Evaluation of spinal cord blood flow during prostaglandin E1-induced hypotension with power Doppler ultrasonography.

STUDY DESIGN

Intraoperative power Doppler ultrasonography was used to evaluate the spinal cord blood flow in cervical spondylotic myelopathy patients during hypotensive anesthesia.

OBJECTIVE

To evaluate the effect of prostaglandin E1 (PGE1) induced hypotension on spinal cord blood flow (SBF) during spinal surgery.

SUMMARY AND BACKGROUND DATA

Hypotension is frequently induced to decrease blood loss during surgery and to diminish the need for blood transfusion. Prostaglandin E1 (PGE1) is reported to maintain cerebral, liver, and renal blood flow during surgery. However, there are few reports on spinal cord blood flow.

METHODS

Eleven patients underwent laminoplasty for cervical spondylotic myelopathy. After a French door type laminoplasty was carried out, hypotension was induced with PGE1. Before and during hypotension, we evaluated blood flow in the anterior spinal cord artery by determining the pulsatility index (PI) and resistance index (RI) using power Doppler ultrasonography.

RESULTS

Before hypotension, the mean blood pressure was 80 mmHg. The blood pressure decreased to 60 mmHg using PGE1 (P<0.01), although the PI and RI were significantly higher than before hypotension (PI, P=0.0076 RI, P=0.02).

CONCLUSION

The pulsatility and resistance indices during hypotension were significantly higher than before hypotension, suggesting that the autoregulation of the anterior spinal cord artery and anterior spinal cord blood flow were maintained with hypotension using PGE1. Prostaglandin E1 may be a useful drug for hypotensive anesthesia in spinal surgery.