80. Back to Basics: Arterial Lines

Arterial lines provide essential real-time, beat-to-beat blood pressure monitoring and facilitate frequent blood gas sampling in critically ill patients. While radial access remains the standard first-line approach due to its safety and ease of compression, clinicians should utilize ultrasound guidance to improve success rates and minimize complications. Beyond basic monitoring, arterial waveforms offer critical physiological insights, including the detection of pulsus paradoxus, pulsus alternans, and pulsus bisferiens, which can signal underlying cardiac pathologies like tamponade or aortic stenosis. Proper system maintenance, including zeroing, leveling, and performing square wave tests, is vital to ensure data accuracy. While arterial lines are powerful tools for managing hemodynamically unstable patients, they carry risks such as infection and hemorrhage, necessitating aggressive de-escalation once the clinical need for invasive monitoring subsides.