Central venous access and its complications
Stem
A 71-year-old man, 76 kg, with a perforated sigmoid diverticulum and septic shock, is coming for emergency laparotomy. He is intubated in the ICU, on norepinephrine through two peripheral 20-gauge cannulas, with a mean pressure of 62 mmHg. Platelets are 140,000 and INR 1.3. You decide he needs a central line before incision.
Question
How do you place it, and how do you make it safe?
Ideal answer
HeadlineHe needs central access for vasopressors: right internal jugular under real-time ultrasound, and since blood color lies in shock, I confirm the vein before dilating.
- Right internal jugular, ultrasound throughout: larger and straighter to the vena cava; ultrasound raises success and lowers complications.1
- Full barrier, chlorhexidine allowed to dry, head down, to fill the vein and prevent air entry.
- Confirm venous placement before dilating: wire in the vein on ultrasound, or manometry or a venous waveform from the needle or a small catheter;1 at his pressure on oxygen, color and pulsatility tell me nothing.
- Wire only 10–15 cm, watching the ECG for ectopy;1 every hub kept closed.
- Tip in the superior vena cava near the atrial junction, and pneumothorax excluded, by chest radiograph or ultrasound.1
Watch for: pneumothorax, arterial injury, air embolism, arrhythmia now; infection and thrombosis later.
Breaking down the answer
- Site — subclavian has the lowest infection rate but more bleeding and pneumothorax, and is incompressible under the clavicle, so not in coagulopathy;2 femoral avoids the chest but infects more, and drugs given through it during CPR may not circulate above the diaphragm.3
- Ultrasound — the ASA guideline recommends it for the internal jugular; it shows the artery, a thrombosed vein and the overlap that makes a through-and-through puncture likely. The examiner is checking that I practice the way the guideline describes.
- Why confirm before dilating — dilating an artery is the harm I am preventing; color and pulsatility are unreliable in a hypotensive or hypoxemic patient.
- Wire depth and ectopy — ectopy means the wire is in the heart and I withdraw it until it stops.1 A pre-existing left bundle branch block matters, because a wire in the right ventricle can cause complete heart block.1
- Air — a spontaneously breathing patient entrains air through an open needle; lines come out head down, occlusive dressing on. Changes if end-tidal CO2 and pressure fall with an open hub: 100% oxygen, close it, left-side-down head-down, aspirate through the catheter.1
- Tip position — above the pericardial reflection, roughly at the carina on the radiograph, because a tip in the atrium can erode the wall and cause tamponade.
- Infection bundle — hand hygiene, maximal barrier, a chlorhexidine dressing, femoral avoided when possible, and prompt removal.1
Follow-up question
The line is in, but the transduced waveform is arterial at 110/60 and the blood from the port is pulsatile. A 7 French catheter is in the carotid. What do you do?
Follow-up answer
HeadlineA 7 French catheter in the carotid: I do not pull it. I tell the surgeon and call vascular surgery.
The catheter stays in place1 and he stays off anticoagulation while we plan; removal with compression risks hematoma, airway compression, stroke and pseudoaneurysm, so the vascular team removes it with open or endovascular repair. Meanwhile I get venous access at another site, preferably the other internal jugular under ultrasound or a femoral vein, so the laparotomy is not delayed. I check his neurologic status as soon as I can, reassess the neck for an expanding hematoma that would threaten the airway, document the event, and disclose it to the family and to him when he is awake.
Pitfalls that cost points
- Forgetting pneumothorax when an intraoperative patient becomes hypotensive after a subclavian attempt.
- Leaving a femoral line in for convenience after the case.
Rapid-fire
Q: Why does needle-in-artery matter less than dilator-in-artery? A: A thin needle hole seals with compression; a 7–9 French dilator tear does not and needs surgical repair.
Q: Why do you ask about a left-sided line? A: The left internal jugular crosses the brachiocephalic vein at an angle, has a higher perforation risk, and the thoracic duct sits on the left.
Q: How does ultrasound help confirm the tip? A: Agitated saline flushed through the catheter appears in the right atrium within about 2 seconds on a subcostal view.
Q: Why can a CVP be normal in a hypovolemic patient? A: CVP is a pressure, not a volume, and venoconstriction and positive pressure raise it; trends and dynamic indices are more useful.
Numbers to know
| Item | Value |
|---|---|
| Insertion depth, right IJ | ~15–16 cm |
| Insertion depth, left IJ | ~18–20 cm |
| Insertion depth, right subclavian | ~15 cm (left 16–17 cm)2 |
| Pneumothorax, all central lines | ~1%, highest with subclavian3 |
| Tip position | Cavoatrial junction, at or just above the carina on the radiograph |
Links
- Pulmonary artery catheter: indications, waveforms, complications, Pneumothorax and tension pneumothorax, Venous air embolism and the sitting position, Cardiac tamponade, including post-cardiac surgery, Sepsis and septic shock
- Atlas: Vascular access: IJ, femoral, radial, cubital fossa
- ASA Practice Guidelines for Central Venous Access (2020)
Sources
- 1.How To Do Internal Jugular Vein Cannulation, Ultrasound-Guided · Merck Manual Professional Edition, 2026 · merckmanuals.com
- 2.How To Do Infraclavicular Subclavian Vein Cannulation · Merck Manual Professional Edition, 2026 · merckmanuals.com
- 3.Vascular Access · Merck Manual Professional Edition, 2025 · merckmanuals.comASA 2020 central venous access practice guideline was not reachable from the fetcher; claims here are checked against these procedural references.
Facts on this page were checked against these sources on Oct 14, 2026. Guidelines change; confirm doses against current institutional protocols.