The American Society of Anesthesiologists has published a recent Practice Advisory pertaining to postoperative visual loss associated with spinal surgery. The purpose of the advisory is to increase awareness of permanent impairment and/or total loss of sight associated with spinal surgery performed under general anesthesia. Anterior ischemic optic neuropathy, posterior ischemic optic neuropathy, and central retinal artery occlusion are all discussed in this practice advisory, which is available on-line at www.asahq.org and has also been published in the June 2006 issue of Anesthesiology. The advisory is a report produced by the American Society of Anesthesiologists Task Force on Perioperative Blindness and was approved by the ASA House of Delegates on October 25, 2005. Primary findings of the task force are summarized as follows:
“There is a subset of patients who undergo spine procedures while they are positioned prone and receiving general anesthesia that has an increased risk for developing perioperative visual loss. This subset includes patients who are anticipated preoperatively to undergo procedures that are prolonged, have substantial blood loss, or both (high risk patients).”
“Consider informing high-risk patients that there is a small, unpredictable risk of perioperative visual loss.”
“The use of deliberate hypotensive techniques during spine surgery has not been shown to be associated with the development of perioperative visual loss.”
“Colloids should be used along with crystalloids to maintain intravascular volume in patients who have substantial blood loss.”
“At this time there is no apparent transfusion threshold that would eliminate the risk of perioperative visual loss related to anemia.”
“High-risk patients should be positioned so that their heads are level with or higher than the heart when possible. In addition, their heads should be maintained in a neutral forward position (e.g., without significant neck flexion, extension, lateral flexion, or rotation) when possible.”
“Consideration should be given to the use of staged spine procedures in high-risk patients.”
Readers are encouraged to read the full document for detailed information on this important advisory, which includes specific information regarding the methodology, application, sources and strength of evidence, and limitations of this practice advisory.
Dr. Morell is the editor of this newsletter, Clinical Associate Professor of Anesthesiology, Wake Forest University Health Sciences, Winston-Salem, NC, and Adjunct Clinical Associate Professor of Anesthesiology, University of Florida School of Medicine, Gainesville, FL. Dr. Morell is in the private practice of anesthesiology and resides in Niceville, FL.