Epidural analgesia and postoperative orthostatic haemodynamic changes: observational study.

Context: In thoracic and abdominal surgery, epidural analgesia provides excellent pain relief, but associated postural hypotension can delay mobilisation.
Objectives: To assess postoperative orthostatic haemodynamic changes in patients receiving epidural analgesia after major surgery.
Design: Prospective observational study. Physiological intervention.
Settings: Montreal General Hospital tertiary teaching hospital.
Patients or Other Participants: Patients scheduled for thoracic or abdominal surgery with thoracic epidural analgesia using a mixture of bupivacaine 0.1% and fentanyl 3 μg ml(-1).
Intervention(s): Arterial blood pressure and heart rate were measured in supine, sitting and standing position before surgery and daily for the first 3 postoperative days.
Main Outcome Measure: Orthostatic hypotension, defined as a drop in SBP of more than 20  mmHg during the orthostatic tests, was investigated as a predictor of inability to mobilise during the postoperative period.
Results: One hundred and sixty-one patients were enrolled in the study. Hypotension was detected in 59 (37%) of the patients on postoperative day 1, 20 (12%) on day 2 and four (2.5%) on day 3. On day 1, 43% of the patients walked, 39% only sat and 17% were bedridden. Supine SBP less than 90  mmHg, haemodynamic changes during the orthostatic tests, dizziness or nausea, did not predict inability to walk. Only blood loss more than 500  ml and supine mean BP less than 70  mmHg were negative predictors of mobilisation on day 1.
Conclusion: Epidural analgesia is associated with arterial hypotension in the postoperative period. However, haemodynamic assessment does not predict inability to walk after thoracic and abdominal surgery. Early mobilisation should be tried irrespective of BP or orthostatic changes in postoperative patients with epidural analgesia.