Resp Flashcards
(79 cards)
Features of moderate acute asthma
Increasing symptoms
SpO2 ≥92%
PEF >50–75% best or predicted
No features of acute severe asthma
Features of acute severe asthma
- PEF 33–50% best or predicted
- respiratory rate ≥25/min
- heart rate ≥110/min
- inability to complete sentences in one breath
• SpO2 ≥92%
• Pulse ≥110 beats/min
Features of life-threatening
asthma
PEF <33% best or predicted SpO2 <92% PaO2 <8 kPa Altered conscious level Exhaustion Arrhythmia Hypotension Cyanosis Silent chest Poor respiratory effort ’normal’ PaCO2 (4.6–6.0 kPa)
Clinical features of patients with
severe asthma
severe breathlessness (including too breathless to complete sentences in one breath), tachypnoea, tachycardia, silent chest, cyanosis, accessory muscle use, altered consciousness or collapse
What initial special test can you do to assess the severity of asthma
PEF or FEV1 are useful and valid measures of airway
calibre. PEF is more convenient in the acute situation
What do the BTS guidelines state with regards to oxygen therapy in acute asthma attacks?
Give controlled supplementary oxygen to all hypoxaemic patients with acute severe asthma titrated to maintain an SpO2 level of 94–98%. Do not delay oxygen administration in the absence of pulse oximetry but
commence monitoring of SpO2 as soon as it becomes available
What is the initial pharmacological therapy for a moderate asthma attack in the ED?
• Salbutamol 5mg nebulized with oxygen and give prednisolone 30mg PO.
• If PEF remains <75%, repeat salbutamol.
• Monitor oxygen saturation, heart rate, and respiratory rate.
(give one puff at a time; according to response, give another puff every 60 seconds up to maximum of 10 puffs)
Pharmacological management in acute severe asthma
Give β2 bronchodilator (salbutamol 5 mg) by oxygen-driven nebuliser
Immediate management of life threatening asthma
Obtain senior/ICU help now if any life-threatening features are present
IMMEDIATE MANAGEMENT
• Oxygen to maintain SpO2 94–98%
• β2 bronchodilator with ipratropium
- via nebuliser (preferably oxygen-driven), salbutamol
5 mg and ipratropium 0.5 mg
• Prednisolone 40–50 mg orally or IV hydrocortisone
100 mg
Measure arterial blood gases
Markers of severity:
• ‘Normal’ or raised PaCO2 (PaCO2>4.6 kPa; 35 mmHg)
• Severe hypoxia (PaO2 <8 kPa; 60 mmHg)
• Low pH (or high H+)
• Give/repeat salbutamol 5 mg with ipratropium 0.5 mg by oxygen-driven nebuliser after 15 minutes
• Consider continuous salbutamol nebuliser 5–10 mg/hr
• Consider IV magnesium sulphate 1.2–2 g over 20 minutes
• Correct fluid/electrolytes, especially K+ disturbances
• Chest X-ray
• Repeat ABG
THEN
ADMIT
Patient accompanied by a nurse or doctor at all times
What should you be doing at all times during an episode of acute asthma attack in the ED?
OBSERVE AND MONITOR
• SpO2
• heart rate
• respiratory rate
What is the next step after back to back nebs and pt is still not improving in moderate and acute severe asthma?
Repeat salbutamol 5 mg nebuliser
Give prednisolone 40–50 mg orally
DDx acute asthma
- Acute infective exacerbation of COPD
- Pulmonary oedema
- Upper respiratory tract obstruction
- Pulmonary embolus
- Anaphylaxis
Hx acute asthma in ED
- Ask about usual and recent treatment
- Previous acute episodes and their severity
- Best peak expiratory flow rate (PEF)
- Have they been admitted to ICU?
Ix acute asthma
- PEF—but may be too ill
- Arterial blood gases if saturations <92%;
- CXR (if suspicion of pneumothorax, infection or life-threatening attack)
- FBC; U&E
Px acute asthma attack still not improving. Next steps?
• Discuss patient with senior clinician and ICU team
• Consider IV magnesium sulphate 1.2–2 g over 20 minutes (unless already given)
• Senior clinician may consider use of IV β2
bronchodilator or IV aminophylline or
progression to mechanical ventilation
What is treatment given if patient is improving within 15-30 minutes of life threatening asthma?
- Oxygen to maintain SpO2 94–98%
- Prednisolone 40–50mg daily or IV hydrocortisone 100 mg 6 hourly
- Nebulised β2 bronchodilator with ipratropium 4–6 hourly
Side effects of salbutamol
tachycardia, arrhythmias, tremor, K+ reduced
What drug class do Hydrocortisone and prednisolone belong do? What do they do?
Steroids, reduce inflammation.
ACUTE ASTHMA: IF PATIENT NOT IMPROVING AFTER 15–30 MINUTES?
• Continue oxygen and steroids
• Use continuous nebulisation of salbutamol at 5–10 mg/hour if an appropriate nebuliser is available. Otherwise give nebulised salbutamol 5 mg every 15–30
minutes
• Continue ipratropium 0.5 mg 4–6 hourly until patient is improving
How must a patient with acute asthma be monitored?
Repeat measurement of PEF 15–30 minutes after starting treatment
• Oximetry: maintain SpO2 >94–98%
• Repeat blood gas measurements within 1 hour of starting treatment if:
- initial PaO2 <8 kPa (60 mmHg) unless subsequent SpO2
>92% or
- PaCO2 normal or raised or
- patient deteriorates
• Chart PEF before and after giving β2 bronchodilator and at least 4 times daily throughout hospital stay
What must you ensure before discharging patients from hospital?
Been on discharge medication for 12–24 hours and have had inhaler technique
checked and recorded
• PEF >75% of best or predicted and PEF diurnal variability <25% unless discharge is
agreed with respiratory physician
• Treatment with oral steroids (prednisolone 40–50 mg until recovery - minimum 5
days) and inhaled steroids in addition to bronchodilators
• Own PEF meter and written asthma action plan
• GP follow up arranged within 2 working days
• Follow-up appointment in respiratory clinic within 4 weeks
In acute asthma when do you transfer a patient to ICU?
Transfer to ICU accompanied by a doctor prepared to intubate if:
• Deteriorating PEF, worsening or persisting hypoxia, or hypercapnia
• Exhaustion, altered consciousness
• Poor respiratory effort or respiratory arrest
What is the only Ix you need for the immediate management of a px with life threatening asthma?
ABG
What are the blood gas markers of a life threatening attack?
• ‘Normal’ (4.6–6 kPa, 35–45 mmHg) PaCO2 • Severe hypoxia: PaO2 <8 kPa (60 mmHg) irrespective of treatment with oxygen • A low pH (or high H+)