Fluid Response Evaluation in Sepsis Hypotension and Shock: A Randomized Clinical Trial

A service evaluation of measuring fluid responsiveness in acutely unwell hypotensive patients outside of critical care

INTRODUCTION

Early recognition and prompt, appropriate management may reduce mortality in patients with sepsis. The Surviving Sepsis Campaign's guidelines suggest the use of dynamic measurements to guide fluid resuscitation in sepsis; although these methods are rarely employed to monitor cardiac output in response to fluid administration outside intensive care units. This service evaluation investigated the introduction of a nurse led protocolised goal-directed fluid management using a non-invasive cardiac output monitor to the standard assessment of hypotensive ward patients.

METHODS

We introduced the use of a goal-directed fluid management protocol into our critical care outreach teams' standard clinical assessment. Forty-nine sequential patients before and thirty-nine after its introduction were included in the assessment.

RESULTS

Patients in the post-intervention cohort received less fluid in the 6 h following outreach assessment (750mls vs 1200mls). There were no differences in clinical background or rates of renal replacement therapy, but rates of invasive and non-invasive ventilation were reduced (0% vs 31%). Although the groups were similar, the post-intervention patients had lower recorded blood pressures.

CONCLUSION

IV fluid therapy in the patient with hypotension complicating sepsis can be challenging. Excessive IV fluid administration is commonplace and associated with harm, and the use of advanced non-invasive haemodynamic monitoring by trained nurses can provide objective evaluation of individualised response to treatment. Avoiding excessive IV fluid and earlier institution of appropriate vasopressor therapy may improve patient outcomes.

IMPLICATIONS FOR CLINICAL PRACTICE

Adoption of dynamic measures of cardiac output outside of critical care by trained critical care nurses is feasible and may translate into improved patient outcomes. In hospitals with a nurse-led critical care outreach service, consideration should be given to such an approach.

Maternal sepsis: Clinical pearls for diagnosis and management

Sepsis is a leading cause of maternal morbidity and mortality worldwide. Early recognition and treatment improve outcomes. Multiple sepsis diagnostic screening tools are available and may be used in clinical practice; however, early thorough bedside evaluation of the patient is fundamental. Obstetricians should be able to recognize sepsis and promptly initiate potentially life-saving treatments, such as fluid resuscitation, vasopressors, broad-spectrum antibiotics, and early source control. It is recommended that obstetrical care, including delivery timing, not be altered solely due to the diagnosis of sepsis.

Wearable ultrasound devices: An emerging era for biomedicine and clinical translation

In recent years, personalized diagnosis and treatment have gained significant recognition and rapid development in the biomedicine and healthcare. Due to the flexibility, portability and excellent compatibility, wearable ultrasound (WUS) devices have become emerging personalized medical devices with great potential for development. Currently, with the development of the ongoing advancements in materials and structural design of the ultrasound transducers, WUS devices have improved performance and are increasingly applied in the medical field. In this review, we provide an overview of the design and structure of WUS devices, focusing on their application for diagnosis and treatment of various diseases from a clinical application perspective, and then explore the issues that need to be addressed before clinical translation. Finally, we summarize the progress made in the development of WUS devices, and discuss the current challenges and the future direction of their development. In conclusion, WUS devices usher an emerging era for biomedicine with great clinical promise.

CCL14 testing to guide clinical practice in patients with AKI: Results from an international expert panel

PURPOSE

Urinary C-C motif chemokine ligand 14 (CCL14) is a strong predictor of persistent stage 3 acute kidney injury (AKI). Multiple clinical actions are recommended for AKI but how these are applied in individual patients and how the CCL14 test results may impact their application is unknown.

METHODS

We assembled an international panel of 12 experts and conducted a modified Delphi process to evaluate patients at risk for persistent stage 3 AKI (lasting 72 hours or longer). Using a Likert scale, we rated 11 clinical actions based on international guidelines applied to each case before and after CCL14 testing and analyzed the association between the strength and direction of recommendations and CCL14 results.

RESULTS

The strength and direction of clinical recommendations were strongly influenced by CCL14 results (P < 0.001 for the interaction). Nine (82%) recommendations for clinical actions were significantly impacted by CCL14 results (P < 0.001 comparing low to highest CCL14 risk category).

CONCLUSIONS

Most recommendations for care of patients with stage 2-3 by an international panel of experts were strongly modified by CCL14 test results. This work should set the stage for clinical practice protocols and studies to determine the effects of recommended actions informed by CCL14.

Effects of dynamic versus static parameter-guided fluid resuscitation in patients with sepsis: A randomized controlled trial

Background

Fluid resuscitation is an essential component for sepsis treatment. Although several studies demonstrated that dynamic variables were more accurate than static variables for prediction of fluid responsiveness, fluid resuscitation guidance by dynamic variables is not standard for treatment. The objectives were to determine the effects of dynamic inferior vena cava (IVC)-guided versus (vs.) static central venous pressure (CVP)-guided fluid resuscitation in septic patients on mortality; and others, i.e., resuscitation targets, shock duration, fluid and vasopressor amount, invasive respiratory support, length of stay and adverse events.

Methods

A single-blind randomized controlled trial was conducted at Thammasat University Hospital between August 2016 and April 2020. Septic patients were stratified by acute physiologic and chronic health evaluation II (APACHE II) <25 or ≥25 and randomized by blocks of 2 and 4 to fluid resuscitation guidance by dynamic IVC or static CVP.

Results

Of 124 patients enrolled, 62 were randomized to each group, and one of each was excluded from mortality analysis. Baseline characteristics were comparable. The 30-day mortality rates between dynamic IVC vs. static CVP groups were not different (34.4% vs. 45.9%, p=0.196). Relative risk for 30-day mortality of dynamic IVC group was 0.8 (95%CI=0.5-1.2, p=0.201). Different outcomes were median (interquartile range) of shock duration (0.8 (0.4-1.6) vs. 1.5 (1.1-3.1) days, p=0.001) and norepinephrine (NE) dose (6.8 (3.9-17.8) vs. 16.1 (7.6-53.6) milligrams, p=0.008 and 0.1 (0.1-0.3) vs. 0.3 (0.1-0.8) milligram⋅kilogram -1, p=0.017). Others were not different.

Conclusions

Dynamic IVC-guided fluid resuscitation does not affect mortality of septic patients. However, this may reduce shock duration and NE dose, compared with static CVP guidance.

The role of point-of-care ultrasound to monitor response of fluid replacement therapy in pregnancy

Fluid management in obstetrical care is crucial because of the complex physiological conditions of pregnancy, which complicate clinical manifestations and fluid balance management. This expert review examined the use of point-of-care ultrasound to evaluate and monitor the response to fluid therapy in pregnant patients. Pregnancy induces substantial physiological changes, including increased cardiac output and glomerular filtration rate, decreased systemic vascular resistance, and decreased plasma oncotic pressure. Conditions, such as preeclampsia, further complicate fluid management because of decreased intravascular volume and increased capillary permeability. Traditional methods for assessing fluid volume status, such as physical examination and invasive monitoring, are often unreliable or inappropriate. Point-of-care ultrasound provides a noninvasive, rapid, and reliable means to assess fluid responsiveness, which is essential for managing fluid therapy in pregnant patients. This review details the various point-of-care ultrasound modalities used to measure dynamic changes in fluid status, focusing on the evaluation of the inferior vena cava, lung ultrasound, and left ventricular outflow tract. Inferior vena cava ultrasound in spontaneously breathing patients determines diameter variability, predicts fluid responsiveness, and is feasible even late in pregnancy. Lung ultrasound is crucial for detecting early signs of pulmonary edema before clinical symptoms arise and is more accurate than traditional radiography. The left ventricular outflow tract velocity time integral assesses stroke volume response to fluid challenges, providing a quantifiable measure of cardiac function, which is particularly beneficial in critical care settings where rapid and accurate fluid management is essential. This expert review synthesizes current evidence and practice guidelines, suggesting the integration of point-of-care ultrasound as a fundamental aspect of fluid management in obstetrics. It calls for ongoing research to enhance techniques and validate their use in broader clinical settings, aiming to improve outcomes for pregnant patients and their babies by preventing complications associated with both under- and overresuscitation.

Relationship Between Fluid Administration During the First Three Hours of Sepsis Resuscitation and Mortality: A Multicenter Observational Study

Background Timely and effective fluid resuscitation is vital for stabilizing sepsis while avoiding volume overload. We aimed to assess how the administration of a 30 mL/kg bolus fluid affects patients with sepsis within three hours of clinical outcomes. Methods This multicenter observational study included adult patients diagnosed with sepsis in 17 intensive care units at tertiary hospitals in Japan between July 2019 and August 2020. The clinical outcomes of patients with sepsis who received ≥30 mL/kg bolus fluid within three hours (30 × 3 group) were compared with those who received <30 mL/kg fluid (non-30 × 3 group). Results Of 172 eligible patients, 74 (43.0%) belonged to the 30 × 3 group, and 98 (57.0%) belonged to the non-30 × 3 group. The median Sequential Organ Failure Assessment score was 9 (interquartile range (Q1-Q3): 7-11) in the 30 × 3 group and 7 (Q1-Q3: 4-9) in the non-30 × 3 group (P < 0.01). The 28-day mortality rate was 29.7% in the 30 × 3 group and 12.2% in the non-30 × 3 group (P < 0.01). However, the adjusted odds ratio by the inverse probability of treatment weighting analysis with propensity score for the 28-day mortality rate of the 30 × 3 group compared with that in the non-30 × 3 group was 2.17 (95% confidence interval: 0.85-5.54). Among the propensity score-matched patients, the 28-day mortality rate was 30% in the 30 × 3 (n = 70) and non-30 × 3 (n = 95) groups, respectively (P = 0.72). Conclusions Patients with sepsis who received the 30 mL/kg bolus fluid within three hours experienced more severe clinical outcomes. However, it was not associated with the increased odds of the 28-day mortality.

Hemodynamic Support in Sepsis

This review discusses recent evidence in managing sepsis-induced hemodynamic alterations and how it can be integrated with previous knowledge for actionable interventions in adult patients.

Revolution in sepsis: a symptoms-based to a systems-based approach?

Severe infection and sepsis are medical emergencies. High morbidity and mortality are linked to CNS dysfunction, excessive inflammation, immune compromise, coagulopathy and multiple organ dysfunction. Males appear to have a higher risk of mortality than females. Currently, there are few or no effective drug therapies to protect the brain, maintain the blood brain barrier, resolve excessive inflammation and reduce secondary injury in other vital organs. We propose a major reason for lack of progress is a consequence of the treat-as-you-go, single-nodal target approach, rather than a more integrated, systems-based approach. A new revolution is required to better understand how the body responds to an infection, identify new markers to detect its progression and discover new system-acting drugs to treat it. In this review, we present a brief history of sepsis followed by its pathophysiology from a systems' perspective and future opportunities. We argue that targeting the body's early immune-driven CNS-response may improve patient outcomes. If the barrage of PAMPs and DAMPs can be reduced early, we propose the multiple CNS-organ circuits (or axes) will be preserved and secondary injury will be reduced. We have been developing a systems-based, small-volume, fluid therapy comprising adenosine, lidocaine and magnesium (ALM) to treat sepsis and endotoxemia. Our early studies indicate that ALM therapy shifts the CNS from sympathetic to parasympathetic dominance, maintains cardiovascular-endothelial glycocalyx coupling, reduces inflammation, corrects coagulopathy, and maintains tissue O2 supply. Future research will investigate the potential translation to humans.

Fluid Responsiveness Is Associated with Successful Weaning after Liver Transplant Surgery

A positive fluid balance may evolve to fluid overload and associate with organ dysfunctions, weaning difficulties, and increased mortality in ICU patients. We explored whether individualized fluid management, assessing fluid responsiveness via a passive leg-raising maneuver (PLR) before a spontaneous breathing trial (SBT), is associated with less extubation failure in ventilated patients with a high fluid balance admitted to the ICU after liver transplantation (LT). We recruited 15 LT patients in 2023. Their postoperative fluid balance was +4476 {3697, 5722} mL. PLR maneuvers were conducted upon ICU admission (T1) and pre SBT (T2). Cardiac index (CI) changes were recorded before and after each SBT (T3). Seven patients were fluid-responsive at T1, and twelve were responsive at T2. No significant differences occurred in hemodynamic, respiratory, and perfusion parameters between the fluid-responsive and fluid-unresponsive patients at any time. Fluid-responsive patients at T1 and T2 increased their CI during SBT from 3.1 {2.8, 3.7} to 3.7 {3.4, 4.1} mL/min/m2 (p = 0.045). All fluid-responsive patients at T2 were extubated after the SBTs and consolidated extubation. Two out of three of the fluid-unresponsive patients experienced weaning difficulties. We concluded that fluid-responsive patients post LT may start weaning earlier and achieve successful extubation despite a high postoperative fluid balance. This highlights the profound impact of personalized assessments of cardiovascular state on critical surgical patients.

Dynamic monitoring tools for patients admitted to the emergency department with circulatory failure: narrative review with panel-based recommendations

Intravenous fluid therapy is commonly administered in the emergency department (ED). Despite the deleterious potential of over- and under-resuscitation, professional society guidelines continue to recommend administering a fixed volume of fluid in initial resuscitation. Predicting whether a specific patient will respond to fluid therapy remains one of the most important, but challenging questions that ED clinicians face in clinical practice. Surrogate parameters (i.e. blood pressure and heart rate), are widely used in usual care to estimate changes in stroke volume (SV). Due to their inadequacy in estimating SV, noninvasive techniques (e.g. bioreactance, echocardiography, noninvasive finger cuff technology), have been proposed as a more accurate and readily deployable method for assessing flow and preload responsiveness. Dynamic monitoring systems based on cardiac preload challenge and assessment of SV, by using noninvasive and continuous methods, provide more accurate, feasible, efficient, and reasonably accurate strategy for prediction of fluid responsiveness than static measurements. In this article, we aimed to analyze the different methods currently available for dynamic monitoring of preload responsiveness.

Fluid Management in Acute Respiratory Failure

Fluid management in acute respiratory failure is an area of uncertainty requiring a delicate balance of resuscitation and fluid removal to manage hypoperfusion and avoidance of hypoxemia. Overall, a restrictive fluid strategy (minimizing fluid administration) and careful attention to overall fluid balance may be beneficial after initial resuscitation and does not have major side effects. Further studies are needed to improve our understanding of patients who will benefit from a restrictive or liberal fluid management strategy.

Geo-economic Influence on the Effect of Fluid Volume for Sepsis Resuscitation: A Meta-Analysis

Rationale: Sepsis management relies on fluid resuscitation avoiding fluid overload and its related organ congestion. Objectives: To explore the influence of country income group on risk-benefit balance of fluid management strategies in sepsis. Methods: We searched e-databases for all randomized controlled trials on fluid resuscitation in patients with sepsis or septic shock up to January 2023, excluding studies on hypertonic fluids, colloids, and depletion-based interventions. The effect of fluid strategies (higher versus lower volumes) on mortality was analyzed per income group (i.e., low- and middle-income countries [LMICs] or high-income countries [HICs]). Measurements and Main Results: Twenty-nine studies (11,798 patients) were included in the meta-analysis. There was a numerically higher mortality in studies of LMICs as compared with those of HICs: median, 37% (interquartile range [IQR]: 26-41) versus 29% (IQR: 17-38; P = 0.06). Income group significantly interacted with the effect of fluid volume on mortality: Higher fluid volume was associated with higher mortality in LMICs but not in HICs: odds ratio (OR), 1.47; 95% confidence interval (95% CI): 1.14-1.90 versus 1.00 (95% CI: 0.87-1.16), P = 0.01 for subgroup differences. Higher fluid volume was associated with increased need for mechanical ventilation in LMICs (OR, 1.24 [95% CI: 1.08-1.43]) but not in HICs (OR, 1.02 [95% CI: 0.80-1.29]). Self-reported access to mechanical ventilation also significantly influenced the effect of fluid volume on mortality, which increased with higher volumes only in settings with limited access to mechanical ventilation (OR: 1.45 [95% CI: 1.09-1.93] vs. 1.09 [95% CI: 0.93-1.28], P = 0.02 for subgroup differences). Conclusions: In sepsis trials, the effect of fluid resuscitation approach differed by setting, with higher volume of fluid resuscitation associated with increased mortality in LMICs and in settings with restricted access to mechanical ventilation. The precise reason for these differences is unclear and may be attributable in part to resource constraints, participant variation between trials, or other unmeasured factors.

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.

Towards the personalization of septic shock resuscitation: the fundamentals of ANDROMEDA-SHOCK-2 trial

Septic shock is a highly lethal and prevalent disease. Progressive circulatory dysfunction leads to tissue hypoperfusion and hypoxia, eventually evolving to multiorgan dysfunction and death. Prompt resuscitation may revert these pathogenic mechanisms, restoring oxygen delivery and organ function. High heterogeneity exists among the determinants of circulatory dysfunction in septic shock, and current algorithms provide a stepwise and standardized approach to conduct resuscitation. This review provides the pathophysiological and clinical rationale behind ANDROMEDA-SHOCK-2, an ongoing multicenter randomized controlled trial that aims to compare a personalized resuscitation strategy based on clinical phenotyping and peripheral perfusion assessment, versus standard of care, in early septic shock resuscitation.

Surviving Sepsis Campaign Research Priorities 2023

OBJECTIVES

To identify research priorities in the management, epidemiology, outcome, and pathophysiology of sepsis and septic shock.

DESIGN

Shortly after publication of the most recent Surviving Sepsis Campaign Guidelines, the Surviving Sepsis Research Committee, a multiprofessional group of 16 international experts representing the European Society of Intensive Care Medicine and the Society of Critical Care Medicine, convened virtually and iteratively developed the article and recommendations, which represents an update from the 2018 Surviving Sepsis Campaign Research Priorities.

METHODS

Each task force member submitted five research questions on any sepsis-related subject. Committee members then independently ranked their top three priorities from the list generated. The highest rated clinical and basic science questions were developed into the current article.

RESULTS

A total of 81 questions were submitted. After merging similar questions, there were 34 clinical and ten basic science research questions submitted for voting. The five top clinical priorities were as follows: 1) what is the best strategy for screening and identification of patients with sepsis, and can predictive modeling assist in real-time recognition of sepsis? 2) what causes organ injury and dysfunction in sepsis, how should it be defined, and how can it be detected? 3) how should fluid resuscitation be individualized initially and beyond? 4) what is the best vasopressor approach for treating the different phases of septic shock? and 5) can a personalized/precision medicine approach identify optimal therapies to improve patient outcomes? The five top basic science priorities were as follows: 1) How can we improve animal models so that they more closely resemble sepsis in humans? 2) What outcome variables maximize correlations between human sepsis and animal models and are therefore most appropriate to use in both? 3) How does sepsis affect the brain, and how do sepsis-induced brain alterations contribute to organ dysfunction? How does sepsis affect interactions between neural, endocrine, and immune systems? 4) How does the microbiome affect sepsis pathobiology? 5) How do genetics and epigenetics influence the development of sepsis, the course of sepsis and the response to treatments for sepsis?

CONCLUSIONS

Knowledge advances in multiple clinical domains have been incorporated in progressive iterations of the Surviving Sepsis Campaign guidelines, allowing for evidence-based recommendations for short- and long-term management of sepsis. However, the strength of existing evidence is modest with significant knowledge gaps and mortality from sepsis remains high. The priorities identified represent a roadmap for research in sepsis and septic shock.

The correlation between carotid artery Doppler and stroke volume during central blood volume loss and resuscitation

BACKGROUND

Using peripheral arteries to infer central hemodynamics is common among hemodynamic monitors. Doppler ultrasound of the common carotid artery has been used in this manner with conflicting results. We investigated the relationship between changing common carotid artery Doppler measures and stroke volume (SV), hypothesizing that more consecutively-averaged cardiac cycles would improve SV-carotid Doppler correlation.

METHODS

Twenty-seven healthy volunteers were recruited and studied in a physiology laboratory. Carotid artery Doppler pulse was measured with a wearable, wireless ultrasound during central hypovolemia and resuscitation induced by a stepped lower body negative pressure protocol. The change in maximum velocity time integral (VTI) and corrected flow time of the carotid artery (ccFT) were compared with changing SV using repeated measures correlation.

RESULTS

In total, 73,431 cardiac cycles were compared across 27 subjects. There was a strong linear correlation between changing SV and carotid Doppler measures during simulated hemorrhage (repeated-measures linear correlation [Rrm ]=0.91 for VTI; 0.88 for ccFT). This relationship improved with larger numbers of consecutively-averaged cardiac cycles. For ccFT, beyond four consecutively-averaged cardiac cycles the correlation coefficient remained strong (i.e., Rrm of at least 0.80). For VTI, the correlation coefficient with SV was strong for any number of averaged cardiac cycles. For both ccFT and VTI, Rrm remained stable around 25 consecutively-averaged cardiac cycles.

CONCLUSIONS

There was a strong linear correlation between changing SV and carotid Doppler measures during central blood volume loss. The strength of this relationship was dependent upon the number of consecutively-averaged cardiac cycles.

The left ventricular outflow tract and carotid artery velocity time integrals

The left ventricular outflow tract velocity time integral (LVOT VTI) is commonly used in the intensive care unit as a measure of stroke volume (SV) and how the SV changes in response to an intervention; therefore, the LVOT VTI is used to guide intravenous fluid management. Various peripheral Doppler surrogates are proposed to infer the LVOT VTI (e.g., measures from the common carotid artery). A recently-described, novel method of insonation has an excellent ability to detect change in the LVOT VTI. This approach raises important facets of Doppler flow and insonation error, as well as the general principles at play when using a peripheral artery to infer changes from the left ventricle. Relating the VTI of a peripheral artery to the LVOT VTI was recently described mathematically and may help clinicians think about the Doppler relationship between central and peripheral flow.

Blood pressure response to clonidine in children with short stature is correlated with postural characteristics: a retrospective cross-sectional study

BACKGROUND

Clonidine stimulation test has been widely used in the diagnosis of growth hormone deficiency in children with short stature with a high level of reliability. However, it may cause hypotension, which usually appears as headache, dizziness, bradycardia, and even syncope. It is well known that elevating the beds to make patients' feet above their cardiac level might relieve this discomfort. However, the real efficiency of this method remains to be proved while the best angle for the elevated bed is still unclear.

METHODS

A total of 1200 children with short stature were enrolled in this retrospective cross-sectional study. Age, gender, weight, and basic systolic and diastolic blood pressure were collected. Blood pressure at 1, 2, 3, and 4 h after stimulation tests were recorded. The participants were divided into 3 groups based on the angles of the elevated foot of their beds named 0°, 20°, and 40° groups.

RESULTS

At one hour after the commencement of the tests, participants lying on the elevated beds showed a higher mean increase on the change of pulse pressure. The difference in the angles of the elevated beds did not show statistical significance compared with those who did not elevate their beds (0.13 vs. 2.83, P = 0.001; 0.13 vs. 2.18, P = 0.005; 2.83 vs. 2.18, P = 0.369). When it came to 4 h after the tests began, participants whose beds were elevated at an angle around 20° had a significantly higher mean increase in the change of pulse pressure values compared with those whose beds were elevated at an angle around 40° (1.46 vs. -0.05, P = 0.042).

CONCLUSION

Elevating the foot of the beds of the patients who are undergoing clonidine stimulation tests at an angle of 20°might be a good choice to alleviate the hypotension caused by the tests.

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.

Clinical outcomes of a prospective randomized comparison of bioreactance monitoring versus pulse-contour analysis in a stroke-volume based goal-directed fluid resuscitation protocol in brain-dead organ donors

Eighty percent of brain-dead (BD) organ donors develop hypotension and are frequently hypovolemic. Fluid resuscitation in a BD donor is controversial. We have previously published our 4-h goal-directed stroke volume (SV)-based fluid resuscitation protocol which significantly decreased time on vasopressors and increased transplanting four or more organs. The SV was measured by pulse-contour analysis (PCA) or an esophageal doppler monitor, both of which are invasive. Thoracic bioreactance (BR) is a non-invasive portable technology that measures SV but has not been studied in BD donors. We performed a randomized prospective comparative study of BR versus PCA technology in our fluid resuscitation protocol in BD donors. Eighty-four donors (53.1%) were randomized to BR and 74 donors to PCA (46.8%). The two groups were well matched based on 24 demographic, social, and initial laboratory factors, without any significant differences between them. There was no difference in the intravenous fluid infused over the 4-h study period [BR 2271 ± 823 vs. PCA 2230 ± 962 mL; p = .77]. There was no difference in the time to wean off vasopressors [BR 108.8 ± 61.8 vs. PCA 150.0 ± 68 min p = .07], nor in the number of donors off vasopressors at the end of the protocol [BR 16 (28.6%) vs. PCA 15 (29.4%); p = .92]. There was no difference in the total number of organs transplanted per donor [BR 3.25 ± 1.77 vs. PCA 3.22 ± 1.75; p = .90], nor in any individual organ transplanted. BR was equivalent to PCA in clinical outcomes and provides a simple, non-invasive, portable technology to monitor fluid resuscitation in organ donors.

Inferior vena cava ultrasound and other techniques for assessment of intravascular and extravascular volume: an update

Goals of volume management are to accurately assess intravascular and extravascular volume and predict response to volume administration, vasopressor support or volume removal. Data are reviewed that support the following: (i) Dynamic parameters reliably guide volume administration and may improve clinical outcomes compared with static parameters, but some are invasive or only validated with mechanical ventilation without spontaneous breathing. (ii) Ultrasound visualization of inferior vena cava (IVC) diameter variations with respiration reliably assesses intravascular volume and predicts volume responsiveness. (iii) Although physiology of IVC respiratory variations differs with mechanical ventilation and spontaneous breathing, the IVC collapsibility index (CI) and distensibility index are interconvertible. (iv) Prediction of volume responsiveness by IVC CI is comparable for mechanical ventilation and spontaneous breathing patients. (v) Respiratory variations of subclavian/proximal axillary and internal jugular veins by ultrasound are alternative sites, with comparable reliability. (vi) Data support clinical applicability of IVC CI to predict hypotension with anesthesia, guide ultrafiltration goals, predict dry weight, predict intra-dialytic hypotension and assess acute decompensated heart failure. (vii) IVC ultrasound may complement ultrasound of heart and lungs, and abdominal organs for venous congestion, for assessing and managing volume overload and deresuscitation, renal failure and shock. (viii) IVC ultrasound has limitations including inadequate visualization. Ultrasound data should always be interpreted in clinical context. Additional studies are required to further assess and validate the role of bedside ultrasonography in clinical care.

The Role of Pre- and Post-Transplant Hydration Status in Kidney Graft Recovery and One-Year Function

Background and Objectives: Early improvements to graft function are crucial for good outcomes in kidney transplantation (kTx). Various factors can influence early graft function. This study aimed to evaluate the pre- and post-transplant hydration statuses of kTx recipients using bioimpedance analysis (BIA) and lung ultrasonography (LUS) and to investigate the hydration status' relationship with the function of the transplanted kidney during the first year after transplantation. Materials and Methods: This observational prospective cohort study included deceased kidney recipients transplanted in the Hospital of the Lithuanian University of Health Sciences between September 2016 and January 2023. BIA and LUS were performed before transplantation, on days 3 and 7, and at discharge. Data on recipient and donor clinical characteristics were collected. Graft function was evaluated according to the serum creatinine reduction ratio and the need for dialysis. Hydration status was evaluated by calculating B-lines (BL) on LUS and the ratio of extracellular/total body water on BIA. Results: Ninety-eight kTx recipients were included in the study. Patients with immediate graft function (IGF) were compared to those with slow or delayed graft function (SGF + DGF). Recipients in the SGF + DGF group had a higher sum of BL on LUS before transplantation. After transplantation in early postoperative follow-up, both groups showed hyperhydration as determined by BIA and LUS. After one year, recipients with no BL before transplantation had better graft function than those with BL. Logistic regression analysis showed that having more than one BL in LUS was associated with a 2.5 times higher risk of SGF or DGF after transplantation. Conclusions: This study found that lung congestion detected by LUS before kTx was associated with slower graft recovery and worse kidney function after 1 year. Meanwhile, the hyperhydration status detected by BIA analysis did not correlate with the function of the transplanted kidney.

Surviving Sepsis After Burn Campaign

INTRODUCTION

The Surviving Sepsis Campaign was developed to improve outcomes for all patients with sepsis. Despite sepsis being the primary cause of death after thermal injury, burns have always been excluded from the Surviving Sepsis efforts. To improve sepsis outcomes in burn patients, an international group of burn experts developed the Surviving Sepsis After Burn Campaign (SSABC) as a testable guideline to improve burn sepsis outcomes.

METHODS

The International Society for Burn Injuries (ISBI) reached out to regional or national burn organizations to recommend members to participate in the program. Two members of the ISBI developed specific "patient/population, intervention, comparison and outcome" (PICO) questions that paralleled the 2021 Surviving Sepsis Campaign [1]. SSABC participants were asked to search the current literature and rate its quality for each topic. At the Congress of the ISBI, in Guadalajara, Mexico, August 28, 2022, a majority of the participants met to create "statements" based on the literature. The "summary statements" were then sent to all members for comment with the hope of developing an 80% consensus. After four reviews, a consensus statement for each topic was created or "no consensus" was reported.

RESULTS

The committee developed sixty statements within fourteen topics that provide guidance for the early treatment of sepsis in burn patients. These statements should be used to improve the care of sepsis in burn patients. The statements should not be considered as "static" comments but should rather be used as guidelines for future testing of the best treatments for sepsis in burn patients. They should be updated on a regular basis.

CONCLUSION

Members of the burn community from the around the world have developed the Surviving Sepsis After Burn Campaign guidelines with the goal of improving the outcome of sepsis in burn patients.

Lower vs Higher Fluid Volumes in Adult Patients With Sepsis: An Updated Systematic Review With Meta-Analysis and Trial Sequential Analysis

BACKGROUND

IV fluids are recommended for adults with sepsis. However, the optimal strategy for IV fluid management in sepsis is unknown, and clinical equipoise exists.

RESEARCH QUESTION

Do lower vs higher fluid volumes improve patient-important outcomes in adult patients with sepsis?

STUDY DESIGN AND METHODS

We updated a systematic review with meta-analysis and trial sequential analysis of randomized clinical trials assessing lower vs higher IV fluid volumes in adult patients with sepsis. The coprimary outcomes were all-cause mortality, serious adverse events, and health-related quality of life. We followed the recommendations from the Cochrane Handbook and used the Grading of Recommendations Assessment, Development and Evaluation approach. Primary conclusions were based on trials with low risk of bias if available.

RESULTS

We included 13 trials (N = 4,006) with four trials (n = 3,385) added to this update. The meta-analysis of all-cause mortality in eight trials with low risk of bias showed a relative risk of 0.99 (97% CI, 0.89-1.10; moderate certainty evidence). Six trials with predefined definitions of serious adverse events showed a relative risk of 0.95 (97% CI, 0.83-1.07; low certainty evidence). Health-related quality of life was not reported.

INTERPRETATION

Among adult patients with sepsis, lower IV fluid volumes probably result in little to no difference in all-cause mortality compared with higher IV fluid volumes, but the interpretation is limited by imprecision in the estimate, which does not exclude potential benefit or harm. Similarly, the evidence suggests lower IV fluid volumes result in little to no difference in serious adverse events. No trials reported on health-related quality of life.

TRIAL REGISTRATION

PROSPERO; No.: CRD42022312572; URL: https://www.crd.york.ac.uk/prospero/.

The Ins and Outs of IV Fluids in Hemodynamic Resuscitation

OBJECTIVES

Concise definitive review of the physiology of IV fluid (IVF) use in critically ill patients.

DATA SOURCES

Available literature on PubMed and MEDLINE databases.

STUDY SELECTION

Basic physiology studies, observational studies, clinical trials, and reviews addressing the physiology of IVF and their use in the critically ill were included.

DATA EXTRACTION

None.

DATA SYNTHESIS

We combine clinical and physiologic studies to form a framework for understanding rational and science-based use of fluids and electrolytes.

CONCLUSIONS

IVF administration is among the most common interventions for critically ill patients. IVF can be classified as crystalloids or colloids, and most crystalloids are sodium salts. They are frequently used to improve hemodynamics during shock states. Many recent clinical trials have sought to understand which kind of IVF might lead to better patient outcomes, especially in sepsis. Rational use of IVF rests on understanding the physiology of the shock state and what to expect IVF will act in those settings. Many questions remain unanswered, and future research should include a physiologic understanding of IVF in study design.

Proceedings of the 2022 UAB CRRT Academy: Non-Invasive Hemodynamic Monitoring to Guide Fluid Removal with CRRT and Proliferation of Extracorporeal Blood Purification Devices

In 2022, we celebrated the 15th anniversary of the University of Alabama at Birmingham (UAB) Continuous Renal Replacement Therapy (CRRT) Academy, a 2-day conference attended yearly by an international audience of over 100 nephrology, critical care, and multidisciplinary trainees and practitioners. This year, we introduce the proceedings of the UAB CRRT Academy, a yearly review of select emerging topics in the field of critical care nephrology that feature prominently in the conference. First, we review the rapidly evolving field of non-invasive hemodynamic monitoring and its potential to guide fluid removal by renal replacement therapy (RRT). We begin by summarizing the accumulating data associating fluid overload with harm in critical illness and the potential for harm from end-organ hypoperfusion caused by excessive fluid removal with RRT, underscoring the importance of accurate, dynamic assessment of volume status. We describe four applications of point-of-care ultrasound used to identify patients in need of urgent fluid removal or likely to tolerate fluid removal: lung ultrasound, inferior vena cava ultrasound, venous excess ultrasonography, and Doppler of the left ventricular outflow track to estimate stroke volume. We briefly introduce other minimally invasive hemodynamic monitoring technologies before concluding that additional prospective data are urgently needed to adapt these technologies to the specific task of fluid removal by RRT and to learn how best to integrate them into practical fluid-management strategies. Second, we focus on the growth of novel extracorporeal blood purification devices, starting with brief reviews of the inflammatory underpinnings of multiorgan dysfunction and the specific applications of pathogen, endotoxin, and/or cytokine removal and immunomodulation. Finally, we review a series of specific adsorptive technologies, several of which have seen substantial clinical use during the COVID-19 pandemic, describing their mechanisms of target removal, the limited existing data supporting their efficacy, ongoing and future studies, and the need for additional prospective trials.

The Effects of Restrictive Fluid Resuscitation on the Clinical Outcomes in Patients with Sepsis or Septic Shock: A Meta-Analysis of Randomized-Controlled Trials

This study aims to assess the impact of a restrictive resuscitation strategy on the outcomes of patients with sepsis and septic shock. This meta-analysis was conducted in accordance with the recommendations from the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) guidelines. A systematic search was performed in databases, including PubMed, Web of Science, EMBASE, and the Cochrane Library, covering the period from the inception of the database to August 2023, with no limitations on the language of publication. Outcomes assessed in the meta-analysis included mortality, duration of intensive care unit (ICU) stay in days, duration of mechanical ventilation in days, acute kidney injury (AKI) or the need for renal replacement therapy (RRT), and length of hospital stay in days. Overall, 12 studies met the inclusion criteria and were included in the present meta-analysis. The findings of this study indicate that although the risk of mortality was lower in fluid restriction compared to the control group, the difference was statistically insignificant (risk ratio (RR): 0.98; 95% confidence interval (CI): 0.9-1.05; P value: 0.61). Additionally, the duration of mechanical ventilation was significantly shorter in the restrictive fluid group compared to its counterparts (mean difference (MD): -1.02; 95% CI: -1.65 to -0.38; P value: 0.003). There were no significant differences found in relation to the duration of ICU stays, the incidence of AKI, the requirement for RRT, or the length of hospital stays measured in days.

Society for Maternal-Fetal Medicine Consult Series #67: Maternal sepsis

Maternal sepsis is a significant cause of maternal morbidity and mortality, and is a potentially preventable cause of maternal death. This Consult aims to summarize what is known about sepsis and provide guidance for the management of sepsis during pregnancy and the postpartum period. Most studies cited are from the nonpregnant population, but where available, pregnancy data are included. The following are the Society for Maternal-Fetal Medicine recommendations: (1) we recommend that clinicians consider the diagnosis of sepsis in pregnant or postpartum patients with otherwise unexplained end-organ damage in the presence of a suspected or confirmed infectious process, regardless of the presence of fever (GRADE 1C); (2) we recommend that sepsis and septic shock in pregnancy be considered medical emergencies and that treatment and resuscitation begin immediately (Best Practice); (3) we recommend that hospitals and health systems use a performance improvement program for sepsis in pregnancy with sepsis screening tools and metrics (GRADE 1B); (4) we recommend that institutions develop their own procedures and protocols for the detection of maternal sepsis, avoiding the use of a single screening tool alone (GRADE 1B); (5) we recommend obtaining tests to evaluate for infectious and noninfectious causes of life-threatening organ dysfunction in pregnant and postpartum patients with possible sepsis (Best Practice); (6) we recommend that an evaluation for infectious causes in pregnant or postpartum patients in whom sepsis is suspected or identified includes appropriate microbiologic cultures, including blood, before starting antimicrobial therapy, as long as there are no substantial delays in timely administration of antibiotics (Best Practice); (7) we recommend obtaining a serum lactate level in pregnant or postpartum patients in whom sepsis is suspected or identified (GRADE 1B); (8) in pregnant or postpartum patients with septic shock or a high likelihood of sepsis, we recommend administration of empiric broad-spectrum antimicrobial therapy, ideally within 1 hour of recognition (GRADE 1C); (9) after a diagnosis of sepsis in pregnancy is made, we recommend rapid identification or exclusion of an anatomic source of infection and emergency source control when indicated (Best Practice); (10) we recommend early intravenous administration (within the first 3 hours) of 1 to 2 L of balanced crystalloid solutions in sepsis complicated by hypotension or suspected organ hypoperfusion (GRADE 1C); (11) we recommend the use of a balanced crystalloid solution as a first-line fluid for resuscitation in pregnant and postpartum patients with sepsis or septic shock (GRADE 1B); (12) we recommend against the use of starches or gelatin for resuscitation in pregnant and postpartum patients with sepsis or septic shock (GRADE 1A); (13) we recommend ongoing, detailed evaluation of the patient's response to fluid resuscitation guided by dynamic measures of preload (GRADE 1B); (14) we recommend the use of norepinephrine as the first-line vasopressor during pregnancy and the postpartum period with septic shock (GRADE 1C); (15) we suggest using intravenous corticosteroids in pregnant or postpartum patients with septic shock who continue to require vasopressor therapy (GRADE 2B); (16) because of an increased risk of venous thromboembolism in sepsis and septic shock, we recommend the use of pharmacologic venous thromboembolism prophylaxis in pregnant and postpartum patients in septic shock (GRADE 1B); (17) we suggest initiating insulin therapy at a glucose level >180 mg/dL in critically ill pregnant patients with sepsis (GRADE 2C); (18) if a uterine source for sepsis is suspected or confirmed, we recommend prompt delivery or evacuation of uterine contents to achieve source control, regardless of gestational age (GRADE 1C); and (19) because of an increased risk of physical, cognitive, and emotional problems in survivors of sepsis and septic shock, we recommend ongoing comprehensive support for pregnant and postpartum sepsis survivors and their families (Best Practice).

Inspiratory effort impacts the accuracy of pulse pressure variations for fluid responsiveness prediction in mechanically ventilated patients with spontaneous breathing activity: a prospective cohort study

BACKGROUND

Pulse pressure variation (PPV) is unreliable in predicting fluid responsiveness (FR) in patients receiving mechanical ventilation with spontaneous breathing activity. Whether PPV can be valuable for predicting FR in patients with low inspiratory effort is unknown. We aimed to investigate whether PPV can be valuable in patients with low inspiratory effort.

METHODS

This prospective study was conducted in an intensive care unit at a university hospital and included acute circulatory failure patients receiving volume-controlled ventilation with spontaneous breathing activity. Hemodynamic measurements were collected before and after a fluid challenge. The degree of inspiratory effort was assessed using airway occlusion pressure (P0.1) and airway pressure swing during a whole breath occlusion (ΔPocc) before fluid challenge. Patients were classified as fluid responders if their cardiac output increased by ≥ 10%. Areas under receiver operating characteristic (AUROC) curves and gray zone approach were used to assess the predictive performance of PPV.

RESULTS

Among the 189 included patients, 53 (28.0%) were defined as responders. A PPV > 9.5% enabled to predict FR with an AUROC of 0.79 (0.67-0.83) in the whole population. The predictive performance of PPV differed significantly in groups stratified by the median value of P0.1 (P0.1 < 1.5 cmH2O and P0.1 ≥ 1.5 cmH2O), but not in groups stratified by the median value of ΔPocc (ΔPocc < - 9.8 cmH2O and ΔPocc ≥ - 9.8 cmH2O). Specifically, in patients with P0.1 < 1.5 cmH2O, PPV was associated with an AUROC of 0.90 (0.82-0.99) compared with 0.68 (0.57-0.79) otherwise (p = 0.0016). The cut-off values of PPV were 10.5% and 9.5%, respectively. Besides, patients with P0.1 < 1.5 cmH2O had a narrow gray zone (10.5-11.5%) compared to patients with P0.1 ≥ 1.5 cmH2O (8.5-16.5%).

CONCLUSIONS

PPV is reliable in predicting FR in patients who received controlled ventilation with low spontaneous effort, defined as P0.1 < 1.5 cmH2O. Trial registration NCT04802668. Registered 6 February 2021, https://clinicaltrials.gov/ct2/show/record/NCT04802668.

Pulmonary, circulatory and renal considerations in the early postoperative management of the lung transplant recipient

Lung transplantation volumes and survival rates continue to increase worldwide. Primary graft dysfunction (PGD) and acute kidney injury (AKI) are common early postoperative complications that significantly affect short-term mortality and long-term outcomes. These conditions share overlapping risk factors and are driven, in part, by circulatory derangements. The prevalence of severe PGD is up to 20% and is the leading cause of early death. Patients with pulmonary hypertension are at a higher risk. Prevention and management are based on principles learned from acute lung injury of other causes. Targeting the lowest effective cardiac filling pressure will reduce alveolar edema formation in the setting of increased pulmonary capillary permeability. AKI is reported in up to one-half of lung transplant recipients and is strongly associated with one-year mortality as well as long-term chronic kidney disease. Optimization of renal perfusion is critical to reduce the incidence and severity of AKI. In this review, we highlight key early post-transplant pulmonary, circulatory, and renal perturbations and our center's management approach.

Feasibility Assessment of a Biomarker-Guided Kidney-Sparing Sepsis Bundle: The Limiting Acute Kidney Injury Progression In Sepsis Trial

OBJECTIVES

To determine the feasibility, safety, and efficacy of a biomarker-guided implementation of a kidney-sparing sepsis bundle (KSSB) of care in comparison with standard of care (SOC) on clinical outcomes in patients with sepsis.

DESIGN

Adaptive, multicenter, randomized clinical trial.

SETTING

Five University Hospitals in Europe and North America.

PATIENTS

Adult patients, admitted to the ICU with an indwelling urinary catheter and diagnosis of sepsis or septic shock, without acute kidney injury (acute kidney injury) stage 2 or 3 or chronic kidney disease.

INTERVENTIONS

A three-level KSSB based on Kidney Disease: Improving Global Outcomes (KDIGOs) recommendations guided by serial measurements of urinary tissue inhibitor of metalloproteinases-2 and insulin-like growth factor-binding protein 7 used as a combined biomarker [TIMP2]•[IGFBP7].

MEASUREMENTS AND MAIN RESULTS

The trial was stopped for low enrollment related to the COVID-19 pandemic. Nineteen patients enrolled in five sites over 12 months were randomized to the SOC (n = 8, 42.0%) or intervention (n = 11, 58.0%). The primary outcome was feasibility, and key secondary outcomes were safety and efficacy. Adherence to protocol in patients assigned to the first two levels of KSSB was 15 of 19 (81.8%) and 19 of 19 (100%) but was 1 of 4 (25%) for level 3 KSSB. Serious adverse events were more frequent in the intervention arm (4/11, 36.4%) than in the control arm (1/8, 12.5%), but none were related to study interventions. The secondary efficacy outcome was a composite of death, dialysis, or progression of greater than or equal to 2 stages of acute kidney injury within 72 hours after enrollment and was reached by 3 of 8 (37.5%) patients in the control arm, and 0 of 11 (0%) patients in the intervention arm. In the control arm, two patients experienced progression of acute kidney injury, and one patient died.

CONCLUSIONS

Although the COVID-19 pandemic impeded recruitment, the actual implementation of a therapeutic strategy that deploys a KDIGO-based KSSB of care guided by risk stratification using urinary [TIMP2]•[IGFBP7] seems feasible and appears to be safe in patients with sepsis.

Simultaneous venous-arterial Doppler during preload augmentation: illustrating the Doppler Starling curve

Providing intravenous (IV) fluids to a patient with signs or symptoms of hypoperfusion is common. However, evaluating the IV fluid 'dose-response' curve of the heart is elusive. Two patients were studied in the emergency department with a wireless, wearable Doppler ultrasound system. Change in the common carotid arterial and internal jugular Doppler spectrograms were simultaneously obtained as surrogates of left ventricular stroke volume (SV) and central venous pressure (CVP), respectively. Both patients initially had low CVP jugular venous Doppler spectrograms. With preload augmentation, only one patient had arterial Doppler measures indicative of significant SV augmentation (i.e., 'fluid responsive'). The other patient manifested diminishing arterial response, suggesting depressed SV (i.e., 'fluid unresponsive') with evidence of ventricular asynchrony. In this short communication, we describe how a wireless, wearable Doppler ultrasound simultaneously tracks surrogates of cardiac preload and output within a 'Doppler Starling curve' framework; implications for IV fluid dosing are discussed.

Physicians' Clinical Behavior During Fluid Evaluation Encounters

We sought to identify factors affecting physicians' cognition and clinical behavior when evaluating patients that may need fluid therapy.

BACKGROUND

Proponents of dynamic fluid responsiveness testing advocate measuring cardiac output or stroke volume after a maneuver to prove that further fluids will increase cardiac output. However, surveys suggest that fluid therapy in clinical practice is often given without prior responsiveness testing.

DESIGN

Thematic analysis of face-to-face structured interviews.

SETTING

ICUs and medical-surgical wards in acute care hospitals.

SUBJECTS

Intensivists and hospitalist physicians.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We conducted 43 interviews with experienced physicians in 19 hospitals. Hospitalized patients with hypotension, tachycardia, oliguria, or elevated serum lactate are commonly seen by physicians who weigh the risks and benefits of more fluid therapy. Encounters are often with unfamiliar patients and evaluation and decisions are completed quickly without involving other physicians. Dynamic testing for fluid responsiveness is used much less often than static methods and fluid boluses are often ordered with no testing at all. This approach is rationalized by factors that discourage dynamic testing: unavailability of equipment, time to obtain test results, or lack of expertise in obtaining valid data. Two mental calculations are particularly influential: physicians' estimate of the base rate of fluid responsiveness (determined by physical examination, chart review, and previous responses to fluid boluses) and physicians' perception of patient harm if 500 or 1,000 mL fluid boluses are ordered. When the perception of harm is low, physicians use heuristics that rationalize skipping dynamic testing.

LIMITATIONS

Geographic limitation to hospitals in Minnesota, United States.

CONCLUSIONS

If dynamic responsiveness testing is to be used more often in routine clinical practice, physicians must be more convinced of the benefits of dynamic testing, that they can obtain valid results quickly and believe that even small fluid boluses harm their patients.

Representation Learning and Spectral Clustering for the Development and External Validation of Dynamic Sepsis Phenotypes: Observational Cohort Study

BACKGROUND

Recent attempts at clinical phenotyping for sepsis have shown promise in identifying groups of patients with distinct treatment responses. Nonetheless, the replicability and actionability of these phenotypes remain an issue because the patient trajectory is a function of both the patient's physiological state and the interventions they receive.

OBJECTIVE

We aimed to develop a novel approach for deriving clinical phenotypes using unsupervised learning and transition modeling.

METHODS

Forty commonly used clinical variables from the electronic health record were used as inputs to a feed-forward neural network trained to predict the onset of sepsis. Using spectral clustering on the representations from this network, we derived and validated consistent phenotypes across a diverse cohort of patients with sepsis. We modeled phenotype dynamics as a Markov decision process with transitions as a function of the patient's current state and the interventions they received.

RESULTS

Four consistent and distinct phenotypes were derived from over 11,500 adult patients who were admitted from the University of California, San Diego emergency department (ED) with sepsis between January 1, 2016, and January 31, 2020. Over 2000 adult patients admitted from the University of California, Irvine ED with sepsis between November 4, 2017, and August 4, 2022, were involved in the external validation. We demonstrate that sepsis phenotypes are not static and evolve in response to physiological factors and based on interventions. We show that roughly 45% of patients change phenotype membership within the first 6 hours of ED arrival. We observed consistent trends in patient dynamics as a function of interventions including early administration of antibiotics.

CONCLUSIONS

We derived and describe 4 sepsis phenotypes present within 6 hours of triage in the ED. We observe that the administration of a 30 mL/kg fluid bolus may be associated with worse outcomes in certain phenotypes, whereas prompt antimicrobial therapy is associated with improved outcomes.

Integrated ultrasonographic approach to evaluate fluid responsiveness in critically ill patients

In patients with acute circulatory failure, we tested the feasibility of the evaluation of the fluid-responsiveness (FR) by a combined approach with echocardiography and lung ultrasound. We enrolled 113 consecutive patients admitted to the Emergency Department High-Dependency Unit of Careggi University-Hospital from January 2015 to June 2020. We assessed: (1) inferior vena cava collapsibility index (IVCCI); (2) the variation of aortic flow (VTIAo) during the passive leg raising test (PLR); (3) the presence of interstitial syndrome by lung ultrasound. FR was defined as an increase in the VTIAo > 10% during PLR or IVCCI ≥ 40%. FR patients were treated with fluid and those non-FR with diuretics or vasopressors. The therapeutic strategy was reassessed after 12 h. The goal was to maintain the initial strategy. Among 56 FR patients, at lung ultrasound, 15 patients showed basal interstitial syndrome and 4 all-lung involvement. One fluid bolus was given to 51 patients. Among 57 non-FR patients, 26 patients showed interstitial syndrome at lung ultrasound (basal fields in 14, all lungs in 12). We administered diuretics to 21 patients and vasopressors to 4 subjects. We had to change the initial treatment plan in 9% non-FR patients and in 12% FR patients (p = NS). In the first 12 h after the evaluation, non-FR patients received significantly less fluids compared to those FR (1119 ± 410 vs 2010 ± 1254 ml, p < 0.001). The evaluation of the FR based on echocardiography and lung ultrasound was associated with the reduction in fluid administration for non-FR patients compared with those FR.

New Insights into the Fluid Management in Patients with Septic Shock

The importance of fluid resuscitation therapy during the early stages of sepsis management is a well-established principle. Current Surviving Sepsis Campaign (SSC) guidelines recommend the early administration of intravenous crystalloid fluids for sepsis-related hypotension or hyperlactatemia due to tissue hypoperfusion, within the first 3 h of resuscitation and suggest using balanced solutions (BSs) instead of normal saline (NS) for the management of patients with sepsis or septic shock. Studies comparing BS versus NS administration in septic patients have demonstrated that BSs are associated with better outcomes including decreased mortality. After initial resuscitation, fluid administration has to be judicious in order to avoid fluid overload, which has been associated with increased mortality, prolonged mechanical ventilation, and worsening of acute kidney injury. The "one size fits all" approach may be "convenient" but it should be avoided. Personalized fluid management, based on patient-specific hemodynamic indices, provides the foundations for better patient outcomes in the future. Although there is a consensus on the need for adequate fluid therapy in sepsis, the type, the amount of administered fluids, and the ideal fluid resuscitation strategy remain elusive. Well-designed large randomized controlled trials are certainly needed to compare fluid choices specifically in the septic patient, as there is currently limited evidence of low quality. This review aims to summarize the physiologic principles and current scientific evidence regarding fluid management in patients with sepsis, as well as to provide a comprehensive overview of the latest data on the optimal fluid administration strategy in sepsis.

Evolving Management Practices for Early Sepsis-induced Hypoperfusion: A Narrative Review

Sepsis causes significant morbidity and mortality worldwide. Resuscitation is a cornerstone of management. This review covers five areas of evolving practice in the management of early sepsis-induced hypoperfusion: fluid resuscitation volume, timing of vasopressor initiation, resuscitation targets, route of vasopressor administration, and use of invasive blood pressure monitoring. For each topic, we review the seminal evidence, discuss the evolution of practice over time, and highlight questions for additional research. Intravenous fluids are a core component of early sepsis resuscitation. However, with growing concerns about the harms of fluid, practice is evolving toward smaller-volume resuscitation, which is often paired with earlier vasopressor initiation. Large trials of fluid-restrictive, vasopressor-early strategies are providing more information about the safety and potential benefit of these approaches. Lowering blood pressure targets is a means to prevent fluid overload and reduce exposure to vasopressors; mean arterial pressure targets of 60-65 mm Hg appear to be safe, at least in older patients. With the trend toward earlier vasopressor initiation, the need for central administration of vasopressors has been questioned, and peripheral vasopressor use is increasing, although it is not universally accepted. Similarly, although guidelines suggest the use of invasive blood pressure monitoring with arterial catheters in patients receiving vasopressors, blood pressure cuffs are less invasive and often sufficient. Overall, the management of early sepsis-induced hypoperfusion is evolving toward fluid-sparing and less-invasive strategies. However, many questions remain, and additional data are needed to further optimize our approach to resuscitation.

Emerging concepts in the care of patients with cirrhosis and septic shock

Septic shock impacts approximately 6% of hospitalized patients with cirrhosis and is associated with high rates of morbidity and mortality. Although a number of landmark clinical trials have paved the way for incremental improvements in the diagnosis and management of septic shock in the general population, patients with cirrhosis have largely been excluded from these studies and critical knowledge gaps continue to impact the care of these individuals. In this review, we discuss nuances in the care of patients with cirrhosis and septic shock using a pathophysiology-based approach. We illustrate that septic shock may be challenging to diagnose in this population in the context of factors such as chronic hypotension, impaired lactate metabolism, and concomitant hepatic encephalopathy. Furthermore, we demonstrate that the application of routine interventions such as intravenous fluids, vasopressors, antibiotics, and steroids should be carefully considered among those with decompensated cirrhosis in light of hemodynamic, metabolic, hormonal, and immunologic disturbances. We propose that future research should include and characterize patients with cirrhosis in a systematic manner, and clinical practice guidelines may need to be refined accordingly.

Safety evaluation of smart scales, smart watches, and smart rings with bioimpedance technology shows evidence of potential interference in cardiac implantable electronic devices

BACKGROUND

Smart scales, smart watches, and smart rings with bioimpedance technology may create interference in patients with cardiac implantable electronic devices (CIEDs).

OBJECTIVES

The purpose of this study was to determine interference at CIEDs with simulations and benchtop testing, and to compare the results with maximum values defined in the ISO 14117 electromagnetic interference standard for these devices.

METHODS

The interference at pacing electrodes was determined by simulations on a male and a female computable model. A benchtop evaluation of representative CIEDs from 3 different manufacturers as specified in the ISO 14117 standard also was performed.

RESULTS

Simulations showed evidence of interference with voltage values exceeding threshold values defined in the ISO 14117 standard. The level of interference varied with the frequency and amplitude of the bioimpedance signal, and between male and female models. The level of interference generated with smart scale and smart rings simulations was lower than with smart watches. Across device manufacturers, generators demonstrated susceptibility to oversensing and pacing inhibition at different signal amplitudes and frequencies.

CONCLUSIONS

This study evaluated the safety of smart scales, smart watches, and smart rings with bioimpedance technology via simulation and testing. Our results indicate that these consumer electronic devices could interfere in patients with CIEDs. The present findings do not recommend the use of these devices in this population due to potential interference.

Relationship between peripheral ischemic microvascular reserve, persistent hyperlactatemia, and its temporal dynamics in sepsis: a post hoc study

OBJECTIVE

To measure the prognostic value of peripheral ischemic microvascular reserve in the context of persistent sepsis-induced hyperlactatemia and measure its influence on the temporal dynamics of lactate and the strength of association between these variables.

METHODS

This post hoc analysis of the peripheral perfusion index/postocclusive reactive hyperemia trial, an observational cohort study that enrolled patients with sepsis who persisted with lactate levels ≥ 2mmol/L after fluid resuscitation (with or without shock). Peripheral ischemic microvascular reserve was evaluated using the association of the peripheral perfusion index and postocclusive reactive hyperemia techniques. The cutoff point of ∆ peripheral perfusion index peak values (%) defined the groups with low (≤ 62%) and high peripheral ischemic microvascular reserve (> 62%).

RESULTS

A total of 108 consecutive patients with persistent sepsis-induced hyperlactatemia were studied. The high peripheral ischemic microvascular reserve group showed higher 28-day mortality than the low peripheral ischemic microvascular reserve group (p < 0.01). The temporal dynamics of lactate within the first 48 hours showed a rapid decrease in lactate levels in the low peripheral ischemic microvascular reserve group (p < 0.01). However, this result was not reproduced in the linear mixed effects model. A weak correlation between peripheral ischemic microvascular reserve (%) and lactate level (mmol/L) was observed within the first 24 hours (r = 0.23; p < 0.05).

CONCLUSION

The prognostic value of high peripheral ischemic microvascular reserve was confirmed in the context of persistent sepsis-induced hyperlactatemia. Although there was a weak positive correlation between peripheral ischemic microvascular reserve value and lactate level within the first 24 hours of sepsis diagnosis, the low peripheral ischemic microvascular reserve group appeared to have a faster decrease in lactate over the 48 hours of follow-up.

How I personalize fluid therapy in septic shock?

During septic shock, fluid therapy is aimed at increasing cardiac output and improving tissue oxygenation, but it poses two problems: it has inconsistent and transient efficacy, and it has many well-documented deleterious effects. We suggest that there is a place for its personalization according to the patient characteristics and the clinical situation, at all stages of circulatory failure. Regarding the choice of fluid for volume expansion, isotonic saline induces hyperchloremic acidosis, but only for very large volumes administered. We suggest that balanced solutions should be reserved for patients who have already received large volumes and in whom the chloremia is rising. The initial volume expansion, intended to compensate for the constant hypovolaemia in the initial phase of septic shock, cannot be adapted to the patient's weight only, as suggested by the Surviving Sepsis Campaign, but should also consider potential absolute hypovolemia induced by fluid losses. After the initial fluid infusion, preload responsiveness may rapidly disappear, and it should be assessed. The choice between tests used for this purpose depends on the presence or absence of mechanical ventilation, the monitoring in place and the risk of fluid accumulation. In non-intubated patients, the passive leg raising test and the mini-fluid challenge are suitable. In patients without cardiac output monitoring, tests like the tidal volume challenge, the passive leg raising test and the mini-fluid challenge can be used as they can be performed by measuring changes in pulse pressure variation, assessed through an arterial line. The mini-fluid challenge should not be repeated in patients who already received large volumes of fluids. The variables to assess fluid accumulation depend on the clinical condition. In acute respiratory distress syndrome, pulmonary arterial occlusion pressure, extravascular lung water and pulmonary vascular permeability index assess the risk of worsening alveolar oedema better than arterial oxygenation. In case of abdominal problems, the intra-abdominal pressure should be taken into account. Finally, fluid depletion in the de-escalation phase is considered in patients with significant fluid accumulation. Fluid removal can be guided by preload responsiveness testing, since haemodynamic deterioration is likely to occur in patients with a preload dependent state.

Development of a nomogram for predicting 90-day mortality in patients with sepsis-associated liver injury

The high mortality rate in sepsis patients is related to sepsis-associated liver injury (SALI). We sought to develop an accurate forecasting nomogram to estimate individual 90-day mortality in SALI patients. Data from 34,329 patients were extracted from the public Medical Information Mart for Intensive Care (MIMIC-IV) database. SALI was defined by total bilirubin (TBIL) > 2 mg/dL and the occurrence of an international normalized ratio (INR) > 1.5 in the presence of sepsis. Logistic regression analysis was performed to establish a prediction model called the nomogram based on the training set (n = 727), which was subsequently subjected to internal validation. Multivariate logistic regression analysis showed that SALI was an independent risk factor for mortality in patients with sepsis. The Kaplan‒Meier curves for 90-day survival were different between the SALI and non-SALI groups after propensity score matching (PSM) (log rank: P < 0.001 versus P = 0.038), regardless of PSM balance. The nomogram demonstrated better discrimination than the sequential organ failure assessment (SOFA) score, logistic organ dysfunction system (LODS) score, simplified acute physiology II (SAPS II) score, and Albumin-Bilirubin (ALBI) score in the training and validation sets, with areas under the receiver operating characteristic curve (AUROC) of 0.778 (95% CI 0.730-0.799, P < 0.001) and 0.804 (95% CI 0.713-0.820, P < 0.001), respectively. The calibration plot showed that the nomogram was sufficiently successful to predict the probability of 90-day mortality in both groups. The DCA of the nomogram demonstrated a higher net benefit regarding clinical usefulness than SOFA, LODS, SAPSII, and ALBI scores in the two groups. The nomogram performs exceptionally well in predicting the 90-day mortality rate in SALI patients, which can be used to assess the prognosis of patients with SALI and may assist in guiding clinical practice to enhance patient outcomes.

Indications, Clinical Impact, and Complications of Critical Care Transesophageal Echocardiography: A Scoping Review

BACKGROUND

Critical care transesophageal echocardiography (ccTEE) is an increasingly popular tool used by intensivists to characterize and manage hemodynamics at the bedside. Its usage appears to be driven by expanded diagnostic scope as well as the limitations of transthoracic echocardiography (TTE) - lack of acoustic windows, patient positioning, and competing clinical interests (eg, the need to perform chest compressions). The objectives of this scoping review were to determine the indications, clinical impact, and complications of ccTEE.

METHODS

MEDLINE, EMBASE, Cochrane, and six major conferences were searched without a time or language restriction on March 31^st, 2021. Studies were included if they assessed TEE performed for adult critically ill patients by intensivists, emergency physicians, or anesthesiologists. Intraoperative or post-cardiac surgical TEE studies were excluded. Study demographics, indication for TEE, main results, and complications were extracted in duplicate.

RESULTS

Of the 4403 abstracts screened, 289 studies underwent full-text review, with 108 studies (6739 patients) included. Most studies were retrospective (66%), performed in academic centers (84%), in the intensive care unit (73%), and were observational (55%). The most common indications for ccTEE were hemodynamic instability, trauma, cardiac arrest, respiratory failure, and procedural guidance. Across multiple indications, ccTEE was reported to change the diagnosis in 52% to 78% of patients and change management in 32% to79% patients. During cardiac arrest, ccTEE identified the cause of arrest in 25% to 35% of cases. Complications of ccTEE included two cases of significant gastrointestinal bleeding requiring intervention, but no other major complications (death or esophageal perforation) reported.

CONCLUSIONS

The use of ccTEE has been described for the diagnosis and management of a broad range of clinical problems. Overall, ccTEE was commonly reported to offer additional diagnostic yield beyond TTE with a low observed complication rate. Additional high quality ccTEE studies will permit stronger conclusions and a more precise understanding of the trends observed in this scoping review.

Carotid Doppler ultrasound for non-invasive haemodynamic monitoring: a narrative review

Objective.Accurate haemodynamic monitoring is the cornerstone in the management of critically ill patients. It guides the optimization of tissue and organ perfusion in order to prevent multiple organ failure. In the past decades, carotid Doppler ultrasound (CDU) has been explored as a non-invasive alternative for long-established invasive haemodynamic monitoring techniques. Considering the large heterogeneity in reported studies, we conducted a review of the literature to clarify the current status of CDU as a haemodynamic monitoring tool.Approach.In this article, firstly an overview is given of the equipment and workflow required to perform a CDU exam in clinical practice, the limitations and technical challenges potentially faced by the CDU sonographer, and the cerebrovascular mechanisms that may influence CDU measurement outcomes. The following chapter describes alternative techniques for non-invasive haemodynamic monitoring, detailing advantages and limitations compared to CDU. Next, a comprehensive review of the literature regarding the use of CDU for haemodynamic monitoring is presented. Furthermore, feasibility aspects, training requirements and technical developments of CDU are addressed.Main results.Based on the outcomes of these studies, we assess the applicability of CDU-derived parameters within three clinical domains (cardiac output, volume status, and fluid responsiveness), and amongst different patient groups. Finally, recommendations are provided to improve the quality and standardization of future research and clinical practice in this field.Significance.Although CDU is not yet interchangeable with invasive 'gold standard' cardiac output monitoring, the present work shows that certain CDU-derived parameters prove promising in the context of functional haemodynamic monitoring.

Protocolised reduction of non-resuscitation fluids versus usual care in patients with septic shock (REDUSE): a protocol for a multicentre feasibility trial

INTRODUCTION

Administration of large volumes of fluids is associated with poor outcome in septic shock. Recent data suggest that non-resuscitation fluids are the major source of fluids in the intensive care unit (ICU) patients suffering from septic shock. The present trial is designed to test the hypothesis that a protocol targeting this source of fluids can reduce fluid administration compared with usual care.

METHODS AND ANALYSIS

The design will be a multicentre, randomised, feasibility trial. Adult patients admitted to ICUs with septic shock will be randomised within 12 hours of admission to receive non-resuscitation fluids either according to a restrictive protocol or to receive usual care. The healthcare providers involved in the care of participants will not be blinded. The participants, outcome assessors at the 6-month follow-up and statisticians will be blinded. Primary outcome will be litres of fluids administered within 3 days of randomisation. Secondary outcomes will be proportion of randomised participants with outcome data on all-cause mortality; days alive and free of mechanical ventilation within 90 days of inclusion; any acute kidney injury and ischaemic events in the ICU (cerebral, cardiac, intestinal or limb ischaemia); proportion of surviving randomised patients who were assessed by European Quality of Life 5-Dimensions 5-Level questionnaire and Montreal Cognitive Assessment; proportion of all eligible patients who were randomised and proportion of participants experiencing at least one protocol violation.

ETHICS AND DISSEMINATION

Ethics approval has been obtained in Sweden. Results of the primary and secondary outcomes will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05249088.