[Patient satisfaction with spinal cord stimulation for failed back surgery syndrome]. / Satisfacción del paciente con síndrome de dolor de raquis postquirúrgico portador de un sistema de neuroestimulación medular.

INTRODUCTION: The incidence of failed back surgery syndrome is about 40%. We studied the efficacy of and patient satisfaction with use of a spinal cord stimulator to treat this syndrome. MATERIAL AND METHODS: A period of 72 months of experience with implanted spinal cord stimulators was analyzed in this observational, descriptive study of patients who were included retrospectively. Patients met criteria for failed back surgery syndrome according to the taxonomy of the International Association for the Study of Pain. A chi2 test was used to compare qualitative variables. Results for quantitative variables were compared by analysis of variance. Statistical significance was set at P < 0.05. RESULTS: Thirty-four patients were studied. Both lumbar back and radicular pain assessed on a visual analog scale (VAS) decreased significantly from the mean overall score of 6. As time passed, fewer patients felt the system met their expectations. More patients said the system met their expectations in the first months after implantation (73.5%) than at a later interview (55.9%). Seventeen complications were reported, the most common being mechanical difficulties with the implanted stimulator. None of the complications were serious. Use of additional medication to control pain decreased in 38.2% of the cases. A total of 73.5% of the patients considered the implanted stimulator to be beneficial and 67.6% would have a spinal cord stimulator implanted again. CONCLUSIONS: Spinal cord stimulation improves lumbar back pain in patients with failed back surgery syndrome and reduces the amount of additional medication taken to control pain. It is important for patients to adjust their expectations about the implanted stimulator.

[Ketamine for subarachnoid anesthesia during hypovolemia: preliminary study in pigs]. / Utilización de ketamina para anestesia subaracnoidea durante hipovolemia. Estudio experimental preliminar en cerdos.

OBJECTIVES: To assess whether subarachnoid ketamine has fewer hemodynamic effects than lidocaine in normal and hypovolemic pigs and to determine whether or not the effects of ketamine are dose-dependent. METHODS: Thirty pigs were randomly allocated to receive subarachnoid administration of lidocaine 2 mg x kg(-1), ketamine 1 mg x kg(-1) or ketamine 2 mg x kg(-1), in a situation of either normal or reduced blood volume. The pigs were assigned to six groups: group L2 (2% lidocaine 2 mg x kg(-1), normovolemia), group L2H (2% lidocaine 2 mg x kg(-1), hypovolemia), group K1 (ketamine 1 mg x kg(-1), normovolemia), group K1H (ketamine 1 mg x kg(-1), hypovolemia), group K2 (ketamine 2 mg.kg(-', normovolemia), and group K2H (ketamine 2 mg x kg(-1), hypovolemia). To induce hypovolemia 30% of the calculated blood volume was withdrawn from each pig. The subarachnoid space was catheterized, and invasive measurements of hemodynamic variables (derived from arterial, central venous and pulmonary artery catheter monitoring) were obtained. Variables were recorded at baseline and 5 and 15 min after drug injection in the normovolemic groups, and at baseline after inducing hypovolemia and 5 and 15 min after drug injection in the hypovolemic groups. RESULTS: In the normovolemic pigs no significant differences were detected between groups. In hypovolemic pigs differences were observed in heart rate and arterial pressure between the ketamine 1 mg x kg(-1) and lidocaine 2 mg x kg(-1) groups (P < 0.05). The decreases in heart rate and arterial pressure were less marked in the ketamine group. Mixed venous oxygen saturation and cardiac index deteriorated to a lesser degree in both ketamine groups than in the lidocaine groups (P < 0.05). CONCLUSIONS: Racemic ketamine administered by subarachnoid injection in hypovolemic pigs produces less deterioration in hemodynamic variables than does lidocaine. Hemodynamic changes caused by ketamine were not dose-dependent. These findings may be of interest, given the increased use of ketamine in neuroaxial anesthesia and analgesia and perhaps the possible use of neuroaxial ketamine in hypovolemic patients.

[Epidural anesthesia and analgesia in the perioperative treatment of a patient with Kartagener syndrome]. / Anestesia y analgesia epidurales en el tratamiento perioperatorio de una paciente con síndrome de Kartagener.

Kartagener's syndrome is an inherited disease characterized by a triad of symptoms--bronchiectasis, situs inversus and sinusitis--and is classified as an immotile cilia syndrome. Patients may experience specific airway problems when undergoing anesthesia for surgical procedures. We report the case of a woman with Kartagener's syndrome who underwent surgery under epidural anesthesia with postoperative epidural analgesia, both techniques proving successful.