Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2003
The effects of pyrilamine and cimetidine on mRNA C-fos expression and nociceptive flinching behavior in rats.
C-fos and Fos expression, frequently used as a neural nociceptive marker, is altered by many drugs. The effects of histamine receptor antagonists on c-fos messenger (m)RNA expression are unknown. We examined the effect of local and systemic administration of pyrilamine (H(1) receptor antagonist) and cimetidine (H(2) receptor antagonist) on the nociceptive flinching behavior elicited by injection of 50 micro L of 1% formalin into the dorsal region of the hind paw of rats. Nociceptive flinching behavior was observed for 45 min, and the rats were then killed and lumbar spinal cord obtained for c-fos mRNA expression, measured using the Northern blot hybridization technique. Systemic administration of pyrilamine and cimetidine did not elicit response in nociceptive behavior or in c-fos mRNA expression. When the drugs were locally administered, they affected behavior and c-fos mRNA expression in different patterns. Pyrilamine decreased the number of flinches in a dose dependent manner in both phases, whereas cimetidine did not affect Phase I and decreased the number of flinches in Phase II, but only partially. Pyrilamine 5 and 20 mM decreased c-fos mRNA expression, and cimetidine decreased the expression only at 100 mM. The systemic use of the drugs had no effect on c-fos mRNA expression. ⋯ Histamine receptor antagonists present antinociceptive effects when administered peripherally. These effects are observed through a nociceptive flinching behavior test and mRNA c-fos expression. Pyrilamine (H(1) receptor antagonist) has a greater antinociceptive effect than cimetidine (H(2) receptor antagonist).
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Anesthesia and analgesia · Aug 2003
The bispectral index declines during neuromuscular block in fully awake persons.
Using an Aspect A-1000 BIS monitor, researchers demonstrated a drop in Bispectral Index Score in awake, paralysed volunteers to low values ranging from 9 to 64.
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Anesthesia and analgesia · Aug 2003
Randomized Controlled Trial Multicenter Study Clinical TrialDiaspirin-crosslinked hemoglobin reduces blood transfusion in noncardiac surgery: a multicenter, randomized, controlled, double-blinded trial.
In this randomized, prospective, double-blinded clinical trial, we sought to investigate whether diaspirin-crosslinked hemoglobin (DCLHb) can reduce the perioperative use of allogeneic blood transfusion. One-hundred-eighty-one elective surgical patients were enrolled at 19 clinical sites from 1996 to 1998. Selection criteria included anticipated transfusion of 2-4 blood units, aortic repair, and major joint or abdomino-pelvic surgery. Once a decision to transfuse had been made, patients received initially up to 3 250-mL infusions of 10% DCLHb (n = 92) or 3 U of packed red blood cells (PRBCs) (n = 89). DCLHb was infused during a 36-h perioperative window. On the day of surgery, 58 of 92 (64%; confidence interval [CI], 54%-74%) DCLHb-treated patients received no allogeneic PRBC transfusions. On Day 1, this number was 44 of 92 (48%; CI, 37%-58%) and decreased further until Day 7, when it was 21 of 92 (23%; CI, 15%-33%). During the 7-day period, 2 (1-4) units of PRBC per patient were used in the DCLHb group compared with 3 (2-4) units in the control patients (P = 0.002; medians and 25th and 75th percentiles). Mortality (4% and 3%, respectively) and incidence of suffering at least one serious adverse event (21% and 15%, respectively) were similar in DCLHb and PRBC groups. The incidence of jaundice, urinary side effects, and pancreatitis were more frequent in DCLHb patients. The study was terminated early because of safety concerns. Whereas the side-effect profile of modified hemoglobin solutions needs to be improved, our data show that hemoglobin solutions can be effective at reducing exposure to allogeneic blood for elective surgery. ⋯ In a randomized, double-blinded red blood cell controlled, multicenter trial, diaspirin-crosslinked hemoglobin spared allogeneic transfusion in 23% of patients undergoing elective noncardiac surgery. The observed side-effect profile indicates a need for improvement in hemoglobin development.
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Anesthesia and analgesia · Aug 2003
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of three different concentrations of levobupivacaine for caudal block in children.
We investigated three different concentrations of levobupivacaine (0.125%, 0.20%, and 0.25%; n = 20 in each group) for caudal blockade in a prospective, randomized, observer-blinded fashion in children (1-7 yr) undergoing subumbilical surgery. The duration of postoperative analgesia was assessed as the time to first administration of supplemental analgesia (based on a Childrens and Infants Postoperative Pain Scale score of >or=4), and the degree of immediate postoperative motor blockade was determined by use of a 3-point scale. A dose-response relationship was observed both with regard to median duration of postoperative analgesia (0.125%, 60 min; 0.20%, 118 min; 0.25%, 158 min) and the number of patients with evidence of early postoperative motor blockade (0.125%, 0; 0.20%, 4; 0.25%, 8). The 0.125% concentration was associated with significantly less early motor blockade (P = 0.003) but was found to result in a significantly shorter duration of postoperative analgesia (P < 0.05). Based on these results, the use of 0.20% levobupivacaine might represent the best clinical option if a plain levobupivacaine solution is to be used for caudal blockade in children. ⋯ The use of 0.125% levobupivacaine for caudal blockade (1 mL/kg) in children (1-7 yr) was associated with less early postoperative motor blockade but a shorter duration of postoperative analgesia compared with 0.20% and 0.25% solutions.
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Anesthesia and analgesia · Aug 2003
Randomized Controlled Trial Clinical TrialThe effect of exogenous epinephrine on the incidence of hypotensive/bradycardic events during shoulder surgery in the sitting position during interscalene block.
Sudden hypotensive and/or bradycardic events (HBE) have been reported in 13%-28% of patients undergoing shoulder surgery in the sitting position during interscalene block. The Bezold-Jarisch reflex is the most likely mechanism for these events. It has been hypothesized that exogenous epinephrine might be a key component to the occurrence of HBE. We conducted this prospective, randomized study to verify this hypothesis. Patients received a local anesthetic solution with (Group E; n = 55) or without (Group P; n = 55) epinephrine for interscalene block; no further exogenous epinephrine was administered. Blood pressure control was achieved with IV urapidil, a peripheral vasodilator, as needed. The incidence of HBE was 11% in Group P versus 29% in Group E (P = 0.015). Increased intraoperative heart rate and arterial blood pressure were recorded in Group E (P = 0.000). Urapidil was administered to 13% of Group P and to 31% of Group E patients (P = 0.018). Urapidil administration induced a HBE in 4% of Group P and in 5% of Group E patients. We conclude that exogenous epinephrine is involved in the development of HBE in this setting. ⋯ Sudden hypotensive and/or bradycardic events occur during shoulder surgery in the sitting position during interscalene block. In this study, we demonstrated that the presence of epinephrine in the local anesthetic mixture significantly increases the incidence of these events.