Post on 19-Jun-2020
transcript
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ACUTE SEVERE ASTHMA
Asso Prof Deepak Doshi FACEM, FCEM(UK), MPH, MRCS Ed(A&E), MRCS(Surgery), DCH, MS, MBBS
Director Medical Services Southwest Hospitals and Health Services, Roma.
Dr Deepak DoshiFACEM, FCEM(UK), DCH, MRCS A&E (Ed),
MRCS (Glasgow), MS, MBBS
Case
10 year old boy
SOB x 16 hours, worse in last 4 hours despite 2 hourly salbutamol puffs at home
Came by ambulance
Unable to speak full sentences
Increased efforts of resp
HR 160, RR 60, Sats 88% on 6 L, Temp 36.6
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What the next question?
Step wise management
O2 to 100% rebreather
Salbutamol neb - back to back
Atrovent - three times
Hydrocortisone 4mg/kg
call for help
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Further steps
Magnesium - Routes
Salbutamol infusion
BiPAP, high flow
Intubate
Aminophylline infusion
AIMS
Magnesium
Aminophylline
High flow and NIV
Ventilation strategies
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Mg – The wonder molecule!
Reversal of bronchospasm and decrease airway inflammation
Decreases uptake of calcium by bronchial smooth muscle
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Cochrane
Reduces hospitalisation in MODERATE and severe asthma
NO significant side effects
Authors' conclusionsIV MgSO4 may reduce the need for hospital admission in children presenting to the ED with moderate to severe exacerbations of asthma
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Practical maths 2.47 g in 5 ml vial
10 mmol in 5 ml vial = 1ml equals 2 mmol
0.2 mmol/kg
10 year child : 28 kg weight = 5.6 mmol = 2.8 ml in 100 ml N saline over 20 min
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Cochrane on Inhaled Mg
Limited studies
No side effects
Observed tingling sensation around mouth
500 mg in 2.5 ml normal saline given as nebulised
Repeat x 3
individual study results from three trials suggest possible improved pulmonary function in those with severe asthma exacerbations (FEV1 less than 50% predicted).
USA
NAEPP: National Asthma Education and Prevention Program (2012)
- IV Mg in children - Neb Mg - Heliox (Evidence B) - Aminophylline – NOT recommended
(Evidence A)
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GINA - GENEVA
GINA: Global Initiative for Asthma
- IV Mg - children who fail to respond and FEV1 <60% after 1 hr of care
- Neb Mg : (Evidence A) - Aminophylline in ICU settings
Practical maths
50 mg/kg or 0.2 mmol/kg
1ml = 500 mg
10 kg child = 1 ml solution = 500 mg = 2 mmol
20 kg child = 2 ml solution
30 kg child = 3 ml solution
Magnesium sulfate concentrated : Ampoule contains 2.465 g/5 mL (49.3%) of magnesium sulfate (or 493 mg/mL).1
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Aminophylline
Mitra AD et al 2009 Cochrane review
7 trials - 380 participants - FEV1 improved upto 24 hours - Length of hospital stay and mechanical
ventilation rates - same - Amino- 3 fold increased risk of vomiting
Adverse effects
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Aminophylline led to a three-fold increase in the risk of vomiting. There was no significant difference between treatment groups with regard to hypokalaemia, headaches, tremor, seizures, arrhythmias and deaths.
High Flow Oxygen
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Treatment of severe respiratory failure during status asthmaticus in children and adolescents using high flow oxygen and sodium bicarbonate.
Mansmann HC Jr. Abboud EM. McGeady SJ.
Annals of Allergy, Asthma, & Immunology. 78(1):69-73, 1997 Jan.
[Journal Article]
Case series : 6 patients – 9 episodes
Hypercarbia is well tolerated in children
High flow oxygen may prevent mechanical ventilation in some patients
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NIV
NIV
Murase , Tomii K, Chin K et al. The use of non-invasive ventilation for life threatening asthma: Changes in the need for intubation. Respirology. 15(4):714-20
May 2010
Retrospective 1999 to 2003 (48 pts) and
Then 2003 to 2008 (54 pts/57 events)
Rate of ETI dec from 18% to 3.5%
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Respir Care. 2010 May;55(5):536-43.
A prospective randomized controlled trial on the efficacy of noninvasive ventilation in severe acute asthma.
Gupta D, Nath A, Agarwal R, Behera D.
Source
Department of Pulmonary Medicine, Postgraduate Institute of Medical Education and Research, Sector 12, Chandigarh 160012, India.
53 patients
Improved FEV1
Decreased need for bronchodilators
Decreased ICU/Hospital stay
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Ventilation strategies
Auto PEEP - Reduce rate - Reduce tidal volume - Shorten the inspiratory time
Hyperinflation - Accept hypercapnia (permissive hypercapnia)
Breath stacking - Measure the end expiration volume (in some
machines)
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Avoid: Mophine and Atracurium (Histamine release)
Use : Ketamine - Propofol - Vec , Sux- Halothane and other gases
Caution: Aminophylline
Practical - Respiratory rate 10/min (or 25% less than
calculated for age) - Tidal volume 5-7 ml/kg - Oxygen 60% - PEEP 0-1 - Reverse/equalise I:E ratio