title: Intraocular Pressure Changes With Positioning During Laparoscopy.
abstract: OBJECTIVE
  Pneumoperitoneum during laparoscopy can produce changes in intraocular pressure (IOP) that may be influenced by several factors. In this study, we investigated changes in IOP during laparoscopy with different positioning.
  
  
  METHODS
  We recruited adult patients without eye disease scheduled to undergo laparoscopic operation requiring a reverse Trendelenburg tilt (rTr; group A; n = 20) or Trendelenburg tilt (Tr; Group B; n = 20). IOP was measured at 7 time points (T1-T7). All procedures were performed with standardized anaesthetic protocol. Mean arterial pressure (MAP), heart rate (HR), peak and plateau airway pressure, and end-tidal carbon dioxide (ETCO2) measurements were taken at each time point.
  
  
  RESULTS
  Both groups were similar in age, sex, mean body mass index (BMI), duration of surgery, and preoperative IOP. A decrease in IOP was observed in both groups after induction of anaesthesia (T2), whereas induction of pneumoperitoneum produced a mild increase in IOP (T3) in both groups. The Trendelenburg tilt produced IOP elevations in 80% of patients compared to 45% after the reverse Trendelenburg tilt (P= .012). A significant IOP increase of 5 mm Hg or more was recorded in 3 (15%) patients in the Trendelenburg tilt group and in none in the reverse Trendelenburg group. At T7, IOP had returned to preoperative levels in all but 3 (15%) in the Trendelenburg and 1 (5%) in the reverse Trendelenburg group. Reversible changes were observed in the MAP, HR, ETCO2, and airway pressures in both groups.
  
  
  CONCLUSIONS
  IOP changes induced by laparoscopy are realigned after evacuation of pneumoperitoneum. A Trendelenburg tilt however produced significant changes that may require careful patient monitoring during laparoscopic procedures.
authors.affiliation: Departments of Surgery.
authors.forename: Adewale O
authors.initials: AO
authors.lastname: Adisa
authors.affiliation: Ophthalmology.
authors.forename: Oluwatoyin H
authors.initials: OH
authors.lastname: Onakpoya
authors.affiliation: Anaesthesia and Intensive Care, Obafemi Awolowo University and Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria.
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Adenekan
authors.affiliation: Ophthalmology.
authors.forename: Oluwaseun O
authors.initials: OO
authors.lastname: Awe
mesh_terms: D034841:Abdominal Cavity / Q000503:physiopathology; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D010535:Laparoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D011028:Pneumoperitoneum, Artificial / Q000379:methods*; D011312:Pressure
keywords: Intraocular pressure; laparoscopy; position