Pulmonary Review

From Iusmicm

Contents 1 Introduction 2 Approach to Shortness of Breath 2.1 Lung 2.2 Vascular 2.3 Airway 2.4 Mechanical 2.5 Miscellaneous 3 History and Physical Exam 3.1 Know the key details of the pulmonary history and physical exam 3.2 Interpret basic acid-base disorders 3.3 ABG Interpretation 3.4 Oxygenation Failure 3.5 Diagnose pneumothorax, pleural effusion, and atelectasis on exam or xray (know what to look for!) 3.6 Know how to treat a pneumothorax, atelectasis secondary to mucus plug, and pleural effusion 3.7 Know basic bronchoscopic indications 3.8 Know the objective findings in vocal cord dysfunction syndrome 4 Pulm Function Testing 5 Peds Pulmonary 6 Pneumonia 6.1 Concepts 6.2 Details 7 Pulmonary Hypertension 8 Pulmonary Embolism 9 Obstructive Airways Diseases 10 The Pleura & Neurologic Disorders 11 Interstitial Lung Disease and SPNs 12 Treatment of Respiratory Failure 13 Pulmonary & Critical Care Case Conference

Introduction

Approach to Shortness of Breath

Lung

• Interstitial Lung Disease – What is it? • Lung Nodules/Cancer (#1 cause of cancer death) – What types are there? – How are they distinguished from one another? • Pneumonia – Types, risk factors, treatment • Atelectasis (collapse of the lung) – Shallow breathing  surfactant problems – Obstruction of airway (mucus, tumor)

Vascular

• Pulmonary Hypertension – How do we diagnose it? – How do we define it? – What causes it? • Pulmonary Embolism – How do we diagnose it? – How do we treat it?

Airway

• Airway obstruction “COPD” – Asthma – Emphysema – Chronic Bronchitis • How do we diagnose it? • How do we treat it? • How do we distinguish these from one another?

Mechanical

• Neurologic ventilatory problems – How do we diagnose and treat them? • Pleural problems – What is the purpose of the pleura? – How do we define pleural effusions?

Miscellaneous

• Peds (Dr. Howenstine) – Recognize common pediatric respiratory problems • Respiratory Failure (Dr. Carlos) – What are our options for the failing patient? – When and how do we intubate patients? – Exam prep • Case Conference – Putting it all together…real life cases.

History and Physical Exam

• “One of the essential qualities of the clinician is interest in humanity, for the secret in the care of the patient is in caring for the patient.”

Know the key details of the pulmonary history and physical exam

• History:
  • Shortness of breath: When, where, how long, triggers, relievers
  • Cough: Mucus?, blood?, timing?
  • Associated conditions:
    • Chest pain, dizziness, leg swelling, dysphagia
  • Social History:
    • Pets (birds, rodents, lizards, farm animals)
    • Occupation (silica, asbestosis, fumes, metals)
    • Travel
      • Tuberculosis (remember vets ~ Vietnam)
      • Long flights = immobility (DVT, PE)
    • Smoking
      • Calculate pack/years, quit? when?
      • Ex. smoked 2ppd x 15 years = 30 pk/year history
      • Remember 2nd hand exposures!
  • Family History:
    • Tuberculosis (exposure)
    • Lung Cancer (? Genetic)
    • Rheumatic diseases
    • COPD/Emphysema
    • Alpha-1-antitrypsin (< 50 yrs old)
• Physical:
  • Inspection:
    • Nasal flaring, pursed lips, sentences, abd breathing
    • Accessory muscles (scalene, SCM contract)
    • Kyphoscoliosis, clubbing, edema
  • Palpation
    • Tactile fremitus (consolidation increases), effusion decreases
    • Trachea
  • Percussion (use your wrist!)
    • Side to side, hyper or hypo
  • Auscultation
    • Egophony (“eeee” --- “aaaa” = consolidation)
    • Listen here
    • Dullness + crackles + increased breath sounds + increased fremitus = consolidation
    • Dullness + decreased breath sounds + decreased fremitus = effusion
    • Dullness + absent breath sounds = atelectasis

Interpret basic acid-base disorders

• ABG gives you: pH, pCO2, and pO2
• Anion gap can be calculated = Na - Cl + CO2
  • Requires CO2 value from serum chemistries

• pH interpretation of ABG:
  • acute: decrease of pH by 0.08 generally indicates an increase of PaCO2 of 10 (and vice versa)
  • chronic: decrease of pH by 0.03 generally indicates an increase of PaCO2 of 10 (and vice versa)
    • includes a 5 pt bicarb rise for every 10 mm pCO2 rise
  • see table

Disorder	PaCO2	pH	HCO3	Anion Gap	Common Causes
Metabolic acidosis		low	low	up or down	MULEPAKS (AG high), HARDUP (AG normal)
Metabolic Alkalosis		high	high		contraction alkalosis, diuretics, corticoisteroids, gastric suctioning, vomiting, hypderaldosterone (Cushing's, Bartter's syndrome, severe K depletion)
Respiratory acidosis	high	low			CNS depression, chest bellows dysfxn (Guillan-Barre, MG), lung or upper airway disease (COPD, asthma, pulm edema)
Respiratory alkalosis	low	high			hypoxemia, altitude, anxiety, sepsis, pneumonia, mild asthma, early pulm edema, PE

ABG Interpretation

• ABG gives you pH, pCO2, and pO2.
  • pCO2 tells you about ventilatory problems.
  • pO2 tells you about oxygenation problems.

Oxygenation Failure

• Oxygenation failure is defined as an elevated A-a gradient.
  • A-a gradient: difference between alveolar oxygen and arterial oxygen = PiO2 - (pCO2 / R) - pO2
    • PiO2: pressure of oxygen in the inspired air; room air is 21% at 760 barometric pressure so around 150; can be diff on a ventilator.
    • pCO2: pressure of CO2 in the blood; from the ABG
    • R: respiratory quotient; assume 08
    • pO2: pressure of oxygen in the arterial blood; from ABG
  • Normal A-a gradient = (pt age / 4) + 4

• To quantify the oxygenation problem (once we have calculated an elevated A-a gradient), we compare SaO2 to PaO2 and PaO2 to FiO2.
  • SaO2 = oxygen saturation; obtained via pulse oximetry
  • PaO2 = dissolved oxygen; obtained via ABG
  • FiO2 = inspired oxygen; assumed to be 21% on room air but can be whatever you set on a mask / cannula

• SaO2 : PaO2: a measure of oxygen on hemoglobin to oxygen in the blood
  • high ratio means that....

• PaO2:FiO2 = a measure of blood oxygen to alveolar oxygne.
  • A normal PaO2:FiO2 is calculated via the A-a gradient: A-a = FiO2 - (pCO2 / R) - pO2, so FiO2 / pO2 =
  • The worse the oxygenation issue, the lower the ratio.
  • That is, the worse the ability of the lungs to move oxygen from the alveolar air to the blood, the lower the PaO2 relative to a (practically) stable FiO2.

Diagnose pneumothorax, pleural effusion, and atelectasis on exam or xray (know what to look for!)

• Pneumothorax
  • hypodense areas, lack of blood vessels, trachea deviates away from lesion
  • chest tube w/ suction to pull air off

• Pleural effusion
  • poor phrenic angles, uni/bi lateral density, decubitus view (free, loculated, fluid air level)
  • trachea deviates away from lesion
  • hemithorax on lesion side increases
  • dullness, decreased breath sounds on lesion side
  • decreased fremitus on lesion side
  • thoracentesis

• Atelectasis
  • trachea shifts toward side with atelectasis
  • hemithorax decreases on lesioned side
  • clear mucus plug with bronchoscopy

Know how to treat a pneumothorax, atelectasis secondary to mucus plug, and pleural effusion

• see above

Know basic bronchoscopic indications

• Indications for bronchoscopy:
  • Bronchoalveolar lavage (cultures, cell counts)
  • Evaluate for bleeding or obstruction or burn
  • Clear out mucus plugs “a snot bronch”
  • Biopsy of lung lesion
  • Biopsy of lymph node (EBUS)
    • Mediastinal staging of cancer
    • Diagnosis of sarcoidosis, histoplasmosis, cancer

Know the objective findings in vocal cord dysfunction syndrome

Pulm Function Testing

Peds Pulmonary

Pneumonia

Concepts

• Time of onset informs the likely causative agent:
  • 0-2 days: bacterial
  • 0-2 days: mycoplasma, viral, legionella, pneumocystis, fungal
  • chronic: anaerobic, mycobacterial, fungal, nocardia, actinomycosis

• Distribution informs the likely causative agent:
  • Lobar: bacterial, anaerobes
  • Diffuse: viral, pneumocystis, mycoplasma, fungal
  • Nodular / cavitary: mycobacterial, fungal, anaerobes

Details

• Workup for the pt with pneumonia:
  • H&P
  • CBC, electrolytes, glucose, BUN / Cr, LFTs
  • ABG, puls oximetry
  • Chest radiograph
  • Sputum gram stain, sputum culture (2 days)
  • Blood culture x2 (hospitalized pts, only)
    • Legionella
    • Fungi
    • Mycoplasma
    • Respiratory viral titers
  • Thoracentesis

Pulmonary Hypertension

Pulmonary Embolism

Obstructive Airways Diseases

• Know the components of COPD (asthma, chronic bronchitis, emphysema) and their defining characteristics including:
  • Basic pathophysiology
  • Symptomatology
  • Diagnostic studies
  • Classifications (asthma & emphysema)
  • Treatment strategies (asthma & emphysema)
  • Factors indicating poor prognosis (emphysema)
  • Management goals (asthma)

The Pleura & Neurologic Disorders

• Recall the anatomy and physiology of the normal pleural space
• List the signs and symptoms of pleural effusion and pneumothorax
• Identify pathophysiologic causes of an effusion or pneumothorax
• Differentiate a transudative from an exudative effusion
• Identify the characteristics of pleural fluid analysis in common pleural diseases
• Identify the pulmonary function abnormalities associated with neuromuscular weakness
• List those neuromuscular diseases associated with respiratory failure

Interstitial Lung Disease and SPNs

Treatment of Respiratory Failure

• Be able to calculate the A-a gradient given an ABG and FiO2
• Define Shunt & V/Q Mismatch (increased and decreased)
• Know what influences the Oxygen dissociation curve to the right and left
• Learn the types and FiO2’s of various supplemental oxygen devices
• Understand the types and indications for Non-invasive positive pressure ventilation
• Understand the procedure of endotracheal intubation and indications for mechanical ventilation
• Learn basic mechanical ventilation (not covered on exam)
• Review for the Pulmonary Exam

Pulmonary & Critical Care Case Conference

• Introduce you to “real-world” clinical medicine through actual case studies
• Cases not on exam