Radiology In The Intensive Care Unit

Radiology in the Intensive Care Unit William William Herring, Herring, M.D. M.D. Department Department of of Radiology Radiology Albert Albert Einstein Einstein Medical Medical Center Center Philadelphia, Philadelphia, PA PA

Atelectasis Types Types

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Lobar

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Subsegmental, discoid, plate-like

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Compression-as in pleural effusion

Atelectasis Lobar Lobar

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Area of increased density with shift towards that side ■

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Predictable x-ray patterns Especially likely with mucous plug or malplaced ETT ■

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Fissures, heart or trachea, diaphragm

Usually involves left lung and right upper lobe

May respond to respiratory PT or bronch

Atelectasis Subsegmental Subsegmental

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Hypoventilation/surfactant deactivation Horizontal, linear densities at bases Asymptomatic ■

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May herald pneumonia

Responds to deep breathing Disappears in several days

Pleural Effusions X-ray X-ray Appearance Appearance

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Subpulmonic at first

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Need 250cc to blunt angle

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Meniscus appearance

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Straight line indicates presence of PTX

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Free-flowing on decub

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Ultrasound for guidance

Pleural Effusion Causes Causes

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CHF-mostly right sided or bilateral

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Post-operative irritation

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Pulmonary thromboembolic disease

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Para-pneumonic effusion

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Trauma-blood

Pneumonia ●

Consolidation of lung with air bronchograms

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No shift of heart or mediastinal structures

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Frequently staph or gram negative

Aspiration

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Fleeting, patchy infiltrates-very common in ICU Usually at bases, mostly on right

Aspiration

Appearance Appearance Based Based on on Cause Cause

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If bland, disappears within day or two If HCl, chemical pneumonitis lasts for days If infected with gram negatives, pneumonia ensues

Pneumothorax ●

Must identify visceral pleural white line to dx

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Careful search required

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Small require upright film

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Deep sulcus sign

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Always get x-ray after failed CVC attempt

Pulmonary Embolism Without Without Infarction Infarction

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More common than suspected Chest x-ray most often normal in appearance Discoid atelectasis, elevation of hemidiaphragm Lung scan for screen

Pulmonary Embolism With With Infarction Infarction

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Usually multiple

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Usually at bases

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Pleural effusion, infiltrate

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“Hampton’s Hump” is very unusual

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Clear with scarring; “melting sign”

Congestive Heart Failure X-ray X-ray Findings Findings

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Pleural effusions-> on right or bilateral

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Fluid in fissures-thicker than a sharpened pencil

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Kerly B lines-perilymphatic, interstitial fluid

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Peribronchial cuffing

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NOT cardiomegaly

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NOT “pulmonary vasculature congestion”

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NOT cephalization

ARDS Causes Causes

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Shock

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DIC

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CNS injury

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Sepsis

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Drug overdose

ARDS

X-ray X-ray Findings Findings ●

Diffuse alveolar infiltrates hours after insult

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No fluid in fissures or pleural effusions

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Characteristically lasts days-weeks

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May become interstitial ■

Fibrosis or disappears

Iatrogenic Complications

Central Venous Catheters Normal Normal Anatomy Anatomy

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Subclavian joins brachiocephalic vein behind medial end of clavicle Catheter should reach this point before descending Catheter should descend lateral to spine and tip should be in either brachiocephalic v. or SVC

Central Venous Catheters Malpositioned Malpositioned

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Most often malpositioned in RA or internal jugular

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Sometimes contralateral subclavian

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Occasionally outside blood vessel ■

Look for sharp bends in catheter

Central Venous Catheters Two Two or or more more attempts attempts

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Should initial placement fail, get a chest x-ray before trying other side to avoid bilateral pneumothoraces

Central Venous Catheters Potential Potential Causes Causes of of Fatalities Fatalities

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Air embolism

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Pneumothorax

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Hemothorax

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Cardiac perforation

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Sepsis

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Venous perforation

Swan-Ganz Catheters Normal Normal Anatomy Anatomy

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Ideally located tip lies within Right or Left pulmonary artery

Swan-Ganz Catheters Complications Complications

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Most common significant complication is pulmonary infarction ■

From occlusion by catheter

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From embolization off of catheter

Uncommon ■

Cardiac arrhythmia

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Pulmonary artery perforation

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Intracardiac knotting

Endotracheal Tube Normal Normal Anatomy Anatomy

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Tip should lie between clavicles and carina

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Carina usually at level of T4

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Tip should be at least 5cm above carina

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Tip may change by 2cm with flex/extension

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Balloon should never occupy more than half of lumen

Endotracheal Tube Complications Complications

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Most common malposition: tip in right mainstem bronchus ■

Atelectasis

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R sided tension pneumothorax

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Tube in pharynx: aspiration

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Sinusitus 2° nasal mucosa edema

Tracheostomy Normal Normal anatomy anatomy

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Tip at T3

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Tip half-way between stoma and carina

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Tip placement not affected by flex/extension

Tracheostomy Complications Complications

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Immediately after ■

Subcutaneous emphysema

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Pneumomediastinum

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Pneumothorax

Cuff should not be >1 1/2 X diameter of lumen Tracheal stenosis

Tracheostomy Tracheal Tracheal Stenosis Stenosis ●

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Most common late-occurring complication of tracheostomy tube May occur at stoma, at level of cuff or at tip of tube Most common at stoma Very common; in fact, it may occur in every patient with prolonged intubation Trachea should narrow to 4mm for stridor to occur

Pleural Drainage Tubes

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Ideal position is anterosuperior for PTX and posteroinferior for effusion Usually work well no matter where positioned Look for holes outside of chest

Nasogastric Tube Complications Complications

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Perforation usually involves cervical esophagus

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Tube can also perforate stomach

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Indwelling tube leads to GE reflux which may cause esophagitis and stricture

Nasogastric Tube Complications Complications

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NG tubes may be inserted in trachea leading to ■

Infection

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Pneumothorax

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Pleural effusion

Usually right mainstem bronchus

Pacemakers Normal Normal anatomy anatomy

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Catheter should have gentle curves

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Tip positioned at apex of R ventricle

Pacemaker Complications Complications

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Leads can fracture Leads can perforate heart producing cardiac tamponade Look for sharp bends in leads indicating perforation of blood vessel Leads may be ectopically placed, e.g. hepatic vein Pacemaker battery may migrate subcutaneously