Effectiveness of the Molloy Bridgeport Observation Scale in Predicting Increased Intraocular Pressure during da Vinci Robotic Procedures

Effectiveness of the Molloy Bridgeport Observation Scale (MBOS) in Predicting

Increased Intraocular Pressure During Da vinci Robotic Procedures

LaDean J. Livingston, RN, BSN, MS, CRNA, Jackson, Mississippi

Anne W.  Alexandrov, PhD, RN, CCRN, NVRN-BC, ANVP-BC, FAAN

The University of Alabama at Birmingham School of Nursing

Background and purpose:   Postoperative vision loss (POVL) has been associated with increased intraocular pressure (IOP) resulting in decreased retinal perfusion during 15-30^o Trendelenburg positioning for abdominal da Vinci robotic procedures.  The Molloy Bridge Observation Scale (MBOS) has been suggested as a method for anesthesia providers to recognize the signs of increased IOP without use of an expensive tonometry unit; however, the generalizability of this method has not been studied in a large number of centers.  Therefore, we aim to assess the comparative effectiveness of the MBOS in relation to tonometry readings to determine the presence of increased IOP.

Methods/Purpose:  Institutional Review Board approval is underway for the conduct of a prospective observational study that will serially compare use of the MBOS to actual tonometry readings in patients undergoing abdominal surgery using the da Vinci robot.  Consecutive cases will be enrolled that meet the following inclusion criteria:  Age > 19 years, and elective abdominal surgery using the da Vinci robot.  Subjects with a history of glaucoma will be excluded.  Concurrent measures will be taken by two investigators blinded to each other’s findings, with one performing an assessment using the MBOS and the principal investigator measuring actual tonometry pressures every 30 minutes for the duration of Trendelenberg positioning.  A surgical “time out” will occur with the patient returned to 0^o HOB elevation, if IOP exceeds 40 mm Hg.  This is a documented measure at which blood flow to the ocular nerve has ceased, potentially causing ischemic nerve damage.  Data will be entered/analyzed in SPSS.

Results:  This study is awaiting IRB approval with an anticipated start date of Summer2014.

Conclusion:  While use of the da Vinci robot has revolutionized the approach to a number of surgical procedures, increased IOP is an unfortunate associated finding.  This study will allow for comparative assessment of the effectiveness of 2 approaches that aim to reduce the risk of POVL in this patient population.   

Contact Information:  llivingston@umc.edu, ladeanjohnson@earthlink.net