Effects of Systemic Administration of Dexmedetomidine on Intraocular Pressure and Ocular Perfusion Pressure during Laparoscopic Surgery in a Steep Trendelenburg Position: Prospective, Randomized, Double-Blinded Study

Increased intraocular pressure (IOP) during surgery is a risk factor for postoperative ophthalmological complications. We assessed the efficacy of systemically infused dexmedetomidine in preventing the increase in IOP caused by a steep Trendelenburg position, and evaluated the influence of underlying hypertension on IOP during surgery. Sixty patients undergoing laparoscopic surgery in a steep Trendelenburg position were included. Patients in the dexmedetomidine group received a 1.0 µg/kg IV loading dose of dexmedetomidine before anesthesia, followed by an infusion of 0.5 µg/kg/hr throughout the operation. Patients in the saline group were infused with the same volume of normal saline. IOP and ocular perfusion pressure (OPP) were measured 16 times pre- and intraoperatively. In the saline group, IOP increased in the steep Trendelenburg position, and was 11.3 mmHg higher at the end of the time at the position compared with the baseline value (before anesthetic induction). This increase in IOP was attenuated in the dexmedetomidine group, for which IOP was only 4.2 mmHg higher (P < 0.001 vs. the saline group). The steep Trendelenburg position was associated with a decrease in OPP; the degree of decrease was comparable for both groups. In intragroup comparisons between patients with underlying hypertension and normotensive patients, the values of IOP at every time point were comparable. Dexmedetomidine infusion attenuated the increase in IOP during laparoscopic surgery in a steep Trendelenburg position, without further decreasing the OPP. Systemic hypertension did not seem to be associated with any additional increase in IOP during surgery. (Registration at the Clinical Research Information Service of Korea National Institute of Health ID: KCT0001482)

What do we take consideration in the patient who has an unpredicted severe portopulmonary hypertension in liver transplantation?: a case report / 대한마취과학회지

Severe portopulmonary hypertension (PPHT) is considered a contraindication for liver transplantation (LT) because of the associated high mortality and poor prognosis. We report the case of a 57-year-old cirrhotic woman with severe PPHT (mean pulmonary artery pressure [mPAP] > 65 mmHg), who underwent a successful living donor LT. Intra-operative use of inhaled iloprost, milrinone, dobutamine, and postoperative use of inhaled nitric oxide and oral sildenafil failed to lower the pulmonary artery pressure (PAP). The patient responded only to nitroglycerin and drainage of massive ascites. Meticulous intra-operative volume control, which included minimizing blood loss and subsequent transfusion, was carried out. The use of vasopressors, which may have elevated the PAP, was strictly restricted. Intra-operative PAP did not show an increase, and the hemodynamics was maintained within relatively normal range, compared to the preoperative state. The patient was discharged without any complications or related symptoms.