1. +
Board Review: Pulm and
Critical Care
Carrie Clark DO

2. +
Respiratory Physiology

A-a gradient

=PAO2-PaO2

PAO2 value from alveolar gas equation


Alveolar gas equation: PAO2=150-(1.25xPaCO2) (at sea level
and room air)
PaO2 obtained from ABG

3. +
Hypoxemia

Defined as PaO2<60mmHg

Etiology


V/Q mismatch
 Airspace not being perfused OR perfused areas not being ventilated
 Etiologies: asthma, COPD, PE, interstitial lung disease
 Management: oxygen and treat underlying cause
Shunting
 Decreased diffusion of oxygen
 Etiologies: alveolar collapseARDS, also from alveolar filling
(pneumonia, pulmonary edema)
 Management: does NOT respond well to oxygen responds better
to PEEP

4. +
Hypoxemia

Decreased diffusion



Etiologies: thickening of alveolar/capillary interface (commonly
interstitial lung disease)
Management: responds to O2
Hypoventilation



Lack of respiratory effort resulting in low PaO2 and high PaCO2,
commonly from drug overdose
Normal A-a gradient
High Altitude

Decrease in partial pressure of available O2

Normal A-a gradient

5. +
Critical Care: ARDS

Acute onset of alveoli edema caused by capillary membranes
injury and increased permeability

Sepsis, acute pulmonary infection, DIC, shock lung, freebase
cocaine smoking

You will see bilateral infiltrates on chest x-ray

Ratio of PaO2/FiO2<200mmHg

Symptoms: respiratory distress, hypoxemia unresponsive to
increasing supplemental O2

Onset is often within the first 2 hours of inciting event, but it can
be delayed as long as 1-3 days

6. +
Critical Care: ARDS

Management

35-50% mortality

Treat underlying disease

Mechanical ventilation with PEEP

Use low tidal volumes to prevent barotrauma
Steroids NOT shown to be beneficial

7. +
Disorders of Pleura, Mediastinum
and Chest Wall

Mediastinitis

Pneumomediastinum

Pleural Effusion

Pneumothorax

8. +
Mediastinitus

Inflammation of the mediastinum

Etiology



Mixed organisms but most commonly Streptococcus and
Bacteroides
Esophageal rupture most common cause (foreign body ingestion or
stuck fish bone may accompany history or esophageal inj)
Risk Factors


Immunocompromise and diabetes, drug abuse
Symptoms

Fever, dyspnea, pleuritic, retrosternal chest pain, sub-q emphysema
of neck and chest

9. +
Mediastinitis

Diagnosis


Soft tissue x-ray of the neck may show precervical or
retropharyngeal air/edema


A CXR may show a widened mediastinum
CT should be performed to further evaluate soft tissue spaces
Management

Broad-spectrum antibiotic therapy

ENT and cardiothoracic consult

10. +
Pneumomediastinum

Etiology

Spontaneousextremely rare, blunt chest trauma, endoscopy,
obstructive lung disease

Considerer Boerhaave syndrom if h/o vomiting

Valsalva maneuver (foreceful cough against a closed glottis,
consitpation)


Observed in crack cocaine users
Symptoms

Chest pain and dyspnea

Signs: sub-q emphysema and Hamman sign (crunching, rasping
sound, synchronous with heartbeat)

Decreased cardiac output if tension pneumomediastinum is present

11. +
Pneumomediastinum

Diagnosis


Esophagogramperform in right lateral decubitus position, use a
water-soluble contrast, if clinical suspicions remain high and the
initial study is negative, repeat study with oral barium contrast

Esophagoscopyfor suspected esophageal rupture in acute
traumatic rupture


CXRreveals free air within the mediastinum, air posterior to
sternum and posterior to the heart on lateral film
Bronchoscopyfor suspected bronchotracheal tree rupture
Management

Should be admitted and observed for signs of serious complications

Broad-spectrum antibiotics for suspected esophageal rupture

12. +
Pleural Effusion

Collection of fluid within pleural space

Epidemiology



CHF is the most common cause followed by malignancy, bacterial
pneumonia, and PE
TB is the most common etiology of pleural effusion in developing
countries
Etiology

TransudativeCHF, cirrhosis with ascites, nephrotic syndrome, PE

ExudativeCancer, infectious (pneumonia, empyema, abscess,
TB), inflammatory (SLE, pancreatitis, RA, and PE

13. +
Pleural Effusion

Symptoms


Dyspnea and pleuritic chest pain, decreased breath sounds on
auscultation, dullness to percussion
Diagnosis



CXR: AP XR demonstrates effusion when pleural fluid volume
approaches 150cc
CT or US most sensitive
Thoracentesis necessary when etiology is unclear
 Light criteriaa single positive criterion is enough to classify the fluid
as an exudate
 Glucoselow pleural fluid levels (<25)=RA, TB, empyema, and
malignancies
 pHlow pH=inflammatory and infiltrative processes (empyema,
malignancies, TB, esophageal rupture)
 Amylasehigh amylase (>200) pancreatitis, malignancy, rupture

14. +
Pleural Effusion

Light Criteria
Transudate
Exudate
Pleural and
serum Protein
<0.5
>0.5
Pleural and
serum LDH
<0.6
>0.6
Pleural LDH
<200
>200

15. +
Pleural Effusion

Management

Treat underlying cause

Therapeutic thoracentesis for patients dyspneic at rest

Thoracotomy tube placement for empyema

16. +
Pneumothorax

Etiology



Spontaneousno underlying lung disease
 Male:female 6:1
 Young, tall, thin
 Smoking 20:1
 Valsalva
 Ruptured bleb
 Many recur (20-50%)
Secondary-caused by underlying lung disease
 Asthma, COPD, neoplasm
 Marfan, Ehlers Danlos, Cystic fibrosis
 Penumonia, especially with abscess or cavitation
 HIV-PCP
Tension pneumo

17. +
Pneumothorax

Symptoms





Dyspnea and pleuritic chest pain
Decreased breath sounds and hyperresonace to percussion
JVD and hypotension
Tracheal deviation away from affected side
Diagnosis


Pneumothorax
 CXR for simple pneumothorax (end expiratory for highest sensitivity)
 CT test of choice for supine trauma patient
Tension pneumo
 Clinical diagnosis
 Tracheal deviation away from affected lung
 Hypotension
 Do NOT wait for x-rays before treating

18. +
Pneumothorax

Management

Small, stable ptx (<10%)


Reabsorb 5-7% per day


100% O2
Stable patient with a small ptx can be discharged with next day
follow up after 6 hours observation and stable x-ray
Large ptx



100% O2
Tube thoracostomy
Tension ptx

Immediate decompression followed by chest tube

19. +
Noncardiogenic Pulm Edema

Definition: radiographic evidence of alveolar fluid accumulation
without hemodynamic evidence of a cardiogenic etiology (ie
pulmonary capillary wedge pressure <18mmHg)

Etiology

ARDS

High-altitude pulmonary edema

Reexpansion pulmonary edema



Large volume thoracentesis (>1L)
Rapid lung re-expansion of ptx, especially when it has been
collapsed for >3 days
Drug induced (meprobamate, opiates, naloxone, PCP, Salicylate)

20. +
Obstructive Lung Disease

Asthma and reactive airway disease

COPD

Cystic Fibrosis

21. +
Asthma and reactive airway disease

Chronic inflammatory disorder of the small airways characterized
by reversible obstruction

Etiology and patho





Airway inflammation/bronchial wall edema leading to decreased airway
diameter
Airway hyperreactivity, smooth muscle contraction
Secretions forming mucous plugs
Chronic inflammation leads to lung remodeling
Symptoms



Dyspnea with or without cough
Prolonged expiratory phase with predominantly exp wheezing
Severe exacerbations may present with absence of wheezing, inability
to speak, pulses paradoxus and hypoxia

22. +
Asthma and reactive airway disease

History associated with higher mortality

>2 hospitalizations during past year

>3 ED visits during past year

Prior intubation or ICU admission

Use of 2 or more adrenergic canisters per month

Current use of systemic steroids or recent withdrawal

Low socioeconomic class

23. +
Asthma and reactive airway disease

Diagnosis


Bedside spirometrypeak flow to monitor response to beta-agonist
treatment
 Peak flow <50% indicates severe exacerbation
Treatment




Oxygen to keep O2>88%
Beta agonistsrelaxation of bronchial smooth muscle
Epinephrine (1:1000)reserved for severe exacerbations, is
administered sub-q 0.3 q20-30 minutes up to three doses
Terbutaline reserved for severe exacerbations given SC 0.25mg
every 20-30 min up to three doses
 Longer duration of action than epinephrine

24. +
Treatment cont.

Corticosteriodsused in both acute and chronic setting to
prevent late phase inflammatory response

Oral dosing as effective as IV administration

Magnesiumbenefit in severe exacerbation

Mechanical ventilation

Avoid air-trapping or auto-peep

Smaller tidal volumes

Keep rate low

Consider increasing peak inspiratory flowlonger expiratory time

25. +
Treatment cont

When treating pregnant asthmatics…

Fetus more susceptible to hypoxia than mother

No contraindications to use of beta agonists, corticosteroids and
anticholinergics

Chronic steroids may result in lower birth weights

Epinephrine is teratogenic during first trimester and associated with
preterm delivery

26. +
COPD

Progressive partially reversible limitation of airflow

Caused by two processeschronic bronchitis and
emphysema, which occur together in most patients

Epidemiology


The single most important risk factor for COPD is smoking
Etiology

80% of acute COPD exacerbations are of infectious origin

Streptococcus pneumoniae, Haemophilus influenzae, or
moraxella catarrhalis

27. +
COPD

Signs and symptoms



Dyspnea on exertion, tachypnea, cyanosis, agitation, apprehension,
and hypertension are indicative of hypoxia
Wheezing, rales, rhonci, prolonged expiratory phase, pursed-lip
breathing and clubbing of digits
Diagnosis




Elevated hematocrit 2/2 chronic hypoxia
ABG: mild to moderate hypoxemia without hypercapnea in early
stages
CXRhyperinflation, flattened diaphragm, long narrow heart
shadow
EKGa-fib, multifocal atrial tachycardia, cor-pulmonale (tall pwaves), right axis deviation and right ventricle hypertrophy

28. +
COPD

Management

Supplemental oxygen reduces mortality in patients with advanced
COPD with room air O2 saturaion <88%

Nebulized anticholinergics

Bronchodilators

Antibiotics

First line choices include amoxicillin, cefaclor, fluoroquinolones, or
bactrim

Gram-negative infections more likely in those with frequent
exacerbation and need a third-generaltion cephalosporin

corticosteroid

29. +
Cystic Fibrosis

Most common in Europeans and Ashkenazi Jews

Autosomal recessive mutation



Abnormalities in chloride transport in exocrine tissues leads to
multiorgan involvement
Thick, viscous secretions in lungs, intestine, pancreas, and
reproductive tract
Symptoms and signs

Respiratory manifestationsmost common, exacerbations
characterized by increased cough, sputum production, decreased
lung function

30. +
CF symptoms and signs cont.

Undiagnosed patients may present with failure to thrive chronic
cough, repeated pulmonary or sinus infections, chronic
diarrhea from pancreatic insufficiency

Alternative presentations

Increased salt content in sweat gland secretion

Meconium ileus in neonates

Steatorrhea from pancreatic enzyme insufficiency

Intestinal obstruction

Spontaneous pneumo

Chronic pancreatitis

Hepatobiliary disease

31. +
CF diagnosis

Electrolytes


Hyponatremia and alkalosis
CXR

Bronchiolar thickening, hyperinflation, and patchy, diffuse infiltrates

Newborn screening

Chloride sweat testing or genetic testing

32. +
CF Management

Broad-spectrum antibiotics

Cover Staph aureus, H. flu, and double cover Pseudomonas

Chronic colonization with pathologic bacteria and chronic antibiotic
use leads to resistant organisms requiring intravenous vanco,
tobramycin, meropenem, cipro, and piperacillin

Mucolytics

Bronchodilators

Aggressive chest physiotherapy

Provide O2

Consult Pulm

33. +
Restrictive Lung disease

Loss of lung compliance resulting in volumes loss

Interstitial Lung Disease


Idiopathic pulmonary fibrosis
Sarcoidosis

34. +
ILD

ILD


Restrictive pulmonary dysfunctions with the common end-point of
interstitial collagen deposits and scarring
Idiopathic pulmonary fibrosis

50% of ILDs

Likely autoimmune

Symptoms and signsdyspnea, cough, fine dry crackles, clubbing
of fingers

DiagnosisCXR has honeycombed lungs, CTground glass
opacity

Management corticosteroids, immune modulators, lung transplant

35. +
Sarcoidosis

Epidemiology



African americans>caucasians
females>males
Etiologytypical finding includes non-caseating granuloma,
which is composed of T-helper cells and other inflammatory
cells

36. +
Sarcoidosis

Symptoms and Signs

Most patients are asymptomatic

Disease is fatal in 10% of patients because of extensive organ
involvement

Constitutional symptomsfever, fatigue, weight loss, polyarthritis,
myositis

Pulm symptomscough, hemoptysis, shortness of breath with
exertion

Neurobells palsy, seizures

Skin lesionsplaques, subcutaneous nodules, erythema nodosum

Cardiacarrhythmias, CHF

Lympthadenopathy

Ophthalmologicuveitis, or conjunctivitis

37. +
Sarcoidosis

Diagnosis

CXR


Stage 1hilar adenopathy

Stage 2Hilar adenopathy and parenchymal involvement

Stage 3parenchymal involvement without adenopathy


Stage 0no findings
Stage 4pulmonary fibrosis
Lab studies

Leukocytosis, elevated ESR or serum ACE, hypercalcemia or
hyperphosphatemia, elevated CK and CK-MB with cardiac
involvement

Gallium 67used to detect extrapulmonary sarcoidosis

Biopsy of involved organ is most useful for diagnosis

38. +
Sarcoidosis

Management

Cardiac monitoring

Consider steroids or cytotoxic medications

Lung transplantation for patients with severe refractory disease

39. +
Thromboembolic Disease

DVT

PE

40. +
DVT

Risk factors

Previous thrombosis

Vascular endothelial damage


Trauma, sugery (especially ortho), smoking
Hypercoagulability


Factor V Leiden (most common hereditary hypercoagulability

Antithrombin III deficiency


Protein C or S deficiency
Oral contraceptives or 3rd trimester pregnancy
Immobilization or low cardiac output

Long periods of sitting, CHF

41. +
DVT

Signs and Symptoms

Pain, warmth and edema

Discoloration of affected extremity

Palpable cord of a thrombosed vein

42. +
DVT

Diagnosis

CT angiography

Doppler ultrasonography


Limitationsoperator dependent, cannot distinguish between old
and new clot, not accurate in detecting DVT in the pelvis or the
small vessels of the calf
Management

Anticoagulationunfractionated low-molecular weight heparin or
warfarin therapy

Filter placement for patients with failure of anticoagulation or
contraindication to anticoagulation

43. +
Pulmonary Embolus

Risk factor are the same as for DVT 60% of patients with a
DVT have a PE

Symptoms and signs

Sudden-onset dyspnea, tachypnea, tachycardia, pleuritic pain,
hemoptysis, syncope, cough, and wheeze

44. +
PE diagnosis

ECG


Nonspecific ST-T wave changes and/or sinus tach are most common, S1Q3T3,
precordial flipped T waves
CXR



Findings are abnormal but nonspecific, pleural effusion, elevated hemidiaphragm
secondary to atelectasis and noninfectious infiltrates
Westermark signabrupt cut-off of vascular markings
Hamptom humppleural based wedge-shaped infarct

CT pulm angiography

VQ scanuseful in severe contrast allergies

A normal scan is sufficient to exclude PE in patient with low pretest probability

Echomay reveal evidence of right heart strain

Pulmonary angiographythe gold standard for diagnosing PE (used
infrequently because of noninvasive CT scans

45. +
PE management

Supplemental O2

Hemodynamic support

Anticoagulation

Thrombolytic

Indicated in patients with associated hemodynamic instability

Surgical Embolectomy

IVC filter for anticoagulation failure or contraindication

46. +
Pulmonary Infections

Pneumonia



Bacterial
viral
Tuberculosis

47. +
Bacterial Pneumonia

Etiology

Typical Pneumonia


S. pneumoniae, H. influenzae, and Staph (S. Pneumo most
common)
Atypical Pneumonia

Influenza virus, mycoplasma, chlamydia, legionella, and
adenovirus

IV drug usersS. aureus

Alcoholism, diabetes, and COPDK, Pneumoniae

AsthmaticsH. Flu

Hospital acquired pneumoniapseudomonas aeruginosa

48. +
Bacterial Pneumonia

Symptoms and signs

Chest pain

Productive cough

Klebsiellacurrant jelly

S. Pneumoniaebloody or rusty colored

Aspirationfoul-smelling sputum

Chlamydiastaccato cough

Rigorsparticularly associated with S. Pneumonia

Diarrhea and GI upset with Legionella

Bullous myringitis with Mycoplasma pneumoniae

Pleural rubs

49. +
Bacterial Pneumonia

DiagnosisChest radiography

Bilateral diffuse infiltrates consistent with atypical infections (M.
Pneumoniae, P. Carinii, C. Psittaci)

Abscess and bulging lung fissures are indicative of infections
caused by Klebsiella and S. aureus

Pleural effusions and empyema associated with cavitary lesions are
seen with s. aureus and M. tuberculosis

Upper lung fieldsK. Pneumoniae

Lower lung fieldsL. Pneumoniae

Miliary patternM. Tuberculosis

50. +
Bacterial Pneumonia

Laboratory studies

Hyponatremia and hypophosphatemia associated with L.
Pneumophila

Sputum samples for gram stain and culture are accurate about 50%
of the time

Adequate sputum contains <10 epithelial cells, >25 WBC per low
power field and remain uncontaminated from oral flora

Mycoplasma and Chlamydia immunoglobulin M antibodies a
rise in antibody titer of 1:128 confirms the diagnosis

51. +
Bacterial Pneumonia

Management

Community-acquired pneumonia



Pneumonia severity index score helps determine risk
Admit if total score >90 points and consider ICU for >130
Hospital-acquired pneumonia



Double-drug coverage for Pseudomonas
Optimal combinations include cefipime plus levofloxacin,
aztreonam, meropenem, or aminoglycoside
Aspiration pneumonia

Intubation should be considered in any patient who is unable to
protect airway, add anaerobic coverage

52. +
Types of Bacterial Pneumonia

Bordetella Pertussis (whopping cough)


Summer and fall months, neither active disease nor vaccination
provides lifelong immunity
Symptoms and signs3 stages, each lasting about 2 weeks

Catarrhal


Paroxysmal


Most infectious during this time, symptoms indistinguishable from
a URI
Coughing episodes followed by an inspiratory “whoop” , posttussive exhaustion and emesis
Convalescent

Chronic cough that can last several months

Complications include mucous plug, secondary bacterial infection,
ruptured diaphragm, hernia, and rectal prolapse

53. +
Pertussis

Diagnosis



Degree of lymphocytosis correlates with severity of disease
Definitive diagnosis is made via nasopharyngeal culture
Treatment

Erythromycin x14 days

Consider prophylaxis with erythromycin for close contacs

Consider hospitalization for infants <6 months, premature infants,
and those with significant comorbitites

54. +
Mycoplasma Pneumonia

Most common atypical

14-day incubation period

More common in young adults

CXR may show interstitial pattern or patchy infiltrate

Treat with macrolide antibiotic

Associations




Bullous myringitis
Meningitis and encephalitis
Erythema multiforme
Guillain-Barre

55. +
Chlamydia Pneumonia

Obligate intracellular parasite

Infants





Acquired at birth
50% conjunctivitis
Tachypnea
May be afebrile
CXR shows hyperinflation and diffuse infiltrates

Common in young adults complaining of hoarseness, cough, and
persistent malaise

Staccato cough

Treat with macrolide

56. +
Legionella Pneumonia

Airborne and associated with water sources

Classically associated with recent air travel

No person to person transmission

Symtpoms and signs


Pleuritic chest pain, relative bradycardia, GI symtpoms
Diagnosis

Labs may reveal hyponatremia and hypophosphatemia

Chest x-ray may show alveloar infiltrates or consolidation that my
progress to hilar adenopathy and pleural effusion

Treat with erythromycin for 3 weeks

57. +
Tuberculosis

Leading cause of death worldwide

Humans are sole reservoir

TB can remain dormant for years in granulomas

Risk factors

Immunocompromised (HIV, malignancy, DM, extremes of age)

Close contacts or occupational exposure

Medically underserved, low-income populations

58. +
TB symptoms and signs

Primary TB

Only 10% of exposed individuals develop primary TB

Constitutional symptoms

Coughmost common symptoms of pulmonary TB

Initially nonproductive or nonspecific sputum

Hemoptysis may be presenting complaint

Pleuritic chest pain

Night sweats

“classic” presentation is uncommon

59. +
TB

Postprimary TB (reactivation TB)

Lifetime risk in immunocompetent individual is 10% to 15%

In HIV-positive patients

37% with disease in 6 months

10% incidence of disease per year

Signs and symptoms similar to primary TB

60. +
TB extrapulmonary

Lymphadenitis (scrofula)


Pleural effusion


Pott’s disease (spinal)spinal cord injury possible, lumbar infection may lead to
psoas abscess
acute disseminated


Small and unilateral, diagnosis through pleurocentesis
Bone and joint infection


Most common EPTB, enlarging, painless, erythematous firm mass near cervical
nodes, do NOT I and D
Generalized systemic illness, typically in elderly and HIV patients, fever, weight
loss, anorexia, weakness, SIADH is common, often associated with meningitis
CNS


6% of cases, peak in newborn to 4 years, SIADH, tuberculosis meningitis
CSF analysislowest glucose CSF levels of any meningitis

61. +
TB diagnosis

TB skin testingread 48-72 hours later, induration not
erythema

15mm in low-risk, immunocompetent patients

10mm in high-risk immunocopetent patients

5mm in HIV, Close contacts infectious TB, abnormal CXR,
immunocompromised from steroids

62. +
TB medical therapy

Latent TBinfections without active disease,
chemoprophylaxis with isoniazid for 9 months

Active TBtreated for 6 months, 4 drugs until resistance
pattern determined, after 2 months may discontinue
pyrazinamide if TB isolates do not demonstrate resistance

Extrapulmonary TB->treat for 6 months

CNS infection (tuberculous meningitis) is the exception, requires 912 months of treatment

Consider steroids for CNS and pericardial TB

63. +
Treatment of TBdrugs

First line agents

Isoniazid (INH)



8% resistance rate
Prevent INH-related seizures: supplement with pyridoxine (B6)
Rifampin



Orange discoloration of bodily fluids
Oral contraception failure
Pyrazinamide (PZA)


Hepatotoxicity, polyarthralgias
Ethambutol (ETH)

Prevents emergence of RIF resistance

Retrobulbar neuritisdecreased visual acuity or red/green color
blindness

64. +
Treatment cont.

Noncompliant patients


Court-ordered directly observed therapy (DOT)


Uncooperative and potentially infectious patients may be compelled
to comply
Incarceration as last resort
In pregnancy

INH, RIF, ETH cross placenta and are safe

65. +
Viral Pneumonia

Influenza

Varicella

Cytomegalovirus

hantavirus

66. +
influenza

Often associated with bacterial superinfection (s. aureus)

Diagnosis: nasopharyngeal swab culture for influenza aid
diagnosis

CXR shows diffuse bilateral infiltrates

67. +
Varicella

Symptoms and signs: pneumonia may present with chest pain
and hemoptysis preceded by a rash

More severe in adults

Managementmandates admission for treatment with
acyclovir

68. +
cytomegalovirus

Most common in solid organ transplant and bone marrow
transplant recipients

Often presents simultaneously with pneumocystis pneumonia

Management


IV ganciclovir or foscarnet plus immunoglobulin therapy
CXR

Bilateral interstitial pattern

69. +
Hantavirus

Aerosolized contaminated material from rodent feces or urine

Southwest US

Symptoms and signsflu-like symtpoms that progress to
respiratory distress and shock

DiagnosisCXR reveals bilateral infiltrates

70. +
Fungal Pneumonia

Histoplasma capsulatum, blastomyces dermatitides and
coccidioides present in the soil in various geographic areas of
the US

Histoplasma capsulatum in the mississippi and Ohio River valleys

Coccidioides immitis in desert areas of the Southwest

Symptoms and signs vary from acute or chronic pneumoina to
asymptomatic granulomas on CXR

Diagnosishilar adenopathy