Asthma Flashcards
Asthma
➢Chronic inflammatory disorder of the airways characterized by increase responsiveness of the ___________ tree to a variety of stimuli
➢This disorder causes recurrent episodes of
● _______, Breathlessness, Chest tightness, Cough (night and early a.m. ), Variable airflow obstruction that is REVERSIBLE
●Tachypnea, Prolonged _______ phase, Fatigue
- tracheobronchial
- wheezing
- expiratory
Pathophysiology of Asthma
➢Airway __________ and inflammation
➢Mediators include: all have been implicated as histologic mediators
➢ Eosinophils, mast cells, neutrophils, ________, basophils,T lymphs
➢Other probable mediators of acute __________
include: cytokines, interleukins, ________ acid metabolites (leukotrienes and prostaglandins),kinins, histamine, adenosine, and PAF
- hyper-responsiveness
- macrophages
- bronchoconstriction
- arachidonic
Pathophysiology of Asthma
➢Asthma creates airways that are:
●inflamed, ________, hypersensitive to irritant stimuli
➢ The degree of airway responsiveness and bronchoconstriction parallels the extent of __________
- edematous
* inflammation
Asthma: Alterations in PFTs/Lung Volumes
- Decreased ______
- extent of decrease reflects severity of ______ obstuction
- FEV1
* expiratory
Asthma: Blood Gas Alterations
- In mild to moderate asthma FEV1 >50% predicted – PaO2 and PaCO2 _____
- In fact, PaCO2 often decreased as a result of ______ (neural reflex to bronchoconstriction)
- With severe asthma (FEV1 less than 25%) - PaO2 may be less than 60mmHg and ______ may develop
- CXR = _______ of the lungs
- normal
- hyperventilation
- hypercarbia
- hyperinflation
Pharmacologic Management: Prophylactic Approach
Treat Underlying Inflammation
*Inhaled Corticosteroids: Decreases ______ and hyper-responsiveness
*Cromolyn
*Leukotriene _________
*Methylxanthines-phosphodiesterase inhibitors
- bronchial mucosal inflammation
* inhibitors
Pharmacologic Management: Rescue Approach - Bronchodilators
*Beta-2 Adrenergic Agonists – albuterol, ________
- B-2 receptor activation of adenylate cyclase with increased _____
concentrations & bronchodilation
- SNS side effects: tachycardia, dysrhythmias, _____ shifts
- terbutaline
- cAMP
- potassium
Pharmacologic Management: Rescue Approach - Bronchodilators (con’t)
- Anticholinergic Drugs – ________
- Block muscarinic receptors = _______
- Less effective than B-2 in asthmatics
- ipratropium
* bronchodilation
Pre-Induction
- Assess Breath Sounds
- ____ before and after bronchodilator therapy for major elective operations (especially FEV1)
- _______ should be >70%-80% expected or personal best prior to surgery
- FEV1/FVC less than ____% = mod/severe asthma
- CXR, ABG
- PFTs
- FEV1/FVC
- 50%
Pre-Induction (con’t)
➢________ – good choice (anxiety can precipitate bronchospasm)
➢Opioids: consider the respiratory depressant effect
➢H-2 antagonist: _________ receptors responsible for bronchoconstriction
➢Continue current asthma ________ into peri-op period
- benzodiazipines
- unopposed H-1
- medications
Peri-operative Prophylaxis of Bronchoconstriction
➢Pre-operative bronchodilators – _______ before induction
➢Pre-operative steroids
1. Inhaled – start ___ hours pre-op
2. IV - _________ 100mg Q 8 hrs on day of surgery if FEV1 less than 80% predicted or at risk for HPA suppression
- albuterol
- 48
- hydrocortisone
Asthma and Anesthesia
Anesthesia-
➢Consider regional techniques
➢GA should be designed to
- depress ______ reflexes, avoid hyperactivity, avoid
bronchoconstriction, avoid _______ release
- airway
* histamine
Induction and Maintenance in the Asthmatic Patient:
➢Blunt airway reflexes and bronchoconstriction response during airway instrumentation
- Regional Anesthesia a good option, IV induction: propofol & ______
best, avoid drug preparations with ______, IV opioids
●Consider _______ 1.5 mg/kg IV or intratracheal (LTA)
- ketamine
- metabisulfites
- lidocaine
Induction and Maintenance in the Asthmatic Patient
•High concentration of volatile agent ______ for bronchodilation and bronchial reflex inhibition (need a strong CV system)
•Sevoflurane and Halothane less _______ – less coughing to trigger bronchospasm
- > 1.5 MAC
* pungent
Induction and Maintenance in the Asthmatic Patient
➢Avoid NDMR that release ______
- _______, mivacurium, metacurium, d-tubo
➢Anticholinesterase drugs
- _______ O.K. if given with anticholinergic (glycopyrulate)
- histamine
- atracurium
- neostigmine
GA for asthma, what medications are attractive and not attractive – and why?
➢Induction agents
*Thiopental – not attractive as releases ______
*Ketamine – _______ (SNS stim) but also stimulates secretions
*Etomidate, propofol – attractive -no release histamine. Generic
propofol contains _____ – consider avoiding in the asthmatic.
- histamine
- bronchodilator
- sulfites
GA for asthma, what medications are attractive and not attractive – and why? (con’t)
➢Neuromuscular relaxant
- Avoid those that trigger ______ release (succs, curare,
mivacurium, atracurium – dose and speed of admin dependent)
➢Opioid
- Avoid drugs that stim histamine release (morphine). Fentanyl and
analogues are OK.
➢Consider avoiding ______ & other NSAIDs in the asthmatic.
- histamine
* ketorolac
Anesthesia Plan
➢Volatile anesthetics:
- All are potent bronchodilators however _____ and ____ irritate the
airways, especially during induction and/or emergence.
- Halothane is the classic volatile agent for the asthmatic but being
replaced by ________
- isoflurane & desflurane
* sevoflurane
Induction and Maintenance in the Asthmatic Patient
➢IV fluids – liberal hydration to decrease ______ of secretions
➢Intra-op bronchospasm – attach _______ MDI to T-piece of ETT
➢Smooth emergence – ETT promotes reflex _____ and a/w resistance
➢Deep extubation (in appropriate patients) &/or lidocaine 1-3mg/kg IV
- viscosity
- albuterol
- bronchoconstricion
Ventilation Goals in the Asthmatic Patient
➢Decreased RR to 8-10 bpm: need adequate exhalation times
➢Prolong ___ ratio: shorter inspir time compared to expir time
➢Increase ______ to maintain normal PaCO2 (within limits)
➢Tidal volume and inspiratory flow rate adjustments limited by excessive ________ pressures (___ cmH2O upper limit)
- I:E
- TV
- peak airway, 40
What is in the differential diagnosis of intraoperative wheezing?
➢Foreign body (gastric tube in the lung), Partially blocked/kinked ETT
➢Light anesthesia, _______
➢_________ intubation, Pneumothorax
➢Pulmonary ______, Pulmonary edema “cardiac asthma”
➢Acute exacerbation of asthma
- aspiration
- endobronchial
- embolus
Bronchospasm: If an episode of bronchospasm occurs during anesth
- Administer _____ , Deepen the level of anesthesia as with a VA or IV drugs, Administer ___ agonist
- In severe cases administer _____ IV (severe cases; infusion 2-8 mcg/min, subcutaneously 0.3-0.5 mg q20-30 min)
- Consider IV corticosteriods 1-2mg of cortisol
- Consider IV ________
- 100% O2
- B2
- epinepherine
- aminophylline
Avoid at all cost taking a patient to the OR who is actively __________, especially for an elective procedure!!!!!! AAHHH!!!!
*WHEEZING
Asthma: Review -> Chronic disease consisting of:
●Chronic airway _________
●Airway wall _________ in severe cases- increased airway epithelium, increased sub-mucosa, and increased smooth muscle
●Reversible expiratory flow _______ (bronchial hyperactivity)
●Degree of expiratory airflow obstruction dynamic – varies over time
- inflammation
- thickening
- obstruction
Asthma: Alterations in PFTs/Lung Volumes (con’t)
- During asthma attack FEV1 ______%: common
- _____ loop show charac. downward scooping of the expir limb
- less than 35%
* flow volume
