ACCURACY OF DISPOSABLE BLOOD-PRESSURE TRANSDUCERS USED IN THE CRITICAL CARE SETTING

Objectives: To assess the initial accuracy, drift in calibration over several hours, and decline in accuracy over daily use of blood pressure transducers used in the critical care setting. Design: Prospective, criterion standard. Setting: Three critical care units in a university hospital. Subjects: Twenty-seven consecutively available high-pressure transducers were used to measure intra-arterial blood pressures, and 11 consecutively available low-pressure transducers were used to measure central venous and pulmonary arterial blood pressures. Interventions: High-pressure transducers were compared with a mercury column manometer, and low-pressure transducers were compared with a water column manometer at three pressure levels. Data were collected initially after installation of the pressure transducer, at 3 hrs, and at 6 hrs. Data collections were repeated on subsequent days. Measurements and Main Results: a) The majority of pressure transducers are accurate; b) there is no drift in the accuracy of pressure transducers over several hours; c) the accuracy of pressure transducers does not decline over subsequent days. Some transducers overestimated standard pressures by 10 mm Hg and/or underestimated standard pressure by 17 mm Hg. Conclusions: The majority of pressure transducers used in the critical care setting are accurate, although there are some transducers that may compromise patient care. Blood pressure transducers should be checked against a standard manometer upon installation, and daily during use.