Herve Bouaziz

Comparison Between Conventional Axillary Block and a New Approach at the Midhumeral Level

We undertook this prospective, randomized study to compare the success rate, time spent performing the blocks, onset time of surgical anesthesia, presence of complete motor blockade, and lidocaine plasma concentrations between conventional axillary block and a new approach at the midhumeral level.Both techniques were performed using a peripheral nerve stimulator. Two nerves were located at the axillary crease, whereas four nerves were located at the midhumeral level. Sixty patients undergoing upper limb surgery were assigned to one of the two techniques. The sensory block was evaluated before surgery for all of the distributions of the four major nerves of the upper extremity. A subset of patients had lidocaine plasma concentrations determined. Times to perform the blocks, mean maximum plasma lidocaine concentration, and time to peak concentration were not different between groups. The success rate of the block, as well as the incidence of complete motor blockade, was greater with the midhumeral approach compared with the axillary approach. However, the onset time to complete anesthesia of the upper extremity was shorter in the axillary approach. For brachial plexus anesthesia, we conclude that the midhumeral approach provided a greater success rate than the traditional axillary approach. (Anesth Analg 1997;84:1058-62)

Lateral approach to the sciatic nerve in the popliteal fossa.

We describe a modification of the sciatic nerve (SN) block in the popliteal fossa through the lateral approach.After a brief anatomic study using previously reported landmarks, we propose a new needle orientation associated with a double injection technique after identification of the tibial and the common peroneal nerve. Thirty-four patients undergoing ankle or foot surgery were enrolled in this study. With patients in the supine position, the upper edge of the patella and the groove between the posterior border of the vastus lateralis and the anterior border of the tendon of the biceps femoris were identified. The needle was directed posteriorly with a 20-30[degree sign] angle relative to the horizontal plane and slightly caudal. Both nerves were individually located with a nerve stimulator and blocked with a mixture of lidocaine-bupivacaine and clonidine. In all but one case, the two nerves were easily located, and no vascular puncture was evident. Effective analgesia was obtained for a minimum of 15 h (first analgesic demand). We conclude that this technique, with a modified direction of the needle and a double stimulation, provides a very high rate of success for SN blockade in the popliteal fossa. Implications: We describe a new lateral approach to the sciatic nerve in the popliteal fossa. The needle was directed caudad and posteriorly while seeking with a nerve stimulator for the tibial and the peroneal nerves, which were blocked separately. This technique was very successful. (Anesth Analg 1998;87:79-82)

Intravenous nitroglycerin to relieve intrapartum fetal distress related to uterine hyperactivity : A prospective observational study

During a 1-yr period, we evaluated prospectively the use of nitroglycerin (NTG) to relieve severe intrapartum fetal distress related to uterine hyperactivity. Sixty to ninety micrograms of NTG were injected intravenously (IV) within 2-5 min after onset of severe fetal distress after oxygen administration, left lateral decubitus, and discontinuation of any ongoing oxytocin infusion (62%) had failed to resolve the fetal heart rate abnormality. A second dose (60 or 90 micro g) was used 2-3 min later as required. NTG was completely effective in 22 cases (fetal distress resolution within 4-5 min with restoration of normal uterine activity) and partially but sufficiently effective in the remaining 2 cases (fetal distress resolution within 4-5 min with residual mild uterine hyperactivity). However, a second dose was required for nine parturients (38%). Six parturients (25%) developed hypotension 2 min after the first NTG injection, with a mean nadir of 93.2 mm Hg (minimum 85 mm Hg). Hypotension was always rapidly reversed with a small single dose of ephedrine (4.5-6 mg). In conclusion, we found small doses (60-180 micro g) of IV NTG to be associated with resolution of severe fetal distress related to uterine hyperactivity along with negligible side effects. (Anesth Analg 1997;84:1117-20)

The Effect of Adding a Minidose of Clonidine to Intrathecal Sufentanil for Labor Analgesia

Background Preliminary studies have suggested that the addition of clonidine to intrathecal sufentanil prolongs analgesia without producing motor blockade. Methods Fifty-three nulliparous women in painful labor were included in this prospective, randomized, double-blinded study. Parturients at 2- to 5-cm cervical dilation received either 5 [micro sign]g sufentanil plus 30 [micro sign]g clonidine or 5 [micro sign]g sufentanil intrathecally, followed by 5 mg bupivacaine epidurally. The primary outcome was time until first request for additional analgesia. Visual analog pain scores, sensory changes, blood pressure, heart rate, ephedrine requirements, motor blockade, sedation, pruritus, and nausea were also recorded. Results All parturients but one had effective analgesia in both groups, with similar sensory levels never exceeding T2. The duration (mean +/- SD) of analgesia was longer in the sufentanil - clonidine group: 125 +/- 46 versus 97 +/- 30 min (P = 0.007). The incidence of hypotension and the ephedrine requirements (median with range) were higher in the sufentanil - clonidine group: 63% versus 12% (P < 0.001) and 7.5 mg [range, 0 - 25.5 mg] versus 0 mg [range, 0 - 6 mg] (P < 0.0001). The incidence of fetal heart rate abnormalities during the first 30 min after intrathecal injection was similar in both groups (17% vs. 19%). No parturient had motor blockade. Conclusions The addition of 30 [micro sign]g clonidine to 5 [micro sign]g intrathecal sufentanil extended the duration of labor analgesia without producing motor blockade. However, as previously reported with 100 - 200 [micro sign]g clonidine, the incidence of hypotension and the ephedrine requirements were also increased, even when 30 [micro sign]g clonidine only was added.

The use of a selective axillary nerve block for outpatient hand surgery

Although no guidelines concerning discharge criteria after axillary plexus block are available, many institutions consider recovery of motor function as a critical factor.With the midhumeral approach, the four main nerves of the upper extremity can be blocked separately using a peripheral nerve stimulator. The aim of this double-blind study was to block the radial (R) and musculocutaneous (MC) nerves with lidocaine, and the median (M) and ulnar (U) nerves with bupivacaine to recover motor function of the elbow and wrist more rapidly while maintaining long-lasting postoperative analgesia at the operative site. Patients undergoing surgery for Dupuytrens contracture were randomized into two groups in a double-blind fashion: in the control group (n = 17), each of the four nerves was infiltrated with 10 mL of a mixture of 2% lidocaine and 0.5% bupivacaine, whereas in the selective group (n = 17), the R and MC nerves were blocked with 10 mL of 2% lidocaine each and the M and U nerves were blocked with 10 mL of 0.5% bupivacaine each. Recovery of motor block was significantly faster in the selective group (231 +/- 91 vs 466 +/- 154 min). However, time to first sensation of pain was not different between groups (707 +/- 274 vs 706 +/- 291 min). In conclusion, this new approach at the midhumeral level enables the anesthesiologist to selectively administer local anesthetics on different nerves. Implications: In outpatients undergoing surgery for Dupuytrens contracture, a midhumeral block was used with the musculocutaneous and radial nerves blocked by lidocaine and the median and ulnar nerves blocked with bupivacaine. Recovery of motor function and time to discharge were shorter compared with patients who received the mixture on all four nerves. (Anesth Analg 1998;86:746-8)

Audit of ketoprofen prescribing after orthopedic and general surgery

PurposeIn 1994, we developed a practice guideline which stated that ketoprofen should be used in every adult patient after surgical procedures for which at least moderate pain was anticipated. The dose recommended was 50 mg every six hours iv in the operating room followed by oral administration as soon as possible for three days. The purpose of this study was to evaluate the success of the guideline implementation.MethodsIn 1995, an audit performed by a research pharmacist assistant under the supervision of the authors analysed prospectively the files of patients scheduled for orthopedic or general surgery during a one-month period. The compliance of the nurses was also recorded.ResultsOf 185 patients operated upon during the period, seven were transferred to the ICU and were not evaluated. Ketoprofen was not prescribed to 112 (63%) of the 177 remaining patients, either because minor pain was expected (n = 55) or because one or several contra-indications to its use were detected. In cases where ketoprofen was used although theoretically contraindicated (11%), review of the medical records and interviews of anesthesiologists showed that prescription was guided by a risk/benefit analysis. In 18% of cases, nurses did not administer at least one dose of ketoprofen although medical prescription requested regular administration.ConclusionAlthough the use of NSAIDs is still controversial, implementation by anesthesiologists of a practice guideline introducing ketoprofen for postoperative analgesia was successful and the nursing non-compliance rate to follow written orders was modest.RésuméObjectifEn 1994, nous avons instauré des recommandations de pratique clinique (RPC) concernant la douleur post-opératoire qui incluaient des directives sur le kétoprofène: l’administration de kétoprofène (50 mg·6 heures) devait être systématique pour tout opéré chez lequel une douleur au moins modérée était prévue. L’administration intraveineuse devait être relayée par la voie orale dès que possible pour une durée totale de 3 jours. Le but de cette étude était de savoir si cet antalgique était bien prescrit (audit des pratiques médicales) et bien administré (audit des pratiques infirmières).MéthodeEn 1995, un audit réalisé par un pharmacien assistant de recherche supervisé par les auteurs a étudié prospectivement tous les dossiers des patients opérés de chirurgie abdominale ou orthopédique pendant un mois.RésultatsParmi les 185 patients, 7 n’ont pas été étudie car ils ont été transférés en réanimation avec ventilation post-opératoire. Le kétoprofène n’a pas été prescrit chez 112 patients (63 %) soit parce qu’une douleur mineure était attendue (n = 55) soit parce qu’une contre-indication avait été détectée. Dans 11 % des cas, le kétoprofène avait été utilisé bien que théoriquement contre-indiqué. Dans tous ces cas, l’analyse du dossier avec le praticien suggérait un rapport risque/bénéfice acceptable. L’adhésion des infirmères était bonne avec la nonadministration d’au moins une dose chez 18 % des patients.ConclusionLa mise en oeuvre de ces RPC a été un succès et bien que l’emploi des AINS soit controversé, ces produits sont bien prescrits et l’adhésion des infirmières est satisfaisante.

Transition from intrathecal analgesia to epidural anesthesia for emergency cesarean section using a combined spinal epidural technique.

Radiographic examination revealed flattening of vertebral bodies at all levels, widening of the epiphysis of long bones, and agenesis of the neck of femur. Echocardiography showed no abnormality. The patient received no premeditation. Intraoperative monitoring included electrocardiogram, noninvasive blood pressure, pulse oximetry, ETco, temperature, and neuromuscular blockade with train-of-four stimulation. Anesthesia was induced with 0, N,O, and halothane. After demonstrating that the lungs were easily ventilated with bag and mask, atracurium 5 mg was given to facilitate endotracheal intubation. Due care was taken to prevent any excessive extension of the neck. Laryngoscopy revealed partial exposure of the glottis, but with cricoid pressure a 5-mm endotracheal tube was passed in a single attempt. Ventilation was controlled and anesthesia was maintained with meperidine 5 mg intravenously, halothane 0.5%, and intermittent doses of atracurium. Surgery proceeded uneventfully for 70 min. On the operating table, flexion, extension, and rotation of the head was confined to an absolute minimum. In spite of generalized muscle hypotonia, the patient’s response to atracurium was normal. At the end of surgery, neuromuscular blockade was reversed and the trachea extubated. The patient made an uneventful recovery and was discharged on the fifth postoperative day. SDC is a rare autosomal dominent genetic disorder (1). There are only two previous reports on the anesthetic management of this disorder, one of which used regional anesthesia (23). The important possible anesthetic complications of this rare disorder are a high risk of atlantoaxial dislocation and compression of the spinal cord at Cl-2 during tracheal intubation (1). The facial manifestation of this syndrome may make laryngoscopic exposure of the vocal cords difficult. Obtaining a good mask airway may be difficult owing to a poor seal from facial asymmetry and the small chin. These patients may also have laryngotracheal stenosis (3). For a dwarf, of course, the appropriate endotracheal tube size will be smaller than that suggested for the patient’s age. Associated kyphoscoliosis with thoracic dysplasia may lead to respiratory failure in the perioperative period (2).

Regional anaesthesia and reactive airway disease

R E F E R E N C E S 1 Morikawa H, Mima H, Fujita I-I, Mishima S. Oxygen embolism due to hydrogen peroxide irrigation during cervical spinal surgery. Can J Anaesth 1995, 42: 231-3. 2 SaissyJM, Guignard B, Pats B, Lenoir B, Rouvier B. Risks of hydrogen peroxide irrigation in military surgery. (French) Ann Fr Anesth Reanim 1994; 13: 749-53. 3 Ferrari M, Catena S, Ferrari F, Bianchi R, Villani A. Severe pulmonary gas embolism caused by intraoperafive administration of hydrogen peroxide. (Italian) Minerva Anesthesiol 1994; 60: 403-6. 4 WilliamsonJ, WebbR, Russell W, Runciman W. The Australian Incident monitoring study. Air embolism an analysis of 2000 incident reports. Anaesth Intensive Care 1993; 21: 638-41.