External devices [3,4]
Enteric Tubes
- Function and position: The ideal position varies between the gastric antrum or duodenum when the enteric tube is used exclusively for feeding and within the stomach when it is used for suction or medication administration (figure 1).
- When it is located in digestive tube, it may cause aspiration,
when the tip is located in distal esophagus and reflux occurs or when the patient has gastric hernia and the tip remains in the herniated stomach (figure 2).
It sometimes requires endoscopic control to set the tube in the abdominal stomach,
or duodenum (figure 3).
It may cause also pharyngeal or esophageal perforation,
with pneumomediastinum,
subcutaneous emphysema and other exceptional complications as we show in the next case.
It is a 77-year-old man in the ICU due to an acute ischemic brain stroke.
He had a history of laryngeal tumor treated by local radiotherapy.
A nasogastric tube was set without difficulties and when aspiration was made to be sure of its location,
dark and hot blood filled the syringe,
coagulating immediately.
It seemed to be in the venous system.
PCXR was made (figure 4) and nasogastric tube seemed to be a central venous catheter,
going down trough the superior cava vein,
with a loop,
and going up,
with the tip in the right internal jugular vein.
CT was made (figure 5) and showed how the tube perforated the pharynx and achieved the venous system through the right thyrocervical trunk.
The tube hooked one of the pacemaker´s lead,
so the patient was referred to the angiography room where it was retired by a bifemoral approach (figure 6).
- When it is located in tracheobronchial system,
it may cause bronchopulmonary injury; pneumothorax; pulmonary laceration or contusion; and even pneumonia when it is used for feeding.
We present a case (figure 7) in which the nasogastric tube goes down from the trachea,
to the left main bronchus and the tip is in a segmental bronchus of the inferior left lobe.
Feeding was initiated and the X-Ray chest realized after some hours showed a bronchopneumonia which corresponded with feeding in lung parenchyma.
Endotracheal and Tracheostomy Tubes
- Function and position: Endotracheal tube (figure 8) is used for mechanical ventilation and tracheostomy tube (figure 9) is secondary to laryngeal surgery or used to improve breath efficacy in some patients.
The tip of the tube should be 5 cm above the carina or above the aortic knob,
with patient’s head in a neutral position.
Maximum displacement of the tube ranges between 2 and 4 cm with neck flexion or extension.
- Malposition: extubation or main bronchus intubation,
usually the right (it causes atelectasis,
iatrogenic pneumothorax).
- Tracheal rupture is a rare but severe complication,
which manifests as pneumothorax and pneumomediastinum.
- Tracheal stenosis after prolonged intubation,
which may cause problems in posterior intubations.
- Intubation of the esophagus is also rare but devastating,
and may be detected as an air column parallel to the trachea or stomach distended by gas.
Chest Tubes
Pleural
- Function and position: They are used to evacuate fluid,
air or mixed collections from the pleural space.
The tube is placed anterosuperiorly when a pneumothorax is detected and posteroinferiorly to evacuate a pleural effusion (figure 10)
- Inadequate function due to malposition. If the tube is posterior or is not high enough,
will not evacuate the air.
If it is anterior or in a pulmonary fissure,
will not evacuate appropriately the pleural effusion.
- Pulmonary atelectasis due to the tube mark is common,
but usually solved when the tube is retired.
When a chest tube is inserted into the pulmonary parenchyma,
pulmonary contusion or laceration may be seen.
In other cases a bronchopleural fistula may be caused,
with recurrent pleural effusion.
In extreme cases diaphragmatic or hepatic laceration may be seen.
Intercostal artery bleeding is an uncommon but sometimes several procedural complication,
because if it is not detected on time,
the patient could even die.
Mediastinal
- Function and position: They are used after cardiac or mediastinal surgery.
They can have different locations,
just depending on the type and location of the surgery (figures 11,
12).
- Inadequate function is usually due to malposition,
as the chest tubes.
Liquid may accumulate and pericardial effusion or even cardiac tamponade is possible.
In this case there was a mediastinal hematoma as a surgical complication detected as an apparent increase in the cardiac size (figure 13) and diagnosed by echocardiography.
Venous Catheters
- Function and position: They are used for administering fluids,
medication and nutrition,
for monitoring hemodynamic function and for performing hemodialysis.
By PCXR we can distinguish the type of catheter,
with one lumen (figure 14) ,
two (figure 15) or even three (figure 16) .They may be inserted via the subclavian vein or via the internal jugular veins (figure 14,
17) (central venous catheters) or peripherally in upper-extremity veins (figure 18).
The tip should be in the superior vena cava,
slightly above the right atrium and beyond the most proximal venous valve to avoid the risk of thrombosis.
It is also very common to see subcutaneous reservoir in oncologic patients,
which may have one (figure 19) or two lumen (figure 20),
depending on the type of chemotherapy the patient receives.
- Aberrant positioning is quite common.
Usually it is located within the right atrium,
where there is risk of arrhythmias (figure 21),
or intravenous.
Intravenous locations may be: the veins of the upper extremity (figure 22),
cephalad within the internal jugular vein (figure 23),
traversing midline to the contralateral brachiocephalic vein,
or going down to the inferior cava vein (figure 24) or suprahepatic vein (figure 25).
These venous locations do not usually cause complications.
- Pneumothorax may be secondary to pulmonary damage in the moment of venous puncture (figure 26).
It does not usually require chest tube.
If it is early detected,
a simple puncture might control it.
- Hemothorax may be caused by a traumatic puncture,
as in this case.
There was a first non-effective puncture,
and secondly a jugular access was achieved.
After two days,
the patient felt wrong and an important hemothorax with pneumothorax was found in CT,
surely as a consequence of the first puncture (figure 27)
- Miocardial rupture,
pericardial tamponade,
and vessel perforation are rare but severe complications,
quite difficult to detect by PCXR.
- Venous thrombosis is not infrequent,
and may not be detected by PCXR.
Nevertheless it may cause pulmonary thromboembolism,
and so,
early detection and treatment is required.
Pulmonary Artery Catheters or Swan-Ganz catheters
- Function and position: They are used to measure pulmonary artery pressure,
pulmonary capillary wedge pressure and cardiac output.
Actually,
we can usually see them in the first 48 hours after hepatic transplantation.
The tip of the catheter should be in the right main pulmonary artery (figure 28A),
left main pulmonary artery (figure 28B) or in the proximal interlobar artery,
in the measurement moment.
It may be proximal to these points when the catheter is not measuring.
If we detect the tip beyond these vessels,
the catheter should be retracted.
- As we have seen in venous catheter,
pericatheter thrombus is possible,
but in arterial catheters consequences can be quite more severe: pulmonary artery occlusion and pulmonary infarct.
- Vascular damage (pulmonary hemorrhage and pseudoaneurysm)
- Intravascular knots are possible,
and sometimes,
as in our case,
the catheter must be retired in the angiography room.
- Pneumothorax or hemothorax,
arrhythmias and cardiac perforation are possible,
as we have seen in venous catheters.
Intraaortic Balloon Pump (IABP)
- Function and position: The intra-aortic balloon pump is a balloon device that inflates during systole to assist coronary perfusion and deflates during diastole to decrease cardiac afterload.
It has a radio-opaque tip that should be within the proximal descending aorta,
just distal to the origin of left subclavian artery (figure 29).
- Cerebral or left upper-extremity ischemia is caused if the tip is located too proximally.
- If the tip is located too distal,
occlusion of the abdominal aortic branch arteries may occur and renal and mesenteric ischemia happens.
- Limb ischemia is also possible if the tip is located too distal.
- Aortic rupture and balloon rupture with air embolization are other rare complications.
Cardiac Pacemakers and defibrillators
- Function and position: Cardiac pacemakers are not specific devices of critically ill patients,
but are frequently seen in them.
Cardiac pacemaker may have different number of leads (figures 30,
31),
may have the typical covered leads of defibrillators (figure 32),
or may be epicardic pacemakers (figures 33,
34). And in severe patients,
with risk of cardiac failure,
we can see a defibrillator patch (figures 32,
35)
- Lead malposition is quite difficult to detect in PCXR,
but it is necessary to describe the apparent location of the leads to help clinical physician to detect malpositions.
- Lead fracture is not uncommon and is clearly seen in the X-Ray (figure 31).
We have found several cases of defibrillator fragments after cardiac transplantation (figure 37).
We can see how a fragment remains in the superior cava vein (figure 36),
in the subclavian vein (figure 36) or how a fragment migrates to liver (figure 38)
- Twiddler syndrome is a rare complication which causes pacemaker dysfunction due inadvertent or deliberate rotation of the pulse generator,
with retraction of the lead,
as in the case we show (figure 39),
which had to be recolocated.
- Myocardial rupture is an uncommon but possible complication.
Other External Devices
We show other external devices which we have found in our daily practice,
quite varied but also quite interesting.
- Epidural catheter (anesthetic). It is common to set an epidural catheter after surgery to control postsurgical pain,
and we can detect them in the PCXR (figure 40).
- Brachitherapy wires in neck tumours (figure 9) or brachitherapy seeds located in the lung parenchyma (figure 41) or which have migrated there from other anatomic regions,
as prostate (figure 42)
- Biliary tubes (figure 43),
TIPS (figure 42) and embolization coils are some of the external devices we can find in cirrhotic patients or after complications of hepatic transplantation.
- It is not as uncommon as we could believe to find vertebroplasty cement embolized in the pulmonary arteries (thromboembolism) (figure 44)
- Pectus excavatum is a morphologic alteration which does not usually requires surgery,
but sometimes,
when cardiac or respiratory functions are altered,
is corrected.
A metallic bar is used,
as we see in this case (figure 45)
- At last,
as an uncommon and difficult image,
we show the X-Ray of a patient,
with a mediastinal collection due to postsurgical esophageal leak,
which communicated with the skin.
We can see the radio-opaque lines of the gauzes introduced in the wound (figure 46).