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.

Oscillations of Hemodynamic Parameters Induced by Negative Pressure Breathing in Healthy Humans.

INTRODUCTION: Negative pressure breathing is breathing with decreased pressure in the respiratory tract without lowering pressure acting on the torso. We lowered air pressure only during inspiration (NPBin). NPBin, used to increase venous return to the heart, is considered a countermeasure against redistribution of body fluids toward the head during spaceflight. We studied NPBin effects on circulation in healthy humans with an emphasis on NPBin-induced oscillations of hemodynamic parameters synchronous with breathing. We propose an approach to analyze the oscillations based on coherent averaging.METHODS: Eight men ages 24-42 yr participated in the NPBin and control series. During the series, to reproduce fluids shift observed under microgravity, subjects were supine and head down (-8°). Duration of NPBin was 20 min, rarefaction -20 cm H₂O. Hemodynamic parameters were measured by Finometer. Electrical impedance measurements were used to estimate changes in blood filling of cerebral vessels.RESULTS: Mean values of hemodynamic parameters virtually did not change under NPBin, but NPBin induced oscillations of the parameters synchronous with respiration. Peak-to-peak amplitude under NPBin were: mean arterial pressure, 4 ± 1 (mmHg); stroke volume, 7 ± 3 (mL); and heart rate, 4 ± 1 (bpm). Electrical impedance of the head increased during inspiration. The increase under NPBin was three times greater than under normal breathing.DISCUSSION: Analysis of oscillations gives more information than analysis of mean values. NPBin induces short-term decrease in left ventricle stroke volume and arterial blood pressure during each inspiration; the decrease is compensated by increase after inspiration. NPBin facilitates redistribution of body fluids away from the head.Semenov YS, Melnikov IS, Luzhnov PV, Dyachenko AI. Oscillations of hemodynamic parameters induced by negative pressure breathing in healthy humans. Aerosp Med Hum Perform. 2024; 95(6):297-304.

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.

Application of 3D printing surgical training models in the preoperative assessment of robot-assisted partial nephrectomy

BackgroundTo explore the application effect of 3D printing surgical training models in the preoperative assessment of robot-assisted partial nephrectomy.MethodsEighty patients who underwent robot-assisted partial nephrectomy surgery between January 2022 and December 2023 were selected and divided into two groups according to the chronological order. The control group (n = 40) received preoperative assessment with verbal and video education from January 2022 to December 2022, while the observation group (n = 40) received preoperative assessment with 3D printing surgical training models combined with verbal and video education from January 2023 to December 2023. The preoperative anxiety, information demand score, and surgical awareness were compared between the two groups. The physiological stress indicators, including interleukin-6 (IL-6), angiotensin II (AT II), adrenocorticotropic hormone (ACTH), cortisol (Cor), mean arterial pressure (MAP), and heart rate (HR), were also measured at different time points before and after surgery.They were 6:00 am on the day before surgery (T0), 6:00 am on the day of the operation (T1), 6:00 am on the first day after the operation (T2), and 6:00 am on the third day after the operation (T3).The preparation rate before surgery was compared between the two groups.ResultsThe anxiety and surgical information demand scores were lower in the observation group than in the control group before anesthesia induction, and the difference was statistically significant (P < 0.001). Both groups had lower scores before anesthesia induction than before preoperative assessment, and the difference was statistically significant (P < 0.05). The physiological stress indicators at T1 time points were lower in the observation group than in the control group, and the difference was statistically significant (P < 0.05). The overall means of the physiological stress indicators differed significantly between the two groups (P < 0.001). Compared with the T0 time point, the T1, T2, and T3 time points in both groups were significantly lower, and the difference was statistically significant (P < 0.05). The surgical awareness and preparation rate before surgery were higher in the observation group than in the control group, and the difference was statistically significant (P < 0.05).ConclusionThe preoperative assessment mode using 3D printing surgical training models combined with verbal and video education can effectively reduce the psychological and physiological stress responses of surgical patients, improve their surgical awareness, and enhance the preparation rate before surgery.

Machine Learning Algorithms Versus Classical Regression Models in Pre-Eclampsia Prediction: A Systematic Review.

Machine learning (ML) approaches are an emerging alternative for healthcare risk prediction. We aimed to synthesise the literature on ML and classical regression studies exploring potential prognostic factors and to compare prediction performance for pre-eclampsia. From 9382 studies retrieved, 82 were included. Sixty-six publications exclusively reported eighty-four classical regression models to predict variable timing of onset of pre-eclampsia. Another six publications reported purely ML algorithms, whilst another 10 publications reported ML algorithms and classical regression models in the same sample with 8 of 10 findings that ML algorithms outperformed classical regression models. The most frequent prognostic factors were age, pre-pregnancy body mass index, chronic medical conditions, parity, prior history of pre-eclampsia, mean arterial pressure, uterine artery pulsatility index, placental growth factor, and pregnancy-associated plasma protein A. Top performing ML algorithms were random forest (area under the curve (AUC) = 0.94, 95% confidence interval (CI) 0.91-0.96) and extreme gradient boosting (AUC = 0.92, 95% CI 0.90-0.94). The competing risk model had similar performance (AUC = 0.92, 95% CI 0.91-0.92) compared with a neural network. Calibration performance was not reported in the majority of publications. ML algorithms had better performance compared to classical regression models in pre-eclampsia prediction. Random forest and boosting-type algorithms had the best prediction performance. Further research should focus on comparing ML algorithms to classical regression models using the same samples and evaluation metrics to gain insight into their performance. External validation of ML algorithms is warranted to gain insights into their generalisability.

Chronic inhibition of angiotensin converting enzyme lowers blood pressure in spontaneously hypertensive rats by attenuation of sympathetic tone: The role of enhanced baroreflex sensitivity

Spontaneously hypertensive rats (SHR) are characterized by sympathetic hyperactivity and insufficient parasympathetic activity, and their high blood pressure (BP) can be lowered by long-term inhibition of the renin-angiotensin system. The aim of our study was to determine the influence of chronic inhibition of angiotensin converting enzyme (ACE) by captopril on cardiovascular regulation by the sympathetic and parasympathetic nervous system. Implanted radiotelemetric probes or arterial cannulas were used to measure mean arterial pressure (MAP), heart rate (HR), and arterial baroreflex in adult SHR and Wistar-Kyoto (WKY) rats under basal or stress conditions. MAP and the low-frequency component of systolic blood pressure variability (LF-SBPV, marker of sympathetic activity) were greater in SHR than in WKY rats. Under basal conditions chronic captopril treatment reduced both parameters more effectively in SHR, and the same was true during acute restraint stress. HR was similar in control rats of both strains, but WKY rats showed greater heart rate variability (HRV), indicating higher parasympathetic activity. Captopril administration increased HR in both strains, whereas HRV was decreased only in WKY. Chronic captopril treatment improved the impaired baroreflex-HR control in SHR by increasing the sensitivity but not the capacity of vagal arm of arterial baroreflex. Captopril treatment attenuated BP changes elicited by dimethylphenylpiperazinium (DMPP, agonist of nicotinic acetylcholine receptors), especially in SHR, indicating that sympathetic nerve transmission is facilitated by angiotensin II more in hypertensive than in normotensive animals. Thus, chronic ACE inhibition improves baroreflex sensitivity and lowers BP through both central and peripheral attenuation of sympathetic tone.

The Effect of an AI-Based, Autonomous, Digital Health Intervention Using Precise Lifestyle Guidance on Blood Pressure in Adults With Hypertension: Single-Arm Nonrandomized Trial.

Home blood pressure (BP) monitoring with lifestyle coaching is effective in managing hypertension and reducing cardiovascular risk. However, traditional manual lifestyle coaching models significantly limit availability due to high operating costs and personnel requirements. Furthermore, the lack of patient lifestyle monitoring and clinician time constraints can prevent personalized coaching on lifestyle modifications. This study assesses the effectiveness of a fully digital, autonomous, and artificial intelligence (AI)-based lifestyle coaching program on achieving BP control among adults with hypertension. Participants were enrolled in a single-arm nonrandomized trial in which they received a BP monitor and wearable activity tracker. Data were collected from these devices and a questionnaire mobile app, which were used to train personalized machine learning models that enabled precision lifestyle coaching delivered to participants via SMS text messaging and a mobile app. The primary outcomes included (1) the changes in systolic and diastolic BP from baseline to 12 and 24 weeks and (2) the percentage change of participants in the controlled, stage-1, and stage-2 hypertension categories from baseline to 12 and 24 weeks. Secondary outcomes included (1) the participant engagement rate as measured by data collection consistency and (2) the number of manual clinician outreaches. In total, 141 participants were monitored over 24 weeks. At 12 weeks, systolic and diastolic BP decreased by 5.6 mm Hg (95% CI -7.1 to -4.2; P<.001) and 3.8 mm Hg (95% CI -4.7 to -2.8; P<.001), respectively. Particularly, for participants starting with stage-2 hypertension, systolic and diastolic BP decreased by 9.6 mm Hg (95% CI -12.2 to -6.9; P<.001) and 5.7 mm Hg (95% CI -7.6 to -3.9; P<.001), respectively. At 24 weeks, systolic and diastolic BP decreased by 8.1 mm Hg (95% CI -10.1 to -6.1; P<.001) and 5.1 mm Hg (95% CI -6.2 to -3.9; P<.001), respectively. For participants starting with stage-2 hypertension, systolic and diastolic BP decreased by 14.2 mm Hg (95% CI -17.7 to -10.7; P<.001) and 8.1 mm Hg (95% CI -10.4 to -5.7; P<.001), respectively, at 24 weeks. The percentage of participants with controlled BP increased by 17.2% (22/128; P<.001) and 26.5% (27/102; P<.001) from baseline to 12 and 24 weeks, respectively. The percentage of participants with stage-2 hypertension decreased by 25% (32/128; P<.001) and 26.5% (27/102; P<.001) from baseline to 12 and 24 weeks, respectively. The average weekly participant engagement rate was 92% (SD 3.9%), and only 5.9% (6/102) of the participants required manual outreach over 24 weeks. The study demonstrates the potential of fully digital, autonomous, and AI-based lifestyle coaching to achieve meaningful BP improvements and high engagement for patients with hypertension while substantially reducing clinician workloads. ClinicalTrials.gov NCT06337734; https://clinicaltrials.gov/study/NCT06337734.

Comparative observation of the effectiveness and safety of remimazolam besylate versus dexmedetomidine in gastrointestinal surgery in obese patients

BACKGROUND Surgery for obese patients carries a higher risk of anesthesia complications compared with surgery for nonobese patients. Thus, a safe and effective anesthesia strategy is necessary to improve the medical experience of such patients and ensure their safety. AIM To compared the effectiveness and safety of remimazolam besylate versus dexmedetomidine (DEX) in gastrointestinal surgery in obese patients. METHODS The study cohort included 60 obese patients undergoing gastrointestinal surgery between July 2021 and April 2023, comprising 30 patients who received DEX intervention (control group) and 30 patients who received remimazolam besylate intervention (research group). Heart rate (HR), respiratory rate (RR), mean arterial pressure (MAP), blood oxygen saturation (SpO2), safety (nausea and vomiting, bradycardia, hypotension, and apnea), anesthesia and examination indices [induction time, anesthesia recovery time, and postanesthesia care unit (PACU) discharge time], sedation effect (Ramsay Sedation Scale), and postoperative pain visual analog scale were comparatively analyzed before anesthesia (T0), during anesthesia (T1), and after anesthesia (T2). RESULTS At T1, the research group showed significantly smaller changes in HR, RR, MAP, and SpO2 than the control group, with a significantly lower adverse reaction rate and shorter induction, anesthesia recovery, and PACU discharge times. Additionally, the intra- and postoperative Ramsay Sedation Scale scores were statistically higher in the research group than in the control group. CONCLUSION Remimazolam besylate was significantly more effective than DEX in gastrointestinal surgery in obese patients and had a higher safety profile and value in clinical promotion.

High-flow nasal cannula oxygen reduced hypoxemia in patients undergoing gastroscopy under general anesthesia at ultra-high altitude: a randomized controlled trial.

Hypoxemia can occur in people at ultra-high altitude (above 3500m) even at rest, and patients undergoing gastroscopy under general anesthesia have higher risk of hypoxemia. Supplementary oxygen via standard nasal cannula (SNC) is the standard of care for most patients who undergo gastroscopy under general anesthesia, which provides oxygen flow up to 15L/min. High-flow nasal cannula (HFNC) could deliver oxygen at a rate up to 60L/min, which is recommended by the American Society of Anesthesiologists Practice Guidelines. We speculated that the benefit with HFNC is more prominent in high-altitude areas, and aimed to compare the incidence of hypoxemia during gastroscopy under general anesthesia at ultra-high altitude with oxygen supply via either HFNC or SNC. The trial was registered at at Chinese Clinical Trial Registry (ChiCTR2100045513; date of registration on 18/04/2021). Adult patients undergoing gastroscopy with anesthesia (estimated duration of anesthesia at ≥ 15min) were randomized at a 1:1 ratio to receive HFNC oxygen or SNC oxygen. The primary outcome was hypoxemia (SpO2 < 90% for any duration). Secondary outcomes included severe hypoxemia (SpO2 < 75% for any duration or SpO2 < 90% but ≥ 75% for ≥ 60s) and hypotension, as defined by reduction of mean arterial blood pressure by ≥ 25% from the baseline. A total of 262 patients were enrolled: 129 in the HFNC group and 133 in the SNC group. All patients received the designated intervention. Student's t-test, Mann-Whitney U test and χ2 test were employed in the study. The rate of hypoxemia was 9.3% (12/129) in the HFNC group versus 36.8% (49/133) in the SNC group [risk ratio (95% confidence interval): 0.25(0.14-0.45); P < 0.001). The HFNC group also had lower rate of severe hypoxemia [0.0% (0/129) versus 11.3% (15/133); risk ratio (95% confidence interval): 0.03(0.00-0.55); P < 0.001, respectively]. The rate of hypotension did not differ between the 2 groups [22.5% (29/129) in HFNC group versus 21.1% (28/133) in SNC group; risk ratio (95% confidence interval): 1.07(0.67-1.69) ; P = 0.779]. HFNC oxygen reduced the incidence of hypoxemia during anesthesia in adult patients undergoing gastroscopy at ultra-high altitude.

Does Elevated Mean-Arterial Pressure Lead to Better Outcomes in Degenerative Cervical Myelopathy?- A Prospective, Pilot Randomized Control Trial.

Randomized Control Trial. DCM refers to compression of spinal cord either due to static/dynamic causes or commonly, a result of combination of both. Number of variables exist, which determine prognosis post-surgery. Role of intra-operative blood pressure has not been analyzed in depth in current literature. Elevating MAP post SCI is widely practiced and forms a recommendation of AANS/CNS Joint Committee Guidelines. This led us to investigate role played by elevated MAP during surgery for DCM, in order to optimize outcomes. This prospective randomized comparative pilot study was conducted at a tertiary care spine centre. 84 patients were randomly divided in two groups. Group 1 had intra-operative MAP in normal range. Group 2, had intra-operative BP 20 mmHg higher than preoperative average MAP with a variation of + 5mmHg. Outcomes were recorded at 3 months, 6 months and 1 year by mJOA, VAS and ASIA scale. Neurological improvement was documented in 19/30 (63.3%) patients of hypertensive group compared to 16/30 (53.3%) patients of normotensive group. Improvements in mJOA scores were better for hypertensive group during the 1-year follow-up. Improvement in VAS scores were comparable between two groups, but at 1-year follow-up the VAS score of hypertensive groups was significantly lower. MAP should be individualized according to preoperative average blood pressure assessment of patient. Keeping intraoperative MAP at higher level (preoperative MAP + 20mmHg) during surgery for DCM can result in better outcomes.

Changes of hemodynamic parameters in normal pregnant women and their relationship with maternal basic characteristics

Objective: To investigate the variation of reference ranges of hemodynamic parameters in normal pregnancy and their relation to maternal basic characteristics. Methods: A total of 598 healthy pregnant women who underwent regular prenatal examination at the Third Affiliated Hospital of Guangzhou Medical University from January to December 2023 were prospectively enrolled, and noninvasive hemodynamic monitors were used to detect changes in hemodynamic parameters of the pregnant women with the week of gestation, including cardiac output (CO), stroke volume (SV), thoracic fluid content (TFC), systemic vascular resistance (SVR), mean arterial pressure (MAP), and heart rate (HR). Relationships between hemodynamic parameters and maternal basic characteristics, including age, height, and weight, were analyzed using restricted cubic spline. Results: (1) CO (r=0.155, P<0.001), TFC (r=0.338, P<0.001), MAP (r=0.204, P<0.001), and HR (r=0.352, P<0.001) were positively correlated with the week of gestation, and SV was negatively correlated with the week of gestation (r=-0.158, P<0.001). There was no significant correlation between SVR and gestational age (r=-0.051, P=0.258). (2) CO exhibited a positive correlation with maternal height and weight (all P<0.001). The taller and heavier of pregnant women, the higher their CO. A linear relationship was observed between maternal weight and SV, MAP and HR (all P<0.01). As maternal weight increased, SV, MAP and HR showed an upward trend. Furthermore, there was an inverse association between maternal age and SVR (P<0.001). (3) There was a significant nonlinear association observed between TFC and body mass index during pregnancy (P<0.05). Additionally, a nonlinear relationship was found between SVR and MAP in relation to maternal age (all P<0.05). Notably, when the age exceeded 31 years old, there was an evident upward trend observed in both SVR and MAP. Conclusions: The hemodynamic parameters of normal pregnant women are influenced by their height, body weight, and age. It is advisable to maintain a reasonable weight during pregnancy and give birth at an appropriate age.

Erector spinae plane block for pain management in blunt chest trauma in military prehospital medicine, an interventional study

ABSTRACT Background Erector spinae plane block (ESPB) was presented in previous studies as a simple and safe technique with an excellent analgesic profile and improvement in respiratory function in multiple rib fractures. The purpose of this study was to investigate the efficiency of performing ESPB in the primary care unit for pain alleviation for individuals with blunt chest traumas. Methods This prospective interventional work was performed on 54 patients ranging in age from 20 to 50 years old, both sexes, American society of anesthesiology class I and II diagnosed with multiple rib fracture following blunt chest trauma. ESPB were performed using 20 mL of 0.25% levo-bupivacaine. Results The median (IQR) numeric rate scale was 9 (8–9) before block application and was significantly reduced to 1 (0–1) till it was 0 (0–1) in the 12th hour. After 24th hour, the median pain score was 2 (1–2), (p < 0.00). The mean arterial blood pressure and heart rate have significantly decreased following the block. Regarding complications of morphine, two patients only experienced mild vomiting. There were no other complications (local anesthetic toxicity, hematoma formation and pneumothorax). Conclusion Prehospital administration of ESPB for blunt chest trauma improved the pain scores, decreased the opioid administration without negative consequences on the hemodynamic state or occurrence of complications among participants.

Usefulness of risk assessment tools in predicting hemodynamic outcome after balloon pulmonary angioplasty: a comparative analysis

ABSTRACT Objectives Several parameters of widely used risk assessment tools for pulmonary arterial hypertension (PAH) have been linked to hemodynamic outcomes of balloon pulmonary angioplasty (BPA). Therefore, we aimed to determine whether these risk assessment tools could be used to predict hemodynamic outcomes following BPA. Methods In this retrospective study, we included 139 patients with chronic thromboembolic pulmonary hypertension who had undergone BPA. We compared the accuracies of seven well-validated risk assessment tools for predicting hemodynamic outcomes following BPA. A favorable hemodynamic outcome was defined as a mean pulmonary arterial pressure <30 mmHg at follow-up. Results The baseline risk profiles varied significantly among the risk assessment tools. The US Registry to Evaluate Early and Long-Term PAH Disease Management risk scales and the French risk assessment tools rated most patients as high-risk, while the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA) series and laboratory examination-based risk scales categorized most patients as having intermediate-risk. COMPERA 2.0 (4-strata) exhibited the highest predictive power among all risk stratifications. Noninvasive risk stratification (COMPERA 2.0 [3-strata]) showed a comparable predictive ability to that of invasive risk stratification (COMPERA 1.0) (area under the curve 0.649 vs. 0.648). Moreover, incorporating diffusing capacity of the lungs for carbon monoxide and tricuspid regurgitation velocity into COMPERA 2.0 (4-strata) further enhanced its predictive power (net reclassification index 0.153, 95% confidence interval 0.009–0.298, p = 0.038). Additionally, this refined COMPERA version had a high calibration accuracy (slope 0.96). Conclusion Although the risk strata distribution varied among different risk assessment tools, the proportion of patients achieving favorable hemodynamics decreased with the escalation of risk stratification in most models. The well-validated risk assessment tools for PAH could also predict hemodynamic outcomes following BPA, and the refined COMPERA 2.0 model exhibited the highest predictive ability among these. Applying risk assessment tools before BPA can facilitate early identification of patients in need of closer monitoring and more intensive interventions, contributing to a better prognosis after BPA.

Effect of acute intranasal insulin administration on muscle sympathetic nerve activity in healthy young adults.

Systemic insulin increases muscle sympathetic nerve activity (MSNA) via both central actions within the brainstem and peripheral activation of the arterial baroreflex. Augmented MSNA during hyperinsulinemia likely restrains peripheral vasodilation and contributes to the maintenance of blood pressure (BP). However, in the absence of insulin action within the peripheral vasculature, whether central insulin stimulation increases MSNA and influences peripheral hemodynamics in humans remains unknown. Herein, we hypothesized intranasal insulin administration would increase MSNA and BP in healthy young adults. Participants were assigned to time control [(TC), n=13 (5F/8M), 28±1 yrs] or 160 IU of intranasal insulin administered over five min [n=15 (5F/10M), 26±2 yrs]; five (1F/4M) participants completed both conditions. MSNA (fibular microneurography), BP (finger photoplethysmography), and leg blood flow (LBF, femoral Doppler ultrasound) were assessed at baseline, 15, and 30 minutes following insulin administration. Leg vascular conductance (LVC = [LBF ÷ mean BP] x 100) was calculated. Venous insulin and glucose concentrations remained unchanged throughout (p>0.05). Following intranasal insulin administration, MSNA (burst frequency; baseline = 100%; minute 15: 121±8%; minute 30: 118±6%; p=0.009, n=7) and mean BP (baseline = 100%; minute 15: 103±1%; minute 30: 102±1%; p=0.003) increased, while LVC decreased (baseline = 100%; minute 15: 93±3%; minute 30: 99±3%; p=0.03). In contrast, MSNA, mean BP, and LVC were unchanged in TC participants (p>0.05). We provide the first evidence that intranasal insulin administration in healthy young adults acutely increases MSNA and BP and decreases LVC. These results enhance mechanistic understanding of the sympathetic and peripheral hemodynamic response to insulin.

Autonomous precision resuscitation during ground and air transport of an animal hemorrhagic shock model

We tested the ability of a physiologically driven minimally invasive closed-loop algorithm, called Resuscitation based on Functional Hemodynamic Monitoring (ReFit), to stabilize for up to 3 h a porcine model of noncompressible hemorrhage induced by severe liver injury and do so during both ground and air transport. Twelve animals were resuscitated using ReFit to drive fluid and vasopressor infusion to a mean arterial pressure (MAP) > 60 mmHg and heart rate < 110 min−1 30 min after MAP < 40 mmHg following liver injury. ReFit was initially validated in 8 animals in the laboratory, then in 4 animals during air (23nm and 35nm) and ground (9 mi) to air (9.5nm and 83m) transport returning to the laboratory. The ReFit algorithm kept all animals stable for ~ 3 h. Thus, ReFit algorithm can diagnose and treat ongoing hemorrhagic shock independent to the site of care or during transport. These results have implications for treatment of critically ill patients in remote, austere and contested environments and during transport to a higher level of care.

Blood pressure reduction with empagliflozin in Japanese patients with type 2 diabetes and cardiovascular diseases: a post-hoc sub-analysis of the placebo-controlled randomized EMBLEM trial.

Detailed effect of sodium-glucose cotransporter 2 inhibitors on blood pressure (BP) in Japanese patients with type 2 diabetes (T2D) at a high risk of cardiovascular disease (CVD) is not fully understood. In this post-hoc sub-analysis of placebo-controlled randomized EMBLEM trial for Japanese patients with T2D and CVD, 105 participants (empagliflozin N = 52, placebo N = 53) were included, and office systolic/diastolic BPs and mean arterial pressure (MAP) over 24 weeks were estimated using mixed-effects models for repeated measures. Empagliflozin therapy, compared to placebo, reduced systolic/diastolic BPs (mean group difference in change from baseline to week 24; -5.9 [95% confidence interval (CI), -10.4 to -1.4] mmHg/-2.9 [95% CI, -6.2 to 0.4] mmHg) and MAP ( - 3.8 [95% CI, -7.0 to -0.7] mmHg). The systolic BP reduction was almost consistent across differing background clinical characteristics and usage status of anti-hypertensive medications.