Anesthesia and analgesia
-
Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Clinical TrialA placebo-controlled randomized crossover trial of the N-methyl-D-aspartic acid receptor antagonist, memantine, in patients with chronic phantom limb pain.
In the present study we investigated the effect of the N-methyl-D-aspartic acid (NMDA) receptor antagonist memantine (30 mg/d) on the intensity of chronic phantom limb pain (PLP) and cortical reorganization. In 8 patients with chronic PLP, memantine was tested in a placebo-controlled double-blinded crossover trial of 4 wk duration per trial. The intensity of PLP was rated hourly by the patients on a visual analog scale during baseline and both treatment periods. At the same time points, the functional organization of the primary somatosensory cortex (SI) was determined by neuromagnetic source imaging. In comparison to baseline and placebo, the NMDA receptor antagonist had no effect on the intensity of chronic PLP. In none of the periods were significant changes in the functional organization of SI observed. Although the conclusions regarding the clinical effect are limited because of the small sample size, the data indicate that in the studied dosage the NMDA receptor antagonist memantine is ineffective in the treatment of chronic PLP and is also ineffective for the reduction of associated neural plasticity in the primary SI. ⋯ NMDA receptors play a substantial role in central nervous system changes underlying neuropathic pain. In a placebo-controlled double-blinded study we tested the effect of 30 mg memantine on chronic phantom limb pain and pain-associated cortical reorganization.
-
Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Clinical TrialHeparin-level-based anticoagulation management during cardiopulmonary bypass: a pilot investigation on the effects of a half-dose aprotinin protocol on postoperative blood loss and hemostatic activation and inflammatory response.
Cardiac surgery involving cardiopulmonary bypass (CPB) leads to activation of the hemostatic/inflammatory system. We compared the influence of a half-dose aprotinin regimen on postoperative blood loss and the activation of the hemostatic/inflammatory system during CPB, when used during a heparin-level-based heparin management for cardiac surgery. Two-hundred patients (n = 100 in each group) were enrolled in this randomized prospective study. In Group I only heparin was given according to the results of the Hepcon HMS Plus. In Group II aprotinin was added with a bolus of 1 x 10(6) kallikrein inhibiting units (KIU) for the patient immediately before initiation of CPB, 1 x 10(6) KIU in the priming solution of the CPB, and a continuous infusion of 250,000 KIU/h during CPB. Postoperative blood loss was determined after 12 h. Heparin and antithrombin activity were evaluated by an anti-Xa assay and measurement of antithrombin III activity. Hemostatic activation was evaluated by adenosine diphosphate-stimulated platelet aggregometry and by measurements of the generation/release of beta-thromboglobulin (beta-TG), soluble P-selectin (sPS), thrombin (TAT), prothrombin 1 and 2 fragments (PTF1+2), factor XIIa (FXIIa), plasmin (PAP), and D-dimers. Inflammatory response was evaluated by measuring complement factors 5b-9 (C5b-9), interleukin (IL)-6, and neutrophil elastase (NE). There were no differences in the pre-CPB values or duration of CPB between the two groups. There were no differences in the post-CPB values for platelet count, platelet aggregation, beta-TG, sPS, TAT, PTF1+2, C5b-9, NE, or IL-6. The additional use of aprotinin resulted in a significant decrease of PAP, D-dimers, and 12 h postoperative blood loss, whereas generation of the contact factor XIIa was increased. The administration of aprotinin significantly reduced postoperative blood loss after cardiac surgery and CPB. This most likely has to be attributed to the antifibrinolytic effects of aprotinin. No effects on thrombin generation, platelet activation, inflammatory response, or clinical outcome were noted. ⋯ The use of half-dose aprotinin and heparin-level-based anticoagulation management during cardiopulmonary bypass leads to a significant reduction of postoperative blood loss after cardiac surgery. This effect can most likely be attributed to the antifibrinolytic effects of aprotinin, as we did not observe effects on other variables of activation of the hemostatic/inflammatory system.
-
Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Clinical TrialHydroxyethyl starch as a priming solution for cardiopulmonary bypass impairs hemostasis after cardiac surgery.
We investigated the influence of hydroxyethyl starch (HES) as a priming solution for the cardiopulmonary bypass (CPB) circuit on postoperative hemostasis in 45 patients undergoing elective coronary artery bypass grafting. In a randomized sequence, 20 mL/kg of low-molecular-weight HES (HES 120; molecular weight 120,000 daltons), high-molecular-weight HES (HES 400; molecular weight 400,000 daltons), or 4% human albumin (ALB) was used as the main component of the CPB priming solution. The thromboelastographic values indicating the speed of solid clot formation (alpha-angle) and the strength of the fibrin clot (maximum amplitude and shear elastic modulus) were decreased up to 2 h after CPB in both HES groups. Four hours after the operation, blood loss through the chest tubes had increased in the HES groups: HES 120, mean 804 mL (range, 330-1390 mL); HES 400, mean 1008 mL (range, 505-1955 mL); and ALB, mean 681 mL (range, 295-1500 mL) (P < 0.05 between the HES 400 and ALB groups). We conclude that HES solutions, when given in doses of 20 mL/kg in connection with the CPB prime, compromise hemostasis after cardiac surgery. This effect appears related to formation of a less stable thrombus compared with that formed in the presence of ALB. ⋯ The influence of hydroxyethyl starch (HES) on postoperative hemostasis was investigated in cardiac surgery. The thromboelastographic values indicated that HES solutions, when given in connection with the cardiopulmonary bypass prime, compromise hemostasis after cardiac surgery. This effect seems to occur through the formation of a less stable clot.
-
Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Clinical TrialThe effect of music on the neurohormonal stress response to surgery under general anesthesia.
Several pharmacological interventions reduce perioperative stress hormone release during surgery under general anesthesia. Listening to music and therapeutic suggestions were also studied, but mostly in awake patients, and these have a positive effect on postoperative recovery and the need for analgesia. In this study, we evaluated the effect of listening to music under general anesthesia on the neurohormonal response to surgical stress as measured by epinephrine, norepinephrine, cortisol, and adrenocorticotropic hormone (ACTH) blood levels. Thirty female patients scheduled for abdominal gynecological procedures were enrolled and randomly divided into two groups: group NM (no music) and group M (music). In group M, music was played from after the induction of anesthesia until the end of surgery. In the NM group, the patients wore the headphones but no music was played. We established three sample times for hormonal dosage during the procedure and one in the recovery room. Hemodynamic data were recorded at all times, and postoperative consumption of morphine in the first 24 h was noted. There was no group difference at any sample time or in the postoperative period in terms of mean arterial blood pressure, heart rate, isoflurane end-tidal concentration, time of the day at which the surgery was performed, bispectral index (BIS) value, doses of fentanyl, or consumption of postoperative morphine. There was no difference between the two groups with regard to plasmatic levels of norepinephrine, epinephrine, cortisol, or ACTH at any sample time, although the blood level of these hormones significantly increased in each group with surgical stimulation. In conclusion, we could not demonstrate a significant effect of intraoperative music on surgical stress when used under general anesthesia. ⋯ Listening to music under general anesthesia did not reduce perioperative stress hormone release or opioid consumption in patients undergoing gynecological surgery.
-
Anesthesia and analgesia · Feb 2004
Clinical TrialIncreases in P-wave dispersion predict postoperative atrial fibrillation after coronary artery bypass graft surgery.
Atrial fibrillation (AF) is a common complication after coronary artery bypass graft (CABG) surgery. In this study we examined the effect of surgery on atrial electrophysiology as measured by P-wave characteristics and to determine the potential predictive value of P-wave characteristics on the incidences of postoperative AF in patients undergoing CABG surgery. Patients undergoing elective CABG surgery were monitored by continuous electrocardiogram (ECG) telemetry during the in-hospital period until discharge for the occurrence of postoperative AF. Differences in P-wave characteristics (P-wave duration, amplitude, axis, dispersion, PR interval, segment depression, and dispersion) were compared between the pre- and postoperative 12-lead ECG measurements, and also between patients with and without postoperative AF. The association of postoperative AF and potential clinical predictors and P-wave characteristics were determined by multivariate logistic regression. Postoperative AF occurred in 81 (27%) of 300 patients. Univariate analysis showed that patients who subsequently developed postoperative AF compared with those without AF were significantly older (mean age 68 +/- 8 versus 63 +/- 10 yr, P < 0.0001), had a larger body surface area (BSA) (2.03 +/- 0.24 versus 1.92 +/- 0.22 m(2), P = 0.0002), were more likely to have a history of AF (8 of 81 versus 1 of 219, P = 0.003), used preoperative antiarrhythmic medications more frequently (7 of 81 versus 4 of 219, P = 0.01), and had a more frequent rate of return to the operating room for postoperative complications (9 of 81 versus 9 of 219, P = 0.029). Furthermore, the postoperative P-wave duration decreased to a larger extent (mean change -11.3 +/- 0.1 ms versus -8.4 +/- 0.1 ms, P < 0.0001), and the P-wave dispersion increased postoperatively to a larger extent (3.1 +/- 15.5 ms versus -1.6 +/- 14.6 ms, P = 0.028) in those who subsequently developed AF compared with those without AF. Multivariate logistic regression showed age (odds ratio [OR] = 1.1, 95% confidence interval [CI]: 1.06-1.15, P < 0.0001), BSA (OR = 38.1, 95% CI: 8.2-176, P < 0.0001), and an increase in postoperative P-wave dispersion (OR = 1.03, 95% CI: 1.01-1.05, P = 0.01) to be independent predictors of postoperative AF. No surgical factor was identified to be responsible for this postoperative change in atrial electrophysiology. ⋯ In addition to clinical factors, such as advanced age and body surface area, we demonstrated that electrophysiologic changes involving an increase in P-wave dispersion postoperatively independently predict atrial fibrillation after coronary artery bypass graft surgery.