# Central Venous Access and Complications > Central venous access and complications for NEET-PG Medicine, covering site selection, ultrasound guidance, pneumothorax, tip position and line infection. - Canonical URL: https://prepelephant.com/topics/neet-pg/medicine/central-venous-access-and-complications - Exam / course: NEET-PG · Subject: Medicine - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-14 - Last updated: 2026-10-14 - Reference basis: Oxford Handbook of Critical Care; Bailey and Love's Short Practice of Surgery; Harrison's Principles of Internal Medicine - How to cite: "Central Venous Access and Complications", PrepElephant, https://prepelephant.com/topics/neet-pg/medicine/central-venous-access-and-complications ## Direct answer Central venous access places a catheter in a large central vein, most often the internal jugular, subclavian or femoral vein, for infusions, monitoring or critical care. The right internal jugular vein is usually preferred under real-time ultrasound guidance, and a chest X-ray confirms that the tip lies at the cavo-atrial junction. Infection, pneumothorax, arterial puncture and air embolism are the complications examiners expect you to prevent and recognise. ## What you must remember - **Right internal jugular:** the preferred site because its course to the superior vena cava is straight, with a lower pneumothorax risk than the subclavian approach. - **Subclavian:** a leading cause of pneumothorax and later subclavian stenosis, which matters for future dialysis access in the same arm. - **Femoral:** the option in emergencies or when the chest is unsafe, carrying the highest infection and thrombosis risk, so it should be replaced early. - **Tip position:** the lower superior vena cava at the cavo-atrial junction, because a tip in the right atrium raises the risk of arrhythmia. - **Arterial puncture:** the carotid artery lies medial to the internal jugular vein, so pulsatile bright red blood signals arterial access. - **Air embolism:** a sudden breathlessness with a mill-wheel murmur, prevented by the head-down position and sealed hubs. - **Infection prevention:** the bloodstream infection bundle includes hand hygiene, full barrier precautions, chlorhexidine-alcohol skin antisepsis and early removal of unneeded lines. - **Guidewire rule:** the guidewire must never be left unattended or released, since it can embolise into the circulation. ## A stepwise insertion under ultrasound guidance A patient in septic shock needs a central line for noradrenaline and reliable access, and the team must choose the site and avoid avoidable errors. The sequence below is a standard way to insert the line safely. 1. **Choose the site and check the vein:** Use ultrasound to confirm a patent, compressible internal jugular vein lateral to the carotid artery. Check coagulation and platelet count, and correct them if bleeding risk is significant. 2. **Prepare the sterile field:** Perform hand hygiene, wear full barrier precautions and apply chlorhexidine-alcohol to the skin, allowing it to dry. A checklist-based insertion is the standard way to reduce bloodstream infection. 3. **Position the patient:** Place the patient supine with a head-down tilt, which raises venous pressure and reduces the risk of air entering the vein. 4. **Cannulate under real-time vision:** Advance the needle into the vein, aspirate non-pulsatile dark blood, and pass the guidewire. The guidewire must stay in control at all times. 5. **Insert and secure the catheter:** Remove the needle, thread the catheter over the guidewire, flush each lumen and secure the line with a sterile dressing. 6. **Confirm position and check for complications:** A chest X-ray confirms the tip at the cavo-atrial junction and excludes pneumothorax and haemothorax. New arrhythmia during insertion suggests a tip in the right atrium or ventricle, which needs immediate correction. ## Where the examiner sets the traps Central line questions test whether you match each complication to its site and its prevention step. - **Trap:** choosing the left internal jugular for a routine line — **Correct:** the right side offers a straighter course to the superior vena cava, whereas the left route is longer and carries a theoretical risk to the thoracic duct. - **Trap:** treating femoral access as the default in an unstable patient — **Correct:** femoral lines carry the highest infection and thrombosis risk, so they are a temporary emergency option rather than a long-term choice. - **Trap:** assuming pneumothorax is the only complication of central access — **Correct:** arterial puncture, air embolism, arrhythmia, malposition and line infection are equally testable, and each needs its own prevention step. ## Frequently asked questions ### Which central venous site is preferred in the emergency department? The right internal jugular vein is generally preferred for central venous access in the emergency department, under real-time ultrasound guidance. Its straight course to the superior vena cava gives a good success rate, while femoral access is reserved for situations where the chest approach is unsafe. ### What is the correct tip position for a central venous catheter? The correct tip position for a central venous catheter is the lower superior vena cava at the cavo-atrial junction, confirmed on chest X-ray. A tip lodged in the right atrium or ventricle raises the risk of arrhythmia and perforation and must be repositioned. ### How is central line-associated bloodstream infection prevented? Prevention of central line-associated bloodstream infection relies on a bundle that includes hand hygiene, full barrier precautions, chlorhexidine-alcohol skin antisepsis and early removal of lines that are no longer needed. Insertion checklists and avoiding the femoral site where possible reduce the risk further. ### What should you do if air embolism occurs during central line insertion? If air embolism occurs during central line insertion, stop the procedure at once, place the patient in the left lateral position with the head down and give high-flow oxygen. A mill-wheel murmur and sudden breathlessness are the classic signs of venous air embolism.