Anesthesia and analgesia
-
Anesthesia and analgesia · May 2009
ReviewModern rapidly degradable hydroxyethyl starches: current concepts.
Hydroxyethyl starch (HES) is a widely used plasma substitute for correcting perioperative hypovolemia. HES preparations are defined by concentration, molar substitution (MS), mean molecular weight (M(w)), the C(2)/C(6) ratio of substitution, the solvent, and the origin. The possible unwanted side effects of HES are anaphylactic reactions, alterations of hemostasis resulting in increased bleeding, kidney dysfunction, accumulation, and pruritus. ⋯ This review is focused on whether modern (third generation), more rapidly degradable HES preparations with a lower M(w) (130 kD) and a lower MS (<0.5) are safer and have fewer side effects. Several studies demonstrated that such modern HES preparations appear to be safe with regard to hemostasis, kidney function, itching, and accumulation. Modern HES preparations are dissolved in balanced, plasma-adapted solutions that no longer contain unphysiological amounts of sodium and chloride and are thus suitable for correcting hypovolemia.
-
Anesthesia and analgesia · May 2009
Randomized Controlled TrialColloid preload versus coload for spinal anesthesia for cesarean delivery: the effects on maternal cardiac output.
Spinal anesthesia for cesarean delivery may cause severe maternal hypotension, and a decrease in cardiac output (CO) and blood flow to the placenta. Fluid preloading with crystalloid is ineffective due to rapid redistribution. A "coload" given at the time of cerebrospinal fluid identification may be more effective. Our null hypothesis was that there would be no difference between the effect of a colloid preload (15 mL/kg hydroxyethyl starch (HES) 130/0.4 [Voluven 6%]) and an identical coload on maternal CO and the incidence of hypotension after spinal anesthesia for cesarean delivery. Secondary outcomes studied were neonatal acid- base status and predelivery vasopressor requirements. ⋯ Intravascular volume expansion with 15 mL/kg HES 130/0.4 given as a preload, but not coload, significantly increased maternal CO for the first 5 min after spinal anesthesia for cesarean delivery, however, maternal and neonatal outcomes were not different.
-
Anesthesia and analgesia · May 2009
Fluoroscopically guided cervical interlaminar epidural injections using the midline approach: an analysis of epidurography contrast patterns.
The purpose of this study was to evaluate epidurography contrast patterns in fluoroscopically guided cervical interlaminar epidural injections using the midline approach. ⋯ Two milliliters of contrast solution can provide optimal dispersion of contrast in a ventral and longitudinal spread.
-
Anesthesia and analgesia · May 2009
Propofol produces immobility via action in the ventral horn of the spinal cord by a GABAergic mechanism.
We investigated the actions of propofol and isoflurane on nociceptive responses of neurons in the spinal cord. ⋯ Propofol acts in the spinal cord to produce immobility. This depressive effect occurs in the ventral horn and is mediated mainly by GABA(A) receptors. Isoflurane also depresses neurons in the ventral horn; however, isoflurane actions at the GABA(A) receptor are either weak or overridden by other effects in the ventral horn.
-
Anesthesia and analgesia · May 2009
The effect of amitriptyline on ectopic discharge of primary afferent fibers in the L5 dorsal root in a rat model of neuropathic pain.
The sodium channel blocker amitriptyline has been shown to inhibit ectopic discharge in injured nerves. In the present study, we characterized ectopic discharges of afferent fibers following L5/L6 spinal nerve ligation (SNL) by their electrophysiological properties and sensitivities to inhibition by amitriptyline in the decentralized L5 dorsal root in SNL rats. ⋯ These results provide direct evidence that amitriptyline, which is used clinically for the treatment of neuropathic pain, selectively inhibits ectopic discharge of low frequency and bursting discharge in the rat neuropathic pain model.