Reference — Labs & Diagnostics
Chest X-Ray: Tube & Line Placement Quick Reference
Where each tube and line should sit on a chest radiograph — and the malposition signs respiratory therapists must catch before the device is used.
Written by Apex Respiratory Editorial Team
Educational use only. This material supports respiratory therapy education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional protocols, or physician orders. Always follow facility policies and current provider orders, and verify calculations independently before clinical use.
Overview
The post-procedure chest film is the respiratory therapist’s confirmation that a tube or line landed where it belongs — and the first chance to catch a dangerous malposition before it causes harm. Read every device against a known anatomic landmark: the carina for airway and central-venous devices, the diaphragm for gastric tubes, and the inner rib margin for chest tubes. The notes below pair the correct radiographic position for each device with the malposition signs to flag, but the film confirms rather than replaces the bedside exam — always correlate with breath sounds, capnography, and the procedure note.
Tube & Line Placement on Chest Radiograph
| Device | Correct position on CXR | Malposition signs |
|---|---|---|
| Endotracheal tube (ETT) | Tip ~3–5 cm above the carina with the head in neutral (mid-trachea, roughly at the level of the aortic arch / T4–T5). The tip moves ~2 cm with the neck — flexion advances it toward the carina, extension withdraws it toward the cords. | Too low = right mainstem intubation (right-lung overinflation, left collapse/atelectasis, absent left breath sounds). Too high = risk of inadvertent extubation or vocal-cord injury. |
| Tracheostomy tube | Tube centered within the airway lumen with its tip above the carina, roughly one-half to two-thirds of the way down the trachea. | Tip abutting the tracheal wall, a tube that is too long (tip near the carina), or one that is too short (risk of decannulation or false passage). |
| Central venous catheter (CVC) | Tip in the lower superior vena cava at the cavoatrial junction (about the level of the carina), parallel to the SVC wall. | Tip in the right atrium or ventricle, looping up the internal jugular, or crossing midline. After subclavian or IJ insertion, check the film for a pneumothorax. |
| PICC line | Tip in the lower SVC at the cavoatrial junction — the same target as a centrally inserted CVC. | Same malpositions as a CVC (high in the SVC, up the IJ, across midline); a tip advanced too deep into the right atrium can provoke arrhythmia. |
| Nasogastric / orogastric tube | Tube descends in the midline, bisects the carina, crosses the diaphragm, and ends with its tip below the diaphragm in the stomach. | Tip coiled in the esophagus, deviated into a bronchus or lung (airway misplacement — do NOT feed), or sitting above the gastroesophageal junction. |
| Chest tube | Side holes and the radiopaque sentinel-eye marker lie inside the pleural space, medial to the inner rib margin — apical-anterior for a pneumothorax, basal-posterior for an effusion. | Last (most proximal) side hole outside the pleural space, a kinked tube, or subcutaneous or interfissural placement. |
Clinical Notes
- Confirm ETT depth on every post-intubation and post-repositioning film, and correlate the radiographic tip position with bilateral breath sounds and continuous capnography.
- A nasogastric or feeding tube must be radiographically confirmed below the diaphragm in the stomach before anything is instilled — an airway-misplaced tube can be fatal if fed.
- Always look for a post-procedure pneumothorax after central-line insertion (subclavian or IJ) and after chest-tube placement.
- Remember the neck effect on the ETT: flexion advances the tip toward the carina and extension withdraws it, so re-read the film whenever head position has changed.
- The film confirms position but does not replace the bedside exam — treat a discrepancy between the radiograph and the clinical assessment as a reason to reassess, not to ignore.
Related Resources
Sources
- Kacmarek RM, Stoller JK, Heuer AJ. Egan's Fundamentals of Respiratory Care. 12th ed. Elsevier; 2021. Chest imaging; verifying tube and catheter position.
- National Board for Respiratory Care. Therapist Multiple-Choice Examination Detailed Content Outline. NBRC; 2024. Patient data evaluation: imaging studies.