Asthma Flashcards
Asthma - Definition
A clinical syndrome characterized by increased irritability of the tracheobronchial tree leading to recurrent episodes of reversible airway obstruction following exposure to a stimulus
Goal of Care
Improve airflow through the medium and small airways and transport to hospital
Overview
Asthma attacks can be of rapid onset due to increased bronchoconstriction. As the episode progresses, the linings of the airways become congested w/ swollen cells and mucous produced from those cells
Mild to moderate asthma exacerbations are the most common, and are simple to treat. However, careful monitoring of the pt’s condition must be exercised in every case since symptoms can progress unexpectedly and rapidly
Death from asthma is rare, but is increasing b/c pts have become complacent w/ how well beta agonists work and so do not seek care early in attack
Features of Severe and possibly Fatal Attacks
History
- Rapid and severe onset
- Exposure to a known precipitant - allergens or other environmental
- Hx of non-compliance w/ treatment
- Previous life-threatening asthma attacks.
- Attendance to an emergency department w/ asthma in last year
- Multiple types of asthma drugs prescribed in the last year (indicates their asthma is not stable)
- Increasing frequency of beta-agonist use - the pt who has used his or her puffer many times in the past day or two
Physical
- Upright or forward sitting (tripod) position
- Difficulty speaking full sentences
- Decreased O2 sats <90% - asthmatics breathe quickly and the problem is ventilation, not oxygenation. Any decrease in O2 saturation is an ominous sign
- No wheeze - this may be a sign of no air entry at all (silent chest)
Guiding Principles
Pts w/ failing resps require support . Often a little supportive ventilation can dramatically improve the pt’s condition as it provides appropriate ventilation, oxygenation and decreases the work of breathing
CPAP
Guiding Principles - EPI
EPI may be indicated in a younger otherwise healthy pt w/ failing resps and DLOC who is not improving w/ salbutamol
Its beta adrenergic properties reduce bronchospasm and its alpha adrenergic propertiies may reduce swelling in the mucosa
Most commonly administed IM
Must consult w/ CliniCALL before administering EPI
Guiding Principles - Magnesium
Magnesium sulfate may be a useful 3rd line medication for severe asthma unresponsive to b-agonist and ipatropium
It is not effective for other causes of resp distress. Since its action is lower in onset, magnesium should be considered in severe cases where there are longer transports - given enroute - as an infusion
Special Note
Intubation should only be required in the most exceptional cases. Intubating an asthmatic is a last resort since the introduction of the tube can dramatically increase bronchospasm in an already compromised patient.
Asthma patients with a history of COPD do not do well when intubated and ventilated. Intubation can exacerbate the primary problem which is distal air trapping. It is often difficult to wean these patients off a ventilator
Other considerations
Droplets from nebulization can carry virus particles.
For a patient with fever (subjective) and mild to moderate wheeze consider transport w/o administering nebs
Always wear PPE when treating a coughing patient.
D/c the neb prior to entering the facility and until triaged to an appropriate bed.
Intervention Guidelines - EMR/PCP
EMR
Position the pt upright
Supp O2
PPV for failing resps
PCP
All above, plus
Bronchodilation as required
- Salbutamol - 5mg via neb - repeat as req’d - no max dose
Failing Respirations/Severe Life Threatening
- EPI - 0.5mg IM - max dose 0.5mg
Mandatory call to CliniCALL
Non-Invasive ventilation as req’d
- CPAP
Mandatory call to CliniCALL
Intervention Guidelines - ACP
Anticholinergic therapy
- Ipatropium - 0.5mg via neb w/ salbutamol
as required (obvs signs of hypoperfusion) - EPI 50-100mcg 1:10,000 IV increments to effect - max dose 0.3mg
Relaxation of airway smooth muscle
- Magnesium Sulfate - 2g/250cc NS infused over 20mins
Intubation as per Adult Induction Guidelines
Further Care
Asthma
- IV beta agonists, magnesium sulfate steroids
- Anaesthetic agents
- CPAP/BiPAP
- Methylxanthines
COPD Exacerbations
- Antibiotics
- Steroids
- Methylxanthines
- CPAP/BiPAP
