Respiratory Flashcards
percentage oxygen delivered by nasal cannula at 1,2 and 4 litres
1 litre- 24%
2 litre- 28%
4 litre - 36%
Rough equivalents nasal canulla to venturi masks
1 litre nasal canula= 24%, blue venturi= 24%
2 litre nasal canula= 28%, white venturi= 28%
4 litre nasal; canula= 36%, yellow venturi= 35%
Blue Venturi mask oxygen flow rate and % oxygen delivered
flow rate= 2-4L
% oxygen delivered= 24%
white Venturi mask oxygen flow rate and % oxygen delivered
flow rate= 4-6L
% oxygen delivered= 28%
Yellow Venturi mask oxygen flow rate and % oxygen delivered
flow rate= 8-12 L
% oxygen delivered= 35%
Red Venturi mask oxygen flow rate and % oxygen delivered
flow rate= 10-15 L
% oxygen delivered= 40%
Green Venturi mask oxygen flow rate and % oxygen delivered
flow rate= 12-15 L
% oxygen delivered= 60%
simple face mask oxygen flow rate and % oxygen delivered
flow rate= 5-10 L
% oxygen delivered= 30-40%
Non-rebreather mask (reservoir mask) oxygen flow rate and % oxygen delivered
flow rate= 15 L
% oxygen delivered= 70%
Medications contra-inidicated in asthmatics
- Beta-blockers (contra-indicated)
- NSAIDs (C/I if previous exacerbation related to NSAID or aspirin use)
- adenosine
6 Indications of hxt of severe asthma
Admission should be considered for patients with a history of severe asthma and any adverse psychosocial factor regardless of the severity of the current episode.
- Previous near-fatal asthma (ventilation, ICU)
- Previous admission for asthma in the last year
- Requiring maintenance therapy of 3 or more classes of asthma medication
- Heavy use of β2 agonist
- Repeated ED attendances with asthma
- ‘Brittle asthma’ (uncontrolled asthma despite maximum maintenance treatment or recurrent sudden severe episodes when asthma well controlled)
Moderate asthma features
Moderate acute asthma:
- PEFR 51-75% best or predicted
- No features of acute severe asthma
Mild asthma exacerbation:
- PEFR >75% best or predicted
- No features of acute severe asthma
Acute Severe asthma features (4)
The absence of any life-threatening feature and presence of any one of the following factors indicates that the current exacerbation is severe.
- PEFR <50% best or predicted
- Respiratory rate 25/min
- Heart rate 110/min
- Inability to complete sentences in one breath
Life threatening asthma features (9)
The presence of any one of the following signs or results indicates that the current exacerbation is life-threatening.
- Reduced conscious level
- Signs of exhaustion
- Hypotension
- Arrhythmia
- Cyanosis
- Poor air entry/ poor respiratory effort
- Silent chest
- PEFR <33% best or predicted
- SpO2 <92% or PaCO2 normal (4.6-6.0 kPa)
Near Fatal asthma features
Raised PaCO2 and/or needing high inflation pressures if ventilated.