Arterial line

An arterial line (also called an arterial catheter or 'art line') is a thin, flexible tube inserted directly into an artery to provide continuous, real-time blood pressure monitoring and easy access for blood sampling. Unlike the intermittent readings given by a standard blood pressure cuff, an arterial line displays a beat-to-beat pressure waveform on the bedside monitor, allowing intensive care staff to detect even brief changes in blood pressure instantly. This level of precision is essential when managing patients on vasopressor drugs or undergoing complex titration of sedation and ventilation.In adults, the radial artery at the wrist is the most common insertion site because it is accessible, comfortable and has a good collateral blood supply from the ulnar artery should any problem arise. The femoral artery in the groin, brachial artery at the elbow and dorsalis pedis artery on the foot are alternative sites used when radial access is not possible. After cardiac arrest, arterial lines are placed routinely as part of post-resuscitation care in the intensive care unit, enabling close haemodynamic management during targeted temperature management (TTM) and the critical early hours of recovery.Blood samples taken from the arterial line are used for arterial blood gas (ABG) analysis, which measures oxygen levels, carbon dioxide levels, pH and lactate in the blood. These values guide decisions about mechanical ventilation settings, fluid therapy and the need for additional interventions. Arterial blood sampling avoids repeated venepuncture and the risk of venous samples being affected by arm position or tourniquet use.An arterial line is removed when the patient is stable enough that continuous monitoring is no longer required, typically when vasopressors have been weaned and the patient is able to breathe independently. The insertion site is dressed and monitored for bleeding, bruising or signs of infection. Most patients are unaware of the arterial line...