Home About us Contact
|
Home About us Contact | ||
|
|
||
Systolic Arterial Pressure (systolic + arterial_pressure)
Selected AbstractsDiabetes-induced Alterations in Latissimus Dorsi Muscle Properties Impair Effectiveness of Dynamic Cardiomyoplasty in RatsARTIFICIAL ORGANS, Issue 4 2004Kátia De Angelis Abstract:, Short-term diabetes was induced in male Wistar rats with streptozotocin injection. The effects of diabetes on latissimus dorsi (LD) muscle contractile and biochemical properties and acute cardiomyoplasty (CDM) were assessed and compared with data from 16 control rats. Isometric force, contractile properties, and fatigue were measured in electrically stimulated muscles (0.3 ms, 1,256 Hz), and Na+K+ and Ca2+ATPase activities were quantified in muscle membrane preparations. Systolic arterial pressure and aortic blood flow were recorded at rest and during LD muscle stimulation. Compared with control muscle, diabetic muscle showed smaller maximum specific tetanic tension and lower rates of rise and fall in force. Diabetic LD muscle also showed lower muscle enzyme activities. Twitch tension and fatigue did not differ between groups. Smaller increases in aortic flow and systolic pressure after CDM were found in diabetic rats compared to controls. The marked decrease in CDM effectiveness in diabetic rats likely reflected the alterations in muscle properties associated with diabetes. [source] Increased arterial pressure is not predictive of haemodynamic instability in patients undergoing adrenalectomy for phaeochromocytomaACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2009C. LENTSCHENER Background: Pre-operative hypotensive drugs are assumed to have dramatically decreased operative mortality and morbidity in patients undergoing phaeochromocytoma removal only in non-controlled studies. We evaluated the predictive value of pre-operative high systolic arterial pressure (SAP) on intra- and post-operative haemodynamic instability, in 96 patients undergoing laparoscopic adrenalectomy for phaeochromocytoma. Methods: Ninety-six consecutive patients underwent laparoscopic adrenalectomy for phaeochromocytoma. Pre-operative SAP was not systematically normalised, provided that increased SAP was clinically tolerated. Intravenous nicardipine, esmolol and norepinephrine were intraoperatively titrated to treat SAP increase >150 mmHg, tachycardia >90,110/min, arrhythmia or SAP decrease under 90 mmHg, respectively. Volume expanders were not systematically administered. Patients with increased and normal pre-operative SAP were compared with respect to (a) nicardipine, esmolol and norepinephrine requirement, (b) highest intraoperative SAP and heat rate, (c) lowest intraoperative SAP, (d) duration of surgery and (e) norepinephrine requirement following tumour removal. Results: Groups did not differ significantly with respect to data defined as being indicative of perioperative haemodynamic instability (all P values>0.05). Discussion: As previously demonstrated, in patients undergoing phaeochromocytoma removal, perioperative haemodynamic changes are mainly due to catecholamine release during tumour manipulation, and to the decrease in catecholamine level following tumour removal. Whether pre-operative hypotensive drugs are likely to alter these changes remains questionable. Conclusion: For most patients scheduled for laparoscopic phaeochromocytoma removal, surgery can be carried out without systematic pre-operative arterial pressure normalisation. [source] Effect of mivazerol, a ,2 -agonist, on striatal norepinephrine concentration during transient forebrain ischemia in rats,ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2008T. KIMURA Background: We have previously reported that mivazerol, a ,2 -agonist, possibly provides neuroprotection against transient forebrain ischemia in rats. This study was designed to investigate the ability of mivazerol to attenuate ischemia-induced increase in striatal norepinephrine concentration after transient forebrain ischemia in rats. Methods: Male Sprague,Dawley rats, anesthetized with halothane, were assigned to one of three groups (n=10 each); control (C, normal saline 1 ml/kg), mivazerol 20 ,g/kg (M20), and 40 ,g/kg (M40) groups. Monitored variables included temporal muscle temperature (maintained at 37.5±0.1 °C), electroencephalogram, systolic/diastolic blood pressure, heart rate, arterial blood gases, and blood glucose concentrations. Thirty minutes after subcutaneous drug administration, forebrain ischemia was induced with hemorrhagic hypotension (systolic arterial pressure: 40,50 mmHg) and bilateral carotid artery occlusion for 10 min, and then the brain was reperfused. Norepinephrine concentration in the interstitial fluids in the striatum was analyzed using in vivo microdialysis in combination with high-performance liquid chromatography. Results: Ischemia resulted in a prompt increase in norepinephrine concentrations in the striatum in all groups. However, there were no significant differences in norepinephrine concentrations in the striatum between the three groups at any period. Conclusions: Our results indicate that mivazerol did not attenuate ischemia-induced increase in striatal norepinephrine concentration. This suggests that the possible neuroprotective property of mivazerol is not related to inhibition of norepinephrine release in the brain. [source] Dexmedetomidine or medetomidine premedication before propofol,desflurane anaesthesia in dogsJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2006R. J. GÓMEZ-VILLAMANDOS The objective of this study was to evaluate dexmedetomidine as a premedicant in dogs prior to propofol,desflurane anaesthesia, and to compare it with medetomidine. Six healthy dogs were anaesthetized. Each dog received intravenously (i.v.) five preanaesthetic protocols: D1 (dexmedetomidine, 1 ,g/kg, i.v.), D2 (dexmedetomidine, 2 ,g/kg, i.v.), M1 (medetomidine, 1 ,g/kg, i.v.), M2 (medetomidine, 2 ,g/kg, i.v.), or M4 (medetomidine, 4 ,g/kg, i.v.). Anaesthesia was induced with propofol (2.3,3.3 mg/kg) and maintained with desflurane. The following variables were studied: heart rate (HR), mean arterial pressure, systolic arterial pressure, diastolic arterial pressure, respiratory rate (RR), arterial oxygen saturation, end-tidal CO2, end-tidal concentration of desflurane (EtDES) required for maintenance of anaesthesia and tidal volume. Arterial blood pH (pHa) and arterial blood gas tensions (PaO2, PaCO2) were measured during anaesthesia. Time to extubation, time to sternal recumbency and time to standing were also recorded. HR and RR decreased significantly during sedation in all protocols. Cardiorespiratory variables during anaesthesia were statistically similar for all protocols. EtDES was significantly different between D1 (8.1%) and D2 (7.5%), and between all doses of medetomidine. Desflurane requirements were similar for D1 and M2, and for D2 and M4 protocols. No statistical differences were observed in recovery times. The combination of dexmedetomidine, propofol and desflurane appears to be effective for induction and maintenance of general anaesthesia in healthy dogs. [source] Monitoring of end-tidal carbon dioxide partial pressure changes during infrarenal aortic cross-clamping: a non-invasive method to predict unclamping hypotensionACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2001G. Boccara Background: To assess the variations in end-tidal CO2 in response to aortic cross-clamping and the relationship with systolic arterial pressure (SAP) changes induced by unclamping. Methods: Thirty-three patients undergoing infrarenal aortic abdominal aneurysm repair by aorto-aortic prothetic bypass were prospectively studied. All patients were anesthetized with iv midazolam (0.05 mg · kg,1), thiopentone (3,5 mg · kg,1), fentanyl (5 ,g · kg,1), pancuronium (0.1 mg · kg,1) and the maintainance of anesthesia used was 1,1.5% end-tidal isoflurane and iv fentanyl. The perioperative management was standardized. End-tidal CO2 and SAP were measured 5 min before (Pre-XAA), 15 min after infrarenal aortic cross-clamping (XAA), 5 min before (Pre-UXAA) and immediately after unclamping (UXAA). Results: A total of 16 (48.5%) from 33 patients presented decrease in SAP following aortic unclamping, and 13 out of these patients had arterial hypotension defined as SAP <90 mmHg. End-tidal CO2 variation (PreXAA,PreUXAA) induced by aortic clamping was correlated with SAP variation (PreUXAA,UXAA) induced by unclamping (r=0.763; P=0.0001). An end-tidal CO2 reduction above 15% after aortic cross-clamping was found to have a 100% sensitivity to detect a SAP decrease greater than 20% after unclamping, with a 100% specificity and a negative predictive value of 1.0. Complete aortic occlusion duration was not correlated to SAP unclamping variation (,SAP). Intraoperative characteristics (fluid loading, hematocrits, urinary output) were comparable, although blood loss was higher in patients experiencing ,SAP>20%. Conclusions: End-tidal CO2 variation monitoring during aortic cross-clamping may provide a reliable and non-invasive method to predict unclamping hypotension. When the aortic clamp was released, systolic hypotension (>20%) occurred in those subjects who had a decrease in end-tidal CO2 greater than 15% during aortic cross-clamping. [source] Propofol,ketamine vs propofol,fentanyl combinations for deep sedation and analgesia in pediatric patients undergoing burn dressing changes,PEDIATRIC ANESTHESIA, Issue 1 2008ZEYNEP TOSUN MD Summary Background:, The aim of this study was to compare propofol,ketamine (PK) and propofol,fentanyl (PF) combinations for deep sedation and analgesia in pediatric burn wound dressing changes. Methods:, Thirty-two ASA physical status II and III inpatients with a second degree total burn surface area ranging from 5% to 25% were studied in a randomized, double blind fashion. Heart rate, systolic arterial pressure, peripheral oxygen saturation, respiratory rate and Ramsey sedation scores of all patients were recorded perioperatively. Patients were randomly assigned to receive either PK or PF: PK group (n = 17) received 1 mg·kg,1 ketamine + 1.2 mg·kg,1 propofol, and PF group (n = 15) received 1 ,g·kg,1 fentanyl + 1.2 mg·kg,1 propofol for induction. Additional propofol (0.5,1 mg·kg,1) was administered when the patients showed discomfort in both groups. If the patient showed discomfort and/or increase in heart rate or systolic arterial pressure, despite additional propofol dose, additional bolus of 0.5,1 mg·kg,1 ketamine or 0.5,1 ,g·kg,1 fentanyl was administered. Results:, There were no significant differences in heart rate, systolic arterial pressure, peripheral oxygen saturation, respiratory rate and sedation scores during the procedure between the groups. Restlessness during the procedure was seen in seven (47%) patients in Group PF and one (5.9%) patient in Group PK (P = 0.013). Conclusions:, Both propofol,ketamine and propofol,fentanyl combinations provided effective sedation and analgesia during dressing changes in pediatric burn patients. But propofol,ketamine combination was superior to propofol,fentanyl combination because of more restlessness in patients given propofol,fentanyl. [source] Assessing the clinical or pharmaco-economical benefit of target controlled desflurane delivery in surgical patients using the Zeus® anaesthesia machine,ANAESTHESIA, Issue 11 2009B. Lortat-Jacob Summary The Zeus® anaesthesia machine includes an auto-control mode which allows targeting of end-tidal volatile and inspired oxygen concentrations. We assessed the clinical benefits and economic impact of this target-controlled anaesthesia compared with conventional manually controlled anaesthesia. Eighty patients were randomly assigned to receive desflurane either with a fresh gas flow set by the anaesthetist or in auto-control mode. Drug delivery was adjusted to maintain bispectral index between 40,60 units and systolic arterial pressure under 15 mmHg above its pre-induction value (upper limit) and over 90 mmHg (lower limit). Blood pressure was maintained in the desired range for 89% and 91% of the maintenance period for auto-control and manual control respectively (p = 0.49). Bispectral index was in the desired range for 82% and 79% of the maintenance period, for auto-control and manual control respectively (p = 0.46). Oxygen consumption was more than halved by the use of auto-control mode, and mean (SD) desflurane consumption during surgery was 0.07 (0.04) vs 0.2 (0.07) ml.min,1 in auto-control and manual control respectively (p < 0.0001). The number of drug delivery adjustments per hour was significantly lower in auto-control mode (mean (SD) 7 (2) vs 15 (12); p < 0.0001). Thus, the auto-control mode provided similar haemodynamic stability and bispectral control as did conventional manually controlled anaesthesia, but led to a reduction in gas and vapour consumption with a more clinically acceptable workload. [source] Triggering of systolic arterial pressure alarms using statistics-based versus threshold alarms,ANAESTHESIA, Issue 2 2009C. W. Connor Summary Threshold systolic arterial pressure alarms often use pre-operative values as a guide for intra-operative values. Recently, two systems (normalisation and principal component analysis) have been described that use the ,current' systolic arterial pressure and the change in systolic arterial pressure over a preceding time interval to generate an alarm based on units of standard deviation. Normalisation and principal component analysis techniques should prioritise alarms for clinically significant changes and hence reduce overall activation of alarms. Our aim was to measure the change in alarm activation using these techniques compared with standard threshold alarms. Systolic blood pressure data, collected from 10 patients (a total of 2177 min at 100 Hz), were cleaned and submitted to analysis using threshold alarms, normalisation and principal component analysis. With the threshold alarms set at 100 mmHg (low) and 140 mmHg (high), and a 5-min window, the alarms were activated for 557 min; using statistics-based thresholds the alarms were activated for 169 min (normalisation) and 155 min (principal component analysis), a reduction of approximately 70,72%. [source] Baroreflex Sensitivity: Measurement and Clinical ImplicationsANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2008Maria Teresa La Rovere M.D. Alterations of the baroreceptor-heart rate reflex (baroreflex sensitivity, BRS) contribute to the reciprocal reduction of parasympathetic activity and increase of sympathetic activity that accompany the development and progression of cardiovascular diseases. Therefore, the measurement of the baroreflex is a source of valuable information in the clinical management of cardiac disease patients, particularly in risk stratification. This article briefly recalls the pathophysiological background of baroreflex control, and reviews the most relevant methods that have been developed so far for the measurement of BRS. They include three "classic" methods: (i) the use of vasoactive drugs, particularly the ,-adrenoreceptor agonist phenylephrine, (ii) the Valsalva maneuver, which produces a natural challenge for the baroreceptors by voluntarily increasing intrathoracic and abdominal pressure through straining, and (iii) the neck chamber technique, which allows a selective activation/deactivation of carotid baroreceptors by application of a negative/positive pressure to the neck region. Two more recent methods based on the analysis of spontaneous oscillations of systolic arterial pressure and RR interval are also reviewed: (i) the sequence method, which analyzes the relationship between increasing/decreasing ramps of blood pressure and related increasing/decreasing changes in RR interval through linear regression, and (ii) spectral methods, which assess the relationship (in terms of gain) between specific oscillatory components of the two signals. The limitations of the coherence criterion for the computation of spectral BRS are discussed, and recent proposals for overcoming them are presented. Most relevant clinical applications of BRS measurement are finally reviewed with particular reference to patients with myocardial infarction and heart failure. [source] The comparison of vitamin C and vitamin E on the protein oxidation of diabetic ratsAUTONOMIC & AUTACOID PHARMACOLOGY, Issue 5 2001H. D. Je Summary 1 We measured the plasma glucose and the glycosylated haemoglobin at the time of sacrifice in streptozotocin-induced diabetic mellitus (DM) rats. 2 In diabetic rats, plasma glucose and glycosylated haemoglobin was increased as compared with normal rats, and vitamin E inhibited the increase of glycosylated haemoglobin level but vitamin C had no effect. 3 The peroxidized proteins and lipids from the diabetic organs such as liver or kidney were measured to assess the oxidative damage. The 2,4-dinitrophenyl-hydrazine (DNPH) incorporation method was used to measure the peroxidized protein. In diabetic rats, DNPH incorporation was increased as compared with normal rats and vitamin E also inhibited the increase of DNPH incorporation but vitamin C had no effect. It suggests that the protein oxidation occurred on the liver in diabetic rats and the oxidative stress is general in the diabetic condition. 4 We measured the systolic arterial pressure and mean arterial pressure in normal rats, nephrectomy (NEPH)-rats, diabetic rats (DM), and NEPH-diabetic rats (NEPH-DM). Blood pressure was significantly increased in DM and NEPH-DM as compared with normal rats. 5 In conclusion, plasma glucose, glycosylated haemoglobin, and the oxidation of proteins or lipid were increased in diabetic rats. Vitamin E decreased the plasma glucose, glycosylated haemoglobin and the oxidation of proteins and lipid, but vitamin C had no effects. [source] Relevance of anaesthesia for dofetilide-induced torsades de pointes in ,1 -adrenoceptor-stimulated rabbitsBRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2008D Vincze Background and purpose: No information is available concerning the effects of anaesthetics in the most frequently used in vivo pro-arrhythmia model. Accordingly, in this study we examined the effect of pentobarbital, propofol or ,-chloralose anaesthesia on the pro-arrhythmic activity of the class III anti-arrhythmic dofetilide in ,1 -adrenoceptor-stimulated rabbits. Experimental approach: Rabbits anaesthetized intravenously with pentobarbital, propofol or ,-chloralose were infused simultaneously with the ,1 -adrenoceptor agonist phenylephrine (15 ,g kg,1 min,1, i.v.) and dofetilide (0.04 mg kg,1 min,1, i.v.). The electrocardiographic QT interval, the Tpeak,Tend interval and certain QT variability parameters were measured. The heart rate variability and the baroreflex sensitivity were utilized to assess the vagal nerve activity. The spectral power of the systolic arterial pressure was calculated in the frequency range 0.15,0.5 Hz to assess the sympathetic activity. Key results: Pentobarbital considerably reduced, whereas propofol did not significantly affect the incidence of dofetilide-induced torsades de pointes (TdP) as compared with the results with ,-chloralose (40% (P=0.011) and 70% (P=0.211) vs 100%, respectively). In additional experiments, neither doubling of the rate of the dofetilide infusion nor tripling of the rate of phenylephrine infusion elevated the incidence of TdP to the level seen with ,-chloralose. None of the repolarization-related parameters predicted TdP. The indices of the parasympathetic and sympathetic activity were significantly depressed in the ,-chloralose and propofol anaesthesia groups. Conclusions and implications: In rabbits, anaesthetics may affect drug-induced TdP genesis differently, which must be considered when results of different studies are compared. British Journal of Pharmacology (2008) 153, 75,89; doi:10.1038/sj.bjp.0707536; published online 29 October 2007 [source] Respiratory effects on the reproducibility of cardiovascular autonomic parametersCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 4 2007Éva Zöllei Summary The aim of this study was to assess the influence of breathing pattern on the reproducibility of the most commonly used heart rate and blood pressure variability parameters and baroreflex indices. 5,5 min ECG and blood pressure recordings were made and repeated for 10 healthy volunteers in supine rest on 10 consecutive days during spontaneous and 6 min,1 patterned breathing. We investigated the following parameters: mean RR interval (RRI); the standard deviation of RR intervals (SDRR); the root mean square of successive differences in RRI (RMSSD); the percentage of RRIs which differed by 50% from the proceeding RRI (PNN50); mean systolic arterial pressure (SAP); the standard deviation of SAP (SAP SD); mean mean arterial pressure (MAP); mean diastolic blood pressure (DAP) and baroreflex indices from spontaneous sequence method (upBRS and downBRS) and from cross spectral analysis (LF alpha, HF alpha). To assess reproducibility for each parameter within- and between-subject variability values were calculated and the ratio of within- and between-subject variability was assessed. In addition, we calculated intraclass correlation coefficient (ICC). Compared to spontaneous respiration during 6 min,1 patterned breathing the heart rate and blood pressure variability increased; upBRS, LF alpha and HF alpha increased, downBRS did not change. However, ICC showed good reproducibility for most parameters, which did not improve further with controlled breathing. In conclusion, respiration had a strong influence on the most widely used cardiovascular autonomic parameters. The controlling of breathing did not result in consistent improvement in their reproducibility. [source] Enalapril/amlodipine combination in cyclosporine-treated renal transplant recipients: a prospective randomized trialCLINICAL TRANSPLANTATION, Issue 2 2007Jean-Michel Halimi Abstract:, Background:, Most hypertensive renal transplant recipients require two or more antihypertensive medications to achieve blood pressure control. However, which medications must be combined is still a matter of debate. Methods:, A prospective randomized open-label blinded evaluation trial comparing the six-month effects of the amlodipine,enalapril combination (n = 32) vs. enalapril alone (n = 33) and vs. amlodipine alone (n = 34) on arterial pressure, renal function, albuminuria and tolerability. Results:, At six months, diastolic arterial pressure was more adequately controlled (i.e., <90 mmHg) in the combination group than in the amlodipine and enalapril groups (100% vs. 82.4% and 84.8%, respectively, p = 0.038). The same trend was observed for systolic arterial pressure (65.6% vs. 58.8% and 51.5%, NS). The six-month change in albuminuria was similar in the combination group and in the enalapril group (,64.7% vs. ,59.5%); however, patients in the combination group exhibited a greater reduction in albuminuria than in the amlodipine group (,64.7% vs. ,29.0%, p = 0.002). As compared with baseline values, serum creatinine and potassium remained unchanged in the combination group, whereas they increased by 9 ± 12 ,mol/L (p = 0.01) and by 0.2 ± 0.4 mmol/L (p < 0.01), respectively, in the enalapril group. The cyclosporine trough levels remained unchanged in the combination group, but increased in the amlodipine group. Conclusion:, Angiotensin-converting enzyme inhibitor (ACEI),calcium-channel blocker (CCB) combination controls arterial pressure more adequately than ACEI alone or CCB alone, reduces albuminuria and may prevent the ACEI-induced initial rise in serum creatinine. [source] | ||||||||||||||||||||||