When is arterial line placement indicated?

• A. For Continuous Blood Pressure Monitoring And Frequent Arterial Blood Gas Sampling In Major Surgery Or Unstable Hemodynamics.
• B. For All Minor Outpatient Surgeries.
• C. Only When Central Venous Catheter Is Contraindicated.
• D. For Routine Preoperative Assessment.

Answer: (A)

The key idea is that an arterial line is used when you need continuous, beat-to-beat arterial blood pressure monitoring and you must obtain arterial blood gas samples frequently. This is most appropriate in major surgery or in patients with unstable hemodynamics, where small changes in pressure or gas status can guide urgent management and ventilator settings. An arterial line lets you monitor BP continuously and draw ABGs quickly without repeated needle sticks, which is crucial in unstable or critically ill patients.

This isn’t typically needed for minor outpatient surgeries, where noninvasive blood pressure measurement and less frequent labs suffice. It isn’t reserved only for situations where a central venous catheter is contraindicated, since arterial access serves a different purpose from central venous access. And it isn’t used for routine preoperative assessment, which aims to evaluate overall risk rather than provide continuous invasive monitoring.