Gianluca Cappelleri

Small-dose clonidine prolongs postoperative analgesia after sciatic-femoral nerve block with 0.75% ropivacaine for foot surgery.

To evaluate the effects of adding small-dose clonidine to 0.75% ropivacaine during peripheral nerve blocks, 30 ASA physical status I and II patients undergoing hallux valgus repair under combined sciatic-femoral nerve block were randomly allocated in a double-blinded fashion to receive block placement with 30 mL of either 0.75% ropivacaine alone (group Ropivacaine, n = 15) or 0.75% ropivacaine plus 1 &mgr;g/kg clonidine (group Ropivacaine-Clonidine, n = 15). Hemodynamic variables, oxygen saturation, and levels of sedation, as well as the time required to achieve surgical block and time to first analgesic request, were recorded by a blinded observer. Time to surgical blockade required 10 min in both groups. Patients in the Ropivacaine-Clonidine group were more sedated than patients in the Ropivacaine group only 10 min after block placement. No differences in oxygen saturation and hemodynamic variables, degree of pain measured at first analgesic request, and consumption of postoperative analgesics were observed between the two groups. The mean time from block placement to first request for pain medication was shorter in group Ropivacaine (13.7 h; 25th–75th percentiles: 11.8–14.5 h) than in group Ropivacaine-Clonidine (16.8 h; 25th–75th percentiles: 13.5–17.8 h) (P = 0.038). We conclude that adding 1 &mgr;g/kg clonidine to 0.75% ropivacaine provided a 3-h delay in first request for pain medication after hallux valgus repair, with no clinically relevant side effects. Implications This prospective, randomized, double-blinded study demonstrated that, when providing combined sciatic-femoral nerve block for hallux valgus repair, the addition of 1 &mgr;g/kg clonidine to 0.75% ropivacaine prolongs the duration of postoperative analgesia by 3 h, with only a slight and short-lived increase in the degree of sedation and no hemodynamic adverse effects.

Regional anaesthesia for outpatient knee arthroscopy: a randomized clinical comparison of two different anaesthetic techniques

Background: The purpose of this prospective, randomized study was to evaluate the time required to perform anaesthesia, achieve surgical block and fulfil standardized discharge criteria in outpatients receiving knee arthroscopy with either spinal anaesthesia or combined sciatic‐femoral nerve block.

The effects of the Single or Multiple injection technique on the onset time of femoral nerve blocks with 0.75% ropivacaine

UNLABELLED We evaluated the effect of the injection technique on the onset time and efficacy of femoral nerve block performed with 0.75% ropivacaine. A total of 30 patients undergoing arthroscopic knee surgery were randomly allocated to receive femoral nerve blockade with 0.75% ropivacaine by using either a single injection (Single group, n = 15) or multiple injection (Multiple group, n = 15). Nerve blocks were placed by using a short-beveled, Teflon-coated, stimulating needle. The stimulation frequency was set at 2 Hz, and the intensity of stimulating current, initially set at 1 mA, was gradually decreased to <0.5 mA after each muscular twitch was observed. In the Single group, 12 mL of 0.75% ropivacaine was slowly injected, as soon as the first muscular twitch was observed. In the Multiple group, the stimulating needle was inserted and redirected, eliciting each of the following muscular twitches: contraction of vastus medialis, vastus intermedius, and vastus lateralis. At each muscular twitch, 4 mL of the study solution was injected. Placing the block required 4.2 +/- 1.7 min (median, 5 min; range, 2-8 min) in the Multiple group and 3.4 +/- 2.2 min (median, 3 min; range, 1-5 min) in the Single group (P = 0.02). Onset of nerve block (complete loss of pinprick sensation in the femoral nerve distribution with concomitant inability to elevate the leg from the operating table with the hip flexed) required 10 +/- 3.7 min in the Multiple group (median, 10 min; range, 5-20 min) and 30 +/- 11 min in the Single group (median, 30 min; range, 10-50 min) (P < 0.0005). Propofol sedation was never required to complete surgery; although 0.1 mg fentanyl at trocar insertion was required in two patients of the Multiple group (13%) and nine patients of the Single group (60%) (P = 0.02). We conclude that searching for multiple muscular twitches shortened the onset time and improved the quality of femoral nerve block performed with small volumes of 0.75% ropivacaine. IMPLICATIONS This prospective, randomized, blinded study was conducted to evaluate the effect of searching for multiple muscular twitches when performing femoral nerve block with small volumes of 0. 75% ropivacaine. Our results demonstrated that multiple injections markedly shortened the onset time and improved the quality of nerve blockade. This technique-related effect must be carefully considered when different clinical studies evaluating the use of new local anesthetic solutions for peripheral nerve blocks are compared.

Effects of Spinal Needle Type on Lateral Distribution of 0.5% Hyperbaric Bupivacaine

To evaluate the influence of needle type on the lateral distribution of 0.5% hyperbaric bupivacaine, 30 patients undergoing lower limb surgery were placed in the lateral position with the side to be operated on dependent and underwent dural puncture by either a 25-gauge Whitacre (n = 15) or a 25-gauge Quincke (n = 15) spinal needle. The needle hole was turned toward the dependent side and 8 mg of 0.5% hyperbaric bupivacaine was injected over 30 s. The lateral position was maintained for 15 min while a blind observer recorded loss of pinprick sensation and degree of motor block on both the dependent and nondependent sides every 5 min until regression of motor block by 1[degree sign] on the dependent side. Thirty minutes after the patients were placed in the supine position, unilateral sensory block was observed in 10 patients in the Whitacre group (66%) and in 2 patients in the Quincke group (13%) (P < 0.05). No differences in the rate of unilateral motor block were observed (73% and 40% in Whitacre and Quincke groups, respectively). We conclude that when a small dose of 0.5% hyperbaric bupivacaine is injected slowly into patients in the lateral position for 15 min, the Whitacre spinal needle provides a more marked differential block of sensory nerve roots between dependent and nondependent sides compared with the Quincke needle. Implications: Because unilateral spinal anesthesia can be advantageous for lower limb surgery, we evaluated the influence of the Whitacre and Quincke spinal needle types on the lateral distribution of small-dose 0.5% hyperbaric bupivacaine injected slowly into adult patients. (Anesth Analg 1998;87:355-9)

Does continuous sciatic nerve block improve postoperative analgesia and early rehabilitation after total knee arthroplasty?: A prospective, randomized, double-blinded study

Introduction: The aim of this prospective, randomized, double-blind study was to evaluate whether continuous sciatic nerve block can improve postoperative pain relief and early rehabilitation compared with single-injection sciatic nerve block in patients undergoing total knee arthroplasty (TKA) and lumbar plexus block. Methods: After ethical committee approval and written informed consent, 38 patients with ASA physical status I to II were enrolled. The first group received continuous sciatic and continuous lumbar plexus blocks (group regional or R, n = 19), whereas the second group received a single sciatic nerve block followed by saline infusion through the sciatic catheter and continuous lumbar plexus block (group control or C, n = 19). We assessed morphine consumption, scores for visual analog scale for pain at rest (VASr), and during continuous passive motion (VASi during CPM) for 48 hours postoperatively. Effectiveness of early ambulation was also evaluated. Results: Scores for VASr and VASi during CPM, as well as morphine consumption, were significantly higher in group C than in group R (P < 0.01). Moreover, patients in group R showed earlier rehabilitation with more effective ambulation (P < 0.05). Conclusions: Continuous sciatic nerve block improves analgesia, decreases morphine request, and improves early rehabilitation compared with single-injection sciatic nerve block in patients undergoing TKA and lumbar plexus block.

Low dose hyperbaric bupivacaine for unilateral spinal anaesthesia.

PurposeTo evaluate the effects of hyperbaric bupivacaine concentration in producing unilateral spinal anaesthesia.MethodsWith Ethical Committee approval and written consent, 60 patients undergoing lower limb surgery were placed in the lateral position with the side to be operated on dependent. After durai puncture (25-gauge Whitacre spinal needle), the needle hole was turned toward the dependent side and patients were randomly assigned to receive 8 mg of either 0.5% (Group05%, n = 30) or 1% (Group1%, n = 30) hyperbaric bupivacaine. The lateral position was maintained for 15 min, while a blinded observer recorded loss of pinprick sensation and degree of motor block on both sides until two segment regression of sensory level on the dependent side.ResultsAt the end of the 15 min lateral position spinal anaesthesia was more frequently unilateral in Group0.5% (80%) than in Group1%(53%)(P < 0.05). However, 30 min after patients were turned supine, unilateral spinal anaesthesia decreased to 60% of cases in Group0.5% and 40% of cases in Group1%(P = NS). The maximum sensory level on the dependent side [T10(L1 − T2) in Group0.5% and T8 (T12 − T3) in Group1%], time to reach it [20 (5–30) min in Group0.5% and 25 (10–35) min in Group1%], and time to two segment regression of sensory level [80 (30–135) min in Group0.5% and 75 (20–135) min in Group1%] were similar in both groups.ConclusionHighly concentrated solutions of hyperbaric bupivacaine are not advantageous in obtaining a unilateral spinal anaesthesia, when a small anaesthetic dose is injected slowly through a Whitacre spinal needle.RésuméObjectifÉvaluer les effets de la concentration de bupivacaïne hyperbare dans la production d’une rachianesthésie unilatérale.MéthodeAprès avoir reçu l’approbation du Comité d’éthique et une autorisation écrite, 60 patients devant subir une chirurgie du membre inférieur ont été placés en position latérale, le site opératoire du côté déclive. Après la ponction de la dure-mère (aiguille rachidienne Whitacre de calibre 25), la perforation latérale de l’aiguille a été orientée vers le côté déclive et les patients ont été répartis au hasard afin de recevoir 8 mg de bupivacaïne hyperbare 0,5% (Groupe0.5%, n = 30) ou 1% (Groupe1% n = 30) La position latérale a été maintenue pendant 15 min pendant lesquelles un observateur impartial a enregistré la perte de sensation de piqûre et le degré de blocage moteur des deux côtés jusqu’à une régression de deux segments du niveau sensitif sur le côté déclive.RésultatsAprès ces 15 min en position latérale, la rachianesthésie était plus souvent unilatérale dans le Groupe0,5% (80 %) que dans le Groupe1%(53 %) (P < 0,05). Cependant, 30 minutes après que les patients ont été tournés en décubitus dorsal, la rachianesthésie unilatérale a diminué à 60 % dans le Groupe0,5% et à 40 % dans le Groupe1% (P = NS). Ont été similaires dans les deux groupes: le niveau sensitif maximal du côté déclive [T10 (L1-T2) dans le Groupe0,5% et T8 (T12-T3) dans le Groupe1%], le temps requis pour atteindre ce niveau [20 (5–30) min dans le Groupe0,5% et 25 (10–35) min dans le Groupe1%] et le temps pour que se produise une régression de deux segments du niveau sensitif [80 (30–135) min dans le Groupe0,5% et 75 (20–135) min dans le Groupe1%].ConclusionDes solutions très concentrées de bupivacaine hyperbare ne sont pas avantageuses pour obtenir une rachianesthésie unilatérale lorsqu’une faible dose d’anesthésique est injectée lentement au moyen d’une aiguille rachidienne Whitacre.

Randomized comparison of remifentanil-propofol with a sciatic-femoral nerve block for out-patient knee arthroscopy.

BACKGROUND AND OBJECTIVE To evaluate preparation and discharge times as well as the anaesthesia-related costs of out-patient knee arthroscopy performed with a combined sciatic-femoral nerve block, or a propofol-remifentanil general anaesthetic. METHODS With Ethics Committee approval and written informed consent, 40 healthy patients were pre-medicated with intravenous midazolam (0.05 mg kg(-1)) and ketoprofen (50 mg). They were then randomly allocated to receive either a combined sciatic-femoral nerve block with 25 mL mepivacaine 2% (15 mL for the femoral nerve, 10 mL for the sciatic nerve) (PNB group, n = 20), or a general anaesthetic with a continuous intravenous infusion of remifentanil (0.1-0.3 microgkg(-1) min(-1)) and propofol (target plasma concentration 2-4 microg mL(-1)) with a laryngeal mask airway (GA group, n = 20). RESULTS The median (range) preparation time was 16 (10-28)min in the PNB group and 13 (8-22)min in the GA group (P = 0.015). Ten PNB patients were directly discharged to the day-surgery unit after the procedure as compared with one GA patient (P = 0.003). Discharge from the postanaesthesia care unit (PACU) required 5 (5-20) min in the PNB group and 23 (7-95) min in the GA group (P = 0.001). Home discharge criteria were fulfilled after 277 (150-485) min in the PNB group and 170 (100-400) min in the GA group (P = 0.005). Costs related to the time spent in the PACU were lower for the PNB group (1.10 euro, range Euro 0-22 euro) compared with the GA group (30 euro, range 0-176 euro) (P = 0.0005). There were no differences in total costs: PNB group 158 euro (range 105-194 euro) versus GA group 160 euro (range 101-238 euro) (P = 0.61). CONCLUSIONS In patients undergoing out-patient knee arthroscopy, the length of stay in the PACU can be shorter after a sciatic-femoral nerve block with a small volume of mepivacaine 2% compared with a propofol-remifentanil anaesthetic, and there is an increased likelihood that they will bypass the first phase of the postoperative recovery.

Concentration anesthésique efficace minimale (CAEM) pour un bloc du nerf sciatique : approches sous-glutéale et poplitée

BackgroundWe tested the hypothesis that using a subgluteus approach to the sciatic nerve requires a lower concentration of mepivacaine to obtain complete anesthesia as compared with the popliteal approach.MethodsWith midazolam premedication (0.05 mg·kg-1 iv), 48 patients undergoing hallux valgus repair were randomly allocated to receive a sciatic nerve block using either a posterior popliteal (group Popliteal, n = 24) or subgluteus (group Subgluteus, n = 24) approach with 30 mL of local anesthetic injected after elicitation of plantar flexion of the foot with a current ≤ 0.5 mA. A 20G catheter was inserted for 2–4 cm to supplement the block if required. The concentration of the injected solution was varied for consecutive patients using the up-and-down staircase method according to the response of the previous patient (initial concentration: 1%; up-and-down steps: 0.1 %). Successful nerve block was defined as complete loss of pinprick sensation in both tibial and common peroneal nerve distributions with concomitant inability to perform plantar or dorsal flexion of the foot 30 min after injection.ResultsThe minimum effective anesthetic concentration of mepivacaine resulting in complete block of the sciatic nerve in 50% of cases (ED50) was 0.95% ± 0.014% (95% confidence intervals [CI95]: 0.77%-1. 12%) in group Subgluteus and 1.53% ± 0.453% (CI95: 0.96%-2.00%) in group Popliteal (P = 0.026). The ED95 for adequate nerve block calculated with probit transformation and logistic regression analysis was 1.12% (CI95: 0.71%-1.99%) in group Subgluteus and 1.98% (CI95: 1.39%-2.31 %) in group Popliteal.ConclusionA subgluteus approach to the sciatic nerve facilitates a reduction of the minimum effective concentration of local anesthetic required to produce an effective surgical block within 30 min after the injection as compared with the posterior popliteal approach.RésuméContexteNous avons testé l’hypothèse qu’une concentration plus faible de mépivacaïne est nécessaire pour obtenir une anesthésie complète avec une approche sous-glutéale qu’avec une approche poplitée lors d’un bloc du nerf sciatique.MéthodeQuarante-huit patients devant subir une réparation d’hallux valgus et ayant reçu du midazolam en prémédication (0,05 mg·kg-1 iv) ont été randomisés en deux groupes. Le bloc du nerf sciatique a été réalisé par une approche poplitée postérieure dans le premier groupe (groupe poplité, n = 24) et dans le second par une approche sous-glutéale (groupe sous-glutéal, n = 24) à l’aide de 30 mL d’anesthésique local injecté après élicitation de la flexion plantaire du pied avec un courant de ≤ 0,5 mA. Un cathéter de 20G a été inséré à 2–4 cm afin de compléter le bloc si nécessaire. Nous avons varié la concentration de solution injectée chez les patients consécutifs selon la méthode d’estimation par accroissement ou diminution, et ce selon la réaction du patient précédent (concentration initiale : 1 %; accroissement ou diminution : 0,1 %). Un bloc nerveux réussi était défini comme la perte complète de sensibilité à la douleur dans les distributions des nerfs tibial et péroné commun avec une incapacité concomitante à bouger le pied (flexion plantaire ou dorsale) 30 min après l’injection.RésultatsLa concentration anesthésique efficace minimale de mépivacaïne ayant pour résultat un bloc complet du nerf sciatique était, dans 50 % des cas (ED50), de 0,95 % ± 0,014 % (95 % intervalle de confiance [IC95]: 0,77 %-1,12 %) dans le groupe sous-glutéal et de 1,53 % ± 0,453 % (IC95: 0,96 %-2,00 %) dans le groupe poplité (P = 0.026). La ED95 pour un bloc nerveux adéquat, calculé avec la transformation de probit et une analyse de régression logistique était de 1,12 % (IC95: 0,71 %-1,99 %) dans le groupe sous-glutéal et de 1,98 % (IC95: 1,39 %-2,31 %) dans le groupe poplité.ConclusionComparée à l’approche poplitée postérieure, l’approche sous-glutéale du nerf sciatique facilite une réduction de la concentration minimale efficace d’anesthésiques locaux nécessaire à la réalisation d’un bloc chirurgical efficace 30 min après injection.Contexte Nous avons teste l’hypothese qu’une concentration plus faible de mepivacaine est necessaire pour obtenir une anesthesie complete avec une approche sous-gluteale qu’avec une approche poplitee lors d’un bloc du nerf sciatique.

The pressor response after laryngeal mask or cuffed oropharyngeal airway insertion

Background: Since the cuffed oropharyngeal airway (COPA) has been suggested to cause less pharyngeal trauma than the laryngeal mask airway (LMA), we conducted a prospective, randomised study to compare haemodynamic changes after placing either the COPA or LMA in healthy anaesthetised adults.

Letter by Ruggieri et al Regarding Article, “Randomized Comparison of Sevoflurane Versus Propofol to Reduce Perioperative Myocardial Ischemia in Patients Undergoing Noncardiac Surgery”

To the Editor: Adverse cardiac events are a major cause of morbidity and mortality after noncardiac surgery. Prevention of cardiac risk events is one of the most important tenets of anesthetic practice.1–3 We read with great interest the article by Lurati Buse1 on Randomized Comparison of Sevoflurane Versus Propofol to Reduce Perioperative Myocardial Ischemia in Patients Undergoing Noncardiac Surgery. In their article the authors recorded continuous ECG for 48 hours perioperatively, measured troponin T and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) on postoperative days 1 and 2 strictly in accordance with the study protocol. They compared the incidence of postoperative …