| Endotracheal tube | tip 5 ± 2 cm above the carina (neck neutral); roughly T2–T4 / medial clavicular ends; flexion moves the tip down, extension up | right main bronchus (left lung/RUL collapse, right hyperinflation), oesophageal intubation (gastric distension), too high (vocal cord injury, extubation) |
| Tracheostomy tube | tip at T3, about half to two‑thirds of the way from stoma to carina | pneumothorax, surgical emphysema |
| Nasogastric tube | descends in the midline, bisects the carina, crosses the diaphragm, tip > 10 cm into the stomach | bronchial placement (never feed), coiled in oesophagus, intracranial (basal skull fracture) |
| Central venous catheter | tip at the cavoatrial junction / lower SVC (≈ 2 vertebral bodies below the carina) | pneumothorax, arterial puncture, azygos or contralateral vein placement, haemothorax |
| PICC | lower SVC | malposition (IJV) |
| Chest drain | posterior‑superior for air, posterior‑inferior for fluid; side holes inside the pleura | subcutaneous, fissural, intraparenchymal, side hole outside the chest wall |
| Pacemaker / ICD | RA appendage and RV apex leads | lead fracture, displacement, twiddler syndrome |
| Intra‑aortic balloon pump | tip 2–4 cm below the top of the aortic arch (2nd ICS) | too high (cerebral emboli), too low (renal/mesenteric occlusion) |