2. • Chest X-rays are commonly used to confirm
correct positioning of certain medical devices
and to check for associated complications
following placement or misplacement
3. ET Tubes - Position
• The tip of an endotracheal tube (ET tube) should be
located in the trachea above the carina
• To see the carina use a good quality screen in a
darkened room
• A chest X-ray is often acquired following placement of an
endotracheal tube (ET tube) to determine the position of
its tip
• The trachea, carina and main bronchi are almost always
identifiable on a chest X-ray image, as long as the image
is viewed on a high quality screen in a darkened room
4. Correct endotracheal (ET) tube position
• As ET tubes are fixed at the mouth, neck position affects
the location of the ET tube tip
• Neck extension pulls the tube superiorly and neck flexion
pushes the tube inferiorly
• Neck rotation may also displace the tube
• On a radiograph acquired with the neck in the neutral
position, a distance of 5-7 cm above the carina is
generally considered acceptable for adults
• In this position it is unlikely that the tube could be pushed
beyond the carina or pulled towards the vocal apparatus
• Use the measurement tool provided by the digital
viewing software and make sure the position is
documented
5. Tracheobronchial anatomy
•The trachea is located on the right side of the aortic knuckle and slightly to the right
of the midline
•The carina is the point at which the lower edge of left and right main bronchi meet
6. Correct ET tube position
• The ET tube tip is correctly located in the trachea, 5 cm above the carina
• Most ET tubes have an inflatable cuff which forms a seal against the
trachea; these cuffs are not visible radiographically
7. Carina position
• If the carina is not clearly visible, then the vertebral
bodies can act as an anatomical landmark to estimate
carina position
• In most individuals the carina is located between the
levels of the 5th and 7th thoracic vertebral bodies
• Note:
• This is an inaccurate method for locating the carina and
if the patient is kyphotic or has a chest wall deformity, or
if the image is a kyphotic or lordotic view, then this
method should not be relied upon
8. Carina position
•The carina is more difficult to identify in this image so the vertebral bodies can be
used as a rough estimate of carina position
•If the vertebral bodies themselves are not seen clearly, as in this case, the ribs
can be used as landmarks to locate the correct vertebral level, and hence the
approximate level of the carina
9. Tracheostomy tubes
• Tracheostomy tubes are fixed at the skin by a flange
located immediately anterior to the trachea
• Therefore, the tip of a tracheostomy is less susceptible
to change in position on neck flexion or extension than is
the case for an ET tube
• Tracheostomy tubes are positioned so that their tips are
located at a midpoint between the upper end of the tube
and the carina
10. Carina position
•This tracheostomy tube tip is located 6 cm above the carina - approximately
half the distance between the top of the tube and the carina
11. ET Tubes - Complications
• If inserted too far, an endotracheal tube (ET tube) can
enter the right or left main bronchus
• This results in ventilation of a single lung and can result
in collapse of the contralateral lung or a lobe of the
intubated lung
• Accidental intubation of a bronchus is more common on
the right because the right main bronchus is more
vertically orientated than the left main bronchus
12. ET tube misplaced at carina
•This ET tube tip is incorrectly located at the level of the carina and nearly enters
the right main bronchus
•Although both lungs are currently ventilated there is a risk of intubation of a single
bronchus on neck movement
•This tube should be repositioned by a trained individual
13. ET tube misplaced in right main
bronchus
•The ET tube has entered the right main bronchus
•This tube should be repositioned by a trained individual
14. Misplaced ET tube with lung
collapse
•The ET tube is within the right main bronchus
•The tube and its cuff occlude the orifice of the left main bronchus which is not visible
•Consequently the left lung is not ventilated and has collapsed
15. Pneumomediastinum and surgical emphysema
•The ET tube tip is adequately positioned, 5 cm above the carina
•Surgical emphysema is readily visible in the soft tissues of the neck on the right
•Pneumomediastinum (gas in the soft tissues of the mediastinum) is often more
difficult to identify
•In this image the mediastinum is outlined by a thin white line (arrowheads)
•This line is the mediastinal pleura which is separated from the mediastinum by gas
•These are the typical appearances of pneumomediastinum
16. • NG Tubes - Position
• If aspiration of gastric fluid following placement of an
nasogastric (NG) tube is unsuccessful, then a chest
X-ray can be used to help determine tube position
• Oesophagus anatomy
• A correctly positioned NG tube passes vertically
down the oesophagus into the stomach
• As the oesophagus is not visible on a plain chest X-
ray, it is essential to have an understanding of its
anatomical position in relation to other visible
structures
17. Oesophagus anatomy
•The oesophagus passes posteriorly and slightly to the left side of the trachea
•The oesophagus is located immediately to the right of the aortic knuckle
•From this level the oesophagus passes down in the midline to the level of the
gastro-oesophageal junction which is at the level of the diaphragm
18. Correct NG tube position
•Check the tube passes vertically in the midline, or near the midline, below the level
of the carina (red ring)
•The tube MUST NOT follow the course of the right or left main bronchi
•Check the tube continues vertically in the midline down to the level of the
diaphragm where it passes through the gastro-oesophageal junction (orange ring)
•The tip of the tube (green ring) must be visible below the diaphragm and on the
left side of the abdomen - 10 cm or more beyond the gastro-oesophageal junction
19. NG tube tip position - Image 1 - tip not visible
•The tube passes in the midline below the level of the carina (red ring)
•The tube does not enter the right or left bronchi
•The tube stays in the midline below the carina to the level of the gastro-
oesophageal junction (orange ring)
•The tip of the tube is projected below the lower edge of the image and so its
position cannot be determined
20. NG tube tip position - Image 2 - tip visible
An additional image shows the NG tube tip located below the diaphragm on the left
side of the abdomen
21. NG tube misplacement - Looped
•The tube passes below the level of the carina and does not follow the course of the
right or left bronchi
•The tube is, therefore, in the oesophagus and has not been inhaled
•The tube is looped back on itself so its tip is located in the upper oesophagus
•Feeding via a tube in this position would risk aspiration of the feed into the lungs
•The tube must be repositioned
22. Tube misplacement in right main
bronchus
•The tube follows the course of the right main bronchus
•Its tip is projected over the lower zone of the right lung
•The NG tube has been inhaled rather than swallowed
•The tube must be removed and repositioned
23. Tube misplacement in proximal stomach
•This tube has reached the stomach but it is not in a safe position for feeding
•If left in this position there is a risk of it being displaced proximally when the
patient changes posture
•For safe positioning it is recommended that a NG tube tip is located at least 10
cm distal to the gastro-oesophageal junction (green target area)target area)
24. Tube misplacement in duodenum
•The gastroduodenal junction is located just to the right side of the midline
(spine indicates midline)
•To ensure the tube is not in the duodenum,its tip is ideally placed more
proximally in the stomach to the left of the midline
•For feeding into the stomach this tube should be withdrawn and its position
confirmed either by a further attempt of aspiration of gastric fluid or by
repeating the X-ray
25. CV Catheters - Position
nts
• Positioning the tip of a central venous catheter (CVC)
within the superior vena cava (SVC) at or just above the
level of the carina is generally considered acceptable for
most short-term uses, such as fluid administration or
monitoring of central venous pressure
• Ideally the distal end of a CVC should be orientated
vertically within the SVC
• CVCs placed for the purpose of long term chemotherapy
may be placed more inferiorly at the cavo-atrial junction -
the junction of the SVC and right atrium (RA)
• Catheters used for haemodialysis may be placed at the
cavo-atrial junction or even in the RA itself
• Positioning the catheter tip too proximally, for example in
the right or left brachiocephalic veins, is associated with
increased risk of line infection and thrombosis
26. Anatomy
• The lower part of the SVC is surrounded by the
pericardial reflection; this is where the upper pericardium
folds back on itself to form a sac
• Positioning a CVC tip within the SVC and below the level
of the pericardial reflection is associated with a small risk
of pericardial tamponade
• Neither the SVC nor the pericardial reflection are visible
on a chest X-ray
• As the carina is a visible structure, which is located
above the level of the pericardial reflection, it can be
used as an anatomical landmark to help determine the
level of a CVC tip within the SVC and above the
pericardial reflection
27. Superior vena cava (SVC) anatomy
•The internal jugular and subclavian veins join to form the brachiocephalic veins
(asterisks)
•The brachiocephalic veins (also known as the innominate veins) join to form
the SVC
•The SVC is located to the right side of the mediastinum above and below the
level of the carina
28. SVC anatomy - detail
•The pericardial reflection is located below the level of the carina
•The cavo-atrial junction is located approximately the height of two vertebral
bodies below the level of the carina
29. • Right-sided catheters
• CVCs are most commonly inserted via the right internal jugular vein
• Right internal jugular catheters are positioned on the right side of
the neck, and pass vertically from a position above the clavicle
• Left-sided catheters
• Left-sided catheters approach the SVC at a shallow angle such that
they may abut the right lateral wall of the SVC
• They may need to be inserted further so the distal end obtains a
vertical orientation
• This may mean locating the tip below the level of the carina
• In this position the risk of vessel wall erosion is reduced, but with a
small increased risk of pericardial tamponade
• Long-term catheters
• Catheters which are used for long-term administration of
chemotherapy drugs (inserted either from the right or left) are
usually positioned more inferiorly, at the level of the cavo-atrial
junction
• These catheters are usually inserted by radiologists or other
specially trained staff
30. Right internal jugular vein catheter
•The catheter is orientated vertically
•The tip is projected over the anatomical location of the SVC - approximately
1.5 cm above the level of the carina
•This is an ideal position for right-sided catheters for fluid administration and
venous pressure monitoring, but not for long-term chemotherapy or dialysis
31. Right subclavian vein catheter
•The catheter passes below the level of the clavicle
•The distal catheter is orientated vertically
•The tip is located 1 cm above the level of the carina
32. Left subclavian vein catheter
•This left subclavian catheter is located with its tip below the level of the carina
•Positioning the tube vertically avoids abutment of the tip against the right
lateral wall of the SVC
33. Long term catheter - PICC line
•This peripherally inserted central catheter (PICC) is correctly located with its tip
at the level of the cavo-atrial junction - approximately the height of two vertebral
bodies below the level of the carina
•This is often considered a preferable location for long-term catheters
34. CV Catheters - Complications
Iatrogenic pneumothorax
•This right subclavian catheter is adequately positioned with its tip in the
superior vena cava
•Positioning was complicated by pneumothorax due to pleural injury
35. CVC in left brachiocephalic vein
•The tip of this catheter is projected over the left brachiocephalic vein rather
than the SVC (superior vena cava)
•A nasogastric tube is also in situ (not fully imaged)
36. Catheter in right atrium
•This peripherally inserted central catheter (PICC) was aimed to be inserted with
its tip at the level of the cavo-atrial junction (the height of two vertebral bodies
below the carina)
•The PICC has been inserted too far with its tip in the right atrium (RA)
•Note: Some large haemodialysis catheters are designed to be placed with their
tip in the RA
37. Horizontal positioning in SVC
•Catheters placed via a left-sided approach are prone to being positioned
nearly horizontally rather than vertically within the SVC
•Catheters which contact the lateral wall of the SVC in this way may cause
vessel erosion if positioned long term, and should therefore be placed so the
tip is orientated vertically
•A nasogastric tube is also in situ (not fully imaged)
38. Internal jugular catheter - misplaced
•CV catheters may take an incorrect course and end with their tip in completely
the wrong place
•This left internal jugular catheter has entered the left subclavian vein
•The catheter needs to be repositioned
•Note also the ET tube, the external cardiac monitoring wire, and the lung
shadowing - due to pulmonary oedema in this case
39. Chest Drains - Position
• A pleural effusion or a pneumothorax can be treated by
positioning a tube into the pleural cavity
• Chest drains are usually inserted through the chest wall
in the mid-axillary line
• The superior/inferior and medial/lateral positioning of the
tube can be determined on a chest X-ray
• For treatment of a pneumothorax the tube tip is aimed
towards the upper pleural cavity and for treatment of a
pleural effusion towards the lower part of the pleural
cavity
40. Chest drain - treatment for pneumothorax
•A large chest drain is positioned with its tip pointing superiorly within the pleural
cavity
41. Chest drain - close up
•Chest drains are variable in design
•This tube has a radio-opaque tip and a marker strip along the edge
•Gaps in the marker indicate the position of holes in the side of the tube
42. Chest drain - treatment for pleural
effusion
•The tube is appropriately placed towards the lower part of the pleural cavity
43. Chest Drains - Complications
Iatrogenic pneumothorax
•This chest drain was placed to treat a pleural effusion
•The effusion, which was very large, has been nearly completely drained leaving
only a relatively small volume of residual fluid
•Injury to the lung at the time of drain insertion has led to formation of a large
pneumothorax
44. Surgical emphysema
May result from incorrect tube positioning such that the end is located within
soft tissues of the chest wall
This may also occur if the tube becomes displaced following correct tube
placement
•This chest drain is located within soft tissues of the chest wall
•There is a pneumothorax (asterisks) and widespread surgical emphysema
over the left chest wall
