Ventilation & Gas Exchange (Ch. 31)-- Term First Flashcards
Exam 2
Traumatic Pneumothorax
Chest Injury (penetrating or non-penetrating)
- fractured or dislocated ribs
- CPR
- Central line insertion
- Intubation
- Positive pressure ventilation
Acquired Atelectasis
Adults
- Airway obstruction
- Lung compression– tumor, exudate, pneumothorax
risk factors– sedation, pain, narcotics, immobility
Atelectasis Clinical Manifestations
⇡ RR, ⇡ HR, dyspnea, cyanosis, hypoxemia, decreased chest expansion, absent breath sounds, intercostal retractions
Prevention– incentive spirometer, frequent position changes, ambulate, hydrate
Treatment– fix cause, supplemental O2
Shunt
Perfusion without ventilation (LOW V/Q)
- Hypoxemia
- Atelectasis
- PNA
- Asthma
- COPD
- Chronic bronchitis
- Emphysema
Hypercapnic/Ventilation Failure
PaCO2 > 50 mmHg AND pH <7.30
Causes– ⇣ RR or WOB
- Upper airway obstruction– infection, laryngospasm, tumors
- Weakness or paralysis of respiratory muscles– brain injury, sedation, drug overdose (opioids), Guillen-Barre syndrome, Muscular Dystrophy, spinal cord injury
- Chest wall injury– physiologic dead space
Leads to– Vasodilation (systemic circulation), Pulmonary blood vessel constriction
Diagnosis
- ABG– elevated CO2
Chronic Bronchitis Clinical Manifestations
- Cyanosis
- Fluid retention
- R-sided HF (cor pulmonale)
- Productive cough
- ⇣ RR
-
Crackles and wheezes
- d/t mucus in the lungs
Inflammatory Mediators
Histamine, leukotrienes, prostaglandins → Bronchoconstriction
Transudate
Clear, thin fluid (hydrothorax), specific gravity <1.020
d/t– CHF, renal failure, nephrosis, liver failure, malignancies (cancer)
Emphysema Clinical Manifestations
-
Accessory muscle & pursed-lip breathing
- ⇡ positive pressure
-
Barrel chest
- d/t air trapping
- ⇣ Breath sounds
- ⇡ RR
- Non-productive cough
- NO cyanosis
Asthma Attack Triggers
- RTIs
- Exercise (EIB)
-
Drugs
- ASA– ⇣ COX, ⇡ LOX → ⇡ Leukotrienes
- Morphine– Histamine release
- Emotional Upset
-
Bronchial irritants
- Smoke
- Toxins
Late Phase Response
Extrinsic/Allergic/Atopic Response
- 2-8 hrs. after exposure
- Mucosal edema, ⇡ secretion, ⇡ WBC, epithelial damage, bronchospasm
- Lasts several days
Treatment– Corticosteroids (ICS)
Cystic Fibrosis Pathogenesis
-
Cl- unable to move into epithelial lumen of airway
- Cl- remains w/i cell
- Na+ & H2O move from airway into blood
- Respiratory secretions thicken
-
⇣ H2O in mucous membranes
- Dehydration
-
Accumulation of mucus
- Airway obstruction
- Pancreatic & biliary duct dysfunction
- Pancreatic enzyme deficiency
- Vas deferens dysfunction
- Azoospermia
- Increased risk of pulmonary infection
High V/Q
High V, Low Q (100:1)
- Dead air space
- Low flow states
- Pulmonary embolism (PE)
Hyperventilation
⇣ CO2 in the arterial blood → Hypocapnia/Hypocarbia → Respiratory Alkalosis
d/t– Panic attack, pain, ⇡ RR, hypoxemia
Respiratory Failure Manifestations
- Inadequate gas exchange
- V/Q mismatch
- PaO2 < 60 mmHg or PaCO2 > 50 mmHg & pH <7.30 or BOTH
- Severe Hypoxemia + Hypercapnia + Respiratory Acidosis
- Post-Surgery
- Atelectasis
- PNA
- Pulmonary edema
- Pulmonary emboli → Respiratory failure
- Smoking + lung Disease
- Underlying disease/infection
- Renal, cardiac, neurologic, or hepatic
Asthma Treatment
Limit exposure to allergens
Pharmacologic Agents
Immediate
-
Bronchodilator
- Albuterol (SABA)
-
Anti-Inflammatory
- Corticosteroid (ICS)
Long-Term
- Mometasone (ICS)
- Salmeterol (LABA)
- Symbicort– Combination (LABA + ICS)
Pleural Effusion
Collection of fluid in the pleural cavity
Acute Lung Injury (ALI)
Sudden inflammation that starts at the lungs → Disruption of gas exchange at alveolar-capillary membrane
-
Hypoxemia
- Less severe form
Exudate
Purulent, thick fluid, specific gravity >1.020
d/t– elevated LDH & protein, inflammatory cells
Hypoxemic/Oxygenation Failure
PaO2 < 60 mmHG d/t problem with O2 uptake
Causes– COPD, severe PNA, Atelectasis, ARDS, Pulmonary edema, V/Q mismatch (d/t shunt, dead air space…)
- Decreased O2 to alveoli (d/t high altitude or hypoventilation)
-
Impaired diffusion of O2 from alveoli to blood (d/t V/Q mismatch or alveolar-capillary impairment)
- Vasodilation (Systemic circulation)
-
Inadequate circulation through pulmonary capillaries (d/t pulmonary embolus or arteriovenous malformation)
- Pulmonary blood vessels constrict
Tension Pneumothorax
Air stuck in pleural space (intrapleural pressure > atmospheric pressure)
Leads to–
- compression atelectasis
- trachea and sternum shift L
- L lung shift
- Vena cava compression
- ⇣ venous return
- ⇣ cardiac output
Dead Air Space
Ventilation without perfusion (HIGH V/Q)
- Hypoxemia
Pneumothorax
Air in pleural space → ⇡ Pressure → Partial or complete lung collapse
Bronchial Asthma Types
Chronic inflammation of airway → airflow obstruction & airway hyperresponsiveness
-
Extrinsic/Allergic/Atopic
- Type I IgE-mediated hypersensitivity reaction
- Genetic component
-
Intrinsic/Non-allergic/Non-Atopic
- no allergy component
Pulmonary Embolism Risk Factors
Virchow Triad
-
Venous stasis (slowing) & Venous endothelial injury
- Bed rest, hip or femur fracture, surgery, childbirth, MI, HF, spinal cord injury
-
Hypercoagulability states
- Cancer
- Pregnancy
- HRT
- Oral contraceptives
Types of Respiratory Failure
- Hypoxemic– Oxygenation Failure
- (PaO2 < 60 mmHg)
- COPD
- PNA
- Atelectasis
- Impaired diffusion
- Pulmonary edema
- ALI/ARDS
- Hypercapnic/Hypoxemic– Ventilation & Oxygenation Failure
- (PaO2 < 60 mmHg, PaCO2 > 50 mmHg & pH <7.30)
- Upper airway obstruction
- Infection
- Laryngospams
- Weakness or paralysis of respiratory muscles
- Brain injury
- Overdose
- Guillain-Barre
- Muscular Dystrophy
- Spinal Cord Injury
- Chest wall injury
- Upper airway obstruction
Diagnosis– ABGs (determine if hypoxemic, hypercapnia or BOTH)
Pneumothorax Clinical Manifestations
Hypoxemia, ⇡ RR, absent breath sounds, dyspnea, chest asymmetry
Treatment– Fix cause, supplement O2, thoracentesis (large needle aspiration)
Tension– ⇡ HR, ⇣ cardiac output, shock, tracheal deviation (treat w/ chest tube)
Hypoxemia
Reduced oxygenation of arterial blood
- Always leads to reduced oxygenation of cells in tissues
Pulmonary Embolism Clinical Manifestations
-
Small emboli
-
Asymptomatic
- Not usually
-
Asymptomatic
-
Moderately-sized emboli
- Rapid, shallow respirations
- Pleuritic pain
- Cough
- Blood-streaked sputum
-
Massive emboli
- Sudden collapse
-
Crushing substernal chest pain
- Can be confused w/ MI
- Shock
- LOC
- Rapid, weak pulse
- Hypotension
- Distended neck veins (JVD)
- Cyanosis
- Fatal
Sympathetic Stimulation
Beta-adrenergic receptors → Bronchodilation