[Hyperbaric subarachnoid ropivacaine in ambulatory surgery: comparative study with hyperbaric bupivacaine]. / Ropivacaína hiperbárica subaracnoidea en cirugía ambulatoria: estudio comparativo con bupivacaína hiperbárica.

OBJECTIVES: To compare the clinical efficacy of hyperbaric 0.5% ropivacaine and 0.5% bupivacaine in subarachnoid blockade for ambulatory surgery. MATERIAL AND METHOD: Randomized double-blind study of 90 patients undergoing lower abdominal surgery. Subarachnoid blockade was achieved with 0.5% ropivacaine (12.5 mg) or 0.5% bupivacaine (12.5 mg) in 10% glucose. We recorded age, sex, weight, latency, extension of motor and sensory blocks, duration of surgery, side effects and quality as perceived by the surgeon and the patient. RESULTS: The two groups were similar with respect to latency time and extension of sensory block. Durations of motor (68.9 +/- 22.9 min) and sensory (127.0 +/- 24.3 min) blocks were significantly shorter with ropivacaine than with bupivacaine (133.3 +/- 29.4 and 174.9 +/- 25.5 min, respectively). Patients in the ropivacaine group also experienced a less intense motor block (Bromage 1, 11.1% vs. 93.3%) and fewer episodes of hypotension 0% vs. 17.7%) or bradycardia (4.4% vs. 8.8%) than those in the bupivacaine group. No neurotoxic effects or instances of postdural puncture headache were recorded. CONCLUSIONS: Hyperbaric 0.5% ropivacaine offers certain advantages over hyperbaric 0.5% bupivacaine for subarachnoid block in outpatient surgery. Duration and intensity of the sensory-motor blockade is less with ropivacaine and fewer cardiovascular side effects develop.

[Cauda equina hemisyndrome after intradural anesthesia with bupivacaine for hip surgery]. / Hemisíndrome de cauda equina tras anestesia intradural con bupivacaína para cirugía de la cadera.

A 68-year-old man underwent hip surgery under subarachnoid anesthesia with bupivacaine and fentanyl to replace an acetabular component. Two days after surgery the patient developed unilateral cauda equina syndrome, affecting five nerve roots (L4 to S3), with no sphincter involvement. Two and a half years later, the lesion had become permanent. We discuss the possible origin of the condition, suggesting differential diagnoses such as mechanical problems (position-mobilization) and anesthetic toxicity.

[Lack of predictive power of cerebrospinal fluid calcitonin and serotonin concentrations for the intensity of postoperative pain and the duration of analgesia after subarachnoid morphine administration]. / Ausencia de poder predictivo de las concentraciones de calcitonina y serotonina en líquido cefalorraquídeo sobre la intensidad del dolor posquirúrgico y la duración de la analgesia tras la administración subaracnoidea de morfina.

Based on the important relationship of calcitonin and serotonin with narcotic drugs at the level of the central nervous system and with the modulating mechanisms of pain sensation, we have studied whether central baseline levels of these modulators possess a predictive value for the assessment of the intensity and duration of narcotic spinal analgesia. Therefore, intradural levels of calcitonin an serotonin were measured in 18 patients who underwent and infraumbilical laparotomy with intradural anesthesia with bupivacaine associated with 0.5 mg of morphine. There was no statistically significant correlation between the levels of calcitonin and serotonin with the age, weight, height, sex, values of analogic visual scale 2, 4, 6, 12 and 24 hours after lumbar punction, and duration of the analgesia. Even though a correlation exists in experimental models, our results indicate that baseline values of modulators calcitonin and serotonin lack of predictive value for the assessment of the degree and duration of narcotic spinal analgesia.