Exam 4 Obstructive lung disease part I Flashcards
____ contribute to the risk of perioperative pulmonary complications
Obstructive respiratory diseases
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- ____ complications play an important role in determining long-term mortality after surgery
- Patient optimization prior to surgery can significantly decrease the incidence of these complications
- Pulmonary
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Obstructive respiratory diseases can be divided into 4 groups regarding their influence on anesthetic management:
- Acute upper respiratory tract infection (URI)
- Asthma
- Chronic obstructive pulmonary disease (COPD)
- Miscellaneous respiratory disorders
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Acute upper respiratory tract infection
- Ages ____ experience the “common cold” at a rate of 19% per year
- Ages ____ experience it at a rate of 16% per year
- Ages 25-44 experience the “common cold” at a rate of 19% per year
- Ages 45-65experience it at a rate of 16% per year
Consequently, a fraction of scheduled surgery pts will have an active URI
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Infectious (viral or bacterial) nasopharyngitis accounts for ̴____% of all URIs
95%
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Most common responsible viral pathogens of acute URI’s
- rhinovirus
- coronavirus
- influenza virus
- parainfluenza virus, and
- respiratory syncytial virus (RSV)
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Noninfectious nasopharyngitis can be ____ or ____ in origin
- allergic or vasomotor
Diagnosis is usually based on clinical signs and symptoms
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____ and ____ lack sensitivity, and are time and cost consuming
making them impractical in a busy clinical setting
Viral cultures & lab tests
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- Most studies on the effects of URI involve pediatric patients
- Children with URI’s are at much higher risk of perioperative respiratory adverse events such as:
- transient hypoxemia
- laryngospasm
- breath holding, and
- coughing
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- Data on adults with URI’s undergoing anesthesia is limited
- A pt who has had a URI for ____ and is stable or improving can be safely managed without postponing surgery
weeks
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If surgery is delayed, pts should not be rescheduled within ____ weeks as studies indicate that airway hyperreactivity may persist for that duration
6
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- The COLDS scoring system is used to determine risk of proceeding with surgery
- COLDS takes into account what?
- current sx’s
- onset of symptoms (higher risk w/n 2 weeks)
- presence of lung disease
- airway device (higher risk with ETT)
- surgery (higher risk with major airway surgery)
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Anesthetic management of pts w/URI’s should include:
- adequate hydration
- reducing secretions
- limiting manipulation of the sensitive airway
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Acute URI
- Nebulized or topical local anesthetic on the vocal cords may reduce ____
- Use of a LMA rather than an ETT may reduce the risk of ____
- Considerations for induction and maintenance are similar to those with ____
- When there are no contraindications, ____ may result in smoother emergence
- upper airway sensitivity
- laryngospasm
- asthma
- deep extubation
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Adverse respiratory events in pts with URIs include:
- bronchospasm
- laryngospasm
- airway obstruction
- postintubation croup
- desaturation
- atelectasis
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____ and ____ hypoxemia are common in acute URI and amenable to treatment with supplemental O2
Intraoperative and postoperative
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symptoms of acute respiratory infection vs influenza
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what disease has chronic inflammation of the mucosa of the lower airways? and is an episodic disease with acute exacerbations and asymptomatic periods?
Asthma
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In Asthma:
- Activation of the inflammatory cascade leads to infiltration of the ____ with eosinophils, neutrophils, mast cells, T cells, B cells, and leukotrienes
- This results in ____, especially in the bronchi
- There is also ____ that leads to thickening of the basement membrane and smooth muscle mass
- airway mucosa
- airway edema
- airway remodeling
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The main inflammatory mediators implicated in asthma include:
- histamine
- prostaglandin D2
- leukotrienes
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What are asthma provoking stimulators?
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symptoms of asthma include:
- expiratory wheezing
- productive or nonproductive cough
- dyspnea
- chest tightness that may lead to air hunger
- eosinophilia
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Most asthma attacks are short lived, lasting how long?
minutes to hours
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pt’s can experience periods of daily airway obstruction, ranging from ____ to ____
mild to severe
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what is status asthmaticus?
dangerous, life-threatening bronchospasm that persists despite treatment
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When the history is obtained from an asthma pt, attention should focus on:
- previous intubations
- ICU admission
- 2+ hospitalizations for asthma in the past year
- the presence of coexisting diseases
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- Diagnosis of asthma d/o clinical history, symptoms, and objective measurements of airway obstruction
- Asthma is diagnosed when a pt reports ____, ____, or ____ and demonstrates airflow obstruction on PFT that is at least partially reversible with ____
- wheezing, chest tightness, or SOB
- bronchodilators
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Classification of asthma severity depends on:
- the symptoms
- PFTs
- medication usage
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what is the most clinically usefull spirometric test of lung function?
- FEV1
- FVC
- FEV1/FVC ratio
- maximum voluntary ventilation (MVV)
- diffusing capacity
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what are direct measures of the severity of expiratory obstruction?
- Forced expiratory volume in 1 second (FEV1)
- forced expiratory flow (FEF)
- midexpiratory phase flow
These measurements can be used to assess the severity of an asthma attack
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The typical symptomatic asthmatic pt who comes to the hospital has an FEV1 of what?
< 35%
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how wil flow volume loop look like with asthmatic pt?
Flow-volume loops show a downward scooping of the expiratory limb of the loop
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During moderate or severe asthma attacks, what happens to FRC and TLC?
the functional residual capacity (FRC) may increase substantially, but total lung capacity (TLC) usually remains normal
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in asthma is diffusing lung capacity for carbon monoxide changed?
Diffusing lung capacity for carbon monoxide is not changed
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asthma
- In pts with ____ obstruction, relief of obstruction after a bronchodilator suggests the dx ofasthma
- Abnormalities in PFTs may persist for several days after an attack despite the absence of ____
- Since asthma is an episodic illness, its diagnosis may be suspected even w/ normal ____
- expiratory obstruction
- symptoms
- PFT results
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What is happening in graph B compared to A
B= bronchospasm. FEV1 < 80% of VC
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how does a volume flow loop look like in obstructive vs restrictive diease?
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with mild asthma how will abg look?
Mild asthma is usually accompanied by a normal PaO2 and PaCO2
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During an attack, tachypnea and hyperventilation is caused by ____ not hypoxemia
neural reflexes of the lungs,
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what are the most common ABG findings of symptomaticasthma
Hypocarbia and respiratory alkalosis
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- As the severity of expiratory obstruction increases, the associated ventilation/perfusion mismatching may result in a PaO2 of < ____ mmHg
- The PaCO2 is likely to increase when the FEV1 is < ____% of predicted
- < 60mmhg
- < 25%
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in asthma fatigue of the skeletal muscles necessary for breathing may contribute to the development of ____
hypercarbia
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- Pts w/severe asthma may demonstrate hyperinflation and hilar vascular congestion due to ____ and ____
- ____ can be helpful in determining the cause of an asthma exacerbation and ruling out other causes
- ____ may show signs of RV strain or ventricular irritability during an asthma attack
- mucous plugging and pulmonary HTN
- CXR’s
- EKG
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The differential diagnosis of asthma includes:
- viral tracheobronchitis
- sarcoidosis
- rheumatoid arthritis w/bronchitis
- extrinsic or intrinsic AW compression
- vocal cord dysfunction
- tracheal stenosis
- chronic bronchiti
- COPD
- and foreign body aspiration
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the aim of asthma treatment lie in controlling s/s and reducing exacerbations. What medications can be used?
- short acting inhaled β2 agonist
- daily inhaled corticosteroids
- inhaled muscarinic antagonists
- leukotriene modifiers
- mast cell stabilizers
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what is the 1st line of tx in pts with milde asthma?
short-acting inhaled β2 agonist.
This is only recommended in those w/ < 2 exacerbations/month
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what do inhaled coritcosteroids do for asthma?
improve sx’s, reduce exacerbations and decrease risk of hospitalization
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if sx remain uncontrolled what can be added?
daily inhaled β2 agonist
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- ____ are reserved for severe asthma, uncontrolled with inhalational medications
- Studies show that ____ decreases use of long-term medications and may improve quality of life
- Systemic corticosteroids
- SQ immunotherapy
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____ is recently approved and the only nonpharmacologic tx for refractory asthma
Bronchial thermoplasty (BT)
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- BT uses bronchoscopy to deliver radiofrequency ablation of airway smooth muscles to all lung fields except the ____
- The procedure is performed in three sessions and uses intense heat, which carries a risk of ____
- right middle lobe
- airway fire
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- Loss of airway smooth muscle mass is thought to reduce____
- Serial PFTs can be useful for?
- When the FEV1 improves to about ____% of normal, pts usually have minimal or no symptoms
- bronchoconstriction
- monitoring response to treatment
- 50%
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what disease happens when bronchospasm doesn’t resolve despite usual treatmenat and is considered life threatening
Acute severe asthma
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how do you treat acute severe asthma?
Emergency tx consists of:
* high-dose, short-acting β2 agonists
* systemic corticosteroids
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INH β2 agonistscan be administered every ____ minfor several doses w/o adverse hemodynamic effects, although pts may experience unpleasant sensations resulting from ____
- 15-20 min
- adrenergic overstimulation
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- IV corticosteroids are administered early, why?
- The 2 corticosteroids most commonly used:
- because onset takes several hours
- hydrocortisone & methylprednisone
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- in acute severe asthma Supplemental O2 is given to help maintain O2 saturation >____%
- Other drugs used in more severe cases include:
- > 90%
- magnesium and oral leukotriene inhibitors
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What is the treatment for acute severe asthma?
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- Bronchospasm has been reported in ____% of asthmatics undergoing GA
- Risk of bronchospasm is correlated with ____ and ____.
- 0.2-4.2%
- the type of surgery (higher with upper abdominal and oncologic surgery) and how recent the last attack occurred
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GA mechanisms that increase airway resistance:
- depression of cough reflex
- impairment of mucociliary function
- reduction of palatopharyngeal muscle tone
- depression of diaphragmatic function
- increased fluid in the airway wall
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Other factors that play a role in bronchospasm include:
- airway stimulation by intubation
- PNS activation
- and/or release of neurotransmitters such as substance P and neurokinins
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Preop evaluation of pts with asthma requires an assessment of:
- disease severity
- effectiveness of current tx
- and the need for additional therapy before surgery
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what should we make note of when assessing asthmatic pt?
- history of symptom control
- frequency of exacerbations
- need for hospitalization or intubation
- previous anesthesia tolerance
- Physicalappearance
- use of accessory muscles
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why is auscultation of the chest important when assessing an asthmatic?
to detect wheezing or crepitations
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what often mirror the degree of airway inflammation?
eosinophil counts
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Asthma Preop Assessment
- Preop PFTs (esp FEV1) before and after bronchodilator may be indicated
- A reduction in FEV1 or forced vital capacity (FVC) to < ____% of predicted, and/orFEV1:FVC ratio < ____% of predicted, is a risk for periop respiratory complications
- < 70%
- < 65%
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