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Mean Arterial Blood Pressure (mean + arterial_blood_pressure)
Selected AbstractsCardiovascular Response to Graded Lower Body Negative Pressure in Young and Elderly ManEXPERIMENTAL PHYSIOLOGY, Issue 3 2001R. van Hoeyweghen Lower body negative pressure (LBNP) reduces central venous pressure (CVP) and cardiac output. The elderly are reported to have a limited capacity to increase cardiac output by increasing heart rate (HR), are especially dependent on end diastolic volume to maintain stroke volume and therefore should be especially vulnerable to LBNP. The present study compared the effects of LBNP in the young and old. Stroke volume was assessed non-invasively as stroke distance (SD) by aortovelography. Two groups of healthy male volunteers were studied: eight young (29.7 ± 2.0 years, mean ± S.E.M.) and nine old (70.1 ± 0.9 years). LBNP was applied progressively at 17.5, 35 and 50 mmHg in 20 min steps, with measurements taken during each steady state. There were similar, significant, falls in CVP in both groups. SD fell significantly in both groups from respective control values of 24.8 ± 1.6 and 16.6 ± 0.9 cm to 12.5 ± 1.3 and 8.9 ± 0.4 cm at a LBNP of 50 mmHg. Although SD in the elderly was significantly lower than in the young, the LBNP-induced changes were not different between groups. Both groups produced similar significant increases in vascular resistance, HR, plasma vasopressin (AVP) and noradrenaline. Mean arterial blood pressure (MBP) and plasma adrenaline did not change significantly. Therefore healthy old men respond to LBNP in a similar manner to the young, although MBP and SD are regulated around different baselines in the two groups. [source] Acute Alcohol Intoxication During Hemorrhagic Shock: Impact on Host Defense From InfectionALCOHOLISM, Issue 4 2004K. L. Zambell Abstract: Background: Acute alcohol intoxication is a frequent underlying condition associated with traumatic injury. Our studies have demonstrated that acute alcohol intoxication significantly impairs the immediate hemodynamic, metabolic, and inflammatory responses to hemorrhagic shock. This study investigated whether acute alcohol intoxication during hemorrhagic shock would alter the outcome from an infectious challenge during the initial 24 hr recovery period. Methods: Chronically catheterized male Sprague Dawley® rats were randomized to acute alcohol intoxication (EtOH; 1.75 g/kg bolus followed by a constant 15 hr infusion at 250,300 mg/kg/hr) or isocaloric isovolemic dextrose infusion (dex; 3 ml + 0.375 ml/hr). EtOH and dex were assigned to either fixed-volume (50%) hemorrhagic shock followed by fluid resuscitation with Ringer's lactate (EtOH/hem, dex/hem) or sham hemorrhagic shock (EtOH/sham, dex/sham). Indexes of circulating neutrophil function (apoptosis, phagocytosis, oxidative burst) were obtained at baseline, at completion of hemorrhagic shock, and at the end of fluid resuscitation. Bacterial clearance, lung cytokine expression, and myeloperoxidase activity were determined at 6 and 18 hr after an intratracheal challenge with Klebsiella pneumoniae (107 colony-forming units). Results: Mean arterial blood pressure was significantly lower in acute alcohol intoxication-hemorrhagic shock animals throughout the hemorrhagic shock. In sham animals, acute alcohol intoxication alone did not produce significant changes in neutrophil apoptosis or phagocytic activity but significantly suppressed phorbol myristic acid (PMA)-stimulated oxidative burst. Hemorrhagic shock produced a modest increase in neutrophil apoptosis and suppression of neutrophil phagocytic capacity but significantly suppressed PMA-stimulated oxidative burst. Acute alcohol intoxication exacerbated the hemorrhagic shock-induced neutrophil apoptosis and the hemorrhagic shock-induced suppression of phagocytosis without further affecting PMA-stimulated oxidative burst. Fluid resuscitation did not restore neutrophil phagocytosis or oxidative burst. Acute alcohol intoxication decreased (,40%) 3-day survival from K. pneumoniae in hemorrhagic shock animals, impaired bacterial clearance during the first 18 hr postinfection, and prolonged lung proinflammatory cytokine expression. Conclusions: These results demonstrate that the early alterations in metabolic and inflammatory responses to hemorrhagic shock produced by acute alcohol intoxication are associated with neutrophil dysfunction and impaired host response to a secondary infectious challenge leading to increased morbidity and mortality. [source] Dynamic cerebral autoregulation in healthy adolescentsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2002M. S. Vavilala Background: There is little information on the limits of cerebral autoregulation and the autoregulatory capacity in children. The aim of this study was to compare dynamic cerebral autoregulation between healthy adolescents and adults. Methods: Seventeen healthy volunteers 12,17 years (n = 8) and 25,45 years (n = 9) were enrolled in this study. Bilateral mean middle cerebral artery flow velocities (Vmca; (cm/s)) were measured using transcranial Doppler ultrasonography (TCD). Mean arterial blood pressure (MAP) and end-tidal carbon dioxide were measured continuously during dynamic cerebral autoregulation studies. Blood pressure cuffs were placed around both thighs and inflated to 30 mmHg above the systolic blood pressure for 3 min and then rapidly deflated, resulting in transient systemic hypotension. The change of Vmca to change in MAP constitutes the autoregulatory response, and the speed of this response was quantified using computer model parameter estimation. The dynamic autoregulatory index (ARI) was averaged between the two sides. Results: Adolescents had significantly lower ARI (3.9 ± 2.1 vs. 5.3 ± 0.8; P=0.05), and higher Vmca (75.2 ± 15.2 vs. 57.6 ± 15.0; P<0.001) than adults. Conclusion: The autoregulatory index is physiologically lower in normal adolescents 12,17 years of age than in adults. [source] Clinical Predictors of Proteinuria after Conversion to Sirolimus in Kidney Transplant RecipientsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2010A. Padiyar Proteinuria is an increasingly recognized effect of sirolimus (SRL) therapy in kidney transplant recipients. Predictors of proteinuria after conversion to SRL are not well described, and in particular the risk in African-American (AA) kidney recipients is unknown. We sought to analyze risk factors for proteinuria with SRL therapy in a cohort of 39 patients (44% AA) converted from tacrolimus to SRL at a mean time of 4 months posttransplantation. Patients were maintained on therapy with mycophenolate mofetil while most patients underwent early steroid withdrawal. Urinary protein to creatinine ratio (Up/cr) at a mean of 14 months postconversion increased to ,500 mg/g in 65% of AAs versus 14% of non-AAs (p = 0.001). Mean arterial blood pressure at the time of conversion and pretransplant proteinuric kidney disease were also predictors of proteinuria after SRL conversion. In conclusion, AAs appear to be at high risk for proteinuria and should be monitored closely after conversion to SRL in calcineurin inhibitor sparing protocols. [source] Differences between bispectral index and spectral entropy during xenon anaesthesia: a comparison with propofol anaesthesiaANAESTHESIA, Issue 6 2010J. Höcker Summary We enrolled 114 patients, aged 65,83 years, undergoing elective surgery (duration > 2h) into a randomised, controlled study to evaluate the performance of bispectral index and spectral entropy for monitoring depth of xenon versus propofol anaesthesia. In the propofol group, bispectral index and state entropy values were comparable. In the xenon group, bispectral index values resembled those in the propofol group, but spectral entropy levels were significantly lower. Mean arterial blood pressure was higher and heart rate was lower in the xenon group than in the propofol group. Bispectral index and spectral entropy considerably diverged during xenon but not during propofol anaesthesia. We therefore conclude that these measures are not interchangeable for the assessment of depth of hypnosis and that bispectral index is likely to reflect actual depth of anaesthesia more precisely compared with spectral entropy. [source] Effect of exposure to 50,Hz magnetic field with or without insulin on blood,brain barrier permeability in streptozotocin-induced diabetic rats,BIOELECTROMAGNETICS, Issue 4 2010Sefa Gulturk Abstract We investigated the effect of long-term exposure to modulation magnetic field (MF), insulin, and their combination on blood,brain barrier (BBB) permeability in a diabetic rat model. Fifty-three rats were randomly assigned to one of six groups: sham, exposed to no MF; MF, exposed to MF; diabetes mellitus (DM), DM induced with streptozotocin (STZ); DM plus MF (DMMF); DM plus insulin therapy (DMI); and DM plus insulin therapy plus MF (DMIMF). All the rats underwent Evans blue (EB) measurement to evaluate the BBB 30 days after the beginning of experiments. The rats in MF, DMMF, and DMIMF groups were exposed to MF (B,=,5,mT) for 165,min every day for 30 days. Mean arterial blood pressure (MABP), body mass, and serum glucose level of the study rats were recorded. The extravasation of brain EB of the MF, DM, DMMF, DMI, and DMIMF groups was higher than that of the sham group and the extravasation of right hemisphere of the DMIMF group was highest (P,<,0.05). The post-procedure body mass of the sham and MF groups were significantly higher than those of the DM and DMMF groups (P,<,0.05). In the DM, DMMF, DMI, and DMIMF groups, the baseline glucose was significantly lower than the post-procedure glucose (P,<,0.05). DM and MF increase BBB permeability; in combination, they cause more increase in BBB permeability, and insulin decreases their effect on BBB. Improved glucose metabolism may prevent body mass loss and the hypoglycemic effect of MF. DM increases MABP but MF causes no additional effect. Bioelectromagnetics 31:262,269, 2010. © 2009 Wiley-Liss, Inc. [source] Reciprocal regulation of human soluble and particulate guanylate cyclases in vivoBRITISH JOURNAL OF PHARMACOLOGY, Issue 6 2006M Madhani Background & purpose: We demonstrated previously that reciprocal regulation of soluble (sGC) and particulate (pGC) guanylate cyclases by NO and natriuretic peptides coordinates cyclic cGMP-mediated vasodilatation in vitro. Herein, we investigated whether such an interaction contributes to vascular homeostasis in mice and humans in vivo. Experimental approach: Mean arterial blood pressure (MABP) changes in anaesthetized mice were monitored in response to i.v. administration of cGMP- and cAMP-dependent vasodilators in wild-type (WT), endothelial NO synthase (eNOS) and natriuretic peptide receptor (NPR)-A knockout mice. Forearm blood flow (FBF) in response to intra-brachial infusion of ANP (25, 50, 100, 200 pmol min -1) in the absence and presence of the NOS inhibitor NG -methyl-L-arginine (L-NMA; 4 ,mol min -1) and the control constrictor noradrenaline (240 pmol min -1) was assessed in healthy volunteers. Key results: Sodium nitroprusside (SNP; NO-donor) and atrial natriuretic peptide (ANP) produced dose-dependent reductions in MABP in WT animals that were significantly enhanced in eNOS KO mice. In NPR-A K mice, SNP produced a dose-dependent reduction in MABP that was significantly greater than that in WT mice. Responsiveness to the cAMP-dependent vasodilator epoprostenol was similar in WT, eNOS KO and NPR-A KO animals. ANP caused vasodilatation of the forearm resistance vasculature that was significantly greater in individuals lacking endothelium-derived NO (i.e. L-NMA treated). Conclusions & implications: These data demonstrate that crosstalk occurs between the NO-sGC and ANP-pGC pathways to regulate cGMP-dependent vasodilatation in vivo in both mice and humans. These findings have implications for understanding the link between natriuretic peptide activity and cardiovascular risk. British Journal of Pharmacology (2006) 149, 797,801. doi:10.1038/sj.bjp.0706920 [source] Increased Cerebral Blood Flow And Cardiac Output Following Cerebral Arterial Air Embolism In SheepCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 11 2001David J Williams SUMMARY 1. The effects of cerebral arterial gas embolism on cerebral blood flow and systemic cardiovascular parameters were assessed in anaesthetized sheep. 2. Six sheep received a 2.5 mL injection of air simultaneously into each common carotid artery over 5 s. Mean arterial blood pressure, heart rate, end-tidal carbon dioxide and an ultrasonic Doppler index of cerebral blood flow were monitored continuously. Cardiac output was determined by periodic thermodilution. 3. Intracarotid injection of air produced an immediate drop in mean cerebral blood flow. This drop was transient and mean cerebral blood flow subsequently increased to 151% before declining slowly to baseline. Coincident with the increased cerebral blood flow was a sustained increase in mean cardiac output to 161% of baseline. Mean arterial blood pressure, heart rate and end-tidal carbon dioxide were not significantly altered by the intracarotid injection of air. 4. The increased cardiac output is a pathological response to impact of arterial air bubbles on the brain, possibly the brainstem. The increased cerebral blood flow is probably the result of the increased cardiac output and dilation of cerebral resistance vessels caused by the passage of air bubbles. [source] Attenuated endothelin-1 mRNA expression with endothelin-1 receptor blockade during hypoxaemia and reoxygenation in newborn pigletsACTA PAEDIATRICA, Issue 6 2000S Medbø We investigated the cause of decreased plasma endothelin-1 (ET-1) during hypoxaemia and reoxygenation in newborn piglets subjected to simultaneous blocking of the ET-1 receptors. Changes in plasma ET-1 and prepro-ET-1 mRNA expression in the main pulmonary artery and the left lower lobe in the lung were studied in 1-2-d-old piglets. Ten minutes prior to hypoxaemia, the hypoxaemia group (n = 10) was given saline, two groups (both n = 9) were given 1 and 5 mg/kg i.v. SB 217242 (an ET-1 receptor antagonist). Two groups served as normoxic controls, with and without SB 217242 5 mg/kg i.v. Hypoxaemia was induced by ventilating with 8% O2 until base excess was 20mmol/l or mean arterial blood pressure was < 20mmHg. Reoxygenation was performed for 2h with room air. During hypoxaemia, plasma ET-1 decreased in the hypoxaemia group, remained unchanged in the 1-mg group and increased in the 5-mg group. At the end of reoxygenation, plasma ET-1 was above baseline in the 1-mg and 5-mg groups. In the pulmonary artery, the hypoxaemia group showed 2- to 5-fold higher prepro-ET-1 mRNA expression compared to all the other groups (p < 0.05). There were trends for higher prepro-ET-1 mRNA expression in pulmonary tissue in the hypoxaemia group compared to the two receptor-blocking groups (p < 0.07). Conclusions: We conclude that hypoxaemia and reoxygenation increase prepro-ET-1 mRNA expression in the pulmonary artery in newborn piglets. These observations suggest that the half-life of ET-1 is decreased during hypoxaemia and reoxygenation in newborn piglets. [source] Stroke volume decreases during mild dynamic and static exercise in supine humansACTA PHYSIOLOGICA, Issue 2 2009M. Elstad Abstract Aim:, The contributions of cardiac output (CO) and total peripheral resistance to changes in arterial blood pressure are debated and differ between dynamic and static exercise. We studied the role stroke volume (SV) has in mild supine exercise. Methods:, We investigated 10 healthy, supine volunteers by continuous measurement of heart rate (HR), mean arterial blood pressure, SV (ultrasound Doppler) and femoral beat volume (ultrasound Doppler) during both dynamic mild leg exercise and static forearm exercise. This made it possible to study CO, femoral flow (FF) and both total and femoral peripheral resistance beat-by-beat. Results:, During a countdown period immediately prior to exercise, HR and mean arterial pressure increased, while SV decreased. During mild supine exercise, SV decreased by 5,8%, and most of this was explained by increased mean arterial pressure. Dynamic leg exercise doubled femoral beat volume, while static hand grip decreased femoral beat volume by 18%. FF is tightly regulated according to metabolic demand during both dynamic leg exercise and static forearm exercise. Conclusion:, Our three major findings are, firstly, that SV decreases during both dynamic and static mild supine exercise due to an increase in mean arterial pressure. Secondly, femoral beat volume decreases during static hand grip, but FF is unchanged due to the increase in HR. Finally, anticipatory responses to exercise are apparent prior to both dynamic and static exercise. SV changes contribute to CO changes and should be included in studies of central haemodynamics during exercise. [source] Studies of associations between the Arg389Gly polymorphism of the ,1 -adrenergic receptor gene (ADRB1) and hypertension and obesity in 7677 Danish white subjectsDIABETIC MEDICINE, Issue 4 2007A. P. Gjesing Abstract Aims, Activation of the ,1 -adrenergic receptor (ADRB1) causes increased lipolysis in adipose tissue and enhances cardiac output. Analysis of the association of the functional ADRB1 Arg389Gly variant with obesity and hypertension has given ambiguous results. To clarify the potential impact of this variant on obesity and hypertension in the general population, we examined the Arg389Gly variant in a relatively large-scale population-based study. Methods, Case-control studies and quantitative trait analyses were carried out in 7677 Danish Caucasians who were genotyped for the Arg389Gly variant (dbSNP rs1801253) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Results, A weak association between the Gly allele of the Arg389Gly variant and obesity was observed when comparing cases (n = 1540) defined as body mass index (BMI) > 30 kg/m2 with control subjects (n = 6108) defined as BMI , 30 kg/m2 for both allele frequencies (P = 0.05) and genotype distribution (P = 0.05). Case-control studies (cases n = 2518; control n = 3981) examining the effect on hypertension showed no association with allele frequencies (P = 0.3) or genotype distribution (P = 0.5); however, in the quantitative trait analyses, individuals carrying the Gly allele had slightly but significantly lower diastolic (Arg/Arg = 81.9 mmHg vs. Gly-allele carriers = 81.5 mmHg) and systolic (Arg/Arg = 129.4 mmHg vs. Gly-allele carriers = 128.8 mmHg) blood pressure as well as a lower mean arterial blood pressure. Conclusion, Our results suggest that the Arg389Gly polymorphism does not have any clinically important impact on the pathogenesis of obesity in Danish white subjects. Furthermore, despite the observed minor influence on blood pressure, this variant is most likely not to be a major contributor to the development of hypertension. [source] Structure,activity relationships of isoeugenol-based chlorophenylpiperazine derivatives on serotonergic/adrenergic receptor, platelet aggregation, and lipid peroxidationDRUG DEVELOPMENT RESEARCH, Issue 5 2010Kuo-Ping Shen Abstract Three isoeugenol-based eugenosedin chlorphenylpiperazine derivatives, Eu-A, Eu-B, and Eu-C, were synthesized and tested for their serotonergic, adrenergic antagonist, antioxidant, and anti-aggregation activities. In radioligand binding assays, all three agents displayed significant binding affinities on ,1, ,2, ,1, 5-HT1B, and 5-HT2A receptors. In human platelet, they inhibited epinephrine and 5-HT-induced aggregation, and in human platelet with ,2 and 5-HT2A receptors they had a competitive binding effect. Eu-B and Eu-C were more potent than Eu-A. All compounds had antioxidant effects derived from aryloxypropanolamine. Eu- A, Eu-B, or Eu-C (1, 3, 5,mg/kg iv) given to normotensive Wistar rats produced a dose-dependent decrease in mean arterial blood pressure and heart rate and when injected into the cisternum, Eu-A, Eu-B, or Eu-C (0.3, 0.03,µmol) increased blood pressure within 15,min. Pretreatment with any of the three agents inhibited clonidine (38,pmol)-induced hypotension. In vitro experiments, Eu-A, Eu-B, or Eu-C (1, 10, and 100,µM) competitively antagonized norepinephrine-, clonidine-, and 5-HT (10,8,10,4,M)-induced vasocontraction in isolated rat aorta, and competitively antagonized isoproterenol (10,8,10,4,M)-induced positive inotropic effects in a concentration-dependent manner in the isolated rat left atrium. In isolated rabbit ear arteries sensitized with 16,mM K+, all three agents antagonized 5-nonyloxytryptamine- and 5-HT-induced vasocontractions. These findings show that Eu-A, Eu-B, and Eu-C possess functional ,1, ,2, ,1, 5-HT1B, and 5-HT2A receptor blocking activities. In conclusion, the changes in the position of chloride at phenylpiperazine influenced the serotonergic receptor, adrenoceptor antagonistic activities, but not anti-aggregation and antioxidant activities. Drug Dev Res 71:1,9, 2010. © 2010 Wiley-Liss, Inc. [source] Effects of intravenous lidocaine overdose on cardiac electrical activity and blood pressure in the horseEQUINE VETERINARY JOURNAL, Issue 5 2001G. A. MEYER Summary This study aimed to identify blood serum lidocaine concentrations in the horse which resulted in clinical signs of intoxication, and to document the effects of toxic levels on the cardiovascular and cardiopulmonary systems. Nineteen clinically normal mature horses of mixed breed, age and sex were observed. Lidocaine administration was initiated in each subject with an i.v. loading dose of 1.5 mg/kg bwt and followed by continuous infusion of 0.3 mg/kg bwt/min until clinical signs of intoxication were observed. Intoxication was defined as the development of skeletal muscle tremors. Prior to administration of lidocaine, blood samples for lidocaine analysis, heart rate, mean arterial blood pressure, systolic blood pressure, diastolic blood pressure, respiratory rate and electrocardiographic (ECG) data were collected. After recording baseline data, repeat data were collected at 5 min intervals until signs of intoxication were observed. The range of serum lidocaine concentrations at which the clinical signs of intoxication were observed was 1.85,4.53 ,g/ml (mean ± s.d. 3.24 ± 0.74 ,g/ml). Statistically significant changes in P wave duration, P-R interval, R-R interval and Q-T interval were observed in comparison to control values, as a result of lidocaine administration. These changes in ECG values did not fall outside published normal values and were not clinically significant. Heart rate, blood pressures and respiratory rates were unchanged from control values. This study establishes toxic serum lidocaine levels in the horse, and demonstrates that there were no clinically significant cardiovascular effects with serum lidocaine concentrations less than those required to produce signs of toxicity. [source] A sympathetic view of the sympathetic nervous system and human blood pressure regulationEXPERIMENTAL PHYSIOLOGY, Issue 6 2008Michael J. Joyner New ideas about the relative importance of the autonomic nervous system (and especially its sympathetic arm) in long-term blood pressure regulation are emerging. It is well known that mean arterial blood pressure is normally regulated in a fairly narrow range at rest and that blood pressure is also able to rise and fall ,appropriately' to meet the demands of various forms of mental, emotional and physical stress. By contrast, blood pressure varies widely when the autonomic nervous system is absent or when key mechanisms that govern it are destroyed. However, 24 h mean arterial pressure is still surprisingly normal under these conditions. Thus, the dominant idea has been that the kidney is the main long-term regulator of blood pressure and the autonomic nervous system is important in short-term regulation. However, this ,renocentric' scheme can be challenged by observations in humans showing that there is a high degree of individual variability in elements of the autonomic nervous system. Along these lines, the level of sympathetic outflow, the adrenergic responsiveness of blood vessels and individual haemodynamic patterns appear to exist in a complex, but appropriate, balance in normotension. Furthermore, evidence from animals and humans has now clearly shown that the sympathetic nervous system can play an important role in longer term blood pressure regulation in both normotension and hypertension. Finally, humans with high baseline sympathetic traffic might be at increased risk for hypertension if the ,balance' among factors deteriorates or is lost. In this context, the goal of this review is to encourage a comprehensive rethinking of the complexities related to long-term blood pressure regulation in humans and promote finer appreciation of physiological relationships among the autonomic nervous system, vascular function, ageing, metabolism and blood pressure. [source] Possible role of exogenous cAMP to improve vascular endothelial dysfunction in hypertensive ratsFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 6 2006Dhvanit I. Shah Abstract The study has been designed to investigate the effect of 8-Br-cAMP, an activator of protein kinase A, in hypertension-induced vascular endothelial dysfunction. Rats were uninephroctomized and desoxycortisone acetate (DOCA) (40 mg/kg, s.c.) was administered to rats to produce hypertension (mean arterial blood pressure > 140 mmHg). Vascular endothelial dysfunction was assessed using isolated aortic ring preparation, electron microscopy of thoracic aorta and serum concentration of nitrite/nitrate. The expression of mRNA for p22phox and eNOS was assessed by using reverse transcriptase-polymerase chain reaction. Serum thiobarbituric acid reactive substances concentration and aortic superoxide anion concentration were estimated to assess oxidative stress. 8-Br-cAMP (5 mg/kg, i.p.) or atorvastatin (30 mg/kg, p.o.) prevented hypertension-induced attenuation of acetylcholine-induced endothelium-dependent relaxation, impairment of vascular endothelial lining, decrease in expression of mRNA for endothelial nitric oxide synthase (eNOS), serum nitrite/nitrate concentration and increase in expression of mRNA for p22phox, superoxide anion and serum TBARS. The ameliorative effect of 8-Br-cAMP was prevented by N -nitro- l -arginine methyl ester (25 mg/kg, i.p.) and glibenclamide (30 mg/kg, i.p.). It may be concluded that 8-Br-cAMP may stimulate expression and activity of eNOS and suppress expression of p22phox subunit of NADPH oxidase to reduce oxidative stress and subsequently improve vascular endothelial dysfunction. [source] The effects of exercise during hemodialysis on adequacyHEMODIALYSIS INTERNATIONAL, Issue 1 2005C. Caner Pedalling during hemodialysis (HD) has been shown to increase solute clearance in a previous study. In the present study, we aimed to test whether an easy to perform exercise program, not requiring a special device, could yield similar outcomes. Fifteen HD patients with the mean age of 48.4 ± 3.8 years were enrolled into the study. Patients with significant access recirculation (>10%), moderate to severe coronary artery disease, moderate to severe heart failure, severe chronic obstructive lung disease, and history of lower extremity surgery during last three month period were excluded. All patients were studied on two consecutive HD sessions with identical prescriptions. At the first session, standard HD was applied without exercise, whereas in the second session lower extremity exercise of 30 minutes duration was added. Reduction rates and rebound for urea, creatinine, and potassium and Kt/V were calculated. Wilcoxon signed rank test was applied in analysis and p < 0.05 was accepted as significance level. All patients completed the study. When both sessions were compared, mean arterial blood pressure (97 ± 3 mmHg vs 120 ± 4 mmHg, p < 0.001) and heart rate (77 ± 1 beats/min vs 92 ± 3 beats/min, p < 0.001) were higher in the exercise group. On the other hand, urea reduction rates, rebound values of urea, creatinine, and potassium were similar in both groups. Conclusion:,In the study, we did not observe any changes in solute rebound and clearance with the exercise. Shorter duration of the exercise may be the explanation of failure to achieve desired outcomes. Increasing patients' tolerance and fitness levels by means of steadily increasing exercise programs may be of help. Additionally, mode of exercise may also be responsible for different outcomes. [source] Diverse Effect of Inflammatory Markers on Insulin Resistance and Insulin-Resistance Syndrome in the ElderlyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 3 2004Angela M. Abbatecola MD Objectives: To evaluate the potential association between different inflammatory markers and insulin resistance (IR), as well as insulin-resistance syndrome (IRS) in a large, population-based study of older, nondiabetic persons. Design: Cross-sectional study. Setting: Outpatient clinic in Greve in Chianti and Bagno a Ripoli (Italy). Participants: One thousand one hundred forty-six nondiabetic subjects ranging in age from 22 to 104. Measurements: Anthropometric measurements; plasma fasting levels of glucose, insulin, and cholesterol (total, high-density lipoprotein, low-density lipoprotein); homeostasis model assessment to estimate degree of insulin resistance; tumor necrosis factor , (TNF-,), interleukin 6 (IL-6), soluble IL-6 receptor (sIL-6R), interleukin receptor antagonist (IL-1ra), and C-reactive protein (CRP) plasma concentrations; diastolic, systolic, and mean arterial blood pressure; and echo-color-Doppler duplex scanning examination of carotid arteries. Results: Insulin resistance correlated with age (r=0.102; P<.001) and plasma levels of TNF-, (r=0.082; P=.007), IL-1ra (r=0.147; P<.001), IL-6 (r=0.133; P<.001), sIL-6R (r=,0.156; P<.001), and CRP (r=0.83; P<.001). Subjects in the upper tertile of IR degree were older and had higher serum levels of TNF-,, IL-1ra, and IL-6 and lower levels of sIL-6R than subjects in the lowest tertile. Independent of age, sex, body mass index, waist-to-hip ratio, triglycerides, drug intake, diastolic blood pressure, smoking habit, and carotid atherosclerotic plaques, higher IL-6 (t=2.987; P=.003) serum concentrations were associated with higher IR, whereas sIL-6R levels (t=,5.651; P<.001) were associated with lower IR. Furthermore, IL-1ra concentrations (t=2.448; P=.015) were associated with IRS, and higher sIL-6R plasma levels continued to correlate negatively with IRS. Conclusion: Different inflammatory markers are associated with a diverse effect on IR and IRS in elderly nondiabetic subjects. [source] Comparative study on the regulation of body fluids and mammary circulation at different stages of lactation in crossbred Holstein cattle feeding on different types of roughageJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 2 2000N. Chaiyabutr Summary The present study was carried out to evaluate the effect of prolonged feeding of urea-treated rice straw, compared with feeding of hay, on the regulation of body fluids, milk yield and mammary circulation at early lactation (30 days postpartum), mid-lactation (120 days postpartum) and late lactation (210 days postpartum) in crossbred Holstein Friesians. Sixteen first lactating crossbred Holstein Friesians (HF), consisting of eight animals of two breed types, 87.5%HF and 50%HF, were selected and each breed was randomly allocated into two groups. Each group, consisting of four animals from the same breed, was fed either 5% urea-treated rice straw or pangola hay (Digitaria decumbens) as the source of roughage in combination with a similar concentrate throughout the experiments. During the course of lactation there were no significant differences in body weight, heart rate, mean arterial blood pressure, plasma osmolality, plasma volume and blood volume among groups of 87.5%HF animals and 50%HF animals fed either hay or urea-treated rice straw. Water turnover rate, total body water space and total body water as a percentage of body weight of 50%HF animals were significantly higher than those of 87.5%HF animals fed either hay or urea-treated rice straw. The packed cell volume was significantly higher in all lactating periods of both groups of 50%HF animals in comparison with 87.5%HF animals. The ratio of DM intake to milk production for 87.5%HF animals fed either hay or urea-treated rice straw was significantly lower than that of 50%HF animals in early lactation. The udder blood flow and milk secretion of 87.5%HF were significantly higher in early lactation and markedly declined when lactation advanced in comparison with those of 50%HF animals fed either hay or urea-treated rice straw. The ratio of mammary blood flow to milk yield for all groups was in a similar range during early lactation although it significantly increased in mid- and late lactation for both groups of 87.5%HF animals. From these results it can be concluded that both 50%HF and 87.5%HF animals feeding on urea-treated rice straw as a roughage source do not show any undernutritional effects in comparison with those fed with hay during the course of lactation. The physiological response differences between breeds are that 87.5%HF animals, which have a genetic makeup closer to the exotic bos taurus breed and a high milk yield, show a poor adjustment to the tropical environment and poorer lactation persistency in comparison with 50%HF animals. [source] Cardiopulmonary effects of HI-6 treatment in soman intoxicationJOURNAL OF APPLIED TOXICOLOGY, Issue S1 2001A. Göransson-Nyberg Abstract The cardiopulmonary effects of HI-6, together with atropine and soman, were studied in the rat. HI-6 is an effective antidote in acute poisoning with the nerve agent soman. The therapeutic efficiency of HI-6 is still unclear and cannot be explained entirely by the HI-6 reactivating ability of acetylcholinesterase (AChE). Other non-cholinergic factors must be involved. One possible detoxifying process might be an effect of HI-6 on the blood flow to sensitive organs. The purpose of the present study was to investigate 1) whether soman per se induces changes in regional blood flow and 2) whether the blood flow to different organs is affected when HI-6 (50 mg kg,1 i.m.) and atropine (10 mg kg,1 i.m.) are given either before or immediately after soman intoxication (90 µg kg,1 s.c.). For regional blood flow determinations the microsphere method was used with male Wistar rats weighing 300,400 g. The rats were anaesthetised and breathed spontaneously during the experiment. Three different blood flow measurements were made in the same animal and concomitant physiological parameters such as mean arterial blood pressure and respiratory rate were recorded. The blood AChE activity was followed throughout the experiment. Our results show that when HI-6 is given after intoxication with soman, dramatic changes in blood flow occur with a significant decrease in both respiratory rate and blood AChE activity. If HI-6 is given prior to the intoxication, however, all rats are unaffected and none of the parameters measured are changed. Copyright © 2001 John Wiley & Sons, Ltd. [source] Effects of sevoflurane on cognitive deficit, motor function, and histopathology after cerebral ischemia in ratsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2009E. EBERSPÄCHER Background: The volatile anesthetic sevoflurane exhibits neuroprotective properties when assessed for motor function and histopathology after cerebral ischemia in rats. Damage of hippocampal neurons after ischemia relates to a number of cognitive deficits that are not revealed by testing animals for motor function. Therefore, the present study evaluates cognitive and behavioral function as well as hippocampal damage in rats subjected to cerebral ischemia under sevoflurane compared with fentanyl/nitrous oxide (N2O)/O2 anesthesia. Methods: Thirty-four rats were trained for 10 days using a hole-board test to detect changes in cognitive and behavioral function. Rats were randomly assigned to the following groups: (A) sham/fentanyl/N2O/O2 (n=7); (B) ischemia/fentanyl/N2O/O2 (n=10); (C) sham/2.0 vol% sevoflurane in O2/air (n=7); and (D) ischemia/2.0 vol% sevoflurane in O2/air (n=10). Cerebral ischemia was produced by unilateral common carotid artery occlusion combined with hemorrhagic hypotension (mean arterial blood pressure 40 mmHg for 45 min). Temperature, arterial blood gases, and pH were maintained constant. Cerebral blood flow was measured using laser-Doppler flowmetry. After surgery, cognitive and behavioral function was re-evaluated for 10 days. On day 11, the brains were removed for histopathologic evaluation (hematoxylin/eosin-staining). Results: Cognitive testing revealed deficits in declarative and working memory in ischemic rats anesthetized with fentanyl/N2O. Rats anesthetized with sevoflurane during ischemia showed a significantly better outcome. Hippocampal damage was significantly worse with fentanyl/N2O. Conclusion: The present data add to previous investigations showing that sevoflurane prevents a deficit in cognitive function and histopathological damage induced by cerebral ischemia in rats. [source] Management of blood pressure after acute ischemic stroke: An evidence-based guide for the hospitalistJOURNAL OF HOSPITAL MEDICINE, Issue 4 2007Ethan Cumbler MD Abstract Hospitalists are frequently called upon to manage blood pressure after acute ischemic stroke. A review of both post infarction cerebral perfusion physiology and the data from randomized trials of antihypertensive therapy is necessary to explain why consensus guidelines for blood pressure management after stroke differ from those of other hypertensive emergencies. The peri-infarct penumbra is the central concept in understanding post ischemic cerebral perfusion. This area of impaired cerebral blood flow is dependent on mean arterial blood pressure and acute reduction of blood pressure may expand the area of infarction. Review of clinical trials fails to show benefit from reduction of blood pressure after ischemic stroke and current guidelines suggest antihypertensive therapy be employed if the systemic blood pressure is greater than 180/105 mmHg after tPA is employed, or 220/120 mmHg when tPA is not used. Induced hypertension remains a promising but unproven therapy in the acute setting, but the evidence for long term control of blood pressure to less than 140/80 mmHG for secondary prevention of stroke is strong. Adherence to guidelines is poor but it is recognized that current evidence is limited by a lack of trials in which blood pressure is titrated to a pre-specified goal, as is common in clinical practice. Journal of Hospital Medicine 2007;2:261,267. © 2007 Society of Hospital Medicine. [source] Comparison of closed loop vs. manual administration of propofol using the Bispectral index in cardiac surgeryACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2009J. AGARWAL Background: In recent years, electroencephalographic indices of anaesthetic depth have facilitated automated anaesthesia delivery systems. Such closed-loop control of anaesthesia has been described in various surgical settings in ASA I,II patients (1,4), but not in open heart surgery characterized by haemodynamic instability and higher risk of intra-operative awareness. Therefore, a newly developed closed-loop anaesthesia delivery system (CLADS) to regulate propofol infusion by the Bispectral index (BIS) was compared with manual control during open heart surgery. Methods: Forty-four adult ASA II,III patients undergoing elective cardiac surgery under cardiopulmonary bypass were enrolled. The study participants were randomized to two groups: the CLADS group received propofol delivered by the CLADS, while in the manual group, propofol delivery was adjusted manually. The depth of anaesthesia was titrated to a target BIS of 50 in both the groups. Results: During induction, the CLADS group required lower doses of propofol (P<0.001), resulting in lesser overshoots of BIS (P<0.001) and mean arterial blood pressure (P=0.004). Subsequently, BIS was maintained within ± 10 of the target for a significantly longer time in the CLADS group (P=0.01). The parameters of performance assessment, median absolute performance error (P=0.01), wobble (P=0.04) and divergence (P<0.001), were all significantly better in the CLADS group. Haemodynamic stability was better in the CLADS group and the requirement of phenylephrine in the pre-cardiopulmonary bypass period as well as the cumulative dose of phenylephrine used were significantly higher in the manual group. Conclusion: The automated delivery of propofol using CLADS was safe, efficient and performed better than manual administration in open heart surgery. [source] Effects of EP1 receptor on cerebral blood flow in the middle cerebral artery occlusion model of stroke in miceJOURNAL OF NEUROSCIENCE RESEARCH, Issue 11 2007Sofiyan Saleem Abstract The lipid mediator prostaglandin E2 (PGE2) exhibits diverse biologic activity in a variety of tissues. Four PGE2 receptor subtypes (EP1,4) are involved in various physiologic and pathophysiologic conditions, but differ in tissue distribution, ligand-binding affinity, and coupling to intracellular signaling pathways. To characterize the role of the EP1 receptor, physiologic parameters (mean arterial blood pressure, pH, blood gases PaO2 and PaCO2, and body temperature), cerebral blood flow (CBF), and neuronal cell death were studied in a middle cerebral artery occlusion model of ischemic stroke in wild-type (WT) and EP1 knockout (EP1,/,) mice. The right middle cerebral artery was occluded for 60 min, and absolute CBF was measured by [14C] iodoantipyrine autoradiography. The effect of EP1 receptor on oxidative stress in neuronal cultures was investigated. Although no differences were observed in the physiologic parameters, CBF was significantly (P < 0.01) higher in EP1,/, mice than in WT mice, suggesting a role for this receptor in physiologic and pathophysiologic control of vascular tone. Similarly, neuronal cultures derived from EP1,/, mice were more resistant (90.6 ± 5.8% viability) to tert -butyl hydroperoxide-induced oxidative stress than neurons from WT mice (39.6 ± 17.2% viability). The EP1 receptor antagonist SC-51089 and calcium channel blocker verapamil each attenuated the neuronal cell death induced by PGE2. Thus, the prostanoid EP1 receptor plays a significant role in regulating CBF and neuronal cell death. These findings suggest that pharmacologic modulation of the EP1 receptor might be a means to improve CBF and neuronal survival during ischemic stroke. © 2007 Wiley-Liss, Inc. [source] Oral melatonin reduces blood coagulation activity: a placebo-controlled study in healthy young menJOURNAL OF PINEAL RESEARCH, Issue 2 2008Petra H. Wirtz Abstract:, Melatonin has previously been suggested to affect hemostatic function but studies on the issue are scant. We hypothesized that, in humans, oral administration of melatonin is associated with decreased plasma levels of procoagulant hemostatic measures compared with placebo medication and that plasma melatonin concentration shows an inverse association with procoagulant measures. Forty-six healthy men (mean age 25 ± 4 yr) were randomized, single-blinded, to either 3 mg of oral melatonin (n = 25) or placebo medication (n = 21). One hour thereafter, levels of melatonin, fibrinogen, and D-dimer as well as activities of coagulation factor VII (FVII:C) and VIII (FVIII:C) were measured in plasma. Multivariate analysis of covariance and regression analysis controlled for age, body mass index, mean arterial blood pressure, heart rate, and norepinephrine plasma level. Subjects on melatonin had significantly lower mean levels of FVIII:C (81%, 95% CI 71,92 versus 103%, 95% CI 90,119; P = 0.018) and of fibrinogen (1.92 g/L, 95% CI 1.76,2.08 versus 2.26 g/L, 95% CI 2.09,2.43; P = 0.007) than those on placebo explaining 14 and 17% of the respective variance. In all subjects, increased plasma melatonin concentration independently predicted lower levels of FVIII:C (P = 0.037) and fibrinogen (P = 0.022) explaining 9 and 11% of the respective variance. Melatonin medication and plasma concentration were not significantly associated with FVII:C and D-dimer levels. A single dose of oral melatonin was associated with lower plasma levels of procoagulant factors 60 min later. There might be a dose,response relationship between the plasma concentration of melatonin and coagulation activity. [source] Melatonin in the duodenal lumen is a potent stimulant of mucosal bicarbonate secretionJOURNAL OF PINEAL RESEARCH, Issue 4 2003Markus Sjöblom Abstract: Melatonin, originating from intestinal enterochromaffin cells, mediates vagal and sympathetic neural stimulation of the HCO secretion by the duodenal mucosa. This alkaline secretion is considered the first line of mucosal defense against hydrochloric acid discharged from the stomach. We have studied whether luminally applied melatonin stimulates the protective secretion and whether a melatonin pathway is involved in acid-induced stimulation of the secretion. Rats were anaesthetized (Inactin®) and a 12-mm segment of proximal duodenum with an intact blood supply was cannulated in situ. Mucosal HCO secretion (pH-stat) and the mean arterial blood pressure were continuously recorded. Luminal melatonin at a concentration of 1.0 ,m increased (P < 0.05) the secretion from 7.20 ± 1.35 to 13.20 ± 1.51 ,Eq/cm/hr. The MT2 selective antagonist luzindole (600 nmol/kg, i.v.) had no effect on basal HCO secretion, but inhibited (P < 0.05) secretion stimulated by luminal melatonin. Hexamethonium (10 mg/kg i.v. followed by continuous i.v. infusion at a rate of 10 mg/kg/hr), abolishes neurally mediated rises in secretion and also inhibited (P < 0.05) the stimulation by luminal melatonin. Exposure of the lumen to acid containing perfusate (pH 2.0) for 5 min increased (P < 0.05) the HCO secretion from 5.85 ± 0.82 to 12.35 ± 1.51 ,Eq/cm/hr, and luzindole significantly inhibited (P < 0.05) this rise in secretion. The study thus demonstrates that luminal melatonin is a potent stimulant of duodenal HCO secretion and, furthermore, strongly suggests melatonin as an important mediator of acid-induced secretion. [source] Brain damage following severe acute normovolemic hemodilution in combination with controlled hypotension in ratsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 10 2007Y. L. Ge Background and aim:, The reduced oxygen content and perfusion pressure during acute normovolemic hemodilution (ANH) and controlled hypotension (CH) raise concerns about hypoperfusion and ischemic injury to the brain. In this study on rats, we examined the brain damage following four different degrees of ANH combined with CH. Methods:, Forty rats were randomly assigned to receive a sham operation or CH and ANH [with a hematocrit (Hct) of 30, 25, 20 or 15%]. ANH was performed after baseline physiological parameters had been monitored for 20 min; 30 min later, CH was induced using sodium nitroprusside, and the mean arterial blood pressure was maintained at 50,60 mmHg for 1 h. Rats were killed 3.5 h after hemodilution. Ultrastructural alterations in the CA1 region of the rat hippocampus were observed, and serum concentrations of S100B and neuron-specific enolase (NSE) were measured before and after ANH. Results:, The serum S100B concentration increased significantly in the Hct 20% + CH and Hct 15% + CH groups. However, there were no significant differences in the serum levels of NSE between the groups. In the CA1 region of the rat hippocampus, marked ultrastructural alterations, such as mitochondrial denaturalization and nucleus distortion, were observed in the Hct 20% + CH and Hct 15% + CH groups. Conclusion:, Severe ANH (Hct , 20%) combined with CH may induce cerebral damage, as confirmed by marked ultrastructural alterations in the CA1 region of the rat hippocampus and significantly increased serum levels of S100B, and should be avoided. [source] Cardiovascular effects of desflurane following acute hemorrhage in dogsJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 1 2003Paulo S.P. Santos DVM Abstract Objective: To determine the cardiovascular effects of desflurane in dogs following acute hemorrhage. Design: Experimental study. Animals: Eight mix breed dogs. Interventions: Hemorrhage was induced by withdrawal of blood until mean arterial pressure (MAP) dropped to 60 mmHg in conscious dogs. Blood pressure was maintained at 60 mmHg for 1 hour by further removal or replacement of blood. Desflurane was delivered by facemask until endotracheal intubation could be performed and a desflurane expiratory end-tidal concentration of 10.5 V% was maintained. Measurements and main results: Systolic, diastolic, and mean arterial blood pressure (SAP, DAP and MAP), central venous pressure (CVP), cardiac output (CO), stroke volume (SV), cardiac index (CI), systemic vascular resistance (SVR), heart rate (HR), respiratory rate (RR), partial pressure of carbon dioxide in arterial blood (PaCO2), and arterial pH were recorded before and 60 minutes after hemorrhage, and 5, 15, 30, 45 and 60 minutes after intubation. Sixty minutes after hemorrhage, SAP, DAP, MAP, CVP, CO, CI, SV, PaCO2, and arterial pH decreased, and HR and RR increased when compared with baselines values. Immediately after intubation, MAP and arterial pH decreased, and PaCO2 increased. Fifteen minutes after intubation SAP, DAP, MAP, arterial pH, and SVR decreased. At 30 and 45 minutes, MAP and DAP remained decreased and PaCO2 increased, compared with values measured after hemorrhage. Arterial pH increased after 30 minutes of desflurane administration compared with values measured 5 minutes after intubation. Conclusions: Desflurane induced significant changes in blood pressure and arterial pH when administered to dogs following acute hemorrhage. [source] Haemodynamic changes during positive-pressure ventilation in childrenACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2005A. Kardos Background:, Positive-pressure ventilation may alter cardiac function. Our objective was to determine with the use of impedance cardiography (ICG) whether altering airway pressure modifies the central haemodynamics in mechanically ventilated children with no pulmonary pathology. Central venous saturation (ScvO2) was measured as an indicator of tissue perfusion. Methods:, Twelve children between 7 and 65 months of age, requiring mechanical ventilation as a consequence of a non-pulmonary disease, were enrolled in the study. All patients had a central venous line as a part of their routine management. Using pressure controlled ventilation (PCV) the baseline PEEP value of 5 cmH2O (Pb5) was increased to 10 cmH2O (Pi10) and then to 15 cmH2O (Pi15). After Pi15, PEEP was decreased to 10 (Pd10) and then to 5 cmH2O (Pd5). Each time period lasted 5 min heart rate (HR), mean arterial blood pressure (MABP), central venous pressure (CVP), end-tidal carbon dioxide (ETCO2), mean airway pressure (Paw), stroke volume index (SVI), cardiac index (CI) and central venous oxygen saturation (ScvO2) were recorded at the end of the five periods. Results:, The values of CI did not change when 10 and 15 cmH2O of PEEP were applied. Elevation of PEEP and thus Paw caused slight but not significant reductions in SVI and ScvO2 as compared to the baseline (Tb5). After reducing PEEP in Td5 we found statistically significant elevations of SVI and CI, as compared to Ti15 heart rate, ETCO2 and MABP remained unchanged. Conclusion:, We did not find significant haemodynamic changes following PEEP elevation in ventilated children, as measured using impedance cardiography. Reducing the value of PEEP to 5 cmH2O resulted in statistically significant SVI elevations. The values of ScvO2 remained unaffected. [source] Management of critically ill children with traumatic brain injuryPEDIATRIC ANESTHESIA, Issue 6 2008GILLES A. ORLIAGUET MD PhD Summary The management of critically ill children with traumatic brain injury (TBI) requires a precise assessment of the brain lesions but also of potentially associated extra-cranial injuries. Children with severe TBI should be treated in a pediatric trauma center, if possible. Initial assessment relies mainly upon clinical examination, trans-cranial Doppler ultrasonography and body CT scan. Neurosurgical operations are rarely necessary in these patients, except in the case of a compressive subdural or epidural hematoma. On the other hand, one of the major goals of resuscitation in these children is aimed at protecting against secondary brain insults (SBI). SBI are mainly because of systemic hypotension, hypoxia, hypercarbia, anemia and hyperglycemia. Cerebral perfusion pressure (CPP = mean arterial blood pressure , intracranial pressure: ICP) should be monitored and optimized as soon as possible, taking into account age-related differences in optimal CPP goals. Different general maneuvers must be applied in these patients early during their treatment (control of fever, avoidance of jugular venous outflow obstruction, maintenance of adequate arterial oxygenation, normocarbia, sedation,analgesia and normovolemia). In the case of increased ICP and/or decreased CPP, first-tier ICP-specific treatments may be implemented, including cerebrospinal fluid drainage, if possible, osmotic therapy and moderate hyperventilation. In the case of refractory intracranial hypertension, second-tier therapy (profound hyperventilation with PaCO2 < 35 mmHg, high-dose barbiturates, moderate hypothermia, decompressive craniectomy) may be introduced, after a new cerebral CT scan. [source] The reliability of endtidal CO2 in spontaneously breathing children during anaesthesia with Laryngeal Mask AirwayTM, low flow, sevoflurane and caudal epiduralPEDIATRIC ANESTHESIA, Issue 5 2002Per AASHEIM MD Background: Noninvasive devices for monitoring endtidal CO2 (PECO2) are in common use in paediatric anaesthesia. Questions have been raised concerning the reliability of these devices in spontaneous breathing children during surgery. Our anaesthetic technique for elective infraumbilical surgery consists of spontaneous breathing through a Laryngeal Mask Airway (LMATM), low fresh gas flow, sevoflurane and a caudal epidural. We wanted to compare PECO2 and arterial CO2 (PaCO2) during surgery. Methods: Twenty children, aged 1,6 years, scheduled for infraumbilical surgery, were studied and one arterial sample was taken 45 min after induction of anaesthesia. PECO2, inspiratory PCO2, oxygen saturation, heart rate, respiratory rate, mean arterial blood pressure and expiratory sevoflurane concentration were measured every 5 min. The respiratory and circulatory parameters were stable during surgery. Results: The mean PaCO2 , PECO2 difference was 0.15 (0.16) kPa [1.1 (1.2 mmHg)]. Conclusions: PECO2 is a good indicator of PaCO2 in our anaesthetic setting. [source] | |||||||||||||||||||||||||||||||