Fig. 3.
Postoperative hypotension. Blood pressure was recorded at 1-min intervals during the initial 48 h in adults recovering from abdominal surgery using a noninvasive monitoring system. The figure shows continuous hypotensive episodes of various durations under various thresholds. For each patient, the total time of the observed longest continuous hypotensive episode with mean arterial blood pressure (MAP) readings below various thresholds was computed. The percent of patients with at least that many minutes below the threshold is plotted. For example, the green line shows that 24% of patients had a continuous episode of MAP less than 70 mmHg lasting at least 30 min. Only about half of these episodes were identified by routine vital sign assessments at 4-h intervals. With permission from Turan et al.15