Delayed vasopressor initiation is associated with increased mortality in patients with septic shock

Prognostic evaluation of the norepinephrine equivalent score and the vasoactive-inotropic score in patients with sepsis and septic shock: a retrospective cohort study

Background

This study investigated the association between vasoactive medication exposure and mortality risk in patients with sepsis using the norepinephrine equivalent (NEE) score and vasoactive-inotropic score (VIS).

Methods

This retrospective cohort study included adult patients with sepsis requiring vasoactive agents. The data were extracted from the Medical Information Mart for Intensive Care IV database. The primary outcome was 28-day mortality. Multivariate Cox regression was used to elucidate the relationship between vasoactive medication exposure and 28-day mortality, as quantified by the VIS and NEE score. Hazard ratios with 95% confidence intervals (CI) for 28-day mortality were generated, and forest plots were constructed to present the results of univariate and multivariate analyses. The Kaplan-Meier method was used to analyze the cumulative incidence of 28-day mortality. A nomogram was constructed to predict the prognosis of patients with sepsis.

Results

The present study encompassed 9,032 patients diagnosed with sepsis who received vasoactive therapy, of which 4,229 patients were further analyzed at the second hour after the onset of sepsis. Distinct variations in demographic data were observed between survivors (n = 3,265, 77.21%) and non-survivors (n = 964, 22.79%). Multivariate analysis indicated that several factors, including VIS >15.04 (p = 0.001), NEE >0.10 (p < 0.001), heart rate (p = 0.045), mean arterial pressure (p = 0.009), respiratory rate (p < 0.001), oxygen saturation (p < 0.001), blood urea nitrogen (BUN) (p = 0.001), and the Acute Physiology and Chronic Health Evaluation II (p < 0.001), were significantly associated with 28-day mortality in the patients with sepsis. The NEE score, respiratory rate, oxygen saturation, and BUN were incorporated into the nomogram model with a concordance index of 0.779 and an area under the curve of 0.802 (95% CI 0.787-0.818).

Conclusion

We found that the VIS and NEE score had favorable values for predicting mortality risk in patients with sepsis in the intensive care units. The VIS and NEE score in the second hour after sepsis onset were independently associated with 28-day mortality in patients with sepsis.

Comparison of Early and Late Norepinephrine Administration in Patients with Septic Shock: A Systematic Review and Meta-analysis

BACKGROUND

Vasopressor administration at an appropriate time is crucial, but the optimal timing remains controversial.

RESEARCH QUESTION

Does early vs late norepinephrine administration impact the prognosis of septic shock?

STUDY DESIGN AND METHODS

Searches were conducted on PubMed, EMBASE, the Cochrane Library, and KMBASE. We included studies of adults with sepsis and categorized patients into an early and late norepinephrine group according to specific time points or differences in norepinephrine use protocols. The primary outcome was overall mortality. The secondary outcomes included length of stay in the ICU, days free from ventilator use, days free from renal replacement therapy, days free from vasopressor use, adverse events, and total fluid volume.

RESULTS

Twelve studies (four randomized controlled trials [RCTs] and eight observational studies) comprising 7,281 patients were analyzed. For overall mortality, no significant difference was found between the early norepinephrine group and late norepinephrine group in RCTs (OR, 0.70; 95% CI, 0.41-1.19) or observational studies (OR, 0.83; 95% CI, 0.54-1.29). In the two RCTs without a restrictive fluid strategy that prioritized vasopressors and lower IV fluid volumes, the early norepinephrine group showed significantly lower mortality than the late norepinephrine group (OR, 0.49; 95%, CI, 0.25-0.96). The early norepinephrine group demonstrated more mechanical ventilator-free days in observational studies (mean difference, 4.06; 95% CI, 2.82-5.30). The incidence of pulmonary edema was lower in the early norepinephrine group in the three RCTs that reported this outcome (OR, 0.43; 95% CI, 0.25-0.74). No differences were found in the other secondary outcomes.

INTERPRETATION

Overall mortality did not differ significantly between early and late norepinephrine administration for septic shock. However, early norepinephrine administration seemed to reduce pulmonary edema incidence, and mortality improvement was observed in studies without fluid restriction interventions, favoring early norepinephrine use.

Improvement in ICU Mortality From Sepsis Associated With Recuperation From Septic Multiple-Organ Failure: A Retrospective, Single-Center, Cohort Study

BACKGROUND

Although mortality due to sepsis has decreased in recent decades, there are few studies on the timing of death during ICU stay. Characteristics of patients related to changes over the years of ICU death and changes in the timing of ICU death will provide new insights for future sepsis management.

METHODS

This was a single-center, retrospective study. Patients admitted to the ICU for sepsis between 2005 and 2019 were included in the study. The study period was divided into three five-year intervals, and the timing of death in the ICU was divided into early-stage (1-3 ICU days), mid-stage (4-14 ICU days), and late-stage (15 or more ICU days). Patient characteristics related to ICU death at three five-year intervals and the timing of death were evaluated.

RESULTS

ICU mortality for sepsis has decreased over time (2005-2009, 30.2%; 2010-2014, 21.0%; 2015-2019, 12.1%; p<0.01). In the timing of death, only mid-stage mortality decreased. Multiple-organ failure (OR, 4.53; 95% CI, 2.79-7.48) and hematological malignancies (OR, 2.48; 95% CI, 1.19-5.07) were associated with ICU mortality over entire study periods. Only multiple-organ failure was associated with ICU mortality at the five-year intervals (OR, 5.94; 95% CI, 2.73-13.7 for 2005-2009; OR, 4.01; 95% CI, 1.82-9.31 for 2010-2014; OR, 2.58; 95% CI, 1.05-6.59 for 2015-2019). Mid-stage mortality of multiple-organ failure decreased (2005-2009, 12.8%; 2010-2014, 7.6%; 2015-2019, 1.6%; p=0.02). However, early- and late-stage mortality of multiple-organ failure did not change.

CONCLUSIONS

Improvement in mid-stage mortality in septic patients with multiple-organ failure can contribute to the improvement of overall ICU mortality in patients with sepsis.

Fluid Resuscitation and Sepsis Management in Patients with Chronic Kidney Disease or End-Stage Renal Disease: Scoping Review

Managing sepsis and fluid resuscitation in patients with chronic kidney disease or end-stage renal disease is challenging for health care providers. Nurses are essential for early identification and treatment of these patients. Nurse education on assessing perfusion and implementing 3-hour bundled care can improve mortality rates in patients with sepsis. In this scoping review, initial screening identified 1176 articles published from 2015 through 2023 in the National Library of Medicine database; 29 articles were included in the literature summary and evidence synthesis. A systematic review meta-analysis was not possible because of data heterogeneity. The review revealed that most patients with chronic kidney disease or end-stage renal disease received more conservative resuscitation than did the general population, most likely because of concerns about volume overload. However, patients with chronic kidney disease or end-stage renal disease could tolerate the standard initial fluid resuscitation bolus of 30 mL/kg for sepsis. Outcomes in patients with chronic kidney disease or end-stage renal disease were similar to outcomes in patients without those conditions, whether they received standard or conservative fluid resuscitation. Patients who received the standard (higher) fluid resuscitation volume did not have increased rates of complications such as longer duration of mechanical ventilation, increased mortality, or prolonged length of stay. Using fluid responsiveness to guide resuscitation was associated with improved outcomes. The standard initial fluid resuscitation bolus of 30 mL/kg may be safe for patients with chronic kidney disease or end-stage renal disease and sepsis. Fluid responsiveness could be a valuable resuscitation criterion, promoting better decision-making by multidisciplinary teams. Further research is required.

A Delphi Process to Identify Relevant Outcomes That May Be Associated With a Predictive Analytic Tool to Detect Hemodynamic Deterioration in the Intensive Care Unit

Background The critical care literature has seen an increase in the development and validation of tools using artificial intelligence for early detection of patient events or disease onset in the intensive care unit (ICU). The hemodynamic stability index (HSI) was found to have an AUC of 0.82 in predicting the need for hemodynamic intervention in the ICU. Future studies using this tool may benefit from targeting those outcomes that are more relevant to clinicians and most achievable. Methods A three-round Delphi study was conducted with a panel of 10 critical care physicians and three nurses in the United States to identify outcomes that may be most relevant and achievable with the HSI when evaluated for use in the ICU. To achieve criteria for relevance, at least 65% of panelists had to rate an outcome as a 4 or 5 on a 5-point scale. Results Nineteen of 24 outcomes that may be associated with the HSI achieved consensus for relevance. The Kemeny-Young approach was used to develop a matrix depicting the distribution of outcomes considering both relevance and achievability. "Reduces time spent in hemodynamic instability" and "reduces times to recognition of hemodynamic instability" were the highest-ranking outcomes considering both relevance and achievability. Conclusion This Delphi study was a feasible method to identify relevant outcomes that may be associated with an appropriate predictive analytic tool in the ICU. These findings can provide insight to researchers looking to study such tools to impact outcomes relevant to critical care practitioners. Future studies should test these tools in the ICU that target the most clinically relevant and achievable outcomes, such as time spent hemodynamically unstable or time until actionable nursing assessment or treatment.

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.

Vasopressin in Sepsis and Other Shock States: State of the Art

This review of the use of vasopressin aims to be comprehensive and highly practical, based on the available scientific evidence and our extensive clinical experience with the drug. It summarizes controversies about vasopressin use in septic shock and other vasodilatory states. Vasopressin is a natural hormone with powerful vasoconstrictive effects and is responsible for the regulation of plasma osmolality by maintaining fluid homeostasis. Septic shock is defined by the need for vasopressors to correct hypotension and lactic acidosis secondary to infection, with a high mortality rate. The Surviving Sepsis Campaign guidelines recommend vasopressin as a second-line vasopressor, added to norepinephrine. However, these guidelines do not address specific debates surrounding the use of vasopressin in real-world clinical practice.

Identification and Prediction of Clinical Phenotypes in Hospitalized Patients With COVID-19: Machine Learning From Medical Records

BACKGROUND

There is significant heterogeneity in disease progression among hospitalized patients with COVID-19. The pathogenesis of SARS-CoV-2 infection is attributed to a complex interplay between virus and host immune response that in some patients unpredictably and rapidly leads to "hyperinflammation" associated with increased risk of mortality. The early identification of patients at risk of progression to hyperinflammation may help inform timely therapeutic decisions and lead to improved outcomes.

OBJECTIVE

The primary objective of this study was to use machine learning to reproducibly identify specific risk-stratifying clinical phenotypes across hospitalized patients with COVID-19 and compare treatment response characteristics and outcomes. A secondary objective was to derive a predictive phenotype classification model using routinely available early encounter data that may be useful in informing optimal COVID-19 bedside clinical management.

METHODS

This was a retrospective analysis of electronic health record data of adult patients (N=4379) who were admitted to a Johns Hopkins Health System hospital for COVID-19 treatment from 2020 to 2021. Phenotypes were identified by clustering 38 routine clinical observations recorded during inpatient care. To examine the reproducibility and validity of the derived phenotypes, patient data were randomly divided into 2 cohorts, and clustering analysis was performed independently for each cohort. A predictive phenotype classifier using the gradient-boosting machine method was derived using routine clinical observations recorded during the first 6 hours following admission.

RESULTS

A total of 2 phenotypes (designated as phenotype 1 and phenotype 2) were identified in patients admitted for COVID-19 in both the training and validation cohorts with similar distributions of features, correlations with biomarkers, treatments, comorbidities, and outcomes. In both the training and validation cohorts, phenotype-2 patients were older; had elevated markers of inflammation; and were at an increased risk of requiring intensive care unit-level care, developing sepsis, and mortality compared with phenotype-1 patients. The gradient-boosting machine phenotype prediction model yielded an area under the curve of 0.89 and a positive predictive value of 0.83.

CONCLUSIONS

Using machine learning clustering, we identified and internally validated 2 clinical COVID-19 phenotypes with distinct treatment or response characteristics consistent with similar 2-phenotype models derived from other hospitalized populations with COVID-19, supporting the reliability and generalizability of these findings. COVID-19 phenotypes can be accurately identified using machine learning models based on readily available early encounter clinical data. A phenotype prediction model based on early encounter data may be clinically useful for timely bedside risk stratification and treatment personalization.

Should we initiate vasopressors earlier in patients with septic shock: A mini systemic review

Septic shock treatment remains a major challenge for intensive care units, despite the recent prominent advances in both management and outcomes. Vasopressors serve as a cornerstone of septic shock therapy, but there is still controversy over the timing of administration. Specifically, it remains unclear whether vasopressors should be used early in the course of treatment. Here, we provide a systematic review of the literature on the timing of vasopressor administration. Research was systematically identified through PubMed, Embase and Cochrane searching according to PRISMA guidelines. Fourteen studies met the eligibility criteria and were included in the review. The pathophysiological basis for early vasopressor use was classified, with the exploration on indications for the early administration of mono-vasopressors or their combination with vasopressin or angiotensinII. We found that mortality was 28.1%-47.7% in the early vasopressors group, and 33.6%-54.5% in the control group. We also investigated the issue of vasopressor responsiveness. Furthermore, we acknowledged the subsequent challenge of administration of high-dose norepinephrine via peripheral veins with early vasopressor use. Based on the literature review, we propose a possible protocol for the early initiation of vasopressors in septic shock resuscitation.

Early administration of multiple vasopressors is associated with better survival in patients with sepsis: a propensity score-weighted study

BACKGROUND

The association between the timing of administration of multiple vasopressors and patient outcomes has not been investigated.

METHODS

This study used data from the MIMIC-IV database. Patients with sepsis who were administered two or more vasopressors were included. The principal exposure was the last norepinephrine dose when adding a second vasopressor. The cohort was divided into early (last norepinephrine dose < 0.25 μg/kg/min) and normal (last norepinephrine dose ≥ 0.25 μg/kg/min) groups. The primary outcome was 28-day mortality. Multivariable Cox analyses, propensity score matching, stabilized inverse probability of treatment weighting (sIPTW), and restricted cubic spline (RCS) curves were used.

RESULTS

Overall, 1,437 patients who received multiple vasopressors were included. Patients in the early group had lower 28-day mortality (HR: 0.76; 95% CI: 0.65-0.89; p < 0.001) than those in the single group, with similar results in the propensity score-matched (HR: 0.80; 95% CI: 0.68-0.94; p = 0.006) and sIPTW (HR: 0.75; 95% CI: 0.63-0.88; p < 0.001) cohorts. RCS curves showed that the risk of 28-day mortality increased as the last norepinephrine dose increased.

CONCLUSIONS

The timing of secondary vasopressor administration is strongly associated with the outcomes of patients with sepsis.

Fluids and Early Vasopressors in the Management of Septic Shock: Do We Have the Right Answers Yet?

Septic shock is a common condition associated with hypotension and organ dysfunction. It is associated with high mortality rates of up to 60% despite the best recommended resuscitation strategies in international guidelines. Patients with septic shock generally have a Mean Arterial Pressure below 65 mmHg and hypotension is the most important determinant of mortality among this group of patients. The extent and duration of hypotension are important. The two initial options that we have are 1) administration of intravenous (IV) fluids and 2) vasopressors, The current recommendation of the Surviving Sepsis Campaign guidelines to administer 30 ml/kg fluid cannot be applied to all patients. Complications of fluid over-resuscitation further delay organ recovery, prolong ICU and hospital length of stay, and increase mortality. The only reason for administering intravenous fluids in a patient with circulatory shock is to increase the mean systemic filling pressure in a patient who is volume-responsive, such that cardiac output also increases. The use of vasopressors seems to be a more appropriate strategy, the very early administration of vasopressors, preferably during the first hour after diagnosis of septic shock, may have a multimodal action and potential advantages, leading to lower morbidity and mortality in the management of septic patients. Vasopressor therapy should be initiated as soon as possible in patients with septic shock.

DEVELOPMENT OF SCORE SYSTEM BASED ON POINT-OF-CARE ULTRASOUND TO PREDICT VASOPRESSOR REQUIREMENT FOR EMERGENCY PATIENTS WITH CARDIOPULMONARY SYMPTOMS

ABSTRACT

Objectives : Patients with cardiopulmonary symptoms admitted to the emergency department (ED) have high mortality and intensive care unit admission rates. We developed a new scoring system comprising concise triage information, point-of-care ultrasound, and lactate levels to predict vasopressor requirements. Methods : This retrospective observational study was conducted at a tertiary academic hospital. Patients with cardiopulmonary symptoms who visited the ED and underwent point-of-care ultrasound between January 2018 and December 2021 were enrolled. The influence of demographic and clinical findings on the requirement for vasopressor support within 24 h of ED admission was investigated. A new scoring system was developed using key components after stepwise multivariable logistic regression analysis. Prediction performance was evaluated using the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Results : A total of 2,057 patients were analyzed. A stepwise multivariable logistic regression model showed high predictive performance in the validation cohort (AUC, 0.87). Eight key components were selected: hypotension, chief complaint, and fever at ED admission, and way of ED visit, systolic dysfunction, regional wall motion abnormalities, inferior vena cava status, and serum lactate level. The scoring system was developed based on the β coefficients of each component: accuracy, 0.8079; sensitivity, 0.8057; specificity, 0.8214; PPV, 0.9658; and NPV, 0.4035, with a cutoff value according to the Youden index. Conclusions : A new scoring system was developed to predict vasopressor requirements in adult ED patients with cardiopulmonary symptoms. This system can serve as a decision-support tool to guide efficient assignment of emergency medical resources.

Prediction prolonged mechanical ventilation in trauma patients of the intensive care unit according to initial medical factors: a machine learning approach

The goal of this study was to develop a predictive machine learning model to predict the risk of prolonged mechanical ventilation (PMV) in patients admitted to the intensive care unit (ICU), with a focus on laboratory and Arterial Blood Gas (ABG) data. This retrospective cohort study included ICU patients admitted to Rajaei Hospital in Shiraz between 2016 and March 20, 2022. All adult patients requiring mechanical ventilation and seeking ICU admission had their data analyzed. Six models were created in this study using five machine learning models (PMV more than 3, 5, 7, 10, 14, and 23 days). Patients' demographic characteristics, Apache II, laboratory information, ABG, and comorbidity were predictors. This study used Logistic regression (LR), artificial neural networks (ANN), support vector machines (SVM), random forest (RF), and C.5 decision tree (C.5 DT) to predict PMV. The study enrolled 1138 eligible patients, excluding brain-dead patients and those without mechanical ventilation or a tracheostomy. The model PMV > 14 days showed the best performance (Accuracy: 83.63-98.54). The essential ABG variables in our two optimal models (artificial neural network and decision tree) in the PMV > 14 models include FiO₂, paCO₂, and paO₂. This study provides evidence that machine learning methods outperform traditional methods and offer a perspective for achieving a consensus definition of PMV. It also introduces ABG and laboratory information as the two most important variables for predicting PMV. Therefore, there is significant value in deploying such models in clinical practice and making them accessible to clinicians to support their decision-making.

What the Joint Commission Medication Management Titration Standards Mean to Quality Care for Complex Patients

ABSTRACT

The Joint Commission (TJC), the nation's largest healthcare accreditor, was founded in the 1950s. Its Standards for Medication Management (MM) of titratable medications focused on prescriptive ordering practices versus reliance on nurse clinical decision making. The use of measurable endpoints to guide nurse decision making regarding medication titration has been the standard of care since the inception of TJC. Evidence to support altering these practice patterns is lacking. Using the 6 aims for the healthcare system (safe, timely, effective, efficient, equitable, and patient-centered) from the National Academy of Medicine, formerly the Institute of Medicine, and the American Association of Critical-Care Nurses Healthy Work Environment essential standards (skilled communication, true collaboration, effective decision making, appropriate staffing, meaningful recognition, authentic leadership), this article examines the impact of TJC MM standards on system design in critical care environments.

Influence of time from admission to norepinephrine administration and volume of fluids received on outcomes of patients meeting sepsis-3 criteria: a retrospective study using the MIMIC-IV database

Objectives

Vasopressors are a cornerstone in the management of sepsis, marked by distributive shock often unresponsive to fluid resuscitation. Prior research and clinician surveys have suggested that earlier usage of vasopressors corresponds to improved outcomes.

Methods

A retrospective cohort was constructed using patient data contained within the Medical Information Mart for Intensive Care-IV database. Analytic cohort included a total of 2079 patients meeting sepsis-3 criteria with a ≥2-point rise in Sequential Organ Failure Assessment score and administered norepinephrine (NE) as first-line vasopressor within 24 hours of admission to the intensive care unit (ICU). Patients receiving other vasopressors or missing documented fluid resuscitation information were excluded. Primary end points included mortality, use of invasive mechanical ventilation and length of stay which were analyzed in a multivariate logistic regression model for the primary effect of time from ICU admission to NE administration using covariates.

Results

Time to NE use was defined as either early, using <6 hours from time of ICU admission or late using >6 hours to ≤24 hours. Patients who received early NE had significantly lower adjusted odds of mortality (0.75, 95% CI 0.57 to 0.97, p=0.026), higher adjusted odds of invasive mechanical ventilation (1.48, 95% CI 1.01 to 2.16, p=0.045), no significant difference in hospital length of stay (difference in days 0.6 (95% CI -3.24 to 2.04)) and lower ICU length of stay (difference in days -0.9 (95% CI -1.74 to -0.01)), as compared with the late NE group.

Conclusion

Among patients admitted to the ICU for sepsis, early use of NE was associated with significantly lower odds of mortality but higher odds of mechanical ventilation, and no significant difference in length of hospital stay but less time in the ICU. Furthermore, the volume of fluids received prior to NE use may have a significant impact on optimal NE timing.

Level of evidence

Level IV-therapeutic care/management.

External validation of a machine learning model to predict hemodynamic instability in intensive care unit

Background

Early prediction model of hemodynamic instability has the potential to improve the critical care, whereas limited external validation on the generalizability. We aimed to independently validate the Hemodynamic Stability Index (HSI), a multi-parameter machine learning model, in predicting hemodynamic instability in Asian patients.

Method

Hemodynamic instability was marked by using inotropic, vasopressor, significant fluid therapy, and/or blood transfusions. This retrospective study included among 15,967 ICU patients who aged 20 years or older (not included 20 years) and stayed in ICU for more than 6 h admitted to Taipei Veteran General Hospital (TPEVGH) between January 1, 2010, and March 31, 2020, of whom hemodynamic instability occurred in 3053 patients (prevalence = 19%). These patients in unstable group received at least one intervention during their ICU stays, and the HSI score of both stable and unstable group was calculated in every hour before intervention. The model performance was assessed using the area under the receiver operating characteristic curve (AUROC) and was compared to single indicators like systolic blood pressure (SBP) and shock index. The hemodynamic instability alarm was set by selecting optimal threshold with high sensitivity, acceptable specificity, and lead time before intervention was calculated to indicate when patients were firstly identified as high risk of hemodynamic instability.

Results

The AUROC of HSI was 0.76 (95% CI, 0.75–0.77), which performed significantly better than shock Index (0.7; 95% CI, 0.69–0.71) and SBP (0.69; 95% CI, 0.68–0.70). By selecting 0.7 as a threshold, HSI predicted 72% of all 3053 patients who received hemodynamic interventions with 67% in specificity. Time-varying results also showed that HSI score significantly outperformed single indicators even up to 24 h before intervention. And 95% unstable patients can be identified more than 5 h in advance.

Conclusions

The HSI has acceptable discrimination but underestimates the risk of stable patients in predicting the onset of hemodynamic instability in an external cohort.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04088-9.

Economic Evaluation of Ultrasound-guided Central Venous Catheter Confirmation vs Chest Radiography in Critically Ill Patients: A Labor Cost Model

INTRODUCTION

Despite evidence suggesting that point-of-care ultrasound (POCUS) is faster and non-inferior for confirming position and excluding pneumothorax after central venous catheter (CVC) placement compared to traditional radiography, millions of chest radiographs (CXR) are performed annually for this purpose. Whether the use of POCUS results in cost savings compared to CXR is less clear but could represent a relative advantage in implementation efforts. Our objective in this study was to evaluate the labor cost difference for POCUS-guided vs CXR-guided CVC position confirmation practices.

METHODS

We developed a model to evaluate the per patient difference in labor cost between POCUS-guided vs CXR-guided CVC confirmation at our local urban, tertiary academic institution. We used internal cost data from our institution to populate the variables in our model.

RESULTS

The estimated labor cost per patient was $18.48 using CXR compared to $14.66 for POCUS, resulting in a net direct cost savings of $3.82 (21%) per patient using POCUS for CVC confirmation.

CONCLUSION

In this study comparing the labor costs of two approaches for CVC confirmation, the more efficient alternative (POCUS-guided) is not more expensive than traditional CXR. Performing an economic analysis framed in terms of labor costs and work efficiency may influence stakeholders and facilitate earlier adoption of POCUS for CVC confirmation.

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.

Assessment of Dynamic Changes in Stressed Volume and Venous Return during Hyperdynamic Septic Shock

The present work investigated the dynamic changes in stressed volume (Vs) and other determinants of venous return using a porcine model of hyperdynamic septic shock. Septicemia was induced in 10 anesthetized swine, and fluid challenges were started after the diagnosis of sepsis-induced arterial hypotension and/or tissue hypoperfusion. Norepinephrine infusion targeting a mean arterial pressure (MAP) of 65 mmHg was started after three consecutive fluid challenges. After septic shock was confirmed, norepinephrine infusion was discontinued, and the animals were left untreated until cardiac arrest occurred. Baseline Vs decreased by 7% for each mmHg decrease in MAP during progression of septic shock. Mean circulatory filling pressure (Pmcf) analogue (Pmca), right atrial pressure, resistance to venous return, and efficiency of the heart decreased with time (p < 0.001 for all). Fluid challenges did not improve hemodynamics, but noradrenaline increased Vs from 107 mL to 257 mL (140%) and MAP from 45 mmHg to 66 mmHg (47%). Baseline Pmca and post-cardiac arrest Pmcf did not differ significantly (14.3 ± 1.23 mmHg vs. 14.75 ± 1.5 mmHg, p = 0.24), but the difference between pre-arrest Pmca and post-cardiac arrest Pmcf was statistically significant (9.5 ± 0.57 mmHg vs. 14.75 ± 1.5 mmHg, p < 0.001). In conclusion, the baseline Vs decreased by 7% for each mmHg decrease in MAP during progression of hyperdynamic septic shock. Significant changes were also observed in other determinants of venous return. A new physiological intravascular volume existing at zero transmural distending pressure was identified, termed as the rest volume (Vr).

[Resuscitation strategy for patients with sepsis and septic shock]

Fluid and vasopressor resuscitation is, along with antimicrobial therapy and control of the focus of infection, a basic issue of the treatment of sepsis and septic shock. There is currently no accepted protocol that we can follow for the resuscitation of these patients and the Surviving Sepsis Campaign proposes controversial measures and without sufficient evidence support to establish firm recommendations. We propose a resuscitation strategy adapted to the situation of each patient: in the patient in whom community sepsis is suspected, we consider that the early administration of 30mL/kg of crystalloids is effective and safe; in the patient with nosocomial sepsis, we must carry out a more in-depth evaluation before initiating aggressive resuscitation. In patients who do not respond to initial resuscitation, it is necessary to increase monitoring level and, depending on the hemodynamic profile, administer more fluids, a second vasopressor or inotropes.

[Vasoactive drugs in the treatment of septic shock]

Septic shock is a high mortality complication frequently associated with sepsis. Early initiation of vasopressor treatment, even before completion of initial fluid resuscitation, is a determining factor in prognosis. In this sense, norepinephrine continues to be the drug of first choice, although there is increasing evidence of benefit combining it with other non-adrenergic drugs, such as vasopressin, instead of escalating norepinephrine doses. The pathophysiology of septic shock is multifactorial, and sometimes is associated with a situation of myocardial dysfunction that contributes to hemodynamic instability. It is essential to identify this situation since it worsens the prognosis and may benefit from combined treatment with inotropic drugs. There are novel vasoactive agents under study, more selective than the classic ones that in a next future could help to design more individualized and precise treatments. In the present work, the current knowledge about vasoactive drugs and their use in the management of septic shock is summarized according to the most recent scientific evidence.

Vasopressor Choice and Timing in Vasodilatory Shock

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2022. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2022 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .

Current practice and evolving concepts in septic shock resuscitation

Clinical and pathophysiological understanding of septic shock has progressed exponentially in the previous decades, translating into a steady decrease in septic shock-related morbidity and mortality. Even though large randomized, controlled trials have addressed fundamental aspects of septic shock resuscitation, many questions still exist. In this review, we will describe the current standards of septic shock resuscitation, but the emphasis will be placed on evolving concepts in different domains such as clinical resuscitation targets, adequate use of fluids and vasoactive drugs, refractory shock, and the use of extracorporeal therapies. Multiple research opportunities remain open, and collaborative endeavors should be performed to fill in these gaps.

Major Publications in the Critical Care Pharmacotherapy Literature: 2020

OBJECTIVES

To summarize selected meta-analyses and trials related to critical care pharmacotherapy published in 2020.

DATA SOURCES

The Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update group screened 36 journals monthly for impactful publications.

STUDY SELECTION

The group reviewed a total of 119 articles during 2020 according to relevance for practice.

DATA EXTRACTION

Articles were selected with consensus and importance to clinical practice from those included in the monthly Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update. The group reviewed articles according to Grading of Recommendations, Assessment, Development, and Evaluations criteria. Articles with a 1A grade were selected.

DATA SYNTHESIS

Several trials were summarized, including two meta-analyses and five original research trials. Original research trials evaluating vitamin C, hydrocortisone, and thiamine versus hydrocortisone in sepsis, the use of nonsedation strategies, dexmedetomidine in cardiac surgery, remdesivir for severe acute respiratory syndrome coronavirus 2, and thrombectomy in acute ischemic stroke. Two meta-analyses determining the impact of norepinephrine initiation in patients with septic shock and the use of corticosteroids in severe acute respiratory syndrome coronavirus 2 was included.

CONCLUSIONS

This clinical review provides summary and perspectives of clinical practice impact on influential critical care pharmacotherapy publications in 2020.

Early prediction of hemodynamic interventions in the intensive care unit using machine learning

Background

Timely recognition of hemodynamic instability in critically ill patients enables increased vigilance and early treatment opportunities. We develop the Hemodynamic Stability Index (HSI), which highlights situational awareness of possible hemodynamic instability occurring at the bedside and to prompt assessment for potential hemodynamic interventions.

Methods

We used an ensemble of decision trees to obtain a real-time risk score that predicts the initiation of hemodynamic interventions an hour into the future. We developed the model using the eICU Research Institute (eRI) database, based on adult ICU admissions from 2012 to 2016. A total of 208,375 ICU stays met the inclusion criteria, with 32,896 patients (prevalence = 18%) experiencing at least one instability event where they received one of the interventions during their stay. Predictors included vital signs, laboratory measurements, and ventilation settings.

Results

HSI showed significantly better performance compared to single parameters like systolic blood pressure and shock index (heart rate/systolic blood pressure) and showed good generalization across patient subgroups. HSI AUC was 0.82 and predicted 52% of all hemodynamic interventions with a lead time of 1-h with a specificity of 92%. In addition to predicting future hemodynamic interventions, our model provides confidence intervals and a ranked list of clinical features that contribute to each prediction. Importantly, HSI can use a sparse set of physiologic variables and abstains from making a prediction when the confidence is below an acceptable threshold.

Conclusions

The HSI algorithm provides a single score that summarizes hemodynamic status in real time using multiple physiologic parameters in patient monitors and electronic medical records (EMR). Importantly, HSI is designed for real-world deployment, demonstrating generalizability, strong performance under different data availability conditions, and providing model explanation in the form of feature importance and prediction confidence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03808-x.

Combining fluids and vasopressors: A magic potion?

Early detection and prompt reversal of sepsis-induced tissue hypoperfusion are key elements while treating patients with septic shock. Fluid administration is widely accepted as the first-line therapy followed by vasopressor use in persistently hypotensive patients or in those with insufficient arterial pressure to ensure adequate tissue perfusion. Recent evidence suggests a beneficial effect of combining fluids with vasopressors in the early phase of sepsis. Compared with fluids alone, combining fluids and vasopressors increases mean systemic pressure and venous return and corrects hypotension better. This approach also limits fluid overload, which is an independent factor of poor outcomes in sepsis. It produces less hemodilution than fluids alone. As a consequence of these effects, combined treatment may improve outcomes in septic shock patients.

Peripherally Infused Norepinephrine to Avoid Central Venous Catheter Placement in a Medical Intensive Care Unit: A Pilot Study

BACKGROUND

Reducing central venous catheter (CVC) utilization can reduce complications in the intensive care unit (ICU). While norepinephrine (NE) is traditionally administered via a CVC, lower concentrations may be safely administered via peripheral intravenous (PIV) lines.

OBJECTIVE

We aimed to describe the implementation of a pilot protocol utilizing PIVs to administer a low-dose and lower-concentration NE, review the number of CVCs avoided, and evaluate any adverse events.

METHODS

In a quaternary medical intensive care unit (MICU), from March 1, 2019, to February 29, 2020, we reviewed charts for CVC placement and adverse events from the pNE infusion. We also measured unit-level CVC utilization in all MICU patients and assessed the change in utilization associated with the peripheral norepinephrine (pNE) protocol.

RESULTS

Over a 1-year period, 87 patients received a pNE infusion. Overall, 44 patients (51%) never required CVC placement during their MICU stay. Three patients (3%) experienced adverse events, none of which were documented as serious and or required antidote for treatment. Implementation of the protocol was associated with a decrease in the number of patients at the unit level who received CVCs, even if they did not receive pNE.

CONCLUSION AND RELEVANCE

In this small pilot study, we pragmatically demonstrated that pNE is safe and may reduce the need for CVC placement. This information can be used to aid in pNE protocol development and implementation at other institutions, but further research should be done to confirm the safety of routine use of pNE in clinical practice.

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.

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.

Management of sepsis and septic shock in the emergency department

Early management of sepsis and septic shock is crucial for patients' prognosis. As the Emergency Department (ED) is the place where the first medical contact for septic patients is likely to occur, emergency physicians play an essential role in the early phases of patient management, which consists of accurate initial diagnosis, resuscitation, and early antibiotic treatment. Since the issuing of the Surviving Sepsis Campaign guidelines in 2016, several studies have been published on different aspects of sepsis management, adding a substantial amount of new information on the pathophysiology and treatment of sepsis and septic shock. In light of this emerging evidence, the present narrative review provides a comprehensive account of the recent advances in septic patient management in the ED.

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.

Timing of norepinephrine initiation in patients with septic shock: a systematic review and meta-analysis

Background

The effect of the timing of norepinephrine initiation on clinical outcomes in patients with septic shock is uncertain. A systematic review and meta-analysis was performed to evaluate the impact of early and late start of norepinephrine support on clinical outcomes in patients with septic shock.

Methods

We searched the PubMed, Cochrane, and Embase databases for randomized controlled trials (RCTs) and cohort studies from inception to the 1st of March 2020. We included studies involving adult patients (> 18 years) with septic shock. All authors reported our primary outcome of short-term mortality and clearly comparing early versus late norepinephrine initiation with clinically relevant secondary outcomes (ICU length of stay, time to achieved target mean arterial pressure (≥ 65 mmHg), and volume of intravenous fluids within 6 h). Results were expressed as odds ratio (OR) and mean difference (MD) with accompanying 95% confidence interval (CI).

Results

Five studies including 929 patients were included. The primary outcome of this meta-analysis showed that the short-term mortality of the early group was lower than that of the late group (odds ratio [OR] = 0.45; 95% CI, 0.34 to 0.61; P < 0.00001; χ² = 3.74; I² = 0%). Secondary outcomes demonstrated that the time to achieved target MAP of the early group was shorter than that of the late group (mean difference = − 1.39; 95% CI, − 1.81 to − 0.96; P < 0.00001; χ² = 1.03; I² = 0%). The volume of intravenous fluids within 6 h of the early group was less than that of the late group (mean difference = − 0.50; 95% CI, − 0.68 to − 0.32; P < 0.00001; χ² = 33.76; I² = 94%). There was no statistically significant difference in the ICU length of stay between the two groups (mean difference = − 0.11; 95% CI, − 1.27 to 1.05; P = 0.86; χ² = 0.85; I² = 0%).

Conclusions

Early initiation of norepinephrine in patients with septic shock was associated with decreased short-term mortality, shorter time to achieved target MAP, and less volume of intravenous fluids within 6 h. There was no significant difference in ICU length of stay between early and late groups. Further large-scale RCTs are still required to confirm these results.

Timing of norepinephrine initiation in patients with septic shock: a systematic review and meta-analysis

BACKGROUND

The effect of the timing of norepinephrine initiation on clinical outcomes in patients with septic shock is uncertain. A systematic review and meta-analysis was performed to evaluate the impact of early and late start of norepinephrine support on clinical outcomes in patients with septic shock.

METHODS

We searched the PubMed, Cochrane, and Embase databases for randomized controlled trials (RCTs) and cohort studies from inception to the 1st of March 2020. We included studies involving adult patients (> 18 years) with septic shock. All authors reported our primary outcome of short-term mortality and clearly comparing early versus late norepinephrine initiation with clinically relevant secondary outcomes (ICU length of stay, time to achieved target mean arterial pressure (≥ 65 mmHg), and volume of intravenous fluids within 6 h). Results were expressed as odds ratio (OR) and mean difference (MD) with accompanying 95% confidence interval (CI).

RESULTS

Five studies including 929 patients were included. The primary outcome of this meta-analysis showed that the short-term mortality of the early group was lower than that of the late group (odds ratio [OR] = 0.45; 95% CI, 0.34 to 0.61; P < 0.00001; χ² = 3.74; I² = 0%). Secondary outcomes demonstrated that the time to achieved target MAP of the early group was shorter than that of the late group (mean difference = - 1.39; 95% CI, - 1.81 to - 0.96; P < 0.00001; χ² = 1.03; I² = 0%). The volume of intravenous fluids within 6 h of the early group was less than that of the late group (mean difference = - 0.50; 95% CI, - 0.68 to - 0.32; P < 0.00001; χ² = 33.76; I² = 94%). There was no statistically significant difference in the ICU length of stay between the two groups (mean difference = - 0.11; 95% CI, - 1.27 to 1.05; P = 0.86; χ² = 0.85; I² = 0%).

CONCLUSIONS

Early initiation of norepinephrine in patients with septic shock was associated with decreased short-term mortality, shorter time to achieved target MAP, and less volume of intravenous fluids within 6 h. There was no significant difference in ICU length of stay between early and late groups. Further large-scale RCTs are still required to confirm these results.

Vasopressors in septic shock: which, when, and how much?

In addition to fluid resuscitation, the vasopressor therapy is a fundamental treatment of septic shock-induced hypotension as it aims at correcting the vascular tone depression and then at improving organ perfusion pressure. Experts’ recommendations currently position norepinephrine (NE) as the first-line vasopressor in septic shock. Vasopressin and its analogues are only second-line vasopressors as strong recent evidence suggests no benefit of their early administration in spite of promising preliminary data. Early administration of NE may allow achieving the initial mean arterial pressure (MAP) target faster and reducing the risk of fluid overload. The diastolic arterial pressure (DAP) as a marker of vascular tone, helps identifying the patients who need NE urgently. Available data suggest a MAP of 65 mmHg as the initial target but a more individualized approach is often required depending on several factors such as history of chronic hypertension or value of central venous pressure (CVP). In cases of refractory hypotension, increasing NE up to doses ≥1 µg/kg/min could be an option. However, current experts’ guidelines suggest to combine NE with other vasopressors such as vasopressin, with the intent to rising the MAP to target or to decrease the NE dosage.

Time to vasopressor initiation and organ failure progression in early septic shock

OBJECTIVE

Research evaluating the relationship between vasopressor initiation timing and clinical outcomes is limited and conflicting. We investigated the association between time to vasopressors, worsening organ failure, and mortality in patients with septic shock.

METHODS

This was a retrospective study of patients with septic shock (2013-2016) within 24 hours of emergency department (ED) presentation. The primary outcome was worsening organ failure, defined as an increase in Sequential Organ Failure Assessment (SOFA) score ≥2 at 48 hours compared to baseline, or death within 48 hours. The secondary outcome was 28-day mortality. Time to vasopressor initiation was categorized into 6, 4-hour intervals from time of ED triage. Multiple logistic regression was used to identify predictors of worsening organ failure.

RESULTS

We analyzed data from 428 patients with septic shock. There were 152 patients with the composite primary outcome (SOFA increase ≥2 or death at 48 hours). Of these, 77 patients died in the first 48 hours and 75 patients had a SOFA increase ≥2. Compared to the patients who received vasopressors in the first 4 hours, those with the longest time to vasopressors (20-24 hours) had increased odds of developing worsening organ failure (odds ratios [OR] = 4.34, 95% confidence intervals [CI] = 1.47-12.79, P = 0.008). For all others, the association between vasopressor timing and worsening organ failure was non-significant. There was no association between time to vasopressor initiation and 28-day mortality.

CONCLUSIONS

Increased time to vasopressor initiation is an independent predictor of worsening organ failure for patients with vasopressor initiation delays >20 hours.