Download Tubes & Lines: Radiographic Evaluation of the Placement of

Tubes & Lines
Radiographic Evaluation of the Placement of
Monitoring and Support Devices
Tula Top
February 20, 2004
Central Venous Catheters
Central Venous Catheters
Purpose
Central venous catheters, also known as central venous pressure (CVP)
lines, are used to monitor central venous pressure in the ICU and also
allow for intravenous fluid or medication administration.
Central Venous Catheters
Access and Placement
CVP lines are typically inserted through
the internal jugular, subclavian, or
femoral veins, and offer more consistent
venous blood flow than more
peripherally inserted catheters, which
may be subject to compression via
vasoconstriction during times of
cardiovascular collapse. The CVP line
should ideally be positioned central to
the venous valves at the origin of the
superior vena cava. The SVC is formed
by the junction of the right and left
brachiocephalic veins and lies to the
right of midline at the level of the first
intercostal space.
The following radiograph demonstrates
a CVP line in the proper position.
Central Venous Catheters
Central Venous Catheters
What’s the finding in the following chest radiograph?
Click for a hint.
The CVP line is
in the left
Subclavian
Artery.
Click for another hint.
We expect the
line to end up
here…
The CVP line is
in the left
Subclavian
Artery.
Click for another hint.
We expect the
line to end up
here…
The CVP line is
in the left
Subclavian
Artery.
Then, where
is the tip
located?
Click for the answer.
Central Venous Catheters
Answer:
The tip is in Descending Thoracic Aorta.
When the line extends above the clavicle, it is very likely that it lies in
the subclavian artery. The subclavian vein normally lies behind the
clavicle.
Differential Location (if in vein):
A left-sided SVC is a normal anatomic variant in 0.3% of individuals, of
whom some two-thirds will also have a right-sided SVC. A large
proportion of these individuals also will have the left BCV connecting to
both the right and left SVCs. When the SVC is duplicated, the vessels
typically are relatively smaller in caliber than those in patients with single
SVCs. The left SVC drains through the oblique vein of the left atrium,
the great cardiac vein, and the coronary sinus into the right atrium.
Biffi M., et al. “Left superior vena cava persistence in patients undergoing pacemaker or cardioverterdefibrillator implantation: a 10-year experience.” Chest. 120(1):139-44, 2001 Jul.
Which Line Did you Put in?
The Right or Left Subclavian?
Which Line Did you Put in?
The Right or Left Subclavian?
Right Subclavian Artery
Left Subclavian Vein
Central Venous Catheters
What’s the finding in the following chest radiograph?
Click for a hint.
Is the CVP line in
the right place?
Click for another hint.
Yes, it is. But
what—and
where—is this
lucency?
Is the CVP line in
the right place?
Click for the answer.
Central Venous Catheters
Complications
Air embolization is a potentially fatal complication of venipuncture and
line placement and may be detected on CXR or CT with concomitant
intravenous contrast injection.
Central Venous Catheters
Complications
Catheters placed in the left brachiocephalic vein should demonstrate an
anterior curve on the lateral chest radiograph as the left BCV courses
anteriorly to join the right BCV. A posterior projection of the catheter tip
suggests placement into the azygos vein, which joins the SCV
posteriorly prior to entering the pericardium. Such malpositioning may
be missed if evaluated solely by a PA radiograph. Suspect placement of
the catheter tip merits orthogonal views to confirm its location.
Central Venous Catheters
Complications
The vasculature in close proximity to the heart offers a number of aberrant
routes for an inserted CVP line to follow. Among the most common are
the:

Internal jugular vein

Right atrium (with risk of perforation or dysrhythmias if placed near the
tricuspid valve)

Right ventricle

Opposite subclavian vein

Corresponding artery

Numerous extrathoracic locations (with potential of ectopically infusing
toxic substances in the vicinity of the liver or heart instead of into the
central venous system where rapid dilution can occur; look for
widening and opacification of the mediastinum or pleural space due to
rapid accumulation of fluid.)

Venous perforation may also occur if a catheter tip abutting the lateral
wall of the SVC places excessive focal pressure on the wall.
Central Venous Catheters
Complications


Every chest radiograph that features a CVP catheter should be evaluated
carefully for pneumothorax, which occurs with 6% of line placements and
can manifest several days after the procedure. Moreover, there is an
increased potential for bilateral PTX given that a PTX on one side may
have gone undetected following an initial failed attempt at line insertion
before success was finally achieved on the other side.
Catheter embolization can occur as a result of laceration of the catheter
by the insertion needle, catheter fracture at a point of stress, or
detachment of the catheter from its hub. The freed apparatus may lodge
in the SVC, inferior vena cava, right heart, or pulmonary artery, causing
thrombosis, infection, or perforation.
Central Venous Catheters
Complications



The catheter tip may serve as a nidus for clot formation, impairing its
ability to measure central venous pressure accurately or to deliver fluids
to the venous system.
Extension of the clot may result in venous thrombus or pulmonary
embolus.
The “pinch-off” syndrome refers to impingement of the catheter between
the clavicle and the first rib. This can result in fracture of the catheter or
fragmentation.
Central Venous Catheters
Summary of complications
Malposition
Corresponding artery—tip heads toward aorta
Right atrium—cardiac perforation
Right ventricle—arrhythmia or cardiac perforation
Inaccurate central venous pressure measurement
Pneumothorax—usually immediate, may be delayed
Ectopic infusion of fluid into mediastinum or pleural space
Catheter breakage and embolization
Inadvertent puncture of subclavian artery
Local bleeding—small apical extrapleural opacity
More significant bleeding—larger extrapleural opacity
Air embolization—air seen in main pulmonary artery on CXR/CT
Clot formation
“Pinch-off” syndrome between clavicle and first rib
Difficult infusion with arms down
Thrombosis
Fracture/embolization of catheter fragment
Swan-Ganz Catheters
Swan-Ganz Catheters
Purpose
Swan-Ganz (pulmonary artery flotation) catheters are placed to aid in
the differentiation of cardiogenic from noncardiogenic pulmonary edema
by allowing the clinician to monitor pulmonary capillary wedge pressure,
reflecting left atrial pressure and left end-diastolic volume, via a central
channel. Another channel allows assessment of central venous
pressure and cardiac output. A third channel connects to an inflatable
balloon at the catheter tip, which when inflated causes the tip to float
distally through the arterial system and when deflated causes it to
resume a more central position.
Swan-Ganz Catheters
A Caveat
Despite research indicating that radiographic findings allow a more
accurate means of distinguishing between cardiogenic versus
noncardiogenic edema, SG catheters are still in widespread use
throughout all medical centers.
Milne E.N., et al. “The radiologic distinction of cardiogenic and noncardiogenic edema.” American Journal of
Roentgenology. 144(5):879-94, 1985 May.
Swan-Ganz Catheters
Access and Placement
Access is usually gained via the
subclavian vein, but jugular and
femoral vein approaches are also
employed via use of a sheath
called a cordis that facilitates
advancement and withdrawal of
the catheter and can provide
short-term venous access once
the SG is removed. The catheter
tip is ideally positioned within the
left pulmonary artery or the
proximal interlobar artery.
The following radiograph
demonstrates a SG catheter in
the proper position.
Click to locate the NGT.
NGT
Click to locate the ETT.
NGT
Tip of ETT
Click to locate the SGC.
NGT
Tip of ETT
SGC
Click to proceed.
Swan-Ganz Catheters
What’s the diagnosis in the following chest radiograph?
Click for a hint.
Is the SGT in the
right place?
Click for another hint.
Is the SGT in the
right place?
No, in fact—it’s
inserted too
distally. And
complicating
things even more
is this lucency,
which is…?
Click for the answer.
Swan-Ganz Catheters
Complications:
Pulmonary infarction can also arise as a result of a persistently inflated
balloon obstructing a major pulmonary artery. The inflated balloon
appears as a 1-cm rounded radiolucency at the catheter tip. It should be
inflated only when pressure measurements are being taken, and never
while chest radiography is being performed. Dr. Gosselin will hunt you
down if you do this!
Swan-Ganz Catheters
What’s the finding in the following chest radiograph?
Click for a hint.
Click for the answer.
Swan-Ganz Catheters
Complications
Aberrant insertion of the SG catheter can also result in pulmonary artery
rupture, pulmonary artery pseudoaneurysm, pulmonary artery to
bronchial tree fistula, balloon rupture, and intracardiac knotting of the
catheter. Other complications of SG catheters are similar to those that
can occur with CVP lines. Also, redundancy or coiling of the SG catheter
in the right heart can irritate the conduction bundle and induce
dysrhythmias.
Swan-Ganz Catheters
Complications
The risk of pulmonary infarction increases the more distally the catheter
tip is advanced, as the vessel diameters approach that diameter of the tip.
Likewise, clot formation about the tip can lead to occlusion of the vessel in
which it resides. Infarctions can be recognized on CXR by the
appearance of patchy airspace opacification that is often wedge-shaped
and subpleural in location.
Swan-Ganz Catheters
Summary of Complications
Complications associated with central venous pressure catheter placement
Pulmonary infarction
Distal placement of catheter tip
Failure to deflate balloon
Arrhythmia
Catheter tip in right atrium or right ventricle
Excessive coiling or redundancy of catheter tubing in right heart
Pulmonary artery pseudoaneurysm
Pulmonary artery rupture
Pulmonary artery to bronchial tree fistula
Intracardiac knotting of catheter
Balloon rupture
Intra-Aortic Balloon Pumps
Intra-Aortic Balloon Pumps
Purpose
The intra-aortic balloon pump consists of a long inflatable balloon 2628cm in length surrounding the distal end of a centrally placed catheter.
It is used in the setting of cardiogenic shock to enhance cardiac function.
Intra-Aortic Balloon Pumps
Access and Placement
The balloon pump is introduced via the femoral artery and advanced
retrograde into the thoracic aorta. The balloon is ideally situated with the
tip located just distal to the left subclavian artery at the level of the aortic
arch. Such placement ensures maximal augmentation of diastolic
pressures in the proximal aorta. Inflation of the balloon during diastole
increases diastolic pressure, enhancing perfusion of the coronary
arteries and oxygen delivery to the myocardium. Deflation of the balloon
during systole creates a vacuum within the vessel lumen, decreasing
ventricular afterload and enhancing forward blood flow.
The following radiograph demonstrates an IABP in the proper position.
Click to locate the SGC.
SGC
Click to locate the IABP tip.
Tip of IABP
SGC
Click to locate the IABP proper.
Tip of IABP
SGC
IABP
Click to proceed.
Intra-Aortic Balloon Pumps
Complications





Even with ideal positioning, the long lumen of the IABP traverses the
ostia of the celiac trunk, superior mesenteric artery, inferior mesenteric
artery, and renal arteries and can lead to occlusion of these vessels
(mesenteric ischemia, renal failure).
Too proximal a placement of the IABP can lead to obstruction of the left
subclavian artery or cerebral embolus.
Too distal a placement of the IABP results in suboptimal counterpulsation
during diastole.
Aortic dissection and death can rarely occur with advancement of the
catheter during IABP placement.
Potential complications also include traumatic platelet and red blood cell
destruction, peripheral emboli, balloon rupture with resultant gas
embolus, and vascular insufficiency of the catheterized limb.
Intra-Aortic Balloon Pumps
Summary of Complications
Balloon advanced too far
Obstruction of left subclavian artery
Cerebral embolus
Balloon not advanced far enough
Inadequate counterpulsation during diastole
Aortic dissection
Reduction of platelets
Red blood cell destruction
Emboli
Balloon rupture with gas embolus
Renal failure (balloon occlusion of renal artery)
Vascular insufficiency of catheterized limb
Endotracheal Tubes
Endotracheal Tubes
Purpose
Intubation of the airway by oral or nasal ETT (or alternatively by
cricothyroidotomy or tracheostomy) and mechanical ventilation may be
required in situations involving airway obstruction, disorders of gas
exchange, or failure of the airway’s protective mechanisms. ETTs help
prevent large aspirations, but small aspirations still occur continuously.
Endotracheal Tubes
Access and Placement
Most ETTs are radiopaque or feature an
opaque tip to facilitate evaluation of
placement by chest radiography. The tip
should be located at least 3 to 4 cm above
the carina (roughly at the level of T6 on
portable CXR)—ideally at the level of T4—
and at least 3 to 4 cm below the vocal cords
(roughly C6) in adults. The ETT moves with
the chin: With extension of the neck from
the neutral position, the tip recedes
cephalad up to 2 cm; with flexion, the tip
advances caudad up to 2 cm. It is thus
imperative to determine the patient’s head
position before making any
recommendations to reposition the ETT.
The following radiograph demonstrates an
ETT in the proper position.
Click to locate the ETT.
Tip of ETT
Click to locate a helpful landmark.
Tip of ETT
Carina
Click to locate more landmarks.
T1
T2
T3
Tip of ETT
T4
Carina
Click to proceed.
Endotracheal Tubes
What’s the finding in the following chest radiograph?
Click for a hint.
Click for the answer.
Endotracheal Tubes
Complications
The cuff (balloon) of the ETT should be inflated to fill the lateral tracheal
walls (i.e., equal to or slightly greater than the diameter of the trachea to
provide a secure seal), but it should not be bulging, as in the preceding
radiograph. Also, in the preceding radiograph the ETT has not been
advanced far enough into the trachea before the cuff, residing in the
hypopharynx, was inflated. Placement of the ETT too near the vocal
cords may lead to vocal cord injury when the cuff is inflated.
Endotracheal Tubes
What’s the diagnosis in the following chest radiograph?
Click for a hint.
What does this
lucent tract
represent?
Click for another hint.
What does this
lucent tract
represent?
What’s happened
to the left lung, and
why?
Click for the answer.
Endotracheal Tubes
Complication
Advancement of the ETT into the right mainstem bronchus is one of the
most common errors encountered during intubation. The left lung
typically collapses when this occurs. The left mainstem bronchus is
clearly visible, as indicated by the first hint.
Endotracheal Tubes
Complications





Insertion of the ETT into the esophagus is a life-threatening
complication. On CXR, the ETT will be situated just lateral to the
trachea. As with pharyngeal placement, the stomach becomes
markedly distended, though aspiration does not occur due to
occlusion of the esophagus by the ETT cuff.
Pharyngeal placement of the ETT results in disrupted mechanical
ventilation and may distend the stomach with air, with aspiration of
gastric contents.
Intubation can result in tracheal laceration with an overinflated cuff
herniating through the tear on CXR. A concomitant pneumothorax or
pneumomediastinum may also be observed.
Overinflation of the cuff may occur with inadvertent hyperinflation,
intraesophageal placement, chronic intubation, or tracheomegaly.
ETT placement is associated with an increased incidence of sinusitis
due to mucosal edema and obstruction of sinus drainage.
Tracheostomy Tubes
Tracheostomy Tubes
Purpose
Tracheostomy tubes are usually placed one to three weeks following ETT
placement in patients requiring ongoing mechanical ventilation or tracheal
suctioning.
Tracheostomy Tubes
Placement and Positioning:
A stoma is created at the level of the third
tracheal cartilage, though which the
tracheostomy tube is inserted. Like ETTs,
the tip should be situated several
centimeters above the carina; unlike ETTs,
however, the position of the tip does not vary
considerably with head flexion or extension,
and the cuff should not extend to the
tracheal wall.
The following radiograph demonstrates an
NGT in the proper position.
Note that there is slight rotation in this view. Click to proceed.
Tracheostomy Tubes
Note
It is not uncommon to observe slight subcutaneous emphysema in the
neck and upper mediastinum following surgical placement of the
tracheostomy tube. It is usually mild and self-limited, and patients and
their families should be reassured accordingly.
http://www.perspectivesinnursing.org/v1n1/Dixon.html
Tracheostomy Tubes
What’s the finding in the following chest radiograph?
Click for a hint.
What’s the expected
orientation of a
properly placed ETT?
Click for the answer.
Tracheostomy Tubes
Complications
Massive, clinically significant subcutaneous emphysema can occur as a
result of paratracheal insertion or tracheal perforation (the latter depicted
in the preceding radiograph). Pneumothorax can occur if the apical
pleural space is breached during surgery but can also arise in the setting
of tracheal perforation. Subsequent radiographs of the preceding patient
should be meticulously checked for all of the above sequelae following
surgical revision of the tracheostomy tube placement.
Tracheostomy Tubes
Complications


Some degree of mucosal injury occurs in every patient undergoing
placement of a tracheostomy tube due to mucosal irritation and bacterial
colonization. A few cases may progress to ulceration and, potentially,
cartilage necrosis.
Mucosal edema, erythema, and superficial ulcerations following extubation
usually heal of their own accord. Deep ulcerations, however, can lead to
permanent laryngeal scarring, tracheal stenosis, and tracheomalacia.
These may not fully manifest for several weeks to months following
extubation, and all subsequent CXRs should be evaluated for any
laryngeal or tracheal narrowing.
Tracheostomy Tubes
Complications
Barotrauma and air leak can occur in up to 50% of patients, and those
with adult respiratory distress syndrome are at increased risk. Air
escapes from the ruptured alveoli and dissects medially along the
bronchovascular connective tissue towards the mediastinum. If the
pressure increases, air can track cephalad into the neck or follow the
esophagus caudad to the retroperitoneum, continuing along the anterior
and posterior perirenal space and properitoneal fat. In men, if this does
not sufficiently decompress the mediastinum, air can dissect along the
anterior abdominal and chest wall and into the scrotum. Ultimately, air
can rupture into the peritoneum and the into the pleural space by way of
the mediastinal parietal pleura.
Tracheostomy Tubes
Summary of Complications
Malposition
Right mainstem ETT intubation leads to hypoventilation or collapse of left lung
Dislodgment from trachea interrupts mechanical ventilation
Placement just beyond vocal cords leads to vocal cord injury when cuff is inflated
Placement within esophagus—look for:
Gastric dilatation
Overinflated cuff lung hypoventilation
Lateral placement of tube
Tracheal or laryngeal laceration—look for:
Pneumothorax
Pneumomediastinum
Tracheostenosis
Tracheomalacia
Chest Tubes
Purpose
Chest tubes may be required to evacuate the pleural space of air, blood,
pus, or other pleural fluid.
Chest Tubes
Placement and Positioning
The side hole of the chest tube is marked by an interruption in the
radiopaque strip that runs the length of the tube. This hole should be
located medial to the inner margin of the ribs.
The following radiograph demonstrates a chest tube in the proper
position.
Click to locate the chest tube.
Click to proceed.
Chest Tubes
What’s the finding in the following chest radiograph?
Click for a hint.
Note the smooth
curvature of the
chest tube.
Click for the answer.
Chest Tubes
Complications
The chest tube is likely located within a fissure when it reproduces the
anatomy of the major or minor fissure as in the preceding radiograph
(tube resides within the right major fissure). Frontal CXR ideally should
demonstrate a vertically oriented radiopacity; a more horizontal course
with gentle curvature of the chest tube (red arrow) suggests location
within a fissure. Such location may result in occlusion of the tube by the
surrounding lung parenchyma, rendering suctioning ineffective.
Chest Tubes
What’s the finding in the following chest radiograph?
Click for a hint.
What does this
lucency
represent?
Click for the answer.
Chest Tubes
Complication
Other errors of placement include placement of the chest tube within the
subcutaneous tissues, advancement into the mediastinum, within the lung
parenchyma, or through the liver, spleen, or diaphragm (as in the
preceding radiograph—note the area of lucency representing colonic air),
resulting in a bronchopleural fistula, hemorrhage, or infection. Following
removal of the chest tube there may be a residual pleural or parenchymal
line on CXR representing the tube’s prior course. This should not be
mistaken for the visceral pleural edge of a pneumothorax. Rapid lung
reexpansion may result in pulmonary edema when the amount of pleural
fluid removed is large (>1.5L).
Nasograstric Tubes
Nasogastric Tubes
Purpose
NG tubes are used for suctioning gastric contents (as in treatment of
small-bowel obstruction).
Nasograstric Tubes
Access and Positioning
The tip of the NG tube
should reside within the
stomach, with the side port
lying beyond the
gastroesophageal junction.
The NG tube appears as a
1-cm diameter tubing with
a single thick radiopaque
stripe and a break in the
stripe 6 cm from the tip
representing the side port.
The following radiograph
demonstrates an NGT in
the proper position.
Click to locate the ETT.
Tip of ETT
Click to locate the SGC.
Tip of ETT
SGC
Click to locate the NGT.
NGT
Tip of ETT
SGC
Click to proceed.
Nasogastric Tubes
Complications
Most relate to malpositioning, such as incomplete insertion and/or tube
coiling within the esophagus, which predisposes the patient to aspiration.
Dobhoff Feeding Tubes
Dobhoff Feeding Tubes
Purpose
Infusion of enteral nutritional support or medications.
Dobhoff Feeding Tubes
Access and Positioning
Dobhoff tubes are inserted
orally or nasally and are
ideally situated within the
third part of the duodenum,
almost to the ligament of
Treitz, although placement
within the proximal
duodenum is adequate. It
appears as a thin 3-mm tube
with a weighted radiopaque
distal tip. The side port lies
just proximal to the weighted
tip.
The following radiograph
demonstrates a Dobhoff in
the proper position.
Click to locate a helpful landmark.
Esophagus
Click to locate the ETT.
ETT
Esophagus
Click to locate the Dobhoff tube.
ETT
Esophagus
Dobhoff
Click to proceed.
Dobhoff Feeding Tubes
Complications
Dobhoff tubes may inadvertently be introduced into the lungs (with tube
feeds leading to overwhelming pneumonia), pleural space, or even
through the diaphragm, or the tip may be placed in the hypopharynx or
esophagus, which may perforate during insertion. Esophageal
perforation may manifest as pleural effusion, pneumomediastinum,
extraesophageal location of the tube, mediastinal widening, and
mediastinal air-fluid levels that can be detected radiographically.
References
Amorosa, J.K. Essentials of Radiology. CD-ROM 1999.
Collins, J., and Stern, E.J. Chest Radiology: The Essentials. Lippincott Williams & Wilkins:
Philadelphia 1999.
Dixon, L. “Tracheostomy: Postoperative Recovery.” Perspectives: Recovery Strategies from the
OR to Home. LINK
Milne E.N., et al. “The radiologic distinction of cardiogenic and noncardiogenic edema.” American
Journal of Roentgenology. 144(5):879-94, 1985 May.
Mullan, B. “Positions of Tubes and Lines on Chest Films.” Virtual Hospital. LINK
Biffi M., et al. “Left superior vena cava persistence in patients undergoing pacemaker or
cardioverter-defibrillator implantation: a 10-year experience.” Chest. 120(1):139-44, 2001 Jul.