Status asthmaticus: Difference between revisions

Jump to navigation Jump to search
No edit summary
Line 39: Line 39:
====General Physical Examination====
====General Physical Examination====
*Sit upright with arms extended to support the upper chest ('''tripod position''') that assist the use of accessory muscles of respiration
*Sit upright with arms extended to support the upper chest ('''tripod position''') that assist the use of accessory muscles of respiration
*[[Asthma pulmonary function test#Peak Expiratory Flow Rate|Peak flow rate]] is a simple bedside measurement of airway obstruction and a red zone indicates less than 50% of the usual or normal peak flow reading signifying severe airway obstruction.
*[[Asthma pulmonary function test#Peak Expiratory Flow Rate|Peak flow rate]] is a simple bedside measurement of airway obstruction and a '''red zone''' indicates less than 50% of the usual or normal peak flow reading signifying severe airway obstruction.


====Respiratory Examination====
====Respiratory Examination====
Line 59: Line 59:
*Level of consciousness ranges from lethargy, agitation to even [[loss of consciousness]] or [[seizure]], secondary to severe airway obstruction, [[hypoxia]] and carbon-di-oxide retention.
*Level of consciousness ranges from lethargy, agitation to even [[loss of consciousness]] or [[seizure]], secondary to severe airway obstruction, [[hypoxia]] and carbon-di-oxide retention.
*Unable to speak in full sentences
*Unable to speak in full sentences
===Laboratory Tests===
*Measurement of oxygen saturation by pulse oximetry may be useful to identify patients with acute severe asthma who may rapidly progress to [[respiratory failure]] and thereby require more intensive therapy.<ref name="pmid1121560">Overall JE (1975) [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=1121560 Rating session. Video taped interviews and BPRS ratings.] ''Psychopharmacol Bull'' 11 (1):15. PMID: [http://pubmed.gov/1121560 1121560]</ref>
*[[Arterial blood gas]] may reveal [[respiratory alkalosis]] that is consistent with the [[hypoxemia]] and/or [[hypercarbia]] secondary to significant [[hypoventilation]].
*CBC count may demonstrate an increase in [[white blood cell|peripheral WBCs]] secondary to the use of [[steroids]] and [[Bronchodilators|β-agonists]].
===Pulmonary Function Test===
[[Spirometry#Explanation of common test values in FVC tests|FEV1]] lower than 60% predicted is strongly suggestive of severe airway obstruction
===ECG===
The presence of [[supraventricular tachycardia]] on ECG should raise a suspicion of [[Bronchodilator#Theophylline|theophylline toxicity]]. 
===Imaging Modalities===
[[Asthma CT|High-resolution CT]] may reveal several structural changes related to small-airway disease including [[Bronchiectasis|cylindrical bronchiectasis]], bronchial wall thickening, and [[air trapping]].<ref name="pmid1094668">Robards VL, Lubin EN, Medlock TR (1975) [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=1094668 Renal transplantation and placement of ileal stoma.] ''Urology'' 5 (6):787-9. PMID: [http://pubmed.gov/1094668 1094668]</ref>


==References==
==References==

Revision as of 03:56, 27 September 2011

Template:DiseaseDisorder infobox

Asthma Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Asthma from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

Chest X Ray

CT

MRI

Other Imaging Findings

Other Diagnostic Studies

Pulmonary Function Test
Bronchial Challenge Test
Exhaled nitric oxide

Treatment

Emergency Management

Medical Therapy

Alternative and Complementary Medicine

Bronchial Thermoplasty

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Status asthmaticus On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Status asthmaticus

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Status asthmaticus

CDC on Status asthmaticus

Status asthmaticus in the news

Blogs on Status asthmaticus

Directions to Hospitals Treating Asthma

Risk calculators and risk factors for Status asthmaticus

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Lakshmi Gopalakrishnan, M.B.B.S. [2]

Overview

Status asthmaticus is an acute exacerbation of asthma that does not respond to standard bronchodilator and corticosteroid therapy. Symptoms include chest tightness, rapidly progressive dyspnea, non-productive cough and wheezing. Status asthmaticus if left untreated may result in severe bronchospasm, mucus plugging and rapidly develops acidosis and respiratory failure as a consequent of carbon di oxide retention and hypoxemia.

Epidemiology

Approximately 10% of the US population is affected by asthma with status asthmaticus requiring highest rates of hospitalization.[1]

Predisposing factors

  • Increase use of bronchodilator despite resistance,
  • Frequent exacerbations despite the use of corticosteroids,
  • Despite adhering to therapy, a peak flow rate of less than 10% from baseline,
  • Frequent hospitalization for acute attacks,
  • History of syncope or seizure during an acute asthmatic attack,
  • Oxygen saturation lower than 92% despite supplemental oxygen,
  • Airway obstruction is significantly reduced, resulting in severe impairment of air motion that leads to a silent chest with the absence of wheeze suggestive of an imminent respiratory arrest.

Diagnosis

History and Symptoms

Physical Examination

Vital Signs

General Physical Examination

  • Sit upright with arms extended to support the upper chest (tripod position) that assist the use of accessory muscles of respiration
  • Peak flow rate is a simple bedside measurement of airway obstruction and a red zone indicates less than 50% of the usual or normal peak flow reading signifying severe airway obstruction.

Respiratory Examination

Inspection
  • Use of accessory muscles of respiration correlates with the disease severity
  • Intercostal retractions
  • Paradoxical thoraco-abdominal breathing
Auscultation
  • High-pitch prolong polyphonic expiratory wheeze
  • Bilateral crackles
  • Air entry may or may not be reduced depending on the severity
  • Absence of wheeze, breath sounds secondary to severe airway obstruction may represent a silent chest which is an ominous sign of imminent respiratory failure.

Cardiovascular Examination

Progressive untreated airway obstruction and increased work of breathing eventually leads to worsening hypoxemia, hypercarbia and increased air trapping with compromised stroke volume that results in bradycardia, hypotension, hypoventilation and subsequent cardiorespiratory arrest.

Neurological Examination

  • Level of consciousness ranges from lethargy, agitation to even loss of consciousness or seizure, secondary to severe airway obstruction, hypoxia and carbon-di-oxide retention.
  • Unable to speak in full sentences

Laboratory Tests

  • Measurement of oxygen saturation by pulse oximetry may be useful to identify patients with acute severe asthma who may rapidly progress to respiratory failure and thereby require more intensive therapy.[2]

Pulmonary Function Test

FEV1 lower than 60% predicted is strongly suggestive of severe airway obstruction

ECG

The presence of supraventricular tachycardia on ECG should raise a suspicion of theophylline toxicity.

Imaging Modalities

High-resolution CT may reveal several structural changes related to small-airway disease including cylindrical bronchiectasis, bronchial wall thickening, and air trapping.[3]

References

  1. Gorelick M, Scribano PV, Stevens MW, Schultz T, Shults J (2008) Predicting need for hospitalization in acute pediatric asthma. Pediatr Emerg Care 24 (11):735-44. DOI:10.1097/PEC.0b013e31818c268f PMID: 18955910
  2. Overall JE (1975) Rating session. Video taped interviews and BPRS ratings. Psychopharmacol Bull 11 (1):15. PMID: 1121560
  3. Robards VL, Lubin EN, Medlock TR (1975) Renal transplantation and placement of ileal stoma. Urology 5 (6):787-9. PMID: 1094668


Template:WikiDoc Sources