wheeze is associated with interval symptoms - ie night time cough, SOB on exertion and wheeze in absence of virus, and evidence of allergies to inhaled allergens eg. pollen, it is called ‘atopic asthma’.
Remember atopy is strongly assoicated with eczema, hayfever (rhinoconjunctivitis) and food allergy.
What is the stepwise management of asthma?
Step 1. Short-Acting Inhaled B2 Agonist e.g. Salbutamol 100-200mcg (1-2puffs) before exercise/ every 4-6 hours + Very Low dose Inhaled Corticosteroid e.g. Beclometasone Dipropionate 50mcg 2 puffs BD OR if <5 years old, Leukotriene R Antagonist e.g. Montelukast
Step 2. Short-Acting Inhaled B2 Agonist PRN (same dosage/freq as above) + Very low dose Inhaled Corticosteroids + (if <5years) Leukotriene R Antagonist e.g. Montelukast 4mg OD OR (if >5years) Long-Acting Inhaled B2 Agonist e.g. Salmetarol
Step 3. Options- if no response to LABA, Stop LABA + increase ICS to low dose (100mcg 2 puffs BD); OR if some response, maintain LABA+ increase ICS to low dose; OR maintain LABA + ICS dosage + Add LTRA
Step 4. Increase ICS to Medium dose Inhaled Corticosteroid e.g. Beclometasone Dipropionate 200mcg two puffs BD OR consider adding SR Theophylline + Refer to specialist services
Step 5. Daily oral steroid tablets + Medium dose ICS + Consider other tx options to minimise oral steroid
What are the indicators of acute severe asthma?
Can’t complete sentences in one breath or too breathless to talk or feed
SpO2 <92%
PEF 33–50% best or predicted
Heart rate >140/min in children aged 1–5 years
>125/min in children >5 years
Respiratory rate >40/min in children aged 1–5 years >30/min in children >5 years
What is the stepwise management of asthma?
Step 1.
Short-Acting Inhaled B2 Agonist e.g. Salbutamol 100-200mcg (1-2puffs) before exercise/ every 4-6 hours
Step 2.
Add Very Low dose Inhaled Corticosteroid e.g. Beclometasone Dipropionate 50mcg 2 puffs BD OR if <5 years old, consider Leukotriene R Antagonist e.g. Montelukast
Step 3.
Add (if <5years) Leukotriene R Antagonist e.g. Montelukast 4mg OD or consider increasing ICS to 100mcg 2 puffs BD
Add (if >5years) Long-Acting Inhaled B2 Agonist e.g. Salmetarol and assess response:
§ if no response to LABA, Stop LABA + increase ICS to low dose (100mcg 2 puffs BD) or (200mcg 2 puffs BD in teens) + consider LTRA and/or SR Theophylline
§ if some response, maintain LABA+ increase ICS to low dose
§ good response- maintain LABA
Step 4.
In <5 years old: Refer
In 5-12 years old: Increase ICS to Medium dose Inhaled Corticosteroid e.g. Beclometasone Dipropionate 200mcg two puffs BD (or 400mcg two puffs BD in teens) + consider adding SR Theophylline/ LTRA
Refer to specialist services
Step 5.
In 5-12 years old: Maintain ICS at Medium dose Inhaled Corticosteroid e.g. Beclometasone Dipropionate 200mcg + Daily oral steroid tablets (lowest possible dose) + Refer
In teens: Maintain ICS at 400mcg dose Inhaled Corticosteroid + Daily oral steroid tablets (lowest possible dose) + refer
What features of the history suggest asthma?
symptoms worse at night and early in the morning
symptoms with no viral trigger
interval symptoms between acute exacerbations
personal/ family hx of atopy
response to asthma therapy
what is your ddx for asthma?
GOR, CF, VIW, Bronchiolitis, Croup
what clinical signs suggest asthma?
normal examination between exacerbations.
long standing may find hyperinflated chest + exp wheeze + prolonged expiratory phase.
wet cough + finger clubbing/ poor growth might think of bronchiectasis/ CF. loose cough w/o wheeze persistent bacterial bronchitis.
Peak Flow- diurnal variation, worse in morning than in evening and day to day variation if not controlled.
to assess the severity of asthma, what questions are imp to include?
frequency of symptoms, triggers, impact on sport/ gen activities, sleep disturbed?, severity of interval symptoms?, missed school, how exacerbations are managed
what are the clinical features of pneumonia?
fever, cough and tachypnoea (>60). sometimes preceded by URTI.
Lethargy + poor feeding.
Signs=
tachypnoea (>60) **
What is croup? What are the features?
Coryza + fever followed by:
Hoarseness (inflammation vocal cords)
Inspiratory Stridor
Barking Cough (tracheal oedema + collapse)
Chest recession + increased work of breathing
Symptoms often worse at night.
Caused by: Viruses - parainfluenza, rhinovirus, RSV
Ages: 6m- 6y but peak at 2y.
Admission if <12m (narrower airway), less parental confidence, severity of obstruction (stridor- at rest/ biphasic more severe + chest recession)
