T4- Obstructive Lung Disease Flashcards
What is Bronchitis?
Increased mucus and inflammation
What is emphysema?
Destruction and enlargement of air spaces
What are the four groups of obstructive respiratory diseases regarding their influence on anesthetic management?
- Acute upper respiratory tract infection (URI)
- Asthma
- Chronic obstructive pulmonary disease (COPD)
- Miscellaneous respiratory disorders
How do obstructive respiratory diseases contribute to the risk of perioperative pulmonary complications?
Obstructive respiratory diseases contribute to the risk of perioperative pulmonary complications.
What role do pulmonary complications play in long-term postoperative mortality?
Pulmonary complications play a major role in long-term postoperative mortality.
How can the incidence of perioperative pulmonary complications be decreased?
Patient optimization prior to surgery can significantly decrease the incidence of these complications.
What is the annual rate of experiencing the “common cold” for individuals aged 25-44?
19% per year
What fraction of scheduled surgery patients may have an active upper respiratory infection (URI)?
Consequently, a fraction of scheduled surgery patients will have an active URI
What accounts for approximately 95% of all URIs?
Infectious nasopharyngitis
What are the most common associated viral pathogens with URIs?
Rhinovirus, coronavirus, influenza, parainfluenza, and respiratory syncytial virus (RSV).
How is the diagnosis of nasopharyngitis usually made?
Diagnosis is usually based on clinical symptoms
What are some perioperative respiratory adverse events associated with acute URI in pediatric patients?
Perioperative respiratory adverse events such as transient hypoxemia, laryngospasm, breath holding, and coughing.
How long should surgery be postponed if cancelled due to acute URI?
Surgery should not be rescheduled within 6 weeks
What factors does the COLDS scoring system take into account?
The COLDS scoring system takes into account current symptoms, onset of symptoms (higher risk within 2 weeks), presence of lung disease, airway device (endotracheal tube = higher risk), and type of surgery (major airway surgery = higher risk).
What are some components of anesthetic management for patients with acute URI?
Adequate hydration, reducing secretions, and limiting airway manipulation.
How might nebulized or topical local anesthetic on the vocal cords aid in anesthetic management?
It may reduce upper airway sensitivity.
How can the risk of laryngospasm be reduced in patients with acute URI?
Using a laryngeal mask airway (LMA) instead of an endotracheal tube (ETT).
What technique might be considered for smoother emergence in patients with acute URI, if there are no contraindications?
Deep extubation.
What are some adverse respiratory events associated with acute URI?
Bronchospasm, laryngospasm, airway obstruction, postintubation croup, desaturation, and atelectasis.
How can intraoperative and postoperative hypoxemia in patients with acute URI be managed?
They are common and treatable with supplemental oxygen.
What is asthma characterized by?
Asthma is characterized by chronic inflammation of the mucosa of the lower airways.
What is the result of activation of the inflammatory cascade in asthma?
Activation of the inflammatory cascade leads to infiltration of the airway mucosa with eosinophils, neutrophils, mast cells, T cells, B cells, and leukotrienes, resulting in airway edema, especially in the bronchi.
What are the main inflammatory mediators implicated in asthma?
Histamine, prostaglandin D2, and leukotrienes.
What are some asthma-provoking stimulators?
How is asthma characterized in terms of symptom presentation?
Asthma is an episodic disease with acute exacerbations and asymptomatic periods.
What are some common symptoms of asthma?
Symptoms include expiratory wheezing, productive or nonproductive cough, dyspnea, chest tightness that may lead to air hunger, and eosinophilia.
How long do most asthma attacks typically last?
Most attacks are short-lived, lasting minutes to hours.
What is “status asthmaticus”?
Status asthmaticus refers to dangerous, life-threatening bronchospasm that persists despite treatment.
What aspects of a patient’s history should be focused on when obtained from an asthma patient?
Attention should focus on previous intubations, ICU admissions, 2+ hospitalizations for asthma in the past year, and the presence of coexisting diseases.
How is asthma diagnosed?
Asthma is diagnosed based on clinical history, symptoms, and objective measurements of airway obstruction.
What criteria are used to diagnose asthma?
Asthma is diagnosed when a patient reports wheezing, chest tightness, or shortness of breath and demonstrates airflow obstruction on pulmonary function tests (PFTs) that is at least partially reversible with bronchodilators.
How is asthma severity classified?
Asthma severity is classified based on the symptoms, PFTs, and medication usage.
What are some direct measures of the severity of expiratory obstruction in asthma?
Forced expiratory volume in 1 second (FEV1), forced expiratory flow (FEF), and mid expiratory phase flow.
What is a typical FEV1 value in symptomatic asthmatic patients who come to the hospital?
FEV1 <35%.
What do flow-volume loops show in asthma?
Flow-volume loops show a downward scooping of the expiratory limb of the loop.
What change may occur in functional residual capacity (FRC) during moderate or severe asthma attacks?
FRC may increase substantially.
How can relief of obstruction after a bronchodilator aid in diagnosing asthma?
Relief of obstruction after a bronchodilator suggests the diagnosis of asthma in patients with expiratory obstruction.
Just a graph to look at
Just another graph to look at
What are the ABG findings typically associated with mild asthma?
Mild asthma is usually accompanied by a normal PaO2 and PaCO2.
What causes tachypnea and hyperventilation during an asthma attack?
Tachypnea and hyperventilation during an asthma attack are caused by neural reflexes of the lungs, not hypoxemia.
What are the most common ABG findings of symptomatic asthma?
Hypocarbia and respiratory alkalosis.
What may result in a PaO2 of <60 mmHg as the severity of expiratory obstruction increases?
Ventilation/perfusion mismatching
When is the PaCO2 likely to increase in asthma?
The PaCO2 is likely to increase when the forced expiratory volume in 1 second (FEV1) is <25% of predicted.
What are some CXR findings in patients with severe asthma?
Hyperinflation and hilar vascular congestion due to mucous plugging and pulmonary hypertension.
How can CXRs be helpful in asthma management?
CXRs can be helpful in determining the cause of an asthma exacerbation and ruling out other causes.
What cardiac findings may be present on an EKG during an asthma attack?
Signs of right ventricular strain or ventricular irritability.
What are some conditions included in the differential diagnosis of asthma?
Viral tracheobronchitis, sarcoidosis, rheumatoid arthritis with bronchitis, extrinsic or intrinsic airway compression, vocal cord dysfunction, tracheal stenosis, chronic bronchitis, COPD, and foreign body aspiration.
What is the primary aim of asthma treatment?
The primary aim of asthma treatment is to control symptoms and reduce exacerbations.
What is the first-line treatment for patients with mild asthma?
A short-acting inhaled β2 agonist.
When are daily inhaled corticosteroids recommended in asthma management?
Daily inhaled corticosteroids are recommended following short-acting β2 agonist treatment to improve symptoms, reduce exacerbations, and decrease the risk of hospitalization, especially in patients with <2 exacerbations/month.
What other therapies are available for asthma management besides inhaled corticosteroids and short-acting β2 agonists?
Inhaled muscarinic antagonists, leukotriene modifiers, and mast cell stabilizers.
When are systemic corticosteroids typically reserved for in asthma treatment?
Systemic corticosteroids are reserved for severe asthma that is uncontrolled with inhalational medications.
What is bronchial thermoplasty (BT)?
Bronchial thermoplasty (BT) is a recently approved nonpharmacologic treatment for refractory asthma.
How does bronchial thermoplasty work?
BT uses bronchoscopy to deliver radiofrequency ablation of airway smooth muscles to all lung fields except the right middle lobe.
How is bronchial thermoplasty typically performed?
The procedure is performed in three sessions and uses intense heat, which carries a risk of airway fire.
What is the purpose of bronchial thermoplasty in asthma treatment?
Loss of airway smooth muscle mass is thought to reduce bronchoconstriction.
How can serial pulmonary function tests (PFTs) be useful in asthma treatment?
Serial PFTs can be useful for monitoring the response to treatment.
What characterizes acute severe asthma?
Acute severe asthma: bronchospasm doesn’t resolve despite usual tx; considered life-threatening
What is the emergency treatment for acute severe asthma?
Emergency tx consists of high-dose, short-acting β2 agonists and systemic corticosteroids.
How frequently can inhaled β2 agonists be administered in acute severe asthma?
INH β2 agonists can be administered every 15-20 min for several doses w/o adverse hemodynamic effects.
What is the target oxygen saturation level in acute severe asthma, and how is it maintained?
Supplemental 02 is given to help maintain 02 saturation >90%.
Look at this cool chart
What percentage of asthmatics undergoing general anesthesia (GA) experience bronchospasm?
Bronchospasm has been reported in 0.2-4.2% of asthmatics undergoing GA.
What factors correlate with the risk of bronchospasm during GA?
The type of surgery (higher with upper abdominal and oncologic surgery) and how recent the last asthma attack occurred.
What are some mechanisms by which general anesthesia increases airway resistance?
Mechanisms include depression of the cough reflex, impairment of mucociliary function, reduction of palatopharyngeal muscle tone, depression of diaphragmatic function, and increased fluid in the airway wall.
Besides anesthesia, what are other factors that contribute to bronchospasm during surgery?
Other factors include airway stimulation by intubation, activation of the parasympathetic nervous system, and/or release of neurotransmitters such as substance P and neurokinins
What factors should be assessed during preoperative evaluation of patients with asthma?
Disease severity, effectiveness of current treatment, and the need for additional therapy before surgery.
What aspects of the patient’s history are important to note during preoperative assessment for asthma?
History of symptom control, frequency of exacerbations, need for hospitalization or intubation, previous anesthesia tolerance.
What physical signs should be noted during preoperative assessment for asthma?
Physical appearance and use of accessory muscles should be noted.
What diagnostic tests may be indicated for preoperative assessment of asthma?
Preoperative PFTs (especially FEV1) before and after bronchodilator may be indicated.
What interventions can often improve reversible components of asthma before surgery?
Preoperative chest physiotherapy, antibiotics, and bronchodilators.
When are arterial blood gases (ABGs) indicated during preoperative assessment for asthma?
ABGs are indicated if there is any question about the adequacy of ventilation or oxygenation
What medications should be continued until induction during preoperative management of asthma?
Anti-inflammatories and bronchodilators.
What is the recommended PEFR (peak expiratory flow rate) before surgery in patients with asthma?
Patients should be free of wheezing and have a PEFR of >80% of predicted or their personal best value before surgery.
What is COPD?
COPD is a disease of chronic airflow obstruction
What are the symptoms of COPD?
Symptoms include emphysema characterized by lung parenchymal destruction, chronic bronchitis, productive cough, and small airway disease.
What is lost in COPD due to bronchio-alveolar destruction?
Pulmonary elastic recoil is lost.
What is the worldwide prevalence of COPD, and what rank does it hold in terms of causes of death?
Worldwide, COPD has a prevalence of 10% and is the 3rd leading cause of death.
What are the consequences of COPD?
- Pathologic deterioration in elasticity or recoil within the lung parenchyma, which normally keeps the airways open.
- Pathologic changes that decrease bronchiolar wall structure, allowing them to collapse during exhalation.
- Increased velocity through the narrowed bronchioles, which lowers intrabronchial pressure and favors airway collapse.
- Active bronchospasm and obstruction resulting from increased pulmonary secretions.
- Destruction of lung parenchyma, enlarged air sacs, and development of emphysema.
What are some symptoms of COPD?
Symptoms of COPD vary with severity but usually include dyspnea at rest or exertion, chronic cough, and chronic sputum production.
What characterizes COPD exacerbations?
COPD exacerbations are characterized by acute worsening in airflow obstruction
What respiratory signs become evident as expiratory obstruction increases in COPD?
As expiratory obstruction increases, tachypnea and prolonged expiratory times become evident.