The case of the breathless teenager Flashcards
Tachypnoea
tachypnoea
Increased respiratory rate, usually > 20 per minute
dyspnoea
unpleasant awareness of increased respiratory effort
hyperpnoea
increased level of ventilation/increased VE
Minute Ventilation (VE)
volume of air inspired or expired per minute (l/min)
Hyperventilation
increased pulmonary ventilation in excess of metabolic demand causing decreased pCO2
orthopnoea
Shortness of breath when lying flat
paroxysmal nocturnal dyspnea
sudden awakening from sleeping with shortness of breath
bradypnoea
abnormally slow breathing
Cheyne-Stokes respiration
abnormal cycle of breathing characterized by a gradual increase of depth and sometimes rate to a maximum level, followed by a decrease, resulting in apnea
what controls normal breathing?
medulla oblongata
What nerve conveys sensation of breathing/dyspnoea?
vagus nerve
respiratory system receptors
carotid body receptors
pulmonary artery baroreceptors
central medullary chemoreceptors
lung stretch receptors
pulmonary causes of dyspnea
COPD fibrosis airway obstruction PE asthma pneumonia neoplasm anaphylaxis
cardiovascular causes of dyspnoea
pulmonary oedema ACS arrhythmia tamponade valvular disease
2 infections that could cause dyspnoea
2 infections that could cause dyspnoea
epiglottitis
pneumonia
3 traumatic causes of dyspnoea
flail chest
pneumothorax
haemothorax
psychiatric causes of dyspnoea
anxiety
hyperventilation
metabolic causes of dyspnoea
metabolic acidosis
toxins
renal failure
ascites
obesity
pregnancy
ascites
obesity
pregnancy
prevalence of asthma
most common respiratory disease worldwide
asthma symptoms
shortness of breath, wheezing, cough, chest tightness
is there a gold standard test for asthma?
no
what investigations could be done in suspected asthma?
PEFR variability spirometry FeNO inducible airway hyperresponsiveness eosinophil count atopy tests
what FeNO is expected in someone with airway inflammation?
above 40ppb
do negative investigations fully rule out asthma?
no as can be normal when well controlled
When is asthma most likely?
when clinical features match asthma and a positive objective test
asthma mimics
airway obstruction inducible laryngeal obstruction cough hypersensitivity sinus disease exercise induced laryngeal obstruction
Asthma triggers
cold air smoke URTI exercise stress inhaled allergens poor treatment adherence
criteria for moderate acute asthma
increasing symptoms
PEF>50-75% best
criteria for severe acute asthma
RR>25 can't complete sentences HR >110 PEF 33-50% best (any 1)
criteria for life threatening asthma
altered consciousness exhaustion cyanosis hypotension PEF<33% best
when does asthma become near fatal?
when so severe mechanical ventilation is required or PaCO2 becomes raised
treating acute asthma (6)
nebulised salbutamol oxygen if hypoxemic oral prednisolone nebulised ipratropium bromide consider IV magnesium sulphate consider aminophylline
Aminophylline
Bronchodilator
poor data on whether actually useful in acute asthma but try with severely ill patients not responding to other therapies
1st offered treatment for a newly diagnosed asthmatic
SABA e.g. salbutamol
next step if SABA not controlling asthma
SABA + low dose ICS
next step if SABA + low dose ICS not controlling asthma
SABA + low dose ICS + LTRA /LABA - contradicted
treatment options if very unresponsive asthma
adding a LAMA or theophylline but will need specialist input
