Malpositioned Lines and Tubes on Chest Radiograph – A Concise Pictorial Review
Chest radiograph is the most performed radiographic examination because of the simplicity in the technique and its clinical utility in both inpatient and outpatient settings. Due to the complexity of the critically ill patients in intensive care units, the performance of daily routine radiographs has been in practice for decades. According to a recent American College of Radiology appropriateness criteria, there is no specific necessity to obtain daily routine chest radiographs.[1,2] However, radiographs are recommended whenever there is a significant change in clinical status, placement and repositioning of support devices, and after any bedside procedures.
A diverse variety of endotracheal tubes is in clinical practice. The parts of the ET tube include an inflatable cuff that will safely secure the trachea to avert air leak and decrease the risk of aspiration.
Positioning of endotracheal tube: Always start with ensuring the ET tube is within the tracheal air column. The normal positioning of the endotracheal tube is always referred to as the distance of the ET tube tip from the carina. The normal position of the carina is at the level of T4-T5 which is used as the landmark for ET tube positioning. Preferably, the ET tube is positioned in the mid-thoracic trachea terminating 3–5 cm from above the carina. Accounting for flexion and extension of neck, a 2 cm ascend or descend from the aforementioned measurements is commonly encountered.
Malpositioned ET tube
Advancement of ET tube inferiorly into the bronchus may result in hyperinflation of the intubated lung and collapse of the contralateral lung. When the ET tube is advanced too far into the right main stem bronchus, the tube will descend into bronchus intermedius and result in the right upper lobe collapse [Figures 1a and b, Figures 2 a and b]. In the case of esophageal intubation, the ET tube lies left lateral to the tracheal walls within a distended esophagus. A lateral or oblique radiograph will be helpful in precisely delineating this malposition.
Tip of ET tube should be positioned 3–5 cm from the carina. Always check the position of head of the patient as it can alter the position of ET tube, with the ET tube moving inward toward the carinal on flexion and moving away from the carina on extension.
There is a wide range of tracheostomy tubes available with different materials, size, and styles. Most tubes have a main shaft (cannula) attached to a neck plate (flange), and cuffed tubes have a pilot balloon, which shows whether the cuff is inflated.
Position of tracheostomy tube: Always look for tracheostomy cannula projecting within the tracheal air column.
Malpositioned tracheostomy tube
It is relatively rare to malposition a tracheostomy tube as compared to the endotracheal tube since they are fixed in position by sutures. When there is suspicion for a malpositioned tracheostomy tube,always check the patient’s position since patient rotation can lead to apparent appearance of tracheostomy tube being malpositioned outside the tracheal air column.
The tracheostomy cannula should project over the tracheal column.
In clinical practice, both weighted and non-weighted enteric tubes are routinely used for feeding and decompression of the stomach respectively. Weighted tubes can be identified by its radiodense tip on a radiograph.
Positioning of enteric tubes
The side port of an enteric tube should be ideally positioned below the gastroesophageal junction for proper functioning and to avoid the potential risk of aspiration.
Malpositioning of enteric tubes
An enteric tube terminating above the diaphragm should be meticulously evaluated for malpositioning, which includes tracheal placement, inadequate positioning, and coiling of enteric tubes within the esophagus [Figures 3-5].
The side port of an enteric tube should be ideally positioned below the gastroesophageal junction.
ESOPHAGEAL TEMPERATURE PROBE
Esophageal temperature probes are routinely used for the monitoring of core body temperature in critically ill patients.
Positioning of temperature probes: Ideal placement at the level T8-T9 intervertebral space has long been considered essential for accurate measurement. Chest radiographs are done to ensure correct positioning.
Malpositioned temperature probes
The most commonly encountered malposition is the temperature probe tip at the neck or proximal thoracic esophagus [Figure 6].
The esophageal temperature probe tip should project over level of T8-9.
CENTRAL VENOUS CATHETERS
There have been dramatic advancements in the image-guided placement of central venous catheters which enable appropriate and precise positioning. Central venous catheters can be categorized into four different groups; the peripherally inserted central catheter is non-tunneled central venous catheters, tunneled central venous catheters, peripherally inserted catheters, and implantable port catheters.
Positioning of central venous catheters
Ideally, cavoatrial junction is at commonly acceptable landmark signifying appropriate positioning. Radiographically, this landmark is defined by the right tracheobronchial angle and carina. Cavoatrial junction typically resides 3–4 cm below the structures, however, there is a great variability in apparent positioning taking into account of lung inflation, patient positioning, and projection of the radiographs.
Malpositioning and other complications of central venous catheters
The interpreting radiologist should perform a meticulous assessment of the course of the central venous catheter and also assess for abnormal course, coiling, kinking, fragmentation, and catheter pinch-off. Central venous catheters placed with tip terminating higher from the cavoatrial junction are prone to have low flow rates, malfunction, and thrombosis. There is also a higher risk of SVC erosion, especially with the left-sided catheter insertion. However, with the lower tip, there is a higher risk for arrhythmia. Central venous catheters that taking a vertical course and terminating toward the left of the spine indicate the presence of left-sided SVC, double SVC, coursing into the internal mammary vein, arterial placement, or maybe extravascular [Figures 8-13].
Tip of central venous catheter should terminate at the cavoatrial junction.
PULMONARY ARTERIAL CATHETER
Swan-Ganz catheters are typically inserted for monitoring pulmonary arterial branch pressures but also used for delivery of medications such as thrombolytic infusions.
Positioning of the Swan-Ganz catheter
Preferentially, the Swan-Ganz catheter tip should terminate centrally within the right or left main pulmonary artery, ideally proximal to the interlobar pulmonary artery.
Malpositioning and complications of Swan-Ganz catheter
If the catheter tip is too distal, it may result in pulmonary infarction or pulmonary hemorrhage, which may be seen as peripheral wedge-shaped peripheral consolidation distal to the catheter. Catheter looping in the right heart made resulting in valvular damage or arrhythmia.
INTRA-AORTIC BALLOON PUMP
IABP catheter is used to improve coronary blood flow during diastole in patients with myocardial ischemia. The interpreting radiologist should be aware of the way IABP is introduced whether it is through the femoral or subclavian arterial approach. This is important to assess for malpositioning and to guide further the tip should be repositioned proximally or distally.
Positioning of IABP
The IABP tip is identified by a radiopaque marker. The tip should be positioned in the proximal descending thoracic aorta, just below (i.e., 2.0 cm) the left subclavian artery take-off and superior contour of the transverse aorta.
Malpositioning of IABP
IABP catheters with their tips placed too proximally can impede the cerebral blood flow and cause stroke [Figure 17]. IABP catheters with their tips placed too distally can result in suboptimal myocardial profusion and potential renal ischemia [Figure 18].
CARDIAC CONDUCTION DEVICES
Cardiac conduction devices are used in clinical practice for more than 6 decades. The most commonly used cardiac conduction devices are pacemaker and implantable cardioverter-defibrillator. These devices have three main parts; pulse generator, electrodes, and lead wires. The radiologist should check all of these parts and look for abnormalities in the course, coiling, and fracture.
Positioning of the cardiac conduction devices
The most commonly utilized insertion approach is by the percutaneous transvenous technique where the leads are inserted via the left subclavian vein for the right atrial access. The generator is placed in the subcutaneous pocket.
Malfunctioning/malpositioning of the cardiac conduction devices: The interpreting radiologist should look for kinking, pinching, and fracturing of the leads [Figure 19]. An extremely rare condition pacemaker-twiddler’s syndrome refers to permanent malfunction of a pacemaker which occurs when the patient manipulates the subcutaneous chest device resulting in retraction of the previously well-positioned AICD/pacer leads. The interpreting radiologist should also be watchful for the course of the pacemaker/AICD leads since rarely there may be presence of left-sided SVC which makes the implantation of cardiac pacing lead into the right ventricle particularly difficult. This occurs due to the ostium of coronary sinus not being in alignment with the tricuspid orifice and hence a loop must be made before the lead can pass through the tricuspid valve [Figure 20]. In routine clinical practice, the radiologist will come across abandoned AICD/pacer leads which were intentionally left. These abandoned catheters rarely cause complications.
A pneumothorax should be excluded on the immediate post-insertion chest radiograph.
Chest radiograph is routinely used to assess the appropriate positioning of support devices. An increased awareness of normal and incorrect positions of support devices on chest radiographs can prevent the development of adverse events.
Declaration of patient consentPatient’s consent not required as patients identity is not disclosed or compromised.
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Conflicts of interestThere are no conflicts of interest.
- (1st ed). Amsterdam: Elsevier; 2019. p. 618-30Problem Solving in Chest Imaging.
- ENDOTRACHEAL TUBE
- TRACHEOSTOMY TUBE
- ENTERIC TUBE
- ESOPHAGEAL TEMPERATURE PROBE
- CENTRAL VENOUS CATHETERS
- Positioning of central venous catheters
- Malpositioning and other complications of central venous catheters
- Key point
- PULMONARY ARTERIAL CATHETER
- Positioning of the Swan-Ganz catheter
- Malpositioning and complications of Swan-Ganz catheter
- Key point
- INTRA-AORTIC BALLOON PUMP
- CARDIAC CONDUCTION DEVICES