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Constant Rate Infusion (constant + rate_infusion)
Selected AbstractsComparison of cardiovascular function and quality of recovery in isoflurane-anaesthetised horses administered a constant rate infusion of lidocaine or lidocaine and medetomidine during elective surgeryEQUINE VETERINARY JOURNAL, Issue 3 2010A. VALVERDE Summary Reasons for performing study: The effects of lidocaine combined with medetomidine or lidocaine alone on cardiovascular function during anaesthesia and their effects on recovery have not been thoroughly investigated in isoflurane-anaesthetised horses. Objectives: To determine the effects of an intraoperative i.v. constant rate infusion of lidocaine combined with medetomidine (Group 1) or lidocaine (Group 2) alone on cardiovascular function and on the quality of recovery in 12 isoflurane-anaesthetised horses undergoing arthroscopy. Hypothesis: The combination would depress cardiovascular function but improve the quality of recovery when compared to lidocaine alone in isoflurane-anaesthetised horses. Methods: Lidocaine (2 mg/kg bwt i.v. bolus followed by 50 µg/kg bwt/min i.v.) or lidocaine (same dose) and medetomidine (5 µg/kg bwt/h i.v.) was started 30 min after induction of anaesthesia. Lidocaine administration was discontinued 30 min before the end of surgery in both groups, whereas medetomidine administration was continued until the end of surgery. Cardiovascular function and quality of recovery were assessed. Results: Horses in Group 1 had longer recoveries, which were of better quality due to better strength and overall attitude during the recovery phase than those in Group 2. Arterial blood pressure was significantly higher in Group 1 than in Group 2 and this effect was associated with medetomidine. No significant differences in cardiac output, arterial blood gases, electrolytes and acid-base status were detected between the 2 groups. Conclusions and potential relevance: The combination of an intraoperative constant rate infusion of lidocaine and medetomidine did not adversely affect cardiovascular function in isoflurane-anaesthetised horses and improved the quality of recovery when compared to an intraoperative infusion of lidocaine alone. [source] Effects of postoperative ketamine infusion on pain control and feeding behaviour in bitches undergoing mastectomyJOURNAL OF SMALL ANIMAL PRACTICE, Issue 12 2007S. Sarrau Objectives: To determine if ketamine administered to bitches at the end of a mastectomy, followed by a six-hour constant rate infusion (CRI), improved postoperative opioid analgesia and feeding behaviour. Methods: The bitches were randomised into three groups: the placebo group received 0·09 ml/kg isotonic saline intravenously followed by a six-hour CRI of 0·5 ml/kg/hour, the low-dose ketamine received 150 ,g/kg ketamine intravenously followed by a six-hour CRI of 2 ,g/kg/minute and the high-dose ketamine group received 700 ,g/kg ketamine intravenously followed by a six-hour CRI of 10 ,g/kg/minute. Any additional opioids given were recorded at the time of extubation and at intervals after extubation. Food intake was evaluated eight (T8) and 20 (T20) hours after extubation by measuring the per cent coverage of basal energy requirements (BER). Results: No significant difference was observed for opioid requirements between the three groups. The mean percentages of BER coverage did not differ significantly at T8 but the difference between the high-dose and low-dose ketamine groups (P=0·014), and the high-dose ketamine and placebo groups (P=0·038) was significant at T20. Clinical Significance: This study demonstrated that 700 ,g/kg ketamine given intravenously postoperatively followed by a six-hour ketamine CRI of 10 ,g/kg/minute improved patient feeding behaviour. [source] Coagulation effects of low molecular weight heparin compared with heparin in dogs considered to be at risk for clinically significant venous thrombosisJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 1 2009Kielyn C. Scott DVM Abstract Objective , Compare the effects of 3 anticoagulation protocols on anti-factor Xa activity (AXa). Design , Prospective, randomized, double-blind study. Setting , University veterinary teaching hospital. Animals , Eighteen dogs considered to be at risk for venous thrombosis. Interventions , Each dog was randomly assigned to 1 of the following 3 groups (n=6/group) and was treated for 24 hours: low-dose heparin (LDH), high-dose heparin (HDH), and dalteparin (DP). Dogs in the LDH group received a constant rate infusion (CRI) of unfractionated heparin (UFH) at 300 U/kg/d, the HDH group received a bolus of 100 U/kg of UFH IV, then a CRI of 900 U/kg/day, and the DP group received 100 U/kg DP SC at 0, 12, and 24 hours. Measurements and Main Results , A total of 54 samples for activated partial thromboplastin time (aPTT) and AXa assays were collected at 0, 4, and 28 hours. Six samples had an AXa >0.1 U/mL, 5 of those were from the HDH group at hour 4. Two samples from the HDH group at hour 4 had a prolonged aPTT (93 and 200 seconds) and the highest AXa (0.6 and 1.0 U/mL, respectively). Four additional dogs in the HDH group did not complete the study due to hemorrhage; none of the dogs completing the study showed signs of hemorrhage. Conclusions: Neither DP nor LDH increased AXa to values considered therapeutic in humans (0.5,1 and 0.35,0.75 U/mL, respectively), and both protocols appear to be inadequate to increase AXa in dogs with clinical illness. HDH increased AXa to this range in 2 of 6 dogs, but had unpredictable effects on aPTT and resulted in hemorrhage in some dogs. [source] Atrial, SA Nodal, and AV Nodal Electrophysiology in Standing Horses: Normal Findings and Electrophysiologic Effects of Quinidine and DiltiazemJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2007Colin C. Schwarzwald Background: Although atrial arrhythmias are clinically important in horses, atrial electrophysiology has been incompletely studied. Hypotheses: Standard electrophysiologic methods can be used to study drug effects in horses. Specifically, the effects of diltiazem on atrioventricular (AV) nodal conduction are rate-dependent and allow control of ventricular response rate during rapid atrial pacing in horses undergoing quinidine treatment. Animals: Fourteen healthy horses. Methods: Arterial blood pressure, surface electrocardiogram, and right atrial electrogram were recorded during sinus rhythm and during programmed electrical stimulation at baseline, after administration of quinidine gluconate (10 mg/kg IV over 30 minutes, n = 7; and 12 mg/kg IV over 5 minutes followed by 5 mg/kg/h constant rate infusion for the remaining duration of the study, n = 7), and after coadministration of diltiazem (0.125 mg/kg IV over 2 minutes repeated every 12 minutes to effect). Results: Quinidine significantly prolonged the atrial effective refractory period, shortened the functional refractory period (FRP) of the AV node, and increased the ventricular response rate during atrial pacing. Diltiazem increased the FRP, controlled ventricular rate in a rate-dependent manner, caused dose-dependent suppression of the sinoatrial node and produced a significant, but well tolerated decrease in blood pressure. Effective doses of diltiazem ranged from 0.125 to 1.125 mg/kg. Conclusions and Clinical Importance: Standard electrophysiologic techniques allow characterization of drug effects in standing horses. Diltiazem is effective for ventricular rate control in this pacing model of supraventricular tachycardia. The use of diltiazem for rate control in horses with atrial fibrillation merits further investigation. [source] | ||||||||||