Pharmacokinetics of levobupivacaine 0.5% after superficial or combined (deep and superficial) cervical plexus block in patients undergoing minimally invasive parathyroidectomy.

STUDY OBJECTIVE: To evaluate the pharmacokinetic profile of 0.35 mL/kg of 0.5% levobupivacaine during superficial and combined (deep and superficial) cervical plexus block (CPB) in patients undergoing minimally invasive parathyroidectomy. DESIGN: Prospective randomized study. SETTING: Operating theater of a university hospital. PATIENTS: 12 ASA physical status II and III patients (11 women and 1 man), scheduled for minimally invasive parathyroidectomy. INTERVENTIONS: Seven and 5 patients were randomly assigned to receive either superficial or combined CPB, respectively. The superficial CPB was performed with an injection of 0.35 mL/kg of 0.5% levobupivacaine subcutaneously along the posterior border of the sternocleidomastoid muscle and deeper on its medial surface. The combined CPB was initiated by the deep block at the C3 level vertebra by injecting 0.2 mL/kg of 0.5% levobupivacaine, followed by the superficial block with an injection of the remaining 0.15 mL/kg. After completion of the block, venous blood was sampled at the intervals of 5, 10, 15, 20, 30, 45, and 60 minutes. MEASUREMENTS AND MAIN RESULTS: Venous plasma concentrations were measured using gas chromatography-mass spectroscopy. Mean +/- SD of maximal concentrations of levobupivacaine was 0.58 +/- 0.41 mg/L in group superficial and 0.52 +/- 0.28 mg/L in group combined (P = 0.71). The median (range) time required to reach the maximal concentrations was 30 minutes (20-30 min) in group superficial and 20 minutes (15-30 min) in group combined (P = 0.45). The areas under the drug concentration/time curve (AUC(10-60)) were also similar in both groups. No signs of central nervous system or cardiovascular toxicity or other untoward events were observed in any patient. CONCLUSION: With the given dose regimen, levobupivacaine plasma concentrations were within safe ranges.

Preoperative administration of controlled-release oxycodone as a transition opioid for total intravenous anaesthesia in pain control after laparoscopic cholecystectomy.

BACKGROUND: The complexity of pain from laparoscopic cholecystectomy and the need for treating incident pain provide rationale for multipharmacological analgesia. We investigated the preoperative administration of controlled-release (CR) oxycodone as transition opioid from remifentanil infusion for pain after laparoscopic cholecystectomy. METHODS: Fifty consecutive patients undergoing laparoscopic cholecystectomy were randomly, double-blindly assigned to treatment group (n=25, CR oxycodone: 1 h before surgery and 12 h after the first administration) or to the control group (n=25, placebo: administered at the same intervals). General anaesthesia was maintained with propofol and remifentanil target-controlled infusions (TCIs). All patients received ketorolac 30 mg i.v. Tramadol i.v. was administered for patient-controlled analgesia (PCA) postoperatively. Numerical rating scale for pain at rest and at movement (NRSr and NRSi), tramadol consumption, times to readiness to surgery and awakening, times to modified Aldrete's and modified Post-Anesthetic Discharge Scoring System (PADSS)>9 and side effects were evaluated. RESULTS: All NRSr and NRSi and tramadol consumption were significantly lower in the treatment group. The oxycodone group showed higher modified Aldrete's scores at each time and reached a PADSS>9 faster. Side effects and postoperative nausea and vomiting episodes were comparable. CONCLUSIONS: We demonstrated the success of a multipharmacological treatment including opioid premedication with CR oxycodone used as transition opioid for TCI remifentanil infusion; the treatment group showed lower pain scores and rescue analgesic consumption, shorter time to discharge from recovery room and from surgical ward, and the same incidence of side effects, comparably to controls.

Spinal anesthesia: an evergreen technique.

Spinal anesthesia is a simple technique that provides a deep and fast surgical block through the injection of small doses of local anesthetic solution into the subarachnoid space. The purpose of this review is to provide an overview on recent developments on local anesthetic drugs, side effects, and special techniques of intrathecal anesthesia. Spinal anesthesia can be considered adequately safe, and severe complications are reasonably rare. The cardiovascular effects associated with sympathetic block are more frequent, but successfully treated with volume expansion and administration of vasoactive drugs. It is clear that the total dose of local anesthetic injected into the subarachnoid space is the most important determinant of both therapeutic and unwanted effects of spinal anesthesia. Several studies have also demonstrated the efficacy and safety of using small doses of long acting agents, such as bupivacaine or ropivacaine, to produce an adequately short spinal block in outpatients. Levopivacaine, the pure S(-)-enantiomer of racemic bupivacaine showed a lower risk of cardiovascular and central nervous system (CNS) toxicity than bupivacaine. In the last years we have assisted important changes in the health care organization, with most of the surgical procedures performed on outpatients or on elderly patients with concomitant diseases. This forced us to change the indications and clinical use of intrathecal anesthesia techniques, which have been modified according to the changing needs of surgery. The development of new drugs and special techniques for spinal anesthesia will further improve the clinical use of this old but evergreen technique.

72-hour epidural infusion of 0.125% levobupivacaine following total knee replacement: a prospective, randomized, controlled, multicenter evaluation.

BACKGROUND AND AIM OF THE WORK: To evaluate the efficacy in terms of pain relief and degree of motor impairment of a continuous epidural infusion of 0.125% levobupivacaine in patients undergoing total knee replacement surgery. METHODS: 186 patients receiving effective epidural analgesia with 0.125% levobupivacaine during the first 24 hours after surgery were randomly allocated to receive postoperative analgesia for the following 48 hours consisting in either a continued epidural infusion of 0.125% levobupivacaine (Levobupivacaine group, n = 96), or IV PCA morphine only (Morphine PCA group, n = 90). An independent observer recorded the average amount of morphine required per hour following randomisation, pain intensity, degree of motor blockade and occurrence of side effects. RESULTS: Median (range) hourly morphine consumption during the study period was 0.21 (0.00-4.65) mg/hr in the Levobupivacaine group and 0.43 (0.04-4.65) mg/hr in the Morphine PCA group (P = 0.005). The quality of pain relief was adequate (VAS < 30 mm) in both groups, but patients in the Levobupivacaine group showed lower VAS values during motion than patients in the Morphine PCA group (P = 0.001). No differences in the proportion of patients with clinically relevant motor block (Bromage's score > or = 1) were reported between the two groups. CONCLUSIONS: Continuing the epidural infusion of a concentration of levobupivacaine as low as 0.125% improves pain relief with a 50% reduction of hourly morphine consumption after total knee replacement even during the second and third postoperative days, and does not result in a gross impairment of motor function.

Comparison of parecoxib and proparacetamol in endoscopic nasal surgery patients.

PURPOSE: The aim of the study was to compare the efficacy of parecoxib for postoperative analgesia after endoscopic turbinate and sinus surgery with the prodrug of acetaminophen, proparacetamol. MATERIALS AND METHODS: Fifty American Society of Anesthesiology (ASA) physical status I-II patients, receiving functional endoscopic sinus surgery (FESS) and endoscopic turbinectomy, were investigated in a prospective, randomized, double-blind manner. After local infiltration with 1% mepivacaine, patients were randomly allocated to receive intravenous (i.v.) administration of either 40 mg of parecoxib (n=25) or 2 g of proparacetamol (n=25) 15 min before discontinuation of total i.v. anaesthesia with propofol and remifentanil. A blinded observer recorded the incidence and severity of pain at admission to the post anaesthesia care unit (PACU) at 10, 20, and 30 min after PACU admission, and every 1 h thereafter for the first 6 postoperative h. RESULTS: The area under the curve of VAS (AUC(VAS)) calculated during the study period was 669 (28-1901) cm x min in the proparacetamol group and 635 (26-1413) cm x min in the parecoxib group (p=0.34). Rescue morphine analgesia was required by 14 patients (56%) in the proparacetamol group and 12 patients (48%) in the parecoxib (p >or= 0.05), while mean morphine consumption was 5-3.5mg and 5-2.0 mg in the proparacetamol groups and parecoxib, respectively (p >or= 0.05). No differences in the incidence of side effects were recorded between the 2 groups. Patient satisfaction was similarly high in both groups, and all patients were uneventfully discharged 24 h after surgery. CONCLUSION: In patients undergoing endoscopic nasal surgery, prior infiltration with local anaesthetics, parecoxib administered before discontinuing general anaesthetic, is not superior to proparacetamol in treating early postoperative pain.

A prospective, randomized comparison between combined (deep and superficial) and superficial cervical plexus block with levobupivacaine for minimally invasive parathyroidectomy.

BACKGROUND: Minimally invasive parathyroidectomy (MIP) can be performed under cervical plexus block (CPB). Superficial CPB has been reported to be easier to perform with similar efficacy and less anesthesia-related complications than combined deep and superficial CPB. In this study, we compared the efficacy of superficial and combined (deep and superficial) CPB in patients undergoing MIP. METHODS: Forty-two patients with primary hyperparathyroidism due to a solitary adenoma were randomized to receive either a superficial (group superficial, n = 20) or a combined deep and superficial CPB (group combined, n = 22) using 0.35 mL/kg of 0.5% levobupivacaine. The primary end-point was the amount of supplemental fentanyl required to complete surgery. RESULTS: There were no differences in onset of block, pain scores during surgery, or time to first analgesic request between groups. Fentanyl consumption was similar in both groups, i.e., 50 (0-200) microg in group superficial and 50 (0-100) microg in group combined (P = 0.60). Six patients [1 in group superficial (5%) and 5 in group combined (22.7%)] were converted to general anesthesia for surgically required bilateral neck dissection (P = 0.18). General anesthesia for block failure was reported in three superficial (15%) and two combined group patients (9%) (P = 0.99). In group combined, only one patient (4.5%) showed diaphragmatic paresis after the block (P = 0.99). CONCLUSION: Superficial CPB is an alternative to combined block for MIP.

Forehead reflectance oximetry: a clinical comparison with conventional digit sensors during laparotomic and laparoscopic abdominal surgery.

OBJECTIVE: This study compared the performance of forehead reflectance and conventional pulse oximetry (SpO(2)) in mechanically ventilated, anesthetized patients undergoing major abdominal surgery with either laparoscopic or laparotomic techniques. METHODS: SpO(2) was continuously measured both with a forehead reflectance and a conventional digit sensor in 20 ASA physical status I-III, anesthetized patients undergoing either a laparotomic (group Laparotomy, n = 10) or laparoscopic (group Laparoscopy, n = 10) major abdominal surgery. SpO(2) values measured with the two sensors were continuously recorded at 10-second intervals during the entire procedure, and then analyzed for consistency. RESULTS: In group Laparotomy finger and forehead readings remained consistently similar during the study period; on the contrary, in group Laparoscopy forehead SpO(2) readings showed a much wider variability. The mean (95% Confidence Intervals) difference between finger and forehead SpO(2) readings was 2.0% (-1.3% to +6.0%) in group Laparotomy and 2.5% (-3.5% to +8.4%) in group Laparoscopy (p = 0.001); however, in group Laparoscopy the mean difference between digit and forehead SpO(2) values increased from 0.2% (CI(95): -2.1% to +2.5%) during the first hour to 4.5% (CI(95): -2.5% to +11-5%) in the second hour (p = 0.0005), and 3.1% (CI(95): -2.4% to + 8.6%) in the third hour of surgery (p = 0.0005). Clinically relevant desaturation (decrease of SpO(2) < 89% for > or =30 s) detected with the forehead sensor in the Laparoscopy group was significantly more frequent and longer lasting than with conventional digit sensor. No differences were observed in group Laparotomy. CONCLUSIONS: Forehead reflectance oximetry is as accurate as conventional digit based oximetry in mechanically ventilated patients undergoing laparotomic surgery in the supine position, but is significantly influenced by patient positioning and pneumoperitoneum during laparoscopic surgery.

A prospective, randomized comparison between ultrasound and nerve stimulation guidance for multiple injection axillary brachial plexus block.

BACKGROUND: This prospective, randomized, blinded study tested the hypothesis that ultrasound guidance can shorten the onset time of axillary brachial plexus block as compared with nerve stimulation guidance when using a multiple injection technique. METHODS: Sixty American Society of Anesthesiology physical status I-III patients receiving axillary brachial plexus block with 20 ml ropivacaine, 0.75%, using a multiple injection technique, were randomly allocated to receive either nerve stimulation (group NS, n = 30), or ultrasound guidance (group US, n = 30) for nerve location. A blinded observer recorded the onset of sensory and motor blocks, the need for general anesthesia (failed block) or greater than 100 microg fentanyl (insufficient block) to complete surgery, procedure-related pain, success rate, and patient satisfaction. RESULTS: The median (range) number of needle passes was 4 (3-8) in group US and 8 (5-13) in group NS (P = 0.002). The onset of sensory block was shorter in group US (14 +/- 6 min) than in group NS (18 +/- 6 min) (P = 0.01), whereas no differences were observed in onset of motor block (24 +/- 8 min in group US and 25 +/- 8 min in group NS; P = 0.33) and readiness to surgery (26 +/- 8 min in group US and 28 +/- 9 min in group NS; P = 0.48). No failed block was reported in either group. Insufficient block was observed in 1 patient (3%) of group US and 2 patients (6%) of group NS (P = 0.61). Procedure-related pain was reported in 6 patients (20%) of group US and 14 patients (48%) of group NS (P = 0.028); patient acceptance was similarly good in the two groups. CONCLUSION: Multiple injection axillary block with ultrasound guidance provided similar success rates and comparable incidence of complication as compared with nerve stimulation guidance.

Spinal anesthesia with lidocaine or preservative-free 2-chlorprocaine for outpatient knee arthroscopy: a prospective, randomized, double-blind comparison.

BACKGROUND: In this prospective, randomized, double-blind study we tested the hypothesis that 50 mg of 1% preservative-free 2-chloroprocaine would provide a faster resolution of spinal block than the same dose of 1% plain lidocaine. METHODS: After IV midazolam premedication (0.03 mg/kg), 30 ASA physical status I-II outpatients undergoing knee arthroscopy were randomly allocated to receive 50 mg of either 1% plain lidocaine (n = 15) or 1% preservative-free plain chloroprocaine (n = 15). A blinded observer recorded the evolution of sensory (loss of pinprick sensation) and motor (modified Bromage scale) block until complete regression, as well as times to unassisted ambulation and voiding. A telephone call follow-up was performed 24 h and 7 days after surgery. RESULTS: Two chloroprocaine patients (13%) and one lidocaine patient (7%) required fentanyl supplementation (100 microg IV) (P = 0.99) intraoperatively, but no patient required general anesthesia to complete surgery. Median (range) times for recovery of sensory and motor function, and unassisted ambulation were faster with 2-chloroprocaine [95 (68-170) min; 60 (45-120) min; and 103 (70-191) min] than lidocaine [120 (80-175) min; 100 (60-140) min; and 152 (100-185) min] (P = 0.019, P = 0.0005, and P = 0.003, respectively). No differences in first voiding were reported between chloroprocaine [180 (100-354) min] and lidocaine patients [190 (148-340) min] (P = 0.191). Transient neurological symptoms were reported in five lidocaine patients (33%) but no chloroprocaine patients (0%) (P = 0.042). CONCLUSION: Intrathecal injection of 50 mg of preservative-free 2-chloroprocaine 1% resulted in quicker recovery of sensory/motor function, and unassisted ambulation, and fewer incidences of transient neurologic symptoms than the same dose of 1% lidocaine.

Clinical complications, monitoring and management of perioperative mild hypothermia: anesthesiological features.

BACKGROUND AND AIM OF THE WORK: Perioperative hypothermia is a frequent occurrence and can lead to several complications, which adversely affect the patient's outcome, expecially in high risk patient. Nonetheless, central temperature is not frequently monitored in the clinical routine. The aim of this work is to make the point on complications, monitoring techniques, prevention and treatment of mild perioperative hypothermia. METHODS: We reviewed literature on cardiovascular, haemorragic, infectious, and other clinical consequences of mild intraoperative hypothermia, epidemiology and techniques, of temperature monitoring and efficacy of different approaches for the prevention and treatment of mild hypothermia. RESULTS: Cardiovascular, haemorragic and infectious complications are significantly more frequent in hypothermic than in normothermic patients. Elderly and high risk patients are more prone to develop perioperative hypotherma, and are more liable to hypothermia-related complications. The ideal monitoring site has to be chosen considering both the patients characteristics and surgical procedure. Once identified, hypothermia has to be treated and the most effective systems are represented by active forced-air skin warming system. Active prewarming during the preoperative period has been also demonstrated to be efficient in reducing the development of intraoperative hypothermia. Humidification and warming of inspired gases, and warming of intravenous fluids are useful techniques when used in a multimodal approach with active skin warming to maintain perioperative normothermia. CONCLUSIONS: All the patient undergoing surgery for more than 30 minutes should receive an accurate temperature monitoring and a correct management for the maintenance of normothermia. Reducing the incidence and severity of perioperative hypothermia has the potential for drastically reducing complication-related costs.

Synthesis and cytotoxic activity of polyamine analogues of camptothecin.

A number of derivatives of camptothecin with a polyamine chain linked to position 7 of camptothecin via an amino, imino, or oxyiminomethyl group were synthesized and tested for their biological activity. All compounds showed marked growth inhibitory activity against the H460 human lung carcinoma cell line. In particular, the iminomethyl derivatives where the amino groups of the chain were protected with Boc groups exhibited a high potency, with IC50 values of approximately 10(-8) M. The pattern of DNA cleavage in vitro and the persistence of the cleavable ternary complex drug-DNA-topoisomerase I observed with polyamine conjugates containing free amino groups support a contribution of specific drug interaction with DNA as a determinant of activity. Modeling of compound 7c in the complex with topoisomerase 1 and DNA is consistent with this hypothesis. The lack of a specific correlation between stabilization of the cleavable complex and growth inhibition likely reflects multiple factors including the cellular pharmacokinetic behavior related to the variable lipophilicity of the conjugate, and the nature and linkage of the polyamine moiety.

Early increases in cardiac troponin levels after major vascular surgery is associated with an increased frequency of delayed cardiac complications.

OBJECTIVE: To evaluate changes in cardiac troponin-I levels after major vascular surgery and their association with early and late postoperative cardiac complications. DESIGN: Prospective, observational investigation. SETTING: University teaching hospital. PATIENTS: 75 consecutive patients undergoing major vascular surgery. INTERVENTIONS: All patients received a standard sevoflurane-fentanyl anesthesia during the procedure. Blood levels of creatine kinase with MB subtype and cardiac troponin-I were assessed before surgery and then everyday for the first 3 days after surgery. At the same time, 12-lead electrocardiography was also performed, and occurrence of any cardiac adverse event was recorded. Patients were then followed up for 1 month after surgery. MEASUREMENT AND MAIN RESULTS: Troponin-I levels increased in 25 patients (33%) during the first 3 days after surgery; 9 of these patients (12%) had myocardial infarction. At univariate analysis, uncontrolled hypertension was the only risk factor for perioperative infarction (odds ratio, 16; (95% confidence interval, 3-74); however, multivariate logistic regression analysis failed to show statistically significant associations. Increases in troponin-I had a 100% sensitivity and 75% specificity in detecting myocardial ischemia with a 36% positive and 100% negative predictive values. Severe cardiac complication 1 month after surgery was reported in 5 patients (6.6%). The increase of cardiac troponin-I levels during the first 3 postoperative days was associated with an increased frequency of major cardiac complication at 1-month follow-up (P = 0.003), with a 100% sensitivity, 71% specificity, and 100% negative predictive value. CONCLUSIONS: Myocardial infarction after major noncardiac vascular surgery occurs in up to 12% of cases. Perioperative monitoring of troponin-I plasma levels may help to identify patients at increased risk for cardiac morbidity not only early after surgery but also during the first postoperative month.

Intrathecal 2-chloroprocaine for lower limb outpatient surgery: a prospective, randomized, double-blind, clinical evaluation.

We evaluated the dose-response relationship of 2-chloroprocaine for lower limb outpatient procedure in 45 ASA physical status I-II outpatients undergoing elective lower limb surgery under spinal anesthesia, with 30 mg (group Chlor-30, n = 15), 40 mg (group Chlor-40, n = 15), or 50 mg (group Chlor-50, n = 15) of 1% preservative free 2-chloroprocaine. Onset time was similar in the three groups. General anesthesia was never required to complete surgery. Intraoperative analgesic supplementation as a result of insufficient duration of spinal block was required in 5 patients of group Chlor-30 (35%) and 2 patients of group Chlor-40 (13%) (P = 0.014), with a median (range) time for supplementation request of 40 (30-60) min. Spinal block resolution and recovery of ambulation were faster in group Chlor-30 (60 [41-98] min and 85 [45-123] min) than in groups Chlor-40 (85 [46-141] min and 180 [72-281] min) and Chlor-50 (97 [60-169] min and 185 [90-355] min) (P = 0.001 and P = 0.003, respectively), with no differences in home discharge time (182 [120-267] min in group Chlor-30, 198 [123-271] min in group Chlor-40, and 203 [102-394] min in group Chlor-50; P = 0.155). No transient neurologic symptoms were reported at 24-h and 7-day follow-up. We conclude that although 40 and 50 mg of 2-chloroprocaine provide adequate spinal anesthesia for outpatient procedures lasting 45-60 min, 30 mg produces a spinal block of insufficient duration.

A clinical evaluation of near-infrared cerebral oximetry in the awake patient to monitor cerebral perfusion during carotid endarterectomy.

STUDY OBJECTIVE: To evaluate the relationship between continuous noninvasive monitoring of cerebral saturation (regional cerebral oxygen saturation [rSo2]) and occurrence of clinical and electroencephalographic (EEG) signs of cerebral ischemia during carotid cross-clamping. DESIGN: Prospective clinical study. SETTING: University hospital. PATIENTS: Fifty ASA physical status II and III inpatients undergoing elective carotid endarterectomy with a cervical plexus block. INTERVENTIONS: rSo2 was continuously monitored throughout surgery, while an independent neurologist evaluated the occurrence of both clinical and EEG signs of cerebral ischemia induced during carotid cross-clamping. MEASUREMENTS AND MAIN RESULTS: rSo2 was recorded 1 and 3 minutes after clamping the carotid artery during a 3-minute clamping test. In 5 patients (10%), the carotid clamping test was associated with the occurrence of clinical and EEG signs of cerebral ischemia. All these patients were treated with the placement of a Javid shunt, which completely resolved the symptoms. In no patient was permanent neurological injury reported at hospital discharge. In 4 of these patients, EEG signs of cerebral ischemia were present at both observation times, and in one of them, the duration of cerebral ischemia was less than 2 minutes. The percentage rSo2 reduction from baseline during the carotid clamping test was 17% +/- 4% in patients requiring shunt placement and only 8% +/- 6% in those who did not require it (P = .01). A decrease in rSo2 15% or greater during the carotid clamping test was associated with a 20-fold increase in the odd for developing severe cerebral ischemia (odds ratio, 20; 95% confidence interval, 6.7-59.2) (P = .001); however, this threshold had a 44% sensitivity and 82% specificity, with only 94% negative predictive value. CONCLUSIONS: Continuous rSo2 monitoring is a simple and noninvasive method that correlates with the development of clinical and EEG signs of cerebral ischemia during carotid cross-clamping; however, we could not identify an rSo2 threshold that can be used alone to predict the need for shunt placement because of the low sensitivity and specificity.

Using stimulating catheters for continuous sciatic nerve block shortens onset time of surgical block and minimizes postoperative consumption of pain medication after halux valgus repair as compared with conventional nonstimulating catheters.

UNLABELLED: We prospectively tested the hypothesis that the use of a stimulating catheter improves the efficacy of continuous posterior popliteal sciatic nerve block in 100 randomized patients scheduled for elective orthopedic foot surgery. After eliciting a sciatic mediated muscular twitch at < or = 0.5 mA nerve stimulation output, the perineural catheter was advanced 2-4 cm beyond the tip of the introducer either blindly (Group C; n = 50) or stimulating via the catheter (Group S; n = 50). A bolus dose of 25 mL of 1.5% mepivacaine was followed by a postoperative patient-controlled infusion of 0.2% ropivacaine (basal infusion: 3 mL/h; incremental dose: 5 mL; lockout time: 30 min). Propacetamol 2 g IV was administered every 8 h, and opioid rescue analgesia was available if required. Catheter placement required 7 +/- 2 min in Group S and 5 +/- 2 min in Group C (P = 0.056). A significantly shorter onset time of both sensory and motor blocks was noted in Group S. No difference in quality of pain relief at rest and during motion was reported between the groups. Median (range) local anesthetic consumption during the first 48 h after surgery was 239 mL (175-519 mL) and 322 mL (184-508 mL) in Groups S and C, respectively (P = 0.002). Rescue opioid analgesia was required by 12 (25%) and 28 (58%) patients in Groups S and C, respectively (P = 0.002). We conclude that the use of a stimulating catheter results in shorter onset time of posterior popliteal sciatic nerve block, similar pain relief with reduced postoperative consumption of local anesthetic solution, and less rescue opioid consumption. IMPLICATIONS: This prospective, randomized, blind investigation demonstrated that the use of a stimulating catheter for continuous posterior popliteal sciatic nerve block resulted in shorter onset time of sensory and motor blocks and less local anesthetic consumption and need for rescue pain medication after elective orthopedic foot surgery compared with blind catheter advancement.

Continuous monitoring of cerebral oxygen saturation in elderly patients undergoing major abdominal surgery minimizes brain exposure to potential hypoxia.

Elderly patients are more prone than younger patients to develop cerebral desaturation because of the reduced physiologic reserve that accompanies aging. To evaluate whether monitoring cerebral oxygen saturation (rSO(2)) minimizes intraoperative cerebral desaturation, we prospectively monitored rSO(2) in 122 elderly patients undergoing major abdominal surgery with general anesthesia. Patients were randomly allocated to an intervention group (the monitor was visible and rSO(2) was maintained at > or =75% of preinduction values; n = 56) or a control group (the monitor was blinded and anesthesia was managed routinely; n = 66). Cerebral desaturation (rSO(2) reduction <75% of baseline) was observed in 11 patients of the treatment group (20%) and 15 patients of the control group (23%) (P = 0.82). Mean (95% confidence intervals) values of mean rSO(2) were higher (66% [64%-68%]) and the area under the curve below 75% of baseline (AUCrSO2(2)< 75% of baseline) was lower (0.4 min% [0.1-0.8 min%]) in patients of the treatment group than in patients of the control group (61% [59%-63%] and 80 min% [2-144 min%], respectively; P = 0.002 and P = 0.017). When considering only patients developing intraoperative cerebral desaturation, a lower Mini Mental State Elimination (MMSE) score was observed at the seventh postoperative day in the control group (26 [25-30]) than in the treatment group (28 [26-30]) (P = 0.02), with a significant correlation between the AUCrSO(2) < 75% of baseline and postoperative decrease in MMSE score from preoperative values (r(2)= 0.25, P = 0.01). Patients of the control group with intraoperative cerebral desaturation also experienced a longer time to postanesthesia care unit (PACU) discharge (47 min [13-56 min]) and longer hospital stay (24 days [7-53] days) compared with patients of the treatment group (25 min [15-35 min] and 10 days [7-23 days], respectively; P = 0.01 and P = 0.007). Using rSO(2) monitoring to manage anesthesia in elderly patients undergoing major abdominal surgery reduces the potential exposure of the brain to hypoxia; this might be associated with decreased effects on cognitive function and shorter PACU and hospital stay.

Effects of mild hypothermia on blood coagulation in patients undergoing elective plastic surgery.

BACKGROUND: The aim of this prospective, controlled study was to evaluate the effects on coagulation function of active patient warming during elective plastic surgery. METHODS: Seventy-six patients undergoing elective plastic surgery (additive and reductive mastoplasty, rhinoplasty, and liposuction) were either covered with standard sterile drapes (control group, n = 38) or actively warmed during surgery with countercurrent fluid warming and forced-air skin warming (treatment group, n = 38). Complete evaluation of the coagulation activity was performed 1 hour before general anesthesia was induced and then at the end of surgery. RESULTS: Although no differences in preoperative core temperature were observed (36.0 +/- 0.5 degrees C in the control group and 36.1 +/- 0.4 degrees C in the treatment group; p = 0.12), core temperature was lower at the end of surgery in the control group (34 +/- 1.0 degrees C) than in the treatment group (36 +/- 0.6 degrees C) (p = 0.0005). No differences in prothrombin time and fibrinogen plasma concentrations were observed between the two groups. At the end of surgery, control group patients showed significantly larger activated partial thromboplastin times (36.8 +/- 3.5 seconds) and bleeding times (8.1 +/- 1.6 minutes) as compared with patients maintained normothermic during surgery (34.0 +/- 2.9 seconds and 4.3 +/- 1.1 minutes; p = 0.0005 and p = 0.0005, respectively). CONCLUSION: Actively maintaining intraoperative normothermia allows patients to maintain normal coagulation function during elective plastic surgery lasting longer than 2 hours, potentially reducing the occurrence of bleeding-related complications after plastic surgery.

Spinal anesthesia with hyperbaric levobupivacaine and ropivacaine for outpatient knee arthroscopy: a prospective, randomized, double-blind study.

To compare unilateral spinal block produced with small doses of hyperbaric ropivacaine with that produced by 2 doses of hyperbaric levobupivacaine, we randomly allocated 91 ASA physical status I-II outpatients undergoing knee arthroscopy to receive unilateral spinal anesthesia with 7.5 mg of hyperbaric ropivacaine 0.5% (group Ropi-7.5, n = 31) or either 7.5 mg (group Levo-7.5, n = 30) or 5 mg (group Levo-5, n = 30) of hyperbaric levobupivacaine 0.5%. Spinal anesthesia was performed at the L3-4 interspace using a 25-gauge Whitacre spinal needle. The lateral decubitus position was maintained for 15 min after injection. Strictly unilateral sensory block was present in 73%, 50%, and 61% of cases in groups Ropi-7.5, Levo-7.5, and Levo-5, respectively, 30 min after injection (P = 0.40), and unilateral motor block was observed in 94%, 93%, and 83% in groups Ropi-7.5, Levo-7.5, and Levo-5, respectively (P = 0.31). One patient of group Ropi-7.5 required general anesthesia to complete surgery, and fentanyl supplementation was required in one patient of group Ropi-7.5 (3%) and one patient of group Levo-5 (3%) (P = 0.42). The median (range) time for spinal block resolution was shorter in group Ropi-7.5 (135 [126-154] min] than in group Levo-7.5 (162 [148-201] min) (P = 0.04); whereas home discharge was shorter in groups Ropi-7.5 (197 [177-218] min) and Levo-5 (197 [187-251] min) as compared with group Levo-7.5 (238 [219-277] min) (P = 0.02 and P = 0.04, respectively). We conclude that 7.5 mg of 0.5% hyperbaric ropivacaine and 5 mg of 0.5% hyperbaric levobupivacaine provide adequate spinal block for outpatient knee arthroscopy, with a faster home discharge as compared with 7.5 mg of 0.5% hyperbaric levobupivacaine.

The effect-site concentration of remifentanil blunting cardiovascular responses to tracheal intubation and skin incision during bispectral index-guided propofol anesthesia.

We sought to determine the effect-site concentration of remifentanil blunting sympathetic responses to tracheal intubation and skin incision during bispectral index (BIS)-guided propofol anesthesia. Forty-one ASA physical status I-II patients, aged 20-65 yr and undergoing major abdominal surgery, were randomly assigned to one of two groups: tracheal intubation (group TI, n = 20) or skin incision (group SI, n = 21). All patients received a target-controlled infusion of propofol of 4 microg/mL, which was then adjusted to maintain a BIS value ranging between 40 and 50. The effect-site concentration of remifentanil blocking the sympathetic responses to tracheal intubation and skin incision in 50% of cases (Ce50) was determined using an up-and-down sequential allocation method. The mean (95% confidence interval [CI]) Ce50 of remifentanil was 5.0 ng/mL for TI (95% CI, 4.7-5.4 ng/mL) and 2.1 ng/mL for SI (95% CI, 1.4-2.8 ng/mL). This study shows that effect-site concentrations of remifentanil of 5 ng/mL and 2 ng/mL are effective in blunting sympathetic responses to tracheal intubation and skin incision in 50% of patients when combined with a BIS-guided target controlled infusion of propofol.

Four different airway-management strategies in patient with Launois-Bensaude syndrome or Madelung's disease undergoing surgical excision of neck lipomatosis with a complicated postoperative course.

Launois-Bensaude syndrome, otherwise known as Madelung's disease, is a rare disorder characterized by fatty accumulations of the upper trunk, neck and head, causing serious cosmetic deformity and neck immobility. We report a case of a patient with Launois-Bensaude syndrome who required 4 different airway management strategies during his hospitalization for postoperative complications after an elective surgical excision of a severe neck lipomatosis. Anesthesiologists who treat patients with Madelung's disease should be aware of 2 major problems: difficult airway and increased frequency of postoperative bleeding. A proper choice of airway management technique is therefore necessary, including a safe intubation and extubation plan to reduce the consequences of airway complications.