S. Kapral

Postoperative pain and subcutaneous oxygen tension

Surgical patients randomly assigned to standard pain control had postoperative subcutaneous oxygen partial pressures that were significantly less than patients given better pain treatment. Our data suggest that control of postoperative pain is a major determinant of surgical-wound infection and should be given the same consideration as maintaining adequate vascular volume and normothermia.

Clonidine as adjuvant for mepivacaine, ropivacaine and bupivacaine in axillary, perivascular brachial plexus block.

PurposeTo evaluate the effects of clonidine on three local anesthetics (mepivacaine 1%, ropivacaine 0.75% and bupivacaine 0.5%) with comparable potency and almost the same concentration-response relationship.MethodsOne hundred and twenty trauma-patients were randomly allocated into six groups. In the control-groups (Mo/Ro/Ro/Bo) brachial plexus was performed using 40 mL of local anesthetic plus I mL of NaCL 0.9%. In the clonidine-groups (Mc/Rc/Bc) brachial plexus was performed using each 40 mL of drug plus I mL (0.150 mg) of clonidine. Onset-time and the duration of the sensory block were recorded. Data are expressed as mean ± SD.ResultsAccording to the average sensory block determined by a visual analog scale in the median, ulnar and radial nerve distributions and ranging from 100 (no sensory blockade) to 0 (complete sensory blockade), both mepi-groups showed a rapid onset (at 10 min: —Mo 20 ± 15 /Mc 19 ± 14; at 30 min: -Mo 3 ± 4 /Mc 5 ± 4). The ropi and bupi-groups both had a longer onset time (at 10 min:-Ro 23 ± 19I Re 25 ± 22 /Bo 24 ± 15; at 30 min -Ro / 0 ± 6/ Rc 11 ± 6 /Bo 12 ± 4). The onset time in group-Bc was significantly prolonged (at 10 min: −45 ± 21; at 30 min: −20 ± 6). Duration of motor blockade was prolonged by clonidine only in the mepivacaine and bupivacaine groups; (in minutes:Mo 212 ± 47 -Mc 468 ± 62;Ro 702 ± 52-Rc 712 ± 82;Bo 728 ± 36-Bc 972 ± 72).ConclusionThe present study shows that the addition of clonidine has a different impact on each of the three local anesthetics investigated in terms of onset and duration of block.RésuméObjectifÉvaluer les effets de la clonidine sur trois anesthésiques locaux à puissance comparable (la mépivacaïne à 1 %, la ropivacaïne à 0,75% et la bupivacaïne à 0,5%) qui présentent une relation concentration-réponse presque similaire.MéthodeCent vingt patients victimes de traumatisme ont été répartis au hasard en six groupes. Dans les groupes témoins (Mo/Ro/Bo), le bloc du plexus brachial comprenait 40 mL d’anesthésique local plus I mL de NaCL à 0,9%. Dans les groupes clonidine (Mc/Rc/Bc), il comprenait 40 mL d’anesthésique local plus I mL (0,150 mg) de clonidine. Le délai d’installation et la durée du blocage sensitif ont été notés et exprimés comme la moyenne ± l’écart type.RésultatsD’après le bloc sensitif moyen, déterminé par une échelle visuelle analogique appliquée aux distributions des nerfs médian, cubital et radial et qui s’étend de 100 (aucune anesthésie) à 0 (blocage sensitif complet), les deux groupes de mépivacaïne ont indiqué une installation rapide (à 10min: — Mo 20 ± 151 Mc 19 ± 14;à30 min:-Mo 3 ± 4/Mc 5 ± 4). Les groupes ropivacaïne et bupivacaïne ont présenté un plus long délai d’installation (à 10 min: — Ro 23 ± 19 / Rc 25 ± 22 /Bo 24 ± 15; à 30 min: — Ro 10 ± 6/Rc 11 ± 6/ Bo 12 ± 4). Le délai d’installation s’est prolongé de façon significative dans le groupe — Bc (à 10 min: — 45 ± 21; à 30 min: — 20 ± 6). La durée du blocage moteur a été prolongée par la clonidine dans les groupes mépivacaïne et bupivacaïne seulement; (en minutes: Mo 212 ± 47 – Mc 468 ± 62; Ro 702 ± 52 – Rc 712 ± 82; Bo 728 ± 36-Bc 972 ± 72).ConclusionLa présente étude montre que l’addition de clonidine provoque des effets différents sur chacun des trois anesthésiques locaux expérimentés quant au délai d’installation et à la durée de l’anesthésie.

Tracheal intubation and cervical spine excursion: direct laryngoscopy vs. intubating laryngeal mask

Until recently, the most appropriate technique of intubating a patient with a cervical spine injury has been the subject of debate. Tracheal intubation by means of the intubating laryngeal mask (Fastrach™), a modified conventional laryngeal mask airway, seems to require less neck manipulation. The aim of this study was to compare the excursion of the upper cervical spine during tracheal intubation using direct laryngoscopy with that during intubation via the laryngeal mask (Fastrach™), by examination of lateral cervical spine radiographs in healthy young patients. The intubating laryngeal mask (Fastrach™) caused less extension (at C1−2 and C2−3) than intubation by direct laryngoscopy. Direct laryngoscopy is still the fastest method to secure an airway provided no intubating difficulties are present. However, in trauma patients requiring rapid sequence induction and in whom cervical spine movement is limited or undesirable, the intubating laryngeal mask (Fastrach™) is a safe and fast method by which to secure the airway.

Ultrasonographic guided axillary plexus blocks with low volumes of local anaesthetics: a crossover volunteer study

Our study group recently evaluated an ED95 local anaesthetic volume of 0.11 ml.mm−2 cross‐sectional nerve area for the ulnar nerve. This prospective, randomised, double‐blind crossover study investigated whether this volume is sufficient for brachial plexus blocks at the axillary level. Ten volunteers received an ultrasonographic guided axillary brachial plexus block either with 0.11 (‘low’ volume) or 0.4 (‘high’ volume) ml.mm−2 cross‐sectional nerve area with mepivacaine 1%. The mean (SD) volume was in the low volume group 4.0 (1.0) and 14.8 (3.8) ml in the high volume group. The success rate for the individual nerve blocks was 27 out of 30 in the low volume group (90%) and 30 out of 30 in the high volume group (100%), resulting in 8 out of 10 (80%) vs 10 out of 10 (100%) complete blocks in the low vs the high volume groups, respectively (NS). The mean (SD) sensory onset time was 25.0 (14.8) min in the low volume group and 15.8 (6.8) min in the high volume group (p < 0.01). The mean (SD) duration of sensory block was 125 (38) min in the low volume group and 152 (70) min in the high volume group (NS). This study confirms our previous published ED95 volume for mepivacaine 1% to block peripheral nerves. The volume of local anaesthetic has some influence on the sensory onset time.

The effects of clonidine on ropivacaine 0.75% in axillary perivascular brachial plexus block.

The new long‐acting local anesthetic ropivacaine is a chemical congener of bupivacaine and mepivacaine. The admixture of clonidine to local anesthetics in peripheral nerve block has been reported to result in a prolonged block. The aim of the present study was to evaluate the effects of clonidine added to ropivacaine on onset, duration and quality of brachial plexus block.

Intubating laryngeal mask and rapid sequence induction in patients with cervical spine injury

The Intubating Laryngeal Mask (FastrachTM), a modified conventional laryngeal mask airway, and its prototype cuffed silicone tube, continue to be an appropriate intubating tool in combination with fibreoptic bronchoscopy in the emergency situation. This is an account of two patients with suspected cervical spine fracture admitted to our emergency room in a haemodynamically unstable condition and requiring a rapid sequence induction of anaesthesia, in whom we successfully applied this newly developed intubating device for the first time. Provided that there are no intubation difficulties, direct laryngoscopy is still the fastest method of securing an airway; however, this procedure leads to an extension of the cervical spine, which may be hazardous in the case of a cervical spine injury. Intubation by means of the Intubating Laryngeal Mask avoids dangerous hyperextension of the occipito‐atlanto‐axial complex, a fact that we were able to verify by lateral cervical spine fluoroscopy during intubation.

Ultraschall in der Regionalanästhesie

ZusammenfassungIn der Regionalanästhesie stellt die Lokalisation der zu blockierenden Nerven eine besondere Herausforderung dar. Seit der Zeit der ersten Regionalanästhesieverfahren vor ca. 100 Jahren ist die wesentliche Einschränkung dieser Methodik in den nicht befriedigenden Erfolgsraten und den spezifischen Risiken zu sehen. Auch durch Variation des Zugangsweges zu den verschiedenen Nerven oder durch verschiedene Identifikationsmethoden konnte keine ideale Blockadetechnik erarbeitet werden, die gleichzeitig eine Erfolgsquote von 100% ermöglicht und die Risiken minimiert. Die klinische Einführung verschiedener Hilfsmittel, wie die Nervenstimulation oder die Dopplersonographie, erbrachte trotz unumstrittener Verbesserungen bisher keine statistisch signifikanten Vorteile. In den letzten Jahren zeigte sich in der perioperativen Versorgung aufgrund der nachzuweisenden Vorteile und Möglichkeiten ein deutlicher Trend in Richtung Regionalanästhesie. Mehrere Arbeitsgruppen entwickelten Methoden zur sonographischen Identifikation von Nerven oder des Epiduralraumes und zur sicheren Platzierung von Nadeln oder Kathetern unter Berücksichtigung der gewonnenen Informationen. Die Applikation von Kathetern und die Injektion des Lokalanästhetikums kann auf diese Weise gezielt und kontrolliert durchgeführt werden. Obwohl die Sonographie im Rahmen der Regionalanästhesie ein Verfahren ist, das bereits 10 Jahre alt ist, gibt es bis zum heutigen Tag nur wenige regionalanästhesiologisch tätige Anästhesisten, die dieses Verfahren einsetzen können. Allerdings steigt das Interesse an dieser Methodik deutlich an, insbesondere aus Gründen der Qualitätssicherung. Zentrale Gremien haben festgestellt, dass diese Methodik zukunftsweisend sein wird. Vielleicht wird sich sogar die Aussage von Alon P. Winnie für die ultraschallgestützte Regionalanästhesie bewahrheiten: “Sooner or later someone will make a sufficiently close examination of the anatomy involved, so that exact techniques will be developed.”AbstractThe localisation of the nerve to be blocked is one of the special challenges in local anaesthesia. Since the first time local anaesthesia procedures were carried out approximately 100 years ago, the basic limitations of this method have always been the unsatisfactory success rate and the specific risks involved. Even by variation of the access route to the various nerves and use of different identification methods, no ideal blockade technique has been found which allows a 100% success rate and at the same time reduces the risks to a minimum. The clinical introduction of various aids, such as nerve stimulation or Doppler sonography, have brought no statistically significant advantages despite showing clear improvements. In recent years there has been a trend towards local anaesthesia in perioperative care due to the proven advantages and range of possibilities. Several working groups have developed methods for the sonographic identification of nerves or the epidural space and to an exact placing of needles or catheters from the information obtained. In this way the application of catheters and the injection of local anaesthetic agents can be carried out in an accurate and controlled manner. Although sonography is a procedure which has been used in local anaesthesia for over 10 years, there are at present only few practising local anaesthetists who can use this method. However, interest in this method is growing especially due to the aspect of quality assurance. Organising committees have established that this method will be the future direction. Perhaps even the prediction of Alon P. Winnie for ultrasound-guided local anaesthesia will become true: “Sooner or later someone will make a sufficiently close examination of the anatomy involved, so that exact techniques will be developed.”