Distinct hemodynamic patterns of septic shock at presentation to pediatric intensive care

Susceptibility to childhood sepsis, contemporary management, and future directions

Sepsis disproportionally affects children across all health-care settings and is one of the leading causes of morbidity and mortality in neonatal and paediatric age groups. As shown in the first paper in this Series, the age-specific incidence of sepsis is highest during the first years of life, before approaching adult incidence rates during adolescence. In the second paper in this Series, we focus on the unique susceptibility of paediatric patients to sepsis and how the underlying dysregulated host response relates to developmental aspects of children's immune system, genetic, perinatal, and environmental factors, and comorbidities and socioeconomic determinants of health, which often differ between children and adults. State-of-the-art clinical management of paediatric sepsis is organised around three treatment pillars-diagnosis, early resuscitation, and titration of advanced care-and we examine available treatment guidelines and the limitations of their supporting evidence. Serious evidence gaps remain in key areas of paediatric sepsis care, especially surrounding recognition, common interventions, and survivor support, and to this end we offer a research roadmap for the next decade that could accelerate targeted diagnostics and personalised use of immunomodulation. However, improving outcomes for children with sepsis relies fundamentally on systematic quality improvement in both recognition and treatment, which is the theme of the third paper in this Series. Digital health, as shown in the fourth and final paper of this Series, holds promising potential in breaking down the barriers that hinder progress in paediatric sepsis care and, ultimately, global child health.

Central Venous Oxygen Saturation in Children With Cancer

OBJECTIVE

Central venous saturation (ScvO2) can guide resuscitation of children with septic shock. The normal range of ScvO2 is typically considered as 0.70-0.80, but has not been established in children with cancer. Children with cancer are particularly prone to develop sepsis due to their immunosuppressive therapy, and usually have a permanent central venous catheter, making ScvO2 readily available. We aimed to investigate normal values of ScvO2 in clinically stable children with cancer, and the association between ScvO2, hemoglobin, and lactate.

METHODS

We conducted a prospective clinical study at the outpatient clinic of a tertiary pediatric hematology/oncology unit. Blood samples were collected from stable children aged 0-17.9 years who were treated for cancer between January 1 and November 30, 2019, during their routine outpatient clinic visits.

RESULTS

A total of 183 blood samples were collected from 68 patients (24 girls and 44 boys). The predicted mean level of ScvO2 with a 95% confidence interval was 0.67 (0.56-0.78). The ScvO2 value was below the expected lower normal limit of 0.70 in 126 (69%) of the samples and in 48 patients (71%) at least once. ScvO2 was significantly associated with hemoglobin (β1 = 0.012 per g/L hemoglobin, P < 0.001), but not with age, sex, underlying diagnosis, or lactate.

CONCLUSIONS

The study revealed that a substantial portion of clinically stable childhood cancer patients exhibited ScvO2 levels below the typical reference value of 0.70, suggesting that these children may have inherently lower baseline ScvO2 levels. This should be kept in mind when evaluating children with cancer for septic shock, emphasizing the importance of tailored assessments in this population. Further understanding of baseline ScvO2 abnormalities may be helpful if ScvO2 is used to guide resuscitation.

Management Changes After Echocardiography Are Associated With Improved Outcomes in Critically Ill Children

OBJECTIVES

To evaluate management changes and outcomes in critically ill children after formal echocardiography.

DESIGN

Retrospective cohort study between January 1, 2011, and December 31, 2020.

SETTING

Tertiary care children's hospital.

PATIENTS

Patients from 1 to 18 years who had formal echocardiography within 72 hours of ICU admission and who were intubated and on vasoactive infusions at the time of the study. Patients were stratified into two cardiac function groups: 1) near-normal cardiac function and 2) depressed cardiac function.

METHODS

Clinical variables were abstracted from the electronic medical record and placed in time sequence relative to echocardiography. Vasoactive and fluid management strategies in place before echocardiography were associated with markers of tissue perfusion and volume overload. Management changes after echocardiography were characterized and associated with outcomes.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among patients eventually found to have depressed cardiac function, the use of vasoconstrictors was associated with worse lactate clearance and oxygen extraction ratio. Use of vasoconstrictors in this cohort was also associated with a more liberal fluid management strategy, evidence of increased lung water, and a worse Sp o2 /F io2 . An echocardiogram demonstrated depressed cardiac function was likely to be followed by management changes that favored inotropes and more conservative fluid administration. Patients with depressed cardiac function who were switched to inotropes were more likely to be extubated and to wean off vasoactive support compared with those patients who remained on vasoconstrictors.

CONCLUSIONS

Among patients with depressed cardiac function, alterations in management strategy after echocardiography are associated with shortened duration of intensive care interventions.

Vascular Reactivity Index as an Effective Predictor of Mortality in Patients With Septic Shock: A Retrospective Study

BACKGROUND

Sepsis is a serious complication that occurs after trauma, burns, and infections, and it is an important cause of death in intensive care unit (ICU) patients. Despite many new measures being proposed for sepsis treatment, its mortality rate remains high; sepsis has become a serious threat to human health, and there is an urgent need to carry out in-depth clinical research related to sepsis. In recent years, it has been found that septic shock-induced vasoplegia is a result of vascular hyporesponsiveness to vasopressors. Therefore, this study intended to establish an objective formula related to vasoplegia that can be used to assess the prognosis of patients and guide clinical treatment.

MATERIALS AND METHODS

A retrospective cohort study was conducted using data from 106 septic shock patients admitted to the ICU of Jining No. 1 People's Hospital from January 2020 to December 2022. The patients were divided into mortality and survival groups based on 28-day survival, and hemodynamics were monitored by the pulse index continuous cardiac output system. The dose and duration of vasopressors, major hemodynamic parameters, lactic acid (Lac) levels, and Sequential Organ Failure Assessment scores were recorded within 48 h of hospital admission. Multifactorial logistic regression was used to analyze the independent risk factors affecting the prognosis of patients, and the predictive value of the vascular response index (VRI) was analyzed by the receiver operating characteristic (ROC) curve.

RESULTS

The differences between the survival and mortality groups in terms of age, sex ratio, body weight, ICU length of stay, distribution of infection sites, underlying disease conditions, baseline Lac levels, and some hemodynamic parameters were not statistically significant (P > .05). The results of multifactorial logistic regression showed that the admission Acute Physiology and Chronic Health Evaluation II score, Lac level at 24 h of treatment, maximal vasoactive inotropic score at 24 h (VISmax24), maximal vasoactive inotropic score at 48 h (VISmax48), and VRI were independent risk factors affecting 28-day mortality. Within 48 h of receiving vasopressor therapy, the VRI was lower in the mortality group than in the survival group. The area under the ROC curve for the VRI was 0.86, and the best cutoff value of the VRI for predicting 28-day mortality was 32.50 (YI = 0.80), with a sensitivity of 0.90, a specificity of 0.90, and a better prediction of mortality than the other indicators.

CONCLUSIONS

The VRI is a good predictor of mortality in patients with septic shock, and a lower VRI indicates more severe vasoplegia, poorer prognosis, and higher mortality in patients with septic shock.

Resuscitation With Early Adrenaline Infusion for Children With Septic Shock: A Randomized Pilot Trial

OBJECTIVES

In children with septic shock, guidelines recommend resuscitation with 40-60 mL/kg of fluid boluses, yet there is a lack of evidence to support this practice. We aimed to determine the feasibility of a randomized trial comparing early adrenaline infusion with standard fluid resuscitation in children with septic shock.

DESIGN

Open-label parallel randomized controlled, multicenter pilot study. The primary end point was feasibility; the exploratory clinical endpoint was survival free of organ dysfunction by 28 days.

SETTING

Four pediatric Emergency Departments in Queensland, Australia.

PATIENTS

Children between 28 days and 18 years old with septic shock.

INTERVENTIONS

Patients were assigned 1:1 to receive a continuous adrenaline infusion after 20 mL/kg fluid bolus resuscitation (n = 17), or standard care fluid resuscitation defined as delivery of 40 to 60 mL/kg fluid bolus resuscitation prior to inotrope commencement (n = 23).

MEASUREMENTS AND MAIN RESULTS

Forty of 58 eligible patients (69%) were consented with a median age of 3.7 years (interquartile range [IQR], 0.9-12.1 yr). The median time from randomization to inotropes was 16 minutes (IQR, 12-26 min) in the intervention group, and 49 minutes (IQR, 29-63 min) in the standard care group. The median amount of fluid delivered during the first 24 hours was 0 mL/kg (IQR, 0-10.0 mL/kg) in the intervention group, and 20.0 mL/kg (14.6-28.6 mL/kg) in the standard group (difference, -20.0; 95% CI, -28.0 to -12.0). The number of days alive and free of organ dysfunction did not differ between the intervention and standard care groups, with a median of 27 days (IQR, 26-27 d) versus 26 days (IQR, 25-27 d). There were no adverse events reported associated with the intervention.

CONCLUSIONS

In children with septic shock, a protocol comparing early administration of adrenaline versus standard care achieved separation between the study arms in relation to inotrope and fluid bolus use.

Pediatric Sepsis Diagnosis, Management, and Sub-phenotypes

Sepsis and septic shock are major causes of morbidity, mortality, and health care costs for children worldwide, including >3 million deaths annually and, among survivors, risk for new or worsening functional impairments, including reduced quality of life, new respiratory, nutritional, or technological assistance, and recurrent severe infections. Advances in understanding sepsis pathophysiology highlight a need to update the definition and diagnostic criteria for pediatric sepsis and septic shock, whereas new data support an increasing role for automated screening algorithms and biomarker combinations to assist earlier recognition. Once sepsis or septic shock is suspected, attention to prompt initiation of broad-spectrum empiric antimicrobial therapy, fluid resuscitation, and vasoactive medications remain key components to initial management with several new and ongoing studies offering new insights into how to optimize this approach. Ultimately, a key goal is for screening to encompass as many children as possible at risk for sepsis and trigger early treatment without increasing unnecessary broad-spectrum antibiotics and preventable hospitalizations. Although the role for adjunctive treatment with corticosteroids and other metabolic therapies remains incompletely defined, ongoing studies will soon offer updated guidance for optimal use. Finally, we are increasingly moving toward an era in which precision therapeutics will bring novel strategies to improve outcomes, especially for the subset of children with sepsis-induced multiple organ dysfunction syndrome and sepsis subphenotypes for whom antibiotics, fluid, vasoactive medications, and supportive care remain insufficient.

Cardiac output monitoring in children: a review

Cardiac output monitoring enables physiology-directed management of critically ill children and aids in the early detection of clinical deterioration. Multiple invasive techniques have been developed and have demonstrated ability to improve clinical outcomes. However, all require invasive arterial or venous catheters, with associated risks of infection, thrombosis and vascular injury. Non-invasive monitoring of cardiac output and fluid responsiveness in infants and children is an active area of interest and several proven techniques are available. Novel non-invasive cardiac output monitors offer a promising alternative to echocardiography and have proven their ability to influence clinical practice. Assessment of perfusion remains a challenge; however, technologies such as near-infrared spectroscopy and photoplethysmography may prove valuable clinical adjuncts in the future.

Beyond Conventional Hemodynamic Monitoring-Monitoring to Improve Our Understanding of Disease Process and Interventions

Monitoring the hemodynamic state of patients is a hallmark of any intensive care environment. However, no single monitoring strategy can provide all the necessary data to paint the entire picture of the state of a patient; each monitor has strengths and weaknesses, advantages, and limitations. We review the currently available hemodynamic monitors used in pediatric critical care units using a clinical scenario. This provides the reader with a construct to understand the progression from basic to more advanced monitoring modalities and how they serve to inform the practitioner at the bedside.

Sepsis in the Pediatric Cardiac Intensive Care Unit: An Updated Review

Sepsis remains among the most common causes of mortality in children with congenital heart disease (CHD). Extensive literature is available regarding managing sepsis in pediatric patients without CHD. Because the cardiovascular pathophysiology of children with CHD differs entirely from their typical peers, the available diagnosis and management recommendations for sepsis cannot be implemented directly in children with CHD. This review discusses the risk factors, etiopathogenesis, available diagnostic tools, resuscitation protocols, and anesthetic management of pediatric patients suffering from various congenital cardiac lesions. Further research should focus on establishing a standard guideline for managing children with CHD with sepsis and septic shock admitted to the intensive care unit.

Vascular Reactivity Index and PELOD-2 as a mortality predictor in paediatric septic shock: a single-centre retrospective study

BACKGROUND

The mortality rate for children with septic shock is stil quite high in low-income and middle-income countries (31.7%). One of the most widely used scoring systems to assess mortality in sepsis or septic shock is Paediatric Logistic Organ Dysfunction 2 (PELOD-2). However, it requires various laboratory evaluations. A non-invasive, fast and easy method is needed to assess the mortality of children with septic shock at an early stage. Therefore, this study aims to evaluate the ability of Vascular Reactivity Index (VRI) compared with PELOD-2 score as a predictor of mortality in children with septic shock based on vascular response to vasoactive agents.

METHODS

A retrospective cohort study was conducted using data from children aged 1 month to 18 years with septic shock treated in the ER and paediatric intensive care unit (PICU) of the tertiary hospital from 2017 to 2021. The serial haemodynamic data were analysed including Systemic Vascular Resistant Index (SVRI) and the cardiac index from ultrasound cardiac output monitoring device was recorded in the first and sixth hours after the diagnosis of septic shock. The VRI was determined by dividing SVRI/Vasoactive Inotropic Score (ie, accumulated doses of dopamine, dobutamine, epinephrine, milrinone, vasopressin and norepinephrine). The receiver operating curve was used to calculate the area under the curve (AUC), sensitivity and specificity of each cut-off point.

RESULTS

A total of 68 subjects fulfilled the inclusion and exclusion criteria, the median age was 54 months with a range of 2-204 months and the mortality rate was 47%. The majority of the patients who died were found in the high cardiac index and low SVRI group (17.6%). Moreover, the optimum cut-off point of VRI was obtained to predict mortality in septic shock of 32.1, with 87.5% sensitivity and 88.9% specificity. The AUC for predicting death using VRI was 95% (95% CI 90% to 100%, p<0.001) and PELOD-2 92.6% (95% CI 96.4% to 98.8%, p<0.001).

CONCLUSION

The VRI <32.1 may potentially be used to predict mortality in children with septic shock and its predictive ability is as good as PELOD-2. The assessment of VRI is faster and easier than PELOD-2.

Measurement of Cardiac Output Using an Ultrasonic Cardiac Output Monitor (USCOM) in Patients with Single-Ventricle Physiology

We evaluate the validity of cardiac index (CI) measurements utilizing the Ultrasonic Cardiac Output Monitor (USCOM), a non-invasive Doppler ultrasound device, by comparing measurements to cardiac catheterization-derived CI measurements in patients with single-ventricle physiology. USCOM measurements were repeated three times for each patient at the beginning of a cardiac catheterization procedure for twenty-six patients undergoing elective pre-Glenn or pre-Fontan catheterization. CI was measured by USCOM and was calculated from cardiac catheterization data using Fick's method. Bland-Altman analysis for CI showed bias of 0.95 L/min/m² with the 95% limits of agreement of - 1.85 and 3.75. Pearson's correlation coefficient was 0.89 (p < 0.001) indicating a strong positive relationship between USCOM and cardiac catheterization CI measurements. When excluding two patients with significant dilation of the neo-aortic valve (z-score >  + 5), the bias improved to 0.66 L/min/m² with the 95% limits of agreement of - 1.38 and 2.70. Percent error of limits of agreement was 34%. There was excellent intra-operator reproducibility of USCOM CI measurements with an intra-class coefficient of 0.96. We demonstrate the use of USCOM to measure CI in patients with single-ventricle physiology for the first time, showing acceptable agreement of the CI measurements between USCOM and cardiac catheterization with a high intra-operator reproducibility.

Integrated insights into the mechanisms underlying sepsis-induced myocardial depression using a quantitative global proteomic analysis

Sepsis-induced myocardial depression is common among patients in the intensive care unit; however, the exact mechanisms underlying this condition remain unclear. We investigated differences in the expression of specific proteins and determined the potential functions of the proteins in a rat model of lipopolysaccharide-induced septic shock. Left ventricular tissue was excised from 16 rats (sepsis group, 8; control group, 8) and analysed. Quantitative analysis of the global proteome was performed using 4D label-free technique. Bioinformatic analyses were conducted based on differentially expressed (DE) proteins. Parallel reaction monitoring (PRM) validation for selected proteins and western blotting for selected global protein modifications in heart tissues were also performed. As a result, out of 3653 proteins identified, 108 were expressed differentially between the two groups. The bioinformatic analyses revealed that DE proteins play important roles in metabolism- and immune-related pathways. PRM results supported the plausibility and reliability of the proteomics data. Modification of heart tissue acetyllysine, succinyllysine, 2-hydroxyisobutyryllysine, and lactyllysine revealed clear differences between the two groups, indicating the effects of protein modification. Our study suggested that expression patterns of global proteins in heart tissue were different between the two groups. These results provide new valuable information on the possible mechanisms underlying sepsis-induced myocardial depression. SIGNIFICANCE: The expression patterns of global proteins in the heart tissues of patients with sepsis and control groups remain unknown. In this study, we used the 4D label-free proteomics technique to compare differentially expressed (DE) proteins between the sepsis and control groups. We identified 3653 proteins, 108 of which were expressed differentially between the sepsis and control groups. Further bioinformatic analyses revealed that DE proteins play critical roles in metabolism- and immune-related processes and pathways. Interestingly, modification of heart tissue acetyllysine, succinyllysine, 2-hydroxyisobutyryllysine, and lactyllysine revealed clear differences between the sepsis and control groups. The findings of this study improve our understanding of the basic molecular mechanisms underlying sepsis-induced myocardial depression.

Characteristics of hemodynamic parameters after fluid resuscitation and vasoactive drugs administration in pediatric shock: A prospective observational study

Background

Prior studies have shown that septic shock survivors had a normal cardiac index (CI) and systemic vascular resistance index (SVRI). However, this feature seems to be questionable in other-caused shock, since several factors are associated with the hemodynamic profile. This study aims to describe hemodynamic profiles (preload, inotropy, afterload, stroke volume, and cardiac output) after fluid resuscitation and vasoactive therapy in children with shock.

Methods

Children aged 1 month to 18 years old with shock conditions were included in this study. Fluid resuscitation was administered following the American College of Critical Care Medicine (ACCM) protocol. Hemodynamic profiles were assessed at 1 and 6 h from the start of fluid resuscitation. Grouping of the subjects was determined by the USCOM examination in 1st hour until the end of the study and we divided into 3 groups.

Results

At 1 h, group 1 (low CI) was 14% (CI:2.5[1.2–3.2]L/min/m²), group 2 (normal CI) was 66% (CI:4.2[3.4–5.8]L/min/m²), and group 3 (high CI) was 20% (CI:7.1[6.1–9.4]L/min/m²). SVRI was higher in groups 1 and 2 compared to group 3 (p < 0.05). Group 1 and 2 revealed fluid-refractory shock (SVV:25[12–34]% and 29(13–58)%, respectively), lower Smith-Madigan Inotropy Index (SMII) and higher Potential to Kinetic Ratio (PKR) compared to group 3 (p < 0.05). Group 3 revealed fluid-responsive shock (Stroke Volume Variation (SVV):32[18–158]%), higher SMII and lower PKR. At 6th hour, CI in all groups were normal (group 1:3.5[1.2–7.5]; group 2:4.0[1.7–6.1]; group 3:6.0[3.1–6.2]). However, 71.4% and 54.5% of subjects in groups 1 and 2, respectively, still revealed low inotropy. Group 3 revealed a significant increase in SVRI and PKR (p < 0.01).

Conclusions

Most pediatric shock patients were hypodynamic. Even when the CI was normal, the preload, inotropy, and afterload may still be abnormal. It represented the inotropy as a key to hemodynamic.

•

Describe the macrocirculation parameter (preload, inotropy, afterload) in children with shock.

•

Most pediatric shock tend to be hypodynamic.

•

Fluid and vasoactive agent therapy should be guided by combination of the hemodynamic parameters.

Use of Inotropics by Peripheral Vascular Line in the First Hour of Treatment of Pediatric Septic Shock: Experience at an Emergency Department

OBJECTIVE

Mortality in pediatric septic shock remains unacceptably high. Delays in vasopressor administration have been associated with an increased risk of mortality. Current treatment guidelines suggest the use of a peripheral vascular line (PVL) for inotropic administration in fluid-refractory septic shock when a central vascular line is not already in place. The aim of this study was to report local adverse effects associated with inotropic drug administration through a PVL at a pediatric emergency department setting in the first hour of treatment of septic shock.

METHODS

A prospective, descriptive, observational cohort study of patients with septic shock requiring PVL inotropic administration was conducted at the pediatric emergency department of a tertiary care pediatric hospital. For the infusion and postplacement care of the PVL for vasoactive drugs, an institutional nursing protocol was used.

RESULTS

We included 49 patients; 51% had an underlying disease. Eighty-four percent of the children included had a clinical "cold shock." The most frequently used vasoactive drug was epinephrine (72%). One patient presented with local complications.

CONCLUSIONS

At our center, infusion of vasoactive drugs through a PVL was shown to be safe and allowed for adherence to the current guidelines for pediatric septic shock.

Latin American Consensus on the Management of Sepsis in Children: Sociedad Latinoamericana de Cuidados Intensivos Pediátricos [Latin American Pediatric Intensive Care Society] (SLACIP) Task Force: Executive Summary

OBJECTIVE

The aim of this study was to develop evidence-based recommendations for the diagnosis and treatment of sepsis in children in low- and middle-income countries (LMICs), more specifically in Latin America. Design: A panel was formed consisting of 27 experts with experience in the treatment of pediatric sepsis and two methodologists working in Latin American countries. The experts were organized into 10 nominal groups, each coordinated by a member. Methods: A formal consensus was formed based on the modified Delphi method, combining the opinions of nominal groups of experts with the interpretation of available scientific evidence, in a systematic process of consolidating a body of recommendations. The systematic search was performed by a specialized librarian and included specific algorithms for the Cochrane Specialized Register, PubMed, Lilacs, and Scopus, as well as for OpenGrey databases for grey literature. The GRADEpro GDT guide was used to classify each of the selected articles. Special emphasis was placed on search engines that included original research conducted in LMICs. Studies in English, Spanish, and Portuguese were covered. Through virtual meetings held between February 2020 and February 2021, the entire group of experts reviewed the recommendations and suggestions. Result: At the end of the 12 months of work, the consensus provided 62 recommendations for the diagnosis and treatment of pediatric sepsis in LMICs. Overall, 60 were strong recommendations, although 56 of these had a low level of evidence. Conclusions: These are the first consensus recommendations for the diagnosis and management of pediatric sepsis focused on LMICs, more specifically in Latin American countries. The consensus shows that, in these regions, where the burden of pediatric sepsis is greater than in high-income countries, there is little high-level evidence. Despite the limitations, this consensus is an important step forward for the diagnosis and treatment of pediatric sepsis in Latin America.

Role of non-coding RNAs as biomarkers of deleterious cardiovascular effects in sepsis

The mechanisms occurring during sepsis that produce an increased risk of cardiovascular (CV) disease (CVD) are poorly understood. Even less information exists regarding CV dysfunction as a complication of sepsis, particularly for sepsis-induced cardiomyopathy. However, recent research has demonstrated that non-coding RNAs, including microRNAs, long non-coding RNAs, and circular RNAs, play a crucial role in genetic reprogramming, gene regulation, and inflammation during the development of CVD. Here we describe experimental findings showing the importance of non-coding RNAs mediating relevant mechanisms underlying CV dysfunction after sepsis, so contributing to sepsis-induced cardiomyopathy. Importantly, non-coding RNAs are critical novel regulators of CVD risk factors. Thus, they are potential candidates to improve diagnostics and prognosis of sepsis-induced cardiomyopathy and other CVD events occurring after sepsis and set the basis to design novel therapeutic strategies.

Ultrasonic cardiac output monitor provides effective non-invasive bedside measurements of neonatal cardiac output

This study determined the accuracy and validity for the haemodynamic parameters of haemodynamically stable neonates after postnatal circulatory adaptation using the ultrasonic cardiac output monitor (USCOM) in comparison with echocardiography. We conducted a prospective, observational study of neonates born at 23-41 weeks of gestation. They all underwent both echocardiography and USCOM assessments for comparison purposes. The 127 neonates were examined at the median of postmenstrual age of 35 weeks and there was a very high correlation between the cardiac output measurements provided by both methods. The mean difference in cardiac output was - 12 ± 25 ml/kg/min, with percentage error of 8.3 ± 6.9%. A larger bias was observed in cases with higher left ventricular output. Bland-Altman analysis confirmed no significant bias, with acceptable limits of agreement between these two methods. There was a very good correlation between the USCOM and echocardiographic methods when we used them to measure cardiac output in neonates.

Comparative transcriptome analysis of transcripts of uncertain coding potential in septic myocardial depression

BACKGROUND

Septic shock with myocardial depression is very common in intensive care units. However, the exact molecular mechanisms underlying sepsis-induced myocardial depression remain unclear. Whether the profiles of transcripts of uncertain coding potential (TUCPs) differ between patients with and without myocardial depression is also unknown. Our study aimed to find expression differences between groups of TUCPs and determine their potential functions in a preclinical model.

METHODS

We generated rat models of hypodynamic septic shock induced by lipopolysaccharide. A total of 12 rats were established and left ventricular tissue from each was collected. We performed RNA-seq to identify TUCPs in each sample. Transcripts with an corrected P value of < 0.05 were defined as differentially expressed (DE). We also performed GO terms and KEGG analysis to identify the potential functions of DE TUCPs.

RESULTS

A total of 4,851 TUCPs were identified in heart samples, 85 of which were expressed differently between the sepsis and control groups. Further bioinformatic analyses suggested that TUCPs play important roles in myocardial contraction, energy regulation, and metabolic processes, and are also involved in the regulation of several pathways.

CONCLUSION

Our results demonstrate that TUCPs both participate in and mediate the pathological process of myocardial depression. Our study improves the understanding of the basic molecular mechanisms underlying myocardial depression from a novel perspective.

Electrocardiometry for Hemodynamic Categorization and Assessment of Fluid Responsiveness in Pediatric Septic Shock: A Pilot Observational Study

Aim

To evaluate the utility of noninvasive electrocardiometry (ICON®) for hemodynamic categorization and assessment of fluid responsiveness in pediatric septic shock.

Materials and methods

Pilot prospective observational study in a 12-bedded tertiary pediatric intensive care unit (PICU) in children aged between 2 months and 16 years with unresolved septic shock after a 20 mL/kg fluid bolus. Those with cardiac index (CI) <3.3 L/min/m² and systemic vascular resistance index (SVRI) >1600 dyn sec/cm⁵/m² were classified as vasoconstrictive shock–electrocardiometry (VCEC) and those with CI >5.5 L/min/m² and SVRI <1000 dyn sec/cm⁵/m² as vasodilated shock–electrocardiometry (VDEC). Fluid responsiveness was defined as a 10% increase in CI with a 20 mL/kg fluid bolus. Sepsis-induced myocardial dysfunction (SMD) was diagnosed on echocardiography. Outcomes studied included clinical shock resolution, length of PICU stay, and mortality.

Results

Thirty children were enrolled over 6 months with a median (interquartile range) age and pediatric risk of mortality (PRISM) III score of 87(21,108) months and 6.75(1.5,8.25), respectively; 14(46.6%) were boys and 4(13.3%) died. Clinically, 19(63.3%) children had cold shock and 11(36.7%) had warm shock; however, 16(53.3%) children had VDEC (including five with clinical cold shock) and 14(46.7%) had VCEC using electrocardiometry. Fluid responsiveness was seen in 16(53.3%) children, 10 in the VCEC group and 6 in the VDEC group. In the VCEC group, the responders had a significant rise in CI and a fall in SVRI, while the responders in the VDEC group had a significant rise in CI and SVRI. Fluid responders, compared to nonresponders, had a significantly higher stroke volume variation (SVV) before fluid bolus (24.1 ± 5.2% vs. 18.2 ± 3.5%, p < 0.001) and a higher reduction in SVV after fluid bolus (10.0 ± 2.8% vs. 6.0 ± 4.5%, p = 0.006), higher lactate clearance (p = 0.03) and lower vasoactive-inotropic score (p = 0.04) at 6 hours, higher percentage of clinical shock resolution at 6 (p = 0.01) and 12 hours (p = 0.01), and lesser mortality (p = 0.002). Five (16.6%) children with VCEC had SMD and were less fluid responsive (p = 0.04) with higher mortality (p = 0.01) compared to those without SMD.

Conclusions and clinical significance

Continuous, noninvasive hemodynamic monitoring using electrocardiometry permits hemodynamic categorization and assessment of fluid responsiveness in pediatric septic shock. This may provide real-time guidance for optimal interventions, and thus, improve the outcomes.

How to cite this article

Rao SS, Reddy M, Lalitha AV, Ghosh S. Electrocardiometry for Hemodynamic Categorization and Assessment of Fluid Responsiveness in Pediatric Septic Shock: A Pilot Observational Study. Indian J Crit Care Med 2021;25(2):185–192.

Early Resuscitation in Paediatric Sepsis Using Inotropes - A Randomised Controlled Pilot Study in the Emergency Department (RESPOND ED): Study Protocol and Analysis Plan

Introduction: Septic shock in children still carries substantial mortality and morbidity. While resuscitation with 40-60 mL/kg intravenous fluid boluses remains a cornerstone of initial resuscitation, an increasing body of evidence indicates potential for harm related to high volume fluid administration. We hypothesize that a protocol on early use of inotropes in children with septic shock is feasible and will lead to less fluid bolus use compared to standard fluid resuscitation. Here, we describe the protocol of the Early Resuscitation in Paediatric Sepsis Using Inotropes - A Randomised Controlled Pilot Study in the Emergency Department (RESPOND ED). Methods and analysis: The RESPOND ED study is an open label randomised controlled, two arm, multicentre pilot study conducted at four specialised paediatric Emergency Departments. Forty children aged between 28 days and 18 years treated for presumed septic shock will be randomized in a 1:1 ratio to early inotropes vs. standard fluid resuscitation. Early inotrope treatment is defined as the commencement of a continuous intravenous adrenaline infusion after 20 mL/kg fluid bolus resuscitation. Standard fluid resuscitation is defined as delivery of 40 to 60 mL/kg fluid bolus resuscitation prior to commencement of inotropes. In addition to feasibility outcomes, survival free of organ dysfunction censored at 28 days will be assessed as the main clinical outcome. The study cohort will be followed up at 28 days, and at 6 months post enrolment to assess quality of life and functional status. Biobanking nested in the study cohort will be performed to enable ancillary biomarker studies. Ethics and dissemination: The trial has ethical clearance (Children's Health Queensland, Brisbane, HREC/18/QCHQ/49168) and is registered in the Australian New Zealand Clinical Trials Registry (ACTRN12619000828123). Enrolment commenced on July 21st, 2019. The primary manuscript will be submitted for publication in a peer-reviewed journal. Trial Registration: Australian and New Zealand Clinical Trials Registry, ACTRN12619000828123.

Clinical Signs to Categorize Shock and Target Vasoactive Medications in Warm Versus Cold Pediatric Septic Shock

OBJECTIVES

Determine level of agreement among clinical signs of shock type, identify which signs clinicians prioritize to determine shock type and select vasoactive medications, and test the association of shock type-vasoactive mismatch with prolonged organ dysfunction or death (complicated course).

DESIGN

Retrospective observational study.

SETTING

Single large academic PICU.

PATIENTS

Patients less than 18 years treated on a critical care sepsis pathway between 2012 and 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Agreement among clinical signs (extremity temperature, capillary refill, pulse strength, pulse pressure, and diastolic blood pressure) was measured using Fleiss and Cohen's κ. Association of clinical signs with shock type and shock type-vasoactive mismatch (e.g., cold shock treated with vasopressor rather than inotrope) with complicated course was determined using multivariable logistic regression. Of 469 patients, clinicians determined 307 (65%) had warm and 162 (35%) had cold shock. Agreement across all clinical signs was low (κ, 0.25; 95% CI, 0.20-0.30), although agreement between extremity temperature, capillary refill, and pulse strength was better than with pulse pressure and diastolic blood pressure. Only extremity temperature (adjusted odds ratio, 26.6; 95% CI, 15.5-45.8), capillary refill (adjusted odds ratio, 15.7; 95% CI, 7.9-31.3), and pulse strength (adjusted odds ratio, 21.3; 95% CI, 8.6-52.7) were associated with clinician-documented shock type. Of the 86 patients initiated on vasoactive medications during the pathway, shock type was discordant from vasoactive medication (κ, 0.14; 95% CI, -0.03 to 0.31) and shock type-vasoactive mismatch was not associated with complicated course (adjusted odds ratio, 0.3; 95% CI, 0.1-1.02).

CONCLUSIONS

Agreement was low among common clinical signs used to characterize shock type, with clinicians prioritizing extremity temperature, capillary refill, and pulse strength. Although clinician-assigned shock type was often discordant with vasoactive choice, shock type-vasoactive mismatch was not associated with complicated course. Categorizing shock based on clinical signs should be done cautiously.

Ultrasound cardiac output monitoring in mechanically ventilated children

AIM

To non-invasively identify the hemodynamic changes in critically ill children during the first 48 h following initiation of mechanical ventilation by the ultrasound cardiac output monitor (USCOM) method and compare the data in children with pulmonary and non-pulmonary pathology.

MATERIALS AND METHODS

This was a prospective observational study to evaluate the influence of mechanical ventilation on hemodynamic changes and to describe hemodynamic profiles of mechanically ventilated children. A total of 56 children with respiratory failure were included in the present study. Ventilated patients are divided into two groups. Group A (n=36) includes patients with pulmonary pathology. Group B (n=20) consists of patients with extra pulmonary etiology of respiratory failure. Hemodynamic parameters (cardiac index and systemic vascular resistance index) were evaluated using ultrasound cardiac output monitoring (USCOM 1A) immediately following initiation of mechanical ventilation and again at 6, 12, and 48 h. Pharmacological circulatory support (inotropes, vasopressors, levosimendan and phosphodiesterase III inhibitors) was individually and continuously modified based on real-time hemodynamic parameters and optimal fluid balance.

RESULTS

No significant differences in hemodynamic profiles were found between Group A and Group B.

CONCLUSION

The protective strategy of mechanical ventilation was not associated with significant differences in hemodynamic profiles between children ventilated for pulmonary and non-pulmonary pathologies.

CLINICAL SIGNIFICANCE

Hemodynamically unstable children ventilated for pulmonary pathology with the protective strategy of mechanical ventilation had a greater requirement for inotropic and combined inotropic and vasoactive circulatory support than children ventilated for non-pulmonary causes of respiratory failure.

Updates on pediatric sepsis

Sepsis, defined as an infection with dysregulated host response leading to life-threatening organ dysfunction, continues to carry a high potential for morbidity and mortality in children. The recognition of sepsis in children in the emergency department (ED) can be challenging, related to the high prevalence of common febrile infections, poor specificity of discriminating features, and the capacity of children to compensate until advanced stages of shock. Sepsis outcomes are strongly dependent on the timeliness of recognition and treatment, which has led to the successful implementation of quality improvement programs, increasing the reliability of sepsis treatment in many US institutions. We review clinical, laboratory, and technical modalities that can be incorporated into ED practice to facilitate the recognition, treatment, and reassessment of children with suspected sepsis. The 2020 updated pediatric sepsis guidelines are reviewed and framed in the context of ED interventions, including guidelines for antibiotic administration, fluid resuscitation, and the use of vasoactive agents. Despite a large body of literature on pediatric sepsis epidemiology in recent years, the evidence base for treatment and management components remains limited, implying an urgent need for large trials in this field. In conclusion, although the burden and impact of pediatric sepsis remains substantial, progress in our understanding of the disease and its management have led to revised guidelines and the available data emphasizes the importance of local quality improvement programs.

Characterization of Circular RNA and microRNA Profiles in Septic Myocardial Depression: a Lipopolysaccharide-Induced Rat Septic Shock Model

Septic shock with heart dysfunction is common in intensive care units. However, the mechanism underlying myocardial depression is still unclear. Whether circular RNA (circRNA) or microRNA (miRNA) profiles differ between patients with and without myocardial depression is unknown. We generated a hypodynamic septic shock model induced by lipopolysaccharide (LPS) in adolescent rats. A total of 12 rats were utilized and heart tissue from each was collected. RNA sequencing was performed on left ventricular tissue. We focused on features of circRNAs and miRNAs, predicting their function by bioinformatic analysis and constructing circRNA-associated and miRNA-associated regulatory networks in heart tissue. We detected 851 circRNAs in heart samples, and 11 showed differential expression. A total of 639 annotated miRNAs and 91 novel miRNAs were explored including 78 showing differential expression between the two groups. We then constructed the most comprehensive circRNA-associated and miRNA-associated networks to explore their regulatory relationship in septic heart tissue, and demonstrated that different networks could potentially participate in and regulate the pathological process of sepsis. Furthermore, gene ontology term enrichment indicated miRNAs, and miRNA-mRNA networks could be associated with regulation and metabolic process, or influence cellular functions. The construction of regulator networks could improve the understanding of the basic molecular mechanisms underlying myocardial depression. It will be important for future investigations to ascertain the biological mechanisms present during the development of sepsis-induced myocardial depression to influence approaches to treatment.

Surviving sepsis campaign international guidelines for the management of septic shock and sepsis-associated organ dysfunction in children

OBJECTIVES

To develop evidence-based recommendations for clinicians caring for children (including infants, school-aged children, and adolescents) with septic shock and other sepsis-associated organ dysfunction.

DESIGN

A panel of 49 international experts, representing 12 international organizations, as well as three methodologists and three public members was convened. Panel members assembled at key international meetings (for those panel members attending the conference), and a stand-alone meeting was held for all panel members in November 2018. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. Teleconferences and electronic-based discussion among the chairs, co-chairs, methodologists, and group heads, as well as within subgroups, served as an integral part of the guideline development process.

METHODS

The panel consisted of six subgroups: recognition and management of infection, hemodynamics and resuscitation, ventilation, endocrine and metabolic therapies, adjunctive therapies, and research priorities. We conducted a systematic review for each Population, Intervention, Control, and Outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak, or as a best practice statement. In addition, "in our practice" statements were included when evidence was inconclusive to issue a recommendation, but the panel felt that some guidance based on practice patterns may be appropriate.

RESULTS

The panel provided 77 statements on the management and resuscitation of children with septic shock and other sepsis-associated organ dysfunction. Overall, six were strong recommendations, 49 were weak recommendations, and nine were best-practice statements. For 13 questions, no recommendations could be made; but, for 10 of these, "in our practice" statements were provided. In addition, 52 research priorities were identified.

CONCLUSIONS

A large cohort of international experts was able to achieve consensus regarding many recommendations for the best care of children with sepsis, acknowledging that most aspects of care had relatively low quality of evidence resulting in the frequent issuance of weak recommendations. Despite this challenge, these recommendations regarding the management of children with septic shock and other sepsis-associated organ dysfunction provide a foundation for consistent care to improve outcomes and inform future research.

Surviving Sepsis Campaign International Guidelines for the Management of Septic Shock and Sepsis-Associated Organ Dysfunction in Children

OBJECTIVES

To develop evidence-based recommendations for clinicians caring for children (including infants, school-aged children, and adolescents) with septic shock and other sepsis-associated organ dysfunction.

DESIGN

A panel of 49 international experts, representing 12 international organizations, as well as three methodologists and three public members was convened. Panel members assembled at key international meetings (for those panel members attending the conference), and a stand-alone meeting was held for all panel members in November 2018. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. Teleconferences and electronic-based discussion among the chairs, co-chairs, methodologists, and group heads, as well as within subgroups, served as an integral part of the guideline development process.

METHODS

The panel consisted of six subgroups: recognition and management of infection, hemodynamics and resuscitation, ventilation, endocrine and metabolic therapies, adjunctive therapies, and research priorities. We conducted a systematic review for each Population, Intervention, Control, and Outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak, or as a best practice statement. In addition, "in our practice" statements were included when evidence was inconclusive to issue a recommendation, but the panel felt that some guidance based on practice patterns may be appropriate.

RESULTS

The panel provided 77 statements on the management and resuscitation of children with septic shock and other sepsis-associated organ dysfunction. Overall, six were strong recommendations, 52 were weak recommendations, and nine were best-practice statements. For 13 questions, no recommendations could be made; but, for 10 of these, "in our practice" statements were provided. In addition, 49 research priorities were identified.

CONCLUSIONS

A large cohort of international experts was able to achieve consensus regarding many recommendations for the best care of children with sepsis, acknowledging that most aspects of care had relatively low quality of evidence resulting in the frequent issuance of weak recommendations. Despite this challenge, these recommendations regarding the management of children with septic shock and other sepsis-associated organ dysfunction provide a foundation for consistent care to improve outcomes and inform future research.

Clinical Update in Pediatric Sepsis: Focus on Children With Pre-Existing Heart Disease

SEPSIS REMAINS one of the most common causes of childhood morbidity, mortality, and higher healthcare costs, with over 75,000 hospital admissions in the United States and an estimated 4 million cases worldwide per year. While standardized criteria to define sepsis are in flux, the general concept of sepsis is a severe infection that results in organ dysfunction. Although sepsis can affect previously healthy children, those with certain pre-existing comorbid conditions, including congenital and acquired heart disease, are at higher risk for both developing sepsis and having a poor outcome after sepsis. Multiple specialists including intensivists, cardiologists, surgeons, and anesthesiologists commonly contribute to the management and outcome of sepsis in children. In this article, the authors examine the evolving epidemiology of pediatric sepsis, including the subset of patients with underlying heart disease; contrast pediatric and adult sepsis; review the latest hemodynamic guidelines for management of pediatric septic shock and their application to children with heart disease; discuss the role of mechanical circulatory support; and review key aspects of anesthetic management for children with sepsis.

Criteria for Critical Care Infants and Children: PICU Admission, Discharge, and Triage Practice Statement and Levels of Care Guidance

OBJECTIVES

To update the American Academy of Pediatrics and Society of Critical Care Medicine's 2004 Guidelines and levels of care for PICU.

DESIGN

A task force was appointed by the American College of Critical Care Medicine to follow a standardized and systematic review of the literature using an evidence-based approach. The 2004 Admission, Discharge and Triage Guidelines served as the starting point, and searches in Medline (Ovid), Embase (Ovid), and PubMed resulted in 329 articles published from 2004 to 2016. Only 21 pediatric studies evaluating outcomes related to pediatric level of care, specialized PICU, patient volume, or personnel. Of these, 13 studies were large retrospective registry data analyses, six small single-center studies, and two multicenter survey analyses. Limited high-quality evidence was found, and therefore, a modified Delphi process was used. Liaisons from the American Academy of Pediatrics were included in the panel representing critical care, surgical, and hospital medicine expertise for the development of this practice guidance. The title was amended to "practice statement" and "guidance" because Grading of Recommendations, Assessment, Development, and Evaluation methodology was not possible in this administrative work and to align with requirements put forth by the American Academy of Pediatrics.

METHODS

The panel consisted of two groups: a voting group and a writing group. The panel used an iterative collaborative approach to formulate statements on the basis of the literature review and common practice of the pediatric critical care bedside experts and administrators on the task force. Statements were then formulated and presented via an online anonymous voting tool to a voting group using a three-cycle interactive forecasting Delphi method. With each cycle of voting, statements were refined on the basis of votes received and on comments. Voting was conducted between the months of January 2017 and March 2017. The consensus was deemed achieved once 80% or higher scores from the voting group were recorded on any given statement or where there was consensus upon review of comments provided by voters. The Voting Panel was required to vote in all three forecasting events for the final evaluation of the data and inclusion in this work. The writing panel developed admission recommendations by level of care on the basis of voting results.

RESULTS

The panel voted on 30 statements, five of which were multicomponent statements addressing characteristics specific to PICU level of care including team structure, technology, education and training, academic pursuits, and indications for transfer to tertiary or quaternary PICU. Of the remaining 25 statements, 17 reached consensus cutoff score. Following a review of the Delphi results and consensus, the recommendations were written.

CONCLUSIONS

This practice statement and level of care guidance manuscript addresses important specifications for each PICU level of care, including the team structure and resources, technology and equipment, education and training, quality metrics, admission and discharge criteria, and indications for transfer to a higher level of care. The sparse high-quality evidence led the panel to use a modified Delphi process to seek expert opinion to develop consensus-based recommendations where gaps in the evidence exist. Despite this limitation, the members of the Task Force believe that these recommendations will provide guidance to practitioners in making informed decisions regarding pediatric admission or transfer to the appropriate level of care to achieve best outcomes.

Characterization of Long Noncoding RNA and mRNA Profiles in Sepsis-Induced Myocardial Depression

Septic shock with heart dysfunction is very common in intensive care units. However, whether long noncoding RNA (lncRNA) and mRNA profiles differ between patients with and without myocardial depression is unknown. We generated rat models of hypodynamic septic shock induced by lipopolysaccharide. A total of 12 rat models was constructed and heart tissue from each was collected. Whole genomic RNA sequencing was performed on left ventricular tissue; 6,508 novel lncRNAs and 432 annotated lncRNAs were identified in heart samples, and 74 lncRNAs were expressed differently in the sepsis and control groups. Gene ontology term enrichment indicated apoptosis and its related pathways showed obvious enrichment, which suggested cell apoptosis could play a critical role in the process of myocardial depression. Furthermore, we focused on one lncRNA from the Pvt1 gene. By silencing this lncRNA, we demonstrated knockdown of Pvt1 expression could induce cell apoptosis in lipopolysaccharide-induced heart cells, through increasing the expression of c-Myc, Bid, Bax, and caspase-3 and decreasing the expression of Myd88 and Bcl-2, thereby proving its functional role in myocardial depression. These results demonstrate that lncRNAs both participate in and mediate the pathological process of myocardial depression. Our study improves the understanding of the basic molecular mechanisms underlying myocardial depression.

Critical Care Management: Sepsis and Disseminated and Local Infections

Local and systemic infections are a significant cause of morbidity and mortality among immunocompromised children, including but not limited to patients with hematologic and solid malignancies, congenital or acquired immunodeficiencies, or hematopoietic cell or solid organ transplantation patients. Progression to septic shock can be rapid and profound and thus requires specific diagnostic and treatment approaches. This chapter will discuss the diagnosis and the initial hemodynamic management strategies of septic shock in immunocompromised children, including strategies to improve oxygen delivery, reduce metabolic demand, and monitor hemodynamic response to resuscitation. This chapter also discusses strategies to reverse septic shock pathobiology, including the use of both empiric and targeted anti-infective strategies and pharmacologic and cell therapy-based immunomodulation. Specific consideration is also paid to the management of high-risk subpopulations and the care of septic shock patients with resolving injury.

The Trend of β3-Adrenergic Receptor in the Development of Septic Myocardial Depression: A Lipopolysaccharide-Induced Rat Septic Shock Model

Septic shock with low cardiac output is very common in children. However, the mechanism underlying myocardial depression is unclear. The role of β3-AR in the development of myocardial depression in sepsis is unknown. In the present study, we generated an adolescent rat model of hypodynamic septic shock induced by lipopolysaccharide (LPS). Neonatal cardiomyocytes were also treated with LPS to mimic myocardial depression in sepsis, which was confirmed via an in vivo left ventricular hemodynamic study, and measurements of contractility and the Ca2+ transient in isolated adolescent and neonatal cardiomyocytes. After 16 h of LPS treatment, cultured neonatal cardiomyocytes showed a diminished Ca2+ transient amplitude associated with an increase in the β3-AR level. With the addition of a β3-AR agonist, the Ca2+ transient in LPS-treated neonatal rat cardiomyocytes gradually decreased over time; such a change was absent in cells treated with nitric oxide synthase (NOS) inhibitors prior to treatment with a β3-AR agonist. In adolescent rats with septic myocardial depression, cardiac function declined as indicated by decreased MAP, dP/dtmax, and dP/dtmix for 6 h after LPS injection; however, the β3-AR level first increased 2 h after LPS treatment and then decreased 6 h after LPS treatment in the absence of exogenous catecholamines. The results indicate that, in vitro, at the cellular level β3-AR may be involved in the development of myocardial depression (Ca2+ transient depression) in sepsis through NOS signaling pathways; however, in vivo, a complicated mechanism for modulating β3-AR may exist.

Does respiratory variation of inferior vena cava diameter predict fluid responsiveness in spontaneously ventilating children with sepsis

OBJECTIVE

The intent of fluid bolus therapy (FBT) is to increase cardiac output and tissue perfusion, yet only 50% of septic children are fluid responsive. We evaluated respiratory variation of inferior vena cava (IVC) diameter as a predictor of fluid responsiveness.

METHODS

A prospective observational study in the ED of The Royal Children's Hospital, Melbourne, Australia. Patients were spontaneously ventilating children treated with FBT for sepsis-induced acute circulatory failure. IVC ultrasound was performed prior to FBT. Trans-thoracic echocardiography was performed prior to, 5 and 60 min after FBT. IVC collapsibility index and stroke distance were calculated by a blinded Paediatric Emergency Physician and blinded Paediatric Cardiologist, respectively.

RESULTS

Thirty-nine fluid boluses were recorded in 33 children, 28/39 (72%) of which met criteria for fluid responsiveness at 5 min, which was sustained in 2/28 (7%) of initial fluid responders at 60 min. Sensitivity and specificity (95% confidence interval) of IVC collapsibility index were 0.44 (0.25-0.65) and 0.33 (0.10-0.65) with an area under the receiver operator characteristics curve (95% confidence interval) of 0.38 (0.23-0.55) at 5 min. Test characteristics 60 min after fluid bolus administration were not meaningful because of the infrequency of sustained fluid responsiveness in this patient group. There was no significant correlation between IVC collapsibility and fluid responsiveness at 5 or 60 min.

CONCLUSIONS

IVC collapsibility has poor test characteristics for predicting fluid responsiveness in spontaneously ventilating children with sepsis.

Assessment of Myocardial Function and Injury by Echocardiography and Cardiac Biomarkers in African Children With Severe Plasmodium falciparum Malaria

OBJECTIVES

Perturbed hemodynamic function complicates severe malaria. The Fluid Expansion as Supportive Therapy trial demonstrated that fluid resuscitation, involving children with severe malaria, was associated with increased mortality, primarily due to cardiovascular collapse, suggesting that myocardial dysfunction may have a role. The aim of this study was to characterize cardiac function in children with severe malaria.

DESIGN

A prospective observational study with clinical, laboratory, and echocardiographic data collected at presentation (T0) and 24 hours (T1) in children with severe malaria. Cardiac index and ejection fraction were calculated at T0 and T1. Cardiac troponin I and brain natriuretic peptide were measured at T0. We compared clinical and echocardiographic variables in children with and without severe malarial anemia (hemoglobin < 5 mg/dL) at T0 and T1.

SETTING

Mbale Regional Referral Hospital.

PATIENTS

Children 3 months to 12 years old with severe falciparum malaria.

INTERVENTIONS

Usual care.

MEASUREMENTS AND MAIN RESULTS

We enrolled 104 children, median age 23.3 months, including 61 children with severe malarial anemia. Cardiac troponin I levels were elevated (> 0.1 ng/mL) in n equals to 50, (48%), and median brain natriuretic peptide was within normal range (69.1 pg/mL; interquartile range, 48.4-90.8). At T0, median Cardiac index was significantly higher in the severe malarial anemia versus nonsevere malarial anemia group (6.89 vs 5.28 L/min/m) (p = 0.001), which normalized in both groups at T1 (5.60 vs 5.13 L/min/m) (p = 0.452). Cardiac index negatively correlated with hemoglobin, r equals to -0.380 (p < 0.001). Four patients (3.8%) had evidence of depressed cardiac systolic function (ejection fraction < 45%). Overall, six children died, none developed pulmonary edema, biventricular failure, or required diuretic treatment.

CONCLUSIONS

Elevation of cardiac index, due to increased stroke volume, in severe malaria is a physiologic response to circulatory compromise and correlates with anemia. Following whole blood transfusion and antimalarial therapy, cardiac index in severe malarial anemia returns to normal. The majority (> 96%) of children with severe malaria have preserved myocardial systolic function. Although there is evidence for myocardial injury (elevated cardiac troponin I), this does not correlate with cardiac dysfunction.

Noninvasive monitoring of physiologic compromise in acute appendicitis: New insight into an old disease

INTRODUCTION

Physiologic compromise in children with acute appendicitis has heretofore been difficult to measure. We hypothesized that the Compensatory Reserve Index (CRI), a novel adjunctive cardiovascular status indicator, would be low for children presenting with acute appendicitis in proportion to their physiological compromise, and that CRI would rise with fluid resuscitation and surgical management of their disease.

METHODS

Ninety-four children diagnosed with acute appendicitis were monitored with a CipherOx CRI™ M1 pulse oximeter (Flashback Technologies Inc., Boulder, CO). For clarity, CRI=1 indicates supine normovolemia, CRI=0 indicates hemodynamic decompensation (systolic blood pressure<80mmHg), and CRI values between 1 and 0 indicate the proportion of volume reserve remaining before collapse. Results are presented as counts with proportion (%), or mean with 95% confidence interval (CI).

RESULTS

Mean age was 11years old (95% CI: 10-12), and 49 (52%) of the children were male. Fifty-four (57%) had nonperforated appendicitis and 40 (43%) had perforated appendicitis. Mean initial CRI was significantly higher in those with nonperforated appendicitis compared to those with perforated appendicitis (0.57, 95% CI: 0.52-0.63 vs. 0.36, 95% CI: 0.29-0.43; P<0.001). The significant differences in mean CRI values between the two groups remained throughout the course of treatment, but lost its significance at 2h after surgery (0.63, 95% CI: 0.57-0.70 vs. 0.53, 95% CI: 0.46-0.61; P=0.05).

CONCLUSION

Low CRI values in children with perforated appendicitis are indicative of their lower reserve capacity owing to peritonitis and hypovolemia. CRI offers a real-time, noninvasive adjunctive tool to monitor tolerance to volume loss in children.

LEVEL OF EVIDENCE

Study of diagnostic test; Level of evidence: Level III.

Characteristics and Outcomes of Pediatric Heart Failure-Related Emergency Department Visits in the United States: A Population-Based Study

OBJECTIVES

To describe the frequency, characteristics, and outcomes of heart failure-related emergency department (ED) visits in pediatric patients. We aimed to test the hypothesis that these visits are associated with higher admission rates, mortality, and resource utilization.

STUDY DESIGN

A retrospective analysis of the Nationwide Emergency Department Sample for 2010 of patients ≤18 years of age was performed to describe ED visits with and without heart failure. Cases were identified using International Classification of Disease, Ninth Revision, Clinical Modification codes and assessed for factors associated with admission, mortality, and resource utilization.

RESULTS

Among 28.6 million pediatric visits to the ED, there were 5971 (0.02%) heart failure-related cases. Heart failure-related ED patients were significantly more likely to be admitted (59.8% vs 4.01%; OR 35.3, 95% CI 31.5-39.7). Among heart failure-related visits, admission was more common in patients with congenital heart disease (OR 5.0, 95% CI 3.3-7.4) and in those with comorbidities including respiratory failure (OR 78.3, 95% CI 10.4-591) and renal failure (OR 7.9, 95% CI 1.7-36.3). Heart failure-related cases admitted to the hospital had a higher likelihood of death than nonheart failure-related cases (5.9% vs 0.32%, P < .001). Factors associated with mortality included respiratory failure (OR 4.5, 95% CI 2.2-9.2) and renal failure (OR 7.8, 95% CI 2.9-20.7). Heart failure-related ED visits were more expensive than nonheart failure-related ED visits ($1460 [IQR $861-2038] vs $778 [IQR $442-1375] [P < .01].) CONCLUSIONS: Heart failure-related visits represent a minority of pediatric ED visits but are associated with increased hospital admission and resource utilization.

Neonatal Hemodynamics: From Developmental Physiology to Comprehensive Monitoring

Maintenance of neonatal circulatory homeostasis is a real challenge, due to the complex physiology during postnatal transition and the inherent immaturity of the cardiovascular system and other relevant organs. It is known that abnormal cardiovascular function during the neonatal period is associated with increased risk of severe morbidity and mortality. Understanding the functional and structural characteristics of the neonatal circulation is, therefore, essential, as therapeutic hemodynamic interventions should be based on the assumed underlying (patho)physiology. The clinical assessment of systemic blood flow (SBF) by indirect parameters, such as blood pressure, capillary refill time, heart rate, urine output, and central-peripheral temperature difference is inaccurate. As blood pressure is no surrogate for SBF, information on cardiac output and systemic vascular resistance should be obtained in combination with an evaluation of end organ perfusion. Accurate and reliable hemodynamic monitoring systems are required to detect inadequate tissue perfusion and oxygenation at an early stage before this result in irreversible damage. Also, the hemodynamic response to the initiated treatment should be re-evaluated regularly as changes in cardiovascular function can occur quickly. New insights in the understanding of neonatal cardiovascular physiology are reviewed and several methods for current and future neonatal hemodynamic monitoring are discussed.

Fluid Bolus Therapy in Pediatric Sepsis: Current Knowledge and Future Direction

Sepsis is a leading cause of morbidity and mortality in children with a worldwide prevalence in pediatric intensive care units of approximately 8%. Fluid bolus therapy (FBT) is a first line therapy for resuscitation of septic shock and has been a recommendation of international guidelines for nearly two decades. The evidence base supporting these guidelines are based on limited data including animal studies and case control studies. In recent times, evidence suggesting harm from fluid in terms of morbidity and mortality have generated interest in evaluating FBT. In view of this, studies of fluid restrictive strategies in adults and children have emerged. The complexity of studying FBT relates to several points. Firstly, the physiological and haemodynamic response to FBT including magnitude and duration is not well described in children. Secondly, assessment of the circulation is based on non-specific clinical signs and limited haemodynamic monitoring with limited physiological targets. Thirdly, FBT exists in a complex myriad of pathophysiological responses to sepsis and other confounding therapies. Despite this, a greater understanding of the role of FBT in terms of the physiological response and possible harm is warranted. This review outlines current knowledge and future direction for FBT in sepsis.

Double-Blind Randomized Clinical Trial Comparing Dopamine and Epinephrine in Pediatric Fluid-Refractory Hypotensive Septic Shock

OBJECTIVE

We compared efficacy of dopamine and epinephrine as first-line vasoactive therapy in achieving resolution of shock in fluid-refractory hypotensive cold septic shock.

DESIGN

Double-blind, pilot, randomized controlled study.

SETTING

Pediatric emergency and ICU of a tertiary care teaching hospital.

PATIENTS

Consecutive children 3 months to 12 years old, with fluid-refractory hypotensive septic shock, were enrolled between July 2013 and December 2014.

INTERVENTION

Enrolled children were randomized to receive either dopamine (in incremental doses, 10 to 15 to 20 μg/kg/min) or epinephrine (0.1 to 0.2 to 0.3 μg/kg/min) till end points of resolution of shock were achieved. After reaching maximum doses of test drugs, open-label vasoactive was started as per discretion of treating team. Primary outcome was resolution of shock within first hour of resuscitation. The study was registered (CTRI/2014/02/004393) and was approved by institute ethics committee.

MEASUREMENTS AND MAIN RESULTS

We enrolled 29 children in epinephrine group and 31 in dopamine group. Resolution of shock within first hour was achieved in greater proportion of children receiving epinephrine (n = 12; 41%) than dopamine (n = 4; 13%) (odds ratio, 4.8; 95% CI, 1.3-17.2; p = 0.019); the trend persisted even at 6 hours (48.3% vs 29%; p = 0.184). Children in epinephrine group had lower Sequential Organ Function Assessment score on day 3 (8 vs 12; p = 0.05) and more organ failure-free days (24 vs 20 d; p = 0.022). No significant difference in adverse events (16.1% vs 13.8%; p = 0.80) and mortality (58.1% vs 48.3%; p = 0.605) was observed between the two groups.

CONCLUSION

Epinephrine is more effective than dopamine in achieving resolution of fluid-refractory hypotensive cold shock within the first hour of resuscitation and improving organ functions.

Measuring cardiac output in children undergoing cardiac catheterization: comparison between the Fick method and PRAM (pressure recording analytical method)

BACKGROUND

Pressure recording analytical method (PRAM) is a novel, arterial pulse contour method for measuring cardiac output (CO). Validation studies of PRAM in children are few, and have shown contradictory results. The aim of the study was to compare the MostCare^® -PRAM vs the Fick method of cardiac output estimation (reference method).

METHODS

This is a single-center, prospective observational study in 52 pediatric patients who underwent diagnostic right and left heart catheterization. Cardiac index (CI) measurements with the MostCare^® -PRAM vs the Fick method were obtained under hemodynamically stable conditions.

RESULTS

Forty CI measurements were performed. The data showed good agreement between CI_Fick and CI_PRAM : r² = 0.90 (P < 0.001), mean bias -0.075, limits of agreement from -0.56 to 0.41. The percentage error was 17%. Comparable results were obtained for patients <20 kg (r² = 0.87, P < 0.001), mean bias -0.135, limits of agreement from -0.35 to 0.62, percentage of error 17%.

CONCLUSIONS

In pediatric patients undergoing diagnostic right and left heart catheterization, the MostCare^® -PRAM was shown to estimate CI with a good level of agreement with the Fick method measurements.

The vulnerable microcirculation in the critically ill pediatric patient

In neonates, cardiovascular system development does not stop after the transition from intra-uterine to extra-uterine life and is not limited to the macrocirculation. The microcirculation (MC), which is essential for oxygen, nutrient, and drug delivery to tissues and cells, also develops. Developmental changes in the microcirculatory structure continue to occur during the initial weeks of life in healthy neonates. The physiologic hallmarks of neonates and developing children make them particularly vulnerable during critical illness; however, the cardiovascular monitoring possibilities are limited compared with critically ill adult patients. Therefore, the development of non-invasive methods for monitoring the MC is necessary in pediatric critical care for early identification of impending deterioration and to enable the initiation and titration of therapy to ensure cell survival. To date, the MC may be non-invasively monitored at the bedside using hand-held videomicroscopy, which provides useful information regarding the microcirculation. There is an increasing number of studies on the MC in neonates and pediatric patients; however, additional steps are necessary to transition MC monitoring from bench to bedside. The recently introduced concept of hemodynamic coherence describes the relationship between changes in the MC and macrocirculation. The loss of hemodynamic coherence may result in a depressed MC despite an improvement in the macrocirculation, which represents a condition associated with adverse outcomes. In the pediatric intensive care unit, the concept of hemodynamic coherence may function as a framework to develop microcirculatory measurements towards implementation in daily clinical practice.

An observational study using ultrasound to assess physiological changes following fluid bolus administration in paediatric sepsis in the emergency department

Background

Fluid bolus administration is widely recommended as part of the initial treatment of paediatric sepsis, though the physiological benefits and harms are unclear. The primary aim of this study is to determine the effect of fluid bolus administration on cardiac index (CI). Secondary aims are to determine the effect of fluid bolus administration on extra-vascular lung water (EVLW), whether fluid responsiveness can be predicted by inferior vena cava (IVC) collapsibility, and whether fluid responsiveness correlates with changes in vital signs.

Methods/design

A prospective observational study of children presenting to the Emergency Department of The Royal Children’s Hospital with clinically diagnosed sepsis requiring fluid bolus administration. Prior to fluid bolus administration, an echocardiogram, lung ultrasound, and IVC ultrasound will be performed, and vital signs recorded. These will be repeated 5 min after and 60 min after fluid bolus administration. Recorded echocardiograms and lung/IVC ultrasound will be evaluated independently by a paediatric cardiologist and paediatric emergency physician, respectively, blinded to the patient identity and time of examination relative to time of fluid bolus administration. Fifty patients will be enrolled in the study based on a precision based sample size calculation. Results will be analysed for change in CI and change in EVLW 5 min after and 60 min after fluid bolus administration compared to baseline, IVC collapsibility as a predictor of fluid responsiveness, and the relationship between fluid responsiveness and changes in vital signs.

Discussion

This study will explore assumptions about the effect of fluid boluses on CI in children with sepsis, and will provide evidence for secondary effects on other organ systems. This may lead to novel methods for assessment and decision making in the initial resuscitation of paediatric sepsis in clinical and research settings, and will likely influence the design of future interventional studies in this arena.

Trial registration

The study is registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12614000824662; 04 August 2014).