Lower Mean Arterial Pressure Research Articles

The effect of a neonatal sleep intervention on maternal postpartum hypertension: a randomized trial

In nonpregnant adults, poor sleep is associated with higher blood pressure. Poor sleep is common in the postpartum period and is often attributed to infant caretaking needs. However, its effects on cardiovascular health in individuals with a hypertensive disorder of pregnancy are unknown. This study aimed to determine the effect of a neonatal sleep intervention on maternal postpartum blood pressure in individuals with a hypertensive disorder of pregnancy. In this single-institution pilot randomized controlled trial from July 2021 to March 2022, 110 individuals with a hypertensive disorder of pregnancy were randomized to receive a neonatal sleep intervention (SNOO responsive bassinet) plus usual care of safe sleep education (n=54) or usual care alone (n=56). Remote follow-up visits were conducted at 1 week, 6 weeks, and 4 months after delivery and involved blood pressure and weights, sleep and mood questionnaires, and self-reported infant and maternal sleep logs. Based on institutional data, the sample size had 80% power to detect a 4.5-mm Hg difference in the primary outcome of mean arterial pressure at 6 weeks after delivery. Baseline characteristics were similar between the arms. At 1 week after delivery, the intervention arm had lower mean arterial pressure and less antihypertensive medication use than the control arm (99±10 vs 103±7 mm Hg [P=.04] and 23% vs 35% [P=.15], respectively). At 6 weeks after delivery, mean arterial pressure was similar between arms (93±8 vs 94±8 mm Hg; P=.54), but there was a lower rate of antihypertensive use in the intervention arm (15% vs 26%; P=.19). Scores from maternal sleep and mood questionnaires at 6 weeks after delivery and self-reported infant and maternal sleep duration at 6 weeks and 4 months after delivery were similar between arms (P>.05). The SNOO responsive bassinet as a neonatal sleep intervention did not result in improved mean arterial pressure at 6 weeks after delivery after hypertensive disorders of pregnancy.

Encouraging Regular Aortic Valve Opening for EVAHEART 2 LVAD Support Using Virtual Patient Hemodynamic Speed Modulation Analysis.

This study focuses on investigating the EVAHEART 2 left ventricular assist device (LVAD) toward designing optimal pump speed modulation (PSM) algorithms for encouraging aortic valve (AV) flow. A custom-designed virtual patient hemodynamic model incorporating the EVAHEART 2 pressure-flow curves, cardiac chambers, and the systemic and pulmonary circulations was developed and used in this study. Several PSM waveforms were tested to evaluate their influence on the mean arterial pressure (MAP), cardiac output (CO), and AV flow for representative heart failure patients. Baseline speeds were varied from 1,600 to 2,000 rpm. For each baseline speed, the following parameters were analyzed: 1) PSM ratio (reduced speed/baseline speed), 2) PSM duration (3-7 seconds), 3) native ventricle contractility, and 4) patient MAP of 70 and 80 mm Hg. More than 2,000 rpm virtual patient scenarios were explored. A lower baseline speed (1,600 and 1,700 rpm) produced more opportunities for AV opening and more AV flow. Higher baseline speeds (1,800 and 2,000 rpm) had lower or nonexistent AV flow. When analyzing PSM ratios, a larger reduction in speed (25%) over a longer PSM (5+ seconds) duration produced the most AV flow. Lower patient MAP and increased native ventricle contractility also contributed to improving AV opening frequency and flow. This study of the EVAHEART 2 LVAD is the first to focus on leveraging PSM to enhance pulsatility and encourage AV flow. Increased AV opening frequency can benefit aortic root hemodynamics, thereby improving patient outcomes.

The effect of higher or lower mean arterial pressure on kidney function after cardiac arrest: a post hoc analysis of the COMACARE and NEUROPROTECT trials

BackgroundWe aimed to study the incidence of acute kidney injury (AKI) in out-of-hospital cardiac arrest (OHCA) patients treated according to low-normal or high-normal mean arterial pressure (MAP) targets.MethodsA post hoc analysis of the COMACARE (NCT02698917) and Neuroprotect (NCT02541591) trials that randomized patients to lower or higher targets for the first 36 h of intensive care. Kidney function was defined using the Kidney Disease Improving Global Outcome (KDIGO) classification. We used Cox regression analysis to identify factors associated with AKI after OHCA.ResultsA total of 227 patients were included: 115 in the high-normal MAP group and 112 in the low-normal MAP group. Eighty-six (38%) patients developed AKI during the first five days; 40 in the high-normal MAP group and 46 in the low-normal MAP group (p = 0.51). The median creatinine and daily urine output were 85 μmol/l and 1730 mL/day in the high-normal MAP group and 87 μmol/l and 1560 mL/day in the low-normal MAP group. In a Cox regression model, independent AKI predictors were no bystander cardiopulmonary resuscitation (p < 0.01), non-shockable rhythm (p < 0.01), chronic hypertension (p = 0.03), and time to the return of spontaneous circulation (p < 0.01), whereas MAP target was not an independent predictor (p = 0.29).ConclusionAny AKI occurred in four out of ten OHCA patients. We found no difference in the incidence of AKI between the patients treated with lower and those treated with higher MAP after CA. Higher age, non-shockable initial rhythm, and longer time to ROSC were associated with shorter time to AKI.Clinical trial registration: COMACARE (NCT02698917), NEUROPROTECT (NCT02541591).

Incidence and predictors of intraoperative hypotension during transurethral bladder tumor resection with oral 5-aminolevulinic acid.

To analyze the incidence and risk factors of intraoperative hypotension related to photodynamic diagnosis-assisted transurethral resection of bladder tumor (PDD-TURBT) with oral 5-aminolevulinic acid (5-ALA). We retrospectively analyzed 487 patients with bladder tumors who underwent PDD-TURBT (n = 184) or conventional TURBT (conv-TURBT) (n = 303) between 2018 and 2021. Intraoperative hypotension was defined as hypotension requiring vasopressors during TURBT, and its incidence was compared between the two groups. Potential risk factors of intraoperative hypotension, including preoperative change in mean arterial pressure (MAP), were further investigated in patients receiving PDD-TURBT. The median age was 72 years, 392 patients (81%) were male, and 203 (42%) had hypertension. TURBT was performed under general and spinal anesthesia in 76 (16%) and 411 (84%) patients, respectively. The incidence of intraoperative hypotension was significantly higher in PDD-TURBT compared to conv-TURBT (43% vs. 17%, respectively). The median change in MAP until the induction of anesthesia was +6.5 mmHg (range: -29.0 to +46.3) in the PDD-TURBT group and +14.7 mmHg (range: -35.3 to +67.7) in the conv-TURBT group, showing a significantly smaller increase in the PDD-TURBT group (p < 0.001). In the multivariable analysis for PDD-TURBT patients, advanced age, general anesthesia, and lower MAP change (<+6.5 mmHg) until anesthesia induction were significantly associated with intraoperative hypotension (p = 0.0104, <0.001, and <0.001, respectively). Intraoperative hypotension occurred more frequently in patients who underwent PDD-TURBT than in those who underwent conv-TURBT. Using oral 5-ALA decreases preoperative blood pressure elevation and may be responsible for intraoperative hypotension.

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.

The effect of the gender on the risk of long-covid and cardiovascular complications in healthy patients without comorbidities- data from the polish long-COVID cardiovascular (PoLoCOV-CVD) study

Abstract Background The long-Covid (LC) is now a great challenge for the healthcare systems worldwide. There are still inconsistent data on gender as an independent risk factor of LC complications. PURPOSE We aimed to assess the age-independent differences between males and females without comorbidities on the risk of long Covid (LC) and LC cardiovascular complications. Methods Patient’s information, course of the disease, post-COVID-19 symptoms were collected in men and women at least 12 weeks and one year after the COVID-19 recovery. ECG, 24-hour ECG monitoring; 24-hour ambulatory blood pressure monitoring (ABPM), echocardiography, and selected biochemical tests were performed. LC was diagnosed based on the World Health Organization (WHO) definition. To reduce the impact of confounders i.e. body mass index (BMI) and age on the results of study, the Nearest Neighbour (NN) propensity score matching (PSM) method was used. Results Out of 2192 women and 1237 men after COVID-19 we identified 783 women (mean age 45) and 455 men (mean age 44). After elimination of patients with comorbidities and matching the PSM analyses reduced the total number of cases into 733 cases (i.e. 395 women and 378 men). The further analyses showed that males required more often the hospitalisation due to of pneumonia (12.5 vs 5.5%; p=0.0003) during the acute phase of COVID-19 compared to females, however there was no difference regarding the Intensive Care Unit (ICU) stay. Both after 3 months and after a one year women reported more long-COVID symptoms than men (4 vs 3, p&amp;lt;0.0001 and 2 vs 0, p=0.004; respectively). After one year follow-up women suffered from long-COVID more often than men (63 vs 59% p=0.0001). The symptoms that significantly differed women and were fatigue (32 in women vs 24 % in men; p=0.007) and hair lost (6,5 vs 0,26%; p&amp;lt;0.0001). Females during LC had lower mean arterial pressure (MAP) [ 88 (82-94) mmHg versus (vs) 94 (89-99); p&amp;lt;0.0001] and lower pulse pressure (PP) [46 (41-520 mmHg vs 51(47-56); p&amp;lt;0.0001] in 24 -hours ABPM compared to males one year after COVID-19 (Figure 1). Men had more often one of the ECG abnormalities: HR &amp;gt;100/min, QRS &amp;gt;=120ms, ST-T changes, T inversion, arrhythmia, QRS fragmentation [29 vs 22%; p=0.02] (Figure 1). There were no significant differences in myocardial damage assessed in late gadolinium enhancement cardiac magnetic resonance (CMR) between sex. There were no differences regarding sport activity, the level of stress and fatigue as well as alcohol drinking and smoking between men and women at the same age and BMI. One year after COVID-19, 82% of women and 78% of men reported having completed a course of vaccination against COVID-19 (p&amp;gt;0.05). Conclusion One-year after Covid-19 recovery women without comorbidities more often suffered from long-COVID than men regardless of the age. Females after COVID-19 had lower mean arterial pressure and pulse pressure in 24 -hours ABPM and less ECG abnormalities than males.

Cardiogenic shock complicating acute myocardial infarction; mechanical circulatory support use in the Netherlands

Abstract Introduction Mortality rates in cardiogenic shock complicating acute myocardial infarction (AMICS) linger around 40-50%. Despite the lack of evidence, the use of mechanical circulatory support (MCS) in this population is increasing rapidly worldwide. Purpose This study aimed to give insights in MCS use in the Netherlands and to assess how the use of MCS is associated with mortality. Methods Data from all patients undergoing percutaneous coronary intervention (PCI) in the Netherlands is prospectively registered in the Netherlands Heart Registration (NHR) database. On top of the obligatory registration, additional data were retrieved for all patients with cardiogenic shock undergoing PCI between 2017 and 2021 in 14 Dutch hospitals. The additional variables included the use of different types of MCS. Multivariate logistic regression was used to test the association between MCS and mortality in adjustment for confounders. Results In total, we included 2328 patients, with a mean age of 66.4 ± 12.3 years and of whom 72.9% were male. Of all patients, 23.6% received a form of MCS (11.5% an IABP, 4.5% an Impella, 3.1% VA-ECMO, 4.2% a combination of devices and 0.3% other). Compared to patients who did not receive MCS, MCS supported patients were younger (64.2 vs. 67.1 years, p &amp;lt;0.001), presented after an out-of-hospital cardiac arrest (OHCA) less often (33.3% vs. 39.9%, p = 0.008), had complaints for over three hours more often (50.3% vs. 38.8%, p = 0.001) and had a lower mean arterial pressure (MAP) (74.9 vs. 78.6 mmHg, p &amp;lt;0.005) and higher heartrate (88.2 vs 81.8 beats per minute, p &amp;lt;0.001) at admission. Also, mean admission lactate (6.4 vs. 5.2, p &amp;lt;0.001), glucose (13.4 vs. 11.8, p &amp;lt;0.001) and creatinine levels (104 vs. 99, p &amp;lt;0.001) were higher in MCS-receiving patients. Additionally, patients who received MCS support more often suffered from multivessel disease (68.7% vs. 58.4%, p &amp;lt;0.001) and chronic total occlusions (CTO) (3.5% vs. 1.9%, p = 0.027) and were treated with inotropes prior to PCI more often (54.9% vs. 46.2%, p &amp;lt;0.001). The overall 30-day mortality was higher in the MCS cohort than in the no-MCS cohort, namely 54.4% vs. 34.3% (OR = 2.28, 95%CI = 1.88-2.78). In adjustment for age, OHCA, complaints duration, admission MAP, heartrate, lactate, glucose and creatinine, the presence of multivessel disease and CTO and inotrope use before PCI, MCS was independently associated with 30-day mortality (adjusted OR = 2.23, 95% CI = 1.54-3.23). Conclusion MCS was deployed in 23.6% of the patients in this cohort. Despite the results of the IABP-SHOCK II trial, IABP was the most frequently used device. In this cohort, MCS was independently associated with 30-day mortality. However, residual confounding is probably present. Besides randomised controlled trials guiding clinical decision making regarding MCS use and timing, future research should also focus on investigating barriers to implement the results of previous trials.KM-curve of unadjusted survival

High versus low mean arterial pressure targets after out-of-hospital cardiac arrest: a meta-analysis of randomized controlled trials

Abstract Background Out-of-hospital cardiac arrest (OHCA) is a significant healthcare burden, with an average global incidence of 55 per 100,000 person-years among adults. OHCA patients require blood pressure support to maintain effective mean arterial pressure (MAP) for cerebral reperfusion, which is usually achieved by intravascular fluids and vasopressors in the intensive care unit (ICU). Targeting a specific MAP has been evaluated as a treatment strategy after OHCA; however, the current evidence lacks clear guidelines regarding the optimal MAP target after OHCA. Purpose We aim to evaluate the efficacy of targeting a high MAP (&amp;gt;70 mmHg) versus a low MAP target (&amp;lt; 65 mmHg) after OHCA resuscitation. Methods We conducted a systematic review and meta-analysis synthesizing randomized controlled trials (RCTs), which were retrieved by systematically searching: PubMed, EMBASE, Web of Science, SCOPUS, and Cochrane through January 18th, 2023. Continuous and dichotomous outcomes were pooled using mean difference (MD) and risk ratio (RR) along with confidence interval (CI), using Revman V. 5.4 software. Our review protocol was prospectively published on PROSPERO with ID: CRD42023395333. Results Four RCTs with a total of 1070 patients (531 in the high MAP target group and 534 in the low MAP target group) were included in our analysis. High MAP target was significantly associated with decreased ICU length of stay (MD: -0.78 with a 95 CI [-1.54, -0.02], P= .04) and mechanical ventilation duration (MD: -0.91 with a 95 CI of [-1.51, -0.31], P= .003). However, There was no difference between targeting a high MAP versus low MAP regarding all-cause mortality (RR: 1.07 with a 95% CI [0.91, 1.27], P= 0.4), favorable neurological recovery (cerebral categories scale (CPC) ≤ 2) (RR: 1.02 with a 95% CI [0.93, 1.13], P= 0.68), and neuron-specific enolase (NSE) at 48 hours (MD: 0.54 with 95% CI [-1.67, 2.75], P = 0.63), the incidence of adverse events, including any bleeding (RR: 0.89 with a 95% CI [0.69, 1.36], P= 0.39); arrhythmia (RR: 0.91 with a 95% CI [0.46, 1.82], P= 0.79), or acute kidney injury (RR: 0.80 with a 95% CI [0.36, 1.76] and P = 0.58). Conclusion In patients with OHCA who have been resuscitated, targeting a higher MAP significantly reduced the ICU length of stay and mechanical ventilation, implying potential clinical benefit with an acceptable safety margin. However, there was no difference between targeting a high MAP versus a low MAP regarding all-cause mortality, favorable neurological recovery, and NSE. Therefore, further RCTs are still warranted to elucidate the potential clinical benefit of targeting a high MAP after OHCA before endorsement in clinical practice.Figure 1Figure 2

Surgical Apgar scores predict complications after emergency general surgery laparotomy.

The Surgical Apgar Score (SAS) is a 10-point validated score comprised of three intraoperative variables (blood loss, lowest heart rate, and lowest mean arterial pressure). Lower scores are worse and predict major postoperative complications. The SAS has not been applied in emergency general surgery (EGS) but may help guide postoperative disposition. We hypothesize that SAS can predict complications in EGS patients undergoing a laparotomy. We performed a retrospective review of adult patients at a single, quaternary care center who underwent an exploratory laparotomy for EGS conditions within 6 hours of surgical consultation from 2015 to 2019. Patients were grouped by whether they experienced a postoperative complication (systemic, surgical, and/or death). Multivariable regression was performed to predict complications, accounting for SAS and other statistically significant variables between groups. Using this model, predicted probabilities of a complication were generated for each SAS. The cohort comprised 482 patients: 32.8% (n = 158) experienced a complication, while 67.2% (n = 324) did not. Patients with complications were older, frailer, more often male, had worse SAS (6 vs. 7, p < 0.0001) and American Society of Anesthesiologists scores, and higher rates of perforated hollow viscus ( p = 0.0003) and open abdomens ( p < 0.0001). On multivariable regression, an increasing SAS independently predicted less complications (adjusted odds ratio, 0.85; 95% confidence interval, 0.75-0.96; p = 0.009). An SAS ≤4 was associated with a 49.2% predicted chance of complications, greater rates of septic shock (9.7% vs. 3%, p = 0.01), respiratory failure (20.5% vs. 10.8%, p = 0.02), and death (24.1% vs. 7.5%, p < 0.0001). An SAS ≤ 4 did not correlate with surgical complications ( p = 0.1). The SAS accurately predicts postoperative complications in EGS patients undergoing urgent laparotomy, with an SAS ≤ 4 identifying patients at risk for septic shock, respiratory failure, and mortality. This tool can aid in rapidly determining postoperative disposition and resource allocation. Therapeutic/Care Management; Level IV.

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.

Association between postoperative hypotension and acute kidney injury after noncardiac surgery: a historical cohort analysis.

The extent to which postoperative hypotension contributes to renal injury remains unclear, much less what the harm thresholds might be. We therefore tested the primary hypothesis that there is an absolute hypotensive arterial pressure threshold for acute kidney injury during the initial seven days after noncardiac surgery. We conducted a single-centre historical cohort analysis of adults who had noncardiac surgery and had creatinine recorded preoperatively and postoperatively. Our exposure was the lowest postoperative mean arterial pressure, defined as the average of the three lowest postoperative pressure measurements. Our primary analysis was the association between the lowest mean arterial pressure and acute kidney injury, defined according to Kidney Disease: Improving Global Outcomes initiative criteria. Our analysis was adjusted for potentially relevant confounding factors including intraoperative hypotension. Among 64,349 patients analyzed, 2,812 (4.4%) patients had postoperative acute kidney injury. Each 5-mmHg decrease in the lowest mean arterial pressure was associated with a 28% (97.5% confidence interval [CI], 23 to 32; P < 0.001) increase in the odds of acute kidney injury for lowest mean arterial pressures <80mmHg. Higher lowest pressures were not associated with acute kidney injury (odds ratio, 1.08; 97.5% CI, 0.99 to 1.17; P = 0.04) for each 5-mmHg decrease in the lowest mean arterial pressure. Postoperative hypotension, defined as the lowest postoperative mean arterial pressure <80mmHg, was associated with acute kidney injury after noncardiac surgery. A prospective trial will be required to determine whether the observed association is causal and thus amenable to modification.

The Molecular Size of Bioengineered Oxygen Carriers Determines Tissue Oxygenation in a Hypercholesterolemia Guinea Pig Model of Hemorrhagic Shock and Resuscitation.

Polymerized human hemoglobin (PolyhHb) has shown promise in preclinical hemorrhagic shock settings. Different synthetic and purification schemes can control the size of PolyhHbs, yet research is lacking on the impact of polymerized hemoglobin size on tissue oxygenation following hemorrhage and resuscitation in specialized animal models that challenge their resuscitative capabilities. Pre-existing conditions that compromise the vasculature and end organs, such as the liver, may limit the effectiveness of resuscitation and exacerbate the toxicity of these molecules, which is an important but minimally explored therapeutic dimension. In this study, we compared the effective oxygen delivery of intermediate molecular weight PolyhHb (PolyhHb-B3; 500-750 kDa) to high molecular weight PolyhHb (PolyhHb-B4; 750 kDa-0.2 μm) for resuscitative effectiveness in guinea pig models subjected to hemorrhagic shock. We evaluated how the size of PolyhHb impacts hemodynamics and tissue oxygenation in normal guinea pigs and guinea pigs on an atherogenic diet. We observed that while PolyhHb-B3 and -B4 equivalently restore hemodynamic parameters of normal-dieted guinea pigs, high-fat-dieted guinea pigs resuscitated with PolyhHb-B4 have lower mean arterial pressures, impaired tissue oxygenation, and higher plasma lactate levels than those receiving PolyhHb-B3. We characterized the plasma of these animals following resuscitation and found that despite similar oxygen delivery kinetics, circulating PolyhHb-B3 and -B4 demonstrated a size-dependent increase in the plasma viscosity, consistent with impaired perfusion in the PolyhHb-B4 transfusion group. We conclude that intermediate-sized PolyhHbs (such as -B3) are ideal for further research given the effective resuscitation of hemorrhagic shock based on tissue oxygenation in hypercholesterolemic guinea pigs.

Establishment and validation of a prognosis nomogram for MIMIC-III patients with liver cirrhosis complicated with hepatic encephalopathy

IntroduceThe purpose of this study was to establish a comprehensive prognosis nomogram for patients with liver cirrhosis complicated with hepatic encephalopathy (HE) in the intensive care unit (ICU) and to evaluate the predictive value of the nomogram.MethodThis study analyzed 620 patients with liver cirrhosis complicated with HE from the Medical Information Mart for Intensive Care III(MIMIC-III) database. The patients were randomly divided into two groups in a 7-to-3 ratio to form a training cohort (n = 434) and a validation cohort (n = 176). Cox regression analyses were used to identify associated risk variables. Based on the multivariate Cox regression model results, a nomogram was established using associated risk predictor variables to predict the 90-day survival rate of patients with cirrhosis complicated with HE. The new model was compared with the Sequential organ failure assessment (SOFA) scoring model in terms of the concordance index (C-index), the area under the curve (AUC) of receiver operating characteristic (ROC) analysis, the net reclassification improvement (NRI), the integrated discrimination improvement (IDI), calibration curve, and decision curve analysis (DCA).ResultsThis study showed that older age, higher mean heart rate, lower mean arterial pressure, lower mean temperature, higher SOFA score, higher RDW, and the use of albumin were risk factors for the prognosis of patients with liver cirrhosis complicated with HE. The use of proton pump inhibitors (PPI) was a protective factor. The performance of the nomogram was evaluated using the C-index, AUC, IDI value, NRI value, and DCA curve, showing that the nomogram was superior to that of the SOFA model alone. Calibration curve results showed that the nomogram had excellent calibration capability. The decision curve analysis confirmed the good clinical application ability of the nomogram.ConclusionThis study is the first study of the 90-day survival rate prediction of cirrhotic patients with HE in ICU through the data of the MIMIC-III database. It is confirmed that the eight-factor nomogram has good efficiency in predicting the 90-day survival rate of patients.

Influence of perioperative blood pressure regulation on postoperative delirium in patients undergoing head and neck free flap reconstruction

BackgroundPostoperative delirium (POD) is a serious complication in patients undergoing microvascular head and neck reconstruction. Whether intraoperative and postoperative blood pressure regulation are risk factors for POD remains unclear. This study aimed to highlight the relationships between intraoperative and postoperative blood pressure regulation and POD in microvascular head and neck reconstruction.MethodsData from 433 patients who underwent microvascular head and neck reconstruction at our department of oral and maxillofacial surgery between 2011 and 2019 were retrospectively analyzed. The 55 patients with POD were matched with 55 patients without POD in terms of tracheotomy, flap type, and flap location, and the intraoperative and postoperative systolic and mean blood pressure values were compared between the two groups.ResultsPatients with POD showed lower intraoperative and postoperative minimum mean arterial pressure (MAP) values than patients without POD (60.0 mmHg vs. 65.0 mmHg, p < 0.001; and 56.0 mmHg vs. 62.0 mmHg, p < 0.001; respectively). A lower intraoperative minimum MAP value was identified as predictor for POD (odds ratio [OR] 1.246, 95% confidence interval [CI] 1.057–1.472, p = 0.009). The cut-off value for intraoperative MAP for predicting POD was ≤ 62.5 mmHg (area under the curve [AUC] 0.822, 95% CI 0.744–0.900, p < 0.001).ConclusionsMaintaining a stable intraoperative minimum MAP of > 62.5 mmHg could help to reduce the incidence of POD in microvascular head and neck reconstruction.

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.

Efficacy of dexmedetomidine in the prevention and treatment of postanesthetic shivering after cesarean section

Purpose: To assess the efficacy of dexmedetomidine in the prevention and treatment of postanesthetic shivering in cesarean section.Methods: A total of 144 pregnant women who underwent anesthesia for cesarean section between March and December 2022 were randomly divided into the study group (n = 72) and control group (n = 72). The pregnant women were given combined spinal-epidural anesthesia. Following childbirth, those in the study group were given dexmedetomidine, while those in the control group were given normalsaline. The dose of spinal anesthesia was administered based on the following criteria: intraoperative infusion, atropine usage, ephedrine usage, intraoperative bleeding, intraoperative dosage, mean arterial pressure, heart rate, blood oxygen saturation, incidence of shivering, and sedation score. Incidence of adverse reactions were recorded and compared between the two groups.Results: Intraoperative infusion volume, bleeding volume, levels of atropine and ephedrine usage, and spinal anesthesia dose were similar between the two groups (p &gt; 0.05). At 10 min post-treatment, the study group had lower mean arterial pressure, heart rate and incidence of postanesthetic shivering, as well as higher postoperative sedation score than the control group. Compared with the control group, the study group had slightly higher incidence of pregnancy-related adverse reactions, but the difference was non-significant.Conclusion: Dexmedetomidine has good efficacy in preventing and treating postanesthetic shivering in cesarean section patients. However, further clinical trials are required prior to its adoption in clinical practice.

Abstract 099: Akr1b7 CreERT2 Mice, A New Time And Renin Cell-specific Cre Inducible Model

Gene targeting in renin cells has relied on either non-inducible Cre lines that can introduce developmental effects of gene deletion or BAC transgene-based inducible lines that may be prone to spurious and/or ectopic gene expression. To circumvent these problems, we generated an inducible mouse in which CreERT2 is under the control of the Akr1b7 locus. Akr1b7 , an established marker of renin cells, is co-expressed with renin under different developmental, physiological, and pathological conditions. To study the pattern of Cre expression, we generated Akr1b7 CreERT2/+ ; R26R mTmG/+ mice in which Cre -expressing cells are labeled with GFP upon tamoxifen (Tmx) administration. At E18.5 and P5, GFP was found in Juxtaglomerular (JG) cells, along the arterioles, and in the glomerular mesangium. In adult kidneys, GFP expression was present mainly in JG cells. We did not observe any GFP + cells in vehicle-treated mice, indicating that Cre expression is tightly regulated in this model. In mice given 0.5 g/L captopril in the drinking water and a low-NaCl (0.1%) diet to induce recruitment of renin cells, GFP expression extended along the afferent arterioles and in the mesangium. To study the response to Ren1 deletion in JG cells in the mice, we generated Akr1b7 CreERT2/+ ;Ren1 cFl/- ;R26R mTmG/+ ( Ren1 c cKO) mice. Compared to control mice, Ren1 c cKO mice exhibited a marked reduction in Ren1+ cells by immunostaining and a 80.1% reduction of Ren1 mRNA levels by RT-qPCR (0.19 ± 0.04 vs 0.92 ± 0.26, p= 0.0003). Plasma renin levels were significantly decreased in Ren1 c cKO versus control mice (12,5 ± 7,0 ng/ml vs 53,7 ± 27,9 ng/ml, p= 0.003). In addition, Ren1 c cKO mice had lower mean arterial pressures (68.91 ± 5.27 mmHg vs 82.74 ± 2.63 mmHg, p= 0.0001). When subjected to a low NaCl diet + captopril, Ren1 c cKO mice were able to recruit renin GFP+ cells along arterioles, mesangial cells, and large kidney arteries, suggesting that Ren1 expression in JG cells is dispensable for recruitment. More importantly, the cells can be monitored/tracked by the expression of GFP even when they are unable to express renin.In summary, Akr1b7 CreERT2 mice constitute a suitable model for the spatial and temporal control of gene expression in renin cells and the tracking of cells even when they are not expressing renin.

Ultrasound-guided ilioinguinal/iliohypogastric nerve block compared to posterior quadratus lumborum block in patients undergoing inguinal hernia repair

ABSTRACT Background “Ilioinguinal/iliohypogastric nerve block” (IINB) has been described as effective regional anesthetic method for providing analgesia after inguinal hernia operations. Other studies have also reported that the “posterior quadratus lumborum block” (PQLB) is an effective analgesic option for lower abdominal surgeries. Herein, we compared the previous two block techniques for postoperative pain management in adults undergoing unilateral inguinal hernia repair. Methods According to the block technique, 76 adult patients scheduled for inguinal hernioplasty under general anesthesia were randomly enrolled into two groups; the PQLB and IINB groups. The block was performed after skin closure and before patient extubation. Postoperative analgesic profiles were recorded in both groups. Results The PQLB had lower heart rate and mean arterial pressure readings during postoperative assessment compared to the other group. Pain scores showed a significant decline in association with the PQLB during the first postoperative day, which resulted in a significant decline in pethidine consumption (49.17 vs. 70 mg in the IINB group) and better patient satisfaction. The duration to the first analgesic request significantly increased in association with the PQLB (13.25 vs. 8.42 hours in the IINB group). The incidence of nausea and vomiting increased significantly in the IINB group secondary to increased pethidine requirements. Conclusion PQLB is superior to IINB in providing analgesia for patients undergoing inguinal hernia repair.

Concentrated urine, low urine flow, and postoperative elevation of plasma creatinine: A retrospective analysis of pooled data.

Elevations of plasma creatinine are common after major surgery, but their pathophysiology is poorly understood. To identify possible contributing mechanisms, we pooled data from eight prospective studies performed in four different countries to study circumstances during which elevation of plasma creatinine occurs. We included 642 patients undergoing mixed major surgeries, mostly open gastrointestinal. Plasma and urinary creatinine and a composite index for renal fluid conservation (Fluid Retention Index, FRI) were measured just before surgery and on the first postoperative morning. Urine flow was measured during the surgery. The results show that patients with a postoperative increase in plasma creatinine by >25% had a high urinary creatinine concentration (11.0±5.9 vs. 8.3±5.6 mmol/L; P< 0001) and higher FRI value (3.2±1.0 vs. 2.9±1.1; P< 0.04) already before surgery was initiated. Progressive increase of plasma creatinine was associated with a gradually lower urine flow and larger blood loss during the surgery (Kruskal-Wallis test, P< 0.001). The patients with an elevation > 25% also showed higher creatinine and a higher FRI value on the first postoperative morning (P< 0.001). Elevations to > 50% of baseline were associated with slightly lower mean arterial pressure (73 ± 10 vs. 80 ± 12 mmHg; P< 0.005). We conclude that elevation of plasma creatinine in the perioperative period was associated with low urine flow and greater blood loss during surgery and with concentrated urine both before and after the surgery. Renal water conservation-related mechanisms seem to contribute to the development of increased plasma creatinine after surgery.

Effects of Remimazolam Anesthesia with Two Induction Doses on Hemodynamics and Recovery Profile in Older Patients: Comparison with Propofol Anesthesia.

Remimazolam has advantages such as hemodynamic stability and rapid onset. We investigated the effects of induction doses on hemodynamics and recovery profiles for remimazolam compared to propofol in older patients. Sixty-nine patients aged >65 years were randomly assigned to either the propofol anesthesia group (P group) or the remimazolam anesthesia group with an induction dose of 6 mg/kg/h (R6 group) or 12 mg/kg/h (R12 group), followed by 1 mg/kg/h. P group was anesthetized with 4 µg/mL of propofol effect-site concentration (Ce) with target-control infusion, followed by 2.5-3 µg/mL of Ce. The primary outcome was the difference between the baseline mean arterial pressure (MAP) and the lowest MAP during anesthesia (ΔMAP). ΔMAP was comparable between the P, R6, and R12 groups (43.8 ± 13.8 mmHg, 39.2 ± 14.3 mmHg, and 39.2 ± 13.5 mmHg, p = 0.443). However, the frequencies of vasoactive drug use were 54.5%, 17.4%, and 30.4% (p = 0.029), and the median doses of ephedrine 3 (0-6) mg, 0 (0-0) mg, and 0 (0-0) mg (p = 0.034), which were significantly different. This study showed remimazolam anesthesia with an induction dose of 6 mg/kg/h, rather than 12 mg/kg/h, could reduce the requirement for vasoactive drugs compared to propofol anesthesia.