severe acute asthma in children
DESCRIPTION
Basic principles of managing any child with severe acute asthma and life-threatening asthmaTRANSCRIPT
Acute Severe Asthma
Dr. Bernard Fiifi Brakatu
Outline
Pathogenesis
Pathophysiology
Trigger Factors
ER Management
PathogenesisGenetic Predisposition
Chronic Inflammation
Smooth muscle and nerve cell dysfunction
Pathophysiology
Trigger factors cause bronchial hyperactivity leading to bronchoconstriction, mucosal edema and increased mucus secretion.
Results in airway obstruction, decrease in lung compliance, alveolar hypoventilation, pulmonary vasoconstriction and decreased production of surfactant.
Hypercapnea, acidosis, respiratory failure may occur if it persists
Trigger Factors in Asthma
Viral Infections
Dusts and pollutants incl. cigarette smoke
Allergens – house dust mite, pollens, moulds, spores, animal dander and feathers, certain foods, etc
Exercise
Changes in weather patterns and cold air
Psychological factors eg. Stress and emotion
Classification –based on risk factors and
prognosis Transient Infant Wheezers- wheeze early in
life but no subseq. increased risk of developing persistent asthma. Risk factor is low lung function in early life that persists until adolescence
Atopic Asthma – Sx appear early in life but persist into childhood and adolescence. More likely to have +ve skin test to allergens, bronchial hyper-responsiveness to trigger factors and increased daily peak flow variability. Sxx are severe and deficits in lung function, tho absent immediately after birth, are present by the age of 6yrs
Non-atopic asthma – May have early or late onset of Sxx but are usually not skin test +ve to allergens by age 6.
Other atopic dxx are common eg. Eczema, vernal conjunctivitis and allergic rhinitis(Samter’s triad). Strong ass. with total serum IgE and Increased daily peak flow variability.
Clinical Classification
Mild, Infrecquent Asthma(75% of pts) –attacks occurring less than once a month
Frequent episodic asthma(20%) – more than one episode every week with symptom free intervals
Chronic Asthma(4%) – low grade wheeze present most days; wheeze with exertion, nocturnal cough and some limitation of physical activity
Severe Chronic Asthma(1%) – Sxx present everyday with stunting of growth and barrel chest deformity, and marked limitation of activity
ER Management Brief Hx:
time of onset of current exacerbationcurrent medications and allergiesrecent frequent use of beta2-agonistsrisk factors for severe, uncontrolled disease (e.g. ER visits, admissions to the hospital and ICU, and prior intubations)
Age of onset – poorer prognosis with earlier onset
Frequency of attacks
Prev or current atopic dermatitis/allergic rhinitis
Persistent nocturnal cough(cough-variant asthma)
Exposure to asthma triggers
Use of peak flow with home management respiratory score
PE Level of Consciousness, Ability to speak in full
sentences, color, pulse, blood pressure, shape of chest, FAN, Use of accessory muscles of resp, RR, AE, PN, BS, Rhonchi, Creps, etc
PEFR
Pulse oximetry
STOP THE PE AND PROCEED TO RESUSCITATE IF THERE IS: SILENT CHEST(imminent resp failure) or CEREBRAL HYPOXEMIA(Mental agitation, drowsiness and confusion)
Classification of Asthma Severity
Clinical Features
Mild Moderate Severe Life-threatening asthma
Mental Status Normal Might look agitated
Usually Agitated Drowsy of Confused
Activity Normal Activity, Exertional dyspnea
Decreased Activity or feeding(infant)
Decreased activity, infant stops feeding
Unable to eat
Speech Normal Speaks in phrases Speaks in words Unable to speak
Work of breathing Minimal intercostal retractions
Intercostal and substernal retractions
Signif. resp distress. FAN+, ICR+, SCR+ and paradoxical thoraco-abdominal movement
Marked resp distress at rest. FAN+, ICR+, SCR+ and paradoxical thoraco-abdominal movement
Chest Auscultation
Moderate wheeze Loud pan-expiratory and inspiratory wheeze
Wheezes might be audible without stethoscope
The chest is silent (absence of wheeze)
SpO2 on room Air >94% 91–94% 91–94% <90%
Peak flow vs Personal Best
>80% 60–80% best <60% Unable to perform the task or <33%
Life-threatening Asthma –
Silent chest, Cyanosis, Poor respiratory effort, Hypotension, bradycardia, Exhaustion, Confusion or drowsiness
•Acute Severe Asthma –
Unable to complete sentences in one breath; too breathless to talk or feed, Agitation, Accessory muscle use
• Pulse rate >140/min in children 2-5 years old; >125/min in children >5 years old
• Respiration >40 breaths/min in children 2-5 years old; >30 breaths/min in children >5 years old
Differentials
Severe Pneumonia
Cardiac Asthma(Acute LVF)
Acute Chest Syndrome
CCF
Loefler’s Syndrome
Principles of Treatment
Treat hypoxemia,
Give short-acting ß2-agonists,
Prescribe corticosteroids,
Assess treatment response, and
Consider other modalities of treatment.
Immediate Treatment
High flow O2 via face mask at 6-8L/min
Nebulize with 5mg Salbutamol(2.5mg in very young children) in 4mls of saline for 5-10min
Prednisolone 1-2mg/kg PO(max. 40mg)
If life-threatening – IV Aminophylline 1mg/kg/hr, IV Hydrocortisone 100mg(4mg/kg/dose) 6hrly, Add Ipratropium bromide 0.25mg(0.125 in younger children) to Neb Salbutamol
Rehydration – o/a excessive sweating, fluid loss and poor/lack of intake during acute episode. 3000mls/m2
Subsequent mngt
IF THE PT IS IMPROVING, CONTINUE:
High flow O2,
Prednisolone 1-2mg/kg dly(max. 40mg)
Nebulised Salbutamol 4hrly
IF PT IS NOT IMPROVING AFTER 30MIN:Continue O2 and steroids
Give Nebulised Salbutamol more frequently up to 30min
Add ipratropium to nebulizer and repeat 6hrly until improvement starts
IF PT STILL NOT IMPROVING, GIVE:
Aminophylline infusion(1mg/kg/hr)
Monitoring Treatment
Oxymetry : Maintain SpO2 >92%
Check PEF
Discharge Before discharging from hospital the pt:
Shd have been on discharge medications for 24hrs and have had inhaler technique checked recorded
If recorded PEF>75% predicted or best and PEF variability <25%
Treatment with soluble steroid tablets and inhaled steroid(Seretide/Symbicort) in addition to bronchodilators(Ventolin). MDIs are difficult to use in young children so include a spacer.
Nedocromil Sodium or Zafirlukast(Accolate) as prophylaxis
Educate mother on trigger factors and first aid before getting to hospital
Review within 4wks, and then every 3 to 6mnths
THANKS