Lower Mean Arterial Blood Pressure Research Articles

Increased Oxygen Saturation Is Associated with Decreased Sympathetic Nervous System Activity in Individuals Given Bacteriotherapy at High Altitude

Exposure to low-oxygen conditions (hypoxia), as encountered at high altitudes and in some pathological conditions, results in the activation of various physiological stressors and acclimatization to hypoxia. Previous studies show that administration of a novel probiotic (SLAB51; O2BOOSTER; Hecto, Seoul, South Korea) improves oxygen saturation in severely hypoxemic COVID-19 patients and in healthy participants upon exposure to simulated and terrestrial hypobaric hypoxic. Whether SLAB51 impacts stress responses such as activation of the sympathetic nervous system during high-altitude exposure has not been evaluated. We hypothesized that SLAB51 treatment and the associated increase in oxygen saturation would reduce metrics of heart rate variability (HRV) at high altitude. Volunteers of Latino ancestry (n=17; eight women, nine men) were recruited and completed sea-level and high-altitude measurements (up to four days at the University of California White Mountain Barcroft Research Station, 12,470 ft / 3,801 m). Participants ingested either the SLAB51 probiotic or a placebo (randomized double-blind procedure) upon arrival and throughout their duration at altitude, and oxygen saturation (SpO2), electrocardiogram (EKG), mean arterial blood pressure (MABP), and heart rate (HR) measurements were collected during a fasted state each morning. We performed HRV analysis based on data from 10 minutes of resting EKG recordings, which included evaluations of low-frequency (LF) and high-frequency (HF) bands and their ratio (LF/HF) as an estimation of sympathetic activity. All values were compared between probiotic and placebo groups at high altitude (mean ± SEM). The two groups did not exhibit differences in LF/HF, MABP, and HR on any of the days spent at high altitude; however, during the first evening at high altitude when the treatment groups exhibited differences in SpO2 (separately reported), the probiotic group exhibited a non-significant trend of lower MABP relative to the placebo group (n = 5, 87.3 ± 2.5 and n = 4, 93.5 ± 3.5, respectively; p = 0.078). Additionally, higher SpO2 associated with lower MABP (R2 = 0.33) across all time points at high altitude in the probiotic group, but the opposite relationship was noted in the placebo group (R2 = 0.30). These data suggest potential differences in sympathetic nervous system activation in probiotic and placebo groups, a finding which warrants further investigation in a larger sample of individuals. SLAB51; O2BOOSTER; Hecto, Seoul, South Korea. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Comparative Analysis of the Hemodynamic Effects of Remimazolam and Propofol During General Anesthesia: A Retrospective Study.

Hypotension is common during anesthesia induction. However, minimal hemodynamic effects of remimazolam anesthesia have been reported. We hypothesized that remimazolam would have weaker hemodynamic effects than would propofol. To test this, we simultaneously evaluated the hemodynamics using the estimated continuous cardiac output (esCCO) system and heart rate variability (HRV) during anesthesia induction. This was a single-center, observational, retrospective study of patients undergoing dental surgery under general anesthesia between 2020 and 2022. Seventy patients were divided into two groups: remimazolam (R group; n=34) and propofol (P group; n=36). The information obtained from the anesthesia records, patient information, esCCO system parameters, and HRV were integrated and analyzed. The percentages of various parameters were set to 100% for the pre-induction phase as the baseline. The %MAP (noninvasive mean arterial blood pressure) decreased over a narrower range in the R compared to the P group (-17.8% (-26.3%, -11.9%) vs. -22.6% (-32.9%, -17.0%); P=0.039). The %HR (heart rate) increased significantly in the R group and decreased in the P group (+10.7% (+6.5%, +18.6%) vs. -6.5% (-14.5%, +8.4%); P<0.01). The %SVesCCO(stroke volume calculated using the esCCO system) decreased significantly in both groups, but the R group showed a smaller difference compared to the P group (- 5.1% (-7.7%, -2.1%) vs. -10.0% (-13.8%, -5.6%); P<0.01). The rates of change in %LF nu (normalized unit of low frequency) and %HF nu (normalized unit of high frequency) were lower for the R than for the P group, although the difference was not significant (+6.8% (-14.5%, 32.4%) vs. +9.2% (-7.2%, +59.7%), P=0.30; +7.9% (-51.0%, +66.9%) vs. +22.8% (-26.1%, +61.6%), P=0.57). Remimazolam demonstrated a lower MAP reduction rate than propofol. A compensatory increase in HR occurred with a decrease in stroke volume. However, the HR increase was not attributable to the autonomic nervous system.

Developing a Clinically Relevant Hemorrhagic Shock Model in Rats.

Over the recent decades, the development of animal models allowed us to better understand various pathologies and identify new treatments. Hemorrhagic shock, i.e., organ failure due to rapid loss of a large volume of blood, is associated with a highly complex pathophysiology involving several pathways. Numerous existing animal models of hemorrhagic shock strive to replicate what happens in humans, but these models have limits in terms of clinical relevance, reproducibility, or standardization. The aim of this study was to refine these models to develop a new model of hemorrhagic shock. Briefly, hemorrhagic shock was induced in male Wistar Han rats (11-13 weeks old) by a controlled exsanguination responsible for a drop in the mean arterial pressure. The next phase of 75 min was to maintain a low mean arterial blood pressure, between 32 mmHg and 38 mmHg, to trigger the pathophysiological pathways of hemorrhagic shock. The final phase of the protocol mimicked patient care with an administration of intravenous fluids, Ringer Lactate solution, to elevate the blood pressure. Lactate and behavioral scores were assessed 16 h after the protocol started, while hemodynamics parameters and plasmatic markers were evaluated 24 h after injury. Twenty-four hours post-hemorrhagic shock induction, the mean arterial and diastolic blood pressure were decreased in the hemorrhagic shock group (p< 0.05). Heart rate and systolic blood pressure remained unchanged. All organ damage markers were increased with the hemorrhagic shock (p < 0.05). The lactatemia and behavioral scores were increased compared to the sham group (p < 0.05). In conclusion, we demonstrated that the protocol described here is a relevant model of hemorrhagic shock that can be used in subsequent studies, particularly to evaluate the therapeutic potential of new molecules.

Risk factors of Fournier’s gangrene associated with mortality in Sunpasittiprasong Hospital

Objective: To determine the mortality rate in patients with Fournier’s gangrene (FG) in Sunpasittiprasong Hospital and to identify potential risk factors associated with mortality among patients of FG. Materials and Methods: This retrospective cohort study investigated patients diagnosed with FG in Sunpasittiprasong Hospital from 2016 to 2021. Data related to clinical presentation, demographics, comorbidities, etiology, laboratory investigation, and therapeutic intervention of the patients were recorded. Prognostic severity indexes were calculated. All factors were statistically analyzed using univariate and then multivariate analysis. Results: Of 62 patients, the mortality rate was 29% (18 of 62). The significant risk factors for death included patients with kidney disease, septic shock, respiratory failure, acute kidney injury, low mean arterial blood pressure (MAP), admission to ICU and prolonged ventilator used. Risk factors from the laboratory data included abnormal coagulogram, high serum creatinine, lactate, and low bicarbonate. Some prognostic scoring systems were able to predict prognosis and mortality. Multivariate analysis revealed that patients with kidney disease (p = 0.007) or respiratory failure at presentation (p = 0.020) were significantly associated with mortality. Conclusions: The significant risk factors associated with mortality among patients with FG were kidney disease or respiratory failure. Some prognostic scoring systems may be applied to Thai patients with FG to predict prognosis.

Infant Milk Formula with Large, Milk Phospholipid-coated Lipid Droplets Enriched in Dairy Lipids Affects Body Mass Index Trajectories and Blood Pressure at School Age: Follow-up of a Randomized Controlled Trial

BackgroundHuman milk comprises large fat globules enveloped by a native phospholipid membrane, whereas infant formulas contain small, protein-coated lipid droplets. Previous experimental studies indicated that mimicking the architecture of human milk lipid droplets in infant milk formula (IMF) alters lipid metabolism with lasting beneficial impact on later metabolic health. ObjectivesTo evaluate in a follow-up (FU) study of a randomized, controlled trial whether a Concept IMF with large, milk phospholipid-coated lipid droplets enriched with dairy lipids beneficially impacts long-term body mass index (BMI in kg/m2) trajectories and blood pressure at school age. MethodsFully formula-fed infants were randomly assigned to Concept IMF (n = 115) or Control IMF with conventional, small lipid droplets containing vegetable oils (n = 108) for the first 4 mo of age. A group of 88 breastfed infants served as a reference. During FU, anthropometrics were collected at 1, 3, 4, and 5 y of age, and blood pressure only at the last visit. ResultsCompared to Control, Concept group children had consistently lower mean BMI values during FU, with the most marked difference at 1 y of age (difference in means –0.71 kg/m2, 95% confidence interval (CI): –1.13, –0.29; P = 0.001); mean values were close to the breastfed group (P > 0.05). Contrary, the mean BMI values of the Control group were higher compared with the breastfed group during FU from 1 to 5 y of age (differences in means from 0.59 to 0.96 kg/m2, respectively; P < 0.02). At 5 y of age, the Concept group had a lower mean diastolic and arterial blood pressure compared with the Control group; –4.3mm Hg (95% CI: –7.3, –1.3; P = 0.005) and –3.7 mm Hg (95% CI: –6.5, –0.9; P = 0.01), respectively. ConclusionsEarly life feeding of an innovative IMF with large, milk phospholipid-coated lipid droplets enriched with dairy lipids results in a BMI trajectory closer to breastfed infants and a lower blood pressure at school age.This trial was registered at the Dutch Trial Register as NTR3683 and NTR5538.

Abstract 18474: Impact of the Endothelial Nucleotidase on Vascular Function

Introduction: Cardiovascular disease (CVD) is the leading cause of mortality and morbidity worldwide. Endothelial dysfunction—marked by poor endothelial-derived vasodilation—is a major prelude to atherosclerotic cardiovascular disease. Endothelial cells (EC) play a vital role in modulating thrombosis, atherosclerosis, and blood flow. One tool the endothelium uses to communicate with surrounding tissues is purinergic signaling. EC express both purinergic receptors to respond to stimuli and ectonucleotidases to facilitate this communication. CD39 is believed to be vital in maintaining homeostasis within the vasculature as it is an ectonucleotidase responsible for converting extracellular ATP and ADP into AMP. However, little is known about the role of endothelial expressed CD39 on vascular function. Hypothesis: We hypothesized that the absence of endothelial CD39 causes an elevation in extracellular adenine-nucleotides, thus causing an elevated endothelial-derived vasodilatory response. Methods: We generated a novel cre-lox endothelial cell-specific CD39 knockout mouse model ( Tie2cre+ CD39flox/flox ) to explore the enzyme’s role in vascular physiology. After validation via flow cytometry and enzyme activity assays, we assessed mouse blood pressure along with EC-derived vasodilatory capacity. Coronary vasodilatory capacity or coronary flow reserve (CFR) was measured via an isoflurane-induced-vasodilation coronary flow model and imaged using transthoracic ultrasound. Results: We noted that the EC specific CD39 knockout mice (EC-cKO) exhibited significantly lower systolic, diastolic, and mean arterial blood pressures at baseline, showing the EC-cKO mice having reduced pressures of over 10mmHg compared to wild-type (EC-WT) (p&lt;0.05). This suggested fundamental differences in vascular function, prompting assessment of CFR. The EC-cKO mice showed a 75.9% increase in CFR (p&lt;0.05) compared to wild-type (EC-WT). Conclusions: The loss of CD39 on EC leads to an overall protective phenotype—EC-cKO mice show drastically lower blood pressures, likely due to improved vasodilatory capacity under healthy conditions. This study shows CD39 inhibition’s potential as a therapeutic target in terms of improving vascular function.

Treatment effects of blood pressure targets and hemodynamics according to initial blood lactate levels in comatose out-of-hospital cardiac arrest patients – A sub study of the BOX trial

BackgroundOut-of-hospital cardiac arrest (OHCA) survivors remaining comatose are often circulatory unstable with high mortality in the first days following resuscitation. Elevated lactate will reflect the severity and duration of hypoperfusion in cardiac arrest. Further, the severity of hypoperfusion could modify the effect on survival of different mean arterial blood pressure (MAP) targets. MethodsIn this sub-study of the BOX trial, adult successfully resuscitated comatose OHCA patients (n = 789) with a presumed cardiac cause were randomized to a MAP target of 63 mmHg vs. 77 mmHg. Patients were arbitrarily grouped in low-lactate: <25% of sample, medium-lactate: 25%–75%, and high >75 percentile according to blood lactate levels at hospital arrival as a surrogate of the severity of hypoperfusion. Invasive hemodynamic evaluations were performed using an arterial catheter and pulmonary artery catheter (PAC), and data from admission to 48 hours (h) were recorded. Logistic regression analysis evaluated whether lactate levels (as continuous and categorical) modify the effect of MAP targets on mortality at 365 days. ResultsThe three lactate groups had initial lactate levels of low-lactate: <2.9 mmol/L, medium-lactate: 2.9–7.9 mmol/L, and high-lactate > 7.9 mmol/L. All patients were randomized to a 63 mmHg or 77 mmHg MAP target. The proportion of patients in the high-MAP target group was 100/201 (50%), 178/388 (46%), and 114/197 (58%) for low, medium, and high-lactate groups respectively. At admission, the high-lactate groups had a lower MAP compared to the medium-lactate (2.6 mmHg (95% CI: 0.1–5.0 mmHg, p = 0.02), and the low-lactate group, (3.6 mmHg (95% CI: 0.8–6.5 mmHg, p < 0.01). Accordingly, the vasoactive inotropic score was 79% (95%CI: 42%–124%%) higher with increasing initial lactate level (High-lactate vs. low-lactate) with the largest difference at 6 hours (110.6% (95%CI: 54.4%–187.2%) higher in high-lactate patients). No difference in the cardiac index or systemic vascular resistance was observed between lactate groups. The initial lactate level (continuous) modified the effect of the two MAP targets (p = 0.04). In the highest lactate group, the mortality was 100/197 (51%), and with an odds ratio (OR): 1.7 (95%CI: 0.9–3.0) if randomized to MAP 77 mmHg compared to MAP 63 mmHg. In the lowest lactate group, the mortality was 35/201(17%) and similar if randomized to a MAP target of 77 mmHg (OR: 1.1 (95% CI: 0.5–2.3)). ConclusionComatose OHCA patients with high initial lactate levels required more vasoactive drugs on the first two days of ICU admission to meet the blood pressure target and had a poorer prognosis. No indication that aiming for a higher MAP target is beneficial in patients with an initial high lactate level was found, however, given the post-hoc nature of this study, these results should be considered hypothesis-generating

The Effects of Remifentanil, Dexmedetomidine, and Metoral as Adjuncts to Thiopental on Hemodynamic Status After Electroconvulsive Therapy in Patients with Major Depressive Disorder: A Randomized Controlled Clinical Trial.

Depression is a prevalent mental disorder affecting more than 300 million people of all ages globally. Despite being the first-line treatment for depression, antidepressant medications are only effective for 60% - 70% of patients. Electroconvulsive therapy (ECT) is an effective treatment for severe cases, although it can result in short-term side effects. This study aimed to compare the effectiveness of remifentanil, dexmedetomidine, and metoral as premedications for ECT in patients with major depressive disorder (MDD). In this prospective double-blinded randomized controlled clinical trial, a total of 120 MDD patients aged 18 - 60 were included. They were randomly assigned to receive remifentanil, dexmedetomidine, or metoral in combination with thiopental before ECT. Hemodynamic responses (mean arterial blood pressure, pulse rate, arterial blood oxygen saturation), seizure duration, recovery time, agitation scores, and patient satisfaction scores (reverse coded) were measured and compared. Dexmedetomidine exhibited superior hemodynamic control with lower mean arterial blood pressure (P < 0.001) and pulse rate (P < 0.001) than remifentanil and metoral. Patients receiving dexmedetomidine or remifentanil showed reduced agitation (P < 0.001) and better satisfaction than the metoral group (P < 0.001). Remifentanil displayed intermediate outcomes, while metoral exhibited the least favorable results. Seizure duration was not significantly different between the dexmedetomidine and remifentanil groups (P = 0.843). Dexmedetomidine is considered the most satisfactory group due to the better control of blood pressure, heart rate, and agitation and better patient satisfaction despite the longer recovery time.

COMBINING RENIN-ANGIOTENSIN SYSTEM (RAS) BLOCKADE AND SODIUM-GLUCOSE COTRANSPORTER-2 (SGLT2) INHIBITION IN EXPERIMENTAL DIABETES RESULTS IN SYNERGISTIC BENEFICIAL EFFECTS

Objective: To study the combined effect of RAS blockade and SGLT2i in experimental diabetes. Design and method: TGR (mREN2)27 rats (a model of angiotensin II-dependent hypertension) were made diabetic with streptozotocin for 12 weeks and treated with either vehicle, the angiotensin receptor blocker valsartan (VAL: 4 mg/kg/day), the SGLT2 inhibitor empagliflozin (EMPA: 10 mg/kg/day) or their combination during the final 3 weeks. Mean arterial blood pressure (MAP) was measured by telemetry. Results: MAP before treatment was 120 ± 14 mm Hg. Diabetes resulted in albuminuria, accompanied by glomerulosclerosis, without a change in glomerular filtration rate (GFR). EMPA did not lower MAP, while VAL did (by 29 ± 7 mm Hg), and when combined the MAP drop was largest (44 ± 6 mm Hg). Only EMPA+VAL reduced the heart weight/tibia length ratio (P = 0.04 vs. vehicle). VAL, but not EMPA, increased plasma renin, and the largest renin rise was observed during EMPA+VAL (P &lt; 0.0001 vs. vehicle) Although both VAL and EMPA alone tended to diminish albuminuria, the reduction was significant (P = 0.01 vs. vehicle) only when both drugs were combined (vehicle, VAL, EMPA and EMPA+VAL 108 ± 18, 89 ± 24, 55 ± 8 and 26 ± 6 ug/mL, respectively). This was accompanied by a reduction in glomerulosclerosis index and no change in GFR. EMPA either alone or in combination with VAL increased water intake and urine production and induced urinary glucose loss, and as a consequence reduced blood glucose and body weight. Renal expression of the fibrosis and inflammatory markers TIMP2, collagen 1alpha 1, fibronectin, Neph1, nephrin was lowest in the dual treatment group. Conclusions: RAS blockade and SGLT2i display synergistic beneficial effects on blood pressure, kidney jury and cardiac hypertrophy in a rat with hypertension and diabetes.

Spontaneous Subgaleal Hemorrhage in a Child with Autism

Objective Women have continued to bear a heavy burden of cardiovascular disease morbidity and mortality with hypertension as the flagship. This is partly because as the modifiable cardiovascular disease risk factors are falling in rate, gender specific risk factors have persisted. One of them is age at first pregnancy and delivery. Methods In order to contribute to this discourse, we secondarily analysed data generated in a previous field study on risk factors for cardiovascular diseases in free living adults in Plateau State, Nigeria. The women were divided into four groups and we looked at blood pressure at the time of study from the perspective of age at first pregnancy. Reults It was found that those who had their first pregnancy in the late teenage years had the lowest mean arterial blood pressure many years down the line; better than those who started child bearing earlier and those who started later. There was also significant within and between group differences in the blood pressures (p = 0.000). Conclusion To stem the tide of female hypertension later in life, child bearing should not start in the early teenage years nor be unnecessarily delayed. Sociocultural conditions that promote early teenage marriage and pregnancy should be discouraged.

Blood-pressure targets in comatose survivors of cardiac arrest with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention - a BOX sub-study

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Novo Nordisk Foundation. Background After successful resuscitation from out-of-hospital cardiac arrest (OHCA), patients who remain comatose often need hemodynamic support with vasoactive drugs in order to secure an adequate perfusion pressure to vital organs. However, evidence regarding specific blood-pressure targets is sparse, and patients with concomitant heart disease such as acute ST-elevation myocardial infarction (STEMI) might benefit from a lower afterload and lower doses of vasoactive drugs. Purpose To assess the impact of blood-pressure on biochemical infarct size in comatose survivors of OHCA with STEMI and, further, to investigate whether a high or low mean arterial blood-pressure target is superior in preventing death or severe brain injury. Methods The BOX study (n=789) is a randomized trial with a 2-by-2 factorial design which evaluated a double-blind intervention of a high (77 mmHg) versus a low (63 mmHg) mean arterial blood-pressure target in comatose survivors of OHCA of presumed cardiac cause. In this pre-specified sub-study we included patients who had an initial electrocardiogram with STEMI recorded after return of spontaneous circulation (ROSC). The primary outcome was creatine kinase (CK), creatine kinase MB (CKMB), and troponin T (TnT) levels measured at 48 hours as surrogate markers of infarct size. A secondary outcome was a composite of all-cause death within one year from admission or discharge from the hospital with a Cerebral Performance Category (CPC) of 3 to 4, indicating severe neurological disability or a comatose or vegetative state. Results A total of 350 patients were included. Mean time to ROSC was 21±13 minutes. The mean age was 63±12 years and approximately 4 out of 5 were male. The prevalence of relevant prior medical history was as follows; hypertension 42%, diabetes 12%, chronic ischemic heart disease 20%, percutaneous coronary intervention 11%, coronary artery bypass grafting 4%, and congestive heart failure 10%. Mean CK, CKMB and TnT measured at 48 hours did not differ between the two blood-pressure target groups (p=0.42, p=0.14 and p=0.65, respectively). Within one year, 138 patients (39%) had died or been discharged with a CPC of 3 to 4 with no difference found between high or low blood pressure targets (hazard ratio, 1.02; 95% CI, 0.73-1.43; p=0.9). Conclusion Targeting a high versus a low mean arterial blood-pressure in comatose survivors of OHCA with STEMI did not affect infarct size estimated by coronary biomarkers at 48 hours nor did it result in a significant difference in death or severe neurologic disability. Although not evaluating side effects, this study thus suggests that the use of pharmacologic circulatory support in post-resuscitation care can be limited.

Stemming The Tide Of Hypertension In Women: Optimal Age For Obstetric Debut

Objective Women have continued to bear a heavy burden of cardiovascular disease morbidity and mortality with hypertension as the flagship. This is partly because as the modifiable cardiovascular disease risk factors are falling in rate, gender specific risk factors have persisted. One of them is age at first pregnancy and delivery. Methods In order to contribute to this discourse, we secondarily analysed data generated in a previous field study on risk factors for cardiovascular diseases in free living adults in Plateau State, Nigeria. The women were divided into four groups and we looked at blood pressure at the time of study from the perspective of age at first pregnancy. Reults It was found that those who had their first pregnancy in the late teenage years had the lowest mean arterial blood pressure many years down the line; better than those who started child bearing earlier and those who started later. There was also significant within and between group differences in the blood pressures (p = 0.000). Conclusion To stem the tide of female hypertension later in life, child bearing should not start in the early teenage years nor be unnecessarily delayed. Sociocultural conditions that promote early teenage marriage and pregnancy should be discouraged.

Higher blood pressure versus normotension targets to prevent acute kidney injury: a systematic review and meta-regression of randomized controlled trials

BackgroundRenal hypoperfusion is one of the most common causes of acute kidney injury (AKI), especially in shock and perioperative patients. An optimal blood pressure (BP) target to prevent AKI remains undetermined. We conducted a systematic review and meta-analysis of available randomized clinical trial (RCT) results to address this knowledge gap.MethodsFrom inception to May 13, 2022, we searched Ovid Medline, EMBASE, Cochrane Library, SCOPUS, clinicaltrials.gov, and WHO ICTRP for RCTs comparing higher BP target versus normotension in hemodynamically unstable patients (shock, post-cardiac arrest, or surgery patients). The outcomes of interest were post-intervention AKI rate and renal replacement therapy (RRT) rate. Two investigators independently screened the citations and reviewed the full texts for eligible studies according to a predefined form.ResultsTwelve trials were included, enrolling a total of 5759 participants, with shock, non-cardiac, and cardiac surgery patients accounting for 3282 (57.0%), 1687 (29.3%) and 790 (13.7%) patients, respectively. Compared to lower mean arterial blood pressure (MAP) targets that served as normotension, targeting higher MAP had no significant effect on AKI rates in shock (RR [95% CI] = 1.10 [0.93, 1.29]), in cardiac-surgery (RR [95% CI] = 0.87 [0.73, 1.03]) and non-cardiac surgery patients (RR [95% CI] = 1.25 [0.98, 1.60]) using random-effects meta-analyses. In shock patients with premorbid hypertension, however, targeting MAP above 70 mmHg resulted in significantly lower RRT risks, RR [95%CI] = 1.20 [1.03, 1.41], p < 0.05.ConclusionsTargeting a higher MAP in shock or perioperative patients may not be superior to normotension, except in shock patients with premorbid hypertension. Further studies are needed to assess the effects of a high MAP target to preventing AKI in hypertensive patients across common settings of hemodynamic instability.Trial registration This systematic review has been registered on PROSPERO (CRD42021286203) on November 19, 2021, prior to data extraction and analysis.

Predictors of hypotension during anesthesia induction in patients with hypertension on medication: a retrospective observational study

BackgroundHypotension during anesthesia induction is a common event, and occurs more frequently in patients with hypertension than in healthy individuals. Intraoperative hypotension in non-cardiac surgery is reportedly associated with various postoperative complications. However, the predictors of hypotension during anesthesia induction in patients with hypertension have not yet been ascertained. Therefore, we aimed to determine the predictors of hypotension during anesthesia induction in patients with hypertension on medication focusing on the half-life of the medication used.MethodsIn this retrospective observational study, we enrolled patients with hypertension on medication who underwent general anesthesia for oral and maxillofacial surgery between January 1, 2013, and December 31, 2019. Multivariable logistic regression analysis was conducted to test for associations between clinical factors and hypotension during anesthesia induction in patients with hypertension on medication.ResultsA total of 395 patients were included in this study. The risk factors for hypotension during anesthesia induction in patients with hypertension on medication were pre-induction mean arterial blood pressure (adjusted unit odds ratio, 0.96 [95% confidence interval, 0.94 to 0.98]), female sex (adjusted odds ratio [aOR], 1.63 [1.03 to 2.57]), regular use of angiotensin receptor blockers (ARBs)/angiotensin-converting enzyme inhibitors (ACE-Is) with a long half-life (vs. no regular use of ARBs/ACE-Is aOR, 4.02 [1.77 to 9.12]; vs. regular use of ARBs/ACE-Is with a short-to-middle half-life aOR, 3.17 [1.46 to 6.85]), and regular use of beta blockers (aOR, 2.45 [1.19 to 5.04]). Regular use of calcium channel blockers (aOR, 0.44 [0.25 to 0.77]) was a suppressive factor for hypotension during anesthesia induction in patients with hypertension.ConclusionsIn patients with hypertension on medication, regular use of ARBs/ACE-Is with a long half-life, regular use of beta blockers, low pre-induction mean arterial blood pressure, and female sex were risk factors for hypotension during anesthesia induction. Notably, regular use of ARBs/ACE-Is with a long half-life was a high-risk factor for hypotension during anesthesia induction in patients with hypertension on medication even after a 24-h preoperative withdrawal period.

Protocol for an individual patient data meta-analysis on blood pressure targets after cardiac arrest.

BackgroundHypotension is common after cardiac arrest (CA), and current guidelines recommend using vasopressors to target mean arterial blood pressure (MAP) higher than 65 mmHg. Pilot trials have compared higher and lower MAP targets. We will review the evidence on whether higher MAP improves outcome after cardiac arrest.MethodsThis systematic review and meta‐analysis will be conducted based on a systematic search of relevant major medical databases from their inception onwards, including MEDLINE, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL), as well as clinical trial registries.We will identify randomised controlled trials published in the English language that compare targeting a MAP higher than 65–70 mmHg in CA patients using vasopressors, inotropes and intravenous fluids. The data extraction will be performed separately by two authors (a third author will be involved in case of disagreement), followed by a bias assessment with the Cochrane Risk of Bias tool using an eight‐step procedure for assessing if thresholds for clinical significance are crossed. The outcomes will be all‐cause mortality, functional long‐term outcomes and serious adverse events. We will contact the authors of the identified trials to request individual anonymised patient data to enable individual patient data meta‐analysis, aggregate data meta‐analyses, trial sequential analyses and multivariable regression, controlling for baseline characteristics. The certainty of the evidence will be assessed by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. We will register this systematic review with Prospero and aim to redo it when larger trials are published in the near future.ConclusionsThis protocol defines the performance of a systematic review on whether a higher MAP after cardiac arrest improves patient outcome. Repeating this systematic review including more data likely will allow for more certainty regarding the effect of the intervention and possible sub‐groups differences.

EFFECT OF SEVERE FOOD RESTRICTION ON BLOOD PRESSURE REGULATION IN THE FEMALE SPRAGUE DAWLEY RAT

Objective: Eating disorders have both short term and long term consequences that can be present years after recovery. However, the molecular mechanisms contributing to the increased cardiovascular risk for “recovered’’ individuals is still largely unknown. We have previously found that inbred female F344 rats have altered renin-angiotensin-aldosterone-system regulation of mean arterial blood pressure(MAP) following a 60% food restriction (to achieve a 15–20% body weight drop in F344). The purpose of this work was to see if these are robust changes that can be replicated in an outbred strain which is a better model of the human population. Design and method: Two-month-old female Sprague Dawley(SD) rats were divided into control(CON) that had access to food ad libitum and a food restricted(FR) that received a 56% food restriction (to achieve a 15–20% body weight drop in SD). After 2 weeks, CON (n = 5) and FR (n = 5) rats were sacrificed, the remaining FR (n = 4) and CON (n = 4) rats received chow ad libitum for 5 months. Prior to sacrifice, an acute MAP response to 200ng/kg Angiotensin II(ANGII) was recorded from the femoral artery under anesthesia by indwelling catheter. Results: We found that after 14 days of food restriction the FR rats had lower baseline MAP compared to CON rats (CON = 92 ± 3.0 vs. FR = 75 ± 0.4mmHG, p &lt; 0.05), however, both groups had the same absolute response in MAP to ANGII infusion (CON = 19 ± 2.8 vs. FR = 18 ± 2.0 mmHG). After 5 months of refeeding we found that there were no statistical differences in baseline MAP between the groups (CON = 86 ± 2.2 vs. FR = 91 ± 4.8mmHg), however, there was a trend towards an increase in peak MAP response to ANGII (CON = 19 ± 1.5 vs. FR = 27 ± 3.0mmHg, p = 0.056). Conclusions: When compared to F344, we found similar trends in baseline MAP immediately following food restriction and months after refeeding. We did not detect a blunting of the ANGII response immediately following food restriction as in F344. We did find similarities between F344 and SD in response to ANGII months after refeeding. Food restriction appears to create a robust change in the response to ANGII months after refeeding, that is not strain specific.

Associations between maternal iron supplementation in pregnancy and offspring growth and cardiometabolic risk outcomes in infancy and childhood.

It was previously observed that maternal iron supplementation in pregnancy was associated with increased offspring size and adiposity at birth, possibly mediated through increased risk of gestational diabetes. In this study we investigated potential long-term associations of maternal iron supplementation in pregnancy with offspring growth in infancy, and growth and cardiometabolic risk factors in mid-childhood to seek evidence of nutritional programming. Using a nested case-control format, markers of growth and adiposity were measured at 3, 12 and 24 months of age in 341 infants from the Cambridge Baby Growth Study whose mothers supplemented with iron in pregnancy and 222 infants whose mothers did not. Measures of growth, glucose tolerance (using a 30 minute 1.75 g glucose/kg body weight oral glucose tolerance test), insulin sensitivity (HOMA IR) and blood pressure were collected in 122 and 79 of these children, respectively, at around 9.5 years of age. In infancy adiposity-promoting associations with maternal iron supplementation in pregnancy were evident at 3 months of age (e.g. mean difference in skinfold thickness: β = +0.15 mm, p = 0.02, in n = 341 whose mothers supplemented versus 222 that did not; waist circumference: β = +0.7 cm, p = 0.04, in n = 159 and 78, respectively) but differences lessened after this time (e.g. 3–12 month change in mean difference in skinfold thickness: β = -0.2 mm, p = 0.03, in n = 272 and 178, respectively). At ~9.5 years of age children whose mothers supplemented with iron in pregnancy had lower mean arterial blood pressures (β = -1.0 mmHg, p = 0.03, in n = 119 and 78, respectively). There were no apparent differences in markers of growth or other cardiometabolic factors. These results suggest that most of the associations of maternal iron supplementation in pregnancy on growth and adiposity evident at birth disappear during infancy, but there may be some evidence of long-term nutritional programming of blood pressure in mid-childhood.

Antihypertensive and Vasorelaxant Effects of Hibiscus rosa-sinensis through Angiotensin-Converting Enzyme-2 (ACE-2), and Ca2+ channels Pathways.

The aim of the study was to assess the antihypertensive activity of Hibiscus rosa-sinensis. Hibiscus rosa-sinensis is used traditionally to treat hypertension. The goal of the study was to investigate the effect of the aqueous extract of Hibiscus rosa-sinensis flowers (AEHRS) on resting blood pressure in rats. In the present study, AEHRS was prepared and its antihypertensive activity was evaluated using in vivo and in vitro studies. In the in vivo study, hypertensive and normotensive rats were treated by AEHRS (100 mg/kg) orally for 6 hours in the acute treatment and for 7 days in the subchronic treatment. Systolic, diastolic, and mean arterial blood pressure values and heart rate were then recorded using a tail cuff and a computer-assisted monitoring device. To assess the vasorelaxant activity of AEHRS, isolated thoracic aortic rings were suspended in a tissue bath and changes in tension were recorded using a data acquisition system. Potential pathways involved in the vasorelaxant activity were evaluated using several standard pharmacological agents. The results indicated that repeated oral administration of AEHRS during 7 days lowered systolic, diastolic, and mean arterial blood pressure in hypertensive rats without affecting normotensive rats. Furthermore, the data revealed that AEHRS exerts vasorelaxant properties via an endothelium-independent pathway. More interestingly, the study demonstrates that the vasorelaxant capacity of AEHRS seems to be exerted through the stimulation of angiotensin-converting enzyme-2 (ACE-2) and the inhibition of Ca2+ channels pathway. The present study revealed that aqueous extract of Hibiscus rosa-sinensis has a significant antihypertensive activity and that its vasorelaxant effect may be mediated through stimulation of ACE-2, and inhibition of the Ca2+ channels.

Thoracic Epidural Versus General Anaesthesia For Laparoscopic Cholecystectomy: A Randomized Controlled Trial.

Laparoscopic cholecystectomy is one of the most commonly performed surgeries worldwide. Aim of our study was to compare the effectiveness of thoracic epidural anaesthesia with general anaesthesia for Laparoscopic cholecystectomy in terms of changes in blood pressure during surgery, postoperative pain, respiratory complications and average length of hospital stay. It was a randomized controlled trial conducted from 1stOctober 2018 to 31st October 2019. Eightytwo patients planned to undergo elective laparoscopic cholecystectomy were randomly divided into two groups, T and G. In Group T all patients underwent laparoscopic cholecystectomy under thoracic epidural anaesthesia with 12 ml of 0.25% bupivacaine and 1% lignocaine plain whereas in group G all patients underwent surgery under general anaesthesia. Intra-operative mean arterial pressure (MAP) and postoperative opioid consumption in first 24hrs were recorded as primary outcomes whereas presence or absence of respiratory complication and duration of hospital stay as secondary outcome.. Out of 82 patients, 41 patients underwent laparoscopic cholecystectomy under thoracic epidural anaesthesia and 41 patients had surgery under general anaesthesia. Mean arterial pressure was lower in Group T and the difference was statistically significant. The average time of first complaint of postoperative pain in Group T was 5.4±1.26 hours as compared to less than 0.79±0.25 hours in Group G. Patients in group T required lower doses of opioid analgesia in first twenty-four hours as compared to patients in group G. Mean hospital stay in group T was 1 day as compared to 3 days in group G. Thoracic epidural anaesthesia provides a better alternative to general anaesthesia for Laparoscopic cholecystectomy with lower intraoperative mean arterial blood pressure, 24 hours postoperative consumption of opioids, respiratory complications and length of hospital stay.

Predictors of stroke favorable functional outcome in Guinea, results from the Conakry stroke registry

Low- to middle-income countries (LMICs) now bear most of the stroke burden. In LMICs, stroke epidemiology and health care systems are different from HICs. Therefore, a high-income country (HIC)-based predictive model may not correspond to the LMIC stroke context. Identify the impact of modifiable variables in acute stroke management in Conakry, Guinea as potential predictors of favorable stroke outcome. Data were extracted from the Conakry stroke registry that includes 1018 patients. A logistic regression model was built to predict favorable stroke outcomes, defined as mRS 0–2. Age, admission NIHSS score, mean arterial blood pressure and capillary glycemia were chosen as covariates. Delay to brain CT imaging under 24 h from symptom onset, fever, presence of sores and abnormal lung auscultation were included as factors. NIHSS score on admission, age and ischemic stroke were included in the null model as nuisance parameters to determine the contribution of modifiable variables to predict stroke favorable outcome. Lower admission NIHSS, brain CT imaging within 24 h of symptoms onset and lower mean arterial blood pressure emerged as a significant positive predictors of favorable stroke outcome with respective odd ratios (OR) of 1.35 [1.28–1.43], 2.1 [1.16–3.8] and 1.01 [1.01–1.04]. The presence of fever or sores impacted negatively stroke favorable outcomes with OR of 0.3 [0.1–0.85] and 0.25 [0.14–0.45]. The area under receiver operating characteristic curves (AUC) of the model was 0.86. This model explained 44.5% of the variability of the favorable stroke outcome with 10.2% of the variability explained by the modifiable variables when admission NIHSS, and ischemic stroke were included in the null model as nuisance parameter. In the Conakry stroke registry, using a logistic regression to predict stroke favorable outcome, five variables that led to an AUC of 0.86: admission NIHSS, early brain CT imaging, fever, sores and mean blood pressure. This paves the way for future public health interventions to test whether modulating amendable variables leads to increased favorable stroke outcomes in LMICs.