This months issue if Anesthesiology highlights a serious complication of surgery we all hope to never face…post operative visual loss (povl). This dreaded outcome is most commonly seen in prolonged prone cases but up till now it was unclear what the exact mechanisms or risk factors were. Dr. Lori Lee at UW in Seattle and a multi-center group published the largest study to date regarding povl:
In a case-control examination of 80 patients with ION compared with 315 matched control subjects, independent risk factors were:
- Male sex
- Wilson frame use
- Longer anesthetic duration
- Greater estimated blood loss
- Lower percent colloid administration
I have always suspected the Wilson frame was not our friend but had no idea of the relationship with povl. The other variables in our control would be blood loss and colloid. Intraoperative hypotension was noticeably missing from the risk factor list. As I read it the best anesthetic plan for these cases would be for intraoperative hypotension with a higher colloid utilization over crystalloid performed on the Jackson table. Comments?
Editorial by Dr Mark Warner here.