6) Pulmonary (Part 2) Flashcards
Virchow’s Triad
- Stasis
- Endothelial cell injury
- Hypercoagulable states
Specific risk factors for venous thromboembolism (VTE)
- Malignancy
- Immobilization
- Surgery within last 3 months
- Preexisting respiratory disease
- Prior Hx of VTE
- Chronic heart disease
Stroke - Thrombophilia
- Inflammatory triggers
Inflammatory triggers that can pose risk of VTE
- Infection
- Tranfusion
- Erythropoiesis stimulating Rx
Specific risk factors for VTE in women
- Obesity
- Pregnancy
- Hypertension
- Heavy cigarette use
- Oral Contraceptive Pills/Hormone Replacement Therapy (OCP’s/HRT)
Most common route of VTE
- LE thrombus –> IVC –> R ventricle –> pulmonary arteries
Signs and symptoms of VTE
- Dyspnea (79%)
- Tachypnea (57%)
- Pleuritic pain (47%)
- Leg edema, erythema, tenderness, palpable cord (47%)
- Cough/hemoptysis (43%)
Other possible findings in VTE
- Tachycardia
- RV gallop
- Loud P2, & prominent jugular “a” waves suggest RV failure
- Syncope or sudden death with massive PE
Typical ABG findings
- Hypoxemia (Low PaO2)
- Hypocapnia (Low PaCO2)
- Increased alveolar-arterial oxygen gradient (A-a gradient)
- 15%-20% have normal ABG’s
A-a gradient
- A measure of how effectively oxygen in your alveoli moves into your pulmonary vasculature
A-a gradient calculation
- PAO2 – PaO2
- PAO2 is calculated from the alveolar gas equation
- PaO2 is measured in the arterial blood
A-a gradient measured from the ABG results
- A-a gradient = [ (FiO2) x (Atmospheric Pressure - H2O Pressure) - (PaCO2/0.8) ] - PaO2 from ABG
- A-a gradient = [.21 x (760-47) – (PaC02/0.8) ] - PaO2
Normal A-a gradient room air
- 10 to 20 mmHg
Increased A-a gradient may be a result of
- V/Q (ventilation-perfusion) imbalance
- Anatomic shunts
- Impaired diffusion
Adjunctive studies in the evaluation of PE
- ABG’s
- EKG’s (S1Q3T3)
- CXR’s
- Echocardiograms
- Doppler (to evaluate for DVT)
- Cardiac Enzymes and BNP
Primary studies in the evaluation of PE
- D-dimer strategy combined with CT angio
- V/Q scan based strategy
- Pulmonary angiography (gold standard, but invasive)
- MRI/MRA
CXR findings in PE
- That was a “WHALE” of a PE
- W= Westermark Sign
- H =Hampton’s Hump
- A = Atelectasis
- L = Lovely (Meaning perfectly normal)
- E = Effusions
Westermark sign
- Seen on plain film radiography CRX
- Dilatation of pulmonary vessels proximal to embolism along with collapse of distal vessels (often with a sharp cut off)
Hampton’s Hump
- Pleural based opacities with convex medial margins on CRX
CRX in PE may show
- Collapse
- Consolidation
- Small pleural effusion
- Elevated diaphragm
Ultrasound
- Duplex scanning with compression will aid to detect any thrombus
- Highly sensitive and specific for diagnosing DVT
Ultrasound looks for
- Loss of flow signal
- Intravascular defects
- Non collapsing vessels in the venous system
D-Dimer
- Degredation product of crossed linked fibrin
- Detectable above 500 ng/ml in nearly all cases of VTE, but common in many other conditions (sensitive but not specific)
V/Q scanning
- Radioactive cmpd inhaled (distributes evenly in normal lung)
- Radioactive cmpd injected into vein, travels to tissues in blood vessels (no injected material in a region indicated embolus)
- “Mismatch” of inhaled and injected cmpds on lung scan images = pulmonary embolus
Acute treatment for pulmonary embolism
- Anticoagulation for most patients
Anticoagulation in acute PE Tx
- Low molecular weight heparin (IE Lovenox); Fondaparinux (Arixtra); or unfractionated heparin
- There are some new approved Oral anticoagulants for acute treatment (IE Rivaroxaban (Xaletro))
“Massive PE”
- “Massive PE” - hypotensive/unstable patient without a pulse
- If no contraindications – systemic thrombolytics
- Catheter based therapy to break up the
- Surgical Thrombolectomy
Tx for acute PE if contraindications to Anticoagulation (IE active hemorrhage, low hemagobin/hematocrit)
- IVC Filter
Long term PE Tx
- Anticoagulation (Oral) for at least 3 months
- Most continue beyond that if low bleeding risk
Bronchitis
- Usually viral, sometimes bacterial
- Non-smokers: M. pneumoniae
- Smokers: S. pneumoniae
Bronchitis symptoms
- Cough
- Fever
- Sore throat
- Rhonchi
- Wheezing
Bronchitis diagnosis
- Usually clinical
- CXR rules out other causes
Bronchitis Tx
- Rest, fluids, analgesics
- Bronchodilators/steroids may be considered
- Antibiotics show no benefit for true viral bronchitis (use only if underlying bacterial etiology or high risk patients)
Pneumonia organisms
- S. pneumoniae (pneumococcus)
- Mycoplasma pneumoniae
- Influenza
- Gram negative bacilli
- Legionella pneumonia
Pneumonia clinical features
- Fever
- Chills
- Productive cough
- Pleuritic chest pain
Pneumonia physical exam findings
- Signs of consolidation (egophony, increased fremitus)
- Bronchial breath sounds and rales/crackles over the affected areas
Pneumonia diagnostic studies
- CXR
- Labs
Labs for pneumonia diagnostic studies
- WBC normal or slightly elevated
- Sputum for gram stain and culture may detect specific organisms
- Blood cultures x 2 may detect specific organisms (especially with septicemia)
- Urine antigen test (as indicated) – highly specific for Legionella pneumonia
Community acquired pneumonia Tx
- Empiric therapy (outpatient)
- Admit if hypoxic (O2 sat < 90%, septic, etc.) for inpatient empiric therapy
Empiric therapy (outpatient)
- Amoxicillin (Streptococcus pneumonia coverage)
- Macrolides (EES, azithromycin, or clarithromycin)
- Doxycyline/Tetracycline
- Respiratory fluoroquinolones - levofloxacin [Levaquin], gatifloxacin [Tequin], moxifloxacin [Avelox]
Empiric therapy (inpatient)
- Intravenous beta-lactam (cefuroxime, ceftriaxone [Rocephin], cefotaxime [Claforan]) with a macrolide
- Intravenous respiratory fluoroquinolones
Viral pneumonia organisms
- Influenza
- Parainfluenza
- Respiratory syncytial virus (RSV)
- Adenovirus
Viral pneumonia CXR shows
- Patchy infiltrates
Viral pneumonia Tx
- Supportive care
- Flu antiviral drugs reduce duration but not severity of pneumonia caused by Influenza
Pneumonia (Pneumococcal)
- S. pneumoniae (most common in adults)
Pneumonia (Pneumococcal) symptoms
- Fever
- Chills
- Rusty sputum
Pneumonia (Pneumococcal) diagnosis
- Gram stain = gram postitive diplococci
- CXR = lobar consolidation or effusion
Pneumonia (H flu)
- Primarily seen with COPD patients
- Dx: CXR, Gram stain = gram negative coccobacilli
Pneumonia (Klebsiella)
- Seen in alcoholics, often due to aspiration
- High mortality
- S/S: “currant jelly sputum”
- Dx: CXR, gram negative bacilli on Gram stain
Pneumonia (Mycoplasma)
- “Atypical pneumonia”, seen in close quarters (military), is the most common pneumonia in younger patients
- Dx: CXR, Gram’s stain = nothing (no cell wall), positive cold agglutinin test
Pneumonia (Legionella)
- “Atypical” air conditioners, Cruise ships, hotels, etc.
- S/S: GI and CNS symptoms + fever, cough, etc
- Dx: CXR, urine antigen test is definitive
Pleural effusion symptoms
- Dyspnea
- Pleuritic chest pain
Pleural effusion clinical findings
- Dullness to percussion
- Diminished or inaudible breath sounds
- Pleural friction rub
- Decreased tactile fremitus
- Asymmetric thoracic expansion, with lagging expansion on the affected side
Some causes of pleural effusion
- Malignancy
- Pneumonia
- Heart failure
- Cirrhosis
- Nephrotic syndrome
Best next step for pleural efusion
- Thoracentesis
Pneumothorax
- Accumulation of air in the pleural space
Pneumothorax symptoms
- Sudden onset of dyspnea
- Ipsilateral chest pain
Pneumothorax physical exam findings
- Decreased or absent lung sounds (unilateral)
- Decreased thoracic expansion (unilateral)
- Decreased tactile fremitus (unilateral)
- Tachycardia
Pneumothorax CXR
- Visceral pleural line on chest radiograph is diagnostic
- Expiratory film will increase sensitivity
Primary pneumothorax
- Most commonly seen in tall slim young males, smokers, & Marfan syndrome
Primary pneumothorax Tx
- Small pneumothoraces may be managed with O2 tx and repeat observation with CXR
- Larger pneumothoraces require chest tube placement
Secondary pneumothorax
- Complication of underlying lung disease (IE COPD, Cystic Fibrosis)
- TX: chest tube
Traumatic pneumothorax
- Penetrating chest trauma
- Clinician induced (ie complication from subclavian central line placement)
- TX: chest tube
Tension pneumothorax
- Medical emergency
- TX: immediate placement of large bore needle with a catheter in the 2nd ICS MCL followed by chest tube placement when available.
