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Background and Objectives: Postoperative cognitive dysfunction (POCD) is related to factors such as physical status, electrolytic, visual and immune disorders, alcoholism, drugs and advanced age. This study aimed at determining the prevalence of POCD and its associated factors., Methods: Participated in this prospective study 55 patients aged 18 to 89 years, scheduled for elective orthopedic, urologic, general or vascular surgeries, under general or regional anesthesia. The Mini-Mental State Examination (MMSE) was applied the day before surgery (M0), at 24 postoperative hours (M1) and 3 to 7 days after surgery (M2). POCD was defined as MMSE score below 24/30 or as a difference equal to or above 4 as compared to M0. Univariate and multivariate analysis variables included age, gender, type of anesthesia and surgery, intraoperative hypotension, hypoxemia or hypocapnia, use of atropine and surgery length., Results: POCD was observed in eight patients (14.54%). All POCD patients were above 65 years of age. Among these patients, the prevalence of POCD was 28.57%. Only age and preanesthetic MMSE scores were different between patients with or without POCD. The logistic model included only preanesthetic MMSE scores., Conclusions: Among the variables included in this study, only preanesthetic MMSE score is a significant independent predictor of POCD.

Background and Objectives: Minimum anesthetic volume (MAV) of local anesthetics corresponds to the effective volume for regional anesthesia in 50% of patients. In this study, MAV of 0.5% racemic bupivacaine, 0.5% levobupivacaine and enantiomeric S75/R25 bupivacaine were calculated and compared., Methods: This study involved two series of patients undergoing cataract extraction. Series 1 patients received either 0.5% racemic bupivacaine (n = 9) or 0.5% levobupivacaine (n = 11). Series 2 patients received either 0.5% racemic bupivacaine (n = 11) or 0.5% enantiomeric S75/R25 bupivacaine (n = 10). Blockades were achieved by single-injection and inferior-lateral approach. Motility of each rectus muscle was assessed 10 minutes later as: 0 (absent), 1 (decreased) or 2 (normal). Total muscle scores represented total eye motility score (TMS). Local anesthetic volume administered to the first patient of each group was 7.4 mL. Subsequent patients received volumes corresponding to 0.1 higher natural logarithm unit (if TME > 2) or lower (if TME < 2) as compared to natural logarithm of preceding volume. Massey and Dixon's formulae were used for MAV calculations., Results: MAVs of bupivacaine in both series were 6 mL and 6.2 mL, respectively. MAVs of levobupivacaine and enantiomeric S75/R25 bupivacaine were 5.7 mL and 5.8 mL, respectively. There were no differences between groups in effective anesthetic volumes., Conclusions: Similar volumes of 0.5% racemic bupivacaine, 0.5% levobupivacaine and enantiomeric S75/R25 bupivacaine are needed for extraconal retrobulbar anesthesia.

Background and Objectives: The benefits of adding hyaluronidase to local anesthetics for peribulbar blockade remain controversial. This study aimed at comparing the effects of hyaluronidase on the akinesia of rectis muscles, elevator muscle of upper eyelid and orbicular muscle of the eye after peribulbar blockade with 0.5% enantiomeric mixture of bupivacaine (S75-R25) and 2% lidocaine., Methods: Participated in this study 35 adult patients, who were distributed in group 1, receiving a 1:1 association of 0.5% enantiomeric mixture of bupivacaine (S75-R25) and 2% lidocaine plus epinephrine (5 microg.ml-1), and group 2, receiving the same anesthetic solution with hyaluronidase (50 UI.ml-1). Motility of rectis muscles, elevator muscle of upper eyelid and orbicular muscle of the eye was evaluated at 1, 5, 10 and 15 minutes after blockade., Results: Extraocular motility scores have significantly decreased during the observation period, without significant differences between groups. The percentage of patients with eyeball akinesia did not significantly differ between groups. Pain at local anesthetic injection site did not differ between groups. Surgical anesthesia was rated as satisfactory by all patients., Conclusions: This study could not show any effect of combining hyaluronidase (50 UI.ml-1) and the 1:1 association of 0.5% enantiomeric mixture of bupivacaine (S75-R25) and 2% lidocaine plus epinephrine (5 microg.ml-1) on the akinesia of rectis muscles, elevator muscle of upper eyelid and orbicular muscle of the eye.