Evaluation of Vasopressor Exposure and Mortality in Patients With Septic Shock

Blood Pressure Management for Hypotensive Patients in Intensive Care and Perioperative Cardiovascular Settings

Blood pressure is a critical physiological parameter, particularly in the context of cardiac intensive care and perioperative settings. As a primary indicator of organ perfusion, the maintenance of adequate blood pressure is imperative for the assurance of sufficient tissue oxygen delivery. Among critically ill and major surgery patients, the continuous monitoring of blood pressure is performed as a standard practice for patients. Nonetheless, uncertainties remain regarding blood pressure goals, and there is no consensus regarding blood pressure targets. This review describes the determinants of blood pressure, examine the influence of blood pressure on organ perfusion, and synthesize the current clinical evidence from various intensive care and perioperative settings to provide a concise guidance for daily clinical practice.

Noradrenaline dose cutoffs to characterise the severity of cardiovascular failure: Data-based development and external validation

BACKGROUND

The vasopressor dose needed is a common measure to assess the severity of cardiovascular failure, but there is no consensus on the ranges of vasopressor doses determining different levels of cardiovascular support. We aimed to identify cutoffs for determining low, intermediate and high doses of noradrenaline (norepinephrine), the primary vasopressor used in intensive care, based on association with hospital mortality.

METHODS

We conducted a binational registry study to determine cutoffs between low, intermediate and high noradrenaline doses. We required the cutoffs to be statistically rational and practical (rounded to the first decimal and easy to remember), and to result in increasing mortality with increasing doses. The highest noradrenaline dose in the first 24 h after intensive care unit (ICU) admission was used. The cutoffs were developed using data from 8079 ICU patients treated in the ICU at Kuopio University Hospital, Finland, between 2013 and 2019. Subsequently, the cutoffs were validated in the eICU database, including 39,007 ICU admissions to 29 ICUs in the United States of America in 2014-2015. The log-rank statistic, with the Contal and O'Quigley method, was used to determine the cutoffs resulting in the most significant split between the noradrenaline dose groups with regard to hospital mortality.

RESULTS

The two most prominent peaks in the log-rank statistic corresponded to noradrenaline doses 0.20 and 0.44 μg/kg/min. Accordingly, we determined three dose ranges: low (<0.2 μg/kg/min), intermediate (0.2-0.4 μg/kg/min) and high (>0.4 μg/kg/min). Mortality increased, whereas the number of patients decreased consistently with increasing noradrenaline doses in both cohorts. In the development cohort, hospital mortality was 6.5% in the group without noradrenaline administered and 14.0%, 26.4% and 40.2%, respectively, in the low-dose, intermediate-dose and high-dose groups. Compared to patients who received no noradrenaline, the hazard ratio for in-hospital death was 1.4 for the low-dose group, 4.0 for the intermediate-dose group and 7.5 for the high-dose group in the validation cohort (p < .001).

CONCLUSIONS

The highest noradrenaline dose is a useful measure for quantifying circulatory failure. Cutoffs 0.2 and 0.4 μg/kg/min seem to be suitable for defining low, intermediate and high doses.

Efficacy and safety of dynamic arterial elastance for weaning vasopressor support in septic shock patients: a randomised controlled trial protocol

INTRODUCTION

The dynamic arterial elastance (EaDyn), calculated as pulse pressure variation divided by stroke volume variation, has been studied as a predictor of vasopressor weaning. However, its potential as a haemodynamic tool for tapering off vasopressors in patients with sepsis remains unexplored. Therefore, our study aimed to assess whether using EaDyn for weaning vasopressor support could reduce the duration of vasopressor support in patients with sepsis.

METHODS AND ANALYSIS

This pragmatic single-centre controlled clinical trial will take place at Fundación Santa Fe de Bogotá, Colombia. Adult patients diagnosed with septic shock according to the sepsis-3 criteria and a Sequential Organ Failure Assessment score ≥4 will be included. A total of 114 patients (57 per group) will undergo conventional critical care monitoring, and the weaning of vasopressor support will be initiated based on the EaDyn or mean arterial pressure (MAP), depending on the assigned group. EaDyn will be estimated based on the measurements obtained from a PiCCO device connected to a PulsioFlex Monitoring Platform (PULSION Medical Systems SE, Feldkirchen, Germany). Our primary outcome is the difference in vasopressor support duration between the EaDyn and MAP groups.Participants and statisticians performing the statistical analysis will be blinded to the group allocation. Dependent and independent variables will be analysed through univariate and multivariate statistical tests. Since we will perform three repeated measurements for analysis, we will implement a Bonferroni post hoc correction. Additionally, Cox regression and Kaplan-Meier analyses will be conducted to address objectives related to time.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee at Fundación Santa Fe de Bogotá (CCEI-16026-2024). Written informed consent will be obtained from all participants. The results will be disseminated through publication in peer-reviewed journals and presentations at national and international events.

TRIAL REGISTRATION NUMBER

NCT06118775.

Mean arterial pressure to norepinephrine equivalent dose ratio for predicting renal replacement therapy requirement: a retrospective analysis from the MIMIC-IV

BACKGROUND

This study aimed to assess the predictive value of the ratio of mean arterial pressure (MAP) to the corresponding peak rate of norepinephrine equivalent dose (NEQ) within the first day in patients with shock for the subsequent renal replacement therapy (RRT) requirement.

METHODS

Patients were identified using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The relationship was investigated using a restricted cubic spline curve, and propensity score matching(PSM) was used to eliminate differences between groups. Odds ratios (OR) with 95% confidence intervals (CI) were calculated using logistic regression. Variable significance was assessed using extreme gradient boosting (XGBoost), and receiver operating characteristic (ROC) curves were generated.

RESULTS

Of the 5775 patients, 301 (5.2%) received RRT. The MAP/NEQ index showed a declining L-shaped relationship for RRT. After PSM, the adjusted OR per 100 mmHg/mcg/kg/min for RRT was 0.93(95% CI 0.88-0.98). The most influential factors for RRT were fluid balance, baseline creatinine, and the MAP/NEQ index. The threshold for the MAP/NEQ index predicting RRT was 161.7 mmHg/mcg/kg/min (specificity: 65.8%, sensitivity: 74.8%) with an area under the ROC curve of 75.9% (95% CI 73.1-78.8).

CONCLUSIONS

The MAP/NEQ index served as an alternative predictor of RRT necessity based on the NEQ for adult patients who received at least one vasopressor over 6 h within the first 24 h of intensive care unit(ICU) admission. Dynamic modulation of the MAP/NEQ index by the synergistic use of various low-dose vasopressors targeting urine output may be beneficial for exploring individualized optimization of MAP.

Angiotensin ii therapy in refractory septic shock: which patient can benefit most? A narrative review

Patients with septic shock who experience refractory hypotension despite adequate fluid resuscitation and high-dose noradrenaline have high mortality rates. To improve outcomes, evidence-based guidelines recommend starting a second vasopressor, such as vasopressin, if noradrenaline doses exceed 0.5 µg/kg/min. Recently, promising results have been observed in treating refractory hypotension with angiotensin II, which has been shown to increase mean arterial pressure and has been associated with improved outcomes. This narrative review aims to provide an overview of the pathophysiology of the renin-angiotensin system and the role of endogenous angiotensin II in vasodilatory shock with a focus on how angiotensin II treatment impacts clinical outcomes and on identifying the population that may benefit most from its use.

Clozapine-Induced Severe Toxicity: Exploring the Pharmacokinetic Profile of Clozapine and Its Significance in Hemodynamic Instability - A Case Report

Hemodynamic instability in patients with clozapine intoxication can indirectly reflect the serum concentration of clozapine.We have described a case of a 32-year-old pregnant woman who developed life-threatening clozapine toxicity at 28 weeks of gestation. The levels of clozapine and norclozapine in the serum were high. We initiated hemoperfusion(HP) and other detoxification therapies to remove the drug. The patient had severely dilated peripheral blood vessels, which led to cardiac symptoms such as fatal hypotension and uncontrollable tachycardia, resulting in very high cardiac output and elevated Central venous oxygen saturation (ScvO2). Pharmacological intervention significantly improved the hemodynamics.In light of our observations in the ongoing case, we posit that evaluating hemodynamic parameters before and after blood detoxification could serve as a valuable means to gauge effectiveness and provide guidance for treatment.

Diversifying cardiac intensive care unit models: Successful example of an operating surgeon-led unit

Objective

The intensivist-led cardiovascular intensive care unit model is the standard of care in cardiac surgery. This study examines whether a cardiovascular intensive care unit model that uses operating cardiac surgeons, cardiothoracic surgery residents, and advanced practice providers is associated with comparable outcomes.

Methods

This is a single-institution review of the first 400 cardiac surgery patients admitted to an operating surgeon-led cardiovascular intensive care unit from 2020 to 2022. Inclusion criteria are elective status and operations managed by both cardiovascular intensive care unit models (aortic operations, valve operations, coronary operations, septal myectomy). Patients from the surgeon-led cardiovascular intensive care unit were exact matched by operation type and 1:1 propensity score matched with controls from the traditional cardiovascular intensive care unit using a logistic regression model that included age, sex, preoperative mortality risk, incision type, and use of cardiopulmonary bypass and circulatory arrest. Primary outcome was total postoperative length of stay. Secondary outcomes included postoperative intensive care unit length of stay, 30-day mortality, 30-day Society of Thoracic Surgeons-defined morbidity (permanent stroke, renal failure, cardiac reoperation, prolonged intubation, deep sternal infection), packed red cell transfusions, and vasopressor use. Outcomes between the 2 groups were compared using chi-square, Fisher exact test, or 2-sample t test as appropriate.

Results

A total of 400 patients from the surgeon-led cardiovascular intensive care unit (mean age 61.2 ± 12.8 years, 131 female patients [33%], 346 patients [86.5%] with European System for Cardiac Operative Risk Evaluation II <2%) and their matched controls were included. The most common operations across both units were coronary artery bypass grafting (n = 318, 39.8%) and mitral valve repair or replacement (n = 238, 29.8%). Approximately half of the operations were performed via sternotomy (n = 462, 57.8%). There were 3 (0.2%) in-hospital deaths, and 47 patients (5.9%) had a 30-day complication. The total length of stay was significantly shorter for the surgeon-led cardiovascular intensive care unit patients (6.3 vs 7.0 days, P = .028), and intensive care unit length of stay trended in the same direction (2.5 vs 2.9 days, P = .16). Intensive care unit readmission rates, 30-day mortality, and 30-day morbidity were not significantly different between cardiovascular intensive care unit models. The surgeon-led cardiovascular intensive care unit was associated with fewer postoperative red blood cell transfusions in the cardiovascular intensive care unit (P = .002) and decreased vasopressor use (P = .001).

Conclusions

In its first 2 years, the surgeon-led cardiovascular intensive care unit demonstrated comparable outcomes to the traditional cardiovascular intensive care unit with significant improvements in total length of stay, postoperative transfusions in the cardiovascular intensive care unit, and vasopressor use. This early success exemplifies how an operating surgeon-led cardiovascular intensive care unit can provide similar outcomes to the standard-of-care model for patients undergoing elective cardiac surgery.

INITIATION TIMING OF VASOPRESSOR IN PATIENTS WITH SEPTIC SHOCK: A SYSTEMATIC REVIEW AND META-ANALYSIS

ABSTRACT

Background: Vasopressor plays a crucial role in septic shock. However, the time for vasopressor initiation remains controversial. We conducted a systematic review and meta-analysis to explore its initiation timing for septic shock patients. Methods: PubMed, Cochrane Library, Embase, and Web of Sciences were searched from inception to July 12, 2023, for relevant studies. Primary outcome was short-term mortality. Meta-analysis was performed using Stata 15.0. Results: Twenty-three studies were assessed, including 2 randomized controlled trials and 21 cohort studies. The early group resulted in lower short-term mortality than the late group (OR [95% CI] = 0.775 [0.673 to 0.893], P = 0.000, I2 = 67.8%). The significance existed in the norepinephrine and vasopressin in subgroup analysis. No significant difference was considered in the association between each hour's vasopressor delay and mortality (OR [95% CI] = 1.02 [0.99 to 1.051], P = 0.195, I2 = 57.5%). The early group had an earlier achievement of target MAP ( P < 0.001), shorter vasopressor use duration ( P < 0.001), lower serum lactate level at 24 h ( P = 0.003), lower incidence of kidney injury ( P = 0.001), renal replacement therapy use ( P = 0.022), and longer ventilation-free days to 28 days ( P < 0.001). Conclusions: Early initiation of vasopressor (1-6 h within septic shock onset) would be more beneficial to septic shock patients. The conclusion needs to be further validated by more well-designed randomized controlled trials.

Renin-angiotensin-aldosterone system dynamics after targeted blood pressure control using angiotensin II or norepinephrine in cardiac surgery: mechanistic randomised controlled trial

BACKGROUND

The role of the renin-angiotensin-aldosterone axis in vasoplegia after cardiac surgery remains unclear. We tested the hypothesis that, compared with norepinephrine, infusion of angiotensin II titrated to achieve similar mean arterial pressure (MAP) would suppress plasma renin concentration (PRC) while maintaining aldosterone levels.

METHODS

In a double-blind, randomised controlled trial, subjects received either an infusion of angiotensin II or norepinephrine to maintain MAP 70-80 mm Hg from induction of anaesthesia. We compared PRC, aldosterone, dipeptidyl peptidase-3, and angiotensin-converting enzyme 2 activity between treatment groups, before surgery, on ICU admission, and 24 h after surgery.

RESULTS

In 60 patients (11.7% female; mean age 68 yr [11 yr]), norepinephrine increased median PRC at ICU admission (median difference [MD] 46 [inter-quartile range, IQR, 3-88] μU ml-1; P<0.001) but angiotensin II did not (MD -3 [IQR -62 to 35] μU ml-1; P=0.36). Aldosterone levels increased with both. The aldosterone:PRC ratio did not change with norepinephrine (MD -0.01 [IQR -0.14 to 0.03] μU ml-1 per ng dl-1, P=0.76) but increased with angiotensin II (MD 0.05 [IQR 0.004-0.26] μU ml-1 per ng dl-1, P<0.001). The upper quartile of PRC before surgery was associated with higher vasopressor requirements when norepinephrine was used to maintain MAP, but not angiotensin II. Dipeptidyl peptidase-3 levels and angiotensin-converting enzyme 2 activities were similar at all time points.

CONCLUSIONS

Angiotensin II suppressed renin release while maintaining aldosterone levels compared with norepinephrine. Higher plasma renin concentration before surgery was associated with greater vasopressor requirement for norepinephrine, but not angiotensin II.

CLINICAL TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry-ACTRN12621000195853 23/02/2021.

The Effect of Oral Nimodipine on Cerebral Metabolism and Hemodynamic Parameters in Patients Suffering Aneurysmal Subarachnoid Hemorrhage

INTRODUCTION

Nimodipine is routinely administered to aneurysmal subarachnoid hemorrhage patients to improve functional outcomes. Nimodipine can induce marked systemic hypotension, which might impair cerebral perfusion and brain metabolism.

METHODS

Twenty-seven aneurysmal subarachnoid hemorrhage patients having multimodality neuromonitoring and oral nimodipine treatment as standard of care were included in this retrospective study. Alterations in mean arterial blood pressure (MAP), cerebral perfusion pressure (CPP), brain tissue oxygen tension (pbtO2), and brain metabolism (cerebral microdialysis), were investigated up to 120 minutes after oral administration of nimodipine (60 mg or 30 mg), using mixed linear models.

RESULTS

Three thousand four hundred twenty-five oral nimodipine administrations were investigated (126±59 administrations/patient). After 60 mg of oral nimodipine, there was an immediate statistically significant (but clinically irrelevant) drop in MAP (relative change, 0.97; P<0.001) and CPP (relative change: 0.97; P<0.001) compared with baseline, which lasted for the whole 120 minutes observation period (P<0.001). Subsequently, pbtO2 significantly decreased 50 minutes after administration (P=0.04) for the rest of the observation period; the maximum decrease was -0.6 mmHg after 100 minutes (P<0.001). None of the investigated cerebral metabolites (glucose, lactate, pyruvate, lactate/pyruvate ratio, glutamate, glycerol) changed after 60 mg nimodipine. Compared with 60 mg nimodipine, 30 mg induced a lower reduction in MAP (relative change, 1.01; P=0.02) and CPP (relative change, 1.01; P=0.03) but had similar effects on pbtO2 and cerebral metabolism (P>0.05).

CONCLUSIONS

Oral nimodipine reduced MAP, which translated into a reduction in cerebral perfusion and oxygenation. However, these changes are unlikely to be clinically relevant, as the absolute changes were minimal and did not impact cerebral metabolism.

Risk Factors for Weaning Failure in COVID-19 Patients

Background

Data on risk factors associated with mechanical ventilation (MV) weaning failure among SARS-CoV2 ARDS patients is limited. We aimed to determine clinical characteristics associated with weaning outcome in SARS-CoV2 ARDS patients under MV.

Objectives

To determine potential risk factors for weaning outcome in patients with SARS-CoV2 ARDS.

Methods

A retrospective observational study was conducted in the ICUs of four Greek hospitals via review of the electronic medical record for the period 2020-2021. All consecutive adult patients were screened and were included if they fulfilled the following criteria: a) age equal or above 18 years, b) need for MV for more than 48 hours and c) diagnosis of ARDS due to SARS-CoV2 pneumonia or primary or secondary ARDS of other aetiologies. Patient demographic and clinical characteristics were recorded for the first 28 days following ICU admission. The primary outcome was weaning success defined as spontaneous ventilation for more than 48 hours.

Results

A hundred and fifty eight patients were included; 96 SARS-CoV2 ARDS patients. SOFA score, Chronic Obstructive Pulmonary Disease (COPD) and shock were independently associated with the weaning outcome OR(95% CI), 0.86 (0.73-0.99), 0.27 (0.08-0.89) and 0.30 (0.14-0.61), respectively]. When we analysed data from SARS-CoV2 ARDS patients separately, COPD [0.18 (0.03-0.96)] and shock [0.33(0.12 - 0.86)] were independently associated with the weaning outcome.

Conclusions

The presence of COPD and shock are potential risk factors for adverse weaning outcome in SARS-CoV2 ARDS patients.

Tendency of dynamic vasoactive and inotropic medications data as a robust predictor of mortality in patients with septic shock: An analysis of the MIMIC-IV database

Background

Septic shock patients fundamentally require delicate vasoactive and inotropic agent administration, which could be quantitatively and objectively evaluated by the vasoactive–inotropic score (VIS); however, whether the dynamic trends of high-time-resolution VIS alter the clinical outcomes remains unclear. Thus, this study proposes the term VIS Reduction Rate (VRR) to generalise the tendency of dynamic VIS, to explore the association of VRR and mortality for patients with septic shock.

Methods

We applied dynamic and static VIS data to predict ICU mortality by two models: the long short-term memory (LSTM) deep learning model, and the extreme gradient boosting (XGBoost), respectively. The specific target cohort was extracted from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database by the sophisticated structured query language (SQL). Enrolled patients were divided into four groups by VRR value: ≥50%, 0 ~ 50%, −50% ~ 0, and &lt; −50%. Statistical approaches included pairwise propensity score matching (PSM), Cox proportional hazards regression, and two doubly robust estimation models to ensure the robustness of the results. The primary and secondary outcomes were ICU mortality and in-hospital mortality, respectively.

Results

VRR simplifies the dosing trends of vasoactive and inotropic agents represented by dynamic VIS data while requiring fewer data. In total, 8,887 septic shock patients were included. Compared with the VRR ≥50% group, the 0 ~ 50%, −50% ~ 0, and &lt; −50% groups had significantly higher ICU mortality [hazard ratio (HR) 1.32, 95% confidence interval (CI) 1.17–1.50, p &lt; 0.001; HR 1.79, 95% CI 1.44–2.22, p &lt; 0.001; HR 2.07, 95% CI 1.61–2.66, p &lt; 0.001, respectively] and in-hospital mortality [HR 1.43, 95% CI 1.28–1.60, p &lt; 0.001; HR 1.75, 95% CI 1.45–2.11, p &lt; 0.001; HR 2.00, 95% CI 1.61–2.49, p &lt; 0.001, respectively]. Similar findings were observed in two doubly robust estimation models.

Conclusion

The trends of dynamic VIS in ICU might help intensivists to stratify the prognosis of adult patients with septic shock. A lower decline of VIS was remarkably associated with higher ICU and in-hospital mortality among septic shock patients receiving vasoactive–inotropic therapy for more than 24 h.

Evaluate prognostic accuracy of SOFA component score for mortality among adults with sepsis by machine learning method

INTRODUCTION

Sepsis has the characteristics of high incidence, high mortality of ICU patients. Early assessment of disease severity and risk stratification of death in patients with sepsis, and further targeted intervention are very important. The purpose of this study was to develop machine learning models based on sequential organ failure assessment (SOFA) components to early predict in-hospital mortality in ICU patients with sepsis and evaluate model performance.

METHODS

Patients admitted to ICU with sepsis diagnosis were extracted from MIMIC-IV database for retrospective analysis, and were randomly divided into training set and test set in accordance with 2:1. Six variables were included in this study, all of which were from the scores of 6 organ systems in SOFA score. The machine learning model was trained in the training set and evaluated in the validation set. Six machine learning methods including linear regression analysis, least absolute shrinkage and selection operator (LASSO), Logistic regression analysis (LR), Gaussian Naive Bayes (GNB) and support vector machines (SVM) were used to construct the death risk prediction models, and the accuracy, area under the receiver operating characteristic curve (AUROC), Decision Curve Analysis (DCA) and K-fold cross-validation were used to evaluate the prediction performance of developed models.

RESULT

A total of 23,889 patients with sepsis were enrolled, of whom 3659 died in hospital. Three feature variables including renal system score, central nervous system score and cardio vascular system score were used to establish prediction models. The accuracy of the LR, GNB, SVM were 0.851, 0.844 and 0.862, respectively, which were better than linear regression analysis (0.123) and LASSO (0.130). The AUROCs of LR, GNB and SVM were 0.76, 0.76 and 0.67, respectively. K-fold cross validation showed that the average AUROCs of LR, GNB and SVM were 0.757 ± 0.005, 0.762 ± 0.006, 0.630 ± 0.013, respectively. For the probability threshold of 5-50%, LY and GNB models both showed positive net benefits.

CONCLUSION

The two machine learning-based models (LR and GNB models) based on SOFA components can be used to predict in-hospital mortality of septic patients admitted to ICU.

Dynamic Arterial Elastance to Predict Mean Arterial Pressure Decrease after Reduction of Vasopressor in Septic Shock Patients

After fluid status optimization, norepinephrine infusion represents the cornerstone of septic shock treatment. De-escalation of vasopressors should be considered with caution, as hypotension increases the risk of mortality. In this prospective observational study including 42 patients, we assess the role of dynamic elastance (EaDyn), i.e., the ratio between pulse pressure variation and stroke volume variation, which can be measured noninvasively by the MostCare monitoring system, to predict a mean arterial pressure (MAP) drop > 10% 30 min after norepinephrine reduction. Patients were divided into responders (MAP falling > 10%) and non-responders (MAP falling < 10%). The receiver-operating-characteristic curve identified an area under the curve of the EaDyn value to predict a MAP decrease > 10% of 0.84. An EaDyn cut-off of 0.84 predicted a MAP drop > 10% with a sensitivity of 0.71 and a specificity of 0.89. In a multivariate logistic regression, EaDyn was significantly and independently associated with MAP decrease (OR 0.001, 95% confidence interval 0.00001−0.081, p < 0.001). The nomogram model for the probability of MAP decrease > 10% showed a C-index of 0.90. In conclusion, in a septic shock cohort, EaDyn correlates well with the risk of decrease of MAP > 10% after norepinephrine reduction.

Derivation and Validation of Vasoactive Inotrope Score Trajectory Groups in Critically Ill Children With Shock

OBJECTIVES

To determine whether there are clinically relevant and reproducible Vasoactive Inotrope Score (VIS) trajectories in children with shock during the acute phase of critical illness.

DESIGN

Retrospective, observational cohort study.

SETTING

Two tertiary, academic PICUs.

PATIENTS

Children (< 18 yr old) who required vasoactive infusions within 24 hours of admission to the PICU. Those admitted post cardiac surgery were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

An hourly VIS was calculated for the first 72 hours after initiation of vasoactives. Group-based trajectory modeling (GBTM) was applied to a derivation set (75% of encounters) and compared with the trajectories in a validation set (25% of encounters) using the same variables. The primary outcome was in-hospital mortality, and the secondary outcome was multiple organ dysfunction syndrome (MODS) on day 7. A total of 1,828 patients met inclusion criteria, and 309 (16.9%) died. GBTM identified four subgroups that were reproducible in the validation set: "Mild, fast resolving shock" ( n = 853 [47%]; mortality 9%), "Moderate, slow resolving shock" ( n = 422 [23%]; mortality 15%), "Moderate, prolonged shock" ( n = 312 [17%]; mortality 21%), and "Severe, prolonged shock" ( n = 241 [13%]; mortality 40%). There was a significant difference in mortality, MODS on day 7, and suspected infection ( p < 0.001) across groups. The "Mild, fast resolving shock" and "Severe, prolonged shock" groups were identifiable within the first 24 hours. The "Moderate, slow resolving" and "Moderate, prolonged shock" groups were indistinguishable in the first 24 hours after initiation of vasoactives but differed in in-hospital mortality and MODS on day 7. Hydrocortisone administration was independently associated with poor outcomes in the "Mild, fast resolving shock" group.

CONCLUSIONS

We uncovered four distinct and reproducible VIS trajectory groups that were associated with different risk factors, response to therapy, and outcomes in children with shock. Characterizing VIS trajectory groups in the acute phase of critical illness may enable better prognostication and more targeted management.

How can assessing hemodynamics help to assess volume status?

In critically ill patients, fluid infusion is aimed at increasing cardiac output and tissue perfusion. However, it may contribute to fluid overload which may be harmful. Thus, volume status, risks and potential efficacy of fluid administration and/or removal should be carefully evaluated, and monitoring techniques help for this purpose. Central venous pressure is a marker of right ventricular preload. Very low values indicate hypovolemia, while extremely high values suggest fluid harmfulness. The pulmonary artery catheter enables a comprehensive assessment of the hemodynamic profile and is particularly useful for indicating the risk of pulmonary oedema through the pulmonary artery occlusion pressure. Besides cardiac output and preload, transpulmonary thermodilution measures extravascular lung water, which reflects the extent of lung flooding and assesses the risk of fluid infusion. Echocardiography estimates the volume status through intravascular volumes and pressures. Finally, lung ultrasound estimates lung edema. Guided by these variables, the decision to infuse fluid should first consider specific triggers, such as signs of tissue hypoperfusion. Second, benefits and risks of fluid infusion should be weighted. Thereafter, fluid responsiveness should be assessed. Monitoring techniques help for this purpose, especially by providing real time and precise measurements of cardiac output. When decided, fluid resuscitation should be performed through fluid challenges, the effects of which should be assessed through critical endpoints including cardiac output. This comprehensive evaluation of the risk, benefits and efficacy of fluid infusion helps to individualize fluid management, which should be preferred over a fixed restrictive or liberal strategy.

The pharmacotherapeutic options in patients with catecholamine-resistant vasodilatory shock

INTRODUCTION

Septic and vasoplegic shock are common types of vasodilatory shock (VS) with high mortality. After fluid resuscitation and the use of catecholamine-mediated vasopressors (CMV), vasopressin, angiotensin II, methylene blue (MB) and hydroxocobalamin can be added to maintain blood pressure.

AREAS COVERED

VS treatment utilizes a phased approach with secondary vasopressors added to vasopressor agents to maintain an acceptable mean arterial pressure (MAP). This review covers additional vasopressors and adjunctive therapies used when fluid and catecholamine-mediated vasopressors fail to maintain target MAP.

EXPERT OPINION

Evidence supporting additional vasopressor agents in catecholamine resistant VS is limited to case reports, series, and a few randomized control trials (RCTs) to guide recommendations. Vasopressin is the most common agent added next when MAPs are not adequately supported with CMV. VS patients failing fluids and vasopressors with cardiomyopathy may have cardiotonic agents such as dobutamine or milrinone added before or after vasopressin. Angiotensin II, another class of vasopressor is used in VS to maintain adequate MAP. MB and/or hydoxocobalamin, vitamin C, thiamine and corticosteroids are adjunctive therapies used in refractory VS. More RCTs are needed to confirm the utility of these drugs, at what doses, which combinations and in what order they should be given.

Timing of vasoactive agents and corticosteroid initiation in septic shock

Septic shock remains a health care concern associated with significant morbidity and mortality. The Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock recommend early fluid resuscitation and antimicrobials. Beyond initial management, the guidelines do not provide clear recommendations on appropriate time to initiate vasoactive therapies and corticosteroids in patients who develop shock. This review summarizes the literature regarding time of initiation of these interventions. Clinical data regarding time of initiation of these therapies in relation to shock onset, sequence of treatments with regard to each other, and clinical markers evaluated to guide initiation are summarized. Early-high vasopressor initiation within first 6 h of shock onset is associated with lower mortality. Following norepinephrine initiation, the exact dose and timing of escalation to adjunctive vasopressor agents are not well elucidated in the literature. However, recent data indicate that timing may be an important factor in initiating vasopressors and adjunctive therapies, such as corticosteroids. Norepinephrine-equivalent dose and lactate concentration can aid in determining when to initiate vasopressin and angiotensin II in patients with septic shock. Future guidelines with clear recommendations on the time of initiation of septic shock therapies are warranted.

Sepsis triggered oxidative stress-inflammatory axis: the pathobiology of reprogramming in the normal sleep-wake cycle

In individuals with sepsis-related neurodegenerative illness, sleep and circadian rhythm disturbance are common. The alteration in genomic expression linked with the immune-directed oxidative stress-inflammatory axis is thought to cause these individuals' abnormal sleep. On the other hand, sleep is linked to normal brain activity through common neurotransmitter systems and regulatory mechanisms. Ailments (ranging from cognitive to metabolic abnormalities) are seldom related to aberrant sleep that is made worse by sleep disturbance, which throws off the body's sleep-wake cycle. PubMed/Springer link /Public library of science/ScienceDirect/ Mendeley/Medline and Google Scholar were used to find possibly relevant studies. For the literature search, many keywords were considered, both individually and in combination. 'Sepsis,' 'Epidemiology of sepsis,' 'Sepsis-related hyper inflammation,' 'Relationship of sepsis-associated clock gene expression and relationship of inflammation with the reprogramming of genetic alterations' were some of the key terms utilized in the literature search. Our main objective is to understand better how traumatic infections during sepsis affect CNS processes, particularly sleep, by investigating the pathobiology of circadian reprogramming associated with immune-directed oxidative stress-inflammatory pathway responsive gene expression and sleep-wake behaviour in this study.

Sepsis Management, Controversies, and Advancement in Nanotechnology: A Systematic Review

Sepsis is a potentially dangerous infection that requires prompt identification and treatment. Emergency medicine physicians must grasp the clinical signs and laboratory results of direct and indirect organ failure, the source of infection management, and the criteria for treating sepsis and septic shock. The pathogenesis of sepsis is connected to inflammation and an excess of reactive oxygen and nitrogen species, which activate the pathogen-associated molecular pattern (PAMP)-pattern recognition receptor (PRR) and damage-associated molecular pattern (DAMP)-PRR signaling pathways. The development of rapid, sensitive, and precise techniques for sepsis diagnosis might be aided by nanotechnology, a part of nanomedicine. Nanoparticles (NPs) such as magnetic NPs, gold NPs, fluorescent (silica and quantum dots), and lipid-based NPs have all been discussed to contribute to the detection of sepsis-related microbial infections. Because of the intrinsic and unique features of these nano-sized systems, researchers are evaluating nanotechnology-based alternatives for sepsis control. Recent advances in nanotechnology-based technologies for sepsis detection and management are discussed in this study.

Databases (PubMed, Medline, PMC, Google Scholar) were used to source various studies that were carried out on sepsis in terms of assessment, types, diagnosis, and treatment controversies, with more attention being given with a focus on the most recent data, principles, and management guidelines. Priority was also given to studies published within the last 11 years, using keywords such as "sepsis guidelines," "sepsis clinical," "septic risk factors," "sepsis and nano technology," "nano particles," "sepsis controversies," and "nano diagnostic" in the search. After a filtration process, the eight most relevant studies were selected to be included in this review. The filtration process included the use of both inclusion and exclusion criteria. The excluded studies were pediatric populations, obstetrical populations, and nanotechnology advancements dealing with other fields not relating to sepsis. The selected studies were also undertaken through a quality appraisal process using corresponding assessment tools. The selected articles were all highly informative about sepsis and the processes of diagnosis and treatment that are currently in use as well as those that are still being developed or implemented. Furthermore, we look at how nanomedicine in the application of nanomaterials can be employed to efficiently manage sepsis.

Beyond the bundle: Clinical controversies in the management of sepsis in emergency medicine patients

Sepsis is a condition characterized by life-threatening organ dysfunction caused by a dysregulated host response to infection. The emergency department (ED) serves as a crucial entry point for patients presenting with sepsis. Given the heterogeneous presentation and high mortality rate associated with sepsis and septic shock, several clinical controversies have emerged in the management of sepsis. These include the use of novel therapeutic agents like angiotensin II, hydrocortisone, ascorbic acid, thiamine ("HAT") therapy, and levosimendan, Additionally, controversies with current treatments in vasopressor dosing, and the use of and balanced or unbalanced crystalloid are crucial to consider. The purpose of this review is to discuss clinical controversies in the management of septic patients, including the use of novel medications and dosing strategies, to assist providers in appropriately determining what treatment strategy is best suited for patients.

Evaluation of Evidence, Pharmacology, and Interplay of Fluid Resuscitation and Vasoactive Therapy in Sepsis and Septic Shock

ABSTRACT

We sought to review the pharmacology of vasoactive therapy and fluid administration in sepsis and septic shock, with specific insight into the physiologic interplay of these agents. A PubMed/MEDLINE search was conducted using the following terms (vasopressor OR vasoactive OR inotrope) AND (crystalloid OR colloid OR fluid) AND (sepsis) AND (shock OR septic shock) from 1965 to October 2020. A total of 1,022 citations were reviewed with only relevant clinical data extracted. While physiologic rationale provides a hypothetical foundation for interaction between fluid and vasopressor administration, few studies have sought to evaluate the clinical impact of this synergy. Current guidelines are not in alignment with the data available, which suggests a potential benefit from low-dose fluid administration and early vasopressor exposure. Future data must account for the impact of both of these pharmacotherapies when assessing clinical outcomes and should assess personalization of therapy based on the possible interaction.

Optimizing Fluid Resuscitation and Preventing Fluid Overload in Patients with Septic Shock

Intravenous fluid administration remains an important component in the care of patients with septic shock. A common error in the treatment of septic shock is the use of excessive fluid in an effort to overcome both hypovolemia and vasoplegia. While fluids are necessary to help correct the intravascular depletion, vasopressors should be concomitantly administered to address vasoplegia. Excessive fluid administration is associated with worse outcomes in septic shock, so great care should be taken when deciding how much fluid to give these vulnerable patients. Simple or strict "recipes" which mandate an exact amount of fluid to administer, even when weight based, are not associated with better outcomes and therefore should be avoided. Determining the correct amount of fluid requires the clinician to repeatedly assess and consider multiple variables, including the fluid deficit, organ dysfunction, tolerance of additional fluid, and overall trajectory of the shock state. Dynamic indices, often involving the interaction between the cardiovascular and respiratory systems, appear to be superior to traditional static indices such as central venous pressure for assessing fluid responsiveness. Point-of-care ultrasound offers the bedside clinician a multitude of applications which are useful in determining fluid administration in septic shock. In summary, prevention of fluid overload in septic shock patients is extremely important, and requires the careful attention of the entire critical care team.

Should Vasopressors Be Started Early in Septic Shock?

Sepsis can influence blood volume, its distribution, vascular tone, and cardiac function. Persistent hypotension or the need for vasopressors after volume resuscitation is part of the definition of septic shock. Since increased positive fluid balance has been associated with increased morbidity and mortality in sepsis, timing of vasopressors in the treatment of septic shock seems crucial. However, conclusive evidence on timing and sequence of interventions with the goal to restore tissue perfusion is lacking. The aim of this narrative review is to depict the pathophysiology of hypotension in sepsis, evaluate how common interventions to treat hypotension interfere with physiology, and to give a resume of the results from clinical studies focusing on targets and timing of vasopressor in sepsis. The majority of studies comparing early versus late administration of vasopressors in septic shock are rather small, single-center, and retrospective. The range of "early" is between 1 and 12 hours. The available studies suggest a mean arterial pressure of 60 to 65 mm Hg as a threshold for increased risk of morbidity and mortality, whereas higher blood pressure targets do not seem to add further benefits. The data, albeit mostly from observational studies, speak for combining vasopressors with fluids rather "early" in the treatment of septic shock (within a 0-3-hour window). Nevertheless, the optimal resuscitation strategy should take into account the source of infection, the pathophysiology, the time and clinical course preceding the diagnosis of sepsis, and also comorbidities and sepsis-induced organ dysfunction.

[Pharmacological therapy of circulatory shock]

Circulatory shock requires treatment of the underlying pathology in addition to supportive pharmacological therapy that is guided by hemodynamic monitoring. Based on the evaluation of the patient's volume, perfusion and cardiac status, the following therapeutic goals should be achieved: (1) Normalization of the intra- and extravascular fluid volume. (2) Provision of sufficient perfusion pressure and organ perfusion. (3) Optimization of cardiac function including protecting an ischemic and exhausted myocardium from overload. The most important therapeutic substances are balanced electrolyte solutions and the vasopressor noradrenaline. Because there is little scientific evidence for the use of alternative drugs, these should only be given if there is a good pathophysiologic rationale and if their effect is continuously monitored and re-evaluated.

Individualized resuscitation strategy for septic shock formalized by finite mixture modeling and dynamic treatment regimen

BACKGROUND

Septic shock comprises a heterogeneous population, and individualized resuscitation strategy is of vital importance. The study aimed to identify subclasses of septic shock with non-supervised learning algorithms, so as to tailor resuscitation strategy for each class.

METHODS

Patients with septic shock in 25 tertiary care teaching hospitals in China from January 2016 to December 2017 were enrolled in the study. Clinical and laboratory variables were collected on days 0, 1, 2, 3 and 7 after ICU admission. Subclasses of septic shock were identified by both finite mixture modeling and K-means clustering. Individualized fluid volume and norepinephrine dose were estimated using dynamic treatment regime (DTR) model to optimize the final mortality outcome. DTR models were validated in the eICU Collaborative Research Database (eICU-CRD) dataset.

RESULTS

A total of 1437 patients with a mortality rate of 29% were included for analysis. The finite mixture modeling and K-means clustering robustly identified five classes of septic shock. Class 1 (baseline class) accounted for the majority of patients over all days; class 2 (critical class) had the highest severity of illness; class 3 (renal dysfunction) was characterized by renal dysfunction; class 4 (respiratory failure class) was characterized by respiratory failure; and class 5 (mild class) was characterized by the lowest mortality rate (21%). The optimal fluid infusion followed the resuscitation/de-resuscitation phases with initial large volume infusion and late restricted volume infusion. While class 1 transitioned to de-resuscitation phase on day 3, class 3 transitioned on day 1. Classes 1 and 3 might benefit from early use of norepinephrine, and class 2 can benefit from delayed use of norepinephrine while waiting for adequate fluid infusion.

CONCLUSIONS

Septic shock comprises a heterogeneous population that can be robustly classified into five phenotypes. These classes can be easily identified with routine clinical variables and can help to tailor resuscitation strategy in the context of precise medicine.

Hitting the Vasopressor Ceiling: Finding Norepinephrine Associated Mortality in the Critically Ill

BACKGROUND

There is no consensus on what dose of norepinephrine corresponds with futility. The purpose of this study was to investigate the maximum infusion and cumulative doses of norepinephrine associated with survival for patients in medical and surgical intensive care units (MICU and SICU).

MATERIALS AND METHODS

A retrospective review was conducted of 661 critically ill patients admitted to a large academic medical center who received norepinephrine. Univariate, multivariate, and area under the curve analyses with optimal cut offs for maximum infusion rate and cumulative dosage were determined by Youden Index.

RESULTS

The population was 54.9% male, 75.8% white, and 58.7 ± 16.1 y old with 384 (69.8%) admitted to the MICU and 166 (30.2%) admitted to the SICU, including 38 trauma patients. Inflection points in mortality were seen at 18 mcg/min and 17.6 mg. The inflection point was higher in MICU patients at 21 mcg/min and lower in SICU patients at 11 mcg/min. MICU patients also had a higher maximum cumulative dosage of 30.7 mg, compared to 2.7 mg in SICU patients. In trauma patients, norepinephrine infusions up to 5 mcg/min were associated with a 41.7% mortality rate.

CONCLUSION

A maximum rate of 18 mcg/min and cumulative dose of 17.6 mg were the inflection points for mortality risk in ICU patients, with SICU patients tolerating lower doses. In trauma patients, even low doses of norepinephrine were associated with higher mortality. These data suggest that MICU, SICU, and trauma patients differ in need for, response to, and outcome from escalating norepinephrine doses.

Dose-response association between fluid overload and in-hospital mortality in critically ill patients: a multicentre, prospective, observational cohort study

OBJECTIVES

Fluid management is important in ensuring haemodynamic stability in critically ill patients, but can easily lead to fluid overload (FO). However, the optimal fluid balance plot or range for critically ill patients is unknown. This study aimed to explore the dose-response relationship between FO and in-hospital mortality in critically ill patients.

DESIGN

Multicentre, prospective, observational study.

SETTING

Eighteen intensive care units (ICUs) of 16 tertiary hospitals in China.

PARTICIPANTS

Critically ill patients in the ICU for more than 3 days.

PRIMARY OUTCOME MEASURES AND ANALYSES

FO was defined as the ratio of the cumulative fluid balance (L) and initial body weight (kg) on ICU admission, expressed as a percentage. Maximum FO was defined as the peak value of FO during the first 3 days of ICU admission. Logistic regression models with restricted cubic splines were used to explore the pattern and magnitude of the association between maximum FO and risk of in-hospital mortality. Age, sex, Acute Physiology and Chronic Health Evaluation II score, Sequential Organ Failure Assessment score on admission, main diagnosis on admission to ICU, comorbidities, time of maximum FO, mechanical ventilation, renal replacement therapy, use of vasopressors and centres were adjusted in multivariable analysis.

RESULTS

A total of 3850 patients were included in the study, 929 (24.1%) of whom died in the hospital. For each 1% L/kg increase in maximum FO, the risk of in-hospital mortality increased by 4% (adjusted HR (aHR) 1.04, 95% CI 1.03 to 1.05, p<0.001). A maximum FO greater than 10% was associated with a 44% increased HR of in-hospital mortality compared with an FO less than 5% (aHR 1.44, 95% CI 1.27 to 1.67). Notably, we found a non-linear dose-response association between maximum FO and in-hospital mortality.

CONCLUSIONS

Both higher and negative fluid balance levels were associated with an increased risk of in-hospital mortality in critically ill patients.

TRIAL REGISTRATION NUMBER

ChiCTR-ECH-13003934.