BRANFORD, Conn., June 22, 2010 (GLOBE NEWSWIRE) -- CAS Medical Systems, Inc. (Nasdaq:CASM) today announced that a new study published on-line in Anesthesia & Analgesia demonstrating the benefits associated with monitoring absolute cerebral oximetry using the FORE-SIGHT ® Absolute Oximeter on patients undergoing arthroscopic shoulder surgery 1.
The beach chair position has been used for shoulder arthroscopic procedures since the early 1980's and has gained popularity because it offers a number of technical advantages over the lateral decubitus approach 2,3. In the United States, approximately two-thirds of arthroscopic and open shoulder procedures are performed in the beach chair position and, although rare, catastrophic neurologic events such as brain and spinal cord injury, visual loss, and cerebrovascular events have been reported following surgery in this position 4,5,6,7. The Anesthesia Patient Safety Foundation (APSF) Newsletter (Winter 2009-2010) stated, "There have been increasing reports of severe neurological injury in previously healthy patients having surgery in head-above-heart positions (shoulder surgery in the beach chair position) but the incidence and mechanisms are unknown." 8
In a recent (Oct 2009) APSF workshop focused on the topic of cerebral perfusion pressure in the beach chair position, Dr. Robert K. Stoelting, President of the APSF, introduced the APSF's position statement regarding this issue: "The APSF believes that reports of global ischemic brain damage following surgical procedures in the semi-sitting "beach chair" position may reflect unrecognized cerebral hypoperfusion." 9 He also stated, "Patient safety may benefit from a discussion of acceptable cerebral perfusion pressures and methods to monitor the adequacy of cerebral blood flows." 9In response to the workshop, the APSF is funding the creation of the Neurologic Injury after Non-Supine Surgery Registry (NINS) to "collect and analyze adverse neurologic outcomes following shoulder arthroscopy surgery" 8 and is also offering research funding to further study problems associated with "unexpected neurocognitive deficits in patients undergoing general anesthesia during surgery in non-supine positions." 8 In this new independent study to be published in Anesthesia & Analgesia by researchers at the Department of Anesthesiology, NorthShore University HealthSystem, University of Chicago Pritzker School of Medicine, data was collected on 124 patients undergoing elective shoulder arthroscopy in two approximately equal sized groups. One group had surgery performed in the beach chair position (BCP), the second group had surgery performed in the lateral decubitus position (LDP). The results from the study showed that cerebral desaturation events occurred frequently in patients in the BCP, whereas there were no desaturation events observed in a similar group of patients undergoing surgery in the LDP. The study included an intervention protocol for clinicians when a cerebral desaturation event as measured by the FORE-SIGHT monitor occurred, thereby allowing clinicians to proactively treat the patients and reduce the duration of the event. The study also reported a strong correlation between cerebral desaturation events and a multi-fold increase in the incidence of post-operative nausea and vomiting.