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Background and Objective: The constant equilibrium between the plasma and effect site (ke0) is used by pharmacokinetic models to calculate a drug concentration in its site of action (Ce). It would be interesting if Ce of propofol was similar at loss and recovery of consciousness. The objective of this study was to evaluate the clinical performance of two different ke0 (fast = 1.21 min(-1), and slow = 0.26 min(-1)) in relation to Ce during loss and recovery of consciousness using Marsh pharmacokinetic model., Methods: Twenty healthy adult male volunteers participated in this study. In all volunteers propofol was administered as target-controlled infusion, Marsh pharmacokinetic model for fast ke0 and, at a different time, the same pharmacokinetic model with slow ke0 was used. Initially, propofol was infused with a serum target-controlled infusion of 3.0 μg.mL(-1). Loss of consciousness and recovery of consciousness were based on response to verbal stimulus. Ce was recorded at the moment of loss and recovery of consciousness., Results: On loss and recovery of consciousness, the Ce for fast ke0 was different (3.64 ± 0.78 and 1.47 ± 0.29 μg.mL(-1), respectively, p < 0.0001), while with slow ke0 the Ce was similar (2.20 ± 0.70 and 2.14 ± 0.43 μg.mL(-1), respectively, p = 0.5425)., Conclusions: Clinically, the slow ke0 (0.26 min(-1)) incorporated in the Marsh pharmacokinetic model showed better performance than the fast ke0 (1.21 min(-1)), since the calculated concentration of propofol at the effect site on loss and recovery of consciousness was similar., (Copyright © 2011 Elsevier Editora Ltda. All rights reserved.)

Background and Objectives: Due to its pharmacokinetic characteristics, remifentanil does not promote residual analgesia in the immediate postoperative period. The objective of this study was to compare the efficacy of methadone and clonidine in the control of postoperative pain of videolaparoscopic surgeries under total intravenous anesthesia with target-controlled remifentanil infusion., Methods: One hundred and twenty-six patients, ages 18 to 65 years, ASA I and II, of both genders, scheduled for laparoscopic surgeries, participated in this randomized, double- blind, placebo-controlled study. After venipuncture, intravenous ketoprofen and dypirone were administered. Target-controlled infusion of remifentanil and propofol was used for induction and maintenance of anesthesia. Before beginning the procedure, an intravenous solution containing 0.1 mg.kg-1 of methadone (methadone group), 2.0 (1/4)g.kg-1 of clonidine (clonidine group), or NS (placebo group) was administered. In the post-anesthetic care unit, postoperative pain was evaluated by the Verbal Numeric Scale (VNS). Absence of pain was defined as a score < 2, and pain as a score of > 3., Results: The incidence of pain in the methadone group was significantly lower than in the clonidine and placebo groups (11, 21, and 23, respectively; p < 0.02). Significant differences in the incidence of pain in the placebo and clonidine groups were not observed., Conclusions: Methadone was more effective than clonidine in the control of postoperative pain in videolaparoscopic surgeries under total intravenous anesthesia with remifentanil; and using clonidine was not better than not using it.

Background and Objectives: Enantiomeric mixtures of bupivacaine in different formulations, S75-R25 or S90-R10, were proposed aiming at reducing the cardiotoxicity and with a satisfactory motor blockade. The aim of this study was to compare the length of time until the appearance of the motor blockade and its degree using 50% enantiomeric excess 0.5% bupivacaine (S75-R25), 0.5% racemic bupivacaine, and 2% lidocaine for facial nerve block by the O'Brien technique., Methods: Forty-five patients, over 60 years old, scheduled for the surgical treatment of cataracts under retrobulbar block preceded by O'Brien paralysis participated in this study. Patients were randomly divided in three groups of 15 patients, according to the anesthetic used for the facial nerve block: Group L (Lidocaine), Group B (Bupivacaine), and Group M (S75-R25). Three milliliters of the solution were administered. The length of time for motor blockade to become apparent and the degree of the motor block (Grades 1, 2, and 3) were evaluated 15 seconds after the injection and every 15 seconds until it reached 180 seconds., Results: The initial manifestations of the blockade were faster (15 s) in Group L. There were no differences between Groups B and M. Every patient in Group L showed Grade 3 motor block in up to 60 seconds, which was faster than Groups B and M (120 and 135 seconds, respectively). Groups B and M had similar behavior during the study, without any statistically significant difference. At 180 seconds, the incidence of Grade 3 motor block was similar in all three groups., Conclusions: The beginning of the motor blockade and its maximal degree were achieved faster with 2% lidocaine. The same degree was achieved by racemic bupivacaine and S75-R25, but it took longer. These two anesthetics showed the same behavior regarding the latency and the maximal degree of motor block, but at the end of 180 seconds there were no differences in the intensity of the blockade among the three groups.

Background and Objectives: There are reports on epidural blood patch in Jehovah's Witness patients using a closed system which allows blood collection and epidural injection without loss of continuity. This report aimed at presenting two cases of Jehovah's Witness patients with post-dural puncture headache and treated with epidural blood patch in a closed venous blood transfusion system to the epidural space. Cases were reported by two different hospitals in two different cities., Case Reports: One 21 years old male patient and one 32 years old female patient, with post-dural puncture headache after outpatient procedures. Since they were Jehovah's Witnesses, blood patch was performed with a closed system. System was prepared in sterile conditions using the following materials: two serum catheters cut in 60 cm segments, one two-way connection, one three-way tap and one 20 ml syringe. System was assembled to allow one connection to the puncture needle (20G), one connection to the three-way tap and the remaining two ways were connected to a 20 ml syringe and to the other serum catheter segment, which would be connected to the epidural needle. Lumbar region and right upper limb were disinfected with patients in the left lateral position. Epidural puncture was performed at L2-L3 interspace with 17G needle which was maintained fixed and connected to the serum catheter. Then, venous puncture was performed with a needle connected to the other edge of the serum catheter with the three-way tap directed from the vein to the syringe and 15 ml blood were aspirated. Redirecting the tap from the syringe to the epidural needle, the same 15 ml blood were re-injected., Conclusions: In Jehovah's Witness patients refractory to clinical treatment, autologous blood injection may be performed through the above-described technique after patients informed consent.

Background and Objectives: Complications of pregnant patients with medullary injury include urinary infection, renal stones, anemia, decubitus ulcers, muscle spasms, sepsis, uterine hyperactivity and autonomic hyperreflexia. Autonomic hyperreflexia is the most severe anesthetic complication and should, before all, be prevented. It is often developed in patients with medullary transection at the level of the 5th to 7th thoracic vertebra or above. This report aims at presenting a case of tetraplegic pregnant patient with injury at the level of the 6th cervical vertebra, submitted to Cesarean section under continuous epidural anesthesia with 0.25% bupivacaine without vasoconstrictor associated to fentanyl., Case Report: Caucasian, tetraplegic primiparous term patient, 39 weeks of gestational age, 22 years old, 63 kg, 168 cm, physical status ASA II, admitted for elective Cesarean section. Patient reported spinomedullary trauma at C6, three years ago. After previous hydration with 1500 ml saline, epidural anesthesia was induced with medial puncture at L3-L4 interspace with the patient in the lateral position, disposable 17G Tuohy needle and without previous local infiltration anesthesia. Immediately after needle insertion, there was adjacent paravertebral muscles contraction, blood pressure increase (BP = 158 x 72 mmHg) and heart rate increase (HR = 90 bpm). Patient, however, did not refer pain. Needle was removed and local anesthesia was induced. Epidural block proceeded with 20 ml of 0.25% bupivacaine without vasoconstrictor associated to 100 microg spinal fentanyl and epidural catheter insertion in the cephalad direction (3 to 4 cm). Surgery went on without intercurrences with no need for blockade complementation. There were two arterial hypotension episodes in the first 24 postoperative hours, which were treated with lactated Ringers solution. Epidural catheter was maintained for 48 hours. Patient was discharged three days after., Conclusions: For paraplegic or tetraplegic pregnant patients, continuous epidural anesthesia with low local anesthetic concentration without vasoconstrictor and associated to fentanyl is a good indication for instrumented or not vaginal delivery, and Cesarean sections to prevent autonomic hyperreflexia. It is also important that the epidural catheter remains for at least 24 hours after delivery to block sympathetic afference in case a crisis is triggered.