Bronchospasm:%20successful%20management - PowerPoint PPT Presentation

About This Presentation
Title:

Bronchospasm:%20successful%20management

Description:

Many cases of severe bronchospasm do not have pre-existing history of bronchospastic disease. ... In-line manometer is not helpful! Resistor btw alveoli and circuit. ... – PowerPoint PPT presentation

Number of Views:631
Avg rating:3.0/5.0
Slides: 33
Provided by: chihpe
Category:

less

Transcript and Presenter's Notes

Title: Bronchospasm:%20successful%20management


1
Bronchospasmsuccessful management
  • Presented by R1???
  • supervised by VS???

2
Bronchospasm
  • Many cases of severe bronchospasm do not have
    pre-existing history of bronchospastic disease.
  • Very few asthma patients have adverse outcome in
    the perioperative period.
  • Routine pre-op PFT would be expensive and
    time-consuming.

3
Preoperative considerations
  • Pathophysiology of bronchospasmSmooth muscle
    contraction.Exaggerated bronchoconstrictor
    response to trigger - airway edema , increased
    secretions, smooth muscle contraction. Airway
    inflammation increases bronchial
    hyperresponsiveness.

4
Preoperative considerations
  • Role of recent infectionUpper airway viral
    infection, especially influenza, increased airway
    reactivity.Exacerbation of asthma.

5
Preoperative considerations
  • For asthma recent course of disease, Tx
  • For COPD stop smoking, infection control
    chest physiotherapy, steroid.

6
NIH recommendation
  • Evaluate the patients asthma over the past half
    year.
  • Improve lung function to predicted values before
    surgery, possibly with short course of oral
    steroids.
  • Give patients who have received steroids for
    longer than 2 weeks 100 mg hydrocortisone q8h iv.
    Taper within 24hrs.

7
Medications
8
Beta-adrenergic agonists
  • Both acute and chronic treatment.
  • Safety underestimated by anesthesiologists.
  • Inhaled beta2-agonists

9
Aminophylline
  • Bronchodilating action.
  • Does not add to the therapeutic effects of
    beta-adrenergic agonist.
  • Does not provide bronchodilation in dogs
    anesthetised with halothane.
  • Prophylaxis of acute attacks in chronic
    asthmatics.

10
Aminophylline
  • Prevent of nighttime bronchospasm episode.
  • Mucociliary clearance and diaphragmatic
    contraction.
  • Very low toxic/therapeutic index.

11
Steroids
  • Onset of benefit within few hours.
  • Useful as pre-op medication in patients with
    moderate to severe asthma.
  • One day high dose steroid doesnt affect wound
    healing and wound infection.
  • Inhalation steroids, MDI preparation.

12
Choice of Anesthesia
13
RA vs general vs LMA
  • Instrumentation of airway is the main trigger for
    wheezing during anesthesia.
  • LMA cause less airway resistance increase than
    ETT.
  • RA is ideal for reactive airway disease.
  • Sympathetic block , bronchospasm?

14
Induction agents
  • Thiopental rarely cause bronchospasm, but light
    anesthesia.
  • Ketamine produce bronchial smooth muscle
    relaxation.
  • Lidocaine 1-3 min before intubation prevents
    reflex bronchoconstriction, direct airway spray
    doesnt.
  • propofol induction 2.5 mg/kg .

15
Inhalation agents
  • Halothane vs isoflurane.
  • Mask induction less pungency , less cough
    response.
  • Intubaton sevoflurane is as effective as
    halothane , more effective than isoflurane.

16
Analysis of a bronchospastic crisis
17
The manifestation
  • Wheezing
  • Increase peak inflation pressure
  • Decrease exhaled tidal volume
  • Slow rising wave form on capnograph
  • Desaturation

18
Why do peak airway pressure rise?
  • Airway constrict, increase resistance.
  • Coughing and bucking.
  • Secretion and mucosal engorgement.
  • Air-trapping in severe case over-distension and
    less compliant.

19
What is auto-PEEP?
  • Airway resistance increase gtlonger inspiratory
    time gtshorter exp timeairway
    compressiongtincomplete exhalation.
  • In-line manometer is not helpful!
  • Resistor btw alveoli and circuit.
  • Patients with marginal volume status, decrease
    venous return and hypotension.

20
Why desaturate?
  • Secretion and spasm result in airway closure and
    underventilation of perfused area.
  • Inadequate perfusion or just falsely low reading
    due to hypotension.

21
Keep in mind!!
22
If low saturation is accompanied by hypotension,
trying to treat the low saturation with PEEP
could just make things worse!!
23
Why does pCO2 go up and ETCO2 go down?
  • Overdistension of some lung units,
    underventilation of others.
  • Overdistended alveoli may not be perfused well,
    especially in hypotension, large dead space.
  • Increase in V/Q mismatch.

24
Why does pCO2 go up and ETCO2 go down?
  • Overall minute ventilation declines as airway
    pressure rise.
  • Large compressible volume in circuit(7-10ml/cmH2O
    ).
  • Inability of our ventilator to maintain flow.
  • Changing to more powerful ICU type ventilator.

25
Responding to the crisis
26
Think before you do!
  • Obstruction of the ET tube from kinking,
    secretion, or an overinflated balloon.
  • Endobronchial intubation.
  • Active expiratory efforts.
  • Pulmonary edema or embolism.
  • Pneumothorax.

27
Deepen anesthesia
  • Even hypotension, lower intrathoracic pressure
    and improve venous return.
  • Paralysis decrease respiratory impedance
    associated with bucking.
  • Choice of agent-Sevoflurane and Halothane

28
Dont spare the beta-2 agonists
  • Further bronchodilation.
  • Inhalation route is just as effective as parental
    therapy but less side effects.
  • Spacer devices deliver drug effectively, even via
    ET tube.
  • Drug with long duration-

29
Ketamine
  • Incremental dose.
  • A quick way to maintain BP.
  • Rapidly deepening anesthesia.
  • Avoiding problems of inhaled anesthetics
    delivering to a poor ventilated patient.

30
Bring in an ICU ventilator
  • Not design for patient of respiratory failure.
  • Too much compressible volume.
  • Major disadvantage of ICU ventilator gt shift to
    iv anesthetics.

31
Currently available beta-2 agonists in NTUH
  • Ventolin (Albuterol) , nebules . Ventodisk
  • Bricanyl (Terbutaline) MDI, nebules.
  • Alupent (Metaproterenol), tab
  • Berotec (fenoterol) MDI , nebule, liquid.

32
The End
Write a Comment
User Comments (0)
About PowerShow.com