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Objective Pulmonary hypertension is a characteristic feature of acute respiratory distress syndrome (ARDS) and contributes to mortality. Administration of sildenafil in ambulatory patients with pulmonary hypertension improves oxygenation and ameliorates pulmonary hypertension. Our aim was to determine whether sildenafil is beneficial for patients with ARDS. Design Prospective, open-label, multicenter, interventional cohort study. Setting Medical-surgical ICU of two university hospitals. Patients Ten consecutive patients meeting the NAECC criteria for ARDS. Interventions A single dose of 50 mg sildenafil citrate administered via a nasogastric tube. Main results Administration of sildenafil in patients with ARDS decreased mean pulmonary arterial pressure from 25 to 22 mmHg (P = 0.022) and pulmonary artery occlusion pressure from 16 to 13 mmHg (P = 0.049). Systemic mean arterial pressures were markedly decreased from 81 to 75 mmHg (P = 0.005). Sildenafil did not improve pulmonary arterial oxygen tension, but resulted in a further increase in the shunt fraction. Conclusion Although sildenafil reduced pulmonary arterial pressures during ARDS, the increased shunt fraction and decreased arterial oxygenation render it unsuitable for the treatment of patients with ARDS., Author(s): Alexander D. Cornet [sup.1], Jorrit J. Hofstra [sup.2] [sup.3], Eleonora L. Swart [sup.4], Armand R. J. Girbes [sup.1], Nicole P. Juffermans [sup.2] Author Affiliations: (1) grid.16872.3a, 000000040435165X, Department of [...]

The study aims to investigate whether therapy for reducing normal systolic pressure i.e.

The aim of this study was to examine the association between blood pressure (BP) in children and adolescents and cardiovascular and renal disease in adulthood. This was a retrospective study on patients, Author(s): Asthildur Erlingsdottir [sup.1] , Olafur S. Indridason [sup.2] , Olafur Thorvaldsson [sup.3] , Vidar O. Edvardsson [sup.1] [sup.4] Author Affiliations: (1) grid.14013.37, 0000000406400021, Faculty of Medicine, University of Iceland, [...]

The article reviews the use of thiazide diuretics, which are commonly indicated for long-term therapy for hypertension. It also examines the use of loop diuretics and potassium-sparing agents.

The study evaluates the long-term renoprotective effect of intensified blood-pressure control among children with chronic kidney disease receiving a fixed high dose of an angiotensin-converting-enzyme (ACE) inhibitor. Evidence indicates intensified blood-pressure control, with target 24-hour blood-pressure levels in the low range of normal, offers a significant benefit to renal function among children.

Dairy product intake could contribute to preventing hypertension, but information linking intake of these foods with changes in blood pressure over long periods of time, particularly in non-whites, is scarce. We analyzed the Atherosclerosis Risk in Communities study, a prospective cohort in the United States, to assess whether different types of dairy products were associated with changes in blood pressure over time. The analysis included 6912 white and 1296 African-American nonhypertensive men and women, aged 45-64 at baseline. After 9 years of follow-up, systolic blood pressure of whites consuming three or more daily servings of low-fat milk increased 2.7 mm Hg less than in those consuming less than one serving per week (P for trend = 0.01). Among African Americans, dairy products intake was not associated with changes in blood pressure over time. In conclusion, higher low-fat milk intake was associated with lower increases in blood pressure in whites but not in African Americans. doi:10.1038/ejcn.2009.50; published online 17 June 2009 Keywords: dairy; blood pressure; cohort; epidemiology; race, An elevated intake of dairy products has been repeatedly associated with reduced risk of high blood pressure (BP) (Pereira et al., 2002; Alonso et al., 2005; Wang et al., 2008; [...]

The sympathetic nervous system plays a key role in regulating arterial blood pressure in humans. This review provides an overview of sympathetic neural control of the circulation and discusses the [...]

Byline: Martin W. Dunser (1), Jukka Takala (1), Hanno Ulmer (2), Viktoria D. Mayr (3), Gunter Luckner (3), Stefan Jochberger (3), Fritz Daudel (1), Philipp Lepper (1), Walter R. Hasibeder (4), Stephan M. Jakob (1) Keywords: Hypotension; Mean arterial blood pressure; Mean perfusion pressure; Sepsis Abstract: Objective To evaluate the association between arterial blood pressure (ABP) during the first 24 h and mortality in sepsis. Design Retrospective cohort study. Setting Multidisciplinary intensive care unit (ICU). Patients and participants A total of 274 septic patients. Interventions None. Measurements and results Hemodynamic, and laboratory parameters were extracted from a PDMS database. The hourly time integral of ABP drops below clinically relevant systolic arterial pressure (SAP), mean arterial pressure (MAP), and mean perfusion pressure (MPP = MAP - central venous pressure) levels was calculated for the first 24 h after ICU admission and compared with 28-day-mortality. Binary and linear regression models (adjusted for SAPS II as a measure of disease severity), and a receiver operating characteristic (ROC) analysis were applied. The areas under the ROC curve were largest for the hourly time integrals of ABP drops below MAP 60 mmHg (0.779 vs. 0.764 for ABP drops below MAP 55 mmHg P a$? 0.01) and MPP 45 mmHg. No association between the hourly time integrals of ABP drops below certain SAP levels and mortality was detected. One or more episodes of MAP < 60 mmHg increased the risk of death by 2.96 (CI 95%, 1.06--10.36, P = 0.04). The area under the ROC curve to predict the need for renal replacement therapy was highest for the hourly time integral of ABP drops below MAP 75 mmHg. Conclusions A MAP level aY= 60 mmHg may be as safe as higher MAP levels during the first 24 h of ICU therapy in septic patients. A higher MAP may be required to maintain kidney function. Author Affiliation: (1) Department of Intensive Care Medicine, Inselspital, 3010, Bern, Switzerland (2) Institute of Medical Biostatistics, Innsbruck Medical University, Innsbruck, Austria (3) Department of Anesthesiology and Critical Care Medicine, Innsbruck Medical University, Innsbruck, Austria (4) Department of Anesthesiology and Critical Care Medicine, Krankenhaus Ried im Innkreis, Ried im Innkreis, Austria Article History: Registration Date: 22/01/2009 Received Date: 29/05/2008 Accepted Date: 19/01/2009 Online Date: 03/02/2009 Article note: Electronic supplementary material The online version of this article (doi: 10.1007/s00134-009-1427-2) contains supplementary material, which is available to authorized users.

Byline: B. L. Keulenaer (1), J. J. Waele (2), B. Powell (1), M. L. N. G. Malbrain (3) Keywords: Intra-abdominal hypertension; Abdominal compartment syndrome; Body positioning; Prone positioning; PEEP and ARDS Abstract: Purpose To describe what is defined as normal intra-abdominal pressure (IAP) and how body positioning, body mass index (BMI) and positive end-expiratory pressure (PEEP) affect IAP monitoring. Methods A review of different databases was made (Pubmed, MEDLINE (January 1966--June 2007) and EMBASE.com (January 1966--June 2007)) using the search terms of 'IAP', 'intra-abdominal hypertension' (IAH), 'abdominal compartment syndrome' (ACS), 'body positioning', 'prone positioning', 'PEEP' and 'acute respiratory distress syndrome' (ARDS). Prior to 1966, we selected older articles by looking at the reference lists displayed in the more recent papers. Results This review focuses on the concept that the abdomen truly behaves as a hydraulic system. The definitions of a normal IAP in the general patient population and morbidly obese patients are reviewed. Subsequently, factors that affect the accuracy of IAP monitoring, i.e., body position (head of bed elevation, lateral decubitus and prone position) and PEEP, are explored. Conclusion The abdomen behaves as a hydraulic system with a normal IAP of about 5--7 mmHg, and with higher baseline levels in morbidly obese patients of about 9--14 mmHg. Measuring IAP via the bladder in the supine position is still the accepted standard method, but in patients in the semi-recumbent position (head of the bed elevated to 30deg and 45deg), the IAP on average is 4 and 9 mmHg, respectively, higher. Future research should be focused on developing and validating predictive equations to correct for supine IAP towards the semi-recumbent position. Small increases in IAP in stable patients without IAH, turned prone, have no detrimental effects. The role of prone positioning in the unstable patient with or without IAH still needs to be established. Author Affiliation: (1) Intensive Care Unit, Fremantle Hospital, Alma Street, Fremantle, WA, 6160, Australia (2) Intensive Care Unit, Ghent University Hospital, Ghent, Belgium (3) Department of Intensive Care Medicine, Ziekenhuis Netwerk Antwerpen (ZNA), Stuivenberg, Antwerp, Belgium Article History: Registration Date: 10/02/2009 Received Date: 10/11/2008 Accepted Date: 06/02/2009 Online Date: 26/02/2009

BACKGROUND: Fine particulate matter [aerodynamic diameter [less than or equal to] 2.5 [micro]m ([PM.sub.2.5])] has been associated with autonomic dysregulation. OBJECTIVE: We hypothesized that [PM.sub.2.5] influences postural changes in systolic [...]

This study tested the hypothesis that passive heating impairs cerebral autoregulation. Transfer function analyses of resting arterial blood pressure and middle cerebral artery blood velocity (MCA [V.sub.mean]), as well as MCA [V.sub.mean] and blood pressure responses to rapid deflation of previously inflated thigh cuffs, were examined in nine healthy subjects under normothermic and passive heat stress (increase core temperature 1.1 [+ or -] 0.2[degrees]C, P < 0.001) conditions. Passive heating reduced MCA [V.sub.mean] [change ([DELTA]) of 8 [+ or -] 8 cm/s, P = 0.01], while blood pressure was maintained ([DELTA] - 1 [+ or -] 4 mmHg, P = 0.36). Coherence was decreased in the very-low-frequency range during heat stress (0.57 [+ or -] 0.13 to 0.26 [+ or -] 0.10, P = 0.001), but was >0.5 and similar between normothermia and heat stress in the low- (0.07-0.20 Hz, P = 0.40) and high-frequency (0.20-0.35 Hz, P = 0.12) ranges. Transfer gain was reduced during heat stress in the very-low-frequency (0.88 [+ or -] 0.38 to 0.59 [+ or -] 0.19 cm x [s.sup.-1] x [mmHg.sup.-1], P = 0.02) range, but was unaffected in the low-and high-frequency ranges. The magnitude of the decrease in blood pressure (normothermia: 20 [+ or -] 4 mmHg, heat stress: 19 [+ or -] 6 mmHg, P = 0.88) and MCA [V.sub.mean] (13 [+ or -] 4 to 12 [+ or -] 6 cm/s, P = 0.59) in response to cuff deflation was not affected by the thermal condition. Similarly, the rate of regulation of cerebrovascular conductance (CBVC) after cuff release (0.44 [+ or -] 0.22 to 0.38 [+ or -] 0.13 [DELTA]CBVC units/s, P = 0.16) and the time for MCA [V.sub.mean] to recover to precuff deflation baseline (10.0 [+ or -] 7.9 to 8.7 [+ or -] 4.9 s, P = 0.77) were not affected by heat stress. Counter to the proposed hypothesis, similar rate of regulation responses suggests that heat stress does not impair the ability to control cerebral perfusion after a rapid reduction in perfusion pressure, while reduced transfer function gain and coherence in the very-low-frequency range during heat stress suggest that dynamic cerebral autoregulation is improved during spontaneous oscillations in blood pressure within this frequency range. brain blood flow; heating; transfer function; blood pressure

Background. To examine the association between sleep-disordered breathing (SDB) and 24-hour blood pressure (BP) pattern among community-dwelling older adults. Methods. A convenience sample of 70 community-dwelling older adults, recruited from senior housing, community centers, and learning centers, were admitted to General Clinical Research Center, Emory University Hospital, Atlanta, Ga. Information regarding demographic and clinical history was obtained using questionnaires. Twenty-four-hour BP monitoring in supine position was performed using Spacelabs model 20207. Breathing during sleep was monitored with the use of a modified sleep recording system (Embletta, PDS), which monitors nasal and oral airflow, chest and abdominal movements, and pulse oximetry. Night time-daytime (night-day) BP ratio (average night-time BP divided by daytime BP) was calculated both for systolic and diastolic BPs. Results. Sixty-nine participants, mean age 74.9 [+ or -] 6.4 years (41 [57%] women), completed the study. The mean apnea-hypopnea index (AHI) was 13 [+ or -] 13 per hour of sleep, and 20 participants (29%) had AHI [greater than or equal to] 15 per hour of sleep, indicating moderate to severe SDB. Moderate to severe SDB (AHI [greater than or equal to] 15 per hour of sleep) was significantly associated with nocturnal hypertension, whereas there was no statistically significant difference in wake-time BP between those with and without moderate to severe SDB. Stepwise multiple regressions showed that AHI independently predicted increased night-day systolic and night-day diastolic BP ratio, even after controlling for nocturia frequency. Conclusions. The results indicate increased BP load associated with increased AHI in this group of older adults. This increased BP load may contribute to increased hypertension-related morbidity and disease burden. Key Words: Sleep-Disordered breathing--24-hour BP pattern.

Byline: Manuel Ignacio Monge Garcia (1), Anselmo Gil Cano (1), Juan Carlos Diaz Monrove (1) Keywords: Valsalva maneuver; Fluid responsiveness; Arterial pressure; Cardiac output; Cardiac preload; Spontaneous breathing Abstract: Objective To evaluate whether arterial pressure response during a Valsalva maneuver could predict fluid responsiveness in spontaneously breathing patients. Design and setting Prospective clinical study in a 17-bed multidisciplinary intensive care unit. Patients Thirty patients without mechanical ventilation and equipped with a radial arterial catheter for whom the decision to give fluids was taken due to suspected hypovolemia. Intervention A 10-s Valsalva maneuver was performed before and after volume expansion (VE). Patients were classified as responders if stroke volume index (SVi) increased aY=15% after VE. Measurements and results Pulse pressure changes during the Valsalva maneuver (aVPP) were calculated as the difference between maximal pulse pressure during phase 1 and minimal pulse pressure during phase 2 of the Valsalva maneuver divided by the mean of the two values and expressed as a percentage. Valsalva changes in systolic pressure (aVSP) were calculated in similar way. SVi changes induced by VE was correlated with baseline values of aVPP and aVSP (r .sup.2 = 0.71 and r .sup.2 = 0.60 P < 0.0001, respectively), and with VE-induced changes in aVPP and aVSP (r .sup.2 = 0.56 and r .sup.2 = 0.44 P < 0.0001 and P < 0.001, respectively). A aVPP value of 52% and aVSP of 30% predicted fluid responsiveness with a sensitivity of 91% and 73% and a specificity of 95 and 90%, respectively. Conclusions Arterial response during the Valsalva maneuver is a feasible tool for predicting fluid responsiveness in patients without mechanical ventilatory support. Author Affiliation: (1) Servicio de Cuidados Criticos y Urgencias, Unidad de Investigacion Experimental, Hospital del SAS Jerez, C/ Circunvalacion s/n, 11407, Jerez de la Frontera, Spain Article History: Registration Date: 03/09/2008 Received Date: 18/04/2008 Accepted Date: 29/08/2008 Online Date: 02/10/2008 Article note: This article is discussed in the editorial available at: doi: 10.1007/s00134-008-1294-2. Electronic supplementary material The online version of this article (doi: 10.1007/s00134-008-1295-1) contains supplementary material, which is available to authorized users.

Research on societal determinants of health suggests the existence of an 'inverse hazard law,' which we define as: 'The accumulation of health hazards tends to vary inversely with the power and resources of the populations affected.' Yet, little empirical research has systematically investigated this topic, including in relation to workplace exposures. We accordingly designed the United for Health study (Greater Boston Area, Massachusetts, 2003-2004) to investigate the joint distribution and health implications of workplace occupational hazards (dust, fumes, chemical, noise, ergonomic strain) and social hazards (racial discrimination, sexual harassment, workplace abuse). Focusing on blood pressure as our health outcome, we found that among the 1202 low-income multi-racial/ethnic working class participants in our cohort--of whom 40% lived below the US poverty line 79% reported exposure to at least one social hazard and 82% to at least one high- exposure occupational hazard. Only sexual harassment, the least common social hazard, was associated with elevated systolic blood pressure (SBP) among the women workers. By contrast, no statistically significant associations were detectable between the other additional highly prevalent social and occupational hazards and SBP; we did, however, find suggestive evidence of an association between SBP and response to unfair treatment, implying that in a context of high exposure, differential susceptibility to the exposure matters. These results interestingly contrast to our prior findings for this same cohort, in which we found associations between self-reported experiences of racial discrimination and two other health outcomes: psychological distress and cigarette smoking. Likely explanations for these contrasting findings include: (a) the differential etiologic periods and pathways involving somatic health, mental health, and health behaviors, and (b) the high prevalence of adverse exposures, limiting the ability to detect significant associations. As clarified by the 'inverse hazard law,' to understand health inequities, research is needed that contrasts exposures and health status population-wide, not just among those most inequitably exposed. Keywords: Blood pressure Health inequities Occupational health Racial discrimination Sexual harassment Workplace abuse USA

Byline: John A. Myburgh (1), Alisa Higgins (2), Alina Jovanovska (1), Jeffrey Lipman (3), Naresh Ramakrishnan (4), John Santamaria (5) Keywords: Epinephrine; Norepinephrine; Adrenaline; Noradrenaline; Shock; Sepsis Abstract: Objective To determine whether there was a difference between epinephrine and norepinephrine in achieving a mean arterial pressure (MAP) goal in intensive care (ICU) patients. Design Prospective, double-blind, randomised-controlled trial. Setting Four Australian university-affiliated multidisciplinary ICUs. Patients and participants Patients who required vasopressors for any cause at randomisation. Patients with septic shock and acute circulatory failure were analysed separately. Interventions Blinded infusions of epinephrine or norepinephrine to achieve a MAP aY=70 mmHg for the duration of ICU admission. Measurements Primary outcome was achievement of MAP goal >24 h without vasopressors. Secondary outcomes were 28 and 90-day mortality. Two hundred and eighty patients were randomised to receive either epinephrine or norepinephrine. Median time to achieve the MAP goal was 35.1 h (interquartile range (IQR) 13.8--70.4 h) with epinephrine compared to 40.0 h (IQR 14.5--120 h) with norepinephrine (relative risk (RR) 0.88 95% confidence interval (CI) 0.69--1.12 P = 0.26). There was no difference in the time to achieve MAP goals in the subgroups of patients with severe sepsis (n = 158 RR 0.81 95% CI 0.59--1.12 P = 0.18) or those with acute circulatory failure (n = 192 RR 0.89 95% CI 0.62--1.27 P = 0.49) between epinephrine and norepinephrine. Epinephrine was associated with the development of significant but transient metabolic effects that prompted the withdrawal of 18/139 (12.9%) patients from the study by attending clinicians. There was no difference in 28 and 90-day mortality. Conclusions Despite the development of potential drug-related effects with epinephrine, there was no difference in the achievement of a MAP goal between epinephrine and norepinephrine in a heterogenous population of ICU patients. Author Affiliation: (1) Department of Intensive Care Medicine, The St George Hospital, Gray Street, Kogarah, Sydney, 2217, Australia (2) Australian and New Zealand Intensive Care Research Centre, Monash University, Melbourne, Australia (3) Department of Intensive Care Medicine, Royal Brisbane Hospital and University of Queensland, Brisbane, Australia (4) Intensive Therapy Unit, Royal North Shore Hospital, Sydney, Australia (5) Department of Intensive Care Medicine, St Vincent's Hospital, Melbourne, Australia Article History: Registration Date: 09/07/2008 Received Date: 01/01/2008 Accepted Date: 19/06/2008 Online Date: 25/07/2008 Article note: This study was presented at the Annual Congress of the European Society of Intensive Care Medicine in Berlin on October 10 2007. The presentation received the International Sepsis Forum prize for best abstract and paper. This study has been published in abstract form: Myburgh J.A., Higgins A., Jovanovska A., Lipman J., Ramakrishnan N., Santamaria J and the CAT Study Investigators. (2007). A comparison of epinephrine and norepinephrine on reversal of shock. Intensive Care Medicine 33 (Supplement 2): S197. Trial registration: The study was registered with Current Controlled Studies: ISRCTN number 92846592.

In this study, we examined the relationship between within-person blood pressure and cognitive functioning. We conducted an analysis on 36 community-dwelling elderly individuals (age range = 60-87 years). Participants measured their blood pressure and completed cognitive tasks (i.e., the Rey Auditory Verbal Learning Task, the Letter Series test, and the Number Comparison test) twice a day over 60 consecutive days. We observed a significant interaction between within-person change in blood pressure and average blood pressure for the Letter Series test. Individuals with high blood pressure tended to perform poorly, particularly on occasions when their blood pressure level was above their personal average. These results demonstrate that the relationship between blood pressure and cognition at the between-person level and the relationship within each individual should be further explored simultaneously. Key Words: Blood pressure--Cognition--Variability--Aging.

A study was conducted to monitor patients in the United Kingdom with Type 2 diabetes and blood pressure and determine whether tight blood pressure control reduced risks of microvascular and macrovascular disease. Results indicated that tight blood pressure control did help improve diabetes and quality of life if sustained for a long period.

The study examines if the low ankle brachial index (ABI) adequately predicts the risk of cardiovascular events and mortality independently of the Framingham risk score (FRS). Findings indicate that measurement of the ABI could improve the accuracy of cardiovascular prediction separately from the FRS.

It is well known that environmental stimulation is important for the proper development of sensory function. The vestibular system senses gravitational acceleration and then alters cardiovascular and motor functions through reflex path-ways. The development of vestibular-mediated cardiovascular and motor functions may depend on the gravitational environment present at birth and during subsequent growth. To examine this hypothesis, arterial pressure (AP) and renal sympathetic nerve activity (RSNA) were monitored during horizontal linear acceleration and performance in a motor coordination task in rats born and reared in 1-G or 2-G environments. Linear acceleration of [+ or -] 1 G increased AP and RSNA. These responses were attenuated in rats with a vestibular lesion, suggesting that the vestibular system mediated AP and RSNA responses. These responses were also attenuated in rats born in a 2-G environment. AP and RSNA responses were partially restored in these rats when the hypergravity load was removed, and the rats were maintained in a 1-G environment for 1 wk. The AP response to compressed air, which is mediated independently of the vestibular system, did not change in the 2-G environment. Motor coordination was also impaired in the 2-G environment and remained impaired even after 1 wk of unloading. These results indicate that hypergravity impaired both the vestibulo-cardiovascular reflex and motor coordination. The vestibulo-cardiovascular reflex was only impaired temporarily and partially recovered following 1 wk of unloading. In contrast, motor coordination did not return to normal in response to unloading. vestibular system; renal sympathetic nerve activity; arterial pressure; rotarod; linear acceleration

The brain renin-angiotensin system plays an important role in the regulation of arterial pressure in response to stress, in part due to activation of A[T.sub.1] receptors in the hypothalamic median preoptic nucleus (MnPO) by endogenous angiotensin II (ANG II). N-methyl-D-aspartate (NMDA) receptors are also involved in the angiotensinergic signaling pathway through the MnPO. We investigated whether A[T.sub.1] and NMDA receptors in the MnPO are responsible for variable hemodynamic response patterns to stress. Cocaine or startle with cold water evoked a pressor response in Sprague-Dawley rats due, in some rats [vascular responders (VR)], to a large increase in systemic vascular resistance (SVR) and, in other rats [mixed responders (MR)], to small increases in SVR and cardiac output (CO). Microinjection of the GABAA agonist muscimol into the MnPO to block synaptic transmission attenuated the cocaine-or stress-induced increase in SVR and the decrease in CO seen in VR without altering either response in MR. Likewise, administration of either an A[T.sub.1] receptor antagonist, losartan, or an NMDA receptor antagonist, MK-801, attenuated the increase in SVR and the decrease in CO in VR in response to either cocaine (losartan and MK-801) or startle with cold water (losartan) without altering either response in MR. We propose that the MnPO is responsible for greater SVR responses in VR and that A[T.sub.1] and NMDA receptors play an important role in greater SVR responses in VR. These data provide additional support for the critical role of the MnPO in cardiovascular responses to stress. A[T.sub.1] receptor; cocaine; anteroventral third ventricle region; systemic vascular resistance; cardiovascular response variability

Byline: Emmanuel E. Douzinas (1,2), Olga Livaditi (2), Ilias Andrianakis (2), Panagiotis Prigouris (3), Pantelis Paneris (3), Vassiliki Villiotou (4), Alex P. Betrosian (2) Keywords: Hemorrhagic shock; Hypoxemic resuscitation; Cytokines; Reactive oxygen species; Malondialdehyde; Glutathione Abstract: Objective We investigated whether hypoxemic resuscitation from hemorrhagic shock prevents the late circulatory instability and attenuates the oxidative and inflammatory responses associated with the standard strategy. Design and setting Prospective, randomized, controlled animal study in an experimental laboratory of a university intensive care unit. Subjects Thirty-one New Zealand white rabbits weighting 3.1--3.4a-kg Interventions Anesthetized animals were subjected to hemorrhagic shock by exsanguinations to a mean arterial pressure of 40a-mmHg for 60a-min. Resuscitation was performed by reinfusing the shed blood for 30a-min under normoxemia (PaO.sub.2 95--105a-mmHg, control group, na-=a-10) or hypoxemia (PaO.sub.2 35--40a-mmHg, hypox-res group, na-=a-10) Ringer's lactate was given from 30 to 60a-min to restore arterial pressure within baseline values. A sham group was assigned (na-=a-11). Animals were recorded for 120a-min postresuscitation and for further 360a-min to assess the early mortality rate. Measurements and results Hypoxemic resuscitation compared with normoxemic resuscitation from hemorrhagic shock was associated with (a) a better hemodynamic condition assessed by the gradual restoration of blood pressure, higher urinary output associated with less fluid infusion (b) lower reactive oxygen species production assessed by the reduced blood geometric mean fluorescence intensity, lower malondialdehyde, and higher ratio of reduced to total glutathione levels (c) attenuation in the plasma concentrations of IL-1[beta], TNF-[alpha], and IL-6 and (d) no difference in mortality rate. Conclusions Hypoxemic resuscitation from hemorrhagic shock is more efficient than normoxemic in restoring the blood pressure and in attenuating the excessive oxidative and inflammatory responses observed during normoxemic resuscitation. Author Affiliation: (1) Evgenidion Hospital, 20 Papadiamantopoulou St., 11528, Athens, Greece (2) 3rd Department of Critical Care, Medical School, University of Athens, Athens, Greece (3) 2nd Departmentof Surgery, Evangelismos Hospital, Athens, Greece (4) Departmentof Clinical Biochemistry, Metaxa Cancer Hospital, Piraeus, Greece Article History: Registration Date: 08/11/2007 Received Date: 03/08/2007 Accepted Date: 06/11/2007 Online Date: 01/12/2007

Background. White matter lesions (WMLs) may contribute to cognitive deficits in patients with mild cognitive impairment (MCI), but their pathogenesis is complex. Fluctuations of blood pressure (BP) over 24 hours and genetic predisposition to develop vascular damage have been implicated. Methods. In 63 MCI patients 65 years old or older, BP was measured both clinically and with ambulatory BP monitoring. Patients were classified in two groups: no/very mild (n = 34) and mild to severe (n = 29) WMLs, based on a visual scale on magnetic resonance (mean age 71.8 [+ or -] 4.7 vs 74.6 [+ or -] 5.1, and female gender 53% vs 66%, respectively). The volume of WMLs was measured by a semi-automatic method, separately for periventricular caps and rim, periventricular confluent, subcortical punctate, and subcortical confluent. Polymorphisms of cystatin C (CST3) and cholesterol 24-hydroxylase (CYP46) genes, putative risk factors for cerebrovascular disease, were determined. Results. The prevalence of cerebrovascular risk factors was similar in the two MCI groups of different WML severity, as well as clinic and ambulatory BP. In patients with mild to severe, but not in those with no/very mild WMLs, the volume of periventricular confluent WMLs increased with increasing daytime systolic BP (regression coefficient .47, 95% confidence interval [CI],. 13 to .71 vs .02, 95% CI, -.32 to .36, p = .003 for the difference between slopes). The volume of other WML subtypes was not associated with ambulatory BP. Participants carrying both CST3*B and CYP46*T alleles were overrepresented in the MCI group with mild to severe WMLs (43% vs 17%, p .03). Conclusions. BP and gene putative risk factors for cerebrovascular disease are differentially associated with WMLs in two MCI groups of different WML severity. WMLs might develop for the convergence of innate with acquired factors. Key Words: Blood pressure--White matter lesions--Mild cognitive impairment--Genotype--Cystatin c.

A study to differentiate the advancement of subclinical atherosclerotic disease in patients with type 2 diabetes is conducted. Results conclude that treatment of low-density lipoprotein (LDL) cholesterol and systolic blood pressure bettered alternate measures of cardiovascular disease.

The effect of insulin on blood pressure (BP) is debated, and an involvement of an activated renin-angiotensin aldosterone system (RAAS) has been suggested. We studied the effect of chronic insulin infusion on telemetry BP and assessed sympathetic activity and dependence of the RAAS. Female Sprague-Dawley rats received insulin (2 units/day, INS group, n = 12) or insulin combined with losartan (30 mg*[kg.sup.-1]*[day.sup.-1], INS+LOS group, n = 10), the angiotensin II receptor antagonist, for 6 wk. Losartan-treated (LOS group, n = 10) and untreated rats served as controls (n = 11). We used telemetry to measure BP and heart rate (HR), and acute ganglion blockade and air-jet stress to investigate possible control of BP by the sympathetic nervous system. In addition, we used myograph technique to study vascular function ex vivo. The INS and INS+LOS groups developed euglycemic hyperinsulinemia. Insulin did not affect BP but increased HR (27 beats/min on average). Ganglion blockade reduced mean arterial pressure (MAP) similarly in all groups. Air-jet stress did not increase sympathetic reactivity but rather revealed possible blunting of the stress response in hyperinsulinemia. Chronic losartan markedly reduced 24-h-MAP in the INS+LOS group (-38 [+ or -] 1 mmHg P < 0.001) compared with the LOS group (-18 [+ or -] 1 mmHg, P [less than or equal to] 0.05). While insulin did not affect vascular function per se, losartan improved endothelial function in the aorta of insulin-treated rats. Our results raise doubt regarding the role of hyperinsulinemia in hypertension. Moreover, we found no evidence that insulin affects sympathetic nervous system activity. However, chronic losartan treatment revealed an important interaction between insulin and RAAS in BP control. insulin/hyperinsulinemia; hypertension; air-jet stress

Author(s): Heidi Ledford When a prestigious medical journal challenged scientists to analyse data from a pivotal blood-pressure study in search of new findings, hundreds of researchers around the world rushed [...]

Objective: To determine the effects of increasing mean arterial pressure (MAP) on renal resistances assessed by Doppler ultrasonography in septic shock. Design and setting: Prospective, single-center, nonrandomized, open-label trial in the surgical intensive care unit in a university teaching hospital. Patients and participants: 11 patients with septic shock who required fluid resuscitation and norepinephrine to increase and maintain MAP at or above 65 mmHg. Interventions: Norepinephrine was titrated in 11 patients in septic shock during three consecutive not randomized periods of 2 h to achieve a MAP at successively 65, 75, and 85 mmHg. Measurements and results: At the end of each period hemodynamic parameters and renal function variables (urinary output, creatinine, clearance) were measured, and Doppler ultrasonography was performed on interlobar arteries to assess the renal resistive index. When increasing MAP from 65 to 75 mmHg, urinary output increased significantly from 76 [+ or -] 64 to 93 [+ or -] 68 ml/h and the resistive index significantly decreased from 0.75 [+ or -] 0.07 to 0.71 [+ or -] 0.06. No difference was found between 75 and 85 mmHg. Conclusions: Doppler ultrasonography and resistive index measurements may help determine in each patient the optimal MAP for renal blood flow and may be a relevant end-point to titrate the hemodynamic treatment in septic shock. Keywords Septic shock * Norepinephrine * Renal function * Renal resistive index * Doppler ultrasonography

The intake of (n-3) long-chain PUFA is associated with a decreased risk of fatal myocardial infarction. Whether this effect is attributable to the effects of docosahexaenoic acid [22:6(n-3) (DHA)] on vascular function, particularly at intakes

We investigated autonomic control of cardiovascular function in able-bodied (AB), paraplegic (PARA), and tetraplegic (TETRA) subjects in response to head-up tilt following spinal cord injury. We evaluated spectral power of blood pressure (BP), baroreflex sensitivity (BRS), baroreflex effectiveness index (BEI), occurrence of systolic blood pressure (SBP) ramps, baroreflex sequences, and cross-correlation of SBP with heart rate (HR) in low (0.04-0.15 Hz)- and high (0.15-0.4 Hz)-frequency regions. During tilt, AB and PARA effectively regulated BP and HR, but TETRA did not. The numbers of SBP ramps and percentages of heartbeats involved in SBP ramps and baroreflex sequences increased in AB, were unchanged in PARA, and declined in TETRA. BRS was lowest in PARA and declined with tilt in all groups. BEI was greatest in AB and declined with tilt in all groups. Low-frequency power of BP and the peak of the SBP/HR cross-correlation magnitude were greatest in AB, increased during tilt in AB, remained unchanged in PARA, and declined in TETRA. The peak cross-correlation magnitude in HF decreased with tilt in all groups. Our data indicate that spinal cord injury results in decreased stimulation of arterial baroreceptors and less engagement of feedback control as demonstrated by lower 1) spectral power of BP, 2) number (and percentages) of SBP ramps and barosequences, 3) cross-correlation magnitude of SBP/HR, 4) BEI, and 5) changes in delay between SBP/HR. Diminished vasomotion and impaired baroreflex regulation may be major contributors to decreased orthostatic tolerance following injury. orthostatic hypotension; baroreflex sensitivity; baroreflex effectiveness index; cross correlation; feedback

A randomized controlled trial is used to evaluate the efficacy of a comprehensive pharmacy care program to improve medication adherence and its associated effects on blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C). The results have shown that pharmacy care program led to increase in medication adherence, medication persistence and clinically meaningful reductions in BP, but the discontinuation of this program was associated with decreased medication adherence and persistence.

Abstract Diagnosis of hypertension is critically dependent on accurate blood pressure measurement. "Accurate" refers to carefully following the guidelines for blood pressure measurement laid out for children and adults to [...]

Feedback control of total peripheral resistance (TPR) by the arterial and cardiopulmonary baroreflex systems is an important mechanism for short-term blood pressure regulation. Existing methods for measuring this TPR baroreflex mechanism typically aim to quantify only the gain value of one baroreflex system as it operates in open-loop conditions. As a result, the normal, integrated functioning of the arterial and cardiopulmonary baroreflex control of TPR remains to be fully elucidated. To this end, the laboratory of Mukkamala et al. (Mukkamala R, Toska K, and Cohen RJ. Am J Physiol Heart Circ Physiol 284: H947-H959, 2003) previously proposed a potentially noninvasive technique for estimating the closed-loop (dimensionless) gain values of the arterial TPR baroreflex ([G.sub.A]) and the cardiopulmonary TPR baroreflex ([G.sub.C]) by mathematical analysis of the subtle, beat-to-beat fluctuations in arterial blood pressure, cardiac output, and stroke volume. Here, we review the technique with additional details and describe its experimental evaluation with respect to spontaneous hemodynamic variability measured from seven conscious dogs, before and after chronic arterial baroreceptor denervation. The technique was able to correctly predict the group-average changes in [G.sub.A] and [G.sub.C] that have previously been shown to occur following chronic arterial baroreceptor denervation. That is, reflex control by the arterial TPR baroreflex was virtually abolished ([G.sub.A] = -2.1 [+ or -] 0.6 to 0.3 [+ or -] 0.2; P < 0.05), while reflex control by the cardiopulmonary TPR baroreflex more than doubled ([G.sub.C] = -0.7 [+ or -] 0.4 to -1.8 [+ or -] 0.2; P < 0.05). With further successful experimental testing, the technique may ultimately be employed to advance the basic understanding of TPR baroreflex functioning in both humans and animals in health and disease. autonomic nervous system; blood pressure; cardiovascular modeling; hemodynamics; system identification

We have explored the possibility that renal sympathetic nerve activity (RSNA) and vasomotor sympathetic nerve activity are differentially regulated. We measured sympathetic nerve activity (SNA) to the kidney and the hind limb vasculature in seven conscious rabbits 6-8 days after the implantation of recording electrodes. Acute infusion of [N.sup.G]-nitro-L-arginine methyl ester (L-NAME) (6 mg x [kg.sup.-1] x [min.sup.-1] for 5 min) led to an increase in blood pressure (from 66 [+ or -] 1 to 82 [+ or -] 3 mmHg) and a decrease in heart rate (from 214 [+ or -] 15 to 160 [+ or -] 13 bpm). L-NAME administration caused a significantly greater decrease in RSNA than lumbar sympathetic nerve activity (LSNA) (to 68 [+ or -] 14% vs. 84 [+ or -] 4% of control values, respectively). Volume expansion (1.5 ml x [kg.sup.-1] x [min.sup.-1]) resulted in a significant decrease in RSNA to 66 [+ or -] 7% of control levels but no change in LSNA (127 [+ or -] 20%). There was no difference in the gain of the baroreflex curves between the LSNA and RSNA [maximum gain of -7.6 [+ or -] 0.4 normalized units (nu)/ mmHg for LSNA vs. -7.9 [+ or -] 0.75 nu/mmHg for RSNA]. A hypoxic stimulus (10% [O.sub.2] and 3% C[O.sub.2]) led to identical increases in both RSNA and LSNA (195 [+ or -] 40% and 158 [+ or -] 21% of control values, respectively). Our results indicate tailored differential control of RSNA and LSNA in response to acute stimuli. sympathetic activity; blood pressure

A critical question in hypertension research is: How is long-term blood pressure controlled? Excessive NaCl ingestion or NaCl retention by the kidneys and the consequent tendency toward plasma volume expansion lead to hypertension. Nevertheless, the precise mechanisms linking salt to high blood pressure are unresolved. The discovery of endogenous ouabain, an adrenocortical hormone, provided an important clue. Ouabain, a selective [Na.sup.+] pump inhibitor, has cardiotonic and vasotonic effects. Plasma endogenous ouabain levels are significantly elevated in [approximately equal to] 40% of patients with essential hypertension and in animals with several forms of salt-dependent hypertension. Also, prolonged ouabain administration induces hypertension in rodents. Mice with mutant [Na.sup.+] pumps or Na/Ca exchangers (NCX) and studies with a ouabain antagonist and an NCX blocker are revealing the missing molecular mechanisms. These data demonstrate that [[alpha].sub.2] [Na.sup.+] pumps and NCX1 participate in long-term regulation of vascular tone and blood pressure. Pharmacological agents or mutations in the [[alpha].sub.2] [Na.sup.+] pump that interfere with the action of ouabain on the pump, and reduced NCX1 expression or agents that block NCX all impede the development of salt-dependent or ouabain-induced hypertension. Conversely, nanomolar ouabain, reduced [[alpha].sub.2] [Na.sup.+] pump expression, and smooth muscle-specific overexpression of NCX1 all induce hypertension. Furthermore, ouabain and reduced [[alpha].sub.2] [Na.sup.+] pump expression increase myogenic tone in isolated mesenteric small arteries in vitro, thereby tying these effects directly to the elevation of blood pressure. Thus, endogenous ouabain, and vascular [[alpha].sub.2] [Na.sup.+] pumps and NCX1, are critical links between salt and hypertension. New pharmacological agents that act on these molecular links have potential in the clinical management of hypertension. ouabain; [Na.sup.+] pump; Na/Ca exchanger; [Ca.sup.2+]; myogenic tone

Cerebral blood flow (CBF) is maintained constant despite changes in systemic blood pressure (BP) through multiple mechanisms of auto-regulation such as vascular myogenic reactivity. Our aim was to determine myogenic characteristics of cannulated middle cerebral arteries (MCA) in male and female stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar-Kyoto rats (WKY) at 12 wk of age under pressurised no-flow conditions. MCA pressure-diameter relationships (20-200 mmHg) were constructed in active (with calcium) and passive (without calcium) conditions, and myogenic and mechanical properties were determined. Myogenic reactivity in WKY (P < 0.05) and SHRSP (P < 0.05) males was impaired compared with their female counterparts. Comparison of SHRSP with WKY in males revealed similar myogenic reactivity, but in females SHRSP exhibited augmented myogenic reactivity (P < 0.05). In both sexes, myogenic tone yielded at lower pressure in SHRSP compared with WKY vessels (120-140 vs. 140-180 mmHg). Stress-strain relationships and elastic moduli in WKY rats showed that vessels were stiffer in females than in males. Conversely, in SHRSP, male vessels were stiffer than female vessels. Comparison of strains in males indicated that stiffness was increased in SHRSP compared with WKY vessels, whereas the converse was observed in females. These findings demonstrate that MCA myogenic and distensibility characteristics exhibit significant sex- and strain-dependent differences. Inappropriate myogenic adaptation and augmented vascular stiffness, particularly in male SHRSP, are potential limiting factors in blood flow autoregulation and may increase the predisposition for stroke-related cerebrovascular events. blood flow; blood pressure; distensibility; elastic modulus; strokeprone spontaneously hypertensive rats; Wistar-Kyoto rats

A study to compare blood pressure and related cardiovascular risk factors among three Caboclo communities of Brazilian Amazon is presented. Results suggest that seasonal variation does not affect average blood pressure in men, but it does affect the women.