[Neurologic complications of central neuraxial blocks]. / Complicaciones neurológicas en los bloqueos centrales.

Central neuraxial blocks, which are associated with a low incidence of complications, are safe. When complications do occur, however, the resulting morbidity and mortality is considerable. The reported incidence of complications in all series is under 4 per 10000 patients, but given the absence of formal registries and notification procedures, which have legal implications, the real rate of occurrence of these rare events is uncertain. We searched the literature through PubMed and the Cochrane Plus Library for a 5-year period, using the search terms epidural anesthesia AND safety, spinal anesthesia AND safety, complications AND epidural anesthesia, complications AND spinal anesthesia, neurologic complications AND epidural anesthesia, and neurologic complications AND spinal anesthesia. Neuraxial injury after a central blockade may be the result of anatomical and/or physiological lesions affecting the spinal cord, spinal nerves, nerve roots, or blood supply. The pathophysiology of neuraxial injury may be related to mechanical, ischemic, or neurotoxic damage or any combination. When a complication occurs, factors related to the technique will have interacted with pre-existing patient-related conditions. Various scientific societies have published guidelines for managing the complications of regional anesthesia. Recently published clinical practice guidelines recommend ultrasound imaging as a useful tool in performing a central neuraxial block.

The usefulness of interpectoral block as an analgesic technique in breast cancer surgery. / Utilidad del bloqueo interpectoral continuo como técnica analgésica en cirugía oncológica de mama.

OBJECTIVE: To compare the analgesic efficacy of continuous interpectoral block (CIPB) compared to intravenous analgesia (IV) after breast surgery. MATERIAL AND METHOD: A prospective, comparative and randomised study of women aged from 18-75years, ASAI-III, operated for breast cancer. In group1 (CIPB) after general anaesthetic, an ultrasound-guided interpectoral catheter was placed and 30mL of 0.5% ropivacaine was administered through it. In the event of an increase in heart rate and blood pressure >15% after the surgical incision, intravenous fentanyl 1µg·kg-1 was administered, repeating the dose as necessary. In the postoperative period, perfusion of ropivacaine 0.2% 5mL·h-1; with PCA bolus 5mL/30minutes was administered through the catheter for 24hours and rescue analgesia prescribed with 5mg subcutaneous morphine chloride. In group2 (IV), after induction of general anaesthesia, intravenous fentanyl was administered in the same way as in the other group. The patients received metamizole 2g with dexketoprofen 50mg and ondansetron 4mg postoperatively followed by perfusion of metamizole 4%, tramadol 0.2% and ondansetron 0.08% 2ml·h-1; with PCA bolus 2mL/20min for 24hours. The same rescue analgesia was prescribed. The principal variables recorded were pain at rest and during movement, according to a simple verbal scale (VAS 0-10) and the rescue analgesia required on discharge from recovery, at 12 and at 24hours. RESULTS: 137 patients were included: 81 in group1 (59.12%) and 56 in group2 (40.87%). No significant differences were observed in the analgesia between either group, but differences were observed in the dose of intraoperative fentanyl (P<.05). Differences that were not significant were observed in the rescue analgesia required on recovery (10% fewer on group1). CONCLUSIONS: Both techniques provided effective postoperative analgesia, but the CIPB group required significantly less intraoperative fentanyl.

[Influence of femoral catheter stimulation intensity on post-surgical analgesia after total knee replacement]. / Influencia de la intensidad de estimulación del catéter femoral sobre analgesia postoperatoria tras prótesis de rodilla.

INTRODUCTION: Stimulating catheters allow the catheter point to be positioned near the nerve, thus reducing the amount of local anaesthetic required for a successful block. There is currently a debate on what is the stimulation intensity required to provide adequate analgesia, although it does seem that if it is obtained with 1mAmp or less the block is more effective. The objective of the study was to demonstrate whether different neurostimulation intensities with the stimulating catheter at femoral nerve level, had an influence on the adequacy of post-surgical analgesia during the 48h after total knee arthroplasty. MATERIAL AND METHODS: A comparative, prospective and randomised study was conducted on patients subjected to total knee replacement. After surgery with subarachnoid anaesthesia, a continuous femoral block was performed with a stimulating catheter at a neurostimulation intensity 0.2 and 0.5mAmp in Group 1, between 0.6 and 1mAmp in Group 2, equal or higher than 1.1mAmp in Group 3, and in Group 4 the catheter was introduced between 3-5cm without looking for a motor response. A dose of 0.2% ropivacaine 0.4mL/kg and an infusion at 5mL/h, with boluses of 10mL/30min, was administered via the catheter. Sciatic nerve block was also performed on all patients with 20ml of 0.5% ropivacaine. The patient demographics were recorded, as well as, post-surgical analgesia details, sensory and motor block in each area, boluses requested, rescue analgesia, and undesirable effects at 8, 16, 24, 36 and 48h. RESULTS: A total of 124 patients were included, 32 in Group 1 (25.8%), 21 in Group 2 (16.9%), 31 in Group 3 (25%), and 40 in group 4 (32.3%). The 4 groups were homogeneous as regards age, height, weight and ASA. There were no statistically significant differences found in the post-operative pain, except during movement in the femoral area at 36 hours (p=.032). There were also no statistically significant differences found in the sensory block in the femoral area at 48 hours (p=.019) and in the femoral cutaneous nerve block at 8 hours (p=.049) or at 24 hours (p=.045). As regards motor block, differences were only found in the obturator nerve at 24 hours (p=.016). There were no differences in rescue analgesia, patient controlled analgesia (PCA) boluses requested or administered, except that the number of boluses requested at 16 hours was less in Group 3 (p=.049). There were also no significant differences in undesirable effects or in the level of satisfaction of the patients between the four groups. CONCLUSIONS: In our study, no influence was found on the level of analgesia provided after knee replacement surgery with the neurostimulation intensity to which the neuromuscular system involved responded when a stimulating catheter is inserted at femoral level.