Presentation on theme: "STATUS ASTHMATICUS Sigrid Hahn, MD Andy Jagoda, MD, FACEP Department of Emergency Medicine Mount Sinai School of Medicine New York, New York."— Presentation transcript:
STATUS ASTHMATICUS Sigrid Hahn, MD Andy Jagoda, MD, FACEP Department of Emergency Medicine Mount Sinai School of Medicine New York, New York
Status Asthmaticus: A Case Study 35 year old male with a week of progressive difficulty breathing Using albuterol inhaler every hour, ran out several days prior to presentation Multiple hospitalizations with two intubations PMH: none Meds: albuterol inhaler Smokes “a few cigarettes” per day
Status Asthmaticus: A Case Study BP 150/90, P 120, RR 28; pulse oximetry 92% Alert, speaking in clipped sentences; sitting upright and appearing very anxious Lungs: severe inspiratory and expiratory wheezing, minimal air movement Heart: tachycardic CXR hyperinflation, no pneumothorax
Indicators of Severe Asthma Anxious & diaphoretic appearance, upright position Breathlessness at rest and inability to speak in full sentences PaCO 2 normal or increased PEFR < 150 L/min or <50% predicted Pulse oximetry < 91% on room air Tachycardia (HR>120) and tachypnea (RR>30) Expert Panel Report 2: Guidelines for the diagnosis and management of asthma. National Institute of Health- National Heart, Lung and Blood Institute 1997; NIH publication number 97-4051
Approach to Severe Asthma Reverse bronchoconstriction Treat airway inflammation Correct hypoxemia Consider differential diagnosis Monitor for complications Pneumothorax Hypotension
In the management of a severe asthma exacerbation… How should beta-agonists be administered? Do anti-cholinergics have a role? Does aminophylline have a role? Does magnesium have a role? Should heliox be used? Does ketamine have a role? Should non-invasive ventilation be used? What should the ventilator settings be if the patient is intubated?
How should beta-agonists be administered? Inhaled -agonists are the treatment of choice In a small trial, there was no significant difference in response to delivery by nebulization, MDIs with spacers, or inhaled powder Raimondi AC et al. Chest 1997 Jul; 112:24-28 The optimal dose of inhaled -agonists varies among patients; dose should be titrated to effect Continuous treatments have been shown to be safe in patients with underlying cardiac disease Olshaker et al. Am J Emerg Med 1993;11:131 Olshaker et al. Am J Emerg Med 1993;11:131
If the patient is unable to tolerate inhaled -agonists … SC -agonists are an alternative to inhaled -agonists A randomized trial compared SC epinephrine 0.3-0.5 mg with SC terbutaline 0.25-0.5 mg Patients 18-64 years old Similar increases in PEFR and FEV at 5 and 15 minutes No difference in heart rate or blood pressure Continuous ECG revealed no dysrhythmias Spiteri: Subcutaneous adrenaline versus terbutaline in the treatment of acute severe asthma. Thorax 1988; 43:19-23
Should IV -agonist therapy be used? Meta-analysis evaluated 9 RCTs comparing IV - agonists in addition to, or instead of, inhaled -agonists in severe asthma in adults No significant differences were found in multiple outcome measures between the two groups If the patient can tolerate inhaled -agonists, there is no evidence to support the use of IV -agonists Travers et al. The Cochrane Library, Issue 3, 2003. Small trial found a benefit of IV -agonists in children Browne et al. Lancet 1997; 349: 301-305.
All patients with a severe asthma exacerbation should receive steroids 60 – 125 mg IV methylprednisolone 40-60 mg PO prednisone
Should anticholinergics be used in addition to -agonists? Multiple doses of inhaled ipratropium bromide in addition to -agonists lead to a significant improvement in pulmonary function tests Benefits most pronounced in those with FEV 1<30% Rodrigo. The Role of Anticholinergics in Acute Asthma Treatment- An Evidence-Based evaluation. Chest 2002; 121.1977-87.
Is there a role for IV aminophylline? Multiple theoretically beneficial effects Cochrane review included 15 trials and found no benefit over -agonists alone in PFTs or admission rates, even in severe asthma Increase in adverse effects (palpitations, vomiting) Parameswaran et al. The Cochrane Library, Issue 3, 2003 No studies compare outcome in patients with severe asthma who are unable to tolerate inhaled -agonists There is no evidence supporting its use
Is there a role for IV magnesium? Smooth muscle relaxation (bronchodilation) 2 gm of MgSO4 is safe and beneficial in patients with severe acute asthma exacerbations (FEV1<25% predicted) Rowe. Magnesium sulfate for treating exacerbations of acute asthma in the emergency room (Cochrane Review) The Cochrane Library. Issue 3, 2003.
What is heliox? Helium/Oxygen mixture Laminar flow reduces the resistance associated turbulent airflow in more proximal airways Allows greater oxygen delivery during inspiration Reduced work of breathing
Should heliox be used in severe asthma? Review found no improvement in PFTs regardless of heliox mixture or severity of disease Heliox-driven nebulizers were associated with a non-significant improvement in PFTs at one hour Rodrigo. Chest 2003; 123: 891-896. Rodrigo. The Cochrane Library. Issue 3, 2003
Does IV ketamine improve outcome? Ketamine is a bronchodilator, potentiates catecholamines 44 consecutive patients with severe asthma attacks received IV ketamine (0.1 mg/kg bolus and 0.5 mg/kg/hour infusion) for 3 hours Ketamine was used in conjunction with other standard therapies No difference in PEFR or hospital admission Howton. Randomized, double-blind, placebo-controlled trial of IV ketamine in acute asthma. Annals of Emergency Medicine. 27(2). 1996.
Does noninvasive ventilation improve outcome? BiPAP can reduce work of breathing, reduce bronchoconstriction and offset intrinsic PEEP Small trial used BiPAP in 30 patients with severe asthma after one neb in the ED Excluded patients with hypotension, Osat < 90%, depressed mental status, need for emergent intubation BiPAP was interrupted for short periods to deliver nebulized albuterol Significant improvement in PFTs Soroksky et al. A Pilot Prospective, RCT of BiPAP in Acute Asthma Attack. Chest 2003. 123: 1018-1025.
Who should be intubated? Decision should be based on clinical deterioration (altered mental status, respiratory fatigue) Neither hypoxia nor hypercarbia are absolute indications for intubation
Rapid Sequence Intubation in the Asthmatic Oxygenate Premedicate Lidocaine Glycopyrollate or atropine Induction with ketamine Paralysis with succinylcholine Intubation with large ETT
Mechanical Ventilation in Asthma Volume cycled ventilation FiO 2 1.0 Rate 8-10 I:E 1:4 or 1:5 V T 5-7 cc/kg PEEP 0 Maintain peak pressures < 45 cm H 2 0, plateau pressure < 30 cm H20
If peak pressures remain > 45 mm Hg… Evaluate for pneumothorax Ensure sedation & paralysis Allow hypercapnea (up to 80 mmHg) Consider pressure-controlled ventilation
Complications of Mechanical Ventilation Hypotension Barotrauma
CONCLUSIONS Beta-agonists are first line therapy Aminophylline does not have a role in the management of acute asthma Anticholinergics and magnesium may improve PFTs in severe asthma Consider using noninvasive ventilation Intubation is based on clinical status, not on numbers Ventilator management is based on permissive hypercapnea