Searching for baseline blood pressure: A comparison of blood pressure at three different care points.

A common approach to blood pressure management in the operating room is to keep the intraoperative, pressures within 20% of baseline blood pressure. One question that arises from this recommendation is; what is a patient's true baseline blood pressure? In order to get a more precise definition of baseline blood pressure, a comparison of the first operating room blood pressure was made with the blood pressure taken in a preoperative holding area before surgery, and the blood pressure taken in pre-surgical testing. (before day of surgery). A database of 2087 adult general anesthesia cases was generated, which contained the blood pressure (BP) in the pre-surgical testing clinic, the first BP in preoperative holding on the day of surgery, and the first BP in the operating room. Comparisons were made between the blood pressures taken at each phase of care. All components of BP taken in the OR were statistically significantly higher (p<0.001 for all comparisons) than in either PST or the holding area, while the BP in the latter locations were not significantly different. This blood pressure difference persists whether or not the patient is taking antihypertensive medications. The higher blood pressure measured in the operating rooms precludes using this measurement to determine baseline blood pressure. Blood pressures taken prior to arrival in the operating room are similar to blood pressures taken before the day of surgery. Blood pressure measurements taken prior to entrance in the operating room can be used to determine baseline blood pressure.