Effect Of Mean Arterial Pressure Research Articles

Brain Arteriovenous Malformation In Vitro Model for Transvenous Embolization Using 3D Printing and Real Patient Data.

Transvenous embolization has emerged as a novel technique for treating selected brain AVMs with high reported occlusion rates. However, it requires anatomic and technical skills to be successful and to ensure patient safety. Therefore, training and testing are essential for preparing clinicians to perform these procedures. Our aim was to develop and test a novel, patient-specific brain AVM in vitro model for transvenous embolization by using 3D printing technology. We developed a brain AVM in vitro model based on real patient data by using stereolithography resin 3D printing. We created a closed pulsed circuit with flow passing from the arterial side to the venous side, and we tested the effect of mean arterial pressure on retrograde nidal filling with contrast injections. Transvenous embolization simulations were conducted for each of the 12 identical models divided into 2 groups (2×6). This involved the use of an ethylene-vinyl alcohol liquid embolic agent injected through microcatheters either without or with a coil in the vein (groups 1 and 2, respectively). Retrograde contrast advance to nidus was directly related to lower mean arterial pressure. Transvenous embolization tests with a liquid embolic agent adequately reproduced the usual embolization plug and push technique. We found no differences between the 2 group conditions, and additional venous coil neither increased nidus penetration nor reduced injection time in the model (57.6 versus 61.2% nidus occlusion rate, respectively). We were able to develop and test a functional in vitro brain AVM model for transvenous embolization by using 3D printing to emulate its conditions and characteristics. Better contrast penetration was achieved with less mean arterial pressure, and no embolization advantage was found by adding coil to the vein in this model.

Interventions to Optimize Spinal Cord Perfusion in Patients With Acute Traumatic Spinal Cord Injury: An Updated Systematic Review.

Systematic review update. Interventions that aim to optimize spinal cord perfusion are thought to play an important role in minimizing secondary ischemic damage and improving outcomes in patients with acute traumatic spinal cord injuries (SCIs). However, exactly how to optimize spinal cord perfusion and enhance neurologic recovery remains controversial. We performed an update of a recent systematic review (Evaniew et al, J. Neurotrauma 2020) to evaluate the effects of Mean Arterial Pressure (MAP) support or Spinal Cord Perfusion Pressure (SCPP) support on neurological recovery and rates of adverse events among patients with acute traumatic SCI. We searched PubMed/MEDLINE, EMBASE and ClinicalTrials.gov for new published reports. Two reviewers independently screened articles, extracted data, and evaluated risk of bias. We implemented the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) approach to rate confidence in the quality of the evidence. From 569 potentially relevant new citations since 2019, we identified 9 new studies for inclusion, which were combined with 19 studies from a prior review to give a total of 28 studies. According to low or very low quality evidence, the effect of MAP support on neurological recovery is uncertain, and increased SCPP may be associated with improved neurological recovery. Both approaches may involve risks for specific adverse events, but the importance of these adverse events to patients remains unclear. Very low quality evidence failed to yield reliable guidance about particular monitoring techniques, perfusion ranges, pharmacological agents, or durations of treatment. This update provides an evidence base to support the development of a new clinical practice guideline for the hemodynamic management of patients with acute traumatic SCI. While avoidance of hypotension and maintenance of spinal cord perfusion are important principles in the management of an acute SCI, the literature does not provide high quality evidence in support of a particular protocol. Further prospective, controlled research studies with objective validated outcome assessments are required to examine interventions to optimize spinal cord perfusion in this setting.

Interventions to Optimize Spinal Cord Perfusion in Patients with Acute Traumatic Spinal Cord Injury: An Updated Systematic Review (P14-7.004)

<h3>Objective:</h3> To conduct a systematic review to evaluate the effects of Mean Arterial Pressure (MAP) or Spinal Cord Perfusion Pressure (SCPP) support on neurological recovery and rates of adverse events among patients with acute traumatic spinal cord injury (SCI). <h3>Background:</h3> Interventions that aim to optimize spinal cord perfusion are thought to play an important role in minimizing secondary ischemic damage and improving outcomes in patients with acute traumatic SCIs. However, exactly how to optimize spinal cord perfusion and enhance neurologic recovery remains controversial. <h3>Design/Methods:</h3> We searched PubMed/MEDLINE, EMBASE and ClinicalTrials.gov. Two reviewers independently screened articles, extracted data, and evaluated risk of bias. We implemented the GRADE approach to rate confidence in the quality of the evidence. <h3>Results:</h3> From 569 potentially relevant new citations since 2019, we identified 9 new studies for inclusion, which were combined with 19 studies from a prior review to give a total of 28 studies. According to low or very low quality evidence, the effect of MAP support on neurological recovery is uncertain, and increased SCPP may be associated with improved neurological recovery. Both approaches may involve risks for specific adverse events, but the severity of these events and their importance to patients remains unclear. Very low quality evidence failed to yield reliable guidance about particular monitoring techniques, perfusion ranges, pharmacological agents, or durations of treatment. <h3>Conclusions:</h3> This update provides an evidence base to support the development of a new clinical practice guideline for the hemodynamic management of patients with acute traumatic SCI. While avoidance of hypotension and maintenance of spinal cord perfusion are important principles in the management of an acute SCI, the literature does not provide high quality evidence in support of a particular protocol. Further prospective, controlled research studies with objective validated outcome assessments are required to examine interventions to optimize spinal cord perfusion in this setting. <b>Disclosure:</b> An immediate family member of Dr. Kahn has received personal compensation for serving as an employee of Essai. Dr. Tetreault has nothing to disclose.

Effects of Blood Pressure and Arterial Stiffness on Retinal Neurodegeneration: Cross-Sectional and Longitudinal Evidence From UK Biobank and Chinese Cohorts.

Hypertension might be a modifiable risk factor for neurodegeneration diseases. However, the associations between blood pressure (BP), arterial stiffness index and retinal neurodegeneration remain unclear. This study used cross-sectional data from the United Kingdom BioBank (UKB) and longitudinal data from the Chinese Ocular Imaging Project (COIP). The macular ganglion cell-inner plexiform layer thickness (mGCIPLT) and macular retinal nerve fiber layer thickness were measured using spectral domain optical coherence tomography imaging. Swept-source optical coherence tomography was performed to obtain the longitudinal trajectory of the mGCIPLT and peripapillary retinal nerve fiber layer thickness in the COIP cohort. Multivariable linear models were used to analyze the associations between BP and retinal measurements. In a cross-sectional analysis of 22 801 participants from UKB, thinner mGCIPLT was related to higher systolic BP (β: -0.103 [-0.146 to -0.061]; P<0.001), and higher diastolic BP (β: -0.191 [-0.265 to -0.117]; P<0.001), and was significantly associated with higher mean arterial pressure (β: -0.174 [-0.238 to -0.109]; P<0.001) and higher mean pulse pressure (β: -0.080 [-0.139 to -0.020]; P=009). In a longitudinal analysis of 2012 eligible COIP participants, higher levels of baseline systolic BP, diastolic BP, mean arterial pressure, and mean pulse pressure were associated with faster thinning in mGCIPLT and peripapillary retinal nerve fiber layer thickness (all P<0.001). The strongest association was the effect of mean arterial pressure on mGCIPLT (β: -0.118 [-0.175 to -0.061]; P<0.001). The results of the analysis of macular retinal nerve fiber layer thickness and peripapillary retinal nerve fiber layer thickness were consistent with those of mGCIPLT. BP levels were independently and consistently associated with various retinal neurodegenerative exacerbations.

The Effect of Mean Arterial Pressure on the Progression of Arterial Stiffness in Normotensive Subjects

Abstract Background To examine the effect of mean arterial pressure on the progression of arterial stiffness in normotensive subjects. Methods The subjects who completed 2 measurements of brachial–ankle pulse wave velocity (baPWV) and were normotensive at the first baPWV measurement, were enrolled during the second, third, fourth, and fifth follow-up of the Kailuan study. Multiple linear regression was used to analyze the effect of baseline mean arterial pressure and mean arterial pressure on arterial stiffness at the end of follow-up and its progression in normotensive subjects. Results Among the 11,697 subjects who met the inclusion criteria, the average age was (43.7 ± 12.2) years old with 6,284 males (53.7%). The average follow-up time was 3.7 years, and baseline baPWV value was (1,346.2 ± 239.9) cm/s. The follow-up baPWV value was (1,403.4 ± 273.5) cm/s, and the average baPWV progression was 57.2 cm/s. In multivariate linear regression analysis, after adjustment for age, glucose, serum lipid, and other factors, an increase of 1 mm Hg in baseline mean arterial pressure resulted in an increase of 8. 6 cm/s in baPWV at the end of follow-up and 3.7 cm/s in baPWV progression, respectively. An increase of 1 mm Hg in mean arterial pressure during follow-up period resulted in an increase of 5.2 cm/s at the end of follow-up and 2.9 cm/s in baPWV progression, respectively. Conclusions Mean arterial pressures at baseline and during follow-up are associated with the progression of arterial stiffness in normotensive subjects.

Blood Pressure and Glaucomatous Progression in a Large Clinical Population

To investigate the effect of systemic arterial blood pressure (BP) on rates of progressive structural damage over time in glaucoma. Retrospective cohort study. A total of 7501 eyes of 3976 subjects with glaucoma or suspected of glaucoma followed over time from the Duke Glaucoma Registry. Linear mixed models were used to investigate the effects of BP on the rates of retinal nerve fiber layer (RNFL) loss from spectral-domain OCT (SD-OCT) over time. Models were adjusted for intraocular pressure (IOP), gender, race, diagnosis, central corneal thickness (CCT), follow-up time, and baseline disease severity. Effect of mean arterial pressure (MAP), systolic arterial pressure (SAP), and diastolic arterial pressure (DAP) on rates of RNFL loss over time. A total of 157 291 BP visits, 45 408 IOP visits, and 30 238 SD-OCT visits were included. Mean rate of RNFL change was-0.70 μm/year (95% confidence interval,-0.72 to-0.67 μm/year). In univariable models, MAP, SAP, and DAP during follow-up were not significantly associated with rates of RNFL loss. However, when adjusted for mean IOP during follow-up, each 10 mmHg reduction in mean MAP (-0.06 μm/year; P= 0.007) and mean DAP (-0.08 μm/year; P < 0.001) but not SAP (-0.01 μm/year; P= 0.355) was associated with significantly faster rates of RNFL thickness change over time. The effect of the arterial pressure metrics remained significant after additional adjustment for baseline age, diagnosis, sex, race, follow-up time, disease severity, and corneal thickness. When adjusted for IOP, lower MAP and DAP during follow-up were significantly associated with faster rates of RNFL loss, suggesting that levels of systemic BP may be a significant factor in glaucoma progression.

Modeling the Steady-State Effects of Mean Arterial Pressure on the Kidneys.

Goal: We describe the relationship between mean arterial pressure (MAP) and glomerular filtration rate (GFR) since therapies affecting MAP can have large effects on kidney function. Methods: We developed a closed-loop, steady-state mechanistic model of the human kidney with a reduced parameter set estimated from measurements. Results: The model was first validated against literature models. Further, GFR was validated against intensive care patient data (root mean squared error (RMSE) 13.5 mL/min) and against hypertensive patients receiving sodium nitroprusside (SNP) (RMSE less than 5 mL/min). A sensitivity analysis of the model reinforced the fact that vascular resistance is inversely related to GFR and showed that changes to either vascular resistance or renal autoregulation cause a significant change in sodium concentration in the descending limb of Henle. Conclusions: This model can be used to determine the impact of MAP on GFR and overall kidney health. The modeling framework lends itself to personalization of the model to a specific human.

Carotid Artery Stiffness in Metabolic Syndrome: Sex Differences.

IntroductionThe effect of metabolic syndrome (MS) on carotid stiffness (CS) in the context of gender is under research.ObjectiveWe examined the relationship between the MS and CS in men (M) and women (W) and investigated if the impact of cardiovascular risk factors on CS is modulated by gender.Patients and MethodsThe study included 419 subjects (mean age 54.3 years): 215 (51%) with MS (109 W and 106 M) and 204 (49%) without MS (98 W and 106 M). Carotid intima-media thickness (IMT) and CS parameters (beta stiffness index (beta), Peterson’s elastic modulus (Ep), arterial compliance (AC) and one-point pulse wave velocity (PWV-beta)) were measured with the echo-tracking (eT) system.ResultsANCOVA demonstrated that MS was associated with elevated CS indices (p = 0.003 for beta and 0.025 for PWV-beta), although further sex-specific analysis revealed that this relationship was significant only in W (p = 0.021 for beta). Age was associated with CS in both M and W, pulse pressure (PP) and body mass index turned out to be determinants of CS solely in W, while the effect of mean arterial pressure (MAP) and heart rate was more pronounced in M. MANOVA performed in subjects with MS revealed that age and diabetes mellitus type 2 were determinants of CS in both sexes, diastolic blood pressure and MAP – solely in M and systolic blood pressure, PP and waist circumference – solely in W (the relationship between the waist circumference and AC was paradoxical).ConclusionThe relationship between MS and CS is stronger in W than in M. In subjects with MS, various components of arterial pressure exert different sex-specific effects on CS – with the impact of the pulsative component of arterial pressure (PP) observed in W and the impact of the steady component (MAP) observed in M.

The influence of mean arterial blood pressure during cardiopulmonary bypass on post-operation acute kidney injury in hypertensive patients

Introduction: Over a period of time, kidney blood vessels will be damaged in those patients suffering from hypertension. Objectives: This study aimed to investigate the effect of mean arterial pressure during cardiopulmonary bypass (CBP). Patients and Methods: The present observational prospective study was conducted on 90 high risk patients, having records of hypertension and being candidates for open heart surgery. Patients divided into three groups based on their mean arterial pressure (MAP), lower than 60 mmHg (first group), between 60 to 70 mm Hg (second group) and higher than 70 mm Hg (third group) respectively during cardiopulmonary bypass. Clinical outcomes being studied included cardiac surgery-associated acute kidney injury (CSA-AKI) (RIFLE class), serum creatinine levels, glomerular filtration rate (GFR) and urinary output up to 24 hours after the surgery. Results: Data related to 90 case-patients have been analyzed. There was no difference between the groups in terms of demographic information. Prevalence of AKI in preliminary course after cardiac surgery was different among the groups. AKI occurred in six patients (15%) of the first group, five patients (12.5%) of the second group and two patients (5%) of the third group (P = 0.03). There have been no differences in terms of serum creatinine levels, GFR and urinary output during 24 hours after cardiac surgery, among the groups. However, delta creatinine level and delta GFR were significant in those groups with MAP of lower than 60 mm Hg and also between 60-70 mm Hg. Conclusion: This study showed that MAP level during CBP directly affects occurrence of AKI in patients after open heart surgery. High risk patients such as those suffering from hypertension have to be constantly monitored during CBP regarding their MAP. We concluded that MAP drops to lower than 70 mm Hg has to be prevented in hypertensive patients.

Mean Arterial Pressure Is Related to Incident Nonalcoholic Fatty Liver Disease among the Nonobese Female with Normal Low-Density Lipoprotein Cholesterol Levels: A Large Cohort Study in China

Aim We aimed to demonstrate the independent effect of mean arterial pressure (MAP) on incident nonalcoholic fatty liver disease (NAFLD) among the nonobese Chinese with normal low-density lipoprotein cholesterol (LDL-C) levels. Methods 16,153 nonobese participants without NAFLD at baseline were enrolled and then assigned to four groups by quartiles of MAP (Q1-Q4). A subgroup analysis by gender was also conducted. Participants were diagnosed with NAFLD by ultrasonography. Results During a mean follow-up of 2.80 years, the cumulative incidence of NAFLD was 14.37 and the incidence rate was 513.17 per 10,000 person-years. The cumulative incidence of NAFLD for the whole population or gender groups gradually increased with the quartiles of MAP (all P < 0.001). In the Q4 of MAP, the cumulative incidence of NAFLD for the whole population, male, and female reached up to 6.22 (5.75-6.70), 6.70 (6.21-7.19), and 5.69 (5.24-6.14), respectively. After adjustment for potential confounders, as compared with Q1, the hazard ratio for NAFLD was 1.328 (1.072-1.647), 1.625 (1.276-2.069), and 1.697 (1.231-2.340) for Q2, Q3, and Q4, respectively. In subgroup analysis, the respective hazard ratio for NAFLD in Q2, Q3, and Q4 of MAP was 1.760 (1.276-2.429), 2.080 (1.433-3.019), and 2.377 (1.452-3.890), compared with female in the Q1 of MAP. But MAP was not associated with incident NAFLD in male. Besides, MAP had a larger area under the receiver-operating characteristic curves than SBP or DBP, with optimal cutoff point of 88 mmHg in male and 89 mmHg in female. Conclusions MAP is an independent predictor for incident NAFLD among nonobese female with normal LDL levels.

Effect of mean arterial pressure on acute kidney injury in patients with septic shock

Objective To study the effect of mean arterial pressure (MAP) level on acute kidney injury (AKI) in patients with septic shock, and to determine the best resuscitation target MAP to prevent the occurrence or progression of sepsis- associated AKI. Methods The study subjects included 168 adult patients with septic shock (age≥65 years) who were admitted to the Department of Intensive Care Unit (ICU) of the First Hospital of Jilin University from January 2016 to January 2019. The clinical data of all enrolled patients were retrospectively analyzed. The baseline data were compared between the AKI group (n=111) and non-AKI group (n=57). Multivariate logistic regression analysis was used to determine the risk factors of AKI in patients with septic shock. Results ① The first, second, third, and forth quartile of ΔMAP (pre-resuscitation MAP minus post-resuscitation MAP) were -24.3-3.9 mmHg, 4.0-12.3 mmHg, 12.4-19.8 mmHg, and 19.9-43.5 mmHg, respectively. The second to fourth quartile interval wasΔMAP ≥4 mmHg.② There were no significant differences in age, body mass index, sex, pre-resuscitation MAP, MAP at first hour, SOFA score, positive culture ratio, negative culture ratio, hypertension, peripheral vascular disease, cerebrovascular accident, chronic obstructive pulmonary disease, gastrointestinal ulcer, liver cirrhosis, and tumor between the two groups (P>0.05). There were significant differences in post-resuscitation MAP (P=0.01), APACHEⅡ score (P=0.02), diabetes mellitus (P=0.01), fluid balance (P=0.01), and ΔMAP from the second to fourth quartile (P=0.03) between the two groups.③ ΔMAP ≥4 mmHg (OR=0.26, 95%CI: 0.12-0.57, P=0.01), diabetes (OR=6.03, 95%CI: 1.35-44.16, P=0.04), and high APACHE Ⅱ score (OR=0.96, 95%CI: 0.84-0.97, P=0.02) were closely related to the increased incidence of AKI in patients with septic shock. Post-resuscitation MAP and fluid balance had no significant effect on the incidence of AKI in patients with septic shock. Conclusions ΔMAP ≥4 mmHg, APACHE Ⅱ score and diabetes were independent risk factors for the incidence of AKI in patients with septic shock. The incidence of AKI in septic shock patients with post-resuscitation MAP 4 mmHg or more lower than pre-resuscitation MAP is significantly increased. Key words: Septic shock; Mean arterial pressure; Acute kidney injury; Risk factors

Abstract P2071: β-1,3/1,6-d-glucan Of Indonesian Ganoderma Lucidum Mycelium Extract Reduces Systolic Blood Pressure &amp; Inflammation In Hypertensive Patients

Background: Extract of Ganoderma lucidum Mycelium containing β-1,3/1,6-D-Glucan has shown to possess beneficial effects on cardiovascular diseases. Objective: To examine the effectiveness of β-1,3/1,6-D-Glucan (GLME) consumption to reduced blood pressure (BP) &amp; inflammation in patients with hypertension. Material and Methods: A randomized, double-blind, placebo-controlled clinical trial was conducted in 50 hypertensive adults (JNC VII, age 50-70 years). The patients were divided into 6 groups. Group A: received GLME 540mg/day + CCB, Group B: GLME + ACEI/ARB, Group C: placebo + ACEI, Group D: placebo + CCB, Group E: GLME only &amp; Group F: placebo only. We used the Morisky score to evaluate treatment’s adherence &amp; excludes patients with Morisky &lt; 6. A standardized method was used to measure BP at baseline and thereafter every 30 days until day 90. Further, heart rate (HR), LVEF, LVMI, hsCRP, MDA, TNF-α, IL-1, &amp; IL-6 were measured at baseline &amp; at 90-days. Results: At day 90, GLME lowered systolic BP (SBP) compared to placebo (–22.82±11.4 vs. –10±16.0 mmHg; p= 0.007), DBP was lowered without significant difference between GLME &amp; placebo groups. The change in mean arterial pressure was significance compared with placebo p= 0.028. Group B have the most reducing SBP effect compared with others, p=0.000. The reducing effect of mean arterial pressure was significance in group A compared with others, p= 0.008. In Group B, we found that there was a significance decreasing in hsCRP compared with p=0.01. The reducing effect LVMI, TNF-α, plasma IL- 6 and IL-1 concentration was significantly lower in group B compared with other group (p= 0.043, p= 0.001, p= 0.0008, p= 0.0005, respectively). Conclusion: GLME may significantly reduce SBP systolic &amp; LVMI &amp; may have an anti-inflammatory effect shown through the reduction of IL-6, IL-1β, and TNF-α.

Effects of mean arterial pressure on arousal in sedated ventilated patients with septic shock: a SEPSISPAM post hoc exploratory study

BackgroundIt is unknown whether the recommended mean arterial pressure (MAP) target of 65 mmHg during initial resuscitation of septic shock is sufficient to maintain cerebral perfusion. Thus, we tested the hypothesis that a higher MAP target in patients with septic shock may improve level of arousal.MethodsWe performed a post hoc exploratory analysis of the SEPSISPAM trial, which assessed the effect of a “high-target” level of MAP (80–85 mmHg) versus the recommended “low-target” MAP (65–70 mm Hg) on mortality in patients with septic shock. Among the 776 patients originally recruited in SEPSISPAM trial, we selected those who were mechanically ventilated and sedated and with available evaluation of arousal level assessed by the Richmond Agitation and Sedation Scale (RASS).ResultsWe restricted our analysis to the period in which patients were treated with vasoactive drugs. Cumulative sedative drugs were assessed daily. A total of 532 patients were included in this study: 253 (47.6%) in the low-target group and 279 (52.4%) in the high-target group. Daily cumulative sedative drugs were similar in both groups. Compared to the low-target group, minimal and maximal RASS were significantly higher in the high-target group at day 2, 4 and 5. Furthermore, in order to consider the fact that multiple measures were done for each patient and to consider the global effect of time on these measures, we used a mixed linear regression and multivariate models: we confirmed that maximal RASS values were significantly higher in the high-target group.ConclusionIn patients with septic shock who were mechanically ventilated and sedated, resuscitation with MAP target between 80 and 85 mmHg was associated with higher arousal level as compared to a MAP target between 65 and 70 mmHg.

A Retrospective Observational Study to Study the Effect of Mean Arterial Pressure on Renal Function During Cardiopulmonary Bypass

A Retrospective Observational Study to Study the Effect of Mean Arterial Pressure on Renal Function During Cardiopulmonary Bypass

Moderate Treadmill Exercise Training Improves Cardiovascular and Nitrergic Response and Resistance to Trypanosoma cruzi Infection in Mice.

There is evidence suggesting that exercise training (ET) acts as a factor toward resistance to Trypanosoma cruzi infection. However, the effects of mean arterial pressure (MAP), heart rate (HR), and nitric oxide (NO) during the acute phase of infection has not been elucidated yet. Swiss mice were randomly assigned into four groups: sedentary control (SC, n = 30), trained control (TC, n = 30), sedentary infected (SI, n = 30), and trained infected (TI, n = 30). ET was performed on the treadmill for 9 weeks. After training, the mice were infected with 5 × 103 trypomastigotes of T. cruzi (Y strain) or PBS. We observed resting bradycardia and improved performance in trained animals compared with sedentary ones. On the 20th day post-infection (DPI), we found a decrease in HR in SI animals compared to TI animals (699.73 ± 42.37 vs. 742.11 ± 25.35 bpm, respectively, P < 0.05). We also observed increased production of NO in cardiac tissue on the 20th DPI in the SI group, normalized in TI group (20.73 ± 2.74 vs. 6.51 ± 1.19 μM, respectively). Plasma pro-inflammatory cytokines (IL-12, TNF-α, IFN-γ,) and MCP-1 were increased in SI animals, but decreased in TI animals. The increase in parasitemia on the 15th and 17th DPI in the SI group was attenuated in the TI group. Our results suggest that previous ET plays a preventive role in resistance to T. cruzi infection, modulating cardiovascular aspects, inflammatory reaction, and NO levels of infected mice.

OP17 - Effects of mean arterial pressure on haematocrit during cardiopulmonary bypass - a substudy of the PPCI-trial

OP17 - Effects of mean arterial pressure on haematocrit during cardiopulmonary bypass - a substudy of the PPCI-trial

Effect of Intensive Blood Pressure Control on Cardiovascular Remodeling in Hypertensive Patients with Nephrosclerosis

Pulse pressure (PP), a marker of arterial system properties, has been linked to cardiovascular (CV) complications. We examined (a) association between unit changes of PP and (i) composite CV outcomes and (ii) development of left-ventricular hypertrophy (LVH) and (b) effect of mean arterial pressure (MAP) control on rate of change in PP. We studied 1094 nondiabetics with nephrosclerosis in the African American Study of Kidney Disease and Hypertension. Subjects were randomly assigned to usual MAP goal (102–107 mmHg) or a lower MAP goal (≤92 mmHg) and randomized to beta-blocker, angiotensin converting enzyme inhibitor, or calcium channel blocker. After covariate adjustment, a higher PP was associated with increased risk of CV outcome (RR = 1.28, CI = 1.11–1.47, P < 0.01) and new LVH (RR = 1.26, CI = 1.04–1.54, P = 0.02). PP increased at a greater rate in the usual than in lower MAP groups (slope ± SE: 1.08 ± 0.15 versus 0.42 ± 0.15 mmHg/year, P = 0.002), but not by the antihypertensive treatment assignment. Observations indicate that control to a lower MAP slows the progression of PP, a correlate of cardiovascular remodeling and complications, and may be beneficial to CV health.

The effect of mean arterial pressure during cardiopulmonary bypass on clinical and para clinical parameters during and after coronary artery bypass graft surgery

Isfahan University of Medical Sciences, Department of Anaesthesiology and Intensive Care, Isfahan, Iran, Islamic Republic of

Effect of mean arterial pressure, haemoglobin and blood transfusion during cardiopulmonary bypass on post-operative acute kidney injury

Acute kidney injury (AKI) after cardiac surgery is a common and serious condition carrying significant costs. During cardiopulmonary bypass (CPB) surgery, modifiable factors may contribute to post-operative AKI. Their avoidance might be a potential target for nephroprotection. The objective of the present study was to identify and determine whether intraoperative hypotension, anaemia, or their combination, red blood cell transfusion or vasopressor use are independent risk factors for post-operative AKI defined by the RIFLE (renal Risk, Injury, Failure, Loss of renal function and End-stage renal disease) classification and other thresholds using a mixed logistic multivariate model. We analysed 381 468 mean arterial pressure (MAP) measurements from 920 consecutive on-pump cardiac surgery patients. Overall, 19.5% developed AKI which was associated with an 8.2-fold increase in-hospital mortality. Haemoglobin concentration was an independent risk factor for AKI {odds ratio [OR] 1.16 per g/dL decrease [95% confidence interval (CI) 1.05-1.31]; P = 0.018} with systemic arterial oxygen saturation and pressure values not adding further strength to such an association. MAP alone or vasopressor administration was not independently associated with AKI but volume of red blood cell transfusion was, with its effect being apparent at a haemoglobin level of >8 g/dL (>5 mmol/L). In patients with severe anaemia (<25th percentile of lowest haemoglobin), the independent effect of hypotension (>75th percentile of area under the curve MAP <50 mmHg) on AKI was more pronounced [OR 3.36 (95% CI 1.34-8.41); P = 0.010]. Intraoperative avoidance of the extremes of anaemia, especially during severe hypotension and avoidance of transfusion in patients with haemoglobin levels >8 g/dL (>5 mmol/L) may help decrease AKI in patients undergoing cardiac surgery and represent targets for future controlled interventions.

Effects of Mean Arterial Pressure and Needle Size on Arterial Sampler Filling Time

Arterial blood sampling is subject to numerous pre-analytical errors, one of which is inadvertent venous blood sampling. Especially when assessing oxygenation and titrating ventilation, accidental venous blood sampling may lead to inappropriate respiratory care and repeated percutaneous punctures. To determine the effects of mean systemic blood pressure and needle size on vented arterial sampler filling times, to distinguish venous and arterial sampling. We constructed an extracorporeal laboratory model to circulate whole blood at 4 L/min. We used hemostats to create 6 pressures: 57 mm Hg (representing a patient in shock), 70 mm Hg (representing a patient with low-normal blood pressure), 93 mm Hg (normal), 107 mm Hg (high-normal), 133 mm Hg (severe hypertension), and 14 (peripheral venous pressure). We simulated percutaneous punctures with vented arterial samplers preset to 2 mL, with 2 common sampling needles. We compared the filling times of each pressure/needle combination and determined the correlation between the mean pressure and filling time. For all the tested arterial pressures combined, the mean ± SD sampler filling time was 15.8 ± 0.4 s; for venous pressures the time was 51.4 ± 1.4 s (P < .001). With the 22-gauge/1.5-inch needles the sampler filling time was 22.2 ± 14.9 s. With the 23-gauge/1-inch needle the time was 21.4 ± 13.1 s (difference not significant). The Pearson correlation coefficient between the mean blood pressures and the sampler filling times was r(2) = -0.86 (P = .01). Lower blood pressure increased the sampler filling time. Measuring the filling time may enable therapists to confirm successful arterial puncture in adult patients. Confirming successful arterial puncture prior to blood analysis would expedite appropriate patient care decisions.