Status Asthamaticus
- 2. Objectives ● Definition of Asthma ● Definition of status Asthmaticus ● Pathophysiology of status Asthmaticus ● Causes of status Asthmaticus ● Clinical features ● Laboratory findings ● Treatment ● Prognosis
- 3. What is Asthma ? Chronic inflammatory disorder of the medium and small airways These airways are hypersensitive to certain “ triggers “ in the environment Intermittent and recurrent episodes of … -Wheezing -Shortness of breath -Chest tightness -Cough - night , early morning Condition is usually reversible
- 4. STATUS ASTHMATICUS IN CHILDREN Status Asthmaticus is a life threatening form of Asthma defined as “ a condition in which severe bronchoconstriction is unresponsive to the usual appropriate therapy with inhaled bronchodilators and anti-inflammatory agents that may progress to respiratory failure without prompt and aggressive intervention
- 5. Pathophysiology Life threatening asthma exacerbation are caused by severe Bronchospasm, airway inflammation, and increased mucus production..This pathophysiology results in increased pulmonary resistance, small airway collapse, and dynamic hyperinflation. Unlike during normal breathing, in status asthmaticus a child’s inspiratory muscle activity can persist through exhalation, significantly increasing respiratory muscle workload and fatigue.
- 6. ● Infants and children are at particular risk for respiratory failure from asthma due to several structural and mechanical features if their lungs ● They have less elastic recoil than adult lung , thicker airway walls leading to greater peripheral airway resistance for any degree of bronchoconstriction , fewer collateral channels of ventilation ● They have more compliant chest wall which can lead to increased work of breathing with airway obstruction.
- 7. Causes of Status Asthmaticus ● Infection (viral ) ● Anxiety ● Nebuliser abuse ● Dehydration ● Ingestion of aspirin and other NSAIDS ● Increased adrenergic blockade by B adrenergic blocker ingestion ● Non specific irritants may contribute to these episodes ● Poorly controlled asthma
- 8. Clinical features Red Flags signals - Dyspnea ( precluding speech ) - Accessory muscle use - Respiratory rate> 50/ mint - Heart rate > 140 / mint - Peak expiratory flow < 100l / mint - Hypercapnia - Excessive Diaphoresis
- 9. Life threatening features ( Should be admitted to PICU ) ● Cyanosis (with 60% oxygen ) ● Silent chest on auscultation ● Feeble respiratory effort ● Fatigue or exhaustion ● Agitation ● Reduced level of consciousness
- 10. Stage 1 of Status Asthmaticus relative compensation, as a result of resistance to sympathomimetics ● Frequent occurrence of prolonged attacks of asthma during the day, between attacks of breathing is not fully restored. ● Paroxysmal, painful, dry cough with sputum that is difficult to pass. ● Forced position (orthopnea), accelerated breathing (up to 40 in 1 min.) with the participation of auxiliary respiratory muscles. ● Breathing noises and dry wheezing can be heard in ● At percussion of the lungs – box sound (emphysema of the lungs), auscultation – "mosaic" breathing: in the lower lungs is not heard, in the upper – hard with a moderate amount of dry rales. ● As to the cardiovascular system – tachycardia up to 120 per minute ● Signs of central nervous system dysfunction - irritability, agitation, sometimes delirium, hallucinations.
- 11. Stage 2 of Status Asthmaticus- Stage of decompensation “ silent lung “ ● Extremely serious condition of patients. ● Sharply pronounced shortness of breath, shallow breathing, the patient "catches his breath." ● The position is forced, orthopnea. ● The skin is pale gray, moist. ● Periodically there is excitement, which is replaced by indifference. ● At auscultation of lungs – over all surface of lungs or on a big site of both lungs respiratory noises ("dumb lung", obturation of bronchioles and bronchial tubes) are not listened, only on a small site a small amount of rales can be heard. ● Cardiovascular system – pulse becomes more frequent (up to 140 per minute), weak filling, arrhythmias, hypotension, deaf heart tones, possible gallop rhythm.
- 12. Stage 3 of Status Asthmaticus- hypercapnic coma ● Unconscious patient, convulsions are possible before loss of consciousness. ● Spilled diffuse "red" cyanosis, cold sweat. ● Superficial, liquid, arrhythmic respiration (possibly Cheyne-Stokes respiration). ● At auscultation of lungs: absence of respiratory noises or their sharp weakening. ● Cardiovascular system: pulse filamentous, arrhythmic, blood pressure is sharply reduced or undetectable, collapse, deaf heart sounds, often gallop rhythm, possible ventricular fibrillation.
- 13. Laboratory Findings ● Complete blood picture ● Serum electrolytes ● ABGs ● Chest X-rays
- 14. Principles of Management The goal is to rapidly reverse the acute airflow obstruction with consequent relief of respiratory distress
- 15. “The longer it lasts , the worse it gets, and the worse it gets, the longer it lasts “
- 17. Initial Management ● Give high flow oxygen via tight fitting face mask to achieve saturations 94% or above ● Continuous monitoring of heart rate and oxygen saturation ● Continue nebulised Salbutamol therapy ● Ensure the child has received oral steroids (if oral steroids not tolerated, see IV hydrocortisone below) ● If a child is already on daily steroids increase the dose to 2 mg/kg (maximum 60mg) ● Children with clinical signs of dehydration should receive appropriate fluid resuscitation. ● Assess response to initial treatment
- 18. Do they have life threatening presentation If yes the commence nebulisers and proceed IV ● IV SALBUTAMOL( short acting beta 2 agonist) ● Salbutamol for injection comes in 2 concentrations: ● 500 micrograms in 1ml or 5mg in 5ml (1mg/ml). ● Loading Dose ● The LOADING dose of salbutamol is 15 micrograms/kg (maximum 250 micrograms) slow injection over 5-10 minutes. ● Infusion Dose ● INFUSION dose for salbutamol is 1-5micrograms/kg/min. Rates should be adjusted according to response.
- 19. If not responsive to initial therapy ● 1. Magnesium Sulphate (MgSO4) ● Cause bronchodilation by interference with calcium influx in bronchial smooth muscle . ● Drug dose ● The dose is 40mg/kg or 0.16mmols/kg (max. 2 grams) ● Hypotension and flushing may occur and should be anticipated with adequate fluid resuscitation ● 2. IV AMINOPHYLLINE ● Relaxation of airway smooth muscle by preventing degradation of cyclic guanosine monophosphate ● Drug dose ● The LOADING dose of aminophylline is 5mg/kg ● (5mls/kg of 1mg/ml solution) over 20 minutes (Maximum dose 500mg)..
- 21. Monitoring Requirements Children with severe asthma requiring intravenous therapy are high dependency (HDU) patients requiring close monitoring. ● Continuous ECG and saturation monitoring is necessary for patients on aminophylline and/or salbutamol infusions.
- 22. Non invasive ventilation ● Used to support patients with severe asthma exacerbations and help avoid the need for intubation and mechanical ventilation. ● Positive pressure ventilation may help avoid airway collapse during exhalation as well as to unload fatigue respiratory muscle ● Careful titration of inspiratory and expiratory pressure is Essential , to avoid complication of positive pressure Invasive ventilation ● If aggressive management fails , endotracheal intubation and mechanical ventilation may be necessary ● Patient presents with apnea or coma should be intubated immediately
- 24. Clinical Review ● Conscious Level. ● Oxygen saturations and oxygen requirement in litres/minute. ● Significant hypoxia (SpO2 <92%, or significant oxygen requirement >6l/min to maintain normal oxygen saturation) is indicative of severe asthma. ● Heart rate – Compare to normal range for age. ● Increasing tachycardia generally denotes worsening asthma but remember that B2agonists increase heart rate.
- 25. ● Blood Pressure ● Respiratory Rate – Compare to normal range for age. ● Posture / position of patient. ● Ability to talk in words, phrases or sentences ● Degree of Respiratory Distress / Use of accessory muscle and recession ● Air entry - including any clinical suspicion of pneumothorax or significant collapse and amount of wheezing including biphasic or silent chest
- 27. Prognosis ● Status Asthmaticus remains among the most common reasons for admission to the PICU ● High mortality rate ( 1%-3% ) ● 75% of patient admitted to PICU will be readmitted with a future exacerbation ● Careful outpatient follow -up of high risk population.