Asthma

Asthma

A Chronic disease of the airways that may cause:

• Wheezing• Breathlessness• Chest tightness• Nighttime or early morning coughing

The bronchospasm characteristic of the acute asthmatic attack is typically reversible.

(برونکواسپاسم که با درمان بهبود یابد کاراکتریک حمله آسم حاد است)

It improves spontaneously or within minutes to hours of treatment

Asthma can exist by itself or coexist with:

• chronic bronchitis, or • emphysema, or • bronchiectasis

Symptoms/Chief Complaint

• Progressive dyspnea• Cough• Chest tightness• Wheezing/coughing

• The rapidly reversible airflow obstruction of asthma is mainly due to bronchial smooth muscle contraction

Focus of Therapy

• Pharmacologic manipulation of airway smooth muscle

• Do not overlook physiologic impairment caused by mucous production and mucosal edema

• Bronchospasm can be reversed in minutes• Airflow obstruction due to mucous plugging

and inflammatory changes in bronchial walls may not resolve for days/weeks - • may lead to atelectasis, infectious

bronchitis, pneumonitis

Asthma Triggers• Immunologic reaction• Viral respiratory/sinus infections• change in temperature/humidity• Drugs/Chemicals -

• aspirin, NSAIDS• Exercise• GE Reflux• Laughing/coughing• Environmental factors -

• strong odors, pollutants, dust, fumes

Patient Exam• Wheezing

• may be audible w/o stethoscope• ویز در آسم معموال بازدمی است (بازدم طوالنی تر است)• شدت ویز با شدت آسم ارتباطی ندارد

• Use of accessory muscles of inspiration• (... رتراکسیون بین دنده ای و)

• diaphragmatic fatigue• Paradoxical respirations

• (شکم و قفسه سینه عکس هم حرکت میکنند)• خستگی عضالت تنفسی و احتمال آپنه تنفسی• Reflect impending ventilatory failure

• Altered mental status -• lethargy, exhaustion, agitation, confusion

Patient Exam• Hyperrsonance to percussion

• decreased intensity of breath sounds

• prolongation of expiratory phase w or w/o wheezing

• The intensity of the wheeze may not correlate with the severity of airflow obstruction

• “quiet chest” - very severe airflow obstruction

Risk factors for death from asthma:

• Past history of sudden severe exacerbations

• Prior intubation for asthma

• Prior admission for asthma to an intensive care unit

• Two or more hospitalizations for asthma in the past year

• Three or more emergency care visits for asthma in the past year

• Hospitalization or emergency care visit for asthma within the past month

• Use of more than two canisters per month of inhaled short-acting 2-agonist

• Current use of systemic corticosteroids or recent withdrawal from systemic corticosteroids

• Difficulty perceiving airflow obstruction or its severity

• Comorbidity, as from cardiovascular diseases or chronic obstructive pulmonary disease

• Serious psychiatric illness or psychosocial problems

• Low socioeconomic status in urban residents

• Illicit drug use

Asthma Treatment

• Nebulized B-adrenergic drugs• Corticosteroids• Nebulized anticholinergics• Magnesium sulfate• Oxygen• Long acting beta-agonists• Inhaled steroids

Managing Asthma:

Indications of a severe attack:

• Breathless at rest(تنگی نفس در استراحت) • hunched forward(روی تخت خم شود) • talking in words rather than sentences (استفاده از کلمات بریده)

• Agitated• (Peak flow rate) PFR< 60% of normal in Spirometry

Treatment Goals of Severe Asthma

• Improve airway function rapidly• Avoid hypoxemia• Prevent respiratory failure and

death

Classifying Severity of Asthma Exacerbations

Symptoms Mild Moderate Severe

Breathlessness walking talking at rest

Position Can lie down Prefers sitting upright

Talks in Sentences Phrases Words

Alertness May be agitated Usually agitated Usually agitated


Signs Mild Moderate Severe

Pulsus Paradoxusنکته: اختالف فشارخون بین دم و بازدم بیمار =


Functional assessment Mild Moderate Severe

نکته: در اورژانس پالس اکسیمتری موجود است که میتوانیم بر اساس آن آسم را طبقه بندی کنیم

Respiratory Arrest Imminent

• Drowsy or confused

• Paradoxical thoracoabdominal movement

• Absent Wheeze

• Bradycardia

• Absence Pulsus paradoxus suggests respiratory muscle fatigue

Asthma Mimickers((تشخیص افتراقی های آسم

• Congestive heart failure ("cardiac asthma")• Upper airway obstruction• Aspiration of foreign body or gastric acid• Bronchogenic carcinoma with endobronchial

obstruction• Metastatic carcinoma with lymphangitic

metastasis• Sarcoidosis with endobronchial obstruction• Vocal cord dysfunction• Multiple pulmonary emboli (rare)

treatment of acute asthma

Goal in the ED• reverse airflow obstruction

rapidly by repetitive or continuous administration of inhaled 2-agonists

• ensure adequate oxygenation

• relieve inflammation

Initial Assessment

• History• physical examination

(auscultation use of accessory muscles, heart rate, respiratory rate)

• PEFR or FEV• oxygen saturation• other tests as indicated

Diagnosis

• Bedside spirometry • rapid, objective assessment ,guide to the effectiveness of

therapy.• The forced expiratory volume in 1 s (FEV1)• peak expiratory flow rate (PEFR)

• Sequential measurements

• management decisions

Pulse oximetry

• assessing oxygenation and monitoring oxygen saturation during treatment.

• ABG is not indicated in most patients with mild to moderate asthma exacerbation

را بدانیم)PCO2 نیاز نیست مگر اینکه بخواهیم سطح ABG(در همه بیماران آسمی

ABG

assess for hypoventilation with carbon dioxide retention and respiratory acidosis

• clinical evidence of severe attacks

• PEFR or FEV1 of less than 25 percent predicted

• With acute attacks, ventilation is stimulated, resulting in a decrease in partial pressure of carbon dioxide (PaCO2)• normal or slightly elevated PaCO2 (e.g., 42 mm Hg)

indicates extreme airway obstruction and fatigue and may herald the onset of acute ventilatory failure

Radiography

• clinical indication of a complication • pneumothorax, pneumomediastinum,

pneumonia, or other medical concern• one-third of asthma exacerbations

requiring admission, will demonstrate an abnormality on chest radiograph

CXR )) ها افتراقی تشخیص و تریگر پیداکردن برای مگر نیست کننده کمک

CBC

اندیکاسیون ندارد

• modest leukocytosis secondary to administration of:

B -agonist therapy or corticosteroid treatment

• In patients taking theophylline before ED presentation, a serum theophylline level

شود چک تئوفیلین سطح میگرفته تئوفیلین که بیماری

ECG

• Routine electrocardiogram is unnecessary which resolve with treatment:

1. right ventricular strain, or2. abnormal P waves, or3. nonspecific ST- and T-wave abnormalities

Older patients, especially those with coexisting heart disease, should have cardiac monitoring during treatment

(EKG میگیریم دارند قلبی ای زمینه بیماری که بیمارانی در) میگردند رفع آسم بادرمان که میشوند دیده اختصاصی غیر تغییرات روتین طور به زیرا

Impending or Actual Respiratory Arrest

• Intubation and mechanical ventilation with 100% 02

• Nebulized B2 agonist and anticholinergic

• Intravenous steroid

• Admit to ICU

اساس بر یا FEV1 درمانPEFR

FEV1 or PEFR >50%So2%≥90اکسیژن تا رساندن • بار در ساعت اول3 تا ß2-agonistاستنشاق • استرویید خوراکی (اگر درمانهای باال فورا جواب نداد یا اخیرا داروی استرویید خوراکی •

مصرف میکرده است)

دقیقه20 پاف هر 8, از اسپری سالبوتامول آگونیست (سالبوتامول) نداریم 2نکته: چون نبوالیزر بتا بار و سپس ارزیابی مجدد3میدهیم تا

FEV1 or PEFR <50%)Severe Exacerbation(

So2%≥90اکسیژن تا رساندن •دقیقه یا مداوم برای 20 و آنتی کولینرژیک با نبوالیزر هر ß2-agonistاستنشاق دوز زیاد •

مدت یک ساعت. استرویید خوراکی•

Repeat Assessment

• Symptoms. • physical examination. • PEFR. • 02 saturation. • other test as needed

Severe Exacerbation

Moderate Exacerbation

Incomplete Response

Good Response

Discharge Home

Poor Response

Poor Response

Poor Response

medications are used in the treatment of acute asthma

• adrenergic agonists• anticholinergics • glucocorticoids• Magnesium, heliox (mixture of helium

and oxygen), and ketamine may be considered when the aforementioned medications fail to relieve bronchospasm.

• Mast cell-stabilizing agents, methylxanthines, and leukotriene modifiers are currently reserved for maintenance therapy only

Adrenergic Agents

• Adrenergic receptors

• Stimulation of B 1-receptors increases rate and force of cardiac contraction and decreases small intestine motility and tone

• B2-adrenergic stimulation promotes bronchodilation, vasodilation, uterine relaxation, and skeletal muscle tremor

Adrenergic Agents

• stimulation of the enzyme adenyl cyclase, which converts intracellular adenosine triphosphate into cyclic adenosine monophosphate

• enhances the binding of intracellular calcium to cell membranes, reducing the myoplasmic calcium concentration, and results in relaxation of bronchial smooth muscle

• inhibit mediator release and promote mucociliary clearance.

side effect of B-adrenergic drugs:

• skeletal muscle tremor (most common)• nervousness, anxiety, • insomnia, headache, • hyperglycemia,• palpitations, tachycardia, and hypertension• potential cardiotoxicity(combination with

theophylline not significant problems)• Arrhythmias and evidence of myocardial

ischemia(rare)

Inhaled short-acting B-2 agonists

Albuterol • Nebulizer solution (5 mg/mL)

• 2.5–5.0 mg every 20 min for 3 doses• then 2.5–10 mg every 1–4 h as needed or

10–15 mg per h continuously• Only selective B-2 agonists are

recommended• for optimal delivery, dilute aerosols to

minimum of 4 mL at gas flow of 6–8 L per min

Albuterol

• (MDI) Meter Dose Inhalation (90μ/puff)

• 4–8 puffs every 20 min up to 4 h

• then every 1–4 h as needed

• As effective as nebulized therapy if patient is able to coordinate inhalation maneuver; use spacer/holding chamber


• Bitolterol • Nebulizer solution (2 mg/mL) • MDI (370 macg/puff)

• Pirbuterol • MDI (200 g/puff)


• Systemic (injected), B-2 agonists

• Epinephrine (1:1000 or 1 mg/mL)• 0.3–0.5 mg SC every 20 min for 3 doses

• Terbutaline (1 mg/mL)• 0.25 mg SC every 20 min for 3 doses

No proven advantage of systemic therapy over aerosol

Anticholinergics • potent bronchodilators in patients with asthma

and other forms of obstructive lung disease • anticholinergics affect large, central airways,

• whereas B-adrenergic drugs dilate smaller airways • competitively antagonize acetylcholine at the

postganglionic junction between the parasympathetic nerve terminal and effector cell

• blocks the bronchoconstriction induced by vagal cholinergic-mediated innervation to the larger central airways

• concentrations of cyclic guanosine monophosphate in airway smooth muscle are reduced,further promotin bronchodilation

Anticholinergics

Ipratropium bromide • Nebulizer solution (0.2 mg/mL)

• 0.5 mg every 30 min for 3 doses• then every 2–4 h as needed

• Should not be used as first-line therapy;• should be added to 2 agonist therapy; • may mix in same nebulizer with albuterol

• MDI (18 g/puff)• 4–8 puffs every 6–8 h

side effects

• dry mouth• Thirst• difficulty swallowing• Less commonly

• tachycardia, restlessness, irritability, confusion, difficulty in micturition, ileus, blurring of vision, or an increase in intraocular pressure

Corticosteroids

• highly effective drugs in asthma exacerbation

• one of the cornerstones of treatment• mechanism of action is unknown( مکانیسم فعالیت نامشخص

(است

• Restoring B-adrenergic responsiveness • reducing inflammation• The onset of anti-inflammatory effect is delayed at

least 4 to 8 h after intravenous or oral administration.

ساعت بعد از مصرف خوراکی یا وریدی, اثرات آن شروع میشود)8) تا 4

Corticosteroids

• administered within 1 h of arrival in the ED• reduces the need for hospitalization• prednisone 40 to 60 mg, oral• methylprednisolone 60 to 125 mg IV

• High-dose corticosteroid therapy offers no advantage

• Additional doses should be given every 4 to 6 h until significant subjective and objective improvements are achieved

• discharging all patients with mild persistent or more severe asthma on maintenance inhaled corticosteroids in addition to a burst of oral corticosteroid

Corticosteroids

• Prednisone• Methylprednisolone • Prednisolone

• 120–180 mg per d in 3 or 4 divided doses for 48 h,

• then 60–80 mg per d until FEV1, or PEFR reaches 70% of predicted or personal best

• For outpatient "burst," use 40–60 mg per d, for 3–10 d in adults

Theophylline• no longer considered a first-line treatment • in combination with inhaled B 2-adrenergic

drugs,• increase the toxicity, but not the efficacy, of

treatment• more sustained bronchodilator effect,

improving respiratory muscle endurance• improving resistance to fatigue• anti-inflammatory

side effects • nervousness, nausea, vomiting, anorexia, and

headache• At plasma levels greater than 30 g/mL, there

is a risk of seizures and cardiac arrhythmias.

magnesium sulfate

• acute, very severe asthma (i.e., FEV1 <25 percent predicted)

• The dose is 1 to 2 g IV over 30 min.

• Heliox, Ketamine, and Halothane • Mast Cell Modifiers • Leukotriene Modifiers

Mechanical Ventilation

• progressive hypercarbia and acidosis

• Exhausted• confused,

• does not relieve the airflow obstruction eliminates the work of breathing and enables the patient to rest while the airflow obstruction is resolved

• Direct oral intubation

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Asthma