Mean Arterial Pressure Research Articles

Effects of intrarenal pelvic infusion of tumour necrosis factor-α and interleukin 1-β on reno-renal reflexes in anaesthetised rats.

Reno-renal reflexes are disturbed in cardiovascular and hypertensive conditions when elevated levels of pro-inflammatory mediators/cytokines are present within the kidney. We hypothesised that exogenously administered inflammatory cytokines tumour necrosis factor alpha (TNF-α) and interleukin (IL)-1β modulate the renal sympatho-excitatory response to chemical stimulation of renal pelvic sensory nerves. In anaesthetised rats, intrarenal pelvic infusions of vehicle [0.9% sodium chloride (NaCl)], TNF-α (500 and 1000 ng/kg) and IL-1β (1000 ng/kg) were maintained for 30 min before chemical activation of renal pelvic sensory receptors was performed using randomized intrarenal pelvic infusions of hypertonic NaCl, potassium chloride (KCl), bradykinin, adenosine and capsaicin. The increase in renal sympathetic nerve activity (RSNA) in response to intrarenal pelvic hypertonic NaCl was enhanced during intrapelvic TNF-α (1000 ng/kg) and IL-1β infusions by almost 800% above vehicle with minimal changes in mean arterial pressure (MAP) and heart rate (HR). Similarly, the RSNA response to intrarenal pelvic adenosine in the presence of TNF-α (500 ng/kg), but not IL-1β, was almost 200% above vehicle but neither MAP nor HR were changed. There was a blunted sympatho-excitatory response to intrapelvic bradykinin in the presence of TNF-α (1000 ng/kg), but not IL-1β, by almost 80% below vehicle, again without effect on either MAP or HR. The renal sympatho-excitatory response to renal pelvic chemoreceptor stimulation is modulated by exogenous TNF-α and IL-1β. This suggests that inflammatory mediators within the kidney can play a significant role in modulating the renal afferent nerve-mediated sympatho-excitatory response.

The role of preterm birth in stress-induced sodium excretion in young adults.

Early-life programming due to prematurity and very low birth weight (VLBW, <1500 g) is believed to contribute to development of hypertension, but the mechanisms remain unclear. Experimental data suggest that altered pressure natriuresis (increased renal perfusion pressure promoting sodium excretion) may be a contributing mechanism. We hypothesize that young adults born preterm will have a blunted pressure natriuresis response to mental stress compared with those born term. In this prospective cohort study of 190 individuals aged 18-23 years, 156 born preterm with VLBW and 34 controls born term with birth weight at least 2500 g, we measured urine sodium/creatinine before and after a mental stress test and continuous blood pressure before and during the stress test. Participants were stratified into groups by the trajectory at which mean arterial pressure (MAP) increased following the test. The group with the lowest MAP trajectory was the reference group. We used generalized linear models to assess poststress urine sodium/creatinine relative to the change in MAP trajectory and assessed the difference between groups by preterm birth status. Participants' mean age was 19.8 years and 57% were women. Change in urine sodium/creatinine per unit increase in MAP when comparing middle trajectory group against the reference group was greater in those born preterm [β 5.4%, 95% confidence interval (95% CI) -11.4 to 5.3] than those born term (β 38.5%, 95% CI -0.04 to 92.0), interaction term P = 0.002. We observed that, as blood pressure increased following mental stress, young adults born preterm exhibited decreased sodium excretion relative to term-born individuals.

Study on blood pressure rhythm in hypertensive patients withdeficiency syndrome and a random forest model for predicting hypertension withdeficiency syndrome.

To investigate blood pressure rhythm (BPR) in Yin deficiency syndrome of hypertension (YDSH) patients and develop a random forest model for predicting YDSH. Our study was consistent with technical processes and specification for developing guidelines of Evidence-based Chinese medicine clinical practice (T/CACM 1032-2017). We enrolled 234 patients who had been diagnosed with primary hypertension without antihypertensive medications prior to the enrollment. All participants were divided into Yin deficiency group (YX, n = 74) and non-Yin deficiency group (NYX, n = 160). Participants were professionally grouped by three experienced chief Traditional Chinese Medicine (TCM) physicians according to four examinations (i.e., inspection, listening and smelling, inquiry and palpation). We collected data on 24 h ambulatory blood pressure monitoring (ABPM) and YDSH rating scale. We divided 24 h of a day into 12 two-hour periods [Chen-Shi (7:00-9:00), Si-Shi (9:00-11:00), Wu-Shi (11:00-13:00), Wei-Shi (13:00-15:00), Shen-Shi (15:00-17:00), You-Shi (17:00-19:00), Xu-Shi (19:00-21:00), Hai-Shi (21:00-23:00), Zi-Shi (23:00-1:00), Chou-Shi (1:00-3:00), Yin-Shi (3:00-5:00), Mao-Shi (5:00-7:00)] according to the theory of "midnight-midday ebb flow". We used random forest to build the diagnostic model of YDSH, with whether it was Yin deficiency syndrome as the outcome. Compared with NYX group, YX group had more female participants with older age, lower waist circumference, body mass index (BMI), diastolic blood pressure (DBP), and smoking and drinking rate (all P ＜ 0.05). The YDSH rating scores of YX group [28.5 (21.0-36.0)] were significantly higher than NYX group [13.0 (8.0-22.0)] (P < 0.001), and the typical symptoms of YX group included vexing heat in the chest, palms and soles, dizziness, dry eyes, string-like and fine pulse, soreness and weakness of lumbus and knees, palpitations, reddened cheeks, and tinnitus (all P < 0.05). The ratio of non-dipper hypertension in YX group was higher than in NYX group (56.9% vs 44.4%, P = 0.004). Compared with NYX group, 24 h DBP standard deviation (SD), nighttime DBP SD, Si-Shi DBP, Si-Shi mean arterial pressure (MAP), Hi-Shi systolic blood pressure (SBP), Hi-Shi DBP, Hi-Shi MAP, Zi-Shi SBP, Zi-Shi DBP, Zi-Shi MAP, Chou-Shi SBP SD, Chou-Shi DBP SD, Chou-Shi SBP coefficient of variation (CV) were lower in YX group (all P ＜ 0.05). Binary Logistic Regression analysis showed that the diagnosis of YDSH was positively correlated with age, heart rate, YDSH rating scores, and four TCM symptoms including vexing heat in the chest, palms and soles, string-like and fine pulse, soreness and weakness of lumbus and knees, and reddened cheeks (all P ＜ 0.05), but was negatively correlated with smoking (P﹥0.05). In addition, the diagnosis of YDSH was positively correlated with daytime SBP SD, nighttime SBP SD, nighttime SBP CV, and Hi-Shi SBP CV, but was negatively correlated with 24 h SBP CV, daytime DBP SD, nighttime DBP SD, and Hi-Shi DBP (all P ＜ 0.05). Hi-Shi SBP CV had independent and positive correlation with the diagnosis of YDSH after adjusting the variables of age, gender, course of hypertension, BMI, waist circumference, SBP, DBP, heart rate, smoking and drinking (P = 0.029). Diagnostic model of YDSH was established and verified based on the random forest. The results showed that the calculation accuracy, specificity and sensitivity were 77.3%, 77.8% and 76.9%, respectively. The BPR was significantly attenuated in YDSH patients, including lower 24 h DBP SD and nighttime DBP SD, and Hi-Shi SBP CV is independently correlated with the diagnosis of YDSH. The prediction accuracy of diagnosis model of YDSH based on the random forest was good, which could be valuable for clinicians to differentiate YDSH and non-Yin deficiency patients for more effective hypertensive treatment of TCM.

Impact of arginine-vasopressin on regional perfusions in a porcine model of post-resuscitation syndrome

BackgroundPost-cardiac arrest (CA) shock is associated with multiple organ failure, including acute kidney injury, and is the leading cause of early death among patient successfully resuscitated from CA. Arginine-vasopressin (AVP) may be an interesting therapeutic alternative or complement to noradrenaline (NAD) to both control shock and preserve regional, especially renal, organ perfusions. Methods18 swine (24–39 kg) were submitted to 14 min of ventricular fibrillation and cardio-pulmonary resuscitation. After return of spontaneous circulation (ROSC), animals randomly received either AVP, NAD or AVP-NAD combination for maintaining a targeted mean arterial pressure of 70 ± 5 mmHg for 6 h. Haemodynamic and biological parameters, including kidney function biomarkers and diuresis, were monitored throughout the follow-up. ResultsTargeted mean arterial pressure was successfully obtained in the NAD (n = 6) and the AVP-NAD (n = 6) groups, but not in the AVP group (n = 6), where 4 animals died. As compared to NAD alone, renal blood flow (2.9 ± 1.15 vs 4.36 ± 0.64 mL//kg/min in NAD and AVP-NAD groups) and diuresis were higher in the AVP-NAD group. This was associated with a reduction of carotid blood flow and a more severe metabolic acidosis during the first 3 h of follow-up in the AVP-NAD group as compared to NAD group. ConclusionCombination of AVP and NAD improved renal perfusion and diuresis but reduced carotid blood flow as compared to NAD alone in a porcine model of post-resuscitation syndrome. AVP alone failed to manage shock and led to mortality.

The regulatory effects of serum catecholamines and endothelial cells in pig hemorrhagic shock and fluid resuscitation models

BackgroundAcute blood loss not only leads to systemic compensatory response, but also the induced changes in vascular endothelial function.These pathological changes may have potential compensatory significance for maintaining organ perfusion and fluid resuscitation. ObjectiveTo understand trauma-induced endotheliopathy and their compensatory roles in acute hemorrhage, a porcine model of hemorrhagic shock (HS) was used to evaluate changes in vascular endothelial factors and catecholamine levels at different time points from shock to fluid resuscitation. Methods: HS was induced in female pigs by rapid bleeding via the arterial sheath. Hemodynamic monitoring was performed using a pulse index continuous cardiac output (PiCCO) system in HS and fluid resuscitation. Femoral vein blood samples were collected at baseline and 40% mean arterial pressure (MAP, shock), MAP recovery, and 30 min, 1 h, and 2 h after recovery. Serum levels of catecholamine and Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), Tie-2, Eselectin, intracellular adhesion molecule-1 (ICAM-1), soluble thrombomodulin (sTM), and Syndecan-1 (SDC-1) were evaluated using enzyme-linked immunosorbent assay (ELISA). ResultsSerum catecholamine levels were significantly higher in the shock than in the baseline state. Ang-1 and Ang-2 are endothelial growth factors secreted with distinct roles. Ang-1 stabilizes the endothelium and inhibits vascular leakage, and Ang-2 has the opposite effect. The ratio of Ang-2/Ang-1 was significantly higher in the shock state than in the baseline state; however, the Ang-1/Tie-2 ratio was comparable between the two states. This suggests that changes in vascular permeability may mainly depend on the upregulation of Ang-2 function. Serum levels of E-selectin, ICAM-1, sTM, and SDC-1 were significantly higher in the shock state than in the baseline state. After the MAP was restored to the baseline state, the levels of E-selectin, and SDC-1 remained higher compared with the baseline state until 1 h after MAP recovery. Conclusions: serum levels of catecholamines and vascular endothelial markers increased transiently under HS, promoting a compensatory response of the circulatory system to acute bleeding. This may be one of the potential theoretical basis for restrictive fluid resuscitation.

Validation of oscillometric ratio and maximum gradient methods for non-invasive blood pressure measurement with intra-arterial blood pressure measurements as reference.

Most non-invasive blood pressure (BP) measurements are carried out using instruments which implement either the Ratio or the Maximum Gradient oscillometric method, mostly during cuff deflation, but more rarely during cuff inflation. Yet, there is little published literature on the relative advantages and accuracy of these two methods. In this study of 40 lightly sedated individuals aged 64.1 ± 9.6 years, we evaluate and compare the performance of the oscillometric ratio (K) and gradient (Grad) methods for the non-invasive estimation of mean pressure, SBP and DBP with reference to invasive intra-arterial values. There was no significant difference between intra-arterial estimates of mean pressure made via Korotkoff sounds (MP-OWE) or the gradient method (MP-Grad). However, 17.7% of MP-OWE and 15% of MP-Grad were in error by more than 10 mmHg. SBP-K and SBP-Grad underestimated SBP by 14 and 18 mmHg, whilst accurately estimating DBP with mean errors of 0.4 ± 5.0 and 1.7 ± 6.1 mmHg, respectively. Relative to the reference standard SBP-K, SBP-Grad and DBP-Grad were estimated with a mean error of -4.5 ± 6.6 and 1.4 ± 5.6 mmHg, respectively, noting that using the full range of recommended ratios introduces errors of 12 and 7 mmHg in SBP and DBP, respectively. We also show that it is possible to find ratios which minimize the root mean square error (RMSE) and the mean error for any particular individual cohort. We developed linear models for estimating SBP and SBP-K from a range of demographic and non-invasive OWE variables with resulting mean errors of 0.15 ± 5.6 and 0.3 ± 5.7 mmHg, acceptable according to the Universal standard.

C-reactive protein to albumin ratio and risk of incident metabolic syndrome in community-dwelling adults: longitudinal findings over a 12-year follow-up period.

The C-reactive protein to albumin (CRP/Alb) ratio has emerged as a novel biomarker for various inflammatory diseases. This study aimed to evaluate the association between the CRP/Alb ratio and incident metabolic syndrome (MetS) with a large-sample, community-based Korean cohort over a 12-year follow-up period. Among 10,030 participants, a total of 6205 participants aged 40-69 years without MetS were selected from the Korean Genome and Epidemiology Study (KoGES). The baseline CRP/Alb ratio was divided into quartiles. The definition of newly developed MetS was the one proposed by the 2009 Joint Interim Statement of Circulation. Hazard ratios (HRs) with 95% confidence intervals (CIs) for incident MetS were calculated using multivariable Cox proportional hazards regression models after adjusting for potentially confounding variables. During the 12-year follow-up period, MetS developed in 2535 subjects (40.9%, 2535/6205) with an incidence rate of 5.6-11.9 (over 2 years). Compared to the reference first quartiles, the HRs (95% CIs) of incident MetS in the second, third, and fourth quartiles increased in a dose-response manner. Compared to the reference quartile, the HRs (95% CIs) of the incidence of MetS for the second, third, and fourth quartiles of CRP/Alb ratio were 1.12 (0.99-1.27), 1.24 (1.11-1.40), and 1.51 (1.34-1.69) after adjusting for age, sex, smoking status, alcohol intake, physical activity, total cholesterol, mean arterial pressure, HOMA-IR, and total energy intake. High CRP/Alb ratio at baseline may be a useful surrogate indicator of future incident MetS.

Impact of Ultrafiltration Profiling Compared to Conventional Methods on Blood Pressure Regulation Among Hemodialysis Patients

Background: Standard hemodialysis sessions pose challenges for patients due to fluctuations in blood pressure. Alternative strategies, such as ultrafiltration profiling, have been proposed as potentially more effective treatments. Objectives: This study aimed to evaluate the effects of ultrafiltration profiling compared to the conventional method on blood pressure regulation among hemodialysis patients. Methods: This study employed a pre-test and post-test design, involving a single group of 30 hemodialysis patients undergoing treatment at Shahid Beheshti Hospital in Hamadan in 2022. The sampling method used was simple random sampling. The intervention consisted of three sessions using the routine method, followed by three sessions utilizing the ultrafiltration profile method, which employed an interval with a negative slope. Demographic and clinical information about the patients was recorded on a checklist. Systolic and diastolic blood pressure measurements were taken before the commencement of hemodialysis, at 1-, 2-, and 3-hour intervals post-treatment initiation, and again 15 minutes after completing hemodialysis. Results: The mean blood pressure changes observed during dialysis stages increased with both methods; however, there was a significant difference between the methods (P &lt; 0.001). Specifically, patients receiving the ultrafiltration profile method experienced significantly lower increases in blood pressure compared to those receiving the routine method. Conclusions: Based on the research results, integrating ultrafiltration profiling into hemodialysis can be regarded as an effective and viable strategy for enhancing blood pressure regulation in patients undergoing hemodialysis treatment. Therefore, it is recommended that this approach be considered in hemodialysis programs as well.

The effect of deep and awake extubation on emergence agitation after nasal surgery: a randomized controlled trial

BackgroundPost-anesthetic emergence agitation is common after general anesthesia and may cause adverse consequences, such as injury as well as respiratory and circulatory complications. Emergence agitation after general anesthesia occurs more frequently in nasal surgery than in other surgical procedures. This study aimed to assess the occurrence of emergence agitation in patients undergoing nasal surgery who were extubated under deep anesthesia or when fully awake.MethodsA total of 202 patients (18–60 years, American Society of Anesthesiologists classification: I–II) undergoing nasal surgery under general anesthesia were randomized 1:1 into two groups: a deep extubation group (group D) and an awake extubation group (group A). The primary outcome was the incidence of emergence agitation. The secondary outcomes included number of emergence agitations, sedation score, vital signs, and incidence of adverse events.ResultsThe incidence of emergence agitation was lower in group D than in group A (34.7% vs. 72.8%; p < 0.001). Compared to group A, patients in group D had lower Richmond Agitation-Sedation Scale scores, higher Ramsay sedation scores, fewer agitation episodes, and lower mean arterial pressure when extubated and 30 min after surgery, whereas these indicators did not differ 90 min after surgery. There was no difference in the incidence of adverse events between the two groups.ConclusionsExtubation under deep anesthesia can significantly reduce emergence agitation after nasal surgery under general anesthesia without increasing the incidence of adverse events.Trial registrationRegistered in Clinicaltrials.gov (NCT04844333) on 14/04/2021.

Post-anesthesia care unit hypotension in low-risk patients recovering from non-cardiac surgery: a prospective observational study.

Intraoperative hypotension is common and associated with organ injury. Hypotension can not only occur during surgery, but also thereafter. After surgery, most patients are treated in post-anesthesia care units (PACU). The incidence of PACU hypotension is largely unknown - presumably in part because arterial pressure is usually monitored intermittently in PACU patients. We therefore aimed to evaluate the incidence, duration, and severity of PACU hypotension in low-risk patients recovering from non-cardiac surgery. In this observational study, we performed blinded continuous non-invasive arterial pressure monitoring with finger-cuffs (ClearSight system; Edwards Lifesciences, Irvine,CA, USA) in 100 patients recovering from non-cardiac surgery in the PACU. We defined PACU hypotension as a mean arterial pressure (MAP) < 65 mmHg. Patients had continuous finger-cuff monitoring for a median (25th percentile, 75th percentile) of 64 (44 to 91) minutes. Only three patients (3%) had PACU hypotension for at least one consecutive minute. These three patients had 4, 4, and 2 cumulative minutes of PACU hypotension; areas under a MAP of 65 mmHg of 17, 9, and 9 mmHg x minute; and time-weighted averages MAP less than 65 mmHg of 0.5, 0.3, and 0.2 mmHg. The median volume of crystalloid fluid patients were given during PACU treatment was 200 (100 to 400) ml. None was given colloids or a vasopressor during PACU treatment. In low-risk patients recovering from non-cardiac surgery, the incidence of PACU hypotension was very low and the few episodes of PACU hypotension were short and of modest severity.

The management of goal-directed fluid therapy during cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

Cytoreductive surgery is a surgical treatment approach that has been applied over the last 3 decades in patients with peritoneal metastases originating from intraabdominal organs. Goal-directed fluid therapy (GDFT) is an approach in which a patient fluid therapy during a medical procedure or surgery is carefully managed based on a specific goal. In this study, we aimed to present the results of GDFT in patients who underwent cytoreductive surgery for peritoneal carcinomatosis (PC) during the perioperative period. This retrospective study included 398 patients patient who underwent cytoreductive surgery + hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) due to PC originating from intraabdominal malignancies. Of the cases, 233 (58.6%) were female, and 165 (41.4%) were male patients. The mean age was 58.9. Perioperative findings revealed an average PC score of 12 (3-24), average lactate levels of 3 (2-7) mmol/L, Pao2/fio2 of 3.3 (2.4-4.1) mm Hg, mean arterial pressure (MAP) of 60 (55-70), average surgery duration of 6.5 hours (3-14), and average blood loss of 400 (200-4000) cc. The mean intraoperative fluid rate was 6.4 mL/kg/h (IQR 5.8-7.1). Sixteen (16.3%) patients experienced Clavien-Dindo Grade 3-4 adverse events. Within 30 days, 25 patients (6.3%) died. CRS + HIPEC procedures utilizing perioperative GDFT along with advanced anesthesia monitoring devices have shown successful application, offering an alternative to traditional and restrictive fluid management approaches.

Upstroke time is a more useful marker of atherosclerosis than percentage of mean arterial pressure for detecting coronary artery disease in subjects with a normal ankle-brachial index.

Upstroke time (UT) and percentage of mean arterial pressure (%MAP) at the ankle have been shown to serve as atherosclerotic markers. The purpose of this study was to directly compare the diagnostic accuracy of UT with that of %MAP for clinical coronary artery disease (CAD) in subjects with a normal ankle-brachial index (ABI) in both legs. We measured UT and %MAP in 1953 subjects with a normal ABI. The optimal cutoff values of UT and %MAP derived from a receiver operating characteristic (ROC) curve to diagnose CAD were 148 ms and 40.4%, respectively. Multivariable analyses revealed that both UT ≥ 148 ms (odds ratio [OR], 2.72; p < 0.001) and %MAP ≥ 40.4% (OR, 1.28; p = 0.003) were significantly associated with CAD. When the subjects were divided into four groups according to the cutoff values of UT and %MAP, there was no significant difference in the risk of CAD between subjects with UT ≥ 148 ms and %MAP < 40.4% and those with UT ≥ 148 ms and %MAP ≥ 40.4% (OR, 1.45; p = 0.09). ROC curve analyses revealed that the area under the curve value of UT was significantly higher than that of %MAP (0.69 vs. 0.53, p < 0.001). The addition of UT to traditional risk factors significantly improved the diagnostic accuracy for CAD (0.82 to 0.84, p = 0.004), whereas the addition of %MAP to traditional risk factors did not improve the diagnostic accuracy for CAD (0.82 to 0.82, p = 0.84). UT is more useful than %MAP for identifying individuals with CAD among those with a normal ABI.

ROLE OF THE MACHINE LEARNING–DERIVED HYPOTENSION INDEX (HPI) TO CONTAIN INTRAOPERATIVE HYPOTENSION DURING TRANSCATHETER EDGE TO EDGE REPAIR PROCEDURES

Abstract Introduction Percutaneous endovascular valvular interventions can result in profound hemodynamic instability, elevated burden of intraoperative hypotension (IOH) and related postoperative complications: ischemic stroke, acute kidney injury and increased mortality. Machine learning(ML),a branch of Artificial intelligence (AI), can analyze large volumes of data, find associations and allowing predictive rather than reactive interventions. The Hypotension Prediction Index (HPI)a ML derived algorithm,provides a unitless number from 0 to 100, that increases accordingly to the risk of developing a hypotensive event (mean arterial pressure – MAP – &amp;lt; 65 mmHg for more than 1 minute) in the following minutes. The aim of this study is to describe IOH in patients undergoing percutaneous valve repair under general anesthesia treated according to an HPI–based hemodynamic guidance (fig.1). Methods Eligible adult patients undergoing transcatheter valve repair procedures (MitraclipTM, TriclipTM)were included in the study. When HPI value exceeded 85,a proactive individualized treatment protocol to prevent hypotension was provided according to the following modalities (fig. 2). Primary outcome measure was TWA–MAP (time weighted average mean arterial pressure)under the threshold of 65 mmHg. Secondary outcomes were number of patients with at least one hypotensive event, number of events per patient,depth and duration of hypotensive events and area under MAP threshold of 65 mmHg (AUT–MAP &amp;lt; 65). Results Twenty–five consecutive patients were prospectively enrolled and treated. During an average monitoring time per patient of 187 ± 31 minutes, the global burden of hypotension, measured as TWA–MAP &amp;lt; 65 mmHg, was 0.12 [0.02, 0.8] mmHg. Two thirds of the patients(16/25) experienced hypotensive events, with a median number of hypotensive events of 1 [0, 3.25] per patient and about 11% of the time spent &amp;lt; 65 mmHg. Each event lasted 4 [1.7, 8.6] minutes with a MAP of 59 [56, 62] mmHg, leading to a total AUT–MAP &amp;lt; 65 mmHg of 20.3 [3.5, 142.2] mmHg x minutes. The majority of hypotensive events occurred after induction of general anesthesia, while hypotension was rare during the procedure (fig. 3). Conclusions HPI algorithm provides accurate and continuous prediction of impending IOH before its occurrence. Machine learning models,as in the case of HPI, could facilitate the physicians to treat IOH which is a potentially modifiable risk factor for major postoperative complications.

No quadriceps muscle weakness following anterior quadratus lumborum block compared with placebo: a randomized, non-inferiority, blinded, volunteer trial

Background and aimsAnterior quadratus lumborum block is a truncal block, applied in close proximity to the lumbar plexus, potentially causing lower limb weakness. This trial aimed to evaluate whether a...

Lifestyle Intervention Improves Parasympathetic Activity in Hypertrophic Cardiomyopathy

Background A limited number of studies have investigated the effects of lifestyle interventions in hypertrophic cardiomyopathy (HCM). This study evaluated the effect of a novel lifestyle intervention incorporating physical activity (PA) and dietary nitrate supplementation on heart rate variability (HRV) and haemodynamic measures in HCM. Methods Twenty-eight individuals with HCM were randomised into either the intervention or control group. Frequency-domain HRV measures including low frequency power (LF), high frequency power (HF) and LF/HF were recorded at rest using bioimpedance. Non-invasive haemodynamic variables were recorded at rest using bioreactance. Participants in the intervention group consumed 6 mmol of nitrate daily (concentrated beetroot juice) and were instructed to increase and maintain daily PA by ≥ 2000 steps/day above baseline for 16 weeks. Control group participants retained their usual lifestyle and monitored daily step counts. Results There was a significant increase in post-intervention HF power (7.54 ± 2.14 vs 8.78 ± 1.60 ms2, P &lt; .01) and LF power (6.89 ± 2.33 vs 8.17 ± 1.55, P &lt; .01) in the intervention but not in the control group. Resting mean arterial blood pressure (MABP) in the intervention group significantly reduced at follow-up (108 ± 6 vs 102 ± 7 mmHg, P &lt; .01). Conclusions A novel lifestyle intervention including PA and dietary nitrate supplementation enhanced parasympathetic activity and resting MABP in HCM.

PREDICTION OF FLUID RESPONSIVENESS WITH CRYSTALLOID MINI-FLUID CHALLENGE IN CRITICALLY ILL PATIENTS

Background: The mini-fluid challenge test is a good predictor and has minimal limitations in determining fluid responsiveness in the critically ill. However, it primarily relies on colloid infusion. The availability of colloids may vary among hospitals in resource-limited countries, and they can be more expensive than crystalloid fluids. Objective: The study aimed to use crystalloids instead of colloids to predict fluid responsiveness. Methods: This study was conducted from August 2022 to February 2023 among patients with shock in the medical ICU to assess fluid responsiveness. Arterial and central venous catheters were used for the intravenous infusion and monitoring. Data were collected during two consecutive crystalloid mini-fluid challenges of 50 mL each in 1 minute, 100 mL in 2 minutes, and a standard fluid challenge of 300 mL over 15 minutes. The objective was to predict a stroke volume index (SVI) increase of &gt; 10%. Diagnostic accuracy was evaluated using the Receiver Operating Characteristic (ROC) curve, and hemodynamic variables in the positive fluid challenge group were compared for different volume expansions. Results: Twenty-nine patients (62% males; median age, 75 years) were included, with 42 fluid challenge test events. Septic shock was the primary condition in 83% of the cases. The 50 mL crystalloid mini-fluid challenge showed an accuracy of 80% with a sensitivity of 69% and specificity of 100% at the cutoff level of SVI &gt; 5%, Area Under ROC (AUROC)=0.79. In comparison, the 100 mL crystalloid mini-fluid challenge demonstrated an accuracy of 85% (sensitivity of 79% and specificity of 100%) at the cutoff level of SVI &gt; 10% (AUROC= 0.89). In the positive fluid challenge group, administration of crystalloids led to a significant increase in mean arterial pressure and SVI, while other parameters remained comparable. Conclusions: A mini-fluid challenge test with 100 mL crystalloids can predict fluid responsiveness in critically ill patients. The best cutoff level was a change in SVI &gt; 10% from baseline.

Periods of low renal perfusion pressure are associated with acute kidney injury following paediatric cardiac surgery.

Acute kidney injury is associated with worse outcomes after cardiac surgery. The haemodynamic goals to ameliorate kidney injury are not clear. Low post-operative renal perfusion pressure has been associated with acute kidney injury in adults. Inadequate oxygen delivery may also cause kidney injury. This study evaluates pressure and oximetric haemodynamics after paediatric cardiac surgery and their association with acute kidney injury. Retrospective case-control study at a children's hospital. Patients were < 6 months of age who underwent a Society of Thoracic Surgery-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery categories ≥ 3. Low renal perfusion pressure was time and depth below several tested thresholds. The primary outcome was serum creatine-defined acute kidney injury in the first 7 days. Sixty-six patients (median age 8 days) were included. Acute kidney injury occurred in 36%. The time and depth of renal perfusion pressure < 42 mmHg in the first 24 hours was greater in acute kidney injury patients (94 versus 35 mmHg*minutes of low renal perfusion pressure/hour, p = 0.008). In the multivariable model, renal perfusion pressure < 42 mmHg was associated with acute kidney injury (aOR: 2.07, 95%CI: 1.25-3.82, p = 0.009). Mean arterial pressure, central venous pressure, and measures of inadequate oxygen delivery were not associated with acute kidney injury. Periods of low renal perfusion pressure (<42 mmHg) in the first 24 post-operative hours are associated with acute kidney injury. Renal perfusion pressure is a potential modifiable target that may mitigate the impact of acute kidney injury after paediatric cardiac surgery.

AORTIC REGURGITATION INDEX IDENTIFIES SIGNIFICANT AORTIC REGURGITATION DURING IMPELLA SUPPORT FOR CARDIOGENIC SHOCK

Abstract Background Aortic regurgitation (AR) significantly hampers the unloading effect and the antegrade flow enhancement expected from the micro–axial flow pump Impella (Abiomed, Danvers). To date, no dedicated hemodynamic index is available to inform on the severity of AR during Impella support. Methods We included 100 patients receiving Impella support for CS with invasive hemodynamic assessment with pulmonary artery catheter (PAC). PAC measures were obtained 48 hours after Impella support initiation. AR grading was performed by either trans–thoracic or trans–esophageal echocardiography in the following strata: 0–none; 1–mild; 2–moderate; 3–moderate–severe; 4–severe. Study cohort was dichotomized according to AR severity≥2+. Several relevant hemodynamic indexes were validated against echocardiographic AR assessment to identify those mostly associated with significant AR (AR severity≥2+), including: AR index [ARI, calculated as (diastolic arterial pressure – pulmonary artery wedge pressure)/systolic arterial pressure, abbreviated in (DAP–PAWP)/SAP], diastolic pulse pressure (DPP, calculated as DAP–PAWP), MAP–adjuster ARI [ARIMAP calculated as (diastolic arterial pressure – pulmonary artery wedge pressure)/mean arterial pressure, abbreviated in (DAP–PAWP)/MAP)]. Results Significant AR (≥2+) was found in 31% patients. Patients with AR≥2+ had higher values of pulmonary artery wedge pressure (PAWP) after 48 hours from support initiation [15 (12, 21) vs 12 (10, 16) mmHg; p&amp;lt;0.021]. Several invasive hemodynamic indexes differentiated AR≥2+ vs AR&amp;lt;2 patients, including: ARI [0.42 (0.36, 0.51) vs 0.50 (0.44, 0.61); p&amp;lt;0.001], DPP [47 (37, 58) vs 57 (48.00, 68) mmHg; p=0.003] and ARIMAP [0.62 (0.54, 0.70) vs 0.70 (0.64, 0.75); p=0.005] (Figure 1). ARI demonstrated the strongest association and the greatest accuracy in identifying AR≥2+ (area under the curve 0.73; 95%CI: 0.61–0.85; p=0.002). The threshold of ARI 0.39 had excellent specificity (88.0%) and moderate sensitivity (62.9%), Figure 2. Conclusions The easy–to–use ARI metric [(DAP–PAWP)/SAP] accurately identifies patients with significant AR during Impella support, at the optimal cutoff of ARI 0.39. This index may be complementary to echocardiography in the assessment of AR during Impella support.

LONG–TERM FUNCTIONAL LIMITATIONS ON CARDIOPULMONARY EXERCISE TESTING IN A COHORT OF PATIENTS WITH EMOTIONS–TRIGGERED TAKOTSUBO SYNDROME

Abstract Background In patients with prior Takotsubo syndrome (TTS), long lasting functional cardiac limitations were described as compared with normal subjects. Emotions–triggered Takotsubo syndrome (E–TTS) has more favorable outcomes than TTS preceded by a physical trigger or by no identifiable factors. The aim of the present study was to assess long–term cardiac functional limitations in a cohort of asymptomatic E–TTS patients. Methods We enrolled n=39 asymptomatic patients with a diagnosis of E–TTS. Cardiopulmonary exercise tests (CPET) were performed at 30 [12–40] months median follow–up from the acute event. A cohort of n=39 individuals matched for age, sex, body mass index and comorbidities served as control. Results Despite recovery of left ventricular ejection fraction, patients with prior E–TTS had lower peak VO2 and percentage of predicted peak VO2 (17.8 ± 3.6 vs 22.5 ± 6.5; P &amp;lt; 0.001 and 75.2 ± 14.1 % vs 100.6 ± 17.1%, P &amp;lt;0.001), VO2 at anaerobic threshold (AT) (11.1 [10.1–12.9] vs 14.4 [12.5–18.7]; P &amp;lt;0.001), peak O2 pulse (9.7 ± 2.5 vs 13.1 ± 3.5; P &amp;lt;0.001) and higher VE/VCO2 slope (30.4 ± 3.7 vs 27.2 ± 3.5; P &amp;lt;0.001) compared with matched controls. We found no statistically significant differences in heart rate reserve (HRR), respiratory equivalent ratio (RER), mean blood pressure and peak PetCO2 between patients and controls. Conclusions Despite their overall favorable outcome, asymptomatic patients with E–TTS were found to have long–term subclinical functional cardiac impairments. CPET proved to be a useful tool in the long–term evaluation of E–TTS patients after recovery of LVEF. Further studies are needed to fully clarify the origin of the detected CPET abnormalities as well as their prognostic relevance in patience with recovered E–TTS.

Intensive Ambulance-Delivered Blood-Pressure Reduction in Hyperacute Stroke.

Treatment of acute stroke, before a distinction can be made between ischemic and hemorrhagic types, is challenging. Whether very early blood-pressure control in the ambulance improves outcomes among patients with undifferentiated acute stroke is uncertain. We randomly assigned patients with suspected acute stroke that caused a motor deficit and with elevated systolic blood pressure (≥150 mm Hg), who were assessed in the ambulance within 2 hours after the onset of symptoms, to receive immediate treatment to lower the systolic blood pressure (target range, 130 to 140 mm Hg) (intervention group) or usual blood-pressure management (usual-care group). The primary efficacy outcome was functional status as assessed by the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days after randomization. The primary safety outcome was any serious adverse event. A total of 2404 patients (mean age, 70 years) in China underwent randomization and provided consent for the trial: 1205 in the intervention group and 1199 in the usual-care group. The median time between symptom onset and randomization was 61 minutes (interquartile range, 41 to 93), and the mean blood pressure at randomization was 178/98 mm Hg. Stroke was subsequently confirmed by imaging in 2240 patients, of whom 1041 (46.5%) had a hemorrhagic stroke. At the time of patients' arrival at the hospital, the mean systolic blood pressure in the intervention group was 158 mm Hg, as compared with 170 mm Hg in the usual-care group. Overall, there was no difference in functional outcome between the two groups (common odds ratio, 1.00; 95% confidence interval [CI], 0.87 to 1.15), and the incidence of serious adverse events was similar in the two groups. Prehospital reduction of blood pressure was associated with a decrease in the odds of a poor functional outcome among patients with hemorrhagic stroke (common odds ratio, 0.75; 95% CI, 0.60 to 0.92) but an increase among patients with cerebral ischemia (common odds ratio, 1.30; 95% CI, 1.06 to 1.60). In this trial, prehospital blood-pressure reduction did not improve functional outcomes in a cohort of patients with undifferentiated acute stroke, of whom 46.5% subsequently received a diagnosis of hemorrhagic stroke. (Funded by the National Health and Medical Research Council of Australia and others; INTERACT4 ClinicalTrials.gov number, NCT03790800; Chinese Trial Registry number, ChiCTR1900020534.).