Guido Fanelli

A Double-Blind Comparison of Ropivacaine, Bupivacaine, and Mepivacaine During Sciatic and Femoral Nerve Blockade

No study has evaluated the efficacy of ropivacaine in peripheral nerve block of the lower extremity.The purpose of this prospective, randomized, double-blind study was to compare ropivacaine, bupivacaine, and mepivacaine during combined sciatic-femoral nerve block. Forty-five ASA physical status I or II patients scheduled for elective hallux valgus repair with thigh tourniquet were randomized to receive combined sciatic-femoral block with 0.75% ropivacaine (ROPI, n = 15), 0.5% bupivacaine (BUPI, n = 15), and 2% mepivacaine (MEPI, n = 15). Time required for onset of sensory and motor block on the operated limb (readiness for surgery) and resolution of motor block, as well as onset of postsurgical pain and time of first analgesic requirement, were recorded. The three groups were similar with regard to demographic variables, duration of surgery, and measured visual analog pain scores. Onset of sensory and motor blockade was similar in Groups ROPI and MEPI and significantly shorter than in Group BUPI (P = 0.002 and P = 0.001, respectively). Resolution of motor block occurred later in Groups ROPI and BUPI than in Group MEPI (P = 0.005 and P = 0.0001, respectively). Duration of postoperative analgesia was significantly longer in Groups ROPI (670 +/- 227 min) and BUPI (880 +/- 312 min) compared with Group MEPI (251 +/- 47 min) (P = 0.0001), with a significant decrease in postoperative pain medication requirements (P < 0.05). We conclude that for sciatic-femoral nerve block, 0.75% ropivacaine has an onset similar to that of 2% mepivacaine and a duration of postoperative analgesia between that of 0.5% bupivacaine and 2% mepivacaine. Implications: Quick onset of block with prolonged postoperative analgesia is an important goal in peripheral nerve blockade. We evaluated the clinical properties of 0.5% bupivacaine, 2% mepivacaine, and 0.75% ropivacaine for sciatic-femoral nerve block and demonstrated that ropivacaine has an onset similar to that of mepivacaine but allows for postoperative analgesia between that of bupivacaine and mepivacaine. (Anesth Analg 1998;87:597-600)

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.

Unilateral bupivacaine spinal anesthesia for outpatient knee arthroscopy

Purpose: To compare unilateral and conventional bilateral bupivacaine spinal block in outpatients undergoing knee arthroscopy.Methods: One hundred healthy, premedicated patients randomly received conventional bilateral (n=50) or unilateral (n=50) spinal anesthesia with 8 mg hyperbaric bupivacaine 0.5%. A lateral decubitus position after spinal injection was maintained in unilateral group for 15 min. Times from spinal injection to readiness for surgery, block resolution, and home discharge were recorded.Results: Three patients in each group were excluded due to failed block. Readiness for surgery required 13 min (5 – 25 min) with bilateral and 16 min (15 – 30) with unilateral spinal block (P=0.0005). Sensory and motor blocks on the operated limb were T9 (T12 – T2) with a Bromage score 0/1/2/3: 0/2/0/45 in the unilateral group and T7 (T12 – T1) with Bromage score 0/1/2/3: 4/1/6/36 with bilateral block (P=0.026 andP=0.016, respectively). Vasopressor was required only in five bilateral patients (P=0.02). Two segment regression of sensory level and home discharge required 81±25 min and 281±83 min with bilateral block, and 99±28 min and 264±95 min with unilateral block (P=0.002 andP=0.90, respectively).Conclusion: Seeking unilateral distribution of spinal anesthesia provided more profound and longer lasting block in the operated limb, less cardiovascular effects, and similar home discharge compared with bilateral spinal anesthesia, with only a slight delay in preparation time.RésuméObjectif: Comparer le bloc rachidien unilatéral au bloc bilatéral traditionnel chez des patients ambulatoires qui subissent une arthroscopie du genou.Méthode: Cent patients sains ont reçu une prémédication et, de façon aléatoire, une rachianesthésie bilatérale traditionnelle (n=50) ou unilatérale (n=50) avec 8 mg de bupivacaïne hyperbare à 0,5 %. Après l’injection, les patients du groupe unilatéral ont été maintenus en décubitus latéral pendant 15 min. On a enregistré: le temps écoulé entre l’injection et le début de l’opération, le temps écoulé entre l’injection et le début de l’opération, le temps nécessaire à la résolution du bloc et le moment de la sortie du service.Résultats: Trois patients ont été exclus dans chaque groupe à cause de l’échec du bloc. II a fallu 13 min (5 – 25 min) de préparation à l’opération avec le bloc bilatéral et 16 min (15 – 30) avec le bloc unilatéral (P=0,0005). Les blocs sensitif et moteur sur le membre opéré ont été de T9 (T12 – T2) avec des scores de 0/1/2/3: 0/2/0/45 à l’échelle de Bromage dans le groupe unilatéral et de T7 (T12 – T1) et des scores de Bromage de 0/1/2/3: 4/1/6/36 avec le bloc bilatéral (P=0,026 et P=0,016, respectivement). Des vasopressures ont été nécessaires chez cinq patients seulement du groupe bilatéral (P=0,02). Le temps nécessaire à la régression de deux segments du bloc sensitif et au congé a été de 81±25 min et de 281±83 min avec le bloc bilatéral, et de 99±28 min et 264 ±95 min avec le bloc unilatéral (P=0,002 et P=0,90, respectivement).Conclusion: La rachianesthésie unilatérale, comparée à la rachianesthésie bilatérale, produit un bloc plus profond et plus long dans le membre opéré, moins d’effets cardiovasculaires, un séjour hospitalier de durée similaire et seulement un léger délai de préparation à l’intervention.

Frequency of hypotension during conventional or asymmetric hyperbaric spinal block

BACKGROUND AND OBJECTIVES The purpose of this randomized, double-blind study was to evaluate if use of an asymmetric spinal block affects the incidence of hypotension during spinal anesthesia. METHODS With Ethical Committee approval and patient consent, 120 patients undergoing lower limb surgery were placed in the lateral position with the side to be operated on dependent, and received 8 mg 0.5% hyperbaric bupivacaine through a 25-gauge Whitacre spinal needle. Patients were randomized to one of two groups: (a) local anesthetic was injected with barbotage through a cranially directed needle orifice, then patients were immediately turned to supine (conventional, n = 60); (b) local anesthetic was injected without barbotage with the needle orifice turned toward the dependent side, then the lateral position was maintained for 15 minutes (unilateral, n = 60). A blind observer recorded noninvasive hemodynamic variables, as well as loss of cold and pinprick sensation and motor block on both sides. RESULTS In the unilateral group, 31 patients (52%) showed a unilateral loss of cold sensation and 48 patients (80%) had no motor block on the nondependent side for the duration of the study, whereas all conventional patients had bilateral distribution of spinal block (P < .0001). The onset time and two-segment regression of sensory block on the dependent side were more rapid in the conventional group (18 +/- 7 minutes and 60 +/- 18 minutes) than in the unilateral group (22 +/- 8 minutes and 67 +/- 19 minutes) (P < .05 and P < .05, respectively). The incidence of hypotension (SAP decrease >30% from baseline) was higher in the conventional (22.4%) than unilateral group (5%) (P < .01). The maximum percentage changes from baseline values of systolic arterial blood pressure and heart rate were greater in conventional group (-28% +/- 16% and -19% +/- 10%) than in unilateral group (-8% +/- 16% and -12% +/- 18%) (P < .0001 and P < .01, respectively). CONCLUSIONS Achieving an asymmetric distribution of spinal block by injecting a small dose of 0.5% hyperbaric bupivacaine through a Whitacre spinal needle into patients placed in the lateral position for 15 min reduces the incidence of hypotension during spinal anesthesia.

Monitoring cerebral oxygen saturation in elderly patients undergoing general abdominal surgery: a prospective cohort study

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 ≥ 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.

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.

Intraoperative epidural anesthesia and postoperative analgesia with levobupivacaine for major orthopedic surgery: a double-blind, randomized comparison of racemic bupivacaine and ropivacaine ☆

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 Ringers 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.

Clinical assessment of target-controlled infusion of propofol during monitored anesthesia care

PurposeTo determine the plasma concentrations of propofol required to achieve different levels of sedation during monitored anesthesia care.MethodsSixty ASA 1-11, 18–65 yr-old patients, received a target-controlled continuousiv infusion of propofol. The target plasma concentration of propofol (Cpt) was initially set at 0.4 μ·g·ml−1. Two minutes after calculated equilibrium between plasma and effect-site concentrations, the Cpt of propofol was increased by 0.2 μg·ml−1 steps until the patient showed no reaction to squeezing the trapezius. The level of sedation was assessed immediately before each increase in propofol Cpt using the Observer’s Assessment of Alertness/Sedation (OAA/S) scale.ResultsThe Cpt of propofol required to induce lethargic response to name was 1.3 μg·ml−1 (5° and 95° percentiles: 1.0 – 1.8 μg·ml−1), to obtain response after loud and repeated calling name was 1.7 μg·ml−1 (1.2 – 2.2 μg·ml−1), to obtain response after prodding or shaking was 2.0 μg·ml−1(1.6 – 2.6 μg·ml−1), to obtain response after squeezing the trapezius was 2.4 μg·ml−1 (1.8 – 3.0 μg·ml−1). Patients showed no response after squeezing the trapezius at 2.8 μg·ml−1 (2.0 – 3.6 μg·ml−1). Correlation between Cpt propofol and sedation scores were r =0.76, P< 0.0001.ConclusionsTarget-controlled infusion of propofol provided easy and safe management of intraoperative sedation, allowing fast and predictable deepening in the level of sedation, while minimizing systemic side effects of intravenous sedation due to the minimal risk of overdosing the drug.RésuméObjectifDéterminer les concentrations plasmatiques de propofol nécessaire pour fournir différents niveaux de sédation monitorés.MéthodeSoixante patients ASA 1–11 de 18–65 ans ont reçu une perfusion continue de propofoliv à cible contrôlée. La concentration plasmatique ciblée de propofol (Cpc) était d’abord de 0,4 μg·ml−1. Deux minutes après avoir atteint l’équilibre entre la concentration plasmatique et celle du site d’effet, la Cpc de propofol a été augmenté par paliers de 0,2μg·ml−1 jusqu’à ce que le patient ne réagisse plus à une pression sur le trapèze. Le niveau de sédation a été évalué immédiatement avant chaque augmentation de la Cpc de propofol à l’aide de l’échelle de cotation de la vigilance par l’observateur/sédation (CVO/S).RésultatsLa Cpc de propofol nécessaire pour induire une réaction léthargique du patient à l’appel de son nom était de 1,3 μg·ml−1(5° et 95° percentiles: 1,0 – 1,8 μg · ml−1, pour obtenir une réaction après l’appel du nom répété et à voix forte était de 1,7 μg·ml−1 (1,2–2,2 μg·ml−1), pour réagir à une poussée ou une secousse, 2.0 μg·ml−1 (1.6 -2.6μg·ml−1), et pour réagir à une pression sur le trapèze, 2,4μg·ml−1 (1,8 – 3,0μg·ml−1). Les patients n’ont pas réagi à la pression sur le trapèze avec une concentration de 2,8 μg·ml−1 (2,0 – 3,6μg·ml−1). La corrélation entre la Cpc de propofol et les niveaux de sédation a été aussi observée, r = 0,76, P < 0,0001.ConclusionLa perfusion de propofol à cible contrôlée fournit une ligne de conduite facile et sûre pour la sédation peropératoire, permettant l’approfondissement rapide et prévisible de la sédation tout en réduisant les effets secondaires généraux de la sédation intraveineuse causés par le risque minimal d’une surdose de médicament.

Cardiovascular effects of two different regional anaesthetic techniques for unilateral leg surgery

Background: Cardiovascular function was assessed in 20 ASA I‐II patients, scheduled for elective orthopaedic surgery with tourniquet in order to compare the haemodynamic changes induced by unilateral spinal anaesthesia and combined sciaticofemoral 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.