Pulmonary Edema Pathophysiological Considerations Manifestations on Chest Radiography

Pulmonary Pulmonary EdemaEdema

Pathophysiological ConsiderationsPathophysiological Considerations Manifestations on Chest Radiography Manifestations on Chest Radiography

Kathryn Glassberg MS4Kathryn Glassberg MS4

February 2006February 2006

Pulmonary Edema: Pulmonary Edema: OverviewOverview

Pathophysiology : Edema as an end Pathophysiology : Edema as an end result of a multitude of diverse insults result of a multitude of diverse insults (not just heart failure vs. ARDS!) (not just heart failure vs. ARDS!)

Physiologic approach for radiologic Physiologic approach for radiologic evaluation of edemaevaluation of edema Hydrostatic edemaHydrostatic edema Permeability edema +/- diffuse alveolar Permeability edema +/- diffuse alveolar

damagedamage Mixed permeability and hydrostatic edemaMixed permeability and hydrostatic edema

Pulmonary EdemaPulmonary Edema

Edema occurs when physiologic resorption Edema occurs when physiologic resorption of fluid via lymphatics is overwhelmed of fluid via lymphatics is overwhelmed

Causes usually divided into “hydrostatic” Causes usually divided into “hydrostatic” and “increased capillary permeability”, but and “increased capillary permeability”, but both mechanisms can occur in the same both mechanisms can occur in the same patient!patient!

Chest radiography, when combined with Chest radiography, when combined with clinical data, helps distinguish pathologic clinical data, helps distinguish pathologic cause in vast majority of casescause in vast majority of cases

Causes of Pulmonary Causes of Pulmonary EdemaEdema11

HydrostaticHydrostatic

Cardiac: Left heart failureCardiac: Left heart failure NoncardiacNoncardiacIncreased transmural

capillary pressureIncreased transmural

capillary pressureLymphatic block: lymphangitis, carcinomitosis, lymphangiectasia

Lymphatic block: lymphangitis, carcinomitosis, lymphangiectasia

Increased intracapillary pressure:neurogenic, hyperperfusion (high altitude,

postembolic, post transplant)

Increased intracapillary pressure:neurogenic, hyperperfusion (high altitude,

postembolic, post transplant)

Lowered extracapillary pressure: reexpansion edema,

postglottic spasm

Lowered extracapillary pressure: reexpansion edema,

postglottic spasm

Oncotic: nutritional, near-drowningOncotic: nutritional, near-drowning

Combined hemodynamic/oncotic: renal failure, overhydration

Combined hemodynamic/oncotic: renal failure, overhydration

Causes of Pulmonary Causes of Pulmonary EdemaEdema11

Increased capillary permeability

Increased capillary permeability

InjuryInjuryNoninjury:

Allergic, endocrineNoninjury:

Allergic, endocrine

Extracapillary (alveolar insult): Inhalation, aspiration, infection

Extracapillary (alveolar insult): Inhalation, aspiration, infection

IntracapillaryIntracapillary

“Trauma”: sepsis, hypotension,

Pancreatitis, DIC

“Trauma”: sepsis, hypotension,

Pancreatitis, DIC

Embolism: fat, air, amniotic fluid

Embolism: fat, air, amniotic fluid

Pathophysiology Pathophysiology overviewoverview22

Normally, excess Normally, excess hydrostatic hydrostatic transudate from transudate from pulmonary pulmonary capillaries is capillaries is filtered into filtered into peribronchovasculperibronchovascular lymphatics and ar lymphatics and removedremoved

Pathophysiology Pathophysiology overviewoverview22

In hydrostatic edema, In hydrostatic edema, transudatetransudate accumulates in the accumulates in the interstitum initially, interstitum initially, only entering alveoli in only entering alveoli in severe cases severe cases

In permeability edema In permeability edema associated with diffuse associated with diffuse alveolar damage alveolar damage (DAD), (DAD), exudateexudate fills fills the interstitum and the interstitum and the alveolithe alveoli

Hydrostatic EdemaHydrostatic Edema33

The lungs can accommodate The lungs can accommodate increases in fluid: the lymphatic increases in fluid: the lymphatic flow can increase 3-10x before flow can increase 3-10x before edema developsedema develops

Higher hydrostatic pressures Higher hydrostatic pressures force fluid through endothelial force fluid through endothelial cell pores, but the tighter cell pores, but the tighter junctions of epithelial cells junctions of epithelial cells prevent fluid from entering prevent fluid from entering alveoli until pulmonary capillary alveoli until pulmonary capillary pressures reach ~ 40 mm Hg, pressures reach ~ 40 mm Hg, causing stress failurecausing stress failure

Hydrostatic Edema: Hydrostatic Edema: radiologic manifestationsradiologic manifestations33

Earliest sign: vascular indistinctnessEarliest sign: vascular indistinctness Bronchial wall thickening/peribronchial Bronchial wall thickening/peribronchial

cuffingcuffing Septal lines: Kerley A, B, CSeptal lines: Kerley A, B, C Thickened fissuresThickened fissures Severe edema: dependent ground glass Severe edema: dependent ground glass

opacities reflecting alveolar involvementopacities reflecting alveolar involvement Often associated with bilateral Often associated with bilateral

transudative pleural effusionstransudative pleural effusions

Hydrostatic Edema: Hydrostatic Edema: radiologic manifestationsradiologic manifestations33

““Cephalization” or “inversion” not Cephalization” or “inversion” not specific for edemaspecific for edema Reflects chronic pulmonary venous changes Reflects chronic pulmonary venous changes

in patients with left-sided heart failurein patients with left-sided heart failure Vascular pedicle widthVascular pedicle width

patients with volume overload often have patients with volume overload often have widened vascular pedicles when compared widened vascular pedicles when compared to previous studiesto previous studies

However, patients can certainly have However, patients can certainly have hydrostatic edema despite a narrow hydrostatic edema despite a narrow pedicle, thus this sign can be misleadingpedicle, thus this sign can be misleading

Vascular indistinctnessVascular indistinctnessNormal

Edema

Images courtesy of Dr. Marc Gosselin

Vascular IndistinctnessVascular IndistinctnessNormal

Edema


Peribronchial cuffingPeribronchial cuffing

Images shown Images shown are pre- and are pre- and post-treatment post-treatment for hydrostatic for hydrostatic edemaedema

Arrowheads Arrowheads point to Kerley A point to Kerley A lineslines

Septal LinesSeptal Lines33

The presence of septal lines reflects fluid The presence of septal lines reflects fluid accumulation between the lung lobulesaccumulation between the lung lobules

Kerley linesKerley lines A: long, diagonal, centralA: long, diagonal, central B: short, horizontal, extend to lateral pleural B: short, horizontal, extend to lateral pleural

surfacessurfaces C: reticular pattern of ~ 1 cm polygons C: reticular pattern of ~ 1 cm polygons

representing septal lines viewed on end representing septal lines viewed on end (I’ve heard Dr. Kerley is the only one who (I’ve heard Dr. Kerley is the only one who has ever really seen these…)has ever really seen these…)

Septal LinesSeptal Lines

Septal lines Septal lines in a patient in a patient with cardiac with cardiac failurefailure


Lateral view of Lateral view of same patient– same patient– note fluid in note fluid in both fissuresboth fissures


All three All three Kerleys Kerleys claim to be claim to be present; present; can you can you find them?find them?


Even in you Even in you can’t name can’t name the lines, you the lines, you can see that can see that this patient this patient has severe has severe hydrostatic hydrostatic edema in edema in need of need of treatment!treatment!

A

B

C?

Evolving hydrostatic Evolving hydrostatic edemaedema44

33 year-old 33 year-old with AML with AML admitted for admitted for renal failure renal failure and fluid and fluid overloadoverload


Arrows indicate Arrows indicate peri-bronchial peri-bronchial cuffingcuffing

Note increasing Note increasing size of azygous size of azygous veinvein


Arrowheads Arrowheads indicate septal indicate septal lineslines

Note ground-Note ground-glass, glass, indicating indicating alveolar edemaalveolar edema

Permeability EdemaPermeability Edema

multiple insults can cause increased multiple insults can cause increased pulmonary vessel permeability pulmonary vessel permeability resulting in leakage of fluid AND resulting in leakage of fluid AND proteinprotein

In its most severe form, the disease In its most severe form, the disease is a combination of vessel is a combination of vessel permeability and DAD, leading to the permeability and DAD, leading to the acute respiratory distress syndrome acute respiratory distress syndrome (ARDS)(ARDS)

ARDS pathologyARDS pathology33

Acutely, exudative Acutely, exudative edema in the edema in the alveoli causes alveoli causes hyaline membrane hyaline membrane formationformation

Type II epithelial Type II epithelial cells then cells then proliferate and, proliferate and, usually, fibrosis usually, fibrosis occursoccurs

ARDS: Radiologic ARDS: Radiologic manifestationsmanifestations33

Patchy, diffuse ground glass opacitiesPatchy, diffuse ground glass opacities Pattern of opacification does not change Pattern of opacification does not change

with position change, as the exudates are with position change, as the exudates are trapped in alveolitrapped in alveoli

Septal lines, peribronchial cuffing, and Septal lines, peribronchial cuffing, and thick fissures are usually ABSENTthick fissures are usually ABSENT

In severe cases, air bronchograms can be In severe cases, air bronchograms can be seenseen

Good rule of thumb: presence of ET tube!Good rule of thumb: presence of ET tube!

ARDS: Radiologic ARDS: Radiologic manifestationsmanifestations33

Caution: While a normal sized heart Caution: While a normal sized heart and narrow vascular pedicle are and narrow vascular pedicle are helpful signs, neither is specific for helpful signs, neither is specific for injury edemainjury edema

ARDS ARDS

Patchy Patchy diffuse diffuse ground glassground glass

Air Air bronchogrambronchogramss

ET tubeET tube

Permeability Edema Permeability Edema without DADwithout DAD33

Seen in IL-2 therapy for metastatic Seen in IL-2 therapy for metastatic disease, hantavirus pulmonary disease, hantavirus pulmonary syndromesyndrome

Severe capillary permeability Severe capillary permeability without alveolar involvementwithout alveolar involvement

Radiographically, resembles Radiographically, resembles hydrostatic edema (septal lines, hydrostatic edema (septal lines, peribronchial cuffing) because peribronchial cuffing) because alveolar epithelium remains intactalveolar epithelium remains intact

Mixed hydrostatic and Mixed hydrostatic and permeability edemapermeability edema

High-altitude pulmonary edemaHigh-altitude pulmonary edema Neurogenic edemaNeurogenic edema Reexpansion and post-obstructiveReexpansion and post-obstructive

High-altitude pulmonary High-altitude pulmonary edema (HAPE)edema (HAPE)33

Hypoxia causes non-uniform Hypoxia causes non-uniform pulmonary vasoconstriction, leaving pulmonary vasoconstriction, leaving other lung units over-perfused and other lung units over-perfused and predisposed to edemapredisposed to edema

Higher pressures can result in some Higher pressures can result in some capillary damage and stress failurecapillary damage and stress failure

High-altitude pulmonary High-altitude pulmonary edemaedema33

Radiographs show Radiographs show patchy ground patchy ground glass with a glass with a central distribution central distribution favoring favoring peribronchial peribronchial cuffing and cuffing and vascular vascular indistinctness over indistinctness over septal linesseptal lines

Neurogenic EdemaNeurogenic Edema33

Pathophysiology similar to HAPE– Pathophysiology similar to HAPE– neural mechanisms result in non-neural mechanisms result in non-uniform vasoconstrictionuniform vasoconstriction

High protein content of fluid High protein content of fluid indicates capillary leakage involved indicates capillary leakage involved as wellas well


Classically, neurogenic edema has Classically, neurogenic edema has an upper lobe predominance; an upper lobe predominance; however, it can present with any however, it can present with any patternpattern

Often clears rapidly, arguing for Often clears rapidly, arguing for intact alveoliintact alveoli


54 year-old 54 year-old woman with woman with intracranial intracranial hemorrhagehemorrhage

Note upper Note upper lobe lobe predominancepredominance

Reexpansion and Reexpansion and Postobstructive EdemaPostobstructive Edema33

Both occur in setting of high negative Both occur in setting of high negative pleural pressurepleural pressure

Reexpansion: usually seen as localized Reexpansion: usually seen as localized lung injury, with alveolar filling and lung injury, with alveolar filling and exudative fluid, arguing for increased exudative fluid, arguing for increased permeability as a causepermeability as a cause

Postobstructive: pattern usually Postobstructive: pattern usually hydrostatic, secondary to increased hydrostatic, secondary to increased central blood volume caused by the relief central blood volume caused by the relief of obstructionof obstruction

Reexpansion EdemaReexpansion Edema44

Right pneumothorax One-hour post chest-tube placement

Postobstructive EdemaPostobstructive Edema44

Postextubation Laryngospasm: note Postextubation Laryngospasm: note central distribution and central distribution and peribronchial cuffing.peribronchial cuffing.

ConclusionsConclusions Hydrostatic Edema is characterized by Hydrostatic Edema is characterized by

Vascular indistinctnessVascular indistinctness Peribronchial cuffingPeribronchial cuffing Septal lines/fissure thickeningSeptal lines/fissure thickening

Permeability Edema with DAD (ARDS) is Permeability Edema with DAD (ARDS) is characterized bycharacterized by Diffuse, patchy ground glass opacitiesDiffuse, patchy ground glass opacities Air bronchogramsAir bronchograms

Overlap is seen in pathophysiology, thus Overlap is seen in pathophysiology, thus can be reflected in the radiographcan be reflected in the radiograph

Summary TableSummary Table11

HydrostaticHydrostatic Permeability Permeability with DADwith DAD

Heart sizeHeart size Often enlargedOften enlarged Usually not Usually not enlarged enlarged

Septal LinesSeptal Lines CommonCommon AbsentAbsent

Peribronchial Peribronchial cuffscuffs

CommonCommon Not commonNot common

Air Air bronchogramsbronchograms

Not commonNot common Very commonVery common

Regional Regional distributiondistribution

Even or centralEven or central Patchy or Patchy or peripheralperipheral

Hydrostatic and Hydrostatic and Permeability EdemaPermeability Edema


““The condition of the capillary The condition of the capillary endothelium and that of the endothelium and that of the

alveolar epithelium are the main alveolar epithelium are the main determinants”determinants”33

ReferencesReferences11Milne ENC and Massimo P. Milne ENC and Massimo P. Reading the Chest Reading the Chest

Radiograph: A Physiologic Approach.Radiograph: A Physiologic Approach. Mosby, Mosby, 1993.1993.

22Ware LB and Matthay MA. Acute pulmonary Ware LB and Matthay MA. Acute pulmonary edema. edema. The New England Journal of Medicine. The New England Journal of Medicine. 2005; 353: 2788-96. 2005; 353: 2788-96.

33Ketai LH and Godwin JD. A new view of pulmonary Ketai LH and Godwin JD. A new view of pulmonary edema and acute respiratory distress syndrome. edema and acute respiratory distress syndrome. Journal of Thoracic ImagingJournal of Thoracic Imaging. 1998; 13: 147-171.. 1998; 13: 147-171.

44Gluecker T. Capasso P. Schnyder P. Gudinchet F. Gluecker T. Capasso P. Schnyder P. Gudinchet F. Schaller MD. Revelly JP. Chiolero R. Vock P. Schaller MD. Revelly JP. Chiolero R. Vock P. Wicky S. Wicky S. Clinical and radiologic features of pulmonary edema. Radiographics. Radiographics. 19(6):1507-31; 19(6):1507-31; discussion 1532-3, 1999 Nov-Dec. discussion 1532-3, 1999 Nov-Dec.

ReferencesReferences

Images taken from: Images taken from: myweb.lsbu.ac.ukmyweb.lsbu.ac.uk/ ~/ ~dirt/museum/p6-71.htmldirt/museum/p6-71.html www.bcm.eduwww.bcm.edu/.../cases/ pediatric/text/7a-desc.htm/.../cases/ pediatric/text/7a-desc.htm http://www.hcoa.org/hcoacme/chf-cme/chf00030.htmhttp://www.hcoa.org/hcoacme/chf-cme/chf00030.htm http://www-medlib.med.utah.edu/WebPath/LUNGHTML/LUNG131.htmlhttp://www-medlib.med.utah.edu/WebPath/LUNGHTML/LUNG131.html http://www-medlib.med.utah.edu/WebPath/LUNGHTML/LUNG133.htmlhttp://www-medlib.med.utah.edu/WebPath/LUNGHTML/LUNG133.html http://www.lumen.luc.edu/lumen/MedEd/MEDICINE/PULMONAR/CXR/atlas/http://www.lumen.luc.edu/lumen/MedEd/MEDICINE/PULMONAR/CXR/atlas/

images/310a1.jpgimages/310a1.jpg www.high-altitude-medicine.com/ AMS-medical.html www.high-altitude-medicine.com/ AMS-medical.html Sherman SC. Reexpansion pulmonary edema: a case report and review of the Sherman SC. Reexpansion pulmonary edema: a case report and review of the

current literature. current literature. Journal of Emergency Medicine.Journal of Emergency Medicine. Jan 2003; 24(1): 23-7. Jan 2003; 24(1): 23-7.

Thanks to Dr. Marc Gosselin for Thanks to Dr. Marc Gosselin for images, insightsimages, insights

Pulmonary Edema Pathophysiological Considerations Manifestations on Chest Radiography

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