Mean Arterial Pressure Research Articles

Cardiopulmonary function, anesthetic effects, quality of arousal, hematology, and blood biochemistry during continuous intravenous infusion of a combination solution of xylazine, butorphanol, and propofol in calves.

General anesthesia in calves is easier to perform under field conditions, total intravenous anesthesia (TIVA) than using inhalation anesthesia. In the present study, cardiopulmonary function, anesthetic effects, quality of arousal, hematology, and blood biochemistry were assessed during continuous infusion of a combination solution of 0.01% xylazine, 0.001% butorphanol, and 0.2% propofol (XBP) at doses of 6 (G6; 10μg/kg/min xylazine, 1μg/kg/min butorphanol, 200μg/kg/min propofol) and 9mL/kg/h (G9; 15μg/kg/min xylazine, 1.5μg/kg/min butorphanol 300μg/kg/min propofol). For both groups, five castrated Holstein calves received intravenous injections of xylazine (0.2mg/kg) and propofol (2mg/kg), followed by a continuous infusion of XBP for 60min to maintain anesthesia. Respiratory management consisted of tracheal intubation followed by spontaneous inhalation of pure oxygen. Cardiopulmonary, anesthesia, hematology, and blood biochemistry variables were assessed at rest (baseline) and every 5 or 15min after the start of the XBP infusion. Quality of arousal was assessed based on the swallowing reflex recovery time from the stop of XBP infusion, and the sternal position time and standing time after atipamezole administration. XBP produced adequate sedation, analgesia, and muscle relaxation in all calves and maintained stable anesthesia for 60min. As XBP infusion time passed, rectal temperature and heart rate became lower, and mean arterial blood pressure increased. In both groups, hematologic and blood biochemical effects were mild. The quality of arousal was not different, and all calves were standing. The results of the present study suggested that XBP is useful for TIVA in calves.

Effects of incremental peritoneal dialysis with low glucose-degradation product neutral pH solution on clinical outcomes.

Incremental peritoneal dialysis (IPD) could decrease unfavorable glucose exposure results and preserve (RKF). However, there is no standardization of dialysis prescriptions for patients undergoing IPD. We designed a prospective observational multi-center study with a standardized IPD prescription to evaluate the effect of IPD on RKF, metabolic alterations, blood pressure control, and adverse outcomes. All patients used low GDP product (GDP) neutral pH solutions in both the incremental continuous ambulatory peritoneal dialysis (ICAPD) group and the retrospective standard PD (sPD) group. IPD patients started treatment with three daily exchanges five days a week. Control-group patients performed four changes per day, seven days a week. A total of 94 patients (47 IPD and 47 sPD) were included in this study. The small-solute clearance and mean blood pressures were similar between both groups during follow-up. The weekly mean glucose exposure was significantly higher in sPD group than IPD during the follow-up (p < 0.001). The patients with sPD required more phosphate-binding medications compared to the IPD group (p = 0.05). The rates of peritonitis, tunnel infection, and hospitalization frequencies were similar between groups. Patients in the sPD group experienced more episodes of hypervolemia compared to the IPD group (p = 0.007). The slope in RKF in the 6th month was significantly higher in the sPD group compared to the IPD group (65% vs. 95%, p = 0.001). IPD could be a rational dialysis method and provide non-inferior dialysis adequacy compared to full-dose PD. This regimen may contribute to preserving RKF for a longer period.

Aging in females has minimal effect on changes in celiac artery blood flow during dynamic light-intensity exercise.

Blood flow to the active muscles and arterial blood pressure (ABP) increases during dynamic exercise, whereas blood flow to inactive organs (e.g., splanchnic organs and inactive limbs) declines. Aging leads to exaggerated ABP responses to exercise in females, but whether this is related to greater splanchnic vasoconstriction is unknown. This study sought to clarify the effect of aging in females on celiac artery blood flow during dynamic light-intensity exercise. Twelve healthy young females (YF: 20±2yrs, mean±SD) and 12 healthy older females (OF: 71±4yrs) performed dynamic knee-extension and -flexion exercise at 30% of heart rate reserve for 4-min. The absolute changes from baseline (Δ) for mean arterial blood pressure (MAP), celiac artery mean blood flow (celMBF), and celiac vascular conductance (celVC) during exercise were calculated. ABP was measured using an automated sphygmomanometer, and celMBF was recorded by Doppler ultrasonography. The increase in MAP during exercise was greater in OF than in YF (YF: +14±7mmHg, OF: +24±13mmHg, P=0.028). The celMBF decreased during exercise in both groups, but there was no significant difference in the response between YF and OF (YF: -93.0±66.1mL/min, OF: -89.6±64.0mL/min, P=0.951). The celVC also decreased during exercise and remained lower than baseline during exercise. However, the response was not different between YF and OF (YF: -1.8±1.0mL/min/mmHg, OF: -1.5±0.6mL/min/mmHg, P=0.517). These results demonstrate that aging in females has minimal influence on splanchnic artery hemodynamic responses during dynamic light-intensity exercise, suggesting that exaggerated ABP responses during exercise in OF are not due to greater splanchnic vasoconstriction.

Fine-tuning the needle: analysis of acupuncturist response to alarming events during gynecological oncology surgery.

Examining an intra-operative acupuncture/acupressure setting, with real-time "fine-tuning" in response to alarming events (AEvs) during gynecological oncology surgery. Narratives of acupuncturists providing intraoperative acupuncture during gynecological oncology surgery were qualitatively analyzed. These described real time "fine-tuning" in response to AEvs during surgery, identified through hemodynamic changes (e.g., systolic/diastolic arterial pressure); bispectral index (BIS) elevation; and feedback from surgeons and anesthesiologists. Documentation of acupuncturist responses to AEvs was addressed as well. Of the 48 patients in the cohort, 33 had at least one intraoperative AEv (69%), of which 30 were undergoing laparoscopic surgery and 18 laparotomies. A total of 77 AEvs were documented throughout surgery (range 1-7; mean: 2.3 events per patient), identified through increased (63 events) or decreased (8) mean arterial pressure (MAP); increased BIS levels (2), or other hemodynamic parameters (4). Integrative oncology interventions implemented in response to AEs included acupressure alone (59); combining acupressure with acupuncture (10); or acupuncture alone (4). In 54 (70%) events, documentation was provided from beginning to conclusion of the AEv, with a mean duration of 9.7 min, with 32 events including a documented anesthesiologist intervention. The present study demonstrated the feasibility of intraoperative acupuncture with acupressure, with ongoing "fine-tuning" to AEvs identified through objective pain-related parameters (MAP, heart rate and BIS) and real-time input from surgeons and anesthesiologists. Documentation of the intraoperative IO practitioner's response to these AEvs is important, and should be addressed in future research of the innovative integrative model of care. CMC-18-0037 (Carmel Medical Center, June 11, 2018).

Assessing donor-recipient arterial pressure dynamics in STA-MCA bypass for moyamoya disease

BackgroundIn bypass surgery for moyamoya disease (MMD), the superficial temporal artery’s (STA) pressure needs to surpass that of the cortical M4 recipient of the middle cerebral artery (MCA), boosting cerebral blood flow into the MCA and enhancing cerebral circulation. This study investigates the STA-MCA arterial pressure parameters and gradients during bypass surgery, aiming to deepen our understanding of hemodynamic shifts pre- and post-operation.MethodsDSA imaging data were prospectively collected from patients diagnosed with bilateral MMD who underwent STA-MCA bypass surgery between 2022 and 2023 and stratified according to the Suzuki stage. The mean arterial pressure (MAP) of the donor and recipient arteries was directly measured during the STA-MCA bypass procedure, and these data were statistically analyzed and evaluated.ResultsAmong 48 MMD patients, Suzuki grading revealed that 43.8% were in early stages (II and III), while 56.2% were in advanced stages (IV, V, and VI). Predominantly, 77.1% presented with ischemic-type MMD and 22.9% with hemorrhagic type. Pre-bypass assessments showed that 62.5% exhibited antegrade blood flow direction, and 37.5% had retrograde. The mean recipient artery pressure was 35.0 ± 2.3 mmHg, with a mean donor-recipient pressure gradient (δP) of 46.4 ± 2.5 mmHg between donor and recipient arteries. Post-bypass, mean recipient artery pressure increased to 73.3 ± 1.6 mmHg. No significant correlation (r = 0.18, P = 0.21) was noted between δP and Suzuki staging.ConclusionOur study elucidated that cerebral blood pressure significantly decreases beyond the moyamoya network at the distal M4 segment. Furthermore, we observed bidirectional flow in MCA territories and a significant positive pressure gradient between the STA and M4 segments. The lack of correlation between Suzuki stages and M4 pressures indicates that angiographic severity may not reflect hemodynamic conditions before surgery, highlighting the need for customized surgical approaches.

Physiologic Determinants of Near-Infrared Spectroscopy-Derived Cerebral and Tissue Oxygen Saturation Measurements in Critically Ill Patients.

Near-infrared spectroscopy (NIRS) is a potentially valuable modality to monitor the adequacy of oxygen delivery to the brain and other tissues in critically ill patients, but little is known about the physiologic determinants of NIRS-derived tissue oxygen saturations. The purpose of this study was to assess the contribution of routinely measured physiologic parameters to tissue oxygen saturation measured by NIRS. An observational sub-study of patients enrolled in the Role of Active Deresuscitation After Resuscitation-2 (RADAR-2) randomized feasibility trial. Two ICUs in the United Kingdom. Patients were recruited for the RADAR-2 study, which compared a conservative approach to fluid therapy and deresuscitation with usual care. Those included in this sub-study underwent continuous NIRS monitoring of cerebral oxygen saturations (SctO2) and quadriceps muscle tissue saturations (SmtO2). Synchronized and continuous mean arterial pressure (MAP), heart rate (HR), and pulse oximetry (oxygen saturation, Spo2) measurements were recorded alongside NIRS data. Arterial Paco2, Pao2, and hemoglobin concentration were recorded 12 hourly. Linear mixed effect models were used to investigate the association between these physiologic variables and cerebral and muscle tissue oxygen saturations. Sixty-six patients were included in the analysis. Linear mixed models demonstrated that Paco2, Spo2, MAP, and HR were weakly associated with SctO2 but only explained 7.1% of the total variation. Spo2 and MAP were associated with SmtO2, but together only explained 0.8% of its total variation. The remaining variability was predominantly accounted for by between-subject differences. Our findings demonstrated that only a small proportion of variability in NIRS-derived cerebral and tissue oximetry measurements could be explained by routinely measured physiologic variables. We conclude that for NIRS to be a useful monitoring modality in critical care, considerable further research is required to understand physiologic determinants and prognostic significance.

Comparison the Cerebroprotective Effect of Sevoflurane and Propofol in Patients with Carotid Artery Stenosis Undergoing Coronary Artery Bypass Grafting: A Randomized Clinical Study

Objective: The Objective of the study was to evaluate the perioperative cerebral protective effect of sevoflurane and propofol in patients with carotid artery stenosis undergoing coronary artery bypass grafting. Materials and Methods: A randomized clinical study included 200 patients with preoperative carotid artery stenosis &amp;lt;50% scheduled for cardiac surgery with cardiopulmonary bypass. The patients were classified into 2 groups (each=100), Sevoflurane group: The patients received sevoflurane (concentration 1% to 4%) as an inhalational agent. Propofol group: The patients received propofol infusion (4-6 mg/kg/hr). The sevoflurane and propofol were given during the whole procedure (before, during, and after cardiopulmonary bypass). The monitors included heart rate, mean arterial blood pressure (MAP), central venous pressure and cerebral near-infrared spectroscopy (NIRS), the incidence of postoperative cognitive dysfunction and stroke. Results: There was no significant difference in the perioperative heart rate, mean arterial blood pressure, central venous pressure, and the right or left regional cerebral oxygen saturation between the two groups (P&amp;gt;0.05). The incidence of postoperative neurological complication was significantly lower with sevoflurane than propofol (P=0.012). The incidence of delirium was significantly lower with sevoflurane than propofol (P=0.023). The incidence of stroke was lower with sevoflurane than propofol, but the difference was insignificant (P=0.682). The ICU and hospital length of stay were shorter with sevoflurane than propofol (P=0.013, P=0.033 respectively). Conclusions: The sevoflurane was associated with a lower incidence of postoperative cognitive dysfunction than propofol in patients with carotid artery stenosis undergoing coronary artery bypass grafting.

Continuous Infusion of Ketamine in Mechanically Ventilated Patients with SARS-CoV-2

Background. Widespread drug shortages led to higher utilization of ketamine in our intensive care unit, especially among patients with SARS-CoV-2. Objectives. To evaluate the impact of continuous infusion of ketamine on vasopressor requirements in patients with SARS-CoV-2. Method. This was a single-center, retrospective, cohort study comparing mechanically ventilated (MV), adult patients with SARS-CoV-2 receiving either propofol or ketamine for at least 72 hours. Results. 84 patients (mean age of 61-year-old, 68% male) were analyzed. 31 patients received ketamine, and 53 patients received propofol. Mean vasopressor doses were not significantly different between ketamine and propofol groups at prespecified timepoints. However, mean arterial pressures (MAP) were higher in the ketamine group at 24 h, 48 h, and 96 h postsedative initiation. The median opioid infusion requirements were 3 vs. 12.5 mg/hr (p&lt;0.0001) for ketamine and propofol groups, respectively. Comparing to propofol, C-reactive protein (CRP) values were significantly lower in the ketamine group at 24 h (7.53 vs. 15.9 mg/dL, p=0.03), 48 h (5.23 vs. 14.1 mg/dL, p=0.0083), and 72 h (6.4 vs. 12.1 mg/dL, p=0.0085). Conclusion. In patients with SARS-CoV-2 on MV, there was no difference in the vasopressor requirement in patients receiving ketamine compared to propofol. Nevertheless, the use of ketamine was associated with higher MAP, reductions in CRP in select timepoints, and overall lower opioid requirements.

The acute effect of inhaled nitric oxide on the exercise capacity of patients with advanced interstitial lung disease: a randomized controlled trial

BackgroundInhaled nitric oxide (iNO) selectively acts on the pulmonary vasculature of ventilated lung tissue by reducing pulmonary vascular resistance and intrapulmonary shunt. This effect may reduce ventilation/perfusion mismatch and decrease pulmonary hypertension in patients with interstitial lung disease.MethodsIn a prospective, single-blinded, randomized, placebo-controlled trial, participants with advanced interstitial lung disease, underwent two separate six-minute walk tests (6MWT): one with iNO and the other with a placebo. The primary outcome measured the difference in meters between the distances covered in the two tests. Secondary outcomes included oxygen saturation levels, distance-saturation product, and Borg dyspnea score. A predefined subgroup analysis was conducted for patients with pulmonary hypertension.ResultsOverall, 44 patients were included in the final analysis. The 6MWT distance was similar for iNO treatment and placebo, median 362 m (IQR 265-409) vs 371 m (IQR 250-407), respectively (p = 0.29). Subgroup analysis for patients with pulmonary hypertension showed no difference in 6MWT distance with iNO and placebo, median 339 (256-402) vs 332 (238-403) for the iNO and placebo tests respectively (P=0.50). No correlation was observed between mean pulmonary artery pressure values and the change in 6MWT distance with iNO versus placebo (spearman correlation Coefficient 0.24, P=0.33).ConclusionIn patients with advanced interstitial lung disease, both with and without concurrent pulmonary hypertension, the administration of inhaled nitric oxide failed to elicit beneficial effects on the six-minute walk distance and oxygen saturation. The use of inhaled NO was found to be safe and did not lead to any serious side effects.Trial registration(NCT03873298, MOH_2018-04-24_002331).

Rate of Post Obstructive Diuresis in Rapid Versus Gradual Bladder Decompression in Patients with Chronic Urinary Retention

Background: Post-obstructive diuresis (POD) is a polyuric state in which copious amounts of salt and water are eliminated after the relief of a urinary tract obstruction. POD is a clinical diagnosis based on urine output exceeding 200 mL per hour for two or more consecutives hours or 3L in 24 hours after decompressing an obstructed bladder, bilateral ureteric obstruction or unilateral ureteric obstruction in a solitary kidney. Methodology: This was a prospective, randomized study in which patients with chronic urinary retention were randomized into two groups: A and B. Group A had rapid urinary decompression with 18Fr urethral catheter attached to a urine bag, while group B had gradual decompression using a urethral catheter attached to an intravenous fluid giving set which was then attached to urine bag. Post obstructive diuresis in each group were assessed at designated times. Data Analysis and Result Presentation: Data was analyzed using the Statistical Package for Social Sciences (IBM) SPSS version 21. Data was summarized by descriptive statistics. The two arms were compared for similarities in demographic variables. Continuous and categorical variables were compared using student t- test and Pearsons‘ Chi – square respectively. Significant p value was 0.05. Result: Sixty patients were recruited into the study and randomized into group A (rapid urinary decompression) and B (gradual urinary decompression) with 30 patients in each group. Thirteen patients (43.33%) had post obstructive diuresis in group A compared to 15 patients (50%) in group B. p value of 0.584. Diuresis resolved within 24 hours in 9 patients (30%) in group A and 11 patients (36.7%) in group B. p value of 0.999. The mean reduction in systolic blood pressure was 8.21 ± 2.63mmHg in group A and 7.63 ± 2.14mmHg in group B. p value of 0.583. The mean reduction diastolic blood pressure was 3.84 ± 1.31mmHg in group A and 3.41 ± 1.16mmHg in group B. P value of 0.624. No patient in both groups developed hypotension (BP of &amp;lt;90/60). Conclusion: There was no statistically significant different in post obstructive diuresis. However, over 46.7% of patients had diuresis in both groups without any one developing hypotension. This may be due to routine prophylactic fluid and electrolyte replacement using normal saline.

Intravenous angiotensin II as an add-on to standard of care vasopressors in patients with refractory shock on mechanical circulatory support: a single centre retrospective case series

Abstract Funding Acknowledgements None. Background Refractory shock is life-threatening condition characterized by hypotension with mean arterial pressure (MAP) less than 65 mmHg and end-organ dysfunction, despite volume resuscitation and high doses of vasopressors. Mortality rates in refractory shock exceeds 90%. Angiotensin II (Ang II) is a non-catecholamine vasopressor that targets the renin-angiotensin-aldosterone system by agonism of the angiotensin type 1 receptors. Ang II has been studied in settings of vasodilatory shock, however there is paucity of data regarding the usage of Ang II in patients with preexisting heart failure or in patients requiring mechanical circulatory support (MCS), either short term such as venoarterial extracorporeal membrane oxygenation (VA-ECMO) or long term such as left ventricular assist device (LVAD) (1,2). Purpose This report is aimed to analyse baseline characteristics of patients who have received Ang II from the moment it became available in our institution (January 2023). Methods Five patients were included in this retrospective analyses. Demographic, clinical and laboratory parameters as well as hourly changes of vasopressors doses, MAP, lactates, and diuresis were collected and analysed. Results Median age of 5 included patients, 4 of whom were male, was 53 years old (range 18-57). The most common comorbidities were chronic kidney disease (n=3), diabetes mellitus (n=3) and arterial hypertension (n=3), treated with valsartan as chronic therapy. All patients presented with severe shock. 4 patients were on VA-ECMO support, 1 had additionally implanted Impella for left ventricular unloading and 2 had implanted LVAD. All patients had severely reduced left ventricular ejection fraction (median 15%, range 10-25%). In 4 cases vasopressors were initiated due to sepsis and in 1 case during cardiopulmonary resuscitation. Median values prior to administration of Ang II were as following: MAP 51 mmHg (range 41-56 mmHg), lactates 6.7 mmol/L (range 2.4-10.7 mmol/L) and Sequential Organ Failure Assessment (SOFA) score 9 (range 5-11). Four hours following administration of Ang II median MAP was 61 mmHg (range 54-77 mmHg). Patient who ultimately survived had better response to Ang II, with median rise of MAP of 22 mmHg (range 12-22 mmHg). In contrast, patients who ultimately died didn’t respond to Ang II, with rise of MAP of only 2.5 mmHg. Median duration of Ang II administration was 52 h (range 20-96 h). 60% of patients are alive up to the present day. Complete patient data are shown in Table 1. Hourly changes of vasopressor doses and MAP are shown in Figure 1. Conclusion Ang II is an effective vasopressor with rapid effect. This case series suggests that it may be considered as salvage treatment option in patients on MCS with refractory shock. Patients who responded to Ang II had better survival, similar to previous findings. Therefore, Ang II should be considered in earlier phases of shock when maximum doses of vasopressors have not yet been reached.

Perfusion index and mean arterial pressure after return of spontaneous circulation in out-of hospital cardiac arrest (OHCA) and their relationship with perfusion and survival

Abstract Funding Acknowledgements None. Background Current guidelines for post-cardiac arrest care recommend targeting mean arterial pressure (MAP) to restore adequate perfusion indicated by adequate urine output (UO) and normal or decreasing lactate, avoiding hypotension (MAP &amp;lt; 65 mmHg). The peripheral perfusion index (PI) is the ratio of the pulsatile blood flow to the non-pulsatile blood flow measured peripherally by a standard pulse-oximeter, and it represents a promising non-invasive tool to assess perfusion. The goal of this study is to assess whether prehospital PI and MAP measurements are associated with lactate clearance (LC), adequate UO and 30-days survival with good neurological outcome. Methods A retrospective analysis of prospectively collected data (January 2018 - March 2023) in two cardiac arrest registries located in Italy and Belgium was performed. PI was automatically and continuously measured by the manual monitor/defibrillator. The mean PI value of each minute after ROSC was extracted from the monitor data report and the mean value of 30 min of PI monitoring (MPI30) was calculated and categorized in tertiles (MPI30 T1-T3). The lowest prehospital value for MAP recording was considered. LC was defined by a serum lactate level &amp;lt;2 mmol/L at 6 hours. Inadequate UO was defined as &amp;lt; 0.5mL/kg/h averaged at 12 hours. Neurological outcome was assessed with the Cerebral Performance Category (CPC) at 30 days. Results Out of the 397 OHCA patients admitted to the ICU after ROSC enrolled over the study period 206 had a MPI30 value available and were included in this study; MAP value was available in 186 patients. In the subgroup of patients with hypotension, patients with MPI30 in T1 showed higher incidence of inadequate UO at 12 hours (78.9% vs 25.8%, p&amp;lt;0.001). At multivariable logistic regression, after adjusting for MAP, shockable rhythm, age, and dosage of adrenaline administered, MPI30 was independently associated with inadequate UO (OR 0.68, 95% CI 0.50-0.91, p=0.01). Patients with hypotension and MPI30 in T1 showed lower LC at 6h (15.8% vs 43.4%, p=0.02) when compared to the remaining population. At multivariable Cox proportional-hazard regression, after correction for shockable rhythm, age, and total amount of adrenaline administered, patients with hypotension and MPI30 in T1 showed lower survival with CPC 1-2 at 30 days (HR 2.61, 95% CI 1.52-4.51, p=&amp;lt;0.001) when compared to patients without hypotension or with hypotension but MPI30 in T2-T3. No difference in LC, adequate UO and survival with good neurological outcome was found between patients with hypotension and MPI30 in T2-T3 compared to patients without hypotension. Conclusion PI is a useful indicator of perfusion in patients with hypotension after OHCA. Patients with hypotension and reduced PI showed higher incidence of inadequate UO and lower incidence of LC, as well as association with lower survival at 30 days with CPC 1-2.Lactate clearenceSurvival at 30days with CPC 1-2

Population kinetic/pharmacodynamic modelling of the haemodynamic effects of cafedrine/theodrenaline (Akrinor) under general anaesthesia.

The 20:1 combination of cafedrine and theodrenaline (C/T) is widely used in Germany for the treatment of arterial hypotension. Since there is little knowledge about the impact of covariates on the effect, the aim was to develop a kinetic/pharmacodynamic covariate model describing mean arterial pressure (MAP), systolic (SBP) and diastolic blood pressure (DBP), and heart rate (HR) for 30 min after the administration of C/T. Data of patients receiving C/T from the HYPOTENS study (NCT02893241, DRKS00010740) were analysed using nonlinear mixed-effects modelling techniques. Overall, 16 579 measurements from 315 patients were analysed. The combination of two kinetic compartments and a delayed effect model, coupled with distinct Emax models for HR, SBP and DBP, described the data best. The model included age, sex, body mass index (BMI), antihypertensive medication, American Society of Anaesthesiologists (ASA) physical status classification grade, baseline SBP at the time of hypotension and pre-surgery HR as covariates (all P < .001). A higher baseline SBP led to a lower absolute increase in MAP. Patients with higher age, higher BMI and lower ASA grade showed smaller increases in MAP. The initial increase was similar for male and female patients. The long-term effect was higher in women. Concomitant antihypertensive medication caused a delayed effect and a lower maximum MAP. The HR increased only slightly (median increase 2.6bpm, P < .001). Seven covariates with an impact on the effect of C/T could be identified. The results will enable physicians to optimize the dose with respect to individual patients.

Oxygen delivery and consumption in comatose out-of-hospital cardiac arrest patients are affected by blood pressure targets

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Grosserer L. F. Foghts Fond Background Hemodynamic instability is common after resuscitated out-of-hospital cardiac arrest (OHCA). Preventing inadequate oxygen delivery (DO2) to the cells and thus not meeting oxygen demand is crucial to prevent further organ dysfunction. Additionally, oxygen uptake in the cells may be impaired. Oxygen consumption (VO2; the amount of oxygen consumed by the body per minute) could thus also be affected in OHCA. Purpose This study aimed to describe the effect of different mean arterial blood pressure (MAP) and partial arterial oxygen pressure (PaO2) targets on DO2 and VO2. Methods This post-hoc study is based on the BOX trial, a 2x2 factorial design that randomized OHCA patients to a MAP of either 63 mmHg (MAP63) or 77 mmHg (MAP77) and a partial pressure of arterial oxygen of 9 to 10 kPa or a liberal oxygen target of a PaO2 of 13 to 14 kPa at two cardiac centers in Denmark. Pulmonary artery catheters were placed to evaluate cardiac output and collect mixed venous blood samples at prespecified time points. Oxygen blood contents were calculated for arterial (CaO2) and mixed venous blood (CvO2) as Hgb (mg/dl) x 10 x 1.39 x Saturation O2 (proportion) + 0.0225 x PaO2. DO2 = CO x CaO2, and VO2 = CO x (CaO2-CvO2). Results This study included 715 patients (90% of the total cohort with a pulmonary catheter) for analysis. A restrictive or liberal oxygen supplement did not affect DO2 or VO2 during the initial 48 hours. The MAP77 group exhibited on average 11% higher DO2 (95%CI: 6%-15%) and on average a 6% higher VO2 in the first 48 hours (95%CI: 3%-10%) compared to the MAP63 group (see Figure 1). Conclusion Targeting a PaO2 of either 9 to 10 kPa or 13 to 15 kPa resulted in no significant changes in the provision of oxygen to the cells, nor did it increase the consumption of oxygen. In contrast, targeting a MAP of 77 mmHg resulted in an increase in both the provision of oxygen and consumption of oxygen compared to a MAP target of 63 mmHg.Figure 1

Influence of Blood Pressure Reduction on Pulse Wave Velocity in Primary Hypertension: A Meta-Analysis and Comparison With an Acute Modulation of Transmural Pressure.

Increased arterial stiffness and pulse wave velocity (PWV) of the aorta and large arteries impose adverse hemodynamic effects on the heart and other organs. Antihypertensive treatment reduces PWV, but it is unknown whether this results from an unloading of stiffer elements in the arterial wall or is due to an alternate functional or structural change that might differ according to class of antihypertensive drug. We performed a systematic review and meta-analysis of the effects of different antihypertensive drug classes and duration of treatment on PWV with and without adjustment for change in mean arterial blood pressure (BP; study 1) and compared this to the change in PWV after an acute change in transmural pressure, simulating an acute change in BP (study 2). A total of 83 studies involving 6200 subjects were identified. For all drug classes combined, the reduction of PWV was 0.65 (95% CI, 0.46-0.83) m/s per 10 mm Hg reduction in mean arterial BP, a change similar to that induced by an acute change in transmural pressure in a group of hypertensive subjects. When adjusted for change in mean arterial BP, the reduction in PWV after treatment with beta-blockers or diuretics was less than that after treatment with angiotensin-converting enzyme inhibitors/angiotensin receptor antagonists or calcium channel antagonists. Reduction in PWV after antihypertensive treatment is largely explained by the reduction in BP, but there are some BP-independent effects. These might increase over time and contribute to better outcomes over the long term, but this remains to be demonstrated in long-term clinical trials.

Risk factors and early prediction of cardiorenal syndrome type 3 among acute kidney injury patients: a cohort study

Background Type 3 cardiorenal syndrome (CRS type 3) triggers acute cardiac injury from acute kidney injury (AKI), raising mortality in AKI patients. We aimed to identify risk factors for CRS type 3 and develop a predictive nomogram. Methods In this retrospective study, 805 AKI patients admitted at the Department of Nephrology, Second Hospital of Shanxi Medical University from 1 January 2017, to 31 December 2021, were categorized into a study cohort (406 patients from 2017.1.1-2021.6.30, with 63 CRS type 3 cases) and a validation cohort (126 patients from 1 July 2021 to 31 Dec 2021, with 22 CRS type 3 cases). Risk factors for CRS type 3, identified by logistic regression, informed the construction of a predictive nomogram. Its performance and accuracy were evaluated by the area under the curve (AUC), calibration curve and decision curve analysis, with further validation through a validation cohort. Results The nomogram included 6 risk factors: age (OR = 1.03; 95%CI = 1.009–1.052; p = 0.006), cardiovascular disease (CVD) history (OR = 2.802; 95%CI = 1.193–6.582; p = 0.018), mean artery pressure (MAP) (OR = 1.033; 95%CI = 1.012–1.054; p = 0.002), hemoglobin (OR = 0.973; 95%CI = 0.96-–0.987; p < 0.001), homocysteine (OR = 1.05; 95%CI = 1.03–1.069; p < 0.001), AKI stage [(stage 1: reference), (stage 2: OR = 5.427; 95%CI = 1.781–16.534; p = 0.003), (stage 3: OR = 5.554; 95%CI = 2.234–13.805; p < 0.001)]. The nomogram exhibited excellent predictive performance with an AUC of 0.907 in the study cohort and 0.892 in the validation cohort. Calibration and decision curve analyses upheld its accuracy and clinical utility. Conclusions We developed a nomogram predicting CRS type 3 in AKI patients, incorporating 6 risk factors: age, CVD history, MAP, hemoglobin, homocysteine, and AKI stage, enhancing early risk identification and patient management.

Enhancing patient comfort in varicose vein treatment through combined lidocaine and ropivacaine tumescent anesthesia

ObjectiveTo compare the analgesic effects of specific tumescent anesthetic solutions composed of lidocaine, ropivacaine, or a combination of lidocaine and ropivacaine during endovenous radiofrequency ablation for the treatment of great saphenous vein varicosities.MethodThis study included 149 patients with lower limb varicose veins who were admitted to our department between 2019 and 2023. The patients were randomly assigned to three groups: the lidocaine group (Group I), the ropivacaine group (Group II), and the lidocaine + ropivacaine group (Group III). Intraoperative vital signs, intraoperative and postoperative visual analog scale (VAS) pain scores, and long-term treatment outcomes were assessed using the venous clinical severity score (VCSS) based on clinical performance.ResultsThere were no significant differences in age, body mass index, operative time, or blood loss among the three groups (P ≥ 0.05). The differences in the mean arterial pressure and heart rate during surgery in Group II were significantly greater than those in Groups I and III (P &amp;lt; 0.05). The intraoperative VAS scores in Group II were higher than those in Groups I and III (P &amp;lt; 0.05) and at 8 and 12 h postoperatively. There were no significant differences in VCSS among the groups (P ≥ 0.05).ConclusionThe use of a tumescent anesthetic solution composed of lidocaine and ropivacaine significantly improved patient comfort during the perioperative period without affecting surgical outcomes. This formulation can be considered safe and reliable for preparing tumescent anesthesia solutions.

Development and Validation of a Prediction Model for Acute Hypotensive Events in Intensive Care Unit Patients

Background: Persistent hypotension in the intensive care unit (ICU) is associated with increased mortality. Predicting acute hypotensive events can lead to timely intervention. We aimed to develop a prediction model of acute hypotensive events in patients admitted to the ICU. Methods: We included adult patients admitted to the Nagoya City University (NCU) Hospital ICU between January 2018 and December 2021 for model training and internal validation. The MIMIC-III database was used for external validation. A hypotensive event was defined as a mean arterial pressure &lt; 60 mmHg for at least 5 min in 10 min. The input features were age, sex, and time-series data for vital signs. We compared the area under the receiver-operating characteristic curve (AUROC) of three machine-learning algorithms: logistic regression, the light gradient boosting machine (LightGBM), and long short-term memory (LSTM). Results: Acute hypotensive events were found in 1325/1777 (74.6%) and 2691/5266 (51.1%) of admissions in the NCU and MIMIC-III cohorts, respectively. In the internal validation, the LightGBM model had the highest AUROC (0.835), followed by the LSTM (AUROC 0.834) and logistic regression (AUROC 0.821) models. Applying only blood pressure-related features, the LSTM model achieved the highest AUROC (0.843) and consistently showed similar results in external and internal validation. Conclusions: The LSTM model using only blood pressure-related features had the highest AUROC with comparable performance in external validation.

Ionized hypocalcemia as a prognostic factor of early mortality in traumatic brain injury

ABSTRACT Traumatic brain injury (TBI) is a common neurological condition. It can affect mental, physical, and cognitive functions and is a common cause of mortality. Electrolytes imbalance is common in those patients. Effective therapy of electrolytes abnormalities improves neurological outcome and reduces mortality. Therefore, we studied the predictive significance of ionized hypocalcemia for early mortality in TBI patients. Patients and method This observational study in the intensive care units of the Ain Shams University hospitals was done on sixty adult patients with TBI of both sexes, divided into two groups: group A (ionized hypocalcemic patients), and group B (normocalcemic patients). On admission, medical history, physical examination including neurological evaluation, and appropriate investigations were performed. Ionized calcium was measured at the start of the 28-day study and then every five days after that. Results There was no statistically significant difference between the two groups for demographic data, brain injury type, or the number of intubated patients (p > 0.05). There was a statistically significant difference for diffuse axonal damage, subdural hemorrhage, cerebral edema, GCS, and mean blood pressure (p < 0.001). Serum ionized calcium in group A was significantly lower than in group B on the day of admission and day five (p < 0.001). On the day of admission, there was a significant difference in serum sodium (p < 0.05). In both groups, there was a significant difference in the ICU stay as regards survivors (p < 0.001). There was a statistically significant difference in 28-day mortality between the two groups (p = 0.001). Conclusion In TBI patients, ionized hypocalcemia on admission and on day five, hypernatremia and disturbed conscious level are strongly linked to greater fatality rates.

Reperfusion therapies in patients with intermediate- and high-risk pulmonary embolism: insights from a multicenter registry

Abstract Funding Acknowledgements None. Background Most acute pulmonary embolism (PE) patients receive anticoagulation as a sole treatment. Reperfusion therapies are required in high-risk (HR) and in intermediate-risk (IR)-PE patients with clinical deterioration. Systemic thrombolysis (ST) is the first-line reperfusion therapy, but due to contraindications and major bleeding concerns, catheter-directed therapies (CDT) are rising as a suitable alternative. Purpose The main objective of this study was to look for predictors that lead physicians to decide between different PE therapies in a contemporary cohort of patients. Methods This ambispective registry included consecutive IR- and HR-acute PE patients evaluated by local Pulmonary Embolism Response Team in two tertiary centers from 2014 to 2022. The patients were grouped according to the elected therapy: anticoagulation alone, CDT or ST. If more than one reperfusion therapy was used, the patient was assigned to the group of the first administered therapy. Predictors of reperfusion therapy assignment were evaluated using a logistic regression analysis. Also, early safety outcomes and procedural results after CDT were analyzed. Results A total of 274 patients were included. Of them, 112 received only anticoagulation, 96 received ST as primary treatment, and 66 underwent CDT at first. Baseline characteristics are displayed in Picture 1. Patients in the ST group were significantly younger (p&amp;lt;0.01). Comorbidities were higher in the CDT group compared to the other two. Patients undergoing CDT or ST had higher PE severity parameters at hospital admission than the anticoagulation group (e.g. shock index, RV involvement, or lactate levels; p&amp;lt;0.01 for all). The Pulmonary Embolism Severity Index score, which incorporates comorbidities and PE severity parameters, was higher in CDT patients compared to the other two groups (p&amp;lt;0.01). Picture 2 shows the trend in the choice between the two primary reperfusion therapies over the years. After multivariable analysis, the Charlson comorbidity index, recent surgery and bilateral central PE remained independent predictors for the use of CDT instead of ST (p&amp;lt;0.05 for all). A significant decrease in the systolic and mean pulmonary artery pressure and a significant increase in systolic blood pressure after procedure was detected in patients undergoing CDT. Regarding early safety outcomes, intracranial bleeding occurred only in the ST group. In contrast, the incidence of major bleeding, acute kidney injury and 30-day mortality did not differ between CDT and ST groups. Conclusion This contemporary registry used CDT as primary therapy in 24% of IHR and HR patients, mainly in comorbid and post-surgical patients, and increased over time. CDT was a safe and effective alternative to ST, achieving significant and early improvement in right ventricular function and hemodynamics.Baseline characteristicsChoice of reperfusion therapy over time