Anesthesia and analgesia
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Anesthesia and analgesia · Oct 2003
Randomized Controlled Trial Clinical TrialSevoflurane requirements to suppress responses to transcutaneous electrical stimulation during epidural anesthesia with 0.5% and 1% lidocaine.
We sought to determine general anesthetic requirements to suppress skin vasomotor reflex (SVmR) and pupillary dilation (PD) in response to transcutaneous electrical stimulation (TES) during combined epidural-general anesthesia. Thirty-five patients undergoing lower abdominal surgery were randomly divided into 2 groups to epidurally receive 0.5% (Group 1) or 1% lidocaine (Group 2) with sevoflurane anesthesia. A bolus injection of either lidocaine was followed by the infusion of the same solution, and the central dermatomal level of loss of cold sensation (C) was determined. After the induction of general anesthesia with 5% sevoflurane and 67% nitrous oxide, nitrous oxide was discontinued, and sevoflurane concentration was decreased. TES was given at both site C and site three dermatomal segments (U) cephalad to C to determine the end-tidal sevoflurane concentration required to suppress SVmR and PD. End-tidal sevoflurane concentration that suppressed both responses was larger in Group 1 than in Group 2 at both sites and was larger at site U than at site C in both groups. We conclude that sevoflurane requirements to suppress SVmR and PD in response to TES during combined epidural-general anesthesia are different depending on the concentration of lidocaine and the site where surgical stimulation is applied. ⋯ We evaluated sevoflurane requirements to suppress skin vasomotor reflex and pupillary dilation in response to a transcutaneous electrical stimulation at the surgical site during combined epidural-general anesthesia. Our results indicate that when epidural anesthesia is combined, general anesthetic requirements decrease depending on the lidocaine concentration for epidural anesthesia and the site where surgical stimulation is applied.
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Anesthesia and analgesia · Oct 2003
Case ReportsAnesthetic management for a five-day separation of craniopagus twins.
Craniopagus twinning is a rare form of the already uncommon entity of conjoint twins. With advances in medical technology and expertise, future attempts at surgical separation of these increasingly complex cases are likely to occur. Despite this, medical literature on the anesthetic management of these cases is sparse. The following case report details the anesthetic management and planning leading to and including the 5-dy separation of 11-mo-old craniopagus twins. The report emphasizes the importance of teamwork, communication, and advanced planning required in cases such as this. ⋯ The following case report documents the anesthetic planning and management leading to and including a 5-day separation of twins joined at the head. This case report also details the difficulties encountered during the unique combination of a rarely performed procedure and a long operating time.
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Anesthesia and analgesia · Oct 2003
Comparative StudyA laboratory evaluation of the level 1 rapid infuser (H1025) and the Belmont instrument fluid management system (FMS 2000) for rapid transfusion.
In this investigation I compared the heating capabilities, infusion rates, and air management system of the new FMS 2000 and the Level 1 infusion systems. A rollerhead pump was placed at the position of the IV bag spikes on the Level 1 disposable set and used to match the flow of the rollerhead pump of the FMS 2000. Infusate temperature was measured at 250 and 500 mL/min by using packed red blood cells (PRBC) at the infusate supply and distal end of the disposable tubing. Tubing lengths were equal for both systems. Devices were set at maximum flow while temperatures were measured as described previously. Flow was measured with a graduated cylinder and stopwatch. Air management was evaluated with a 10-mL air bolus injected proximal to the heat exchanger at maximum flow. Air passing through the system was collected and measured. At 250 mL/min, both devices provided infusate at >or=37 degrees C. At 500 mL/min, only the FMS 2000 provided PRBC at >or=37 degrees C. PRBC infusate temperature decreased over time with the Level 1 device. The FMS 2000 delivered PRBC at its maximum flow rate of 500 mL/min. The Level 1 attained a maximum flow of 575 mL/min of PRBC with a temperature of 32 degrees C. Air (10 mL) was recovered from the distal tubing of the Level 1. No air was recovered from the tubing of the FMS 2000. In this laboratory investigation, the FMS 2000 performance was superior with respect to providing PRBC at physiologic temperatures (at 500 mL/min) and with respect to air detection and elimination compared with current widely used pressure-infuser technology. ⋯ The FMS 2000 and Level 1 H1025 warming capabilities were similar at metered flows of 500 mL/min. At more rapid flow rates, which are achieved by the H1025, fluid warming decreases dramatically. The air-detection and -elimination system of the FMS 2000 is superior to that of the H1025.
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Anesthesia and analgesia · Oct 2003
Clinical TrialBlood use in patients undergoing coronary artery bypass surgery: impact of cardiopulmonary bypass pump, hematocrit, gender, age, and body weight.
We investigated the impact of cardiopulmonary bypass pump (CPB), hematocrit, gender, age, and body weight on blood use in patients undergoing coronary artery bypass graft surgery at a major university hospital. Participants were 1235 consecutive patients undergoing primary coronary artery surgery over a period of 2 yr (1999 and 2000); 681 patients underwent coronary surgery with use of CPB, and 554 patients underwent off-pump coronary artery bypass surgery using a median sternotomy incision. There were 881 males and 354 females. Average packed red blood cells (PRBC) transfusion for patients on CPB was 3.4 U compared with 1.6 U for the off-pump group (P = <0.001). Patients on CPB received more frequent PRBC transfusion (72.5%) compared with 45.7% of off-pump patients (P = <0.001). Average PRBC transfusion for males was 2.2 U compared with 3.6 U for females (P = <0.001). A lower percentage of males (52.6%) than females (79.4%) received transfusion (P = <0.001). The impact of CPB, off-pump status, preoperative hematocrit <35%, gender, age >or=65 yr, and weight
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Anesthesia and analgesia · Oct 2003
Clinical TrialConfirmation of direct epidural catheter placement using nerve stimulation in pediatric anesthesia.
We evaluated the success rate of using low current electrical stimulation (the Tsui test) to identify and confirm direct epidural catheter placement in a pediatric population. Thirty subjects received a standard anesthetic and administration of the Tsui test on epidural placement. The distribution of myotomal activity was recorded. The intended and actual level of the epidural catheter was compared. Myotomal activity was seen in all patients but one. The median current resulting in myotomal activity was 5.3 mA. The median difference between the intended and actual level as confirmed on radiograph was 1.8 levels. The clinical success rate was 93.9%. The positive predictive value of the Tsui test was 82%; i.e., in 23 of 28 cases, the Tsui test correctly identified the position of the epidural catheter tip within 2 vertebral levels. The test did not offer any added advantage when used in the setting of directly placed epidural catheters in our institution over "blind" methods already used to confirm catheter position when using cutaneous landmarks and test dosing. ⋯ A new technique to confirm epidural catheter position uses low current electrical stimulation in pediatric patients. This study evaluated the use of electrical stimulation in 30 pediatric patients for directly placed catheters. Electrical stimulation did not provide any advantage over conventional methods (e.g., cutaneous landmarks) for confirmation of catheter position.