Acute Cardiovascular Manifestations in 286 Children With Multisystem Inflammatory Syndrome Associated With COVID-19 Infection in Europe.

BACKGROUND: The aim of the study was to document cardiovascular clinical findings, cardiac imaging, and laboratory markers in children presenting with the novel multisystem inflammatory syndrome associated with coronavirus disease 2019 (COVID-19) infection. METHODS: This real-time internet-based survey has been endorsed by the Association for European Paediatric and Congenital Cardiologists Working Groups for Cardiac Imaging and Cardiovascular Intensive Care. Children 0 to 18 years of age admitted to a hospital between February 1 and June 6, 2020, with a diagnosis of an inflammatory syndrome and acute cardiovascular complications were included. RESULTS: A total of 286 children from 55 centers in 17 European countries were included. The median age was 8.4 years (interquartile range, 3.8-12.4 years) and 67% were boys. The most common cardiovascular complications were shock, cardiac arrhythmias, pericardial effusion, and coronary artery dilatation. Reduced left ventricular ejection fraction was present in over half of the patients, and a vast majority of children had raised cardiac troponin when checked. The biochemical markers of inflammation were raised in most patients on admission: elevated C-reactive protein, serum ferritin, procalcitonin, N-terminal pro B-type natriuretic peptide, interleukin-6 level, and D-dimers. There was a statistically significant correlation between degree of elevation in cardiac and biochemical parameters and the need for intensive care support (P<0.05). Polymerase chain reaction for severe acute respiratory syndrome coronavirus 2 was positive in 33.6%, whereas immunoglobulin M and immunoglobulin G antibodies were positive in 15.7% cases and immunoglobulin G in 43.6% cases, respectively, when checked. One child in the study cohort died. CONCLUSIONS: Cardiac involvement is common in children with multisystem inflammatory syndrome associated with the Covid-19 pandemic. The majority of children have significantly raised levels of N-terminal pro B-type natriuretic peptide, ferritin, D-dimers, and cardiac troponin in addition to high C-reactive protein and procalcitonin levels. In comparison with adults with COVID-19, mortality in children with multisystem inflammatory syndrome associated with COVID-19 is uncommon despite multisystem involvement, very elevated inflammatory markers, and the need for intensive care support.

Serum citrullinated histone H3 concentrations differentiate patients with septic verses non-septic shock and correlate with disease severity.

PURPOSE: Microbial infection stimulates neutrophil/macrophage/monocyte extracellular trap formation, which leads to the release of citrullinated histone H3 (CitH3) catalyzed by peptidylarginine deiminase (PAD) 2 and 4. Understanding these molecular mechanisms in the pathogenesis of septic shock will be an important next step for developing novel diagnostic and treatment modalities. We sought to determine the expression of CitH3 in patients with septic shock, and to correlate CitH3 levels with PAD2/PAD4 and clinically relevant outcomes. METHODS: Levels of CitH3 were measured in serum samples of 160 critically ill patients with septic and non-septic shock, and healthy volunteers. Analyses of clinical and laboratory characteristics of patients were conducted. RESULTS: Levels of circulating CitH3 at enrollment were significantly increased in septic shock patients (n = 102) compared to patients hospitalized with non-infectious shock (NIC) (n = 32, p < 0.0001). The area under the curve (95% CI) for distinguishing septic shock from NIC using CitH3 was 0.76 (0.65-0.86). CitH3 was positively correlated with PAD2 and PAD4 concentrations and Sequential Organ Failure Assessment Scores [total score (r = 0.36, p < 0.0001)]. The serum levels of CitH3 at 24 h (p < 0.01) and 48 h (p < 0.05) were significantly higher in the septic patients that did not survive. CONCLUSION: CitH3 is increased in patients with septic shock. Its serum concentrations correlate with disease severity and prognosis, which may yield vital insights into the pathophysiology of sepsis.

Renin and Survival in Patients Given Angiotensin II for Catecholamine-Resistant Vasodilatory Shock. A Clinical Trial.

Rationale: Exogenous angiotensin II increases mean arterial pressure in patients with catecholamine-resistant vasodilatory shock (CRVS). We hypothesized that renin concentrations may identify patients most likely to benefit from such therapy.Objectives: To test the kinetic changes in renin concentrations and their prognostic value in patients with CRVS.Methods: We analyzed serum samples from patients enrolled in the ATHOS-3 (Angiotensin II for the Treatment of High-Output Shock) trial for renin, angiotensin I, and angiotensin II concentrations before the start of administration of angiotensin II or placebo and after 3 hours.Measurements and Main Results: Baseline serum renin concentration (normal range, 2.13-58.78 pg/ml) was above the upper limits of normal in 194 of 255 (76%) study patients with a median renin concentration of 172.7 pg/ml (interquartile range [IQR], 60.7 to 440.6 pg/ml), approximately threefold higher than the upper limit of normal. Renin concentrations correlated positively with angiotensin I/II ratios (r = 0.39; P < 0.001). At 3 hours after initiation of angiotensin II therapy, there was a 54.3% reduction (IQR, 37.9% to 66.5% reduction) in renin concentration compared with a 14.1% reduction (IQR, 37.6% reduction to 5.1% increase) with placebo (P < 0.0001). In patients with renin concentrations above the study population median, angiotensin II significantly reduced 28-day mortality to 28 of 55 (50.9%) patients compared with 51 of 73 patients (69.9%) treated with placebo (unstratified hazard ratio, 0.56; 95% confidence interval, 0.35 to 0.88; P = 0.012) (P = 0.048 for the interaction).Conclusions: The serum renin concentration is markedly elevated in CRVS and may identify patients for whom treatment with angiotensin II has a beneficial effect on clinical outcomes.Clinical trial registered with www.clinicaltrials.gov (NCT02338843).

Arterial or cuff pressure: Clinical predictors among patients in shock in a critical care resuscitation unit.

OBJECTIVES: Blood pressure (BP) measurement is essential for managing patients with hypotension. There are differences between invasive arterial blood pressure (IABP) and noninvasive blood pressure (NIBP) measurements. However, the clinical applicability of these differences in patients with shock [need for vasopressor or serum lactate ≥ 4 millimole per liter (mmol/L)] has not been reported. This study investigated differences in IABP and NIBP as well as changes in clinical management in critically ill patients with shock. METHODS: This was a retrospective study involving adult patients admitted to the Critical Care Resuscitation Unit (CCRU). Adult patients who received IABP upon admission between 01/01/2017-12/31/2017 with non-hypertensive diseases were eligible. The primary outcome, clinically relevant difference (CRD), was defined as difference of 10 mm of mercury (mmHg) between IABP and NIBP and change of blood pressure management according to goal mean arterial pressure (MAP) ≥ 65 mmHg. We performed forward stepwise multivariable logistic regression to measure associations. RESULTS: Sample size calculation recommended 200 patients, and we analyzed 263. 121 (46%) patients had shock, 23 (9%) patients had CRD. Each mmol/L increase in serum lactate was associated with 11% higher likelihood of having CRD (OR 1.11, 95%CI 1.002-1.2). Peripheral artery disease and any kidney disease was significantly associated with higher likelihood of MAP difference ≥ 10 mmHg. CONCLUSION: Approximately 9% of patients with shock had clinically-relevant MAP difference. Higher serum lactate was associated with higher likelihood of CRD. Until further studies are available, clinicians should consider using IABP in patients with shock.

Metabolic Systems Analysis of Shock-Induced Endotheliopathy (SHINE) in Trauma: A New Research Paradigm.

OBJECTIVE: Investigate the endothelial cell phenotype (s) that causes Shock-Induced Endotheliopathy in trauma. BACKGROUND: We have studied more than 2750 trauma patients and identified that patients with high circulating syndecan-1 (endothelial glycocalyx damage marker) in plasma have an increased mortality rate compared with patients with lower levels. Notably, we found that patients suffering from the same trauma severity could develop significantly different degrees of endothelial dysfunction as measured by syndecan-1. METHODS: Prospective observational study of 20 trauma patients admitted to a Level 1 Trauma Centre and 20 healthy controls. Admission plasma syndecan-1 level and mass spectrometry were measured and analyzed by computational network analysis of our genome-scale metabolic model of the microvascular endothelial cell function. RESULTS: Trauma patients had a significantly different endothelial metabolic profile compared with controls. Among the patients, 4 phenotypes were identified. Three phenotypes were independent of syndecan-1 levels. We developed genome-scale metabolic models representative of the observed phenotypes. Within these phenotypes, we observed differences in the cell fluxes from glucose and palmitate to produce Acetyl-CoA, and secretion of heparan sulfate proteoglycan (component of syndecan-1). CONCLUSIONS: We confirm that trauma patients have a significantly different metabolic profile compared with controls. A minimum of 4 shock-induced endotheliopathy phenotypes were identified, which were independent of syndecan-1level (except 1 phenotype) verifying that the endothelial response to trauma is heterogeneous and most likely driven by a genetic component. Moreover, we introduced a new research tool in trauma by using metabolic systems biology, laying the foundation for personalized medicine.

The Use of Central Venous to Arterial Carbon Dioxide Tension Gap for Outcome Prediction in Critically Ill Patients: A Systematic Review and Meta-Analysis.

OBJECTIVES: In this systematic review and meta-analysis, we assessed whether a high CO2 gap predicts mortality in adult critically ill patients with circulatory shock. DATA SOURCES: A systematic search of MEDLINE and EMBASE electronic databases from inception to October 2019. STUDY SELECTION: Studies from adult (age ≥ 18 yr) ICU patients with shock reporting CO2 gap and outcomes of interest. Case reports and conference abstracts were excluded. DATA EXTRACTION: Data extraction and study quality assessment were performed independently in duplicate. DATA SYNTHESIS: We used the Newcastle-Ottawa Scale to assess methodological study quality. Effect sizes were pooled using a random-effects model. The primary outcome was mortality (28 d and hospital). Secondary outcomes were ICU length of stay, hospital length of stay, duration of mechanical ventilation, use of renal replacement therapy, use of vasopressors and inotropes, and association with cardiac index, lactate, and central venous oxygen saturation. CONCLUSIONS: We included 21 studies (n = 2,155 patients) from medical (n = 925), cardiovascular (n = 685), surgical (n = 483), and mixed (n = 62) ICUs. A high CO2 gap was associated with increased mortality (odds ratio, 2.22; 95% CI, 1.30-3.82; p = 0.004) in patients with shock, but only those from medical and surgical ICUs. A high CO2 gap was associated with higher lactate levels (mean difference 0.44 mmol/L; 95% CI, 0.20-0.68 mmol/L; p = 0.0004), lower cardiac index (mean difference, -0.76 L/min/m; 95% CI, -1.04 to -0.49 L/min/m; p = 0.00001), and central venous oxygen saturation (mean difference, -5.07; 95% CI, -7.78 to -2.37; p = 0.0002). A high CO2 gap was not associated with longer ICU or hospital length of stays, requirement for renal replacement therapy, longer duration of mechanical ventilation, or higher vasopressors and inotropes use. Future studies should evaluate whether resuscitation aimed at closing the CO2 gap improves mortality in shock.

Angiotensin I and angiotensin II concentrations and their ratio in catecholamine-resistant vasodilatory shock.

BACKGROUND: In patients with vasodilatory shock, plasma concentrations of angiotensin I (ANG I) and II (ANG II) and their ratio may reflect differences in the response to severe vasodilation, provide novel insights into its biology, and predict clinical outcomes. The objective of these protocol prespecified and subsequent post hoc analyses was to assess the epidemiology and outcome associations of plasma ANG I and ANG II levels and their ratio in patients with catecholamine-resistant vasodilatory shock (CRVS) enrolled in the Angiotensin II for the Treatment of High-Output Shock (ATHOS-3) study. METHODS: We measured ANG I and ANG II levels at baseline, calculated their ratio, and compared these results to values from healthy volunteers (controls). We dichotomized patients according to the median ANG I/II ratio (1.63) and compared demographics, clinical characteristics, and clinical outcomes. We constructed a Cox proportional hazards model to test the independent association of ANG I, ANG II, and their ratio with clinical outcomes. RESULTS: Median baseline ANG I level (253 pg/mL [interquartile range (IQR) 72.30-676.00 pg/mL] vs 42 pg/mL [IQR 30.46-87.34 pg/mL] in controls; P <  0.0001) and median ANG I/II ratio (1.63 [IQR 0.98-5.25] vs 0.4 [IQR 0.28-0.64] in controls; P <  0.0001) were elevated, whereas median ANG II levels were similar (84 pg/mL [IQR 23.85-299.50 pg/mL] vs 97 pg/mL [IQR 35.27-181.01 pg/mL] in controls; P = 0.9895). At baseline, patients with a ratio above the median (≥1.63) had higher ANG I levels (P <  0.0001), lower ANG II levels (P <  0.0001), higher albumin concentrations (P = 0.007), and greater incidence of recent (within 1 week) exposure to angiotensin-converting enzyme inhibitors (P <  0.00001), and they received a higher norepinephrine-equivalent dose (P = 0.003). In the placebo group, a baseline ANG I/II ratio <1.63 was associated with improved survival (hazard ratio 0.56; 95% confidence interval 0.36-0.88; P = 0.01) on unadjusted analyses. CONCLUSIONS: Patients with CRVS have elevated ANG I levels and ANG I/II ratios compared with healthy controls. In such patients, a high ANG I/II ratio is associated with greater norepinephrine requirements and is an independent predictor of mortality, thus providing a biological rationale for interventions aimed at its correction. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT02338843. Registered 14 January 2015.

Circulating dipeptidyl peptidase-3 at admission is associated with circulatory failure, acute kidney injury and death in severely ill burn patients.

BACKGROUND: Dipeptidyl peptidase-3 (DPP3) is a metallopeptidase which cleaves bioactive peptides, notably angiotensin II, and is involved in inflammation regulation. DPP3 has been proposed to be a myocardial depressant factor and to be involved in circulatory failure in acute illnesses, possibly due to angiotensin II cleavage. In this study, we evaluated the association between plasmatic DPP3 level and outcome (mortality and hemodynamic failure) in severely ill burn patients. METHODS: In this biomarker analysis of a prospective cohort study, we included severely ill adult burn patients in two tertiary burn intensive care units. DPP3 was measured at admission (DPP3admin) and 3 days after. The primary endpoint was 90-day mortality. Secondary endpoints were hemodynamic failure and acute kidney injury (AKI). RESULTS: One hundred and eleven consecutive patients were enrolled. The median age was 48 (32.5-63) years, with a median total body surface area burned of 35% (25-53.5) and Abbreviated Burn Severity Index (ABSI) of 8 (7-11). Ninety-day mortality was 32%. The median DPP3admin was significantly higher in non-survivors versus survivors (53.3 ng/mL [IQR 28.8-103.5] versus 27.1 ng/mL [IQR 19.4-38.9]; p < 0.0001). Patients with a sustained elevated DPP3 had an increased risk of death compared to patients with high DPP3admin but decreased levels on day 3. Patients with circulatory failure had higher DPP3admin (39.2 ng/mL [IQR 25.9-76.1] versus 28.4 ng/mL [IQR 19.8-39.6]; p = 0.001) as well as patients with AKI (49.7 ng/mL [IQR 30.3-87.3] versus 27.6 ng/mL [IQR 19.4-41.4]; p = 0.001). DPP3admin added prognostic value on top of ABSI (added chi2 12.2, p = 0.0005), Sequential Organ Failure Assessment (SOFA) score at admission (added chi2 4.9, p = 0.0268), and plasma lactate at admission (added chi2 6.9, p = 0.0086) to predict circulatory failure within the first 48 h. CONCLUSIONS: Plasma DPP3 concentration at admission was associated with an increased risk of death, circulatory failure, and AKI in severely burned patients. Whether DPP3 plasma levels could identify patients who would respond to alternative hemodynamic support strategies, such as intravenous angiotensin II, should be explored.

Renin as a Marker of Tissue-Perfusion and Prognosis in Critically Ill Patients.

OBJECTIVES: To characterize renin in critically ill patients. Renin is fundamental to circulatory homeostasis and could be a useful marker of tissue-perfusion. However, diurnal variation, continuous renal replacement therapy and drug-interference could confound its use in critical care practice. DESIGN: Prospective observational study. SETTING: Single-center, mixed medical-surgical ICU in Europe. PATIENTS: Patients over 18 years old with a baseline estimated glomerular filtration rate greater than 30 mL/min/1.73 m and anticipated ICU stay greater than 24 hours. Informed consent was obtained from the patient or next-of-kin. INTERVENTIONS: Direct plasma renin was measured in samples drawn 6-hourly from arterial catheters in recumbent patients and from extracorporeal continuous renal replacement therapy circuits. Physiologic variables and use of drugs that act on the renin-angiotensin-aldosterone system were recorded prospectively. Routine lactate measurements were used for comparison. MEASUREMENTS AND MAIN RESULTS: One-hundred twelve arterial samples (n = 112) were drawn from 20 patients (65% male; mean ± SD, 60 ± 14 yr old) with septic shock (30%), hemorrhagic shock (15%), cardiogenic shock (20%), or no circulatory shock (35%). The ICU mortality rate was 30%. Renin correlated significantly with urine output (repeated-measures correlation coefficient = -0.29; p = 0.015) and mean arterial blood pressure (repeated-measures correlation coefficient = -0.35; p < 0.001). There was no diurnal variation of renin or significant interaction of renin-angiotensin-aldosterone system drugs with renin in this population. Continuous renal replacement therapy renin removal was negligible (mass clearance ± SD 4% ± 4.3%). There was a significant difference in the rate of change of renin over time between survivors and nonsurvivors (-32 ± 26 µU/timepoint vs +92 ± 57 µU/timepoint p = 0.03; mean ± SEM), but not for lactate (-0.14 ± 0.04 mM/timepoint vs +0.15 ± 0.21 mM/timepoint; p = 0.07). Maximum renin achieved significant prognostic value for ICU mortality (receiver operator curve area under the curve 0.80; p = 0.04), whereas maximum lactate did not (receiver operator curve area under the curve, 0.70; p = 0.17). CONCLUSIONS: In an heterogeneous ICU population, renin measurement was not significantly affected by diurnal variation, continuous renal replacement therapy, or drugs. Renin served as a marker of tissue-perfusion and outperformed lactate as a predictor of ICU mortality.

Plasma for burn shock resuscitation: is it time to go back to the future?

Patients with burn shock can be challenging to resuscitate. Burn shock produces a variety of physiologic derangements: Patients are hypovolemic from volume loss, have a increased systemic vascular resistance, and may have a depressed cardiac output depending on the extent of the thermal injury. Additionally, the burn wound produces a significant inflammatory cascade of events that contributes to the shock state. Fluid resuscitation is foundational for the initial treatment of burn shock. Typical resuscitation is with intravenous lactated Ringer's in accordance with well-established formulas based on burn wound size. In the past century, as therapies to treat thermal injuries were being developed, plasma was the fluid used for burn resuscitation; in fact, plasma was used in World War II and throughout the 1950s and 1960s. Plasma was abandoned because of infectious risks and complications. Despite huge strides in transfusion medicine and the increased safety of blood products, plasma has never been readopted for burn resuscitation. Over the past 15 years, there has been a paradigm shift in trauma resuscitation: Less crystalloid and more blood products are used; this strategy has demonstrated improved outcomes. Plasma is a physiologic fluid that stabilizes the endothelium. The endotheliopathy of trauma has been described and is mitigated by transfusion strategies with a 1:1 ratio of RBCs to plasma. Thermal injury also results in endothelial dysfunction: the endotheliopathy of burns. Plasma is likely a better resuscitation fluid for patients with significant burn wounds because of its capability to restore intravascular volume status and treat the endotheliopathy of burns.

Massive transfusion associated with a hemolytic transfusion reaction: necessary precautions for prevention.

CASE REPORT: A 45-year-old male presented in severe hypovolemic shock after a thoracoabdominal gunshot wound. The massive transfusion protocol (MTP) was activated and the patient was taken to the operating room. His major injuries included liver, small bowel, and right common iliac vein. Hemorrhage was stopped and a damage control laparotomy was completed. He received a total of 113 blood products. During his postoperative course he received a group B blood transfusion on Hospital Days 2 and 7 based on incorrect blood typing late in his massive transfusion and repeat testing on Day 4. RESULTS: He succumbed to multiple organ failure on Day 8. MTPs are standard in most trauma centers during which universal donor red blood cells are initially used. As hemorrhage is controlled, the patient undergoes a complete type and cross according to blood banking protocols. These typing results are used to continue transfusions once the MTP is no longer needed. In contacting other blood banks servicing Level I trauma centers, the policy of when to switch from universal donor blood to crossmatched blood is variable. CONCLUSION: Our case illustrates a potential blood typing problem that had a disastrous outcome. We identified changes in policy that will make MTPs safer.

The association between plasma miR-122-5p release pattern at admission and all-cause mortality or shock after out-of-hospital cardiac arrest.

BACKGROUND: Data suggests that the plasma levels of the liver-specific miR-122-5p might both be a marker of cardiogenic shock and a prognostic marker of out-of-hospital cardiac arrest (OHCA). Our aim was to characterize plasma miR-122-5p at admission after OHCA and to assess the association between miR-122-5p and relevant clinical factors such all-cause mortality and shock at admission after OHCA. METHODS: In the pilot trial, 10 survivors after OHCA were compared to 10 age- and sex-matched controls. In the main trial, 167 unconscious survivors of OHCA from the Targeted Temperature Management (TTM) trial were included. RESULTS: In the pilot trial, plasma miR-122-5p at admission after OHCA was 400-fold elevated compared to controls. In the main trial, plasma miR-122-5p at admission was independently associated with lactate and bystander cardiopulmonary resuscitation. miR-122-5p at admission was not associated with shock at admission (p = 0.14) or all-cause mortality (p = 0.35). Target temperature (33 °C vs 36 °C) was not associated with miR-122-5p levels at any time point. CONCLUSIONS: After OHCA, miR-122-5p demonstrated a marked acute increase in plasma and was independently associated with lactate and bystander resuscitation. However, miR-122-5p at admission was not associated with all-cause mortality or shock at admission.

Capillary refill time variation induced by passive leg raising predicts capillary refill time response to volume expansion.

BACKGROUND: A peripheral perfusion-targeted resuscitation during early septic shock has shown encouraging results. Capillary refill time, which has a prognostic value, was used. Adding accuracy and predictability on capillary refill time (CRT) measurement, if feasible, would benefit to peripheral perfusion-targeted resuscitation. We assessed whether a reduction of capillary refill time during passive leg raising (ΔCRT-PLR) predicted volume-induced peripheral perfusion improvement defined as a significant decrease of capillary refill time following volume expansion. METHODS: Thirty-four patients with acute circulatory failure were selected. Haemodynamic variables, metabolic variables (PCO2gap), and four capillary refill time measurements were recorded before and during a passive leg raising test and after a 500-mL volume expansion over 20 min. Receiver operating characteristic curves were built, and areas under the curves were calculated (ROCAUC). Confidence intervals (CI) were performed using a bootstrap analysis. We recorded mortality at day 90. RESULTS: The least significant change in the capillary refill time was 25% [95% CI, 18-30]. We defined CRT responders as patients showing a reduction of at least 25% of capillary refill time after volume expansion. A decrease of 27% in ΔCRT-PLR predicted peripheral perfusion improvement with a sensitivity of 87% [95% CI, 73-100] and a specificity of 100% [95% CI, 74-100]. The ROCAUC of ΔCRT-PLR was 0.94 [95% CI, 0.87-1.0]. The ROCAUC of baseline capillary refill time was 0.73 [95% CI, 0.54-0.90] and of baseline PCO2gap was 0.79 [0.61-0.93]. Capillary refill time was significantly longer in non-survivors than in survivors at day 90. CONCLUSION: ΔCRT-PLR predicted peripheral perfusion response following volume expansion. This simple low-cost and non-invasive diagnostic method could be used in peripheral perfusion-targeted resuscitation protocols. TRIAL REGISTRATION: CPP Lyon Sud-Est II ANSM: 2014-A01034-43 Clinicaltrial.gov, NCT02248025 , registered 13th of September 2014.

The effects of passive leg raising may be detected by the plethysmographic oxygen saturation signal in critically ill patients.

BACKGROUND: A passive leg raising (PLR) test is positive if the cardiac index (CI) increased by > 10%, but it requires a direct measurement of CI. On the oxygen saturation plethysmographic signal, the perfusion index (PI) is the ratio between the pulsatile and the non-pulsatile portions. We hypothesised that the changes in PI could predict a positive PLR test and thus preload responsiveness in a totally non-invasive way. METHODS: In patients with acute circulatory failure, we measured PI (Radical-7) and CI (PiCCO2) before and during a PLR test and, if decided, before and after volume expansion (500-mL saline). RESULTS: Three patients were excluded because the plethysmography signal was absent and 3 other ones because it was unstable. Eventually, 72 patients were analysed. In 34 patients with a positive PLR test (increase in CI ≥ 10%), CI and PI increased during PLR by 21 ± 10% and 54 ± 53%, respectively. In the 38 patients with a negative PLR test, PI did not significantly change during PLR. In 26 patients in whom volume expansion was performed, CI and PI increased by 28 ± 14% and 53 ± 63%, respectively. The correlation between the PI and CI changes for all interventions was significant (r = 0.64, p < 0.001). During the PLR test, if PI increased by > 9%, a positive response of CI (≥ 10%) was diagnosed with a sensitivity of 91 (76-98%) and a specificity of 79 (63-90%) (area under the receiver operating characteristics curve 0.89 (0.80-0.95), p < 0.0001). CONCLUSION: An increase in PI during PLR by 9% accurately detects a positive response of the PLR test. TRIAL REGISTRATION: ID RCB 2016-A00959-42. Registered 27 June 2016.

Low temperature increases capillary blood refill time following mechanical fingertip compression of healthy volunteers: prospective cohort study.

Capillary refill time has been accepted as a method to manually assess a patient's peripheral blood perfusion. Recently, temperature has been reported to affect capillary refill time and therefore temperature may interfere with accurate bedside peripheral blood perfusion evaluation. We applied a new method of analysis that uses standard hospital pulse oximetry equipment and measured blood refill time in order to test whether lowered fingertip temperature alters peripheral blood perfusion. Thirty adult healthy volunteers of differing races (skin colors) and age (young: 18-49 years and old: ≥ 50 years) groups were recruited. We created a high fidelity mechanical device to compress and release the fingertip and measure changes in blood volume using infrared light (940 nm). Capillary refill times were measured at the fingertip at three different temperature settings: ROOM TEMPERATURE, COLD by 15 °C cold water, and REWARM by 38 °C warm water. The COLD group has decreased fingertip temperature (23.6 ± 3.6 °C) and increased blood refill time (4.67 s [95% CI 3.57-5.76], p < 0.001). This was significantly longer than ROOM TEMPERATURE (1.96 [1.60-2.33]) and REWARM (1.96 [1.73-2.19]). Blood refill time in older subjects tended to be longer than in younger subjects (2.28 [1.61-2.94] vs. 1.65 [1.36-1.95], p = 0.077). There was a negative correlation (r = - 0.471, p = 0.009) between age and temperature. A generalized linear mixed-effects model revealed that lower temperature (OR 0.63 [95% CI 0.61-0.65], p < 0.001) rather than age (OR 1.00 [0.99-1.01], p = 0.395) was the independent factor most associated with increased blood refill time. Lowered fingertip temperatures significantly increase blood refill time which then returns to baseline when the fingertip is rewarmed. In our limited number of population, we did not find an association with age after the adjustment for the fingertip temperature.

Blood lactate concentration and shock index associated with massive transfusion in emergency department patients with primary postpartum haemorrhage.

BACKGROUND: We hypothesised that lactate concentrations are independently associated with massive transfusion in patients with primary postpartum haemorrhage. Moreover, combining lactate concentrations with the shock index, defined as the ratio of heart rate to systolic arterial blood pressure, can improve the predictive performance for massive transfusion. METHODS: We retrospectively analysed patients with primary postpartum haemorrhage in the emergency department of a tertiary referral centre in Korea between January 1, 2004 and December 31, 2015. RESULTS: Of the 302 patients, 101 (33.4%) patients required massive transfusion. Lactate concentration was independently associated with the requirement for massive transfusion [odds ratio, 1.56; 95% confidence interval (CI), 1.31-1.87; P<0.01]. The area under the receiver operating characteristic curve of lactate concentration and shock index for massive transfusion was 0.788 (95% CI: 0.736-0.840; P<0.01) and 0.776 (95% CI: 0.717-0.836; P<0.01), respectively. Lactate elevation (>4.0 mM L-1) was associated with 86.1% specificity and 67.8% positive predictive value for massive transfusion. When combining elevated lactate concentrations (>4.0 mM L-1) with a shock index >1.0, the specificity and positive predictive value increased to 95.5% and 82.4%, respectively. CONCLUSIONS: Point-of-care testing of lactate concentrations in the emergency department may be useful to predict massive transfusion requirements in primary postpartum haemorrhage. Combining initial lactate concentrations with the shock index improves the predictive performance for massive transfusion requirements and may contribute to rapid risk stratification of patients with primary postpartum haemorrhage in need of transfusion and further focus on early interventions to control bleeding.

Acute Kidney Injury as a Risk Factor for Delirium and Coma during Critical Illness.

RATIONALE: Acute kidney injury may contribute to distant organ dysfunction. Few studies have examined kidney injury as a risk factor for delirium and coma. OBJECTIVES: To examine whether acute kidney injury is associated with delirium and coma in critically ill adults. METHODS: In a prospective cohort study of intensive care unit patients with respiratory failure and/or shock, we examined the association between acute kidney injury and daily mental status using multinomial transition models adjusting for demographics, nonrenal organ failure, sepsis, prior mental status, and sedative exposure. Acute kidney injury was characterized daily using the difference between baseline and peak serum creatinine and staged according to Kidney Disease Improving Global Outcomes criteria. Mental status (normal vs. delirium vs. coma) was assessed daily with the Confusion Assessment Method for the ICU and Richmond Agitation-Sedation Scale. MEASUREMENTS AND MAIN RESULTS: Among 466 patients, stage 2 acute kidney injury was a risk factor for delirium (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.07-2.26) and coma (OR, 2.04; 95% CI, 1.25-3.34) as was stage 3 injury (OR for delirium, 2.56; 95% CI, 1.57-4.16) (OR for coma, 3.34; 95% CI, 1.85-6.03). Daily peak serum creatinine (adjusted for baseline) values were also associated with delirium (OR, 1.35; 95% CI, 1.18-1.55) and coma (OR, 1.44; 95% CI, 1.20-1.74). Renal replacement therapy modified the association between stage 3 acute kidney injury and daily peak serum creatinine and both delirium and coma. CONCLUSIONS: Acute kidney injury is a risk factor for delirium and coma during critical illness.

[Value of arterial blood lactic acid in the evaluation of disease severity and prognosis in neonatal shock].

OBJECTIVE: To evaluate the value of blood lactic acid (BLA) as a predictor for the severity and prognosis of neonatal shock. METHODS: A total of 326 neonates with shock were enrolled and divided into three groups based on the severity, namely mild group (n=147), moderate group (n=105), and severe group (n=74). BLA level was measured during and early after (about 6 hours later) fluid resuscitation, and lactate clearance rate (LCR) was calculated. The receiver operating characteristic (ROC) curve was applied to evaluate the predictive value of BLA in neonatal shock. RESULTS: BLA level was high in all subjects prior to treatment, and was highest in the severe group and lowest in the mild group (P<0.01). BLA level was significantly higher among patients with septic shock than among those with hypovolemic, cardiogenic, and asphyxiating shock (P<0.05). BLA level was significantly reduced in patients in recovery after treatment (P<0.05). Mortality was significantly lower in patients with BLA level ≤4 mmol/L or LCR ≥10% than in those with BLA level >4 mmol/L or LCR <10% (P<0.01). BLA at 11.15 mmol/L had 100% sensitivity and 96.8% specificity in predicting severe shock. BLA at 10.65 mmol/L had 88.9% sensitivity and 74.1% specificity in predicting the prognosis (survival or dead) of newborns with shock. CONCLUSIONS: In neonates with shock, arterial BLA level increases as the disease severity increases and is associated with prognosis, so it is a useful predictor of the severity and prognosis of neonatal shock.

Daily Lowest Hemoglobin and Risk of Organ Dysfunctions in Critically Ill Patients.

OBJECTIVES: To determine the association between hemoglobin levels and the daily risk of individual organ dysfunctions in critically ill patients. DESIGN: Post hoc analysis of prospectively collected data. SETTING: Vanderbilt University Medical Center and Saint Thomas Hospital Medical and Surgical ICUs. PATIENTS: Medical and surgical ICU patients admitted with respiratory failure or shock. INTERVENTIONS: Baseline demographic data, and detailed in-ICU and hospital data, including daily lowest hemoglobin, were collected up to hospital day 30. We assessed patients daily for brain dysfunction (delirium, using Confusion Assessment Method for ICU), for renal and respiratory dysfunction (using the ordinal renal and respiratory Sequential Organ Failure Assessment score), and for ICU mortality. Associations between the lowest hemoglobin on a given day and organ dysfunctions the following day were assessed using multivariable regressions, adjusting for age, Acute Physiology and Chronic Health Evaluation II score, Charlson comorbidity index, Framingham Stroke Risk Profile, ICU day, ICU type, sepsis, and current organ dysfunction status. A sensitivity analysis further adjusted for daily transfusions and fluid balance in a subset of our patients. MEASUREMENTS AND MAIN RESULTS: We enrolled 821 patients with a median (interquartile range) age of 61 (51-71) years, Acute Physiology and Chronic Health Evaluation II score of 25 (19-31), and hemoglobin level of 10.0 (9.0-11.1) g/dL. There was no evidence of an association between lowest daily hemoglobin and brain dysfunction (p = 0.69 for delirium), renal dysfunction (p = 0.30), or ICU mortality (p = 0.95). The lowest hemoglobin on a given day was significantly associated with the respiratory Sequential Organ Failure Assessment score the following day; for each increasing hemoglobin unit, the odds of worsened respiratory Sequential Organ Failure Assessment score the following day were decreased by 36% (OR, 0.64; 95% CI, 0.53-0.77; p < 0.001). The sensitivity analysis including daily transfusions and fluid balance (in a subset of 518 patients) did not qualitatively change any of these associations. CONCLUSIONS: In this study in ICU patients, lower hemoglobin was associated with a higher probability of worsening respiratory dysfunction scores the following day. There was no evidence of association between hemoglobin and brain or renal dysfunction, or ICU mortality. The possible differential effects of anemia on organ dysfunctions seen in this hypothesis-generating study will have to be studied in a larger prospective study before any alterations to present restrictive transfusion guidelines can be recommended.

Lactate and microcirculation as suitable targets for hemodynamic optimization in resuscitation of circulatory shock.

PURPOSE OF REVIEW: A discussion of recent research exploring the feasibility of perfusion-guided resuscitation of acute circulatory failure with a focus on lactate and microcirculation. RECENT FINDINGS: Upon diagnosis of shock, hyperlactemia is associated with poor outcome and, under appropriate clinical circumstances, may reflect inadequate tissue perfusion. Persistent hyperlactemia despite resuscitation is even more strongly correlated with morbidity and mortality. Importantly, there is minimal coherence between lactate trends and static hemodynamic measures such as blood pressure, especially after the initial, hypovolemic phase of shock. During this early period, lactate guided-resuscitation is effective and possibly superior to hemodynamic-guided resuscitation. Similar to hyperlactemia, impaired microcirculation is ubiquitous in shock and is evident even in the setting of hemodynamic compensation (i.e., occult shock). Moreover, persistent microcirculatory derangement is associated with poor outcome and may reflect ongoing shock and/or long-lasting damage. Although the wait continues for a microcirculation-guided resuscitation trial, there is progress toward this goal. SUMMARY: Although questions remain, a multimodal perfusion-based approach to resuscitation is emerging with lactate and microcirculation as core measures. In this model, hyperlactemia and microcirculatory derangement support the diagnosis of shock, may help guide resuscitation during the initial period, and may reflect resuscitation efficacy and iatrogenic harm (e.g., fluid overload).