CHANGES IN MEAN BLOOD-PRESSURE CAUSED BY DAMPING OF THE ARTERIAL-PRESSURE WAVE-FORM

'Damping' of an intra-arterial pressure waveform theoretically affects systolic and diastolic blood pressure whilst mean blood pressure (mbp ) continues to be reliable. We assessed changes in mbp associated with 79 episodes of damping in 30 infants. The average mbp in the hour jus t before damping occurred was compared with that in the first hour of damping. The mean change in mbp was -0.845 mmHg. In 50% of cases this change was < 2 mmHg and in 24% of episodes greater than or equal to 4. 1 mmHg. Damping may produce clinically significant changes in mbp whic h computer trend data may help to differentiate.