Shock Index-A Useful Noninvasive Marker Associated With Age-Specific Early Mortality in Children With Severe Sepsis and Septic Shock: Age-Specific Shock Index Cut-Offs

The Shock Index among Children Presenting to the Emergency Department: Analysis of Nationally Representative Sample

BACKGROUND

The Shock Index (SI) is emerging as a potentially useful measure among children with injury or suspected sepsis.

OBJECTIVE

The aim of this study was to evaluate the distribution of the SI and evaluate its association with clinical outcomes among all children presenting to the emergency department (ED).

METHODS

A complex survey of nonfederal U.S. ED encounters from 2016 through 2021 was analyzed. Among children, the Pediatric Age-Adjusted Shock Index (SIPA), Pediatric Shock Index (PSI), and the Temperature- and Age-Adjusted Shock Index (TAMSI) were analyzed. The association of these criteria with disposition, acuity, medication administration, diagnoses and procedures was analyzed.

RESULTS

A survey-weighted 81.5 million ED visits were included for children aged 4-16 years and 117.2 million visits were included for children aged 1-12 years. SI could be calculated for 78.6% of patients aged 4-16 years and 57.9% of patients aged 1-12 years. An abnormal SI was present in 15.9%, 11.1%, and 31.7% when using the SIPA, PSI, and TAMSI, respectively. With all criteria, an elevated SI was associated with greater hospitalization. The SIPA and PSI were associated with triage acuity. All criteria were associated with medical interventions, including provision of IV fluids and acquisition of blood cultures.

CONCLUSIONS

An elevated SI is indicative of greater resource utilization needs among children in the ED. When using any criteria, an elevated SI was associated with clinically important outcomes. Further research is required to evaluate the distribution of the SI in children and to investigate its potential role within existing triage algorithms for children in the ED.

Diastolic blood pressure impact on pediatric refractory septic shock outcomes

BACKGROUND

Septic shock is the progression of sepsis, defined as cardiovascular dysfunction during systemic infection, and it has a mortality rate of 40 %-80 %. Loss of vascular tone is an important pathophysiological feature of septic shock. Diastolic blood pressure (DBP) was reported to be associated with vascular tone. This study aimed to identify the associations of several hemodynamic indices, especially DBP, with outcome in pediatric septic shock to allow for timely interventions.

METHODS

Children with persistent catecholamine-resistant shock had a pulse index continuous cardiac output (PiCCO®) system implanted for invasive hemodynamic monitoring and were enrolled in the current study. Serial cardiac index, systemic vascular resistance index (SVRI), systolic blood pressure (SBP), mean arterial pressure (MAP), and DBP were recorded during the first 24 h following PiCCO® initiation. All hemodynamic parameters associated with 28-day mortality were further analyzed using receiver operating characteristic curve analysis.

RESULTS

Thirty-three children with persistent catecholamine-resistant shock were enrolled. The median age was 12 years and the youngest children were 5 years old. Univariate analysis noted that SVRI, SBP, MAP, and DBP were significantly higher, and shock index was significant lower, in survivors compared with non-survivors (p < 0.05). In the multivariate analysis, only SVRI and DBP remained independent predictors of 28-day mortality. DBP had the best correlation with SVRI (r = 0.718, n = 219, p < 0.001). The area under the receiver operating characteristic curves of SVRI and DBP for predicting 28-day mortality during the first 24 h of persistent catecholamine-resistant shock were >0.75, indicating a good prediction for mortality.

CONCLUSIONS

DBP correlated well with SVRI and it can serve as a predictor for mortality in pediatric septic shock. Furthermore, DBP was a superior discriminator of mortality when compared with SBP and MAP. A lower DBP was an independent hemodynamic factor associated with 28-day mortality.

Diastolic/systolic blood pressure ratio for predicting febrile children with sepsis and progress to septic shock in the emergency department

OBJECTIVE

Given the scarcity of studies analyzing the clinical predictors of pediatric septic cases that would progress to septic shock, this study aimed to determine strong predictors for pediatric emergency department (PED) patients with sepsis at risk for septic shock and mortality.

METHODS

We conducted chart reviews of patients with ≥ 2 age-adjusted quick Sequential Organ Failure Assessment score (qSOFA) criteria to recognize patients with an infectious disease in two tertiary PEDs between January 1, 2021, and April 30, 2022. The age range of included patients was 1 month to 18 years. The primary outcome was development of septic shock within 48 h of PED attendance. The secondary outcome was sepsis-related 28-day mortality. Initial important variables in the PED and hemodynamics with the highest and lowest values during the first 24 h of admission were also analyzed.

RESULTS

Overall, 417 patients were admitted because of sepsis and met the eligibility criteria for the study. Forty-nine cases progressed to septic shock within 48 h after admission and 368 were discharged without progression. General demographics, laboratory data, and hemodynamics were analyzed by multivariate analysis. Only the minimum diastolic blood pressure/systolic blood pressure ratio (D/S ratio) during the first 24 h after admission remained as an independent predictor of progression to septic shock and 28-day mortality. The best cutoff values of the D/S ratio for predicting septic shock and 28-day mortality were 0.52 and 0.47, respectively.

CONCLUSIONS

The D/S ratio is a practical bedside scoring system in the PED and had good discriminative ability in predicting the progression of septic shock and in-hospital mortality in PED patients. Further validation is essential in other settings.

A Temperature- and Age-Adjusted Shock Index for Emergency Department Identification of Pediatric Sepsis

OBJECTIVE

To empirically derive a novel temperature- and age-adjusted mean shock index (TAMSI) for early identification of sepsis and septic shock in children with suspected infection.

METHODS

We performed a retrospective cohort study of children aged 1 month to <18 years presenting to a single emergency department with suspected infection over a 10-year period. TAMSI was defined as (pulse rate - 10 × [temperature - 37])/(mean arterial pressure). The primary outcome was sepsis, and the secondary outcome was septic shock. In the two-thirds training set, we determined TAMSI cutoffs for each age group using a minimum sensitivity of 85% and Youden Index. In the one-third validation data set, we calculated test characteristics for the TAMSI cutoffs and compared them with those for the Pediatric Advanced Life Support (PALS) tachycardia or systolic hypotension cutoffs.

RESULTS

In the sepsis validation data set, the sensitivity-targeting TAMSI cutoff yielded a sensitivity of 83.5% (95% confidence interval [CI] 81.7% to 85.4%) and specificity of 42.8% (95% CI 42.4% to 43.3%) versus a sensitivity of 77.7% (95% CI 75.7% to 79.8%) and specificity of 60.0% (95% CI 59.5% to 60.4%) for PALS. For septic shock, the sensitivity-targeting TAMSI cutoff achieved a sensitivity of 81.3% (95% CI 75.2% to 87.4%) and a specificity of 83.5% (95% CI 83.2% to 83.8%) versus a sensitivity of 91.0% (95% CI 86.5% to 95.5%) and a specificity of 58.8% (95% CI 58.4% to 59.3%) for PALS. TAMSI yielded an increased positive likelihood ratio and similar negative likelihood ratio versus PALS.

CONCLUSIONS

TAMSI achieved a similar negative likelihood ratio and improved positive likelihood ratio compared with PALS vital sign cutoffs for the prediction of septic shock, but it did not improve on PALS for sepsis prediction, among children with suspected infection.

Reporting of Social Determinants of Health in Pediatric Sepsis Studies

OBJECTIVE

Standardized, consistent reporting of social determinants of health (SDOH) in studies on children with sepsis would allow for: 1) understanding the association of SDOH with illness severity and outcomes, 2) comparing populations and extrapolating study results, and 3) identification of potentially modifiable socioeconomic factors for policy makers. We, therefore, sought to determine how frequently data on SDOH were reported, which factors were collected and how these factors were defined in studies of sepsis in children.

DATA SOURCES AND SELECTION

We reviewed 106 articles (published between 2005 and 2020) utilized in a recent systematic review on physiologic criteria for pediatric sepsis.

DATA EXTRACTION

Data were extracted by two reviewers on variables that fell within the World Health Organization's SDOH categories.

DATA SYNTHESIS

SDOH were not the primary outcome in any of the included studies. Seventeen percent of articles (18/106) did not report on any SDOH, and a further 36.8% (39/106) only reported on gender/sex. Of the remaining 46.2% of articles, the most reported SDOH categories were preadmission nutritional status (35.8%, 38/106) and race/ethnicity (18.9%, 20/106). However, no two studies used the same definition of the variables reported within each of these categories. Six studies reported on socioeconomic status (3.8%, 6/106), including two from upper-middle-income and four from lower middle-income countries. Only three studies reported on parental education levels (2.8%, 3/106). No study reported on parental job security or structural conflict.

CONCLUSIONS

We found overall low reporting of SDOH and marked variability in categorizations and definitions of SDOH variables. Consistent and standardized reporting of SDOH in pediatric sepsis studies is needed to understand the role these factors play in the development and severity of sepsis, to compare and extrapolate study results between settings and to implement policies aimed at improving socioeconomic conditions related to sepsis.

Shock Index in the early assessment of febrile children at the emergency department: a prospective multicentre study

OBJECTIVE

(1) To derive reference values for the Shock Index (heart rate/systolic blood pressure) based on a large emergency department (ED) population of febrile children and (2) to determine the diagnostic value of the Shock Index for serious illness in febrile children.

DESIGN/SETTING

Observational study in 11 European EDs (2017-2018).

PATIENTS

Febrile children with measured blood pressure.

MAIN OUTCOME MEASURES

Serious bacterial infection (SBI), invasive bacterial infection (IBI), immediate life-saving interventions (ILSIs) and intensive care unit (ICU) admission. The association between high Shock Index (>95th centile) and each outcome was determined by logistic regression adjusted for age, sex, referral, comorbidity and temperature. Additionally, we calculated sensitivity, specificity and negative/positive likelihood ratios (LRs).

RESULTS

Of 5622 children, 461 (8.2%) had SBI, 46 (0.8%) had IBI, 203 (3.6%) were treated with ILSI and 69 (1.2%) were ICU admitted. High Shock Index was associated with SBI (adjusted OR (aOR) 1.6 (95% CI 1.3 to 1.9)), ILSI (aOR 2.5 (95% CI 2.0 to 2.9)), ICU admission (aOR 2.2 (95% CI 1.4 to 2.9)) but not with IBI (aOR: 1.5 (95% CI 0.6 to 2.4)). For the different outcomes, sensitivity for high Shock Index ranged from 0.10 to 0.15, specificity ranged from 0.95 to 0.95, negative LRs ranged from 0.90 to 0.95 and positive LRs ranged from 1.8 to 2.8.

CONCLUSIONS

High Shock Index is associated with serious illness in febrile children. However, its rule-out value is insufficient which suggests that the Shock Index is not valuable as a screening tool for all febrile children at the ED.

Criteria for Pediatric Sepsis-A Systematic Review and Meta-Analysis by the Pediatric Sepsis Definition Taskforce

OBJECTIVE

To determine the associations of demographic, clinical, laboratory, organ dysfunction, and illness severity variable values with: 1) sepsis, severe sepsis, or septic shock in children with infection and 2) multiple organ dysfunction or death in children with sepsis, severe sepsis, or septic shock.

DATA SOURCES

MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched from January 1, 2004, and November 16, 2020.

STUDY SELECTION

Case-control studies, cohort studies, and randomized controlled trials in children greater than or equal to 37-week-old postconception to 18 years with suspected or confirmed infection, which included the terms "sepsis," "septicemia," or "septic shock" in the title or abstract.

DATA EXTRACTION

Study characteristics, patient demographics, clinical signs or interventions, laboratory values, organ dysfunction measures, and illness severity scores were extracted from eligible articles. Random-effects meta-analysis was performed.

DATA SYNTHESIS

One hundred and six studies met eligibility criteria of which 81 were included in the meta-analysis. Sixteen studies (9,629 patients) provided data for the sepsis, severe sepsis, or septic shock outcome and 71 studies (154,674 patients) for the mortality outcome. In children with infection, decreased level of consciousness and higher Pediatric Risk of Mortality scores were associated with sepsis/severe sepsis. In children with sepsis/severe sepsis/septic shock, chronic conditions, oncologic diagnosis, use of vasoactive/inotropic agents, mechanical ventilation, serum lactate, platelet count, fibrinogen, procalcitonin, multi-organ dysfunction syndrome, Pediatric Logistic Organ Dysfunction score, Pediatric Index of Mortality-3, and Pediatric Risk of Mortality score each demonstrated significant and consistent associations with mortality. Pooled mortality rates varied among high-, upper middle-, and lower middle-income countries for patients with sepsis, severe sepsis, and septic shock (p < 0.0001).

CONCLUSIONS

Strong associations of several markers of organ dysfunction with the outcomes of interest among infected and septic children support their inclusion in the data validation phase of the Pediatric Sepsis Definition Taskforce.

Hemodynamic monitoring and management of pediatric septic shock

Sepsis remains a major cause of morbidity and mortality among children worldwide. Furthermore, refractory septic shock and multiple organ dysfunction syndrome are the most critical groups which account for a high mortality rate in pediatric sepsis, and their clinical course often deteriorates rapidly. Resuscitation based on hemodynamics can provide objective values for identifying the severity of sepsis and monitoring the treatment response. Hemodynamics in sepsis can be divided into two groups: basic and advanced hemodynamic parameters. Previous therapeutic guidance of early-goal directed therapy (EGDT), which resuscitated based on the basic hemodynamics (central venous pressure and central venous oxygen saturation (ScvO2)) has lost its advantage compared with “usual care”. Optimization of advanced hemodynamics, such as cardiac output and systemic vascular resistance, has now been endorsed as better therapeutic guidance for sepsis. Despite this, there are still some important hemodynamics associated with prognosis. In this article, we summarize the common techniques for hemodynamic monitoring, list important hemodynamic parameters related to outcomes, and update evidence-based therapeutic recommendations for optimizing resuscitation in pediatric septic shock.

Comparison of non-invasive physiological assessment tools between simple and perforated appendicitis in children

PURPOSE

The role of non-invasive measures of physiologic reserve, specifically the Compensatory reserve index (CRI) and the Shock index pediatric age-adjusted (SIPA), is unknown in the management of children with acute appendicitis. CRI is a first-in-class algorithm that uses pulse oximetry waveforms to continuously monitor central volume status loss. SIPA is a well-validated, but a discontinuous measure of shock that has been calibrated for children.

METHODS

Children with suspected acute appendicitis (2-17 years old) were prospectively enrolled at a single center from 2014 to 2015 and monitored with a CipherOx CRI™ M1 pulse oximeter. CRI values range from 1 (normovolemia) to 0 (life-threatening hypovolemia). SIPA is calculated by dividing heart rate by systolic blood pressure and categorized as normal or abnormal, based on age-specific cutoffs. Univariate and multivariable regression models were developed with simple versus perforated appendicitis as the outcome.

RESULTS

Almost half the patients (45/94, 48%) had perforated appendicitis. On univariate analysis, the median admission CRI value was significantly higher (0.60 versus 0.33, p < 0.001) and the ED SIPA values were significantly lower (0.90 versus 1.10, p = 0.002) in children with simple versus perforated appendicitis. In a multivariable model, only CRI significantly detected differences in the physiologic state between patients with simple and perforated appendicitis.

CONCLUSIONS

CRI is a non-invasive measure of physiologic reserve that may be used to accurately guide early management of children with acute simple versus perforated appendicitis.

Lactate Measurements and Their Association With Mortality in Pediatric Severe Sepsis in India: Evidence That 6-Hour Level Performs Best

PURPOSE

To investigate association of static and dynamic lactate indices with early mortality (within 48 hours of admission), as well as need for vasopressors and mechanical ventilation in pediatric severe sepsis/shock. To explore optimal cutoffs of lactate indices. We hypothesized that dynamic indices are superior to static indices in predicting early mortality.

METHODS

This prospective cohort study involved children (aged <14 years) admitted in emergency department, tertiary care teaching hospital in North India with severe sepsis/shock (2015-2016). Arterial lactate was measured at admission (X0) and after 6 hours (X6). Primary outcome of the measurement was early mortality. Association between lactate indices- lactate at 0 hours (Lac0), lactate after 6 hours (Lac6), time-weighted average (LacTW), delta (ΔLac), clearance (LacCl%) and early mortality, need for vasopressors, and mechanical ventilation-was assessed using Student t test/Mann-Whitney test. Area under the receiver operating characteristic curve (AUROC) for early mortality deduced for all lactate indices and compared with reference (Lac0). Optimal cutoffs (maximizing both sensitivity and specificity) and their positive predictive value (PPV) and negative predictive value (NPV) were determined.

RESULTS

During the study period, 116 children were assessed. Septic shock was present at admission in 56.9% children; 50% of children died during the next 48 hours. Lac0, Lac6, and LacTW were significantly higher, and LacCl% was lower in nonsurvivors versus survivors (all P < .001). Lac6 (0.837 [0.76-0.91]) had significantly higher AUROC (95% confidence interval) than Lac0 (0.77; P = .03). Abnormal lactate metrics (higher Lac0, Lac6, LacTW, and lower LacCl%) were associated with vasopressors need and mechanical ventilation. On logistic regression, Lac6 emerged as an independent predictor of early mortality as well as vasopressor and mechanical ventilation need. The optimal cutoff of Lac6 for identifying early mortality with good sensitivity, specificity, PPV, and NPV was ≥2.65 (76, 85, 83, 78).

CONCLUSIONS

Lactate6 is the best marker associated with early mortality and higher level of care in severe sepsis/septic shock in resource-poor regions.

Characteristics of Febrile Children Admitted to the ICU Following an Unscheduled ED Revisit Within 72 h, a Case-Control Study

Objective: The purpose of this article was to demonstrate related characteristics of intensive care unit (ICU) admission after an unscheduled revisit by febrile children visiting the emergency department (ED). Method: We performed a retrospective study in a tertiary medical center from 2010 to 2016. Patients whose chief complaint was fever and who were admitted to the ICU following a 72-h return visit to the ED were included, and we selected patients who were discharged from the same emergency department for comparison. Results: During the study period, 54 (0.03%) patients met the inclusion criteria, and 216 patients were selected for the matched control group. Regarding clinical variables on initial ED visit, visiting during the night shift (66.7 vs. 46.8%, p = 0.010), shorter length of 1st ED stay (2.5 ± 2.63 vs. 3.5 ± 3.44 h, p = 0.017), and higher shock index (SI) (1.6 ± 0.07 vs. 1.4 ± 0.02, p = 0.008) were associated with ICU admission following a return visit. On the return ED visit, we found that clinical variables such as elevated heart rate, SI, white blood cell count, and C-reactive protein level were all associated with ICU admission. Furthermore, elevated SI and pediatric age-adjusted (SIPA) values were observed in the study group in both the initial (42.2 vs. 20.1%, OR:2.3 (1.37-4.31), p = 0.002) and return ED visits (29.7 vs. 6.9%, OR: 4.6 (2.42-8.26), p < 0.001). Conclusion: For children who visited the emergency department with a febrile complaint, elevated SIPA values on the initial ED visit were associated with ICU admission following an unscheduled ED revisit within 72 h.

Optimal Hemodynamic Parameter to Predict the Neurological Outcome in Out-of-Hospital Cardiac Arrest Survivors Treated with Target Temperature Management

Current guidelines suggest the maintenance of systolic blood pressure (SBP) at >90 mmHg and mean arterial pressure (MAP) at >65 mmHg in postcardiac arrest patients. There remains a lack of clarity regarding optimal values and timing of blood pressure parameters associated with the improvement of neurologic outcome. We investigated the association of time-weighted average (TWA) blood pressure parameters with favorable neurological outcome (FO) in postcardiac arrest patients. This was a registry-based observational study with consecutive adult out-of-hospital cardiac arrest (OHCA) survivors who were treated using targeted temperature management (TTM). During 72 hours of TTM period, we abstracted hemodynamic parameters such as SBP, diastolic blood pressure, pulse rate (PR), and MAP. Shock index (SI; PR/SBP) and modified shock index (MSI; PR/MAP) were calculated from each measured hemodynamics. Logistic regression was performed to assess the associations between TWA blood pressure parameters and FO, defined as cerebral performance category 1 or 2 at hospital discharge. Among the 173 patients (median age: 58 years; 64% male), 51 (29.3%) had FO in this study. MAP, SI, and MSI at 6 hours after return of spontaneous circulation (ROSC) showed considerable differences in patients with FO (MAP: 89.1 ± 14.7 vs. 83.6 ± 15.8 mmHg, p = 0.033, SI: 0.7 ± 0.2 vs. 0.9 ± 0.9, p = 0.002, MSI: 1.0 ± 0.3 vs. 1.2 ± 0.3, p ≤ 0.001). Among them, MSI, especially at 6 hours, had the highest area under the curve for prediction of FO (0.685; 95% confidence interval: 0.597-0.772, p < 0.001). Also, MSI <1.0 had a sensitivity of 64.7%, a specificity of 64.2% to predict FO. In comatose survivors of OHCA with TTM, MSI at 6 hours after ROSC had the highest prognostic value for neurologic outcome among blood pressure parameters.

Shock index in the emergency department: utility and limitations

Shock index (SI) is defined as the heart rate (HR) divided by systolic blood pressure (SBP). It has been studied in patients either at risk of or experiencing shock from a variety of causes: trauma, hemorrhage, myocardial infarction, pulmonary embolism, sepsis, and ruptured ectopic pregnancy. While HR and SBP have traditionally been used to characterize shock in these patients, they often appear normal in the compensatory phase of shock and can be confounded by factors such as medications (eg, antihypertensives, beta-agonists). SI >1.0 has been widely found to predict increased risk of mortality and other markers of morbidity, such as need for massive transfusion protocol activation and admission to intensive care units. Recent research has aimed to study the use of SI in patients immediately on arrival to the emergency department (ED). In this review, we summarize the literature pertaining to use of SI across a variety of settings in the management of ED patients, in order to provide context for use of this measure in the triage and management of critically ill patients.