Pulmonology Basics Flashcards
Lung Mechanics
- Initiation of breathing: Diaphragm contracts downwards causing more - intrathoracic pressure relative to the atmosphere, allowing air into chest
- Exhalation is passive during tidal breathing as the lungs and chest wall move toward their equilibrium positions
- During forceful breathing & hyperventilation, abdominal muscles help force air out of the lungs
Compliance
- The change in volume for a given change in pressure of a system
- Compliance of the lung changes with lung volume
- As lung volume increases, lung compliance decreases
Resistance
- An important determinant of airflow
- Total airway resistance is in part a function of lung volume
- At lower volumes, small airways tend to collapse and total resistance is higher
- At higher lung volumes, small airways are pulled open
Ventilation-Perfusion Relationships
- The balance between ventilation (V) and perfusion (Q) in the lung is critical in determining the final oxygen content of the blood that returns to the left side of the heart from the lungs
- -Ventilation is regulated by respiratory control centers in the pons/medulla (peripheral chemoreceptors –> lungs)
- -Disorders of V are not always caused by primary lung pathology
Pulmonary Blood Flow
- Pulmonary vasculature constricts in areas of low oxygen tension, resulting in less blood flow to areas with little-no ventilation
- Works to improve overall V/Q matching
Lungs: Fetal/Perinatal
- Fetus: Lungs are filled with fluid-respiratory exchanges occur via the placenta
- After birth, alveoli inflate & start functioning in gas exchange (fully @ 2 wks.)–this relies on surfactant
- RR in newborns = 40-80 breaths/min.
Lungs: Infancy - 1 year
- Airways shorter, narrower, less stable & easily obstructed
- Lung tissue is fragile & prone to barotrauma
- Fewer alveoli w/ decreased collateral ventilation
- Accessory muscles immature, susceptible to early fatigue
- Chest wall less rigid
- Diaphragmatic breathing
- Rapid RR = ~30/min. (leads to rapid heat & fluid loss)
*Pulmonary disease accounts for 50% of deaths in children < 1 year
Lungs: 1-5 years
- Terminal airways continue to branch
- Alveoli increase in number
- RR @ 5 years = ~25/min.
Lungs: Children to Adolescents
- Lungs mature throughout childhood, with more alveoli forming until young adulthood
- If smoking is initiated during this period, the lungs may never fully develop
*Pulmonary disease accounts for 20% of hospitalizations in children < 15 years
Lungs: 20-60 years
**RR = 16-20/min. (20-40 years) - Develop lifelong habits & routines - Optimal physical performance (41-60 years) - Body still functioning at high level with varying degrees of degradation
Lungs: > 60 years
- RR depends on physical and health status
- Changes in mouth, nose, and lungs
- Metabolic changes lead to decreased lung functioning
- Muscular changes
- Diffusion through alveoli diminishes
- Lung capacity diminishes
- Coughing becomes ineffective
Respiratory Symptoms
Primary:
- Cough
^ Acute cough = cough lasting < 3 weeks
^ Chronic cough = cough lasting > 8 weeks
- Dyspnea
- Hemoptysis–Cough with expectoration of bloody sputum or blood
^ Scant (mild) = < 20 mL in 24 hours - blood streaks w/ expectorated phlegm
^ Submassive (moderate) = 20-250 mL (less than 1 cup) in 24 hours
^ Massive (severe) = > 250 mL (more than a cup) in 24 hours - life threatening (admit)
Prevalence of Disease Causing Coughing
Chronic allergic rhinitis or PND - 41% Asthma - 24% GERD - 21% COPD & chronic bronchitis - 5% Bronchiectasis - 4% Lung Cancer - < 2% Medication-induced - 5-25% Idiopathic/Psychological - < 5 % (Others, such as CHF)
Alarming Pulmonary Symptoms
- Hemoptysis
- Fever + purulent sputum production
- Wheezing + dyspnea
- Chest pain
- Excessive chronic sputum
- Unintentional weight loss
- Dyspnea + lower extremity edema
Causes of Hemoptysis
Serious:
- Lung cancer
- Tuberculosis
- Pulmonary embolism
- Pneumonia
- Alveolar hemorrhage syndrome
- Lung abscess (MC)
Benign:
- Acute viral or bacterial bronchitis
- COPD exacerbation
- Bronchiectasis
MCCs: Acute or chronic bronchitis, pneumonia, tuberculosis, lung cancer
Others: bronchiectasis, PE, trauma, fungal infection, foreign bodies, rheumatologic disease
*Must differentiate between true hemoptysis versus bleeding from the upper airway or GI tract
Causes of Fever + Purulent Sputum Production
Serious:
- Pneumonia
- Lung abscess
Benign:
- Acute sinusitis
Causes of Wheezing + Dyspnea
Serious:
- Asthma
- COPD exacerbation
- Heart failure
Benign:
- Acue bronchitis
Causes of Pulmonary Related Chest Pain
Serious:
- Pulmonary embolism
- Acute coronary syndrome
Benign:
- COPD exacerbation
Causes of Excessive Chronic Sputum
Serious:
- Bronchiectasis
- Lung abscess
- Lung cancer
Benign:
- Chronic bronchitis
- Chronic sinusitis
Causes of Pulmonary Related Unintentional Weight Loss
Serious:
- Lung cancer
- Tuberculosis
- Lung abscess
Causes of Dyspnea + Lower Extremity Edema
Serious:
- CHF
- Pulmonary embolism
Cough History
HPI: Onset, duration, frequency, associated sxs, precipitating and/or alleviating factors, changes over time**
ROS: F/C, weight changes, night sweats, upper/lower respiratory tract (post-nasal drip –> allergic, vasomotor, nonallergic rhinitis), cardiovascular system, digestive tract (heartburn, bitter taste –> GERD)
SH: Smoking (tobacco and other), alcohol (aspiration, increased cancer risk), diet, environmental and occupational exposures
PMH: Current & prior medications (i.e., ACEIs), allergies, asthma, atopic dermatitis, sinusitis (recent respiratory infections), tuberculosis exposures, CAD, esophageal disease
Quality of Cough - DDx
- Dry cough –> GERD, irritant cough, post-viral infection, pulmonary fibrosis
- Clearing throat frequently –> UACS, allergic vasomotor, nonallergic rhinitis
- Worsening overtime –> bronchitis, asthma, CHF, lung cancer, bronchiectasis
- Worse w/ particular season –> UACS, asthma
- Lingered after a recent cold/flu –> post-infectious cough, UACS
Associated Sxs - DDx
- Quality/Quantity of sputum (color, amount, consistency, changing?)
- DOE –> asthma, CHF, COPD
- Wheezing –> asthma, CHF
- Hoarseness –> GERD, chronic laryngitis, laryngeal nodules/polyps, UACS
- Burning in throat at night or early morning –> GERD
- PND (Post-nasal drip) –> UACS, sinusitis
- Seasonal –> asthma, UACS, allergic rhinitis
- Halitosis or sinus pain –> chronic sinusitis
- Orthopnea or nocturnal dyspnea –> CHF, obstructive sleep apnea, GERD, COPD
Cough Modifying Factors - DDx
- During/after exercise or cold exposure –> asthma, UACS, allergic/vasomotor rhinitis
- Worse in supine –> UACS, GERD, CHF, bronchiectasis, acute bronchitis
- Worse at night –> asthma, GERD, CHF
- Triggered by position changes –> bronchiectasis, CHF
- Improved with OTC antihistamines –> allergic rhinitis, UACS
Chronic Cough Causes
Often caused by multiple contributing factors
- MCCs:
^ GERD, UACS, & asthma account for 90% of chronic cough in non-smokers
^ Chronic cough occurs in 5-25% of patients taking ACEIs
^ Pt’s with alarm symptoms require prompt evaluation
Pulmonary Labs and Tests
- CXR
- Sinus imaging (CT)
- Pulmonary function tests
- Barium esophagography
- 24-hour esophageal pH monitoring
- WBC w/ differential
- Direct laryngoscopy
- Fiberoptic bronchoscopy
- Bronchoscopy (if > 40, tobacco hx, cancer hx, hemoptysis lasting > 1 week)
- Consider referral (i.e., ENT)
Dyspnea Terminology
Dyspnea–abnormally increased awareness of breathing or sensation of difficulty breathing
Orthopnea–dyspnea when laying flat
Paroxysmal nocturnal dyspnea (PND)–dyspnea that wakes the pt from sleep
Platypnea–dyspnea that improves when the pt lies down
Trepopnea–dyspnea that occurs in the lateral decubitus position on one side, but not the other
Dyspnea Causes
Pulmonary Cardiac Hematologic (i.e., anemia) Chest wall or neuromuscular disease Metabolic (i.e., acidosis) Functional (i.e., panic disorders, anxiety) Deconditioning
Cardiovascular Causes of Dyspnea
Muscle – cardiomyopathies
Vessels – ischemia, pulmonary HTN
Valves – regurgitation, stenosis, infection
Pulmonary Causes of Dyspnea
Bronchi -- mass, foreign body Bronchioles -- asthma, chronic bronchitis Interstitial lung disease Alveoli -- emphysema, chronic pneumonia Vessels -- chronic pulmonary emboli Pleura -- effusions Lung cancer
Causes of Acute Dyspnea
- Flash pulmonary edema
- Pulmonary embolism
- Anaphylaxis
- Aspiration
- Cardiac tamponade
- COPD exacerbation
- Acute pneumonia
- Respiratory muscle weakness
- Spontaneous pneumothorax
- Metabolic acidosis
Alarm Symptoms of Dyspnea
Acute onset & rapid progression may lead to respiratory failure
- Pleuritic CP –> PE, pneumothorax, pneumococcal pneumonia
- Lip swelling, hives, & wheezing –> anaphylaxis or angioedema
- Substernal CP –> acute MI or ischemia
- Pink, frothy sputum –> cardiogenic pulmonary edema
- Fever + sputum production –> acute pneumonia
- Fever + signs of infection or shock –> acute respiratory distress syndrome
- Fever + sore throat, dyspnea, & hoarseness –> epiglottitis
- Ascending weakness –> Gullain-Barre syndrome
- Generalized weakness –> Myasthenis gravis
- Known or suspected DM or CKD –> diabetic ketoacidosis or metabolic acidosis
- Suicidality or chronic pain –> ASA overdose
Dyspnea Risk Factors
- Hx of CHF, MI, CAD, DM, HTN, or hypercholesterolemia
- Smoking
- Occupation (toxin, organic material, chemicals)
- Prolonged immobilization, OCPs
- Travel
- Known allergies
- Medications
HPI: Dyspnea
- CP
- Itching/hives –> anaphylaxis
- Fever
- Cough
- Swelling in legs or abdomen
- Weight loss
- Syncope –> primary/secondary pulmonary HTN
- Joint pain
- Weakness
- Numbness in fingers –> panic attack or anxiety disorder
HPI: Hemoptysis
- Scant to moderate w/ sputum (i.e., bronchitis)
- Hoarseness, smoking, cancer history
- Severe or recurrent pneumonia or TB, chronic massive sputum production (i.e., bronchiectasis)
- Fever (i.e., pneumonia, lung abscess)
- Massive sputum for short time (i.e., pneumonia)
- Cough, fever, dyspnea, arthralgias, or rash (i.e., SLE or other collagen vascular disease)
- Hematuria
- Sinusitis
- Otitis
- Skin lesion
- TB or HIV exposure/history
- Acute CP w/ dyspnea, recent immobilization or surgery (i.e., PE)
PMH: Hemoptysis
Cancer, DVT, CV disease, liver disease, peptic ulcer disease, CKD, transplantation, HIV, vascular surgeries, tracheotomy, COPD, recent travel, IV drug use, occupational exposure, recent bronchoscopy or pulmonary surgery
Normal Function of Mucous & Sweat
- Sweat cools the body
- Mucous lubricates the respiratory, digestive, & reproductive systems
- Prevents tissues from drying out
- Protects against infection
Risk Factors for Infectious Respiratory Disease
- Low SES
- Exposure to secondhand smoke
- Low birth weight
- Bottle feeding vs. breast feeding
- Overcrowding
Bronchoscopy
- Technique used to visualize the inside of the airways
- Can be both diagnostic & therapeutic
- Typically done to look for suspicious abnormalities (e.g. foreign body, tumor, bleeding)
Flutter Valves
- Vibrates the airways (loosens mucus from the airway walls)
- Intermittently increase endobronchial pressure (helps maintain the patency of the airways during exhalation to prevent mucus trapping as it moves up)
- Accelerates expiratory airflow (facilitates upward movement of mucus through the airways; enhances clearing)
Flutter Valves
- Vibrates the airways (loosens mucus from the airway walls)
- Intermittently increase endobronchial pressure (helps maintain the patency of the airways during exhalation to prevent mucus trapping as it moves up)
- Accelerates expiratory airflow (facilitates upward movement of mucus through the airways; enhances clearing)
Oscillation Vest
- Uses a compressor to inflate/deflate at timed intervals (high frequency)
- Thins airway mucus to facilitate its removal by coughing
Oscillation Vest
- Uses a compressor to inflate/deflate at timed intervals (high frequency)
- Thins airway mucus to facilitate its removal by coughing
Oscillation Vest
- Uses a compressor to inflate/deflate at timed intervals (high frequency)
- Thins airway mucus to facilitate its removal by coughing
