Obstructive Sleep Apnea Overview
122 Questions
0 Views

Obstructive Sleep Apnea Overview

Created by
@Harmony.Alexis_

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary risk factor for Obstructive Sleep Apnea (OSA)?

  • Age over 50 years
  • High blood pressure
  • Gender, male
  • Obesity (correct)

    • Which index is used for diagnosing the severity of sleep apnea?

  • Chronic Hypoxemia Index
  • STOP-Bang Score
  • Body Mass Index (BMI)
  • Apnea Plus Hypopnea (AHI) Index (correct)

    • What is a hallmark symptom of Obstructive Sleep Apnea?

  • Daytime somnolence (correct)
  • Persistent fatigue
  • Frequent headaches
  • Chronic cough

    • What type of medications are commonly used for treating OSA?

    <p>Antidepressants</p> Signup and view all the answers

    What preoperative consideration is essential for a patient with OSA?

    <p>Bring CPAP</p> Signup and view all the answers

    What is the expected sensitivity of the STOP-Bang questionnaire?

    <p>100%</p> Signup and view all the answers

    Which of the following treatments is considered surgical for OSA?

    <p>Uvulopalatopharyngoplasty</p> Signup and view all the answers

    Which physiological change is associated with OSA?

    <p>Decreased apneic oxygen reserve</p> Signup and view all the answers

    What is the hallmark feature of Chronic Obstructive Pulmonary Disease (COPD)?

    <p>Chronic productive cough</p> Signup and view all the answers

    Which type of emphysema predominantly affects the respiratory bronchioles in the upper lung lobes?

    <p>Centrilobular emphysema</p> Signup and view all the answers

    What is the most significant risk factor for developing COPD?

    <p>Cigarette smoking</p> Signup and view all the answers

    What is the classification for a patient with FEV₁ between 50% to 79%?

    <p>Moderate</p> Signup and view all the answers

    What physiological change occurs due to the inflammatory reaction in COPD?

    <p>Increased airway resistance</p> Signup and view all the answers

    Which of the following is NOT a common clinical manifestation of COPD?

    <p>Persistent fever</p> Signup and view all the answers

    What is a potential secondary cause of death in COPD patients?

    <p>Heart disease</p> Signup and view all the answers

    What is the primary method for managing intraoperative bronchospasm?

    <p>Increasing FiO₂ to 1.0</p> Signup and view all the answers

    What is the hallmark clinical feature of pulmonary edema?

    <p>Pink, frothy sputum</p> Signup and view all the answers

    Which of the following conditions could lead to non-cardiogenic pulmonary edema?

    <p>Acute respiratory distress syndrome (ARDS)</p> Signup and view all the answers

    Which treatment is commonly avoided when managing aspiration pneumonitis?

    <p>Antibiotics</p> Signup and view all the answers

    Which of the following is NOT a risk factor for developing ARDS?

    <p>Pulmonary fibrosis</p> Signup and view all the answers

    In which type of pneumothorax does air progressively accumulate to cause a mediastinal shift?

    <p>Tension pneumothorax</p> Signup and view all the answers

    What is the mechanism by which aspiration pneumonitis causes lung injury?

    <p>Caustic injury from gastric contents</p> Signup and view all the answers

    Which treatment modality is suggested for managing non-cardiogenic pulmonary edema?

    <p>Lung protective ventilation</p> Signup and view all the answers

    During the emergence phase of anesthesia, what measure is critical to verify?

    <p>Adequate reversal of neuromuscular blockade</p> Signup and view all the answers

    Which condition is primarily characterized by airway closure leading to atelectasis?

    <p>Aspiration pneumonitis</p> Signup and view all the answers

    What is the hallmark clinical feature of pulmonary hypertension?

    <p>Dyspnea/exercise intolerance</p> Signup and view all the answers

    What should be done for a patient presenting with sudden hypoxemia postoperatively?

    <p>Consider high-flow oxygen therapy</p> Signup and view all the answers

    What is a primary cause for the development of tension pneumothorax?

    <p>Chest trauma resulting in rib fractures</p> Signup and view all the answers

    What poor outcome is associated with a 5-year mortality rate in patients with pulmonary hypertension?

    <p>79%</p> Signup and view all the answers

    Which condition is a common cause of chronic cor pulmonale?

    <p>Chronic obstructive pulmonary disease (COPD)</p> Signup and view all the answers

    What is the typical pulmonary function change seen with atelectasis?

    <p>Decreased lung volumes</p> Signup and view all the answers

    Which intervention is NOT recommended in the management of aspiration pneumonitis?

    <p>Antibiotic therapy as routine</p> Signup and view all the answers

    Which of the following is a primary pathway leading to pulmonary embolism?

    <p>Deep vein thrombosis (DVT)</p> Signup and view all the answers

    What should be avoided during maintenance anesthesia in patients with pulmonary conditions to prevent hemodynamic instability?

    <p>Hypothermia</p> Signup and view all the answers

    Which medication is advised to minimize cardiac depression during anesthesia in pulmonary hypertension?

    <p>Etomidate</p> Signup and view all the answers

    What is a significant clinical manifestation of cor pulmonale?

    <p>Jugular venous distension</p> Signup and view all the answers

    Which non-invasive assessment tool is crucial for diagnosing pulmonary hypertension?

    <p>Doppler echocardiography</p> Signup and view all the answers

    What is a potential surgical option for treating severe cases of pulmonary hypertension?

    <p>Heart/lung transplant</p> Signup and view all the answers

    What is a characteristic pathophysiological feature of pulmonary embolism?

    <p>Occlusion of pulmonary blood flow</p> Signup and view all the answers

    Which condition is characterized by obesity coupled with daytime hypoventilation?

    <p>Obesity Hypoventilation Syndrome (OHS)</p> Signup and view all the answers

    Chronic hypoxemia and hypercarbia due to OSA can lead to an inflammatory state.

    <p>True</p> Signup and view all the answers

    What is the primary treatment for Obstructive Sleep Apnea (OSA)?

    <p>CPAP</p> Signup and view all the answers

    The _____ index quantifies the number of abnormal respiratory events per hour of sleep.

    <p>Apnea Plus Hypopnea (AHI)</p> Signup and view all the answers

    Which of the following is NOT a component of the STOP-Bang questionnaire?

    <p>Gender, female</p> Signup and view all the answers

    Match the treatment options with their types for Obstructive Sleep Apnea (OSA):

    <p>Lifestyle = Weight loss Medical = CPAP Surgical = Adenotonsillectomy Medications = Modafinil</p> Signup and view all the answers

    Patients with OSA are generally not sensitive to sedative effects.

    <p>False</p> Signup and view all the answers

    Describe a preoperative consideration for a patient with OSA.

    <p>Bring CPAP on the day of surgery.</p> Signup and view all the answers

    A crucial step during induction for a patient with OSA is to elevate the head and shoulders for _____ during ventilation.

    <p>ramping</p> Signup and view all the answers

    What percentage of obese patients are affected by OSA?

    <p>40%</p> Signup and view all the answers

    What is the hallmark clinical feature of pulmonary hypertension?

    <p>Dyspnea/exercise intolerance</p> Signup and view all the answers

    Cor pulmonale can only develop as a chronic condition.

    <p>False</p> Signup and view all the answers

    What is the incidence of pulmonary embolism in surgical patients?

    <p>Approximately 1%</p> Signup and view all the answers

    The primary cause of pulmonary embolism typically results from a __________.

    <p>deep vein thrombosis (DVT)</p> Signup and view all the answers

    Match the following conditions with their causes:

    <p>Pulmonary Hypertension = COPD Cor Pulmonale = Chronic left heart failure Pulmonary Embolism = DVT Acute Cor Pulmonale = Pulmonary Embolism</p> Signup and view all the answers

    What procedure can be performed to provide a definitive diagnosis for pulmonary embolism?

    <p>Cardiac catheterization</p> Signup and view all the answers

    Neuraxial anesthesia may cause significant hemodynamic alterations during anesthesia maintenance for patients with pulmonary conditions.

    <p>True</p> Signup and view all the answers

    Which medical treatments are commonly used for managing Pulmonary Arterial Hypertension (PAH)?

    <p>Prostanoids, endothelin receptor antagonists, phosphodiesterase inhibitors, diuretics</p> Signup and view all the answers

    The release of a __________ into circulation leads to occlusion of pulmonary circulation.

    <p>thrombus</p> Signup and view all the answers

    Which of the following statements about the prognosis of pulmonary hypertension is true?

    <p>The disease progresses rapidly.</p> Signup and view all the answers

    What is the hallmark clinical feature of pulmonary edema?

    <p>Pink, frothy sputum</p> Signup and view all the answers

    Hypoxemia is an expected feature of aspiration pneumonitis.

    <p>True</p> Signup and view all the answers

    In which condition do the alveoli collapse due to obstruction, leading to impaired gas exchange?

    <p>Atelectasis</p> Signup and view all the answers

    Increased pulmonary capillary pressure is a characteristic of __________ pulmonary edema.

    <p>cardiogenic</p> Signup and view all the answers

    Match the following conditions with their descriptions:

    <p>Pulmonary Edema = Accumulation of fluid in interstitium and alveoli Atelectasis = Airway collapse leading to impaired gas exchange Tension Pneumothorax = Progressive accumulation of air in pleural space causing mediastinal shift Aspiration Pneumonitis = Chemical injury to lung due to gastric contents</p> Signup and view all the answers

    What treatment should be considered for patients with acute respiratory distress syndrome (ARDS)?

    <p>Lung protective ventilation</p> Signup and view all the answers

    Hypotension is not a common sign of pneumothorax.

    <p>False</p> Signup and view all the answers

    What is the primary medical treatment for managing lidocaine-induced ventricular dysrhythmias?

    <p>Amiodarone</p> Signup and view all the answers

    The development of __________ is characterized by the rapid accumulation of fluid in the alveoli.

    <p>Acute Respiratory Distress Syndrome (ARDS)</p> Signup and view all the answers

    Which risk factor is majorly associated with the development of ARDS?

    <p>Sepsis</p> Signup and view all the answers

    What is the primary characteristic of emphysema?

    <p>Permanent enlargement of air spaces and destruction of alveolar walls</p> Signup and view all the answers

    Cigarette smoking is the most significant risk factor for Chronic Obstructive Pulmonary Disease (COPD).

    <p>True</p> Signup and view all the answers

    What is the hallmark clinical feature of chronic bronchitis?

    <p>chronic productive cough</p> Signup and view all the answers

    The decrease in elastic recoil of the lungs leads to _____ in patients with COPD.

    <p>airflow obstruction</p> Signup and view all the answers

    Match the following terms related to COPD with their definitions:

    <p>Chronic Bronchitis = Excess mucous secretion causing airflow obstruction Centrilobular Emphysema = Affects respiratory bronchioles in upper lung lobes Panlobular Emphysema = Widespread destruction of acini FEV₁ = Measurement used for classifying severity of lung obstruction</p> Signup and view all the answers

    Which of the following is NOT a common symptom associated with COPD?

    <p>Chest pain</p> Signup and view all the answers

    The progression of airflow limitation in COPD is generally reversible.

    <p>False</p> Signup and view all the answers

    What are two types of emphysema mentioned in the content?

    <p>centrilobular and panlobular</p> Signup and view all the answers

    COPD is a combination of both _____ and chronic bronchitis.

    <p>emphysema</p> Signup and view all the answers

    What is a likely secondary cause of death in individuals with COPD?

    <p>Heart disease</p> Signup and view all the answers

    What structure prevents aspiration during swallowing?

    <p>Larynx</p> Signup and view all the answers

    The nasal septum is formed entirely by cartilage.

    <p>False</p> Signup and view all the answers

    What are the three functions of the nose?

    <p>Heating, humidification, filtration</p> Signup and view all the answers

    The area of the respiratory zone which primarily functions in gas exchange is called the _____

    <p>alveoli</p> Signup and view all the answers

    Match the following components of the respiratory system with their descriptions:

    <p>Trachea = Structure preventing airway collapse Bronchi = Conduct air to each lung Larynx = Protective structure during swallowing Pharynx = Muscular tube extending to the esophagus</p> Signup and view all the answers

    Which of the following structures contains the true vocal cords?

    <p>Larynx</p> Signup and view all the answers

    The trachea is composed of complete rings of cartilage.

    <p>False</p> Signup and view all the answers

    What are the names of the four paranasal air sinuses?

    <p>Frontal, ethmoid, maxillary, sphenoid</p> Signup and view all the answers

    What does a V/Q ratio of 0 indicate?

    <p>Perfusion without ventilation</p> Signup and view all the answers

    A rightward shift in the oxyhemoglobin dissociation curve reduces the release of oxygen from hemoglobin.

    <p>False</p> Signup and view all the answers

    What is the primary factor that Dalton's Law of Partial Pressures emphasizes?

    <p>Total pressure equals the sum of partial pressures.</p> Signup and view all the answers

    The equation for the diffusion of gases across the alveolocapillary membrane is described by ______'s Law.

    <p>Fick</p> Signup and view all the answers

    Match the gas-related terms to their definitions:

    <p>Dead Space = Ventilation without perfusion Shunt = Perfusion without ventilation Alveolar Gas Equation = Calculation of PA<del>O2</del> Oxyhemoglobin Dissociation Curve = Relationship between pH and oxygen release</p> Signup and view all the answers

    What is the primary muscle of inspiration in the mechanics of breathing?

    <p>Diaphragm</p> Signup and view all the answers

    The pleura is the serous membrane that separates the lungs from the diaphragm.

    <p>False</p> Signup and view all the answers

    What is the relationship expressed by Boyle's Law?

    <p>Pressure and volume are inversely related.</p> Signup and view all the answers

    The __________ pressure is calculated as the difference between alveolar pressure and pleural pressure.

    <p>transpulmonary</p> Signup and view all the answers

    Match the following terms related to lung compliance:

    <p>Compliance = Measure of lung stiffness Elastic forces = Collagen and elastin in lung tissue Alveolar surface tension = Inhibits lung expansion High compliance = Easier expansion of the lung</p> Signup and view all the answers

    Which component of the thoracic cavity specifically surrounds the lungs?

    <p>Visceral pleura</p> Signup and view all the answers

    Bronchial circulation is responsible for the blood supply to the lungs and bronchi.

    <p>True</p> Signup and view all the answers

    What is the significance of the diaphragm in respiration?

    <p>It is the primary muscle that enables inhalation by expanding the thoracic cavity.</p> Signup and view all the answers

    The thoracic cavity consists of the left pleural cavity, right pleural cavity, and __________.

    <p>mediastinum</p> Signup and view all the answers

    Which of the following pressures refers specifically to the pressure within the alveoli?

    <p>Alveolar pressure</p> Signup and view all the answers

    Which system supplies deoxygenated blood for gas exchange in the lungs?

    <p>Pulmonary circulation</p> Signup and view all the answers

    The pulmonary circulation has a high-pressure system when compared to systemic circulation.

    <p>False</p> Signup and view all the answers

    What is the normal ventilation-perfusion ratio in the lungs?

    <p>0.8</p> Signup and view all the answers

    The ____ aorta supplies oxygenated blood to the conducting zone of the respiratory system.

    <p>thoracic</p> Signup and view all the answers

    Match the pulmonary pressures with their approximate values:

    <p>Right Ventricular Pressure = 15 mm Hg Pulmonary Artery Pressure = 20 mm Hg Pulmonary Capillary Pressure = 5 mm Hg Left Atrial Pressure = 7 mm Hg</p> Signup and view all the answers

    What effect does hypoxic pulmonary vasoconstriction have?

    <p>Shunts blood away from poorly ventilated regions</p> Signup and view all the answers

    Pulmonary vessels are narrower and less compliant than systemic arteries.

    <p>False</p> Signup and view all the answers

    What is the primary characteristic of the vessels in the pulmonary arterial system?

    <p>They are shorter, wider, and more distensible than systemic arteries.</p> Signup and view all the answers

    The left atrium receives oxygenated blood from the __________.

    <p>pulmonary veins</p> Signup and view all the answers

    Match the following pressures to their appropriate values:

    <p>Pulmonary wedge pressure = 5 mm Hg Pc = 7 mm Hg Pif = 8 mm Hg Πp = 28 mm Hg</p> Signup and view all the answers

    Which lung volume represents the amount of air inspired or expired with each normal breath?

    <p>Tidal Volume</p> Signup and view all the answers

    The vital capacity is the maximum amount of air that remains in the lungs after the most forceful expiration.

    <p>False</p> Signup and view all the answers

    What is the method used to indirectly measure certain lung volumes like Functional Residual Capacity?

    <p>Helium Dilution Method</p> Signup and view all the answers

    The maximum amount of air that the lungs can contain is known as _____ Lung Capacity.

    <p>Total</p> Signup and view all the answers

    Match the following lung volumes/capacities with their descriptions:

    <p>Tidal Volume = Amount of air for each normal breath Inspiratory Reserve Volume = Extra air that can be inspired with full force Residual Volume = Air remaining after forceful expiration Vital Capacity = Maximum air expelled after maximum inhalation</p> Signup and view all the answers

    What does the equation Minute Ventilation = Tidal Volume × Respiratory Rate calculate?

    <p>Volume of air moved in one minute</p> Signup and view all the answers

    Dead space refers to ventilated areas that receive adequate perfusion for gas exchange.

    <p>False</p> Signup and view all the answers

    What is the primary purpose of measuring Functional Residual Capacity?

    <p>To assess lung health and capacity for gas exchange</p> Signup and view all the answers

    The volume of air that remains in the lungs at the end of normal expiration is called _____ Capacity.

    <p>Functional Residual</p> Signup and view all the answers

    Which of the following can be an indirect measurement to determine lung volumes?

    <p>Helium Dilution Method</p> Signup and view all the answers

    Study Notes

    Obstructive Sleep Apnea (OSA)

    • A mechanical obstruction of the pharynx due to reduced muscle tone during sleep
    • Obesity is the biggest risk factor
    • 40% of obese patients have OSA
    • 80% of patients seeking bariatric surgery have OSA
    • The prevalence is increasing in children
    • OSA is linked to higher morbidity and mortality in hospitalized patients
    • OSA causes chronic hypoxemia and hypercarbia
    • Chronic hypoxemia and hypercarbia lead to an inflammatory response
    • OSA reduces functional residual capacity (FRC)
    • Decreased apneic oxygen reserve contributes to hypoxemia and hypercarbia

    Clinical Features and Diagnosis of OSA

    • Daytime sleepiness is a hallmark symptom
    • Habitual snoring and fragmented sleep are typical
    • Polysomnography is needed for a definitive diagnosis, and to establish severity
    • The Apnea-Hypopnea Index (AHI) quantifies the number of abnormal respiratory events per hour of sleep
    • STOP-Bang is a simple screening tool used preoperatively
    • STOP-Bang has a sensitivity of ~100% and a specificity of ~40%

    Treatment for OSA

    • Lifestyle modifications: weight loss
    • Medical treatment: CPAP, airway devices, medications (modafinil, methylxanthines, tricyclic antidepressants)
    • Surgical treatment: adenotonsillectomy, uvulopalatopharyngoplasty, hypoglossal nerve stimulator

    Anesthetic Management for OSA

    • Preoperative:
      • Bring CPAP to the hospital on the day of surgery
      • Conduct a thorough airway exam to anticipate difficulty with mask ventilation or laryngoscopy
      • Assess Mallampati score and neck circumference
      • Consider regional anesthesia or multimodal analgesia to minimize the need for sedatives
      • Minimize sedatives, as OSA patients are sensitive to their effects
    • Induction:
      • Anticipate difficult mask ventilation and laryngoscopy
      • Reduced FRC shortens apneic oxygen time
      • Elevate the head and shoulders (ramping)
      • Keep airway adjuncts (LMA/videolaryngoscope) available

    Chronic Obstructive Pulmonary Disease (COPD)

    • A preventable and treatable condition characterized by airflow obstruction that is not fully reversible
    • The airflow limitation usually progresses and is linked to an inflammatory response in the lungs caused by noxious particles or gases.

    Chronic Bronchitis

    • Obstructed expiratory airflow due to excessive mucous secretion
    • Occurs most days for at least three months per year for at least two consecutive years

    Emphysema

    • Permanent enlargement of air spaces distal to the terminal bronchioles, with destruction of alveolar walls
    • Centrilobular: impacts mainly the respiratory bronchioles in the upper lung lobes
    • Panlobular: widespread destruction of the air sacs

    Incidence, Outcomes, and Etiology of COPD

    • Cigarette smoking is the primary risk factor
    • Environmental pollutants and genetics also play a role
    • COPD is the third-leading cause of death, affecting approximately 5% of American adults
    • Death can result from respiratory failure or related comorbidities (e.g., heart disease, lung cancer)

    Pathophysiology of COPD

    • An inflammatory reaction in the lungs leads to progressive airflow obstruction (decreased FEV1)
    • Bronchial lumen size is reduced
    • Increased collapsibility of bronchial walls
    • Decreased elastic recoil of the lungs
    • A combination of emphysema and chronic bronchitis characterizes COPD

    Clinical Features and Diagnosis of COPD

    • A chronic productive cough and progressive exercise limitations are hallmarks
    • Clinical manifestations include dyspnea and wheezing
    • Pulmonary function testing (GOLD classification) establishes diagnosis and severity:
      • FEV1 ≥80% = mild
      • FEV1 50%-79% = moderate
      • FEV1 30%-49% = severe
      • FEV1 <30% = very severe

    Anesthetic Management for COPD

    • Preoperative:
      • Thorough history and physical exam to assess severity
      • Consider spirometry and arterial blood gas (ABG) analysis
      • Optimize medical management before surgery
    • Induction:
      • Consider rapid sequence induction (RSI)
      • Use propofol rather than etomidate or barbiturates
    • Maintenance:
      • Use sevoflurane as the least irritating volatile anesthetic
      • Avoid atracurium, mivacurium, morphine, B-antagonists, Hemabate, and NSAIDs
    • Emergence:
      • Consider deep extubation
      • Favour Sugammadex over anticholinesterase reversal agents to avoid bronchospasm
      • Confirm adequate reversal of neuromuscular blockade

    Intraoperative Bronchospasm

    • Administer additional anesthetic agents
    • Increase FiO2 to 100%
    • Administer a short-acting B2-agonist (albuterol)
    • Consider administering epinephrine 10 mcg/kg
    • Administer a corticosteroid (hydrocortisone 2-4 mg/kg)
    • Consider administering aminophylline

    Pulmonary Hypertension (PH)

    • Mean pulmonary artery pressure >25 mm Hg

    Incidence, Outcomes, and Etiology of PH

    • Rapid disease progression; 5-year mortality rate is 79%
    • Causes include COPD, connective tissue disorders, sarcoidosis, drug effects, and genetics/idiopathic

    Pathophysiology of PH

    • Increased vascular tone
    • Growth and proliferation of pulmonary vascular smooth muscle
    • Right ventricular overload that may lead to cor pulmonale

    Clinical Features and Diagnosis of PH

    • Dyspnea and exercise intolerance are hallmarks
    • Diagnosis is established through clinical evaluation and diagnostic tests

    Anesthetic Management for PH

    • Preoperative Considerations:
      • Consider ECG, echocardiogram, chest x-ray, and ABG
      • Continue medications for pulmonary hypertension
      • Consider regional anesthesia
    • Maintenance:
      • Neuraxial anesthesia may cause significant hemodynamic changes
      • Etomidate or high-dose opioids may be preferred to minimize cardiac depression
      • Consider arterial blood pressure monitoring
      • Consider a central venous catheter for major procedures

    Cor Pulmonale

    • Right heart failure secondary to pulmonary pathology

    Incidence, Outcomes, and Etiology of Cor Pulmonale

    • Cor pulmonale is the third most common cardiac disorder in individuals over 50 years old
    • Five times more prevalent in males
    • Cor pulmonale can be acute (e.g., pulmonary embolism) or chronic (e.g., COPD)

    Pathophysiology of Cor Pulmonale

    • Right ventricular dysfunction develops in response to pulmonary hypertension
    • The rate of right ventricular dysfunction progression depends on the severity and progression of pulmonary hypertension

    Clinical Features and Diagnosis of Cor Pulmonale

    • Cough, dyspnea, weakness, fatigue, hemoptysis, jugular venous distention, S3 gallop, S4 heart sound, murmurs, hepatomegaly, ascites, and dependent edema are common manifestations.
    • Doppler echocardiography: the velocity of tricuspid regurgitation correlates with invasive pulmonary artery pressure measurements
    • Cardiac catheterization: provides information about pressures in the pulmonary system and heart

    ###Treatment for Cor Pulmonale

    • Medical: Oxygen therapy, medications (prostanoids, endothelin receptor antagonists, phosphodiesterase inhibitors, diuretics)
    • Surgical: Heart/lung transplant

    Anesthetic Management for Cor Pulmonale

    • Preoperative:
      • Consider regional anesthesia
    • Maintenance:
      • Maintain adequate oxygenation
      • Avoid acidosis
      • Minimize stimuli that increase sympathetic tone
      • Avoid hypothermia

    Pulmonary Embolism (PE)

    • Occlusion of pulmonary blood flow by embolic material, causing obstruction and ventilation/perfusion mismatch

    Incidence, Outcomes, and Etiology of PE

    • Occurs in approximately 1% of surgical patients
    • Occurs in up to 30% of orthopedic surgical patients
    • Usually caused by a deep vein thrombosis (DVT) originating from the iliofemoral vessels
    • Other causes include DVT, air, CO2, tumor, bone, fat, and catheter fragments
    • Virchow's Triad: venous stasis, venous injury, and hypercoagulable state

    Pathophysiology of PE

    • Thrombus formation
    • Release of thrombus into the circulation
    • Pulmonary circulation occlusion
    • Increased pulmonary vascular resistance proximal to the occlusion, decreased perfusion distal to the occlusion
    • Ventilation/perfusion mismatch
    • Alveolar damage

    Clinical Features and Diagnosis of PE

    • Hallmark: Sudden-onset dyspnea, a sudden decrease in EtCO2
    • Clinical manifestations: Hypotension, tachycardia, hypoxemia, wheezing, and tachypnea

    Treatment for PE

    • Medical: Thrombolytic agents, anticoagulation
    • Surgical: Embolectomy (thromboendartectomy, rheolytic embolectomy, rotational embolectomy, suction embolectomy); inferior vena cava (IVC) filter insertion

    Anesthetic Management for PE

    • Induction:
      • Use etomidate
      • Avoid ketamine and nitrous oxide (N2:O)
    • Maintenance:
      • Consider high FiO2
      • Consider monitoring central venous pressure (CVP) and pulmonary artery pressure (PAP)

    Intraoperative Pulmonary Embolism

    • Increase FiO2 to 100%
    • Discontinue anesthetic agents
    • Administer sympathomimetics and fluids/blood as needed
    • Administer lidocaine or amiodarone for ventricular dysrhythmias
    • Prepare for thrombolysis or pulmonary embolectomy
    • Consider cardiopulmonary bypass as a temporizing measure

    Restrictive Pulmonary Disease (Pulmonary Edema)

    • Conditions that interfere with normal lung expansion during inspiration

    Incidence, Outcomes, and Etiology of Restrictive Pulmonary Disease

    • Pulmonary edema refers to an accumulation of excess fluid in the interstitium and alveoli
    • Negative-pressure pulmonary edema may result from acute airway obstruction

    Pathophysiology of Restrictive Pulmonary Disease

    • Imbalance of Starling's forces leading to pulmonary edema
    • Cardiogenic: high pulmonary capillary pressure
    • Non-cardiogenic: Increased permeability of the alveolar-capillary membrane (e.g., sepsis, ARDS)

    Clinical Features and Diagnosis of Restrictive Pulmonary Disease

    • Hallmark: pink, frothy sputum
    • Clinical manifestations: Tachypnea, accessory muscle use, tachycardia, hypertension, diaphoresis, and basilar crackles on auscultation
    • Chest X-ray findings:
      • Enlarged cardiac silhouette
      • 'White-out' appearance

    Treatment Restrictive Pulmonary Disease

    • Medical: Oxygen therapy, CPAP or mechanical ventilation, fluid restriction, medications (morphine, nitroprusside, inotropes)

    Aspiration Pneumonitis

    • Movement of gastric contents into the lungs, causing chemical injury to lung tissue.

    Incidence, Outcomes, and Etiology of Aspiration Pneumonitis

    • Overall incidence ~1/3000 anesthetics
    • ~1/1500 emergency anesthetics or Cesarean deliveries
    • Occurs when protective airway reflexes are inhibited, usually after vomiting or gastroesophageal reflux
    • Risk factors: Emergency surgery with a full stomach, bowel obstruction, pregnancy, and acute trauma
    • Often resolves without treatment

    ###Pathophysiology of Aspiration Pneumonitis

    • Immediate damage to lung parenchyma by caustic aspirate
    • Atelectasis develops within minutes, leading to airway closure and decreased compliance
    • Alveolar macrophages release inflammatory cytokines (IL-8, TNF-alpha), attracting neutrophils that release oxygen radicals and proteases
    • Secondary injury results from fibrin deposition and alveolar necrosis
    • Damage to the alveolar-capillary membrane
    • Impaired gas exchange
    • Capillary leak
    • Hemodynamic changes
    • Myocardial ischemia and acidosis due to hypoxemia

    ###Clinical Features and Diagnosis of Aspiration Pneumonitis

    • Hallmark: Arterial hypoxemia
    • Clinical manifestations: Tachypnea, dyspnea, cyanosis, tachycardia, and hypertension
    • Diagnosis: ABG and chest radiography
    • Chest radiography: Demonstrates aspirate in the perihilar and dependent lung regions
    • Differential diagnosis: High concern in an otherwise healthy patient who develops unexplained/sudden hypoxemia intra- or postoperatively

    Treatment for Aspiration Pneumonitis

    • Medical: Ventilation (consider low FiO2, PEEP), consider steroids, consider lidocaine 1.5 mg/kg, avoid routine administration of antibiotics, avoid routine use of deep tracheal suctioning/bronchoscopy

    Anesthetic Management for Aspiration Pneumonitis

    • Preoperative Considerations:
      • NPO
      • Identify risk factors
      • Pharmacologic prophylaxis
        • Nonparticulate antacids (sodium citrate with citric acid)
        • H2 receptor antagonists (famotidine)
        • PPIs (pantoprazole)
        • Antiemetics (ondansetron)
    • Induction:
      • Consider RSI with cricoid pressure
      • Consider videolaryngoscopy
      • If vomiting, reflux, or aspiration occur during induction:
        • Tilt the patient's head downwards or turn them to the left side
        • Suction the oropharynx/ET tube
        • Consider applying PEEP
        • Consider postponing surgery
    • Maintenance:
      • Avoid excessive administration of sedating medication
      • Evacuate the stomach
    • Emergence:
      • Awake extubation
      • Confirm adequate reversal of neuromuscular blockade

    Acute Respiratory Distress Syndrome (ARDS)

    • A condition occurring in critically ill patients where fluid accumulates in the alveoli, causing ventilation/perfusion mismatch

    Incidence, Outcomes, and Etiology of ARDS

    • Risk of developing ARDS is additive:
      • 1 risk factor - 25%
      • 2 risk factors - 42%
      • 3 risk factors - 85%
    • Major risk factors: Sepsis, bacterial pneumonia, trauma, aspiration pneumonitis
    • ARDS has a mortality rate of ~50%

    Pathophysiology of ARDS

    • Damage to the alveolar-capillary membrane triggers a diffuse inflammatory response
    • Capillary endothelium: Releases cytokines and membrane-bound phospholipids, activates leukocytes and macrophages, produces microemboli
    • Pulmonary vasoconstriction, bronchoconstriction, altered vascular reactivity/permeability
    • Increased pulmonary vascular resistance with the potential development of cor pulmonale

    Clinical Features and Diagnosis of ARDS

    • Hallmark: Non-cardiogenic pulmonary edema
    • Clinical manifestations: Dyspnea, hypoxemia, diffuse bilateral pulmonary infiltrates, decreased pulmonary compliance
    • ARDS is precipitated by a noxious event (e.g., trauma, bacterial pneumonia)

    Treatment for ARDS

    • Medical: Lung-protective ventilation (supplemental O2), afterload reduction/inotropic support, prone positioning, inhaled nitric oxide (iNO)

    Anesthetic Management for ARDS

    • Maintenance:
      • Ventilation:
        • Consider tidal volume (Vt) 6-8 mL/kg ideal body weight (IBW)
        • Consider PEEP
        • Avoid peak inspiratory pressures (PIPs) >30 cm H20
      • Avoid excessive administration of IV fluids
      • Consider monitoring arterial blood pressure, central venous pressure, cardiac output, and urinary output

    Pneumothorax

    • Simple Pneumothorax: Air accumulation in the pleural space; no communication between the pleural space and the atmosphere
    • Communicating Pneumothorax: Air accumulation in the pleural space due to communication between the pleural space and the atmosphere
    • Tension Pneumothorax: Progressive air accumulation in the pleural space that results in mediastinal shift
    • Hemothorax: Blood accumulation in the pleural space

    Incidence, Outcomes, and Etiology of Pneumothorax

    • Spontaneous (sneezing, coughing)
    • Chest trauma (rib fracture)
    • Barotrauma
    • Subclavian central line insertion
    • Supraclavicular/infraclavicular brachial plexus block
    • Surgical procedures (mediastinoscopy, radical neck dissection, mastectomy, axillary lymph node dissection, nephrectomy)

    ###Clinical Features and Diagnosis of Pneumothorax

    • Hallmark: Decreased SpO2, increased peak inspiratory pressures, tachypnea, hypotension, tachycardia
    • Clinical manifestations: Asymmetric chest wall movement, tracheal shift, hyperresonance
    • Differential diagnosis: High concern in a patient with a history of chest trauma who develops an acute decrease in pulmonary compliance

    Treatment for Pneumothorax

    • Simple Pneumothorax:
      • Catheter aspiration
      • Tube thoracostomy
    • Communicating Pneumothorax:
      • Semi-occlusive dressing
      • Supplemental O2
      • Tube thoracostomy
    • Tension Pneumothorax:
      • Needle thoracostomy
      • Tube thoracostomy
    • Hemothorax:
      • Tube thoracostomy
      • Consider blood transfusion

    Atelectasis

    • A pathological condition characterized by abnormal alveolar gas exchange due to airway collapse.

    Incidence, Outcomes, and Etiology of Atelectasis

    • Occurs in ~90% of patients who receive general anesthesia
    • Develops within minutes and may persist for hours or days
    • Most common after thoracic/upper abdominal surgery
    • The most common cause of postoperative respiratory dysfunction

    Pathophysiology of Atelectasis

    • Blockage or obstruction of airways can result from:
      • Compression of lung tissue
      • Impaired surfactant
      • Absorption of oxygen from nitrogen-free alveoli

    Obstructive Sleep Apnea

    • Mechanical obstruction of the pharynx during sleep due to decreased muscle tone.
    • Obesity is the most significant risk factor, affecting 40% of obese patients and 80% of patients undergoing bariatric surgery.
    • Increasing prevalence in children.
    • Associated with increased morbidity and mortality in hospitalized patients.
    • Results in chronic hypoxemia and hypercarbia, leading to an inflammatory state.
    • Decreases functional residual capacity (FRC) and apneic oxygen reserve.
    • Clinical Features: Daytime somnolence, habitual snoring, and fragmented sleep.
    • Diagnosis: Polysomnography provides objective diagnosis and severity gradation.
    • STOP-Bang Score: Used for preoperative evaluation, requires at least three of the following:
      • Snoring
      • BMI > 35 kg/m²
      • Tiredness
      • Age > 50 years
      • Observed apnea
      • Neck circumference > 40 cm
      • High blood pressure
      • Gender (male)
    • Treatment:
      • Lifestyle: Weight loss.
      • Medical: CPAP, airway devices, medications (modafinil, methylxanthines, tricyclic antidepressants).
      • Surgical: Adenotonsillectomy, uvulopalatopharyngoplasty, hypoglossal nerve stimulator.

    Anesthetic Management of Obstructive Sleep Apnea

    • Preoperative Considerations:
      • Ensure CPAP is available on the day of surgery.
      • Perform thorough airway examination to anticipate difficult mask ventilation and laryngoscopy.
      • Assess Mallampati score and neck circumference.
      • Consider regional anesthesia or multimodal analgesia to minimize sedation.
      • Minimize or avoid sedatives due to increased sensitivity in patients with OSA.
    • Induction:
      • Anticipate difficult mask ventilation and laryngoscopy.
      • Decreased FRC leads to decreased apneic oxygen time.
      • Elevate head and shoulders (ramping).
      • Have airway adjuncts (LMA/videolaryngoscope) readily available.
    • Postoperative Considerations:
      • Monitor ventilation and oxygenation.
      • Consider CPAP in the PACU.
      • Prolonged monitoring (6-24 hours) may be necessary.

    Chronic Obstructive Pulmonary Disease (COPD)

    • Preventable and treatable disease characterized by airflow limitation that is not fully reversible.
    • Airflow limitation progresses and is associated with an inflammatory response in the lungs.
    • Etiology: Cigarette smoking is the most significant risk factor. Other risk factors include environmental pollutants and genetics.
    • Pathophysiology: Inflammatory reaction in the lungs leading to progressive airflow obstruction, decreased FEV1, decreased bronchial lumen size, increased bronchial wall collapsibility, and decreased lung elastic recoil.
    • Clinical Features: Chronic productive cough, progressive exercise limitations, dyspnea, wheezing.
    • Diagnosis: Pulmonary function testing (GOLD Classification):
      • Mild: FEV1 ≥ 80%
      • Moderate: FEV1 50%-79%
      • Severe: FEV1 30%-49%
      • Very Severe: FEV1 < 30%
    • Treatment: Bronchodilators, inhaled corticosteroids, pulmonary rehabilitation, oxygen therapy, smoking cessation.

    Anesthetic Management of COPD

    • Preoperative Considerations:
      • Optimize pulmonary function before surgery.
      • Cessation of smoking.
    • Induction:
      • Rapid sequence induction may be required for difficult airways.
      • Consider using etomidate or propofol for induction, as they are less likely to cause bronchospasm.
      • Avoid succinylcholine due to the risk of hyperkalemia.
    • Maintenance:
      • Consider using sevoflurane, the least irritating volatile anesthetic.
      • Avoid atracurium, mivacurium, morphine, beta-blockers, Hemabate, and NSAIDs due to their potential to induce bronchospasm.
    • Emergence:
      • Deep extubation may be necessary.
      • Consider using sugammadex for neuromuscular blockade reversal to minimize the risk of bronchospasm.
      • Verify adequate reversal of neuromuscular blockade.

    Intraoperative Bronchospasm Management

    • Treatment:
      • Administer additional anesthetic agents.
      • Increase FiO2 to 1.0 (100%).
      • Administer short-acting beta-2 agonist (albuterol).
      • Consider administering epinephrine 10 mcg/kg.
      • Administer a corticosteroid (hydrocortisone 2-4 mg/kg).
      • Consider administering aminophylline.

    Pulmonary Hypertension

    • Defined as a mean pulmonary artery pressure (PAP) greater than 25 mmHg.
    • Etiology: COPD, connective tissue disorders, sarcoidosis, drug effects, genetics, idiopathic.
    • Pathophysiology: Increased vascular tone, pulmonary vascular smooth muscle growth and proliferation, right ventricular overload leading to cor pulmonale.
    • Clinical Features: Dyspnea, exercise intolerance.
    • Treatment: Oxygen therapy, medications (prostanoids, endothelin receptor antagonists, phosphodiesterase inhibitors), heart/lung transplantation.

    Anesthetic Management of Pulmonary Hypertension

    • Preoperative Considerations:
      • Consider ECG, echocardiogram, chest x-ray, and ABG.
      • Continue medications for pulmonary hypertension.
      • Consider regional anesthesia.
    • Maintenance:
      • Neuraxial anesthesia may cause significant hemodynamic alterations.
      • Etomidate or high-dose opioids may be preferable to minimize cardiac depression.
      • Consider arterial blood pressure monitoring.
      • Consider a central venous catheter for major procedures.

    Cor Pulmonale

    • Right heart failure secondary to pulmonary pathology.
    • Etiology: Acute (e.g., PE) or chronic (e.g., COPD).
    • Pathophysiology: Right ventricular dysfunction develops in response to pulmonary hypertension.
    • Clinical Features: Cough, dyspnea, weakness, fatigue, hemoptysis, jugular venous distension, S3 gallop, S4 heart sound, murmur, hepatomegaly, ascites, dependent edema.
    • Diagnosis: Doppler echocardiography (tricuspid regurgitation velocity), cardiac catheterization.
    • Treatment: Oxygen therapy, medications (prostanoids, endothelin receptor antagonists, phosphodiesterase inhibitors, diuretics), heart/lung transplantation.

    Anesthetic Management of Cor Pulmonale

    • Preoperative Considerations:
      • Consider regional anesthesia.
    • Maintenance:
      • Maintain adequate oxygenation.
      • Avoid acidosis.
      • Avoid stimuli that increase sympathetic tone.
      • Avoid hypothermia

    Pulmonary Embolism (PE)

    • Occlusion of pulmonary blood flow by embolic material, resulting in obstruction of pulmonary blood flow.
    • Etiology: Usually caused by deep vein thrombosis (DVT) from the iliofemoral vessels. Other emboli include air, CO2, tumor, bone, fat, and catheter fragments.
    • Virchow's Triad:
      • Venous stasis.
      • Venous injury.
      • Hypercoagulable state
    • Pathophysiology: Thrombus formation, release of thrombus into circulation, occlusion of pulmonary circulation, increased pulmonary vascular resistance (PVR) proximal to occlusion, decreased perfusion distal to occlusion, V/Q mismatch, alveolar damage.
    • Clinical Features: Sudden-onset dyspnea, sudden decrease in EtCO2, hypotension, tachycardia, hypoxemia, wheezing, tachypnea.
    • Treatment: Thrombolytic agents, anticoagulation, embolectomy, IVC filter insertion.

    Anesthetic Management of Pulmonary Embolism

    • Induction:
      • Etomidate is preferred for induction.
      • Avoid ketamine and N2O.
    • Maintenance:
      • Consider high FiO2.
      • Consider monitoring central venous pressure (CVP) and PAP.

    Intraoperative Pulmonary Embolism Management

    • Treatment:
      • Increase FiO2 to 1.0 (100%).
      • Discontinue administration of anesthetic agents.
      • Administer sympathomimetics and fluid/blood as needed.
      • Administer lidocaine or amiodarone in the presence of ventricular dysrhythmias.
      • Prepare for thrombolysis or pulmonary embolectomy.
      • Consider cardiopulmonary bypass as a temporizing measure.

    Restrictive Pulmonary Disease (Pulmonary Edema)

    • Conditions that interfere with normal lung expansion during inspiration.
    • Etiology:
      • Acute intrinsic (e.g., pulmonary edema, aspiration pneumonitis, ARDS)
      • Chronic intrinsic (e.g., idiopathic pulmonary fibrosis, sarcoidosis, radiation injury)
      • Chronic extrinsic (e.g., flail chest, pneumothorax, pleural effusion)
    • Pathophysiology: Imbalance of Starling's forces leading to pulmonary edema:
      • Cardiogenic: High pulmonary capillary pressure.
      • Non-cardiogenic: Increased permeability of the alveolar-capillary membrane.
    • Clinical Features:
      • Hallmark: Pink, frothy sputum.
      • Tachypnea, accessory muscle use, tachycardia, hypertension, diaphoresis, basilar crackles on auscultation.
    • Diagnosis: Chest x-ray (enlarged cardiac silhouette, "white-out" appearance).
    • Treatment: Oxygen therapy, CPAP or mechanical ventilation, fluid restriction, medications (morphine, nitroprusside, inotropes).

    Aspiration Pneumonitis

    • Movement of gastric contents from the stomach to the lungs, resulting in chemical injury to the lung tissue.
    • Incidence: Approximately 1/3000 anesthetics, 1/1500 emergency anesthetics or cesarean deliveries.
    • Etiology: Occurs when protective airway reflexes are inhibited, usually after vomiting or gastroesophageal reflux.
    • Risk Factors: Emergency surgery with a full stomach, bowel obstruction, pregnancy, acute trauma.
    • Pathophysiology: Immediate damage to lung parenchyma by the caustic aspirate, atelectasis, release of inflammatory cytokines by alveolar macrophages, secondary injury, impaired gas exchange, capillary leak, hemodynamic changes, myocardial ischemia, and acidosis.
    • Clinical Features:
      • Hallmark: Arterial hypoxemia.
      • Tachypnea, dyspnea, cyanosis, tachycardia, hypertension.
    • Diagnosis: ABG and chest radiography (demonstrates aspirate in the perihilar and dependent lung regions).

    Aspiration Pneumonitis Treatment

    • Ventilation (low FiO2, PEEP), steroids, lidocaine 1.5 mg/kg, avoid routine administration of antibiotics, avoid routine deep tracheal suctioning/bronchoscopy.

    Anesthetic Management of Aspiration Pneumonitis

    • Preoperative Considerations:
      • NPO status.
      • Recognize risk factors.
      • Pharmacologic prophylaxis:
        • Nonparticulate antacid (sodium citrate with citric acid).
        • H2 receptor antagonist (famotidine).
        • PPI (pantoprazole).
        • Antiemetics (ondansetron).
    • Induction:
      • Consider Rapid Sequence Induction with cricoid pressure.
      • Consider videolaryngoscopy.
      • If vomiting, reflux, or aspiration occur:
        • Tilt the patient's head downward or turn the patient to the left side.
        • Suction the oropharynx/ETT.
        • Consider applying PEEP.
        • Consider postponing surgery.
    • Maintenance: Avoid excessive administration of sedating medication.
      • Evacuate the stomach.
    • Emergence:
      • Awake extubation.
      • Verify adequate reversal of neuromuscular blockade.

    Acute Respiratory Distress Syndrome (ARDS)

    • Condition occurring in critically ill patients in which fluid accumulates in the alveoli, resulting in a mismatch of ventilation and perfusion.
    • Incidence: Risk is additive with multiple risk factors:
      • 1 risk factor: 25% risk.
      • 2 risk factors: 42% risk.
      • 3 risk factors: 85% risk.
    • Risk Factors:
      • Major: Sepsis, bacterial pneumonia, trauma, aspiration pneumonitis.
    • Mortality Rate: Approximately 50%.
    • Pathophysiology: Damage to the alveolar-capillary membrane leading to a diffuse inflammatory response:
      • Capillary endothelium releases cytokines and membrane-bound phospholipids.
      • Complement system activates leukocytes and macrophages, producing microemboli.
    • Clinical Features:
      • Hallmark: Noncardiogenic pulmonary edema.
      • Dyspnea, hypoxemia, diffuse bilateral pulmonary infiltrates, decreased pulmonary compliance.

    Treatment of ARDS

    • Lung protective ventilation (supplemental O2), afterload reduction/inotropic support, prone positioning, inhaled nitric oxide (iNO).

    Anesthetic Management of ARDS

    • Maintenance:
      • Ventilation:
        • Consider VT 6-8 mL/kg IBW.
        • Consider PEEP.
        • Avoid PIPs > 30 cm H2O.
      • Avoid excessive administration of IV fluids.
      • Consider monitoring arterial blood pressure, central venous pressure, cardiac output, urinary output.

    Pneumothorax

    • Simple pneumothorax: Accumulation of air in the pleural space with no communication between the space and the atmosphere.
    • Communicating pneumothorax: Accumulation of air in the pleural space due to communication between space and the atmosphere.
    • Tension pneumothorax: Progressive accumulation of air in the pleural space, resulting in mediastinal shift.
    • Hemothorax: Accumulation of blood in the pleural space.
    • Etiology: Spontaneous (sneezing, coughing), chest trauma (rib fracture), barotrauma, subclavian central line insertion, supraclavicular/infraclavicular brachial plexus block, surgical procedures.

    Clinical Features of Pneumothorax

    • Hallmark: Decreased SpO2, increased peak inspiratory pressures, tachypnea, hypotension, tachycardia.
    • Clinical Manifestations: Asymmetric chest wall movement, tracheal shift, hyperresonance.
    • Treatment:
      • Simple pneumothorax: Catheter aspiration, tube thoracostomy.
      • Communicating pneumothorax: Semi-occlusive dressing, supplemental O2, tube thoracostomy.
      • Tension pneumothorax: Needle thoracostomy, tube thoracostomy.
      • Hemothorax: Tube thoracostomy, consider blood transfusion.

    Atelectasis

    • Pathologic condition characterized by abnormal alveolar gas exchange due to airway collapse.
    • Incidence: Occurs in approximately 90% of patients who receive general anesthesia.
    • Etiology: Compression of lung tissue, impaired surfactant, absorption of oxygen from nitrogen-free alveoli.
    • Pathophysiology: Blockage or obstruction of the airways, decreased compliance.
    • Treatment: Deep breathing exercises, incentive spirometry, early mobilization, supplemental oxygen.

    Respiratory System Anatomy

    • Upper Airway: Includes the nose, mouth, pharynx, and larynx.
    • Nose:
      • Structures: Ala nasi (alar cartilage), anterior nares, nasal vestibules, nasal fossae, nasal septum (vomer bones and cartilages), nasal conchae, nasopharynx, nasal choanae, paranasal sinuses (frontal, ethmoid, maxillary, sphenoid).
      • Functions: Heating, humidification, filtration, olfaction.
    • Pharynx: Muscular tube extending from the skull base to the esophagus at vertebral level C6. Contains tonsils, aggregations of lymphoid tissue.
    • Larynx:
      • Protective structure that prevents aspiration during swallowing, extending from vertebral level C3 to C6. Composed of one bone and nine cartilages, ligaments, muscles, and membranes.
      • Structures: Vestibular folds (fibrous tissue covered by mucous membranes), true vocal cords (fibromembranous folds),
      • Musculature: Various muscles control vocal cord movement and airway protection.
      • Cormack-Lehane Classification: Describes the visibility of the laryngeal structures during laryngoscopy.
    • Trachea: Protective structure that prevents airway collapse, extending from the inferior larynx to the carina. Composed of incomplete rings of cartilage.
    • Bronchi:
      • Neurovascular Structures: Supplied by arteries (bronchial), drained by veins (bronchial), and innervated by both sympathetic and parasympathetic nerves.
      • Bronchodilation: Sympathetic stimulation.
      • Bronchoconstriction: Parasympathetic stimulation, histamine, and slow reactive substance of anaphylaxis.
    • Respiratory Zone: Includes respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli.
    • Alveoli: Area of respiratory zone primarily responsible for gas exchange.
    • Pulmonary Hilum: Conduit to the lung, containing the mainstem bronchus, pulmonary circulation, bronchial circulation, lymphatics/lymph nodes, and pulmonary innervation.
    • Thoracic Cavity: Contains the left pleural cavity, mediastinum, and right pleural cavity.
      • Pleura: Serous membrane separating the lungs from the mediastinum and thoracic cage (parietal: lines the chest wall, mediastinum, diaphragm; visceral: lines the lungs).

    Mechanics of Breathing

    • Diaphragm: Primary muscle of inspiration, a bilateral dome that functions independently. Separates the thoracic and abdominal cavities.
    • Boyle's Law: Relates pressure and volume of a gas (P1V1 = P2V2).
      • Inspiration: Increased lung volume, decreased lung pressure.
      • Expiration: Decreased lung volume, increased lung pressure.
    • Pleural, Alveolar, and Transpulmonary Pressures:
      • Pleural Pressure (Ppl): Pressure within the pleural space.
      • Alveolar Pressure (Palv): Pressure within the alveoli.
      • Transpulmonary Pressure: Difference between alveolar and pleural pressure (Palv - Ppl).
    • Lung Compliance: Measure of lung stiffness, indicating the amount of force required to expand the lung. Influenced by elastic forces of lung tissue and surface tension.
    • Lung Volumes:
      • Tidal Volume: Amount of air inspired or expired with each normal breath.
      • Inspiratory Reserve Volume: Extra air inspired with forceful inspiration.
      • Expiratory Reserve Volume: Extra air expired with forceful expiration.
      • Residual Volume: Air remaining in lungs after forced expiration.
    • Lung Capacities:
      • Inspiratory Capacity: Maximum air inspired from normal expiratory level.
      • Functional Residual Capacity: Air remaining in lungs at the end of normal expiration.
      • Vital Capacity: Maximum air expelled after maximal inspiration and expiration.
      • Total Lung Capacity: Maximum air the lungs can hold.
    • Helium Dilution Method: Indirect measurement used to determine lung volumes/capacities that cannot be measured directly (FRC, RV, TLC).

    Ventilation & Gas Exchange

    • Minute Ventilation: Volume of air moved per minute (Tidal Volume x Respiratory Rate).
    • Dead Space: Ventilated areas that do not participate in gas exchange.
    • Alveolar Ventilation: Volume of air available for gas exchange per minute (Respiratory Rate x (Tidal Volume - Dead Space)).
    • Dalton's Law of Partial Pressures: The total pressure of a gas mixture is the sum of the partial pressures of its components.
    • Alveolar Gas Equation: Calculates the partial pressure of oxygen in the alveoli (PAO2).
    • Fick's Law: Describes the diffusion of gases across the alveolocapillary membrane; rate of diffusion is directly proportional to surface area, diffusion coefficient, and pressure difference, and inversely proportional to membrane thickness.

    Oxygen Transport in the Blood

    • Oxygen Transport
      • Physical Dissolution in Plasma: Minimal amount.
      • Bound to Hemoglobin: Majority of oxygen transport.
    • Oxyhemoglobin Dissociation Curve:
      • Rightward Shift: Enhances oxygen release from hemoglobin (increased H+, CO2, temperature, 2,3-BPG).
      • Leftward Shift: Reduces oxygen release from hemoglobin (decreased H+, CO2, temperature, 2,3-BPG).

    Pulmonary Circulation

    • Bronchial Circulation: High pressure, low flow circulation. Supplies oxygenated blood to the conducting zone of the respiratory system.
    • Pulmonary Circulation: Low pressure, high flow circulation. Supplies deoxygenated blood to the respiratory zone for gas exchange.

    Pulmonary System Pressures

    • Right Ventricular Pressure: Pressure in the right ventricle.
    • Pulmonary Artery Pressure (PAP): Pressure within the pulmonary arteries.
    • Pulmonary Capillary Pressure: Pressure within the pulmonary capillaries.
    • Pulmonary Wedge Pressure: Estimate of left atrial pressure.
    • Left Atrial/Pulmonary Venous Pressures: Pressure in the left atrium and pulmonary veins.

    Ventilation-Perfusion Matching

    • Ventilation-Perfusion Ratio (V/Q): Ratio of ventilation to perfusion, normally 0.8. Varies in different lung regions.
      • V/Q = ∞: Dead space (ventilated but not perfused).
      • V/Q = 0: Shunt (perfused but not ventilated).

    Hypoxic Pulmonary Vasoconstriction

    • Systemic Circulation: Vessels constrict in response to decreased oxygen.
    • Pulmonary Circulation: Unique adaptation to shunt blood away from poorly ventilated areas, redirecting it to better ventilated areas.

    Other Important Concepts

    • Surface Tension: Causes collapse of small airways (laplace's law). Surfactant reduces surface tension, preventing alveolar collapse.
    • Starling Forces: Govern fluid movement across the capillary membrane. (Pc, Πif, Pif, Πp)

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Pulm Pathophysiology Powerpoint to Word Doc PDF
    Pulmonary Physiology Slides PDF

    Description

    This quiz provides an overview of Obstructive Sleep Apnea (OSA), including its causes, risk factors like obesity, and clinical features. It explores the impact of OSA on health, the importance of diagnosis using tools like polysomnography, and the implications for treatment. Test your knowledge about this increasingly prevalent condition.

    More Like This

    Sleep Disorder Expert
    41 questions

    Sleep Disorder Expert

    HallowedHeliotrope avatar
    HallowedHeliotrope
    Obstructive Sleep Apnea Symptoms Quiz 3
    8 questions

    Obstructive Sleep Apnea Symptoms Quiz 3

    StimulatingSugilite2002 avatar
    StimulatingSugilite2002
    Overview of Obstructive Sleep Apnea (OSA)
    16 questions

    Overview of Obstructive Sleep Apnea (OSA)

    emmamac avatar
    emmamac
    Anticoagulant Complications and OSA Overview
    45 questions

    Anticoagulant Complications and OSA Overview

    CelebratoryNovaculite9923 avatar
    CelebratoryNovaculite9923
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser