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

PURPOSE: To 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. METHODS: One hundred and twenty trauma-patients were randomly allocated into six groups. In the control-groups (Mo/Ro/Bo) brachial plexus was performed using 40 mL of local anesthetic plus 1 mL of NaCL 0.9%. In the clonidine-groups (Mc/Rc/Bc) brachial plexus was performed using each 40 mL of drug plus 1 mL (0.150 mg) of clonidine. Onset-time and the duration of the sensory block were recorded. Data are expressed as mean +/- SD. RESULTS: According 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 +/- 19/Rc 25 +/- 22/Bo 24 +/- 15; at 30 min -Ro 10 +/- 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). CONCLUSION: The 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.

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.

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.