Hemodynamic monitoring in shock and implications for management. International Consensus Conference, Paris, France, 27-28 April 2006

Comparison of Noninvasive Oscillometric and Intra-Arterial Blood Pressure Measurements in Children Admitted to the Pediatric Intensive Care Unit

Intra-arterial blood pressure (IABP) measurement, although considered the gold standard in critically ill children, is associated with certain risks and lacks widespread availability. This study was conducted to determine the differences and agreements between oscillometric non-invasive blood pressure (NIBP) and invasive IABP measurements in children. Inclusion criteria consisted of children (from 1 month to 18 years) admitted to the pediatric intensive care unit (PICU) of a teaching hospital who required arterial catheter insertion for blood pressure (BP) monitoring. The comparison between IABP and NIBP was studied using paired t -test, Bland-Altman analysis, and Pearson's correlation coefficient. In total, 4,447 pairs of simultaneously recorded hourly NIBP and IABP measurements were collected from 65 children. Mean differences between IABP and NIBP were -3.6 ± 12.85, -4.7 ± 9.3, and -3.12 ± 9.30 mm Hg for systolic, diastolic, and mean arterial BP, respectively ( p  < 0.001), with wide limits of agreement. NIBP significantly overestimated BP ( p  < 0.001) in all three BP states (hypotensive, normotensive, and hypertensive), except systolic blood pressure (SBP) during hypertension where IABP was significantly higher. The difference in SBP was most pronounced during hypotension. The difference in SBP was significant in children <10 years ( p  < 0.001), with the maximum difference being in infants. It was insignificant in adolescents ( p  = 0.28) and underweight children ( p  = 0.55). NIBP recorded significantly higher BP in all states of BP except SBP in the hypertensive state. SBP measured by NIBP tended to be the most reliable in adolescents and underweight children. NIBP was the most unreliable in infants, obese children, and during hypotension.

Utility of NICaS Non-Invasive Hemodynamic Monitoring in Critically Ill Patients with COVID-19

(1) Background: COVID-19 presented many challenges to effective treatments, such as managing cardiovascular insufficiency while mitigating risks to healthcare providers. This study utilized NICaS, a non-invasive hemodynamic monitor that provides advanced data via whole-body impedance analysis. We investigated the associated trends in hemodynamic parameters obtained by the NICaS device and their correlation with in-hospital all-cause mortality during COVID-19 hospitalization in the intensive care unit. (2) Methods: Data from 29 patients with COVID-19 admitted to the intensive care unit and monitored with NICaS between April 2020 and February 2021 were analyzed retrospectively. (3) Results: Decreasing cardiac output and cardiac power were significantly associated with death. Total peripheral resistance was significantly increasing in non-survivors as was total body water percentage. Those admitted with a heart rate above 90 beats per minute had a significantly reduced survival. (4) Conclusions: Non-invasive hemodynamic monitoring via the NICaS device is simple and effective in evaluating critically ill patients with COVID-19 and may help guide clinical management via remote monitoring. Controlling tachycardia may help ensure adequate oxygen supply-demand ratio. A hint toward a beneficiary effect of a restrictive fluid balance may be observed.

Determinants of acute kidney injury during high-power mechanical ventilation: secondary analysis from experimental data

BACKGROUND

The individual components of mechanical ventilation may have distinct effects on kidney perfusion and on the risk of developing acute kidney injury; we aimed to explore ventilatory predictors of acute kidney failure and the hemodynamic changes consequent to experimental high-power mechanical ventilation.

METHODS

Secondary analysis of two animal studies focused on the outcomes of different mechanical power settings, including 78 pigs mechanically ventilated with high mechanical power for 48 h. The animals were categorized in four groups in accordance with the RIFLE criteria for acute kidney injury (AKI), using the end-experimental creatinine: (1) NO AKI: no increase in creatinine; (2) RIFLE 1-Risk: increase of creatinine of > 50%; (3) RIFLE 2-Injury: two-fold increase of creatinine; (4) RIFLE 3-Failure: three-fold increase of creatinine; RESULTS: The main ventilatory parameter associated with AKI was the positive end-expiratory pressure (PEEP) component of mechanical power. At 30 min from the initiation of high mechanical power ventilation, the heart rate and the pulmonary artery pressure progressively increased from group NO AKI to group RIFLE 3. At 48 h, the hemodynamic variables associated with AKI were the heart rate, cardiac output, mean perfusion pressure (the difference between mean arterial and central venous pressures) and central venous pressure. Linear regression and receiving operator characteristic analyses showed that PEEP-induced changes in mean perfusion pressure (mainly due to an increase in CVP) had the strongest association with AKI.

CONCLUSIONS

In an experimental setting of ventilation with high mechanical power, higher PEEP had the strongest association with AKI. The most likely physiological determinant of AKI was an increase of pleural pressure and CVP with reduced mean perfusion pressure. These changes resulted from PEEP per se and from increase in fluid administration to compensate for hemodynamic impairment consequent to high PEEP.

Role of point of care ultrasound in the absence of radial pulse and unrecordable blood pressure during the assessment of shock: Case report

INTRODUCTION

Point-of-care ultrasound (POCUS) has been an integral part of patient evaluation in the Emergency Department. It has been used increasingly for the evaluation of critically ill and trauma patients.

CASE PRESENTATION

We report a case of 60-year-old male patient who presented to the Emergency department with flank pain and urinary symptoms suggesting pyelonephritis with unrecordable blood pressure indicating potential septic shock, but the absence of bilateral radial pulses triggered the use of POCUS which reveal bilateral radial artery occlusion.

CASE DISCUSSION

Assessment of the peripheral pulses (usually radial pulse) is an important clue to estimate the systolic blood pressure with presence of a pulse correlating to a systolic SBP of ≥80 mmHg. this case report showed there was an absent peripheral radial and brachial pulse despite the patient appearing hemodynamically stable and no other signs of shock. By utilizing vascular POCUS, the patient's diagnosis completely changed. The use of POCUS led to an instant diagnosis and appropriate patient management.

CONCLUSION

Point-of-Care ultrasound is a valuable diagnostic tool that can help narrow down differential diagnostics and guide early proper management and intervention.

Pheochromocytoma-induced cardiogenic shock: A multicentre analysis of clinical profiles, management and outcomes

OBJECTIVE

There is still uncertainty about the management of patients with pheochromocytoma-induced cardiogenic shock (PICS). This study aims to investigate the clinical presentation, management, and outcome of patients with PICS.

METHODS

We collected, retrospectively, the data of 18 patients without previously known pheochromocytoma admitted to 8 European hospitals with a diagnosis of PICS.

RESULTS

Among the 18 patients with a median age of 50 years (Q1-Q3: 40-61), 50% were men. The main clinical features at presentation were pulmonary congestion (83%) and cyclic fluctuation of hypertension peaks and hypotension (72%). Echocardiography showed a median left ventricular ejection fraction (LVEF) of 25% (Q1-Q3: 15-33.5) with an atypical- Takotsubo (TTS) pattern in 50%. Inotropes/vasopressors were started in all patients and temporary mechanical circulatory support (t-MCS) was required in 11 (61%) patients. All patients underwent surgical removal of the pheochromocytoma; 4 patients (22%) were operated on while under t-MCS. The median LVEF was estimated at 55% at discharge. Only one patient required heart transplantation (5.5%), and all patients were alive at a median follow-up of 679 days.

CONCLUSIONS

PICS should be suspected in case of a CS with severe cyclic blood pressure fluctuation and rapid hemodynamic deterioration, associated with increased inflammatory markers or in case of TTS progressing to CS, particularly if an atypical TTS echocardiographic pattern is revealed. T-MCS should be considered in the most severe cases. The main challenge is to stabilize the patient, with medical therapy or with t-MCS, since it remains a reversible cause of CS with a low mortality rate.

Volume Management with Kidney Replacement Therapy in the Critically Ill Patient

While the administration of intravenous fluids remains an important treatment, the negative consequences of subsequent fluid overload have raised questions about when and how clinicians should pursue avenues of fluid removal. Decisions regarding fluid removal during critical illness are complex even for patients with preserved kidney function. This article seeks to apply general concepts of fluid management to the care of patients who also require KRT. Because optimal fluid management for any specific patient is likely to change over the course of critical illness, conceptual models using phases of care have been developed. In this review, we will examine the implications of one such model on the use of ultrafiltration during KRT for volume removal in distributive shock. This will also provide a useful lens to re-examine published data of KRT during critical illness. We will highlight recent prospective trials of KRT as well as recent retrospective studies examining ultrafiltration rate and mortality, review the results, and discuss applications and shortcomings of these studies. We also emphasize that current data and techniques suggest that optimal guidelines will not consist of recommendations for or against absolute fluid removal rates but will instead require the development of dynamic protocols involving frequent cycles of reassessment and adjustment of net fluid removal goals. If optimal fluid management is dynamic, then frequent assessment of fluid responsiveness, fluid toxicity, and tolerance of fluid removal will be needed. Innovations in our ability to assess these parameters may improve our management of ultrafiltration in the future.

Arterial cannulation in adult critical care patients: A comparative study between ultrasound guidance and palpation technique

OBJECTIVE

To compare first attempt success rate for ultrasound-guided (USG) versus direct palpation (DP) for radial, femoral, and dorsalis pedis artery cannulations in adult intensive care unit (ICU) patients.

DESIGN

Prospective randomized clinical trial.

SETTING

Mixed adult ICU of a University Hospital.

PARTICIPANTS

Adult patients (≥18 years) admitted to the ICU requiring invasive arterial pressure monitoring were included. Exclusion criteria were patients with a pre-existing arterial line and cannulated with other than a 20-gauge cannula for radial and dorsalis pedis artery.

INTERVENTION

Comparison of arterial cannulation by USG versus palpation technique in radial, femoral and dorsalis pedis arteries.

MAIN VARIABLES OF INTEREST

Primary outcome was first attempt success rate, secondary outcomes were assessing time for cannulations, number of attempts, overall success rate, complications, and comparison of two techniques on patients requiring vasopressor.

RESULTS

201 patients were enrolled in study, with 99 randomized to DP group and 102 to USG group. Arteries (radial, dorsalis pedis, femoral) cannulated in both groups were comparable (P = .193). Arterial line was placed on first attempt in 85 (83.3%) in USG group versus 55 (55.6%) in DP group (P = .02). Cannulation time in USG group was significantly shorter compared to DP group.

CONCLUSIONS

In our study, USG arterial cannulation, compared to palpatory technique, had a higher success rate at first attempt and a shorter cannulation time.

CLINICAL TRIAL REGISTRY OF INDIA NUMBER

CTRI/2020/01/022989.

The effect of short-course point-of-care echocardiography training on the performance of medical interns in children

BACKGROUND

Point-of-care ultrasound (POCUS) can add complementary information to physical examination. Despite its development in several medical specialties, there is a lack of similar studies on children by medical interns and cardiologists. Therefore, investigators aimed to assess the effect of short-course training on the performance of medical interns in point-of-care echocardiography in children.

METHODS

This analytic cross-sectional study was conducted on 161 hospitalized children in 17 Shahrivar children's hospital, Iran, from January 2021 to May 2021. Seven interns (trainees) participated in a short course of point-of-care echocardiography to assess left ventricular ejection fraction (LVEF), inferior vena cava collapsibility index (IVCCI), and the presence of pericardial effusion (PEff). Each patient underwent point-of-care echocardiography by one of the trainees. Then, in less than one hour, the echocardiography was performed by a single cardiologist. Agreement between the cardiologist and trainees was examined using Cohen's kappa coefficient and Prevalence-Adjusted Bias-Adjusted Kappa (PABAK). For numerical variables, the agreement was examined using the concordance correlation coefficient (CCC) and intraclass correlation coefficient (ICC).

RESULTS

Results showed that the cardiologist and trainees detected LVEF >50, IVCCI >50%, and the absence of PEff in most of the participants. A good agreement in terms of ICC and CCC for LVEF (0.832 and 0.831, respectively) and a good agreement in terms of ICC and CCC for IVCCI (0.878 and 0.877, respectively) were noted. Using categorical scoring of LVEF and IVCCI showed 94.4% and 87.6% complete agreement, respectively. Furthermore, using categorical scoring of LVEF and IVCCI, Cohen's kappa coefficient was 0.542 (moderate) and 0.619 (substantial), respectively. The PABAK for LVEF and IVCCI were 0.886 (almost perfect) and 0.752 (substantial), respectively. For PEff, Cohen's kappa and PABAK were 0.797 (moderate) and 0.988 (almost perfect), respectively, and the complete agreement was noted in 160 patients (99.4%).

CONCLUSIONS

This study showed that a short teaching course could help medical interns to assess LVEF, IVCCI, and PEff in children. Therefore, it seems that adding this course to medical interns' curricula can be promising.

Methylene blue dosing strategies in critically ill adults with shock-A retrospective cohort study

Background

Shock increases mortality in the critically ill and the mainstay of therapy is the administration of vasopressor agents to achieve hemodynamic targets. In the past, studies have found that the NO-pathway antagonist methylene blue improves hemodynamics. However, the optimal dosing strategy remains elusive. Therefore, we investigated the hemodynamic and ICU outcome parameters of three different dosing strategies for methylene blue.

Methods

We performed a retrospective cohort study of patients in shock treated with methylene blue. Shock was defined as norepinephrine dose >0.1 μg/kg/min and serum lactate level >2 mmol/l at the start of methylene blue administration. Different demographic variables, ICU treatment, and outcome parameters were evaluated. To compare the differences in the administration of vasopressors or inotropes, the vasoactive inotropic score (VIS) was calculated at different time points after starting the administration of methylene blue. Response to methylene blue or mortality at 28 days were assessed.

Results

262 patients from July 2014 to October 2019 received methylene blue. 209 patients met the inclusion criteria. Three different dosing strategies were identified: bolus injection followed by continuous infusion (n = 111), bolus injection only (no continuous infusion; n = 59) or continuous infusion only (no bolus prior; n = 39). The groups did not differ in demographics, ICU scoring system, or comorbidities. In all groups, VIS decreased over time, indicating improved hemodynamics. Cardiogenic shock and higher doses of norepinephrine increased the chance of responding to methylene blue, while bolus only decreased the chance of responding to methylene blue treatment. 28-day mortality increased with higher SAPSII scores and higher serum lactate levels, while bolus injection followed by continuous infusion decreased 28-day mortality. No severe side effects were noted.

Conclusion

In this cohort, methylene blue as a bolus injection followed by continuous infusion was associated with a reduced 28-day mortality in patients with shock. Prospective studies are needed to systematically evaluate the role of methylene blue in the treatment of shock.

Timing errors and temporal uncertainty in clinical databases-A narrative review

A firm concept of time is essential for establishing causality in a clinical setting. Review of critical incidents and generation of study hypotheses require a robust understanding of the sequence of events but conducting such work can be problematic when timestamps are recorded by independent and unsynchronized clocks. Most clinical models implicitly assume that timestamps have been measured accurately and precisely, but this custom will need to be re-evaluated if our algorithms and models are to make meaningful use of higher frequency physiological data sources. In this narrative review we explore factors that can result in timestamps being erroneously recorded in a clinical setting, with particular focus on systems that may be present in a critical care unit. We discuss how clocks, medical devices, data storage systems, algorithmic effects, human factors, and other external systems may affect the accuracy and precision of recorded timestamps. The concept of temporal uncertainty is introduced, and a holistic approach to timing accuracy, precision, and uncertainty is proposed. This quantitative approach to modeling temporal uncertainty provides a basis to achieve enhanced model generalizability and improved analytical outcomes.

Malnutrition-Inflammation Liaison in Predicting AKI following OPCABG in Diabetics: Role of a Novel Monocyte/High-Density Lipoprotein × Albumin Ratio

Background Monocyte/high-density lipoprotein ratio (MHR) has been recently proposed as a parsimonious inflammatory marker. Akin to MHR, hypoalbuminemia (a malnutrition marker) has a considerable proinflammatory potential and confers an accentuated risk of postcardiac surgery complications, like acute kidney injury (AKI). The present study evaluated the AKI-predictive value of the preoperative monocyte/high-density lipoprotein × albumin ratio (MHAR) in diabetic patients undergoing off-pump coronary artery bypass grafting (OPCABG).

Methods The retrospective study conducted at our tertiary cardiac care center included 687 diabetic OPCABG patients. Forty-eight hours postoperative data was evaluated for the occurrence of AKI, as defined by the Acute Kidney Injury Network criteria. The perioperative attributes of the AKI and non-AKI groups were compared to evaluate the predictors of AKI, by employing a regression analysis.

Results A total of 109 patients (15.87%) developed AKI postoperatively. On univariate analysis: age, EuroSCORE II, preoperative congestive heart failure, systemic hypertension, serum albumin, MHR, MHAR, intraoperative packed red blood cell transfusion, postoperative low cardiac output syndrome, and vasoactive-inotropic score (VIS) predicted AKI. AKI subsequent to multivariate analysis, age (odds ratio [OR]: 1.029), EuroSCORE II (OR: 1.264), MHAR (OR: 1.403), and VIS (OR: 1.07) were the independent predictors (p-values: 0.020, < 0.001, 0.013, 0.002, respectively). The AKI predictive cutoffs of albumin, MHR, and MHAR were ≤ 2.95, ≥ 15.25, and ≥ 4.08 (area under the curve:sensitivity:specificity of 0.761:84.86%:89.62%; 0.754:93.12%:86.68%; 0.798:89.63%:88.34%, respectively). MHAR ≥ 4.08 was also associated with a higher incidence of postoperative atrial fibrillation and major adverse cardiac events.

Conclusion Preoperative elevated MHAR independently predicts AKI following OPCABG in diabetics, implying a malnutrition-inflammation liaison at heart of the matter.

Association between central haemodynamics and renal function in advanced heart failure: a nationwide study from Sweden

AIMS

Renal dysfunction in patients with heart failure (HF) has traditionally been attributed to declining cardiac output and renal hypoperfusion. However, other central haemodynamic aberrations may contribute to impaired kidney function. This study assessed the relationship between invasive central haemodynamic measurements from right-heart catheterizations and measured glomerular filtration rate (mGFR) in advanced HF.

METHODS AND RESULTS

All patients referred for heart transplantation work-up in Sweden between 1988 and 2019 were identified through the Scandiatransplant organ-exchange organization database. Invasive haemodynamic variables and mGFR were retrieved retrospectively. A total of 1001 subjects (49 ± 13 years; 24% female) were eligible for the study. Analysis of covariance adjusted for age, sex, and centre revealed that higher right atrial pressure (RAP) displayed the strongest relationship with impaired GFR [β coefficient -0.59; 95% confidence interval (CI) -0.69 to -0.48; P < 0.001], followed by lower mean arterial pressure (MAP) (β coefficient 0.29; 95% CI 0.14-0.37; P < 0.001), and finally reduced cardiac index (β coefficient 3.51; 95% CI 2.14-4.84; P < 0.003). A combination of high RAP and low MAP was associated with markedly worse mGFR than any other RAP/MAP profile, and high renal perfusion pressure (RPP, MAP minus RAP) was associated with superior renal function irrespective of the degree of cardiac output.

CONCLUSIONS

In patients with advanced HF, high RAP contributed more to impaired GFR than low MAP. A higher RPP was more closely related to GFR than was high cardiac index.

Sex-dependent jugular vein optical attenuation and distension during head-down tilt and lower body negative pressure

Non‐contact coded hemodynamic imaging (CHI) is a novel wide‐field near‐infrared spectroscopy system which monitors blood volume by quantifying attenuation of light passing through the underlying vessels. This study tested the hypothesis that CHI‐based jugular venous attenuation (JVA) would be larger in men, and change in JVA would be greater in men compared to women during two fluid shift challenges. The association of JVA with ultrasound‐based cross‐sectional area (CSA) was also tested. Ten men and 10 women completed three levels of head‐down tilt (HDT) and four levels of lower body negative pressure (LBNP). Both JVA and CSA were increased by HDT and reduced by LBNP (all p < 0.001). Main effects of sex indicated that JVA was higher in men than women during both HDT (p = 0.003) and LBNP (p = 0.011). Interaction effects of sex and condition were observed for JVA during HDT (p = 0.005) and LBNP (p < 0.001). We observed moderate repeated‐measures correlations (r_rm) between JVA and CSA in women during HDT (r_rm = 0.57, p = 0.011) and in both men (r_rm = 0.74, p < 0.001) and women (r_rm = 0.66, p < 0.001) during LBNP. While median within‐person correlation coefficients indicated an even stronger association between JVA and CSA, this association became unreliable for small changes in CSA. As hypothesized, JVA was greater and changed more in men compared to women during both HDT and LBNP. CHI provides a non‐contact method of tracking large changes in internal jugular vein blood volume that occur with acute fluid shifts, but data should be interpreted in a sex‐dependent manner.

Blood Pressure in Critically Ill Children: Exploratory Analyses of Concurrent Invasive and Noninvasive Measurements

Supplemental Digital Content is available in the text.

OBJECTIVES:

Differences and biases between directly measured intra-arterial blood pressure and intermittingly measured noninvasive blood pressure using an oscillometric cuff method have been reported in adults and children. At the bedside, clinicians are required to assign a confidence to a specific blood pressure measurement before acting upon it, and this is challenging when there is discordance between measurement techniques. We hypothesized that big data could define and quantify the relationship between noninvasive blood pressure and intra-arterial blood pressure measurements and how they can be influenced by patient characteristics, thereby aiding bedside decision-making.

DESIGN:

A retrospective analysis of cuff blood pressure readings with associated concurrent invasive arterial blood pressure measurements (452,195 noninvasive blood pressure measurements).

SETTING:

Critical care unit at The Hospital for Sick Children, Toronto.

PATIENTS:

Six-thousand two-hundred ninety-seven patients less than or equal to 18 years old, hospitalized in a critical care unit with an indwelling arterial line.

INTERVENTIONS:

None.

MEASUREMENTS AND MAIN RESULTS:

Two-dimensional distributions of intra-arterial blood pressure and noninvasive blood pressure were generated and the conditional distributions of intra-arterial blood pressure examined as a function of the noninvasive systolic, diastolic, or mean blood pressure. Modification of these distributions according to age and gender were examined using a multilevel mixed-effects model. For any given combination of patient age and noninvasive blood pressure, the expected distribution of intra-arterial blood pressure readings exhibited marked variability at the population level and a bias that significantly depended on the noninvasive blood pressure value and age. We developed an online tool that allows exploration of the relationship between noninvasive blood pressure and intra-arterial blood pressure and the conditional probability distributions according to age.

CONCLUSIONS:

A large physiologic dataset provides clinically applicable insights into the relationship between noninvasive blood pressure and intra-arterial blood pressure measurements that can help guide decision-making at the patient bedside.

The Pathophysiology and Management of Hemorrhagic Shock in the Polytrauma Patient

The recognition and management of life-threatening hemorrhage in the polytrauma patient poses several challenges to prehospital rescue personnel and hospital providers. First, identification of acute blood loss and the magnitude of lost volume after torso injury may not be readily apparent in the field. Because of the expression of highly effective physiological mechanisms that compensate for a sudden decrease in circulatory volume, a polytrauma patient with a significant blood loss may appear normal during examination by first responders. Consequently, for every polytrauma victim with a significant mechanism of injury we assume substantial blood loss has occurred and life-threatening hemorrhage is progressing until we can prove the contrary. Second, a decision to begin damage control resuscitation (DCR), a costly, highly complex, and potentially dangerous intervention must often be reached with little time and without sufficient clinical information about the intended recipient. Whether to begin DCR in the prehospital phase remains controversial. Furthermore, DCR executed imperfectly has the potential to worsen serious derangements including acidosis, coagulopathy, and profound homeostatic imbalances that DCR is designed to correct. Additionally, transfusion of large amounts of homologous blood during DCR potentially disrupts immune and inflammatory systems, which may induce severe systemic autoinflammatory disease in the aftermath of DCR. Third, controversy remains over the composition of components that are transfused during DCR. For practical reasons, unmatched liquid plasma or freeze-dried plasma is transfused now more commonly than ABO-matched fresh frozen plasma. Low-titer type O whole blood may prove safer than red cell components, although maintaining an inventory of whole blood for possible massive transfusion during DCR creates significant challenges for blood banks. Lastly, as the primary principle of management of life-threatening hemorrhage is surgical or angiographic control of bleeding, DCR must not eclipse these definitive interventions.

Quality of Death in Fighting Bulls during Bullfights: Neurobiology and Physiological Responses

During bullfights, bulls undergo physiometabolic responses such as glycolysis, anaerobic reactions, cellular oedema, splenic contraction, and hypovolemic shock. The objective of this review article is to present the current knowledge on the factors that cause stress in fighting bulls during bullfights, including their dying process, by discussing the neurobiology and their physiological responses. The literature shows that biochemical imbalances occur during bullfights, including hypercalcaemia, hypermagnesaemia, hyperphosphataemia, hyperlactataemia, and hyperglycaemia, associated with increased endogenous cortisol and catecholamine levels. Creatine kinase, citrate synthase, and lactate dehydrogenase levels also increase, coupled with decreases in pH, blood bicarbonate levels, excess base, partial oxygen pressure, and oxygen saturation. The intense exercise also causes a marked decrease of glycogen in type I and II muscle fibres that can produce myoglobinuria and muscular necrosis. Other observations suggest the presence of osteochondrosis. The existing information allows us to conclude that during bullfights, bulls face energy and metabolic demands due to the high intensity and duration of the exercise performed, together with muscular injuries, physiological changes, and high enzyme concentrations. In addition, the final stage of the bullfight causes a slow dying process for an animal that is sentient and conscious of its surroundings.

Neutrophil Gelatinase-associated Lipocalin Predicts Post-traumatic Acute Kidney Injury in Severely Injured Patients

BACKGROUND

Early detection of acute kidney injury (AKI) is crucial in the management of multiple-organ dysfunction syndrome in severely injured patients. Standard laboratory parameters usually increase with temporal delay. Therefore, we evaluated neutrophil gelatinase-associated lipocalin (NGAL) as an early marker for acute kidney injury.

PATIENTS AND METHODS

We retrospectively evaluated patients admitted to a level 1 trauma center. We collected clinicodemographic data and measured kidney-related factors and plasma cytokines.

RESULTS

A total of 39 patients were included. Patients with AKI had significantly higher levels not only of serum creatinine and urea, but also of NGAL (all p<0.001) than patients without AKI. The optimal NGAL cut-off value was determined to be 177 ng/ml, showing significant correlation with imminent or manifest AKI (p<0.001). Other independent markers correlated with AKI included pre-existing chronic kidney disease, use of catecholamines, and severe injury (p<0.001).

CONCLUSION

The serum level of NGAL is feasible early predictor of AKI.

Extremity trauma exacerbates acute kidney injury following prolonged hemorrhagic hypotension

BACKGROUND

The incidence of and mortality due to acute kidney injury is high in patients with traumatic shock. However, it is unclear how hemorrhage and trauma synergistically affect renal function, especially when timely volume resuscitation is not available.

METHOD

We hypothesized that trauma impairs renal tolerance to prolonged hemorrhagic hypotension. Sprague-Dawley rats were randomized into six groups: control, extremity trauma (ET), hemorrhage at 70 mm Hg (70-H), hemorrhage at 55 mm Hg (55-H), ET + 70 mm Hg (70-ETH), and ET + 55 mm Hg (55-ETH). Animals were anesthetized, and ET was induced via soft tissue injury and closed fibula fracture. Hemorrhage was performed via catheters 5 minutes after ET with target mean arterial pressure (MAP) clamped at 70 mm Hg or 55 mm Hg for up to 3 hours. Blood and urine samples were collected to analyze plasma creatinine (Cr), Cr clearance (CCr), renal oxygen delivery (DO2), urinary albumin, and kidney injury molecule-1 (KIM-1).

RESULTS

Extremity trauma alone did not alter renal hemodynamics, DO2, or function. In 70-H, CCr was increased following hemorrhage, while Cr, renal vascular resistance (RVR), KIM-1, and albumin levels remained unchanged. Compared with 70-H, ET + 70 mm Hg exhibited increases in Cr and RVR with decreases in CCr and DO2. In addition, ET decreased the blood volume loss required to maintain MAP = 70 mm Hg by approximately 50%. Hemorrhage at 55 mm Hg and ET + 55 mm Hg exhibited a marked and similar decrease in CCr and increases in RVR, Cr, KIM-1, and albumin. However, ET greatly decreased the blood volume loss required to maintain MAP at 55 mm Hg and led to 50% mortality.

CONCLUSION

These results suggest that ET impairs renal and systemic tolerance to prolonged hemorrhagic hypotension. Thus, traumatic injury should be considered as a critical component of experimental studies investigating outcomes and treatment following hemorrhagic shock.

LEVEL OF EVIDENCE

This is an original article on basic science and does not require a level of evidence.

Early Lactate-Guided Resuscitation of Elderly Septic Patients

BACKGROUND

Early lactate-guided resuscitation was endorsed in the guidelines of the Surviving Sepsis Campaign as a key strategy to decrease the mortality of patients admitted to the ICU department with septic shock. However, its effectiveness in elderly Asian patients is uncertain.

METHOD

We conducted a single-center trial to test the effectiveness of the early lactate-guided resuscitation of older Asian patients at the Second Hospital of Hebei Medical University. Eligible septic shock patients who consented to participation in the study were randomly assigned to receive early lactate-guided treatment or regular treatment as controls.

RESULT

A total of 82 patients met the hyperlactatemia criteria and participated in the trial. Forty-two patients received early lactate-guided treatment (lactate group) and 40 received regular treatment (control group). The lactate group received more fluids at initial 6 hours (3.3 ± 1.4 vs 2.4 ± 1.7 L, P = 0.01), but similar proportions of patients in both groups required the use of vasopressors and vasodilators. Patients in the lactate group showed significantly reduced ICU needs compared to the control group, which were weaned from mechanical ventilation more quickly (median 7, IQR 4 to 14 vs median 9, IQR 4.3 to 17.8, P = 0.02) and transferred out of the ICU earlier (median 4.5, IQR 2.8 to 7.3 vs median 6, IQR 3.2 to 8, P = 0.01). However, the hospital mortality (35.7% vs 42.5%, P = 0.35) and ICU mortality (31.0% vs 37.5%, P = 0.38) for both groups were not reduced.

CONCLUSION

For critically ill patients (elderly Asian patients) admitted to the ICU department with hyperlactatemia, early lactate-guided treatment reduced ICU needs but did not reduce mortality.

Brain death and management of the potential donor

One of the first attempts to define brain death (BD) dates from 1963, and since then, the diagnosis criteria of that entity have evolved. In spite of the publication of practice parameters and evidence-based guidelines, BD is still causing concern and controversies in the society. The difficulties in determining brain death and making it understood by family members not only endorse futile therapies and increase health care costs, but also hinder the organ transplantation process. This review aims to give an overview about the definition of BD, causes, physiopathology, diagnosis criteria, and management of the potential brain-dead donor. It is important to note that the BD determination criteria detailed here follow the AAN’s recommendations, but the standard practice for BD diagnosis varies from one country to another.

Doppler Echocardiographic Indices Are Specific But Not Sensitive to Predict Pulmonary Artery Occlusion Pressure in Critically Ill Patients Under Mechanical Ventilation

OBJECTIVES

The objective of this study was to prospectively evaluate the ability of transthoracic echocardiography to assess pulmonary artery occlusion pressure in mechanically ventilated critically ill patients.

DESIGN

In a prospective observational study.

SETTING

Amiens University Hospital Medical ICU.

PATIENTS

Fifty-three mechanically ventilated patients in sinus rhythm admitted to our ICU.

INTERVENTION

Transthoracic echocardiography was performed simultaneously to pulmonary artery catheter.

MEASUREMENTS AND MAIN RESULTS

Transmitral early velocity wave recorded using pulsed wave Doppler (E), late transmitral velocity wave recorded using pulsed wave Doppler (A), and deceleration time of E wave were recorded using pulsed Doppler as well as early mitral annulus velocity wave recorded using tissue Doppler imaging (E'). Pulmonary artery occlusion pressure was measured simultaneously using pulmonary artery catheter. There was a significant correlation between pulmonary artery occlusion pressure and lateral ratio between E wave and E' (E/E' ratio) (r = 0.35; p < 0.01), ratio between E wave and A wave (E/A ratio) (r = 0.41; p < 0.002), and deceleration time of E wave (r = -0.34; p < 0.02). E/E' greater than 15 was predictive of pulmonary artery occlusion pressure greater than or equal to 18 mm Hg with a sensitivity of 25% and a specificity of 95%, whereas E/E' less than 7 was predictive of pulmonary artery occlusion pressure less than 18 mm Hg with a sensitivity of 32% and a specificity of 81%. E/A greater than 1.8 yielded a sensitivity of 44% and a specificity of 95% to predict pulmonary artery occlusion pressure greater than or equal to 18 mm Hg, whereas E/A less than 0.7 was predictive of pulmonary artery occlusion pressure less than 18 mm Hg with a sensitivity of 19% and a specificity of 94%. A similar predictive capacity was observed when the analysis was confined to patients with EF less than 50%. A large proportion of E/E' measurements 32 (60%) were situated between the two cut-off values obtained by the receiver operating characteristic curves: E/E' greater than 15 and E/E' less than 7.

CONCLUSIONS

In mechanically ventilated critically ill patients, Doppler transthoracic echocardiography indices are highly specific but not sensitive to estimate pulmonary artery occlusion pressure.

Assessment of Volume Status and Fluid Responsiveness in Small Animals

Intravenous fluids are an essential component of shock management in human and veterinary emergency and critical care to increase cardiac output and improve tissue perfusion. Unfortunately, there are very few evidence-based guidelines to help direct fluid therapy in the clinical setting. Giving insufficient fluids and/or administering fluids too slowly to hypotensive patients with hypovolemia can contribute to continued hypoperfusion and increased morbidity and mortality. Similarly, giving excessive fluids to a volume unresponsive patient can contribute to volume overload and can equally increase morbidity and mortality. Therefore, assessing a patient's volume status and fluid responsiveness, and monitoring patient's response to fluid administration is critical in maintaining the balance between meeting a patient's fluid needs vs. contributing to complications of volume overload. This article will focus on the physiology behind fluid responsiveness and the methodologies used to estimate volume status and fluid responsiveness in the clinical setting.

Changes in perfusion can detect changes in the cardiac index in patients with septic shock

Objective

The perfusion index (PI) is usually used to assess peripheral perfusion, which can be influenced by the cardiac index (CI). CI monitoring is often needed during the treatment of patients with shock. We investigated the relationship between changes in the PI (ΔPI) and changes in the CI (ΔCI) in patients with septic shock.

Methods

This retrospective study included patients with septic shock who underwent pulse-induced continuous cardiac output monitoring. We measured the CI and PI before and after fluid loading during the first 6 hours of intensive care unit admission. Fluid responsiveness was defined as a ≥10% ΔCI after fluid loading. Other hemodynamic and oxygen-derived parameters were also collected at the exact time of each CI measurement.

Results

Fifty-five patients were included in the study (29 fluid responders, 26 fluid non-responders). In the univariate analysis, ΔPI was positively correlated with ΔCI. In the multivariable analysis, ΔPI was independently associated with ΔCI. The receiver operating characteristic curve showed that ΔPI was an appropriate marker with which to discriminate a CI increase with an area under the curve of 0.776.

Conclusion

This study showed a positive correlation between ΔPI and ΔCI during the early treatment phase of septic shock.

Can Coagulation System Disorders and Cytokine and Inflammatory Marker Levels Predict the Temporary Clinical Deterioration or Improvement of Septic Patients on ICU Admission?

Although coagulation disorders and immune/inflammatory response have been associated with the final outcome of patients with sepsis, their link with thetemporaryclinical deterioration or improvement of patients is unknown. We aimed to investigate this link. We prospectively included consecutive patients admitted to the intensive care unit (ICU) with a suspected diagnosis of infection and evaluated within the first 24 h from admission. Blood levels of many cytokines and inflammatory and coagulation factors were measured and their predictive value was assessed by calculating the Area Under the Receiver Operating Characteristic (AUROC) curves. Patients (n = 102) were allocated in five groups, i.e., sepsis (n = 14), severe sepsis (n = 17), septic shock (n = 28), Systemic Inflammatory Response Syndrome (SIRS) without infection (n = 17), and trauma/surgery without SIRS or infection (n = 26). In septic shock, coagulation factors FVII and FIX and Protein C had AUROCs 0.67-0.78. In severe sepsis, Antithrombin III, Protein C, C-reactive protein, Procalcitonin and Thrombopoietin had AUROCs 0.73-0.75. In sepsis, Tumor Necrosis Factor a, and Interleukins 1β and 10 had AUROCs 0.66-0.72. In patients admitted to the ICU with a suspected diagnosis of infection, coagulation factors and inhibitors, as well as cytokine and inflammatory marker levels, have substantial predictive value in distinct groups of septic patients.

A Critical Review of Hemodynamically Guided Therapy for Cardiogenic Shock: Old Habits Die Hard

Purpose of review

Here, we review the importance of using hemodynamic data to guide therapy and risk stratification in cardiogenic shock as well as the various definitions of this syndrome that have been used in prior studies. Furthermore, we provide perspective regarding the controversy surrounding pulmonary artery (PA) catheter use as well as current society guidelines and scientific statements. Lastly, we review the technical aspects for accurate interpretation of data of cardiogenic shock.

Recent findings

More recent studies specifically evaluating cardiogenic shock patients have shown higher mortality when PA catheters were not used. Furthermore, initiatives are underway to develop more standardized definitions of cardiogenic shock, including the SCAI Shock Classification Scheme. Only by having a standardized fashion of conveying severity of shock will we be able to more systematically study this patient population and improve outcomes moving forward.

Summary

PA catheters are critical to the prognostication and management of a subset of patients with cardiopulmonary disease, particularly in those with pulmonary hypertension, cardiogenic shock, or requiring mechanical circulatory support or undergoing evaluation for advanced heart failure therapies.

Prolonged Capillary Refilling as a Predictor of Mortality in Patients With Septic Shock

INTRODUCTION

Microcirculatory alterations characterize septic shock; increased blood lactate level has been described as markers of microcirculation alteration in patients with septic shock. Although useful, this serological analysis is not always feasible in all settings worldwide.

OBJECTIVE

To determine if a prolonged capillary refilling is a predictor of mortality in patients with septic shock.

METHODOLOGY

A 10-months prospective cohort study was carried out on 175 patients admitted to the Intensive Care Unit (ICU) with the diagnosis of septic shock. The capillary refilling time (CRT) was evaluated Immediately upon admission and after 6 hours post-resuscitation. Traditional tissue perfusion markers were also used to compare and analyze their predictive value on mortality at 28 days.

RESULTS

The area under the ROC curve (AUC) to estimate mortality in patients with septic shock with CRT at admission was 0.666 (0.584-0.748), while at 6 hours was 0.819 (0.753-0.885), with a cut-off point of 4.5 seconds at admission (PPV 52.87% NPV 72.73%) and 3.5 sec at 6 hours (PPV 95.56% NPV 79.23%). In those with CRT > 3.5 seconds at 6 hours, they had a RR of 4.60, while a CRT > 4.5 seconds at admission had a RR of 1.94, with a non-survivor proportion of 95.56% for a CRT > 3.5 sec at 6 hours vs 20.77% for CRT ≤ 3.5 sec (P value < 0.001). The CRT at 6 hours showed significant differences in the survival curves with P-value < 0.001, where for values > 3.5 sec, survival at 28 days was 4.44% vs 79.20% for values ≤ 3.5 sec.

CONCLUSION

CRT is a strong predictor of mortality in patients with septic shock. Evaluating changes in CRT during resuscitation from septic shock might be used as an important clinical tool to predict mortality; especially in low-resources settings where using other biomarkers might be sometimes difficult.

Error grid analysis for risk management in the difference between invasive and noninvasive blood pressure measurements

PURPOSE

Invasive arterial blood pressure (IAP) and noninvasive blood pressure (NIBP) measurements are both common methods. Recently, a new method of error grid analysis was proposed to compare blood pressure obtained using two measurement methods. This study aimed to compare IAP and NIBP measurements using the error grid analysis and investigate potential confounding factors affecting the discrepancies between IAP and NIBP.

METHODS

Adult patients who underwent general anesthesia in the supine position with both IAP and NIBP measurements were retrospectively investigated. The error grid analyses were performed to compare IAP and NIBP. In the error grid analysis, the clinical relevance of the discrepancies between IAP and NIBP was evaluated and classified into five zones from no risk (A) to dangerous risk (E).

RESULTS

Overall, data of 1934 IAP/NIBP measurement pairs from 100 patients were collected. The error grid analysis revealed that the proportions of zones A-E for systolic blood pressure were 96.4%, 3.5%, 0.05%, 0%, and 0%, respectively. In contrast, the proportions for mean blood pressure were 82.5%, 16.7%, 0.8%, 0%, and 0%, respectively. The multiple regression analysis revealed that continuous phenylephrine administration (p = 0.016) and age (p = 0.044) were the significant factors of an increased clinical risk of the differences in mean blood pressure.

CONCLUSIONS

The error grid analysis indicated that the differences between IAP and NIBP for mean blood pressure were not clinically acceptable and had the risk of leading to unnecessary treatments. Continuous phenylephrine administration and age were the significant factors of an increased clinical risk of the discrepancies between IAP and NIBP.

Management of pharmaceutical and recreational drug poisoning

BACKGROUND

Poisoning is one of the leading causes of admission to the emergency department and intensive care unit. A large number of epidemiological changes have occurred over the last years such as the exponential growth of new synthetic psychoactive substances. Major progress has also been made in analytical screening and assays, enabling the clinicians to rapidly obtain a definite diagnosis.

METHODS

A committee composed of 30 experts from five scientific societies, the Société de Réanimation de Langue Française (SRLF), the Société Française de Médecine d'Urgence (SFMU), the Société de Toxicologie Clinique (STC), the Société Française de Toxicologie Analytique (SFTA) and the Groupe Francophone de Réanimation et d'Urgences Pédiatriques (GFRUP) evaluated eight fields: (1) severity assessment and initial triage; (2) diagnostic approach and role of toxicological analyses; (3) supportive care; (4) decontamination; (5) elimination enhancement; (6) place of antidotes; (7) specificities related to recreational drug poisoning; and (8) characteristics of cardiotoxicant poisoning. Population, Intervention, Comparison, and Outcome (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. Analysis of the literature and formulation of recommendations were then conducted according to the GRADE® methodology.

RESULTS

The SRLF-SFMU guideline panel provided 41 statements concerning the management of pharmaceutical and recreational drug poisoning. Ethanol and chemical poisoning were excluded from the scope of these recommendations. After two rounds of discussion and various amendments, a strong consensus was reached for all recommendations. Six of these recommendations had a high level of evidence (GRADE 1±) and six had a low level of evidence (GRADE 2±). Twenty-nine recommendations were in the form of expert opinion recommendations due to the low evidences in the literature.

CONCLUSIONS

The experts reached a substantial consensus for several strong recommendations for optimal management of pharmaceutical and recreational drug poisoning, mainly regarding the conditions and effectiveness of naloxone and N-acetylcystein as antidotes to treat opioid and acetaminophen poisoning, respectively.

Recommendations for hemodynamic monitoring for critically ill children-expert consensus statement issued by the cardiovascular dynamics section of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC)

BACKGROUND

Cardiovascular instability is common in critically ill children. There is a scarcity of published high-quality studies to develop meaningful evidence-based hemodynamic monitoring guidelines and hence, with the exception of management of shock, currently there are no published guidelines for hemodynamic monitoring in children. The European Society of Paediatric and Neonatal Intensive Care (ESPNIC) Cardiovascular Dynamics section aimed to provide expert consensus recommendations on hemodynamic monitoring in critically ill children.

METHODS

Creation of a panel of experts in cardiovascular hemodynamic assessment and hemodynamic monitoring and review of relevant literature-a literature search was performed, and recommendations were developed through discussions managed following a Quaker-based consensus technique and evaluating appropriateness using a modified blind RAND/UCLA voting method. The AGREE statement was followed to prepare this document.

RESULTS

Of 100 suggested recommendations across 12 subgroups concerning hemodynamic monitoring in critically ill children, 72 reached "strong agreement," 20 "weak agreement," and 2 had "no agreement." Six statements were considered as redundant after rephrasing of statements following the first round of voting. The agreed 72 recommendations were then coalesced into 36 detailing four key areas of hemodynamic monitoring in the main manuscript. Due to a lack of published evidence to develop evidence-based guidelines, most of the recommendations are based upon expert consensus.

CONCLUSIONS

These expert consensus-based recommendations may be used to guide clinical practice for hemodynamic monitoring in critically ill children, and they may serve as a basis for highlighting gaps in the knowledge base to guide further research in hemodynamic monitoring.

Continuous cardiac output assessment or serial echocardiography during septic shock resuscitation?

Septic shock is the leading cause of cardiovascular failure in the intensive care unit (ICU). Cardiac output is a primary component of global oxygen delivery to organs and a sensitive parameter of cardiovascular failure. Any mismatch between oxygen delivery and rapidly varying metabolic demand may result in tissue dysoxia, hence organ dysfunction. Since the intricate alterations of both vascular and cardiac function may rapidly and widely change over time, cardiac output should be measured repeatedly to characterize the type of shock, select the appropriate therapeutic intervention, and evaluate patient's response to therapy. Among the numerous techniques commercially available for measuring cardiac output, transpulmonary thermodilution (TPT) provides a continuous monitoring with external calibration capability, whereas critical care echocardiography (CCE) offers serial hemodynamic assessments. CCE allows early identification of potential sources of inaccuracy of TPT, including right ventricular failure, severe tricuspid or left-sided regurgitations, intracardiac shunt, very low flow states, or dynamic left ventricular outflow tract obstruction. In addition, CCE has the unique advantage of depicting the distinct components generating left ventricular stroke volume (large cavity size vs. preserved contractility), providing information on left ventricular diastolic properties and filling pressures, and assessing pulmonary artery pressure. Since inotropes may have deleterious effects if misused, their initiation should be based on the documentation of a cardiac dysfunction at the origin of the low flow state by CCE. Experts widely advocate using CCE as a first-line modality to initially evaluate the hemodynamic profile associated with shock, as opposed to more invasive techniques. Repeated assessments of both the efficacy (amplitude of the positive response) and tolerance (absence of side-effect) of therapeutic interventions are required to best guide patient management. Overall, TPT allowing continuous tracking of cardiac output variations and CCE appear complementary rather than mutually exclusive in patients with septic shock who require advanced hemodynamic monitoring.

Lactated Ringer's Versus 4% Albumin on Lactated Ringer's in Early Sepsis Therapy in Cancer Patients: A Pilot Single-Center Randomized Trial

OBJECTIVE

To investigate the effects of the administration of 4% albumin on lactated Ringer's, when compared with lactated Ringer's alone, in the early phase of sepsis in cancer patients.

DESIGN

Single-center, randomized, double-blind, controlled-parallel trial.

SETTING

A tertiary care university cancer hospital.

PATIENTS

Cancer patients with severe sepsis or septic shock.

INTERVENTIONS

Between October 2014 and December 2016, patients were randomly assigned to receive either bolus of albumin in a lactated Ringer's solution or lactated Ringer's solution alone during the first 6 hours of fluid resuscitation after intensive care medicine (ICU) admission. Primary outcome was defined as death from any cause at 7 days. Secondary outcomes were defined as death from any cause within 28 days, change in Sequence Organ Failure Assessment scores from baseline to day 7, days alive and free of mechanical ventilation, days alive and free of vasopressor, renal replacement therapy during ICU stay, and length of ICU and hospital stay.

MEASUREMENTS AND MAIN RESULTS

A total of 360 patients were enrolled in the trial. At 7 days, 46 of 180 patients (26%) died in the albumin group and 40 of 180 (22%) died in the lactated Ringer's group (p = 0.5). At 28 days, 96 of 180 patients (53%) died in the albumin group and 83 of 180 (46%) died in the lactated Ringer's group (p = 0.2). No significant differences in secondary outcomes were observed.

CONCLUSIONS

Adding albumin to early standard resuscitation with lactated Ringer's in cancer patients with sepsis did not improve 7-day survival.

Value of Hemodynamic Monitoring in Patients With Cardiogenic Shock Undergoing Mechanical Circulatory Support

The recent widespread availability and use of mechanical circulatory support is transforming the management and outcomes of cardiogenic shock (CS). Clinical decision-making regarding the optimization of therapies for patients with CS can be guided effectively by hemodynamic monitoring with a pulmonary artery catheter (PAC). Because several studies regarding the benefit of PACs are ambiguous, the use of PACs is variable among clinicians treating patients with CS. More notable is that PAC use has not been studied as part of a randomized, controlled trial in patients with CS with or without mechanical circulatory support. Standardized approaches to hemodynamic monitoring in these patients can improve decision-making and outcomes. In this review, we summarize the hemodynamics of CS and mechanical circulatory support with PAC-derived measurements, and provide a compelling rationale for the use of PAC monitoring in patients with CS receiving mechanical circulatory support.

Blood lactate and lactate kinetics as treatment and prognosis markers for tissue hypoperfusion

Objective: Blood lactate concentration (L) and lactate kinetic (LK) over time might be a helpful marker of the shock severity. The purpose of this study is to analyze whether the L and LK could correlate with the outcome and the therapy of patients with different types of shock.Methods: Design: A 3.5-year retrospective observational study. Patients: Eighteen years of age or older, diagnosed with shock were included. Arterial L measurements were performed upon admission and approximatively 3 and 6 h later. The evolution of lactate over this period of time was correlated with the outcome and therapy. Interventions: Univariate and multivariable statistical tests were performed to examine the relation between the initial L/LK and the in-hospital mortality, total mortality, length of stay (LOS), the LOS at the intensive care unit and the administered therapy. The optimal cut-off point of the LK over time to predict the mortality was calculated.Results: The initial L and the 6 h LK were significantly associated with the outcome. The higher the initial L and lower the LK, the higher the risk of mortality in the hospital or within 6 months. Moreover, the higher the initial L and lower the 6 h LK, the longer was the LOS. A relation between the initial L/LK and the required therapy was found. The optimal cut-off for the 6-h LK is 38.1%. Patients with a 6 h LK >38.1% had a significantly higher chance of survival.Conclusions: A significant relationship between the L/6-h LK and the outcome and treatment was found. The optimal survival cut-off point of 6 h LK in our study was 38.1%.

Is dynamic arterial elastance a predictor of an increase in blood pressure after fluid administration in pediatric patients with hypotension? Reanalysis of prospective observational studies

BACKGROUND

Dynamic arterial elastance (Ea_dyn ) has been proposed to predict an increase in mean arterial pressure (MAP) after volume expansion in hypotensive adults. We aimed to evaluate the clinical usefulness of Ea_dyn as a predictor of arterial pressure response after fluid loading in pediatric patients with hypotension.

METHODS

We re-analyzed data of 63 hypotensive children (age, ≤5 years), collected from three previous prospective observational studies about fluid responsiveness. Pulse pressure variation (PPV), stroke volume variation (SVV), and respiratory variation in aortic blood flow velocity (ΔVpeak) were used to calculate Ea_dyn (PPV/SVV) and modified Ea_dyn (PPV/ΔVpeak). Preload-dependent patients were defined as those with ΔVpeak ≥12% before fluid loading. Patients were classified as pressure responders, if their MAP increased ≥15% after fluid administration.

RESULTS

Mean Ea_dyn (SD) was 1.06 (0.47) in pressure responders (n=39) and 0.99 (0.48) in nonresponders (n = 24) (mean difference, 0.08; 95% confidence interval [CI], -0.19-0.34; P = .567). Additionally, mean modified Ea_dyn was 1.27 (0.64) in responders and 1.11 (0.43) in nonresponders (mean difference, 0.17; 95% CI, -0.13-0.46; P = 0.269). Both Ea_dyn (AUC 0.506; 95% confidence interval [CI], 0.337 to 0.675; P = 0.948) and modified Ea_dyn (AUC 0.498; 95% CI, 0.328-0.669; P = 0.983), as well as other dynamic variables, could not predict pressure responsiveness in children. Sub-group analysis revealed similar findings in both in 39 preload-dependent and hypotensive patients (26 pressure responders and 13 nonpressure responders).

CONCLUSION

Both Ea_dyn and modified Ea_dyn cannot predict whether blood pressure increases with fluid administration in pediatric patients with hypotension.

Non-Invasive Venous waveform Analysis (NIVA) for monitoring blood loss in human blood donors and validation in a porcine hemorrhage model

STUDY OBJECTIVE

There is an unmet need for a non-invasive approach to diagnose hemorrhage early, before changes in vital signs occur. Non-Invasive Venous waveform Analysis (NIVA) uses a unique physiological signal (the peripheral venous waveform) to assess intravascular volume. We hypothesized changes in the venous waveform would be observed with blood loss in healthy adult blood donors and characterized hemorrhage using invasive monitoring in a porcine model.

DESIGN

Prospective observational study.

SETTING

American Red Cross donation center.

PATIENTS

50 human blood donors and 12 non-donating controls; 7 Yorkshire pigs.

INTERVENTIONS

A venous waveform capturing prototype (NIVA device) was secured to the volar aspect of the wrist in human subjects. A central venous catheter was used to obtain hemodynamic indices and venous waveforms were obtained using the prototype NIVA device over the saphenous vein during 400 mL of graded hemorrhage in a porcine model.

MEASUREMENTS

Venous waveforms were transformed from the time to the frequency domain. The ratiometric power contributions of the cardiac frequencies were used to calculate a NIVA value representative of volume status.

MAIN RESULTS

A significant decrease in NIVA value was observed after 500 mL of whole blood donation (p < .05). A ROC curve for the ability of the NIVA to detect 500 mL of blood loss demonstrated an area under the curve (AUC) of 0.94. In the porcine model, change in NIVA value correlated linearly with blood loss and with changes in hemodynamic indices.

CONCLUSIONS

This study provides proof-of-concept for a potential application of NIVA in detection of blood loss. NIVA represents a novel physiologic signal for detection of early blood loss that may be useful in early triage and perioperative management.

Renal resistive index: a new reversible tool for the early diagnosis and evaluation of organ perfusion in critically ill patients: a case report

BACKGROUND

We reported a case of early detection of peripheral hypoperfusion trough the evaluation of a new index in intensive care: Renal Doppler Resistive Index (RRI).

CASE PRESENTATION

We admitted a 76-year-old man who underwent ileostomy and hernioplasty because of an intestinal occlusion due to obstructive strangulated right inguinal hernia. The post-operative period was characterised by hemodynamic instability and he needed an invasive hemodynamic monitoring, administration of vasopressors and continuous renal replacement therapy (CRRT). Then, hemodynamic stability was obtained and vasopressors interrupted. RRI was lower than 0.7. In the eleventh post-operative day, despite stable macrocirculatory parameters, we found increased values of RRI. An abdomen ultrasound first and then a CT scan revealed the presence of bleeding from the previous ileostomy. Hence, the patient immediately underwent another surgical operation.

CONCLUSIONS

RRI modification appears to be more precocious than any other hemodynamic, microcirculatory and metabolic parameter routinely used. RRI has been widely used to assess renal function in critically ill patients; now, we presume that RRI could represent a common and useful tool to manage target therapy in critical condition.

Evaluation and management of elevated blood pressures in hospitalized children

Elevated blood pressures (BP) are common among hospitalized children and, if not recognized and treated promptly, can lead to potentially significant consequences. Even though we have normative BP data and well-developed guidelines for the diagnosis and management of hypertension (HTN) in the ambulatory setting, our understanding of elevated BPs and their relationship to HTN in hospitalized children is limited. Several issues have hampered our ability to diagnose and manage HTN in the inpatient setting including the common presence of physiologic conditions, which are associated with transient BP elevations (i.e., pain or anxiety), non-standard approaches to BP measurement, a lack of clarity regarding appropriate diagnostic and therapeutic thresholds, and marginal outcome data. The purpose of this review is to highlight the issues and challenges surrounding BP monitoring, assessment of elevated BPs, and the diagnosis of HTN in hospitalized children. Extrapolating from currently available clinical practice guidelines and utilizing the best data available, we aim to provide guidelines regarding evaluation and treatment of elevated BP in hospitalized children.

Predictive significance of tissue hypoperfusion markers in different shock types in low income countries

The most common condition that brings patients to the medical intensive care unit (MICU) is hemodynamic instability, accompanied by tissue hypoperfusion. In order to make easier and quicker diagnosis of this syndrome marker tissue hypoperfusion is monitored. The aim of this study is to determine the prognostic significance of the level of lactate, lactate clearance, central venous oxygen saturation (ScvO₂) and venous-to-arterial carbon dioxide difference (∆pCO₂) in two time periods in critically ill patients with acute circulatory failure in low income countries. This is a prospective study for a period of 8 months that included all patients with signs of cardiovascular system failure and tissue hypoperfusion. The study included 82 patients with the mean age of 64 years, of which 37% were women. The values of the lactate in surviving patients who had some form of non-septic shock at the zero hour (T₀) were T₀ = 6.31 ± 5.15, and at the sixth hour after reanimation the values (T₆) were T₆ = 3.71 ± 3.62 (p < 0.05), while the lactate levels in the group of non-survivors were T₀ = 6.64 ± 7.55 and T₆ = 9.41 ± 9.51; (p > 0.05). The main conclusion of this study is that the serum lactate concentration in patients who developed some form of non-septic shock has the highest predictive significance compared to the other two markers of tissue hypoperfusion (venous-to-arterial carbon dioxide difference and central venous oxygen saturation).

The use of bedside echocardiography for measuring cardiac index and systemic vascular resistance in pediatric patients with septic shock

Objective

Follow-up of cardiac index and systemic vascular resistance index by bedside echocardiography until resuscitation.

Methods

A set of hemodynamic parameters was obtained, including cardiac output, stroke volume, cardiac index, systemic vascular resistance index, velocity time integral, myocardial performance index, capillary refill time, and heart rate at 0 hours after fluid boluses before the start of inotropes, and followed up after 6 hours and 24 hours.

Results

Included were 45 patients with community-acquired septic shock. Septic foci were gastroenteritis (24%), intestinal perforation requiring emergency surgery (24%), pneumonia (20%), central nervous system infection (22%) and soft tissue infection (8%). Klebsiella and Enterobacter were the most frequent isolates. We estimated the factors affecting the cardiac index: high central venous pressure at zero time (r = 0.33, p = 0.024) and persistently high heart rate at hour 6 (r = 0.33, p = 0.03). The systemic vascular resistance index was high in most patients at 0 and 24 hours and at the time of resuscitation and inversely affected the cardiac index as well as affecting the velocity time integral (r = -0.416, -0.61, 0.55 and -0.295). Prolonged capillary refill time was a clinical predictor of the low velocity time integral at 24 hours (r = -0.4). The mortality was 27%. Lower systemic vascular resistance index and higher cardiac output were observed in nonsurviving patients.

Conclusion

There was a persistently high systemic vascular resistance index in cold shock patients that influenced the stroke volume index, cardiac index, and velocity time integral. The use of echocardiograms for hemodynamic measurements is important in pediatric septic shock patients to adjust dilators, and vasopressor doses and achieve resuscitation targets in a timely manner.

Effect of Systolic Cardiac Function on Passive Leg Raising for Predicting Fluid Responsiveness: A Prospective Observational Study

BACKGROUND

Passive leg raising (PLR) represents a "self-volume expansion (VE)" that could predict fluid responsiveness, but the influence of systolic cardiac function on PLR has seldom been reported. This study aimed to investigate whether systolic cardiac function, estimated by the global ejection fraction (GEF) from transpulmonary-thermodilution, could influence the diagnostic value of PLR.

METHODS

This prospective, observational study was carried out in the surgical Intensive Care Unit of the First Affiliated Hospital of Sun Yat-sen University from December 2013 to July 2015. Seventy-eight mechanically ventilated patients considered for VE were prospectively included and divided into a low-GEF (<20%) and a near-normal-GEF (≥20%) group. Within each group, baseline hemodynamics, after PLR and after VE (250 ml 5% albumin over 30 min), were recorded. PLR-induced hemodynamic changes (PLR-Δ) were calculated. Fluid responders were defined by a 15% increase of stroke volume (SV) after VE.

RESULTS

Twenty-five out of 38 patients were responders in the GEF <20% group, compared to 26 out of 40 patients in the GEF ≥20% group. The thresholds of PLR-ΔSV and PLR-Δ cardiac output (PLR-ΔCO) for predicting fluid responsiveness were higher in the GEF ≥20% group than in the GEF <20% group (ΔSV: 12% vs. 8%; ΔCO: 7% vs. 6%), with increased sensitivity (ΔSV: 92% vs. 92%; ΔCO: 81% vs. 80%) and specificity (ΔSV: 86% vs. 70%; ΔCO: 86% vs. 77%), respectively. PLR-Δ heart rate could predict fluid responsiveness in the GEF ≥20% group with a threshold value of -5% (sensitivity 65%, specificity 93%) but could not in the GEF <20% group. The pressure index changes were poor predictors.

CONCLUSIONS

In the critically ill patients on mechanical ventilation, the diagnostic value of PLR for predicting fluid responsiveness depends on cardiac systolic function. Thus, cardiac systolic function must be considered when using PLR.

TRIAL REGISTRATION

Chinese Clinical Trial Register, ChiCTR-OCH-13004027; http://www.chictr.org.cn/showproj.aspx?proj=5540.

Lung injury prediction scores: Clinical validation and C-reactive protein involvement in high risk patients

OBJECTIVE

A study was made to validate two previously derived lung injury prediction scores (LIPS) for the prediction of acute respiratory distress syndrome (ARDS) in high risk intensive care patients, with the incorporation of C-reactive protein (CRP) for improving score accuracy.

DESIGN

A prospective, observational cohort study was carried out.

PATIENTS

A total of 200 patients with APACHE II score ≥15 and at least one ARDS risk factor upon ICU admission were included.

INTERVENTIONS

Calculation of LIPS using formulas developed by Cartin-Ceba et al. (2009) and Trillo-Alvarez et al. (2011) (LIPS-2009 and LIPS-2011). C-reactive protein was measured upon admission (CRP-0) and after 48h (CRP-48).

MAIN VARIABLES OF INTEREST

Independent variables: LIPS-2009, LIPS-2011 and CRP values. Dependent variable: development of ARDS.

RESULTS

Eighty-eight patients (44%) developed ARDS after a median (Q₁-Q₃) of 2.5 (1.3-6.8) days. The LIPS-2009 and LIPS-2011 scores were 4 (3-6) and 5 (3.6-6.5) in ARDS patients compared to 2 (1-4) and 3.5 (1.5-4.5) in non-ARDS patients (p<0.001). CRP-48 was 96 (67.5-150.3)mg/L and 48 (24-96)mg/L in the two groups, respectively (p<0.001). ΔCRP (i.e., CRP-48 minus CRP-0) was significantly higher in the ARDS patients (p<0.001). The AUC was 0.740 and 0.738 for LIPS-2011 and LIPS-2009, respectively - the difference being nonsignificant (p=0.9, 0.9 and 0.8 for pairwise comparison of the different ROC curves). Integrating ΔCRP with LIPS-2011 using binary logistic regression analysis identified a new score (LIPS-N) with AUC 0.803, which was significantly higher than the AUC of LIPS-2011 (p=0.01).

CONCLUSIONS

Both LIPS scores are equally effective in predicting ARDS in high risk ICU patients. Integrating the change in CRP within the score might improve its accuracy.

[Prognostic value of difference between peripheral venous and arterial partial pressure of carbon dioxide in patients with septic shock: a pilot study]

OBJECTIVE

To evaluate the prognostic value of the difference between peripheral venous and arterial partial pressure of carbon dioxide in patients with septic shock following early resuscitation.

METHODS

This prospective study was conducted among the patients with septic shock treated in our department during the period from May, 2017 to May, 2018. Peripheral venous, peripheral arterial and central venous blood samples were collected simultaneously and analyzed immediately at bedside after 6-h bundle treatment. Arterial blood lactate concentration (Lac) and the arterial (PaCO₂), peripheral venous (PpvCO₂) and central venous partial pressure of carbon dioxide (PcvCO₂) were recorded. The differences between PpvCO₂ and PaCO₂ (Ppv-aCO₂) and between PcvCO₂ and PaCO₂ (Pcv-aCO₂) were calculated. Pearson correlation analysis was used to test the agreement between Pcv-aCO₂ and Ppv-aCO₂. Multivariable logistic regression analysis was performed to analyze the possible risk factors for 28-day mortality, and the receiver-operating characteristic curve (ROC) was plotted to assess the prognostic values of these factors for 28-day mortality.

RESULTS

A total of 62 patients were enrolled in this study, among who 35 survived and 27 died during the 28-day period. Compared with the survivor group, the patients died within 28 days showed significantly higher Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score (24.2±6.0 vs 20.5±4.9, P=0.011), sequential organ failure assessment (SOFA) score (14.9±4.7 vs 12.2±4.5, P=0.027), PcvaCO₂ (5.5±1.6 vs 7.1±1.7, P &lt; 0.001), PpvaCO₂ (7.1±1.8 vs 10.0±2.7, P &lt; 0.001), and arterial lactate level (3.3±1.2 vs 4.2±1.3, P=0.003) after 6-h bundle treatment. Pearson correlation analysis showed that Ppv-aCO₂ was significantly correlated with Pcv-aCO₂ (r=0.897, R²= 0.805, P &lt; 0.001). Multiple logistic regression analysis identified Ppv-aCO₂ (β=0.625, P=0.001, OR=1.869, 95% CI: 1.311-2.664) and lactate level (β=0.584, P=0.041, OR=1.794, 95%CI: 1.024-3.415) as the independent risk factors for 28-day mortality. The maximum area under the ROC (AUC) of Ppv-aCO₂ was 0.814 (95%CI: 0.696- 0.931, P &lt; 0.001), and at the best cut- off value of 9.05 mmHg, Ppv-aCO₂ had a sensitivity of 70.4% and a specificity of 88.6% for predicting 28-day mortality. The AUC of lactate level was 0.732 (95%CI: 0.607-0.858, P=0.002), and its sensitivity for predicting 28-day mortality was 70.4% and the specificity was 74.3% at the best cut-off value of 3.45 mmol/L; The AUC of Pcv-aCO₂ was 0.766 (95%CI: 0.642-0.891, P &lt; 0.001), and its sensitivity was 66.7% and the specificity was 80.0% at the best cut-off value of 7.05 mmHg.

CONCLUSIONS

A high Ppv-aCO₂ after early resuscitation of septic shock is associated with poor outcomes. Ppv-aCO₂ is well correlated with Pcv-aCO₂ and can be used as an independent indicator for predicting 28-day mortality in patients with septic shock.

Transthoracic Echocardiography of the Neonatal Laboratory Piglet

Background: Newborn piglets are commonly used in biomedical research. However, cardiovascular imaging of this species is quite challenging. For point of care diagnostics of heart function transthoracic echocardiography may be used, which appears to differ comparing newborn piglets with adult pigs. To date, there are few data or studies on the feasibility and quality of measurement of functional echocardiographic parameters in very small neonatal piglets. Objectives: To study the feasibility of transthoracic echocardiography in very small newborn piglets in supine position. Methods: In 44 anesthetized and intubated newborn piglets, positioned in supine position [age 32 h (12-44 h), weight 1,220 g (1,060-1,495 g), median (IQR)] transthoracic echocardiography was performed using a point of care ultrasound device (M-Turbo^©, FujiFilm SonoSite BV, Amsterdam, Netherlands), and a standard ultrasound transducer. Results: Using 2D- and M-mode-imaging left- and right-sided heart structures were accessible to transthoracic echocardiography in neonatal piglets. Diameters of the interventricular septum, the left ventricle, and the posterior wall were measured and ejection fraction and shortening fraction was calculated. Both left and right ventricular outflow tract could be imaged, and ventricular filling and systolic function could be evaluated. Furthermore, we were able to assess shunts of fetal circulation, such as patent ductus arteriosus, structure of the heart valves and congenital heart defects including ventricular septal defect. Conclusions: In summary, transthoracic echocardiography is feasible for assessment of cardiovascular function even in very small newborn laboratory piglets in supine position.

Comparison of different techniques of central venous pressure measurement in mechanically ventilated critically ill patients

BACKGROUND

Several techniques exist for measuring central venous pressure (CVP) but little information is available about the accuracy of each method. The aim of this study was to compare different methods of CVP measurements in mechanically ventilated patients.

METHODS

CVP was measured in mechanically ventilated patients without spontaneous breathing using four different techniques: 1) end expiratory CVP measurement at the base of the" c" wave (CVP_MEASURED), chosen as the reference method; 2) CVP measurement from the monitor averaging CVP over the cardiac and respiratory cycles (CVP_MONITOR); 3) CVP measurement after a transient withdrawing of mechanical ventilation (CVP_NADIR); 4) CVP measurement corrected for the transmitted respiratory pressure induced by intrinsic PEEP (calculated CVP: CVP_CALCULATED). Bias, precision, limits of agreement, and proportions of outliers (difference > 2 mm Hg) were determined.

RESULTS

Among 61 included patients, 103 CVP assessments were performed. CVP_MONITOR bias [-0.87  (1.06) mm Hg] was significantly different from those of CVP_CALCULATED [1.42  (1.07), P < 0.001 and CVP_NADIR (1.04  (1.29), P < 0.001]. The limits of agreement of CVP_MONITOR [-2.96 to 1.21 mm Hg] were not significantly different to those of CVP_NADIR (-1.49 to 3.57 mm Hg, P = 0.39) and CVP_CALCULATED (-0.68 to 3.53 mm Hg, P = 0.31). The proportion of outliers was not significantly different between CVP_MONITOR (n = 5, 5%) and CVP_NADIR (n = 9, 9%, P = 0.27) but was greater with CVP_CALCULATED (n = 16, 15%, P = 0.01).

CONCLUSIONS

In mechanically ventilated patients, CVP_MONITOR is a reliable method for assessing CVP_MEASURED Taking into account transmitted respiratory pressures, CVP_CALCULATED had a higher proportion of outliers and precision than CVP_NADIR.