As the number of ambulatory surgery procedures continues to grow in an aging global society, the implementation of evidence-based perioperative care programs for the elderly will assume increased importance. Given the recent advances in anesthesia, surgery, and monitoring technology, the ambulatory setting offers potential advantages for elderly patients undergoing elective surgery. In this review article we summarize the physiologic and pharmacologic effects of aging and their influence on anesthetic drugs, the important considerations in the preoperative evaluation of elderly outpatients with coexisting diseases, the advantages and disadvantages of different anesthetic techniques on a procedural-specific basis, and offer recommendations regarding the management of common postoperative side effects (including delirium and cognitive dysfunction, fatigue, dizziness, pain, and gastrointestinal dysfunction) after ambulatory surgery. We conclude with a discussion of future challenges related to the growth of ambulatory surgery practice in this segment of our surgical population. When information specifically for the elderly population was not available in the peer-reviewed literature, we drew from relevant information in other ambulatory surgery populations.

Objective To report data about “real-life” treatments with non-invasive ventilation for acute respiratory failure (ARF), managed outside intensive care units by anaesthesiologists acting as a medical emergency team. Design Observational study; prospectively collected data over a 6-month period in a single centre. Setting Non-intensive wards in a University Hospital with 1,100 beds. Patients Consecutive patients with ARF for whom a ventilatory support was indicated but tracheal intubation was not appropriated or immediately needed. Interventions None. Measurements and results Patient’s characteristics, safety data, short-term outcome and organizational aspects of 129 consecutive treatments were collected. The overall success rate was 77.5%, while 10.1% were intubated and 12.4% died (all of them were “do not attempt resuscitation” patients). The incidence of treatment failure varied greatly among different diseases. Complications were limited to nasal decubitus (5%), failure to accomplish the prescribed ventilatory program (12%), malfunction of the ventilator (2%) and excessive air leaks from face mask (2%) with no consequences for patients. Three patients became intolerant to NIV. The work-load for the MET was high but sustainable: on average NIV was applied to a new case every 34 h and more than three patients were simultaneously treated. Conclusions Under the supervision of a MET, in our institution NIV could be applied in a wide variety of settings, outside the ICU, with a high success rate and with few complications.

OBJECTIVES: The aim was to compare patients' and endoscopists' satisfaction in terms of efficacy and safety of remifentanil patient-controlled analgesia (PCA) during colonoscopy with that of a combination of midazolam and meperidine.METHODS: Sixty patients undergoing colonoscopy were randomly assigned to two groups. All of the patients received midazolam 0.03 mg/kg intravenously for premedication. In the remifentanil group, a bolus dose of remifentanil was given, and a patient-controlled sedation analgesia (PCSA) pump was set to inject further bolus doses with no "lockout" time. Patients in the meperidine group received a bolus of meperidine and sham PCSA. Non-invasive arterial blood pressure, electrocardiography, and pulse oximetry were monitored throughout the study. The Observer's Assessment of Alertness and Sedation Scale (OAA/S) was performed at baseline, every 5 min during, and after colonoscopy. Assessment of pain and satisfaction with sedoanalgesia was scheduled after colonoscopy and 24-72 h later by a 100 mm visual analog scale (VAS). The technical difficulty of the examination and the gastroenterologist's satisfaction were assessed similarly.RESULTS: The degree of pain, the level of satisfaction with sedoanalgesia by patients and gastroenterologists, and the degree of difficulty experienced by the endoscopist were not different in the two groups. The time to reach an Aldrete score >= 9 was significantly shorter in the remifentanil group (P < 0.0001); discharge times did not differ between the groups (P = 0.36). There was no difference between the groups regarding the duration of colonoscopy (P = 0.82) and the stability of vital signs. At the end of the procedure, OAA/S was significantly higher in the remifentanil group (P = 0.03).CONCLUSIONS: Remifentanil PCA is safe and effective to induce sedoanalgesia during colonoscopy. Further studies should address the optimization of dosing and lock out setting.

OBJECTIVES:The authors performed a meta-analysis to investigate whether the cardioprotective effects of volatile anesthetics translate into decreased morbidity and mortality in patients undergoing cardiac surgery.BACKGROUND:It is commonly believed that the choice of the primary anesthetic agent does not result in different outcomes after cardiac surgery. Recent evidence, however, has indicated that volatile anesthetics improve postischemic recovery at a cellular level, in isolated hearts, in animals, and in humans.METHODS:Four investigators independently searched BioMedCentral and PubMed. Inclusion criteria were random allocation to treatment and comparison of a total intravenous anesthesia regimen versus an anesthesia plan including desflurane or sevoflurane performed on cardiosurgical patients. Exclusion criteria were duplicate publications, nonhuman experimental studies, and no outcome data. The endpoints were the rate of perioperative myocardial infarction and hospital mortality.RESULTS:The search yielded 22 studies, involving 1,922 patients. Volatile anesthetics were associated with significant reductions of myocardial infarctions (24/979 [2.4%] in the volatile anesthetics group v 45/874 [5.1%] in the control arm, odds ratio [OR] = 0.51 [0.32-0.84], p for effect = 0.008, and p for heterogeneity = 0.77) and mortality (4/977 [0.4%] v 14/872 [1.6%], OR = 0.31 [0.12-0.80], p for effect = 0.02, and p for heterogeneity = 0.88).CONCLUSIONS:Desflurane and sevoflurane have cardioprotective effects that result in decreased morbidity and mortality. The present data show for the first time that the choice of an anesthetic regimen based on administration of halogenated anesthetics is associated with a better outcome after cardiac surgery.

BACKGROUND AND OBJECTIVES:The aim of this prospective, observational study was to evaluate changes in regional cerebral oxygen saturation (rSO2) and incidence of intraoperative cerebral desaturation in a cohort of elderly patients undergoing major abdominal surgery. METHODS:rSO2 was continuously monitored on the left and right sides of the forehead in 60 patients older than 65 yr (35 males and 25 females; ASA II-III; age: 72 +/- 5 yr; without pre-existing cerebral pathology, and baseline Mini Mental State Examination (MMSE) score >23) undergoing sevoflurane anaesthesia for major abdominal, non-vascular surgery >2 h. RESULTS:Baseline rSO2 was 63 +/- 8%; cerebral desaturation (rSO2 decrease <75% of baseline or <80% in case of baseline rSO2 <50%) occurred in 16 patients (26%). The MMSE decreased from 28 +/- 1 before surgery to 27 +/- 2 on 7th postoperative day (P = 0.05). A decline in cognitive function (decrease in MMSE score > or = 2 points one week after surgery as compared to baseline value) was observed in six patients without intraoperative cerebral desaturation (13.6%) and six patients who had intraoperative cerebral desaturation (40%) (P = 0.057) (odds ratio: 4.22; CI95%: 1.1-16). Median (range) hospital stay was 14 (5-41) days in patients with an area under the curve of rSO2 <50% (AUCrSO2<50%) >10 min%, and 10 (4-30) days in those with an AUCrSO2<50% <10 min% (P = 0.0005). CONCLUSIONS:In a population of healthy elderly patients, undergoing non-vascular abdominal surgery cerebral desaturation can occur in up to one in every four patients, and the occurrence of cerebral desaturation is associated with a higher incidence of early postoperative cognitive decline and longer hospital stay.

Background and objectives: The aim of this prospective, randomized, double-blind study was to determine the effects of adding two different target-controlled concentrations of remifentanil (1 and 3 ng mL(-1)) on the desflurane requirement for blunting sympathetic responses after surgical incision (minimum anaesthetic concentration (MAC(BAR))). Methods: 67 patients, aged 20-50 yr, ASA I, undergoing general anaesthesia for elective abdominal surgery were enrolled and randomly allocated to receive no remifentanil infusion (n = 21) or a target-controlled effect-site concentrationof 1 ng mL(-1) (n = 24)or 3 ng mL(-1) remifentanil (n = 22). All patients were anaesthetized with propofol, cisatracurium and desflurane with a mixture of 60% nitrous oxide in oxygen. Sympathetic responses to surgical incision were determined after a 20-min period of stable end-tidal desflurane and target-controlled remifentanil concentrations. Predetermined end-tidal desflurane concentrations and the MACBAR for each group were determined using an up-and-down sequential-allocation technique. Results: The MACBAR of desflurane was higher in the group receiving no remifentanil (6.25% [95% confidence interval: 5.9-6.5%]) as compared with patients of the groups receiving 1 ng mL(-1) (2.7% [2.6-2.8%]; P < 0.001) and 3 ng mL(-1) remifentanil (2% [1.9-2.2%]; P < 0.01). When considering a MAC value in this age population and the contribution of 60,76 nitrous oxide (0.55 MAC), the combined MACBAR values, expressed as multiples of the MAC, were 1.9, 0.8 and 0.6 MAC, in the three groups, respectively. Conclusion: A target-controlled concentration of 1 ng mL(-1) remifentanil results in a 57% decrease in the MACBAR of desflurane combined with 60% nitrous oxide. Increasing the target concentration of remifentanil to 3 ng mL(-1) produces a further 26% decrease in the MACBAR values of desflurane.

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.

Study Objective: To evaluate the efficacy of three different concentrations of ropivacaine (0.5%, 0.75%, and 1%) together with a single concentration of hyaluronidase administered for peribulbar block.Design: Prospective, randomized, double-blind study.Setting: Anesthesia department of a university teaching hospital.Patients: 68 ASA physical status I, II, and III patients undergoing elective cataract surgery.Interventions: Patients were randomly allocated to receive peribulbar block with 65 mL of either 0.5% (Group Ropi-5; n = 22), 0.75% (Group Ropi-7.5; n = 22), or 1% ropivacaine (Group Ropi-10, n = 24). In all patients, 0.5 mL of hyaluronidase was added to the local anesthetic solution.Measurements and Main Results: A larger proportion of patients in Groups Ropi-7.5 (82%) and Ropi-10 (83%) showed complete motor block 15 minutes after injection compared with Group Ropi-5 (55%; p = 0.05, and p = 0.03, respectively). Hypotension (reduction of systolic blood pressure by 30% or more from baseline) was observed in two Group Ropi-5 patients (9%), and two Group Ropi-7.5 patients (9%; p = 0.31), whereas bradycardia (reduction in heart rate less than or equal to 50 bpm) was observed in one Group Ropi-5 patient (4%), and three Group Ropi-10 patients (12%; p = 0.18). Seven hours after surgery, a smaller proportion of Group Ropi-10 patients (64%) showed complete recovery of sensory function as compared with both Group Ropi-5 (94%) and Group Ropi-7.5 (90%; p = 0.03 and p = 0.03, respectively). Complete recovery of motor function 1 hour after surgery was more frequent in Group Ropi-5 (37%) than in Group Ropi-7.5 (5%) or Group Ropi-10 (9%; p = 0.05 and p = 0.05, respectively); however, no other differences in recovery of motor function were observed at any other observation times, with complete recovery in all patients 7 hours after surgery.Conclusions: While confirming that ropivacaine is a good option for peribulbar anesthesia, this study demonstrated that the use of 0.75% or 1% concentrations are Preferred in that they produce quick and deep sensory and motor block of the operated eye. If recovery of normal motor function is important after surgery, the 0.75% concentration probably represents the best compromise. (C) 2004 by Elsevier Inc.

Background. A target-controlled infusion system automatically adjusts the rate of infusion of propofol to maintain a desired (target) concentration. The aim of this study was to determine whether administration of propofol with a target-controlled infusion system could improve the sedation of patients undergoing ERCP.Methods: A total of 205 consecutive patients undergoing ERCP were sedated by using a propofol target-controlled infusion system by an anesthesiologist. The target plasma concentration of propofol ranged from 2 to 5 mug/mL. A bolus dose of fentanyl (50-100 mcg) was administered if signs of insufficient analgesia were observed at the maximum target concentration of propofol allowed. The technical difficulty of ERCP was graded on a scale from 1 (least difficult) to 5 (most difficult).Results: The mean dosages of propofol and fentanyl administered were 465 (245) mg and 59 (23) mcg, respectively. The total dose of propofol administered and the mean duration of ERCP were related to the degree of difficulty of the procedure. No severe complication was observed; mean time to discharge was 31 (12) minutes. Time to discharge was not influenced by the difficulty of ERCP or by the total dose of propofol administered.Conclusions: A target-controlled infusion system for administration of propofol provides safe and effective sedation during ERCP. Further studies are needed to determine the cost-effectiveness and the safety profile for infusion of propofol with a target-controlled infusion system by a nonanesthesiologist during ERCP.

OBJECTIVE: A study was undertaken to compare the effectiveness of acupuncture in reducing patient's discomfort and anxiety during colonoscopy with a standard sedation protocol.METHODS: Thirty patients scheduled to undergo colonoscopy were randomly assigned to receive acupuncture, sham, or no acupuncture. A verbal rating scale was used to measure patient's pain when the endoscope reached four scheduled positions. Midazolam was administered at baseline and again anytime patients complained of "severe" pain. The amount of midazolam administered was recorded. A verbal rating scale was used to assess patient's satisfaction with the level of sedation achieved.RESULTS: Pain level was lower, although not significantly, in the acupuncture group. Midazolam boluses were required in three patients with acupuncture (30%), eight in the sham group (80%), and nine in the control group (90%) (p = 0.01). Six patients in the acupuncture group (60%) reported optimum acceptance of colonoscopy compared with only one in the sham group (10%) and none in the control group (90%) (p = 0.016). Satisfaction scores, assessed 24-72 h after colonoseopy, were extremely high (median score 90 of 100) in the three groups.CONCLUSIONS: Acupuncture may decrease the demand for sedative drugs during colonoseopy by reducing discomfort and anxiety of the patient and the well-known adverse effects of pharmacologic sedation. (Am J Gastroenterol 2003;98:312-316. (C) 2003 by Am. Coll. of Gastroenterology).

The aim of this retrospective study was to evaluate the influence of age on the outcome of liver resection. A total of 129 consecutive liver resections were divided into two groups: ≥ 70 years old [old group (O-group)] and < 70 years old [young group (Y-group)]. The two groups were first compared for the variables potentially affecting the postoperative course, including diagnosis, concomitant diseases, previous abdominal surgery, type of operation (major or minor resection), associated procedures, presence and length of portal clamping, intraoperative blood losses and transfusions, and length of operation. The outcome of liver resections was evaluated in terms of postoperative mortality, morbidity, transfusions, and length of hospitalization. The Y-group included 97 resections in 95 patients, aged 55.9 ± 10.5 years (mean ± SD; range: 23–69 years), and the O-group included 32 resections in 32 patients, aged 73.7 ± 3.2 years (mean ± SD; range: 70–82 years. The O-group included more hepatocellular carcinomas (46.9% versus 20.6%, p = 0.002) and cardiovascular diseases (15.2% versus 1.0%, p = 0.004). The two groups were comparable (p > 0.05) when evaluated for all other listed variables. As regards the postoperative outcome, the length of hospitalization was similar (median, range: 9.5 days, 5–60 days in the Y-group and 9 days, 5–48 days in the O-group) and the need for postoperative transfusions were not statistically different. Mortality included one case among young patients, while no deaths were recorded among elderly patients. Postoperative morbidity was higher in Y-group than in O-group (21.6% versus 9.4%, p = 0.2). In conclusion, the age factor does not negatively affect the outcome of liver resections.

STUDY OBJECTIVE:To compare the onset time and duration of epidural anesthesia, and the quality of postoperative analgesia produced by levobupivacaine, racemic bupivacaine, and ropivacaine. DESIGN:Prospective, randomized, double-blinded study. SETTING:Inpatient anesthesia at a University Hospital. PATIENTS:45 ASA physical status I, II, and III patients, undergoing elective total hip replacement. INTERVENTIONS:After standard intravenous midazolam premedication and infusion of 500 mL of Ringer's acetate solution, patients were randomly allocated to receive epidural block with 0.5% levobupivacaine (n = 15), 0.5% bupivacaine (n = 15), or 0.5% ropivacaine (n = 15). Postoperatively, after pinprick sensation recovered at T(t), a patient-controlled epidural infusion was provided with 0.125% levobupivacaine, 0.125% bupivacaine, or 0.2% ropivacaine, respectively (baseline infusion rate 5 mL/hr; incremental bolus 2 mL, lockout time: 20 min). Intravenous ketoprofen was also available for rescue analgesia if required. MEASUREMENTS AND MAIN RESULTS:The onset time of sensory block was 31 +/- 16 minutes with levobupivacaine, 25 +/- 19 minutes with bupivacaine, and 30 +/- 24 minutes with ropivacaine (p = 0.98), after a median (range) volume of 15 (10-18) mL in Group Levobupivacaine, 14 (10-18) mL in Group Bupivacaine, and 15 (10-18) mL in Group Ropivacaine (p = 0.85). Six patients in the ropivacaine group (40%) showed an intraoperative Bromage score <2 as compared with only three patients of Group Levobupivacaine (20%) and no patient of Group Bupivacaine (p = 0.02). Recovery of pinprick sensation at T(t) occurred after 214 +/- 61 minutes with levobupivacaine, 213 +/- 53 minutes with bupivacaine, and 233 +/- 34 minutes with ropivacaine (p = 0.26). A similar degree of pain relief was observed in the three groups without differences in local anesthetic consumption and need for rescue analgesia. Motor blockade progressively resolved without differences among the three groups. CONCLUSIONS:Levobupivacaine 0.5% produces an epidural block of similar onset, quality, and duration as the one produced by the same volume of 0.5% bupivacaine, with a motor block deeper than that produced by 0.5% ropivacaine. When prolonging the block for the first 12 hours after surgery with a patient-controlled epidural infusion, 0.125% levobupivacaine provides adequate pain relief after major orthopedic surgery, with similar recovery of motor function as compared with 0.125% bupivacaine and 0.2% ropivacaine.

UNLABELLED:We compared the onset time and quality of interscalene brachial plexus block produced with levobupivacaine and ropivacaine in 50 patients undergoing open shoulder surgery randomly allocated to receive 30 mL of 0.5% levobupivacaine (n = 25) or 0.5% ropivacaine (n = 25) injected through a 20-gauge catheter placed into the interscalene sheath using a 18-gauge insulated and stimulating Tuohy introducer. The block was also prolonged after surgery using a patient-controlled interscalene analgesia with 0.125% levobupivacaine or 0.2% ropivacaine, respectively (basal infusion rate, 6 mL/h; bolus, 2 mL; lockout period, 15 min; maximum boluses per hour, three). Three patients (two with levobupivacaine [8%] and one with ropivacaine [4%]) failed to achieve surgical block within 45 min after the injection and were excluded. The onset time of surgical block was 20 min (10-40 min) with levobupivacaine and 20 min (5-45 min) with ropivacaine (P = 0.53). Rescue intraoperative analgesia (0.1 mg of fentanyl IV) was required in eight patients in each group (34%) (P = 0.99). Forty-two patients completed the 24-h postoperative infusion (22 with levobupivacaine and 20 with ropivacaine). Postoperative analgesia was similarly effective in both groups. Total consumption of local anesthetic infused during the first 24 h was 147 mL (144-196 mL) with levobupivacaine and 162 mL (144-248 mL) with ropivacaine (P = 0.019), with a ratio between boluses received and requested of 0.8 (0.4-1.0) and 0.7 (0.4-1.0), respectively (P = 0.004). The degree of motor block of the operated limb was deeper with levobupivacaine than ropivacaine when starting postoperative analgesia; however, no further differences in degree of motor function were observed between the two groups. We conclude that 30 mL of levobupivacaine 0.5% induces an interscalene brachial plexus anesthesia of similar onset and intensity as the one produced by the same volume and concentration of ropivacaine. Postoperative interscalene analgesia with 0.125% levobupivacaine results in similar pain relief and recovery of motor function with less volume of local anesthetic than with 0.2% ropivacaine. IMPLICATIONS:This prospective, randomized, double-blinded study demonstrates that 30 mL of 0.5% levobupivacaine produces an interscalene brachial plexus block of similar onset and quality as the one produced by the same volume of 0.5% ropivacaine. When prolonging the block after surgery, 0.125% levobupivacaine provides adequate pain relief and recovery of motor function after open shoulder surgery, with less volume infused during the first 24 h after surgery than 0.2% ropivacaine.

In 1950 Rees and Gray [1] suggested a definition of general anesthesia that included narcosis, analgesia, and relaxation. Time has proved that the term analgesia is unsatisfactory. Analgesia means freedom from pain. In order for pain exist, a conscious patient must elaborate impulse from the periphery as pain. If the patient is unconscious, then he cannot be aware of pain, that is to say analgesia is present. Of course during surgery there are important reactions to reflex stimuli that during consciousness would be painful. Moving from these concepts, the same authors [1] proposed the most widely accepted triad of anesthesia, which includes narcosis, relaxation and reflex depression.

To compare intraoperative and postoperative clinical properties of levobupivacaine and ropivacaine for sciatic nerve block, 50 ASA physical status I and II. patients undergoing hallux valgus repair received a femoral nerve block with 15 mL of 2% mepivacaine. They were then randomly allocated in a double-blinded fashion to receive a sciatic nerve block with either 0.5% levobupivacaine (n = 25) or 0.5% ropivacaine (n = 23). An independent blinded observer evaluated the onset time of surgical anesthesia as well as the quality of the surgical block and postoperative analgesia. The median (range) onset time of surgical block at the sciatic nerve distribution was 30 min (5-60 min) with levobupivacaine and 15 min (5-60 min) with ropivacaine (P = 0.63). Four patients (two patients in each group) received a supplementary ankle block by the surgeon just before the beginning of surgery. All four patients also received IV fentanyl supplementation, but in three of them, propofol infusion was required to complete surgery (two in the Levobupivacaine group [8%] and one in the Ropivacaine group [4%]; P = 0.99). In six patients of the Levobupivacaine group (24%) and five patients of the Ropivacaine group (20%), IV fentanyl supplementation was required to complete surgery (P = 0.99). No differences in the time to recovery of sensory and motor function were observed between the two groups, whereas median (range) duration of postoperative analgesia was 16 h (8-24 h) with levobupivacaine and 16 h (8-24 h) with ropivacaine (P = 0.83). We conclude that 0.59% levobupivacaine and 0.5% ropivacaine provide comparable surgical anesthesia and postoperative analgesia.

Study Objective: To compare the intraoperative and postoperative clinical properties of the sciatic nerve block performed with either 0.5% bupivacaine or 0.5% levobupivacaine for orthopedic foot procedures.Design: Randomized, double-blind study.Setting: Inpatient unit of a university-affiliated hospital.Patients: 30 ASA physical status I and 11 patients undergoing elective hallux valgus repair under regional anesthesia.Interventions: After administering intravenous (IV) midazolam premedication (0.05 mg/kg), a femoral nerve block was performed with 15 mL of mepivacaine 2%. Patients were then randomly allocated to receive, in a double-blind fashion, a sciatic nerve block with 20 mL of either 0.5% bupivacaine (n = 15) or 0.5% levobupivacaine (n = 15).Measurements and Main Results: An observer who was blinded to the study drug recorded the onset time, quality, and duration of the sciatic nerve block. Postoperative analgesia consisted of 100 mg IV ketoprofen every 8 hours, with the first administration given at the patient's request. Mean (+/-SEM) onset time of the sciatic nerve block was 35 +/- 5 minutes for bupivacaine and 31 +/- 6 minutes for levobupivacaine (p = not significant [NS]). The duration of motor and sensory blocks with bupivacaine was 761 +/- 112 and 790 +/- 110 minutes, respectively, and 716 +/- 80 minutes and 814 +/- 73 minutes, respectively, with levobupivacaine (p = NS). The first pain medication was requested after 844 +/- 96 minutes with bupivacaine and 872 +/- 75 minutes after levobupivacaine (p = NS). No differences in the quality of nerve block and patient satisfaction were reported between the two groups.Conclusions: A dose of 20 mL of 0.5% levobupivacaine induces sciatic nerve block of similar onset, duration, and intensity as the block produced by the same volume and concentration of the racemic solution of bupivacaine. (C) 2002 by Elsevier Science Inc.

Background The authors studied the changes in selected hemostatic variables in patients undergoing coronary surgery with on-pump coronary artery bypass grafting (CABG) or off-pump coronary artery bypass surgery (OPCAB) techniques. Methods Platelet counts and plasma concentrations of antithrombin, fibrinogen, D dimer, alpha(2) antiplasmin, and plasminogen were measured preoperatively, 5 min after administration of heparin, 10 min after arrival in the intensive care unit, and 24 h after surgery in patients scheduled to undergo OPCAB (n = 15) or CABG (n = 15). To correct for dilution, hemostatic variables and platelet counts were adjusted for the changes in immunoglobulin G plasma concentrations and hematocrit, respectively. Results Adjusting for dilution, antithrombin and fibrinogen concentrations decreased to a similar extent in patients undergoing OPCAB or CABG (pooled means and 95% confidence limits of the mean: 95.5% of baseline, 93-98%, P = 0.002, and 91.7% of baseline, 88-95%, P = 0.0001), respectively, whereas alpha(2)-antiplasmin concentrations were unchanged. Only CABG was associated with a reduction in platelet counts (76% of baseline, 66-85%, P = 0.0001), plasminogen concentrations (96% of baseline, 91-99%, P = 0.011), and increased D-dimer formation (476%, 309-741%, P = 0.004). Twenty-four hours after surgery, platelet counts were still lower in patients undergoing CABG (P = 0.049), but all the investigated variables adjusted for dilution were similar in the two groups. Conclusions Coronary surgery causes a net consumption of antithrombin and fibrinogen. A transient decrease in platelet counts, with plasminogen activation and increased D-dimer formation, however, is only observed with CABG. Twenty-four hours after surgery, the hemostatic profiles of patients in both groups are similar.