Charles Watson, Bonnie Molloy
Bridgeport Hospital of the Yale New Haven Network, USA
Background: Following a case of postoperative visual loss (POVL) in the steep Trendelenburg (ST) position at our institution, IOP measurements were taken during laparoscopic surgery. IOP was observed to rise overtime with increases (4-5 times baseline). While monitoring we observed eyelid edema, conjunctival edema (chemosis), ecchymosis, and facial edema and hypothesized that findings were correlated to rising IOP. We trialed apreventive supine intervention that significantly impacted increase in IOP and may potentially preventfuture (POVL) events since current literature cites retinal cell ganglion dysfunction as a result of evenbrief acute increases in IOP. Additionally, increased peri-orbital swelling and venous congestion secondary to trabecular meshwork dysregulated pressure dependent outflow may produce a low perfusion state in the eye, via a compartment syndrome mechanism. CosoptTM (Timolol/Dorzolamide) eye drops were trialed since this drug has dual action as a carbonic anhydrase inhibitor and a beta adrenergic blocker. Prevention ofIOP rising above 40 mmHg was the goal in these studies since 45-55 mmHg IOP was determined to be a critical threshold in POVL incidents. The aim was to provide an observation scale that enables theanesthesia caregiver to gage timing of intervention so as to prevent increases in IOP. Cosopt trial analysis showed statistical significance in comparison to ST group. Findings of eyelid edema correlated to a 2.5 times increase inbaseline IOP. Findings of chemosis correlated to a 3.4 times increase. An additional study site was used to generalize and validate initial findings and to increase sample size.
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