Identify Need for Arterial Pressure Monitoring
Continuous arterial pressure monitoring is indicated for patients requiring BP monitoring >q1h, receiving continuous IV infusion of medications that affect cardiac output/blood pressure, requiring frequent blood gas monitoring or who are hemodynamically/neurologically unstable.
Arterial lines with continuous MAP monitoring is also required for patients with Intracranial Pressure Monitoring in order to continuously identify Cerebral Perfusion Pressure.
Prior to recording hemodynamic values, evaluate pressure waveforms, verify transducer levels, and ensure that sufficient flush volume and pressure is present.
When comparing NIBP to arterial line pressures, MBP provides the most appropriate comparison. Compare cuff to NIBP pressures taken from the same limb.
See Standard for Arterial Line Monitoring.
Cuff BP measurements become increasing less accurate when hypotension develops. Accuracy is also affected by user technique and cuff size. Insertion of an arterial line is easiest when a patient has an adequate BP. Continuous infusion of vasoactive drugs necessitates continuous BP monitoring to evaluate response to drug therapy and to identify adverse effects (see policy for deferred arterial line placement).
NIBP cuffs do not provide continuous pressure monitoring. Although more accurate than auscultative BP monitoring, NIBP cuffs can become inaccurate when peripheral circulation is compromised. NIBP cuffs are uncomfortable and can produce bruising in susceptible patients; they are not appropriate when >q1h BP monitoring is required. Repetitive inflation of a BP cuff can lead to false readings.
Systolic BP readings obtained from invasive arterial catheters are often accentuated, with reduced diastolic readings. NIBP measurements utilize different technology and may produce systolic readings that do not match the arterial line systolic reading. When correlating BP values, compare the mean readings, readings from the same limb and readings that are simulataneous. MBP from arterial lines and NIBP circuits provide more appropriate correlation.
Patients may have differing BPs between left and right limbs, and peripheral circulation may be reduced in shock.
Arterial pressures may be falsely elevated if an artery is in spasm. This can occur following repeated insertion attempts. A warm towel wrapped around the site may help to reduce spas