Management Of Acute Attack Of Asthma by Dr.Nadeem dated 17-01-2012

MANAGEMENT OF ACUTE ATTACK OF ASTHMA: 

MANAGEMENT OF ACUTE ATTACK OF ASTHMA Dr.Nadeem-Ur-Rasool DCH Trainee

Acute asthma treatment Pathophysiology: 

Acute asthma treatment Pathophysiology Bronchospasm Airway edema Mucous plugging Ventilation/perfusion mismatch Increased FRC Impaired diaphragm function Accessory respiratory muscle use

Assessment of Severity: 

Assessment of Severity Altered conciousness anxiety Restlessness Irritability Cyanosis Pulsus paradoxus >18mmHg Tachycardia Tachypnoea Silent chest

Initial assessment of the severity of an acute attack : 

Initial assessment of the severity of an acute attack Clinical features Mild Moderate Severe and life-threatening altered consciousness no no Yes increased accessory muscle use no some Marked talks in sentences phrases Words pulse rate less than 100/minute 100 to 200/minute more than 200/minute FEV1 (% personal best or predicted) more than 75% 50 to 75% less than 50% oximetry while breathing air (SpO 2 ) more than 95% 90 to 95% less than 90% hospital admission needed? no probably, especially if poor initial treatment response yes, consider intensive care unit

Aims Of treatment: 

Aims Of treatment Prevent death Relieve airway obstruction Relieve hypoxemia Restore patient's clinical condition and lung function to normal as soon as possible Maintain optimal lung function and prevent early relapse Plan avoidance of future relapses Develop an action plan in case of further exacerbations.

Therapeutic options in acute severe asthma: 

Therapeutic options in acute severe asthma Proven benefit Oxygen Short-acting inhaled β- agonists Systemic corticosteroids Ipratropium (ED only) Possible benefit Magnesium IV β- agonists Heliox Theophylline

Role of oxygen in acute asthma: 

Role of oxygen in acute asthma Most (if not all) patients with moderate to severe acute asthma are hypoxemic Low SaO2 is predictive of admission Oxygen acts as a bronchodilator Beta-agonists worsen hypoxemia Hypoxemia increases risk of β-agonist induced cardiovascular side-effects

β-agonists in acute asthma: 

β- agonists in acute asthma Inhaled SABAs are the initial drugs of choice for acute asthma Onset 2-5 minutes Up to 1/3 of patients may be poorly responsive at presentation Albuterol should be given frequently initially (every 20 min).

Optimizing Delivery of Inhaled β2- agonists: 

Optimizing Delivery of Inhaled β2- agonists MDIs Always use spacer/VHC Young children and infants - 5-6 tidal breaths Older children – slow, deep inspiration with breath retention • Nebulizers Flow rate of 8-10 LPM Total aerosol volume of 4-6 ml Mouthpiece preferred Facemask must fit tightly

Corticosteroids in asthma: 

Corticosteroids in asthma Reduce inflammatory cells and mediators in the airway Increase β2- adrenergic receptor expression Therapeutic benefits usually seen within 6-12 hrs Delivery can be IV or PO or inhaled Methyl- prednisolone or prednisone usually dosed at 1 mg/kg every 6-12 hr initially

Other therapies to consider: 

Other therapies to consider Nebulized ipratropium IV magnesium sulfate Inhaled helium/oxygen IV terbutaline IV theophylline ?

PowerPoint Presentation: 

Nebulized ipratropium is a useful adjunct to β 2- agonists in the ED. IV Magnesium improves pulmonary function in children with ASA. Intravenous fluids are rarely required and are reserved for the critically ill child The role of intravenous aminophylline is being debated. Rationale for Heliox in Acute Asthma. 80% Helium:20% Oxygen (or 70:30) Less dense, more viscous than RA Increases laminar flow, decreases turbulent flow Decreases work of breathing May improve delivery of aerosolized albuterol

What about antibiotics?: 

What about antibiotics? At least 70% of acute severe asthma exacerbations triggered by viral respiratory infections Bacterial infections that may trigger acute asthma are mycoplasma and sinusitis Antibiotics should not be used routinely in acute asthma

treatment of acute attacks of asthma: 

treatment of acute attacks of asthma Mild attack Moderate attack Severe attack oxygen therapy usually not necessary if available, to maintain SpO 2 above 95% yes, to maintain SpO 2 above 95% short-acting beta2 agonists salbutamol 100 micrograms pMDI (preferably via a spacer), 2 to 4 inhalations, 3- to 4-hourly OR terbutaline 500 micrograms DPI 1 to 2 inhalations (more than 8 years), 3- to 4-hourly OR salbutamol 2.5 mg (less than 6 years) to 5 mg (6 years or more) by nebulizer, 3- to 4-hourly. salbutamol 100 micrograms pMDI (preferably via a spacer) 6 to 12 inhalations. If initial response is inadequate, repeat every 20 minutes for 2 further doses, then 1- to 4-hourly thereafter OR terbutaline 500 micrograms DPI, 2 to 4 inhalations (more than 8 years). If initial response is inadequate, repeat every 20 minutes for 2 further doses, then 1- to 4-hourly thereafter OR salbutamol 5 mg by nebulizer, 3- to 4-hourly. If initial response is inadequate, repeat every 20 minutes for 2 further doses, then 1- to 4-hourly thereafter. salbutamol 5 mg by nebuliser driven by oxygen (at least 8 L/min) every 20 minutes for 3 doses or continuously. If nebuliser and oxygen are not readily available, administration should be by metered dose inhaler as outlined under 'Moderate attack'.

Cont…: 

Cont… ipratropium bromide (optional, in addition to short-acting beta 2 agonist) ipratropium bromide 20 micrograms pMDI (preferably via spacer) 1 inhalation (less than 6 years) or 2 inhalations (6 years or more) OR ipratropium bromide 250 micrograms by nebuliser , 4-hourly to a maximum of 3 doses. ipratropium bromide 250 micrograms by nebuliser driven by oxygen (at least 8 L/min) every 20 minutes for 3 doses. adrenaline for anaphylaxis or imminent cardio-respiratory arrest: adrenaline 0.3 mg (0.3 mL of 1:1000 ampoule) diluted to 10 mL total volume slowly IV, or (child greater than 30 kg: 0.3 mg ; child 30 kg or less: 0.15 mg) IM

Cont…: 

Cont… corticosteroids consider: prednisolone 1 mg/kg/day orally, to a maximum of 50 mg daily, for 3 days then cease abruptly without tapering. hydrocortisone 4 mg/kg (maximum 100 mg) IV, 6-hourly on day 1. The same dose of corticosteroid is usually given IV, 12-hourly on day 2, then reduced or converted to oral therapy as clinical state permits OR methylprednisolone 1 mg/kg (maximum 50 mg) IV, 6-hourly on day 1. The same dose of corticosteroid is usually given IV, 12-hourly on day 2, then reduced or converted to oral therapy as clinical state permits OR prednisolone 1 mg/kg/day orally, to a maximum of 50 mg daily, for 3 to 5 days then cease abruptly without tapering. magnesium sulfate if no good response to initial treatment, give: magnesium sulfate 25 to 100 mg/kg ( maximum 1.2 to 2 g) IV, over 20 minutes

Cont…: 

Cont… hospital admission usually not necessary often necessary yes; HDU or ICU admission further management consider chest X-ray if persistent focal signs after bronchodilator chest X-ray if persistent focal signs after bronchodilator monitor for hypokalaemia may require assisted ventilation

Initial Monitoring: 

Initial Monitoring Pulse oxymetry PEFR (best of three ) Pulse, BP RR Clinical judgement : Cyanosis Use of accessory muscles Stridor diaphoresis Blood gasses

PowerPoint Presentation: 

Acute severe asthma 1.Oxgen 2.B2 agonist plus IB 3. Steroids No improvement IV magnesium sulphate No improvement ICU admission for IV salbutamol or IV aminophyllin Intubation plus ventilation Add Ketamine infusion Use muscle relaxant No improvement Inhalation gas HFOV ? ECMO? No improvement Duration of treatment + 1 hour allowed before next step Risk factors plus danger signs Long term management Improvement

D / D: 

D / D Cystic fibrosis Primary ciliary dyskinesia Bronchiolitis obliterans Congenital or acquired airway abnormalities Extrinsic allergic alveolitis ; Inhaled foreign body; Gastro- oesophageal reflux; Vocal cord dysfunction; Hyperventilation/panic disorder