Regional anesthesia
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Regional anesthesia · Mar 1989
Comparative StudyA comparison of cardiovascular responses of normotensive and hypertensive elderly patients following bupivacaine spinal anesthesia.
The hypotensive effects of spinal anesthesia were investigated in 60 patients aged 75 years or older and divided into two groups: 30 normotensive patients (group 1) and 30 treated hypertensive patients (group 2). In both groups, spinal anesthesia was performed in lateral decubitus position with 3 ml 0.5% isobaric bupivacaine. Hemodynamic measurements were performed before the establishment of spinal blockade and repeated during the 60 minutes following intrathecal injection. ⋯ Five patients in group 2 (but none in group 1) had a SBP decrease of 40% from baseline or more. The decreases in MBP and DBP were persistent after 60 minutes. These results suggest that pre-existing hypertension can be recognized as an important factor to explain blood pressures changes during isobaric bupivacaine spinal anesthesia in elderly patients.
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Regional anesthesia · Mar 1989
Contractility effects of local anesthetics in the presence of sodium channel blockade.
The effects of lidocaine (25, 50 and 100 micrograms/ml) and bupivacaine (5, 10, and 20 micrograms/ml) on amplitude, velocity, and contraction frequency were studied in monolayer cultures of spontaneously beating chick embryo ventricular cells. The physiologic parameters of contraction frequency, amplitude, and velocity of shortening were measured with an optical-video system. Studies were also carried out in the presence of 1 microM tetrodotoxin (TTX) to isolate effects caused by TTX-sensitive ion channel blockade from other possible mechanisms of action of local anesthetics. ⋯ In the presence of TTX, lidocaine (50 micrograms/ml) produced a further decrease in amplitude of contraction, but no significant change in contraction frequency or velocity of contraction. It is well known that local anesthetics block Na+ channels of excitable membranes. The authors observations suggest that both lidocaine and bupivacaine have at least one locus of action at a site other than a TTX blockade site.
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Regional anesthesia · Mar 1989
A two-person technique for epidural needle placement and medication infusion.
Traditional techniques of epidural needle placement have not proved satisfactory in patients who have had a previous laminectomy and may have epiduroarachnoiditis. A two-person technique was developed to: 1) simplify performance of difficult, epidural needle placement; 2) allow both resident and staff a simultaneous "hands-on" teaching experience; 3) allow a painless method of medication administration in patients with altered epidural anatomy; and 4) allow a simple method for determination of epidural space pressures. A glass syringe and extension tubing filled with saline are connected to the epidural needle. ⋯ The column of saline falls and fluctuates with heart beat, providing verification of correct needle placement. Medication is placed in the barrel of the syringe and allowed to infuse by gravity. The two-person technique has achieved both patient and resident acceptance, and allows a painless method of medication administration in patients with altered epidural space anatomy.
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Four local or regional anesthesia techniques for the insertion of cardiac pacemaker were studied prospectively in 40 patients. The four techniques studied were: local anesthesia, field block of the supraclavicular nerves, interscalene block at C4, and interscalene block at C6. The three goals of the study were to find the technique that gave the best quality of analgesia, the incidence of complications related to each technique, and the area of sensory innervation of C4. ⋯ Interscalene blocks at C4 and C6 were associated with complications and side effects more often than the two other techniques. The authors also suggest that the dermatome of C4 is not under the clavicle but above the clavicle. It was concluded that local anesthesia infiltration at the site of cardiac pacemaker insertion or field block of the supraclavicular nerves are the best techniques for cardiac pacemaker insertion.
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Regional anesthesia · Mar 1989
A retrospective analysis of neurolytic celiac plexus block for nonpancreatic intra-abdominal cancer pain.
Neurolytic celiac plexus block (NCPB) has been reported to be an effective method for pain relief for a variety of intra-abdominal malignancies, especially pancreatic. In spite of this, few data exist concerning efficacy of the block for pain related to other intraabdominal tumors. ⋯ The incidence of neurologic injury (footdrop) was less than 0.5%. This therapy deserves more widespread use in patients with abdominal pain secondary to a variety of other malignancies, in addition to that of the pancreas.