Metabolic forearm vasodilation is enhanced following Bier block with phentolamine.
(49/148)
The extent to which sympathetic nerve activity restrains metabolic vasodilation in skeletal muscle remains unclear. We determined forearm blood flow (FBF; ultrasound/Doppler) and vascular conductance (FVC) responses to 10 min of ischemia [reactive hyperemic blood flow (RHBF)] and 10 min of systemic hypoxia (inspired O(2) fraction = 0.1) before and after regional sympathetic blockade with the alpha-receptor antagonist phentolamine via Bier block in healthy humans. In a control group, we performed sham Bier block with saline. Consistent with alpha- receptor inhibition, post-phentolamine, basal FVC (FBF/mean arterial pressure) increased (pre vs. post: 0.42 +/- 0.05 vs. 1.03 +/- 0.21 units; P < 0.01; n = 12) but did not change in the saline controls (pre vs. post: 0.56 +/- 0.14 vs. 0.53 +/- 0.08 units; P = not significant; n = 5). Post-phentolamine, total RHBF (over 3 min) increased substantially (pre vs. post: 628 +/- 75 vs. 826 +/- 92 ml/min; P < 0.01) but did not change in the controls (pre vs. post: 618 +/- 66 vs. 661 +/- 35 ml/min; P = not significant). In all conditions, compared with peak RHBF, peak skin reactive hyperemia was markedly delayed. Furthermore, post-phentolamine (pre vs. post: 0.43 +/- 0.06 vs. 1.16 +/- 0.17 units; P < 0.01; n = 8) but not post-saline (pre vs. post: 0.93 +/- 0.16 vs. 0.87 +/- 0.19 ml/min; P = not significant; n = 5), the FVC response to hypoxia (arterial O(2) saturation = 77 +/- 1%) was markedly enhanced. These data suggest that sympathetic vasoconstrictor nerve activity markedly restrains skeletal muscle vasodilation induced by local (forearm ischemia) and systemic (hypoxia) vasodilator stimuli. (+info)
Transsacrococcygeal approach to ganglion impar block for management of chronic perineal pain: a prospective observational study.
(50/148)
BACKGROUND: The ganglion impar or ganglion of Walther is a solitary retroperitoneal structure at the level of sacrococcygeal junction. It provides the nociceptive and sympathetic supply to the perineal structures. Chronic Perineal Pain (CPP) has been effectively managed by ganglion impar block. In this study we analyze the feasibility, safety, and efficacy of ganglion impar block by transsacrococcygeal approach. DESIGN: An observational report. METHODS: In this prospective study, 16 consecutive patients who required ganglion impar block for CPP were followed for two months. After informed and written consent, the ganglion impar was blocked under aseptic precautions, using a transsacrococcygeal approach. The Visual Analogue Scale for pain (VAS) at presentation time required for the pain to reduce by 50% to be considered effective and VAS was recorded at different time points during 2-month follow-up, and time required to perform the procedure, number of attempts, and any complications were also noted. RESULTS: All the blocks were effective with a mean duration of 12+/-3 minutes for 50% reduction in VAS. The mean duration required to perform the procedure in neurolytic block patients was 7.8+/-2 minutes and 5.7+/-1 minutes in therapeutic block patients. There were no adverse events. All the patients had significant pain relief during 2 month follow-up (p <0.05 compared to baseline). The mean VAS at 2 months was about 2. Statistical analysis was done by using paired "t"/Wilcoxon signed rank test. CONCLUSION: A transsacrococcygeal approach for a ganglion impar block is a technically feasible and safe technique. We recommend this technique for neurolysis or radiofrequency ablation of the ganglion impar and for diagnostic blocks, especially when the diagnosis and further plan of management is dependent on the response of the diagnostic block. (+info)
Stellate ganglion block is utilized in the diagnosis and management of various vascular disorders and sympathetically mediated pain in the upper extremity, head and neck. The cervical sympathetic chain is composed of superior, middle, intermediate, and inferior cervical ganglia. However, in approximately 80% of the population, the inferior cervical ganglion is fused with the first thoracic ganglion, forming the stellate ganglion also known as cervicothoracic ganglion. The stellate ganglion lies medial to the scalene muscles, lateral to the longus coli muscle, esophagus and trachea along with the recurrent laryngeal nerve, anterior to the transverse processes and prevertebral fascia, superior to the subclavian artery and the posterior aspect of the plura, and posterior to the vertebral vessels at C7 level. Consequently, inadvertent placement of the needle into the vertebral artery, thyroid, neural tissues, or esophagus can occur with the fluoroscopic or blind approach. While fluoroscopy is a reliable method for identifying boney structures, ultrasound may identify the vertebral vessels, thyroid gland and vessels, longus coli muscles, nerve roots and the esophagus. Thus, ultrasound may prevent inadvertent placement of the needle into these structures as might happen with either the blind technique or fluoroscopic technique. A patient with complex regional pain syndrome type I of the left upper extremity was scheduled for left stellate ganglion block with the anterior paratracheal approach under fluoroscopy. Real-time ultrasound imaging prevented inadvertent injury to the esophagus as well as the thyroid gland and vessels. Ultrasound-guided block may improve patient safety by avoiding the soft tissue structures in the needle path that can't be readily seen by fluoroscopy. This may be particularly useful in the patient with asymptomatic pharyngoesophageal diverticulum (Zenker diverticulum). (+info)
Inferior hypogastric plexus blockade: a transsacral approach.
(52/148)
BACKGROUND: Despite recent refinements in the technique of hypogastric plexus blockade, the lower pelvic organs and genitalia are innervated by fibers from the pre-sacral inferior hypogastric plexus and these fibers are not readily blocked using paravertebral or transdiscal approaches. DESIGN: Report of a technique to introduce a transsacral approach to blockade of the inferior hypogastric plexus. METHODS: A technique for performing inferior hypogastric plexus blockade by passing a spinal needle through the sacral foramen is described with 15 blocks in 11 patients. RESULTS: Fifteen inferior hypogastric plexus blocks were performed on 11 female patients who presented with chronic pelvic pain. Pelvic pain was decreased following 11 of the procedures with pre- and post-pain scores (SD) of 7.4 (2.3) and 5.0 (2.7), respectively (P < 0.05). There were no complications or unusual occurrences. CONCLUSIONS: This block can be performed safely and effectively if the interventionalist has a high degree of familiarity with sacral anatomy, refined needle steering technique, and expertise in fluoroscopy. Properly performed, transsacral blockade of the inferior hypogastric plexus is a safe technique for the diagnosis and treatment of chronic pain conditions involving the lower pelvic viscera. (+info)
Investigating feedforward neural regulation of circulation from analysis of spontaneous arterial pressure and heart rate fluctuations in conscious rats.
(53/148)
Thoracic epidural analgesia with low concentration of bupivacaine induces thoracic and lumbar sympathetic block: a randomized, double-blind clinical trial.
(54/148)
Postoperative fall after the use of the 3-in-1 femoral nerve block for knee surgery: a report of four cases.
(55/148)
We present a serious postoperative complication related to the use of femoral nerve block in 4 patients, each of whom fell and sustained further injury. Preoperatively, all patients underwent a 3-in-1 femoral nerve block with 30 to 35 ml of 0.25% levobupivacaine with 1:200,000 epinephrine, with guidance by a nerve stimulator. After the falls, neurological examination of the operated legs revealed reduced 2-point discrimination, pain, and/or light touch sensation. All patients underwent further operation for the fall injury and had delayed full weight bearing. We recommend that, after having a femoral nerve block, patients should undergo enhanced postoperative evaluation of blockade and proprioceptive function to ensure safe neurological function before mobilisation. (+info)
Phenol neurolysis for relieving intermittent involuntary painful spasm in upper motor neuron syndromes: a pilot study.
(56/148)