Optimal target mean arterial pressure for patients with sepsis-associated encephalopathy: a retrospective cohort study.

BACKGROUND: Sepsis-associated encephalopathy (SAE) patients often experience changes in intracranial pressure and impaired cerebral autoregulation. Mean arterial pressure (MAP) plays a crucial role in cerebral perfusion pressure, but its relationship with mortality in SAE patients remains unclear. This study aims to investigate the relationship between MAP and the risk of 28-day and in-hospital mortality in SAE patients, providing clinicians with the optimal MAP target. METHODS: We retrospectively collected clinical data of patients diagnosed with SAE on the first day of ICU admission from the MIMIC-IV (v2.2) database. Patients were divided into four groups based on MAP quartiles. Kruskal-Wallis H test and Chi-square test were used to compare clinical characteristics among the groups. Restricted cubic spline and segmented Cox regression models, both unadjusted and adjusted for multiple variables, were employed to elucidate the relationship between MAP and the risk of 28-day and in-hospital mortality in SAE patients and to identify the optimal MAP. Subgroup analyses were conducted to assess the stability of the results. RESULTS: A total of 3,816 SAE patients were included. The Q1 group had higher rates of acute kidney injury and vasoactive drug use on the first day of ICU admission compared to other groups (P < 0.01). The Q1 and Q4 groups had longer ICU and hospital stays (P < 0.01). The 28-day and in-hospital mortality rates were highest in the Q1 group and lowest in the Q3 group. Multivariable adjustment restricted cubic spline curves indicated a nonlinear relationship between MAP and mortality risk (P for nonlinearity < 0.05). The MAP ranges associated with HRs below 1 for 28-day and in-hospital mortality were 74.6-90.2 mmHg and 74.6-89.3 mmHg, respectively.The inflection point for mortality risk, determined by the minimum hazard ratio (HR), was identified at a MAP of 81.5 mmHg. The multivariable adjusted segmented Cox regression models showed that for MAP < 81.5 mmHg, an increase in MAP was associated with a decreased risk of 28-day and in-hospital mortality (P < 0.05). In Model 4, each 5 mmHg increase in MAP was associated with a 15% decrease in 28-day mortality risk (HR: 0.85, 95% CI: 0.79-0.91, p < 0.05) and a 14% decrease in in-hospital mortality risk (HR: 0.86, 95% CI: 0.80-0.93, p < 0.05). However, for MAP ≥ 81.5 mmHg, there was no significant association between MAP and mortality risk (P > 0.05). Subgroup analyses based on age, congestive heart failure, use of vasoactive drugs, and acute kidney injury showed consistent results across different subgroups.Subsequent analysis of SAE patients with septic shock also showed results similar to those of the original cohort.However, for comatose SAE patients (GCS ≤ 8), there was a negative correlation between MAP and the risk of 28-day and in-hospital mortality when MAP was < 81.5 mmHg, but a positive correlation when MAP was ≥ 81.5 mmHg in adjusted models 2 and 4. CONCLUSION: There is a nonlinear relationship between MAP and the risk of 28-day and in-hospital mortality in SAE patients. The optimal MAP target for SAE patients in clinical practice appears to be 81.5 mmHg.

Comparative analysis of central aortic blood pressure, pulse wave velocity & arterial stiffness in patients with obstructive airway disease.

BACKGROUND: As the pulmonary system and cardiovascular system are intimately linked, patients with chronic obstructive pulmonary disease (COPD) and asthma have high risk for developing cardiovascular diseases (CVDs) and altered central hemodynamic. OBJECTIVE: We aim to assess the central aortic blood pressure (CABP) indices, pulse wave velocity (PWV) and other indicators of arterial stiffness in Indian patients with COPD and bronchial asthma. METHODS: This is a single-center, cross-sectional study conducted in outpatients diagnosed with either chronic stable phase of COPD or bronchial asthma. CABP indices, vascular age, arterial stiffness and central hemodynamics were measured in patients. RESULTS: Of 193 patients with obstructive airway disease who were enrolled, (n = 81 had COPD and n = 112 had partially-controlled bronchial asthma) the proportion of male patients was higher in both groups. The PWV, augmentation index (AI) and vascular age (VA) were significantly higher in patients with COPD compared to those with bronchial asthma (all, p < 0.05). CONCLUSION: The study showed that PWV, AI and VA were higher in patients with stable COPD without any cardiac comorbidities compared to bronchial asthma.

Index of Consciousness monitoring may effectively predict and prevent circulatory stress induced by endotracheal intubation under general anesthesia: a prospective randomized controlled trial.

BACKGROUND: The primary objective of anesthesiologists during the induction of anaesthesia is to mitigate the operative stress response resulting from endotracheal intubation. In this prospective, randomized controlled trial, our aim was to assess the feasibility and efficacy of employing Index of Consciousness (IoC, IoC1 and IoC2) monitoring in predicting and mitigating circulatory stress induced by endotracheal intubation for laparoscopic cholecystectomy patients under general anesthesia (GA). METHODS: We enrolled one hundred and twenty patients scheduled for laparoscopic cholecystectomy under GA and randomly allocated them to two groups: IoC monitoring guidance (Group T, n = 60) and bispectral index (BIS) monitoring guidance (Group C, n = 60). The primary endpoints included the heart rate (HR) and mean arterial pressure (MAP) of the patients, as well as the rate of change (ROC) at specific time points during the endotracheal intubation period. Secondary outcomes encompassed the systemic vascular resistance index (SVRI), cardiac output index (CI), stroke volume index (SVI), ROC at specific time points, the incidence of adverse events (AEs), and the induction dosage of remifentanil and propofol during the endotracheal intubation period in both groups. RESULTS: The mean (SD) HR at 1 min after intubation under IoC monitoring guidance was significantly lower than that under BIS monitoring guidance (76 (16) beats/min vs. 82 (16) beats/min, P = 0.049, respectively). Similarly, the mean (SD) MAP at 1 min after intubation under IoC monitoring guidance was lower than that under BIS monitoring guidance (90 (20) mmHg vs. 98 (19) mmHg, P = 0.031, respectively). At each time point from 1 to 5 min after intubation, the number of cases with HR ROC of less than 10% in Group T was significantly higher than in Group C (P < 0.05). Furthermore, between 1 and 3 min and at 5 min post-intubation, the number of cases with HR ROC between 20 to 30% or 40% in Group T was significantly lower than that in Group C (P < 0.05). At 1 min post-intubation, the number of cases with MAP ROC of less than 10% in Group T was significantly higher than that in Group C (P < 0.05), and the number of cases with MAP ROC between 10 to 20% in Group T was significantly lower than that in Group C (P < 0.01). Patients in Group T exhibited superior hemodynamic stability during the peri-endotracheal intubation period compared to those in Group C. There were no significant differences in the frequencies of AEs between the two groups (P > 0.05). CONCLUSION: This promising monitoring technique has the potential to predict the circulatory stress response, thereby reducing the incidence of adverse reactions during the peri-endotracheal intubation period. This technology holds promise for optimizing anesthesia management. TRAIL REGISTRATION:  Chinese Clinical Trail Registry Identifier: ChiCTR2300070237 (20/04/2022).

Deciphering the explanatory potential of blood pressure variables on post-operative length of stay through hierarchical clustering: A retrospective monocentric study.

OBJECTIVE: Mean arterial pressure is widely used as the variable to monitor during anesthesia. But there are many other variables proposed to define intraoperative arterial hypotension. The goal of the present study was to search arterial pressure variables linked with prolonged postoperative length of stay (pLOS). DESIGN: Retrospective cohort study of adult patients having received general anesthesia for a scheduled non-cardiac surgical procedure between 15th July 2017 and 31st December 2019. METHODS: pLOS was defined as a stay longer than the median (main outcome), adjusted for surgery type and duration. 330 arterial pressure variables were analyzed and organized through a clustering approach. An unsupervised hierarchical aggregation method for optimal cluster determination, employing Kendall's tau coefficients and a penalized Bayes information criterion was used. Variables were ranked using the absolute standardized mean distance (aSMD) to measure their effect on pLOS. Finally, after multivariate independence analysis, the number of variables was reduced to three. RESULTS: Our study examined 9,516 patients. When LOS is defined as strictly greater than the median, 34% of patients experienced pLOS. Key arterial pressure variables linked with this definition of pLOS included the difference between the highest and lowest pulse pressure values computed throughout the surgery (aSMD[95%CI] = 0.39[0.31-0.40], p<0.001), the accumulated time pulse pressure above 61mmHg (aSMD = 0.21[0.17-0.25], p<0.001), and the lowest MAP during surgery (aSMD = 0.20[0.16-0.24], p<0.001). CONCLUSIONS: By applying a clustering approach, three arterial pressure variables were associated with pLOS. This scalable method can be applied to various dichotomized outcomes.

Association between average mean arterial pressure and 30-day mortality in critically ill patients with sepsis and primary hypertension: a retrospective analysis.

Sepsis and hypertension pose significant health risks, yet the optimal mean arterial pressure (MAP) target for resuscitation remains uncertain. This study investigates the association between average MAP (a-MAP) within the initial 24 h of intensive care unit admission and clinical outcomes in patients with sepsis and primary hypertension using the Medical Information Mart for Intensive Care (MIMIC) IV database. Multivariable Cox regression assessed the association between a-MAP and 30-day mortality. Kaplan-Meier and log-rank analyses constructed survival curves, while restricted cubic splines (RCS) illustrated the nonlinear relationship between a-MAP and 30-day mortality. Subgroup analyses ensured robustness. The study involved 8,810 patients. Adjusted hazard ratios for 30-day mortality in the T1 group (< 73 mmHg) and T3 group (≥ 80 mmHg) compared to the T2 group (73-80 mmHg) were 1.25 (95% CI 1.09-1.43, P = 0.001) and 1.44 (95% CI 1.25-1.66, P < 0.001), respectively. RCS revealed a U-shaped relationship (non-linearity: P < 0.001). Kaplan-Meier curves demonstrated significant differences (P < 0.0001). Subgroup analysis showed no significant interactions. Maintaining an a-MAP of 73 to 80 mmHg may be associated with a reduction in 30-day mortality. Further validation through prospective randomized controlled trials is warranted.

Intraoperative Mean Arterial Pressure and Postoperative Delayed Graft Function in Kidney Transplantation: Evaluating Three Commonly Used Thresholds.

BACKGROUND: Delayed graft function (DGF) is a common early complication after kidney transplantation (KT) and is associated with various long-term adverse outcomes. Despite numerous studies on hemodynamic management, the optimal hemodynamic goals during KT remain unclear. In this retrospective study, we aimed to investigate if three mean artery pressure (MAP) thresholds (≤75, 80, and 85 mmHg) that were commonly used in clinical practice were associated with DGF in adult patients undergoing KT. METHODS: We extracted de-identified data on adult patients who underwent deceased donor KT from our Discovery Data Repository. DGF was defined as the requirement for dialysis within the first 7 days after transplantation. Three MAP thresholds (≤75, 80, and 85 mmHg) and the duration of pressure below the three thresholds were recorded. Multivariable logistic analysis was used to identify risk factors for DGF. RESULTS: We included 2301 adult KT patients. The mean age was 52.5±12.9 years and 59% were male. DGF occurred in 1066 patients (46.3%). Patients frequently experienced MAP ≤75, 80, and 85 mmHg (approximately 70%, 80%, and 90% of patients experienced 10 min of MAP ≤75, 80, and 85 mmHg, respectively). Patients with DGF spent significantly longer durations below the three MAP thresholds during surgery compared with those without DGF. Further analysis revealed that the minimal time spent on MAP ≤75, 80, and 85 mmHg that were significantly associated with DGF were 6, 23, and 37 min, respectively. After adjusting for non-hemodynamic risk factors (age, basiliximab administration, and urine output), prolonged exposure to the three MAP thresholds remained significant predictors for DGF (for MAP ≤75 mmHg, OR 1.257, 95% CI 1.017-1.554, p = 0.034; MAP ≤80 mmHg, OR 1.220, 95% CI 1.018-1.463, p = 0.031; MAP ≤85 mmHg, OR 1.253, 95% CI 1.048-1.498, p = 0.013). CONCLUSION: Prolonged exposure to the three common MAP thresholds (≤75, 80, and 85 mmHg) occurred frequently during adult deceased donor KT and was associated with DGF.

Efficacy of methylene blue in refractory septic shock: study protocol for a multicenter, randomized, placebo-controlled trial.

BACKGROUND: Septic shock is now the leading cause of mortality in intensive care units (ICUs). Refractory septic shock requires high doses of vasopressors. Some previous studies have revealed that methylene blue could improve hypotension status and help reduce the dosage of catecholamines. This study aims to investigate the clinical effect of methylene blue in septic shock and explore whether it can increase arterial pressure and reduce the usage of vasopressors. METHODS: This study is a multicenter, randomized, placebo-controlled trial planning to include 100 refractory septic shock patients. The protocol is to administer a bolus of 2 mg/kg methylene blue intravenously followed by a continuous infusion of 0.5 mg/kg/h for 48 h. The primary outcome is the total dose of vasopressor required in refractory septic shock in the first 48 h. Secondary outcomes include other hemodynamic parameters, oxygen metabolism indexes, tissue perfusion indexes, major organ function indexes, and certain plasma cytokines and other factors. DISCUSSION: This protocol aims to evaluate the safety and efficacy of methylene blue as adjuvant therapy for refractory septic shock. The main outcome measure will be vasopressor requirements and hemodynamic parameters. Additionally, bedside ultrasonography, blood gases, and cytokines will be assessed to evaluate perfusion, respiratory, and metabolic effects. The results are intended to provide evidence on the safety and efficacy of methylene blue in refractory septic shock, guiding clinical decision-making. TRIAL REGISTRATION: This clinical trial has been registered at ChiCTR ( https://www.chictr.org.cn/ ) on March 16, 2023. ChiCTR registration number: ChiCTR2300069430.

The Respiratory Rate, Age, and Mean Arterial Pressure (RAM) Index: A Novel Prognostic Tool to Predict Mortality among Adult Patients with Acute Heart Failure in the Emergency Department.

Background and Objectives: Acute heart failure (AHF) is a life-threatening condition frequently encountered in the emergency department (ED). Identifying reliable prognostic indicators for in-hospital mortality is crucial for risk stratification and the appropriate management of AHF patients. This study aimed to assess the most effective method for predicting in-hospital mortality among various physiological parameters in patients with AHF presenting to the ED. Additionally, the study evaluated the effectiveness of the RAM index-respiratory rate (RR), age, and mean arterial pressure (MAP)-derived from the shock index (SI) by replacing heart rate with RR, as a novel prognostic tool. This was compared with the SI and its other derivatives to predict in-hospital mortality in adult patients with AHF presenting to the ED. Materials and Methods: This is a retrospective study conducted in the ED of an urban medical center, enrolling adult patients with signs and symptoms of AHF, who met the epidemiological diagnosis criteria, between January 2017 and December 2021. Baseline physiological parameters, including the RR, heart rate, systolic blood pressure, and diastolic blood pressure, were recorded upon ED admission. The RAM index was calculated as the RR multiplied by the age divided by the MAP. Statistical analysis was performed, including univariate analysis, logistic regression, and receiver operating characteristic (ROC) curve analysis. Results: A total of 2333 patients were included in the study. A RAM index > 18.6 (area under ROC curve (AUROC): 0.81; 95% confidence interval (CI): 0.79-0.83) had a superior mortality discrimination ability compared to an SI > 0.77 (AUROC: 0.75; 95% CI: 0.72-0.77), modified shock index > 1.11 (AUROC: 0.75; 95% CI: 0.73-0.77), age shock index > 62.7 (AUROC: 0.74; 95% CI: 0.72-0.76), and age-modified shock index > 79.9 (AUROC: 0.75; 95% CI: 0.73-0.77). A RAM index > 18.6 demonstrated a 7.36-fold higher risk of in-hospital mortality with a sensitivity of 0.80, specificity of 0.68, and negative predictive value of 0.97. Conclusions: The RAM index is an effective tool to predict mortality in AHF patients presenting to the ED. Its superior performance compared to traditional SI-based parameters suggests that the RAM index can aid in risk stratification and the early identification of high-risk patients, facilitating timely and aggressive treatment strategies.

The Association between Percentage of Mean Arterial Pressure and Long-Term Mortality in Acute Myocardial Infarction Patients: An Observational Cohort Study.

Background: Acute myocardial infarction (AMI) is a critical cardiovascular disease with high morbidity and mortality. Identifying practical parameters for predicting long-term mortality is crucial in this patient group. The percentage of mean arterial pressure (%MAP) is a useful parameter used to assess peripheral artery disease. It can be easily calculated from ankle pulse volume recording. Previous studies have shown that %MAP is a useful predictor of all-cause mortality in specific populations, but its relationship with mortality in AMI patients is unclear. Methods: In this observational cohort study, 191 AMI patients were enrolled between November 2003 and September 2004. Ankle-brachial index (ABI) and %MAP were measured using an ABI-form device. All-cause and cardiovascular mortality data were collected from a national registry until December 2018. Cox proportional hazards model and Kaplan-Meier survival plot were used to analyze the association between %MAP and long-term mortality in AMI patients. Results: The median follow-up to mortality was 65 months. There were 130 overall and 36 cardiovascular deaths. High %MAP was associated with increased overall mortality after multivariable analysis (HR = 1.062; 95% CI: 1.017-1.109; p =0.006). However, high % MAP was only associated with cardiovascular mortality in the univariable analysis but became insignificant after the multivariable analysis. Conclusions: In conclusion, this study is the first to evaluate the usefulness of %MAP in predicting long-term mortality in AMI patients. Our study shows that %MAP might be an independent predictor of long-term overall mortality in AMI patients and has better predictive power than ABI.