Optimal target in septic shock resuscitation

Optimizing Mean Arterial Pressure Targets for Septic Shock Patients With Chronic Hypertension: A Narrative Review

BACKGROUND AND AIMS

Septic shock is a serious infection-related condition that has a big effect on public health. To improve organ perfusion and prognosis in septic shock patients with chronic high blood pressure, optimal mean arterial pressure (MAP) targets are needed. This narrative review aims to summarize existing knowledge and factors to determine the most effective MAP targets in septic shock patients with chronic hypertension.

METHODS

A careful review of relevant literature was conducted to understand the factors that affect MAP targets in septic shock patients with chronic hypertension. Long-term hypertension patients require personalized MAP targets based on age, health conditions, and septic shock severity.

RESULTS

five studies were identified in this narrative review. Guidelines suggest 65-75 mmHg for most cases, but higher targets may be beneficial for proper organ perfusion. Continuous hemodynamic monitoring allows dynamic adjustment of MAP targets.

CONCLUSION

It is crucial to implement personalized MAP management strategies to achieve optimal outcomes for patients with chronic hypertension who are experiencing septic shock. However, there is a lack of consensus on optimal MAP targets among patients with chronic hypertension, which may require higher MAP targets to maintain adequate tissue perfusion. An approach that considers each patient's unique characteristics and includes ongoing assessment is critical for achieving the best MAP targets and improving patient prognosis.

Norepinephrine titration in patients with sepsis-induced encephalopathy: cerebral pulsatility index compared to mean arterial pressure guided protocol: randomized controlled trial

BACKGROUND

Although surviving sepsis campaign (SSC) guidelines are the standard for sepsis and septic shock management, outcomes are still unfavourable. Given that perfusion pressure in sepsis is heterogeneous among patients and within the same patient; we evaluated the impact of individualized hemodynamic management via the transcranial Doppler (TCD) pulsatility index (PI) on mortality and outcomes among sepsis-induced encephalopathy (SIE) patients.

METHODS

In this prospective, single-center randomized controlled study, 112 patients with SIE were randomly assigned. Mean arterial pressure (MAP) and norepinephrine (NE) titration were guided via the TCD pulsatility index to achieve a pulsatility index < 1.3 in Group I, whereas the SSC guidelines were used in Group II to achieve a MAP ≥ 65 mmHg. The primary outcome was intensive care unit (ICU) mortality and the secondary outcomes were; MAP that was measured invasively and values were recorded; daily in the morning, at the end of NE infusion and the end of ICU stay, duration of ICU stay, cerebral perfusion pressure (CPP), sequential organ failure assessment (SOFA) score, norepinephrine titration and Glasgow coma scale (GCS) score at discharge.

RESULTS

ICU mortality percentage wasn`t significantly different between the two groups (p value 0.174). There was a significant increase in the MAP at the end of norepinephrine infusion (mean value of 69.54 ± 10.42 and p value 0.002) and in the GCS score at ICU discharge (Median value of 15 and p value 0.014) in the TCD group, and episodes of cerebral hypoperfusion with CPP < 60 mmHg, were significantly lower in the TCD group (median value of 2 and p value 0.018). Heart rate values, number of episodes of tachycardia or bradycardia, Total norepinephrine dosing, duration of norepinephrine infusion, SOFA score, serum lactate levels, and ICU stay duration weren`t significantly different between the two groups.

CONCLUSIONS

Individualizing hemodynamic management via the TCD pulsatility index in SIE patients was not associated with significant mortality reduction. However, it reduces episodes of cerebral hypoperfusion and improves GCS outcome but doesn't significantly affect heart rate values, SOFA score, serum lactate level, length of ICU stay, total NE dosing, and duration of NE infusion.

TRIAL REGISTRATION

The clinical trial was registered on clinucaltrials.gov under the identifier NCT05842616 https://clinicaltrials.gov/study/NCT05842616?cond=NCT05842616&rank=1 on 6-May-2023 before the enrolment of the first patient.

PiCCO or Cardiac Ultrasound? Which Is Better for Hemodynamic Monitoring in ICU?

Advanced hemodynamic monitoring is fundamental in the management of the critically ill. Blood pressure and cardiac function are key markers of cardiovascular system function;, thus, having accurate measurements of these parameters in critically ill patients is essential. Currently, there are various methods available to choose from, as well as a greater understanding of the methods and criteria to be able to compare devices and select the best option for our patients' needs. Cardiac ultrasound and transpulmonary thermodilution help tailor the therapy for a patient's individual needs by putting the results of a thorough hemodynamic assessment into context. Both these hemodynamic monitoring techniques have their advantages, drawbacks and limitations. Cardiac ultrasound is a safe, non-invasive, less expensive, efficient bedside tool for diagnosing, monitoring and guiding critically ill patients' therapy management. It is recommended in the consensus guidelines as the first-choice method, especially when it comes to identifying different types of shock or the various factors involved. Pulse index contour continuous cardiac output (PiCCO) is a minimally invasive hemodynamic monitoring technique, integrating various static and hemodynamic parameters through a combination of trans-cardiopulmonary thermodilution and pulse contour analysis. The PiCCO method provides guidance to fluid and vasoactive therapy in critically ill patients and is also used for intraoperative and postoperative fluid management and monitoring in cardiac surgery. While invasive methods such as PiCCO are recommended for hemodynamic monitoring and can provide accurate information, they are not always necessary and are contraindicated in some cases.

Perspectives for capillary refill time in clinical practice for sepsis

BACKGROUND

Capillary refill time (CRT) is defined as the time taken for color to return to an external capillary bed after pressure is applied to cause blanching. Recent studies demonstrated the benefits of CRT in guiding fluid therapy for sepsis. However, lack of consistency among physicians in how to perform and interpret CRT has led to a low interobserver agreement for this assessment tool, which prevents its availability in sepsis clinical settings.

OBJECTIVE

To give physicians a concise overview of CRT and explore recent evidence on its reliability and value in the management of sepsis.

RESEARCH DESIGN

A narrative review.

RESULTS

This narrative review summarizes the factors affecting CRT values, for example, age, sex, temperature, light, observation techniques, work experience, training level and differences in CRT measurement methods. The methods of reducing the variability of CRT are synthesized. Based on studies with highly reproducible CRT measurements and an excellent inter-rater concordance, we recommend the standardized CRT assessment method. The threshold of normal CRT values is discussed. The application of CRT in different phases of sepsis management is summarized.

CONCLUSIONS

Recent data confirm the value of CRT in critically ill patients. CRT should be detected by trained physicians using standardized methods and reducing the effect of ambient-related factors. Its association with severe infection, microcirculation, tissue perfusion response, organ dysfunction and adverse outcomes makes this approach a very attractive tool in sepsis. Further studies should confirm its value in the management of sepsis.

IMPLICATIONS FOR CLINICAL PRACTICE

As a simple assessment, CRT deserves more attention even though it has not been widely applied at the bedside. CRT could provide nursing staff with patient's microcirculatory status, which may help to develop individualized nursing plans and improve the patient's care quality and treatment outcomes.

Impact of different intravenous bolus rates on fluid and electrolyte balance and mortality in critically ill patients

The effect of intravenous bolus rates on patient outcomes is a complex and crucial aspect of critical care. Fluid challenges are commonly used in critically ill patients to manage their hemodynamic status, but there is limited information available on the specifics of when, how much, and at what rate fluids should be administered during these challenges. The aim of this review is to thoroughly examine the relationship between intravenous bolus rates, fluid-electrolyte balance, and mortality and to analyze key research findings and methodologies to understand these complex dynamics better. Fluid challenges are commonly employed in managing hemodynamic status in this population, yet there is limited information on the optimal timing, volume, and rate of fluid administration. Utilizing a narrative review approach, the analysis identified nine relevant studies that investigate these variables. The findings underscore the importance of a precise and individualized approach in clinical settings, highlighting the need to tailor intravenous bolus rates to each patient's specific needs to maximize outcomes. This review provides valuable insights that can inform and optimize clinical practices in critical care, emphasizing the necessity of meticulous and exact strategies in fluid administration.

Hemodynamic goals in sepsis and septic shock resuscitation: An umbrella review of systematic reviews and meta-analyses with trial sequential analysis

OBJECTIVE

The objective of this study was to verify whether any parameter among those used as the target for haemodynamic optimisation (e.g., mean arterial pressure, central venous oxygen saturation, systolic or diastolic dysfunction, CO2 gap, lactates, right ventricular dysfunction, and PvaCO2/CavO2 ratio) is correlated with mortality in an undifferentiated population with sepsis or septic shock.

METHODS

An umbrella review, searching MEDLINE, the Cochrane Database of Systematic Reviews, Health Technology Assessment Database, and the JBI Database of Systematic Reviews and Implementation Reports, was performed. We included systematic reviews and meta-analyses enrolling a population of unselected patients with sepsis or septic shock. The main outcome was mortality. Two authors conducted data extraction and risk-of-bias assessments independently. We used a random-effects model to pool binary and continuous data and summarised estimates of effect using equivalent odds ratios (eORs). We used the ROBIS tool to assess risk of bias and the assessment of multiple systematic reviews 2 score to assess global quality.

DATA SYNTHESIS

17 systematic reviews and meta-analyses (15 828 patients) were included in the quantitative analysis. Diastolic dysfunction (eOR: 1.42; 95% confidence interval [CI]: 1.14-1.76), PvaCO2/CavO2 ratio (eOR: 2.15; 95% CI: 1.37-3.37), and CO2 gap (eOR: 1.86; 95% CI: 1.07-3.25) showed a significant correlation with mortality. Lactates were the parameter with highest inconsistency (I2 = 92%). Central venous oxygen saturation and right ventricle dysfunction showed significant statistical excess test of significance (p-value = 0.009 and 0.005, respectively). None of the considered parameters showed statistically significant publication bias.

CONCLUSIONS

According to this umbrella review, diastolic dysfunction is the haemodynamic variable that is most closely linked to the prognosis of septic patients. The PvaCO2/CavO2 ratio and the CO2gap are significantly related to the mortality of septic patients, but the poor quality of evidence or the low number of cases, studied so far, limit their clinical applicability.

CLINICAL TRIAL REGISTRATION

PROSPERO: International prospective register of systematic reviews, 2023, CRD42023432813 (Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023432813).

MAN VERSUS MACHINE: PROVIDER DIRECTED VERSUS PRECISION AUTOMATED CRITICAL CARE MANAGEMENT IN A PORCINE MODEL OF DISTRIBUTIVE SHOCK

ABSTRACT

Background: Critical care management of shock is a labor-intensive process. Precision Automated Critical Care Management (PACC-MAN) is an automated closed-loop system incorporating physiologic and hemodynamic inputs to deliver interventions while avoiding excessive fluid or vasopressor administration. To understand PACC-MAN efficacy, we compared PACC-MAN to provider-directed management (PDM). We hypothesized that PACC-MAN would achieve equivalent resuscitation outcomes to PDM while maintaining normotension with lower fluid and vasopressor requirements. Methods : Twelve swine underwent 30% controlled hemorrhage over 30 min, followed by 45 min of aortic occlusion to generate a vasoplegic shock state, transfusion to euvolemia, and randomization to PACC-MAN or PDM for 4.25 h. Primary outcomes were total crystalloid volume, vasopressor administration, total time spent at hypotension (mean arterial blood pressure <60 mm Hg), and total number of interventions. Results : Weight-based fluid volumes were similar between PACC-MAN and PDM; median and IQR are reported (73.1 mL/kg [59.0-78.7] vs. 87.1 mL/kg [79.4-91.8], P = 0.07). There was no statistical difference in cumulative norepinephrine (PACC-MAN: 33.4 μg/kg [27.1-44.6] vs. PDM: 7.5 [3.3-24.2] μg/kg, P = 0.09). The median percentage of time spent at hypotension was equivalent (PACC-MAN: 6.2% [3.6-7.4] and PDM: 3.1% [1.3-6.6], P = 0.23). Urine outputs were similar between PACC-MAN and PDM (14.0 mL/kg vs. 21.5 mL/kg, P = 0.13). Conclusion : Automated resuscitation achieves equivalent resuscitation outcomes to direct human intervention in this shock model. This study provides the first translational experience with the PACC-MAN system versus PDM.

Research progress on microcirculatory disorders in septic shock: A narrative review

Hemodynamic coherence plays a critical role in the outcomes of septic shock. Due to the potential negative consequences of microcirculatory disorders on organ failure and clinical outcomes, the maintenance of a balance between the macrocirculation and microcirculation is a topic of significant research focus. Although physical methods and specialized imaging techniques are used in clinical practice to assess microcirculation, the use of monitoring devices is not widespread. The integration of microcirculation research tools into clinical practice poses a significant challenge for the future. Consequently, this review aims to evaluate the impact of septic shock on the microcirculation, the methods used to monitor the microcirculation and highlight the importance of microcirculation in the treatment of critically ill patients. In addition, it proposes an evaluation framework that integrates microcirculation monitoring with macrocirculatory parameters. The optimal approach should encompass dynamic, multiparametric, individualized, and continuous monitoring of both the macrocirculation and microcirculation, particularly in cases of hemodynamic separation.

Coexistence of a fluid responsive state and venous congestion signals in critically ill patients: a multicenter observational proof-of-concept study

BACKGROUND

Current recommendations support guiding fluid resuscitation through the assessment of fluid responsiveness. Recently, the concept of fluid tolerance and the prevention of venous congestion (VC) have emerged as relevant aspects to be considered to avoid potentially deleterious side effects of fluid resuscitation. However, there is paucity of data on the relationship of fluid responsiveness and VC. This study aims to compare the prevalence of venous congestion in fluid responsive and fluid unresponsive critically ill patients after intensive care (ICU) admission.

METHODS

Multicenter, prospective cross-sectional observational study conducted in three medical-surgical ICUs in Chile. Consecutive mechanically ventilated patients that required vasopressors and admitted < 24 h to ICU were included between November 2022 and June 2023. Patients were assessed simultaneously for fluid responsiveness and VC at a single timepoint. Fluid responsiveness status, VC signals such as central venous pressure, estimation of left ventricular filling pressures, lung, and abdominal ultrasound congestion indexes and relevant clinical data were collected.

RESULTS

Ninety patients were included. Median age was 63 [45-71] years old, and median SOFA score was 9 [7-11]. Thirty-eight percent of the patients were fluid responsive (FR+), while 62% were fluid unresponsive (FR-). The most prevalent diagnosis was sepsis (41%) followed by respiratory failure (22%). The prevalence of at least one VC signal was not significantly different between FR+ and FR- groups (53% vs. 57%, p = 0.69), as well as the proportion of patients with 2 or 3 VC signals (15% vs. 21%, p = 0.4). We found no association between fluid balance, CRT status, or diagnostic group and the presence of VC signals.

CONCLUSIONS

Venous congestion signals were prevalent in both fluid responsive and unresponsive critically ill patients. The presence of venous congestion was not associated with fluid balance or diagnostic group. Further studies should assess the clinical relevance of these results and their potential impact on resuscitation and monitoring practices.

Effect on capillary refill time of volume expansion and increase of the norepinephrine dose in patients with septic shock

BACKGROUND

Capillary refill time (CRT) has been suggested as a variable to follow during the course of septic shock. We systematically investigated the effects on CRT of volume expansion and norepinephrine.

METHODS

In 69 septic shock patients, we recorded mean arterial pressure (MAP), cardiac index (CI), and 5 consecutive CRT measurements (video method, standardized pressure applied on the fingertip) before and after a 500-mL saline infusion in 33 patients and before and after an increase of the norepinephrine dose in 36 different patients. Fluid responders were defined by an increase in CI ≥ 15%, and norepinephrine responders by an increase in MAP ≥ 15%.

RESULTS

The least significant change of CRT was 23%, so that changes in CRT were considered significant if larger than 23%. With volume expansion, CRT remained unchanged on average in patients with baseline CRT < 3 s (n = 7) and in all but one patient with baseline CRT ≥ 3 s in whom fluid increased CI < 15% (n = 13 "fluid non-responders"). In fluid responders with baseline CRT ≥ 3 s (n = 13), CRT decreased in 8 patients and remained unchanged in the others, exhibiting a dissociation between CI and CRT responses. The proportion of patients included > 24 h after starting norepinephrine was higher in patients with such a dissociation than in the other ones (60% vs. 0%, respectively). Norepinephrine did not change CRT significantly (except in one patient) if baseline CRT was ≥ 3 s and the increase in MAP < 15% (n = 6). In norepinephrine responders with prolonged baseline CRT (n = 11), it increased in 4 patients and remained unchanged in the other ones, which exhibited a dissociation between MAP and CRT responses.

CONCLUSIONS

In septic shock patients with prolonged CRT, CRT very rarely improves with treatment when volume expansion increases cardiac output < 15% and increasing norepinephrine increases MAP < 15%. When the effects of fluid infusion on cardiac output and of norepinephrine on MAP are significant, the response of CRT is variable, as it decreases in some patients and remains stable in others which exhibit a dissociation between changes in macrohemodynamic variables and in CRT. In this regard, CRT behaves as a marker of microcirculation.

TRIAL REGISTRATION

ClinicalTrial.gov (NCT04870892). Registered January15, 2021. Ethics committee approval CE SRLF 21-25.

Bedside Hyperspectral Imaging and Organ Dysfunction Severity in Critically Ill COVID-19 Patients-A Prospective, Monocentric Observational Study

Hyperspectral imaging (HSI) is a non-invasive technology that provides information on biochemical tissue properties, including skin oxygenation and perfusion quality. Microcirculatory alterations are associated with organ dysfunction in septic COVID-19 patients. This prospective observational study investigated associations between skin HSI and organ dysfunction severity in critically ill COVID-19 patients. During the first seven days in the ICU, palmar HSI measurements were carried out with the TIVITA® tissue system. We report data from 52 critically ill COVID-19 patients, of whom 40 required extracorporeal membrane oxygenation (ECMO). HSI parameters for superficial tissue oxygenation (StO2) and oxygenation and perfusion quality (NPI) were persistently decreased. Hemoglobin tissue content (THI) increased, and tissue water content (TWI) was persistently elevated. Regression analysis showed strong indications for an association of NPI and weaker indications for associations of StO2, THI, and TWI with sequential organ failure assessment (SOFA) scoring. StO2 and NPI demonstrated negative associations with vasopressor support and lactate levels as well as positive associations with arterial oxygen saturation. These results suggest that skin HSI provides clinically relevant information, opening new perspectives for microcirculatory monitoring in critical care.

Identification of Potential Biomarkers of Septic Shock Based on Pathway and Transcriptome Analyses of Immune-Related Genes

Immunoregulation is crucial to septic shock (SS) but has not been clearly explained. Our aim was to explore potential biomarkers for SS by pathway and transcriptional analyses of immune-related genes to improve early detection. GSE57065 and GSE95233 microarray data were used to screen differentially expressed genes (DEGs) in SS. Gene Ontology and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analyses of DEGs were performed, and correlations between immune cell and pathway enrichment scores were analyzed. The predictive value of candidate genes was evaluated by receiver operating characteristic (ROC) curves. GSE66099, GSE4607, and GSE13904 datasets were used for external validation. Blood samples from six patients and six controls were collected for validation by qRT-PCR and western blotting. In total, 550 DEGs in SS were identified; these genes were involved in the immune response, inflammation, and infection. Immune-related pathways and levels of infiltration of CD4 + TCM, CD8 + T cells, and preadipocytes differed between SS cases and controls. Seventeen genes were identified as potential biomarkers of SS (areas under ROC curves >0.9). The downregulation of CD8A, CD247, CD3G, LCK, and HLA-DRA in SS was experimentally confirmed. We identified several immune-related biomarkers in SS that may improve early identification of disease risk.

Incidence Rate and Factors Associated with Delirium and Subsyndromal Delirium in Patients with COVID-19 in an Intensive Care Unit

BACKGROUND

Delirium subsyndrome (SSD) and delirium (DL) are known complications in the intensive care unit (ICU) and are associated with worse clinical outcomes. The aim of this study was to screen for SSD and DL in individuals with COVID-19 admitted to the ICU and to study the associated factors and clinical outcomes.

METHOD

An observational, longitudinal study was conducted in the reference ICU for COVID-19. All admitted individuals with COVID-19 were screened for SSD and DL during their ICU stay using the Intensive Care Delirium Screening Checklist (ICDSC). Individuals with SSD and/or DL were compared to those without SSD and/or DL.

RESULTS

Ninety-three patients were evaluated, of which 46.7% had SSD and/or DL. The incidence rate was 4.17 cases/100 person-days. Individuals with SSD and/or DL had higher severity of illness on admission to the ICU, as measured by the APACHE II score (median 16 versus 8 points, p < 0.001). SSD and/or DL were associated with longer ICU and hospital stays (median 19 versus 6 days, p < 0.001 and median 22 versus 7 days, p < 0.001, respectively).

CONCLUSION

Individuals with SSD and/or DL had greater disease severity and longer ICU and hospital stays when compared to those without SSD and/or DL. This reinforces the importance of screening for consciousness disorders in the ICU.

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.

Pathophysiology of fluid administration in critically ill patients

Fluid administration is a cornerstone of treatment of critically ill patients. The aim of this review is to reappraise the pathophysiology of fluid therapy, considering the mechanisms related to the interplay of flow and pressure variables, the systemic response to the shock syndrome, the effects of different types of fluids administered and the concept of preload dependency responsiveness. In this context, the relationship between preload, stroke volume (SV) and fluid administration is that the volume infused has to be large enough to increase the driving pressure for venous return, and that the resulting increase in end-diastolic volume produces an increase in SV only if both ventricles are operating on the steep part of the curve. As a consequence, fluids should be given as drugs and, accordingly, the dose and the rate of administration impact on the final outcome. Titrating fluid therapy in terms of overall volume infused but also considering the type of fluid used is a key component of fluid resuscitation. A single, reliable, and feasible physiological or biochemical parameter to define the balance between the changes in SV and oxygen delivery (i.e., coupling "macro" and "micro" circulation) is still not available, making the diagnosis of acute circulatory dysfunction primarily clinical.

The emerging concept of fluid tolerance: A position paper

Fluid resuscitation is a core component of emergency and critical care medicine. While the focus of clinicians has largely been on detecting patients who would respond to fluid therapy, relatively little work has been done on assessing patients' tolerance to this therapy. In this article we seek to review the concept of fluid tolerance, propose a working definition, and introduce relevant clinical signals by which physicians can assess fluid tolerance, hopefully becoming a starting point for further research.

Effective hemodynamic monitoring

Hemodynamic monitoring is the centerpiece of patient monitoring in acute care settings. Its effectiveness in terms of improved patient outcomes is difficult to quantify. This review focused on effectiveness of monitoring-linked resuscitation strategies from: (1) process-specific monitoring that allows for non-specific prevention of new onset cardiovascular insufficiency (CVI) in perioperative care. Such goal-directed therapy is associated with decreased perioperative complications and length of stay in high-risk surgery patients. (2) Patient-specific personalized resuscitation approaches for CVI. These approaches including dynamic measures to define volume responsiveness and vasomotor tone, limiting less fluid administration and vasopressor duration, reduced length of care. (3) Hemodynamic monitoring to predict future CVI using machine learning approaches. These approaches presently focus on predicting hypotension. Future clinical trials assessing hemodynamic monitoring need to focus on process-specific monitoring based on modifying therapeutic interventions known to improve patient-centered outcomes.

Capillary refill time in sepsis: A useful and easily accessible tool for evaluating perfusion in children

The international sepsis guidelines emphasize the importance of early identification along with the combined administration of fluids, antibiotics and vasopressors as essential steps in the treatment of septic shock in childhood. However, despite these recommendations, septic shock mortality continues to be very high, especially in countries with limited resources. Cardiovascular involvement is common and, in most cases, determines the outcomes. Early recognition of hemodynamic dysfunction, both in the macro and microcirculation, can help improve outcomes. Capillary refill time (CRT) is a useful, available and easily accessible tool at all levels of care. It is a clinical sign of capillary vasoconstriction due to an excessive sympathetic response which seeks to improve blood redistribution from the micro- to the macrocirculation. An important reason for functionally evaluating the microcirculation is that, in septic shock, the correction of macrocirculation variables is assumed to result in improved tissue perfusion. This has been termed "hemodynamic coherence." However, this coherence often does not occur in advanced stages of the disease. Capillary refill time is useful in guiding fluid resuscitation and identifying more seriously affected sepsis patients. Several factors can affect its measurement, which should preferably be standardized and performed on the upper extremities. In this review, we seek to clarify a few common questions regarding CRT and guide its correct use in patients with sepsis.

Norepinephrine Dosage Is Associated With Lactate Clearance After Resuscitation in Patients With Septic Shock

Background: Some septic shock patients have persistent hyperlactacidemia despite a normal systemic hemodynamics after resuscitation. Central venous oxygen saturation (ScvO₂), mean arterial pressure (MAP), and central venous pressure (CVP) cannot be target in subsequent hemodynamic treatments. Vasoplegia is considered to be one of the main causes of oxygen metabolism abnormalities in septic shock patients, and norepinephrine (NE) is the first-line vasopressor in septic shock treatment; its dosage represents the severity of vasoplegia. This study was performed to determine whether vasoplegia, as assessed by NE dosage, can indicate patients' lactate clearance after the completion of resuscitation.

Methods: A retrospective study was performed, and 106 patients with septic shock in an intensive care unit were analyzed. Laboratory values and hemodynamic variables were obtained upon completion of resuscitation (H 0) and 6 h after (H 6). Lactate clearance was defined as the percent decrease in lactate from H 0 to H 6. Student's t-test, Mann-Whitney U-test, Chi-square or Fisher's exact tests, logistic regression analysis, and receiver operating characteristic (ROC) curve analysis were performed for statistical analysis.

Results: Patients with a mean age of 63.7 ± 13.8 years, baseline APACHE II score of 21.0 ± 5.1, and SOFA score of 12.7 ± 2.7 were enrolled. The study found that after 6-h of resuscitation, lactate clearance (LC) was <10% in 33 patients (31.1%). Patients with 6-h LC <10% compared with 6-h LC ≥ 10% had a higher NE dose (μg·kg⁻¹·min⁻¹) (0.55 [0.36–0.84] vs. 0.25 [0.18–0.41], p < 0.001). Multivariate logistic regression analysis of statistically significant univariate variables showed that NE dose had a significant inverse relationship with 6-h LC < 10%. The cutoff for NE was ≥ 0.32 μg·kg⁻¹·min⁻¹ for predicting 6-h lactate clearance after resuscitation, with a sensitivity of 75.76% and a specificity of 70.00%. Septic shock patients with an NE dose ≥ 0.32 μg·kg⁻¹·min⁻¹, relative to patients with an NE dose < 0.32 μg·kg⁻¹·min⁻¹, had a greater 30-day mortality rate (69.8% vs. 26.4% p < 0.001).

Conclusion: Some patients with septic shock had persistent oxygen metabolism disorders after hemodynamic resuscitation. NE dose may indicate vasoplegia and oxygen metabolism disorder. After resuscitation, septic shock patients with high-dose NE have lower lactate clearance and a greater 30-day mortality rate than those with low-dose NE.

Clinical characteristics and in-hospital mortality of patients with COVID-19 in Chile: A prospective cohort study

AIMS OF THIS STUDY

To describe the Latin American population affected by COVID-19, and to determine relevant risk factors for in-hospital mortality.

METHODS

We prospectively registered relevant clinical, laboratory, and radiological data of adult patients with COVID-19, admitted within the first 100 days of the pandemic from a single teaching hospital in Santiago, Chile. The primary outcome was in-hospital mortality. Secondary outcomes included the need for respiratory support and pharmacological treatment, among others. We combined the chronic disease burden and the severity of illness at admission with predefined clinically relevant risk factors. Cox regression models were used to identify risk factors for in-hospital mortality.

RESULTS

We enrolled 395 adult patients, their median age was 61 years; 62.8% of patients were male and 40.1% had a Modified Charlson Comorbidity Index (MCCI) ≥5. Their median Sequential Organ Failure Assessment (SOFA) score was 3; 34.9% used a high-flow nasal cannula and 17.5% required invasive mechanical ventilation. The in-hospital mortality rate was 14.7%. In the multivariate analysis, were significant risk factors for in-hospital mortality: MCCI ≥5 (HR 4.39, P < .001), PaO₂ /FiO₂ ratio ≤200 (HR 1.92, P = .037), and advanced chronic respiratory disease (HR 3.24, P = .001); pre-specified combinations of these risk factors in four categories was associated with the outcome in a graded manner.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The relationship between multiple prognostic factors has been scarcely reported in Latin American patients with COVID-19. By combining different clinically relevant risk factors, we can identify COVID-19 patients with high-, medium- and low-risk of in-hospital mortality.

Hemodynamic Monitoring in Sepsis-A Conceptual Framework of Macro- and Microcirculatory Alterations

Circulatory failure in sepsis is common and places a considerable burden on healthcare systems. It is associated with an increased likelihood of mortality, and timely recognition is a prerequisite to ensure optimum results. While there is consensus that aggressive source control, adequate antimicrobial therapy and hemodynamic management constitute crucial determinants of outcome, discussion remains about the best way to achieve each of these core principles. Sound cardiovascular support rests on tailored fluid resuscitation and vasopressor therapy. To this end, an overarching framework to improve cardiovascular dynamics has been a recurring theme in modern critical care. The object of this review is to examine the nature of one such framework that acknowledges the growing importance of adaptive hemodynamic support combining macro- and microhemodynamic variables to produce adequate tissue perfusion.

Cutting-Edge Technology for Rapid Bedside Assessment of Capillary Refill Time for Early Diagnosis and Resuscitation of Sepsis

Sepsis currently affects over 30 million people globally with a mortality rate of ~30%. Prompt Emergency Department diagnosis and initiation of resuscitation improves outcomes; data has found an 8% increase in mortality for every hour delay in diagnosis. Once sepsis is recognized, the current Surviving Sepsis Guidelines for adult patients mandate the initiation of antibiotics within 3 h of emergency department triage as well as 30 milliliters per kilogram of intravenous fluids. While these are important parameters to follow, many emergency departments fail to meet these goals for a variety of reasons including turnaround on blood tests such as the serum lactate that may be delayed or require expensive laboratory equipment. However, patients routinely have vital signs assessed and measured in triage within 30 min of presentation. This creates a unique opportunity for implementation point for cutting-edge technology to significantly reduce the time to diagnosis of potentially septic patients allowing for earlier initiation of treatment. In addition to the practical and clinical difficulties with early diagnosis of sepsis, recent clinical trials have shown higher morbidity and mortality when septic patients are over-resuscitated. Technology allowing more real time monitoring of a patient's physiologic responses to resuscitation may allow for more individualized care in emergency department and critical care settings. One such measure at the bedside is capillary refill. This has shown favor in the ability to differentiate subsets of patients who may or may not need resuscitation and interpreting blood values more accurately (1, 2). This is a well-recognized measure of distal perfusion that has been correlated to sepsis outcomes. This physical exam finding is performed routinely, however, there is significant variability in the measurement based on who is performing it. Therefore, technology allowing rapid, objective, non-invasive measurement of capillary refill could improve sepsis recognition compared to algorithms that require lab tests included lactate or white blood count. This manuscript will discuss the broad application of capillary refill to resuscitation care and sepsis in particular for adult patients but much can be applied to pediatrics as well. The authors will then introduce a new technology that has been developed through a problem-based innovation approach to allow clinicians rapid assessment of end-organ perfusion at the bedside or emergency department triage and be incorporated into the electronic medical record. Future applications for identifying patient decompensation in the prehospital and home environment will also be discussed. This new technology has 3 significant advantages: [1] the use of reflected light technology for capillary refill assessment to provide deeper tissue penetration with less signal-to-noise ratio than transmitted infrared light, [2] the ability to significantly improve clinical outcomes without large changes to clinical workflow or provider practice, and [3] it can be used by individuals with minimal training and even in low resource settings to increase the utility of this technology. It should be noted that this perspective focuses on the utility of capillary refill for sepsis care, but it could be considered the next standard of care vital sign for assessment of end-organ perfusion. The ultimate goal for this sensor is to integrate it into existing monitors within the healthcare system.