Noninvasive blood pressure measurement.

Blood pressure measurement in the operating room has become increasingly sophisticated. The principles used, however, are based on proven concepts. The author's review of the historical bases for the principles, the principles themselves, and clinical applications demonstrate how anesthesiology has been improved by the development of different techniques for measuring blood pressure. Because the usefulness of the pressure readings--systolic, diastolic, or mean arterial--depends upon the clinical situation, all should be recorded. The automatic, noninvasive measuring devices offer substantial advantages in patient safety.