Acute kidney injury in children undergoing cardiac surgery: predictive value of kidney arterial Doppler-based variables.

BACKGROUND: Acute kidney injury (AKI) is a common condition in critically ill children and is associated with increased morbidity and mortality. This study aimed to assess the performance of point-of-care ultrasonography to predict AKI in children undergoing cardiac surgery. METHODS: In this prospective study, consecutive children underwent kidney Doppler ultrasound examination within 24 h following cardiac surgery, and an experienced operator obtained both renal resistive index (RRI) and renal pulsatility index (RPI). AKI was defined by the Kidney Disease Improving Global Outcome (KDIGO) criteria. The primary outcome was the diagnosis of severe AKI (KDIGO stage 2 or 3) on day 3. RESULTS: A total of 58 patients were included. Median age and weight were 12.9 months (IQR 6.0-37.9) and 7.36 kg (IQR 5.19-11.40), respectively. On day 3, 13 patients were classified as having AKI, of which 11 were severe. RRI could effectively predict AKI (area under the ROC curve [AUC] 0.83, 95% CI 0.71-0.92; p < 0.001) as well as RPI (AUC 0.81, 95% CI 0.69-0.90; p < 0.001). The optimal cutoff value for RRI was 0.85 (sensitivity, 73%; specificity, 83%; positive predictive value [PPV], 50%; and negative predictive value [NPV], 93%), while for RPI was 1.95 (sensitivity, 73%; specificity, 78%; PPV, 44%; and NPV, 92%). Similar results were found in the analysis for prediction on day 5. Significant correlations were found between Doppler-based variables and estimated GFR and furosemide dose on day 3. CONCLUSIONS: Kidney Doppler ultrasound may be a promising tool for predicting AKI in children undergoing cardiac surgery.

Accuracy of Respiratory Variation in Inferior Vena Cava Diameter to Predict Fluid Responsiveness in Children Under Mechanical Ventilation.

Proper assessment of fluid responsiveness using accurate predictors is crucial to guide fluid therapy and avoid the serious adverse effects of fluid overload. The main objective of this study was to investigate the accuracy of respiratory variations in inferior vena cava diameter (∆IVC) to predict fluid responsiveness in mechanically ventilated children. This prospective single-center study included 32 children (median age and weight of 17 months and 10 kg, respectively) who received a fluid infusion of 10 ml kg-1 of crystalloid solutions over 10 min. ∆IVC and respiratory variation in aortic blood flow peak velocity (∆Vpeak) were determined over one controlled respiratory cycle before and after fluid loading. Thirteen (41%) participants were fluid-responders. ∆IVC, ∆Vpeak, stroke volume index, and cardiac index were found to be predictors of fluid responsiveness. However, the area under the ROC curve of ∆IVC was smaller when compared to ∆Vpeak (0.709 vs. 0.935, p < 0.012). The best cut-off values were 7.7% for ∆IVC (sensitivity, 69.2%; specificity 78.9%, positive predictive value, 69.2%; and negative predictive value, 78.9%) and 18.2% for ∆Vpeak (sensitivity, 84.6%; specificity, 89.5%; positive predictive value, 84.6%; negative predictive value, 89.5%). Changes in stroke volume were positively correlated with ∆IVC (ρ = 0.566, p < 0.001) and ∆Vpeak (ρ = 0.603, p < 0.001). A significant correlation was also found between changes in MAP and ∆Vpeak (ρ = 0.382; p = 0.031), but the same was not observed with ∆IVC (ρ = 0.011; p = 0.951). In conclusion, ∆IVC was found to have a moderate accuracy in predicting fluid responsiveness in mechanically ventilated children and is an inferior predictor when compared to ∆Vpeak.

Carotid Doppler Ultrasonography for Hemodynamic Assessment in Critically Ill Children.

An accurate assessment of cardiovascular performance is essential to predict and evaluate hemodynamic response to interventions. The objective of this prospective study was to assess whether point-of-care ultrasonography of the common carotid artery (CCA) can estimate the stroke volume (SV) and cardiac index (Ci) of critically ill children. Participants underwent Doppler ultrasonography of the left CCA and transthoracic echocardiography (TTE). Variables measured by TTE were SV and Ci. Carotid blood flow (CBF) was calculated based on both systolic velocity-time integral (CBF(s)) and total velocity-time integral (CBF(t)). Carotid corrected flow time(CFT)was also determined. A total of 50 children were enrolled. The median age and weight of participants were 36.0 months and 14.2 kg, respectively. Both CBF(s) and CBF(t) correlated very strongly with SV (ρ = 0.98 and 0.97, respectively) and Ci (ρ = 0.96 and 0.92, respectively). Agreement analysis showed low biases and clinically acceptable percentage errors between variables measured by TTE (SV and Ci) and those estimated by Doppler ultrasonography. Linear regression analysis revealed that the Ci of mechanically ventilated children can be estimated by the following equation: [Formula: see text]. CFT did not significantly correlate with SV or Ci (ρ = 0.27 and 0.05, respectively). Doppler ultrasonography of the left CCA is able to estimate the SV and Ci of critically ill children. Therefore, the CDU may be considered as an alternative for estimating Ci in critically ill children when TTE is not feasible or available.

Sarcopenia in critically ill children: A bedside assessment using point-of-care ultrasound and anthropometry.

BACKGROUND & AIMS: Due to the lack of validated methods of muscle assessment, sarcopenia is not well described in critically ill children. The main objectives of this study were to assess muscle wasting using point-of-care ultrasound (POCUS) and anthropometry, as well as its association with nutrition delivery in PICU. METHODS: This was a single-center, prospective cohort study, including consecutive children admitted to the PICU. Quadriceps femoris muscle thickness (QFMT) and anthropometrics measurements were performed at admission and then weekly until the 14th day of the PICU stay. The three moments of assessment were defined as T0 (baseline), T1 (7th day) and T2 (14th day). For analysis purposes, participants assessed only in T0 and T1 were defined as Subgroup 1, while those assessed in T0, T1 and T2 were defined as Subgroup 2. Actual total daily intake was determined by patient intake records until discharge or during the first 14 full days of PICU admission. RESULTS: In all, 119 patients were included with a median age of 12.0 months (IQR 4.0-42.5). In Subgroup 1, QFMT significantly decreased between T0 and T1 (-12.93 ± 14.07 %; p < 0.001), and the same was observed in Subgroup 2 (-13.81 ± 13.05 %; p < 0.001). However, no differences in QFMT was observed between T1 and T2 (-2.06 ± 13.80 %; p = 0.936). Triceps skinfold thickness, mid-upper arm circumference, and upper arm muscle area presented a similar pattern of changes between periods in both groups. Decrease of QFMT at T1 was significantly correlated with the cumulative protein deficit in both subgroups, but not with the cumulative energy deficit. CONCLUSION: Substantial muscle wasting occurs early in critically ill children and may be related to insufficient protein delivery. Anthropometric measurements are valuable in PICU and POCUS has the potential to play a major role in sarcopenia assessment during critical illnesses. TRIAL REGISTRATION: Brazilian Clinical Trials registry, registration number: RBR-85YYGN.

Efficient photodynamic inactivation of Leishmania parasites mediated by lipophilic water-soluble Zn(II) porphyrin ZnTnHex-2-PyP4.

BACKGROUND: Photodynamic inactivation (PDI) is emerging as a promising alternative for cutaneous leishmaniasis (CL). The chemotherapy currently used presents adverse effects and cases of drug resistance have been reported. ZnTnHex-2-PyP4+ is a porphyrin with a high potential as a photosensitizer (PS) for PDI, due to its photophysical properties, structural stability, and cationic/amphiphilic character that can enhance interaction with cells. This study aimed to investigate the photodynamic effects mediated by ZnTnHex-2-PyP4+ on Leishmania parasites. METHODS: ZnTnHex-2-PyP4+ stability was evaluated using accelerated solvolysis conditions. The photodynamic action on promastigotes was assessed by (i) viability assays, (ii) mitochondrial membrane potential evaluation, and (iii) morphological analysis. The PS-promastigote interaction was studied. PDI on amastigotes and the cytotoxicity on macrophages were also analyzed. RESULTS: ZnTnHex-2-PyP4+, under submicromolar concentration, led to immediate inactivation of more than 95% of promastigotes. PDI promoted intense mitochondrial depolarization, loss of the fusiform shape, and plasma membrane wrinkling in promastigotes. Fluorescence microscopy revealed a punctate PS labeling in the parasite cytoplasm. PDI also led to reductions of ca. 64% in the number of amastigotes/macrophage and 70% in the infection index after a single treatment session. No noteworthy toxicity was observed on mammalian cells. CONCLUSIONS: ZnTnHex-2-PyP4+ is stable against demetallation and more efficient as PS than the ethyl analogue ZnTE-2-PyP4+, indicating readiness for evaluation in in vivo studies as an alternative approach to CL. GENERAL SIGNIFICANCE: This report highlighted promising photodynamic effects mediated by ZnTnHex-2-PyP4+ on Leishmania parasites, opening up perspectives for applications in CL pre-clinical assays and PDI of other microorganisms.

High-frequency oscillatory ventilation in children: A systematic review and meta-analysis.

BACKGROUND: High-frequency oscillatory ventilation (HFOV) is an alternative mechanical ventilation mode proposed to reduce ventilator-induced lung injuries and improve clinical outcomes. The aim of this study was to determine the effects of HFOV compared to conventional mechanical ventilation (CMV) when used in children with hypoxemic respiratory failure. METHODS: The literature search was conducted to identify all studies published before December 2020. Eligible studies included a population aged between 28 days and 18 years old, presented original data from randomized controlled trials (RCTs) or observational studies, compared the use of HFOV with CMV. Meta-analyses of the pooled data were performed by using random-effects models with inverse-variance weighting. RESULTS: A total of 11 studies (2605 cases) were included, most of them evaluating patients with acute respiratory distress syndrome. The mean age of participants was 8.2 months and the mean oxygenation index of those included in the RCTs was 24.4. The effect of HFOV on mortality was not significant, and clinically significant harm or benefit could not be excluded (risk ratio [RR], 0.93; 95% confidence interval [CI], 0.72 to 1.20). No significant difference between groups was found in duration of mechanical ventilation (-2.23; 95% CI, -5.07 to 0.61), treatment failure (RR, 0.28; 95% CI, 0.08 to 1.02), and occurrence of barotrauma (RR, 0.88; 95% CI, 0.39 to 1.99). CONCLUSION: The scarce evidence currently available does not allow us to conclude that HFOV has advantages over CMV and further studies are needed to clarify its role in the treatment of acute hypoxemic respiratory failure in children.

Clinical manifestations of children with COVID-19: A systematic review.

BACKGROUND: The coronavirus disease 2019 (COVID-19) outbreak is an unprecedented global public health challenge, leading to thousands of deaths every day worldwide. Despite the epidemiological importance, clinical patterns of children with COVID-19 remain unclear. The aim of this study was to describe the clinical, laboratorial, and radiological characteristics of children with COVID-19. METHODS: The Medline database was searched between December 1st 2019 and April 6th 2020. No language restrictions were applied. Inclusion criteria were (a) studied patients younger than 18 years old; (b) presented original data from cases of COVID-19 confirmed by reverse-transcription polymerase chain reaction; and (c) contained descriptions of clinical manifestations, laboratory tests, or radiological examinations. RESULTS: A total of 38 studies (1124 cases) were included. From all the cases, 1117 had their severity classified: 14.2% were asymptomatic, 36.3% were mild, 46.0% were moderate, 2.1% were severe, and 1.2% were critical. The most prevalent symptom was fever (47.5%), followed by cough (41.5%), nasal symptoms (11.2%), diarrhea (8.1%), and nausea/vomiting (7.1%). One hundred forty-five (36.9%) children were diagnosed with pneumonia and 43 (10.9%) upper airway infections were reported. Reduced lymphocyte count was reported in 12.9% of cases. Abnormalities in computed tomography were reported in 63.0% of cases. The most prevalent abnormalities reported were ground-glass opacities, patchy shadows, and consolidations. Only one death was reported. CONCLUSIONS: Clinical manifestations of children with COVID-19 differ widely from adult cases. Fever and respiratory symptoms should not be considered a hallmark of COVID-19 in children.

Inferior Vena Cava Ultrasound in Children: Comparing Two Common Assessment Methods.

OBJECTIVES: Inferior vena cava ultrasound has been used as a predictor of fluid responsiveness in children. Two ultrasonographic modes can be used to measure the respiratory variation of inferior vena cava diameter: M-mode and B-mode. Inconsistencies in measurements between the modes can result in inaccuracies in commonly used indices that assess fluid responsiveness. Our primary objective was to determine whether there are differences in the ultrasound-based measurements between these two modes of evaluation, which would impact respiratory variation of inferior vena cava diameter calculation. Our secondary objective was to assess inferior vena cava displacements during the respiratory cycle as a possible mechanism for measurement differences between the modes. DESIGN: Prospective observational study. SETTING: PICU of a tertiary care teaching hospital. PATIENTS: Seventy-three children under controlled ventilation (median age of 16 mo and weight of 10 kg). INTERVENTIONS: The inferior vena cava diameters were measured using a longitudinal view using B- and M-mode ultrasound. Two respiratory variation of inferior vena cava diameter indices were evaluated: distensibility and respiratory variation. Maximum craniocaudal and mediolateral displacements of the inferior vena cava were measured using the B-mode ultrasound. MEASUREMENTS AND MAIN RESULTS: Maximum diameters of the inferior vena cava were similar between the B- and M-modes (7.90 vs 7.90 mm, respectively; p = 0.326), but minimum diameters were smaller when measured by M-mode (6.36 vs 5.00 mm; p = 0.003). When calculated by data obtained from M-mode, respiratory variation of inferior vena cava diameter indices presented significantly higher values compared to B-mode measures (p ≤ 0.001, for both). Median inferior vena cava displacements were 5.00 mm (interquartile range, 3.68-6.26 mm) in the craniocaudal and 0.80 mm (interquartile range, 0.12-1.23 mm) in the mediolateral directions. CONCLUSIONS: There is a significant difference between measurements of the minimum inferior vena cava diameter observed in M- and B-mode ultrasound during the respiratory cycle in children under controlled ventilation. This results in imprecise respiratory variation of inferior vena cava diameter indices. Displacements of the inferior vena cava during the respiratory cycle may influence the reliability of ultrasonographic measurements, particularly in M-mode.

The Use of Ultrasound as a Tool to Evaluate Pulmonary Disease in Cystic Fibrosis.

BACKGROUND: Lung ultrasound is an examination that allows the assessment of pulmonary involvement by analyzing artifacts. Our primary aim was to correlate our lung ultrasound findings with pulmonary function and the modified Bhalla score in patients with cystic fibrosis. METHODS: Subjects with cystic fibrosis were evaluated based on the results of lung ultrasound, pulmonary function exams (ie, spirometry before and after the use of a bronchodilator and SpO2 ), and the modified Bhalla score. The partial correlation set by age between lung ultrasound, pulmonary function, and modified Bhalla score was carried out. Lung ultrasound was graded according to a new score, ranging from 0 to 36, with a higher score being associated with a greater degree of involvement. We performed Bland-Altman and linear regression analysis to identify bias between lung ultrasound and modified Bhalla score. Alpha = 0.05. RESULTS: 18 subjects with cystic fibrosis were included. In partial correlation controlled by age, we observed significant ultrasound score values with weight (partial correlation = -0.579), body mass index (partial correlation = -0.609), SpO2 (partial correlation = -0.728), FVC% (pre-bronchodilator: partial correlation = -0.538; post-bronchodilator: partial correlation = -0.560), FEV1% (pre-bronchodilator: partial correlation = -0.536; post-bronchodilator: partial correlation = -0.546), and modified Bhalla score (partial correlation = 0.607). We did not identify bias between lung ultrasound and modified Bhalla score measured by z-score. CONCLUSIONS: Lung ultrasound seems to be effective and corroborates with high-resolution computed tomography when evaluated by the modified Bhalla score. At the same time, lung ultrasound had significant correlation with pulmonary function and nutritional status.

Evaluating viscoelastic properties and membrane electrical charges of red blood cells with optical tweezers and cationic quantum dots - applications to ß-thalassemia intermedia hemoglobinopathy.

Biomechanical and electrical properties are important to the performance and survival of red blood cells (RBCs) in the microcirculation. This study proposed and explored methodologies based on optical tweezers and cationic quantum dots (QDs) as biophotonic tools to characterize, in a complementary way, viscoelastic properties and membrane electrical charges of RBCs. The methodologies were applied to normal (HbA) and ß-thalassemia intermedia (Hbß) RBCs. The ß-thalassemia intermedia disease is a hereditary hemoglobinopathy characterized by a reduction (or absence) of ß-globin chains, which leads to α-globin chains precipitation. The apparent elasticity (µ) and membrane viscosity (ηm) of RBCs captured by optical tweezers were obtained in just a single experiment. Besides, the membrane electrical charges were evaluated by flow cytometry, exploring electrostatic interactions between cationic QDs, stabilized with cysteamine, with the negatively charged RBC surfaces. Results showed that Hbß RBCs are less elastic, have a higher ηm, and presented a reduction in membrane electrical charges, when compared to HbA RBCs. Moreover, the methodologies based on optical tweezers and QDs, here proposed, showed to be capable of providing a deeper and integrated comprehension on RBC rheological and electrical changes, resulting from diverse biological conditions, such as the ß-thalassemia intermedia hemoglobinopathy.

Acute Abdominal Pain as a Presenting Symptom of Beriberi in a Pediatric Patient.

Vitamin B1 (thiamine) plays a fundamental role in the proper functioning of the nervous and cardiovascular systems and in glucose metabolism. Because of the inability of the human body to store large amounts of vitamin, continuous restoration through diet is necessary. In the pediatric population, thiamine deficiency has a broad spectrum of clinical presentations, making diagnosis difficult. In this article, we report the case of a 7-month-old child with thiamine deficiency presented with neurological symptoms and simulation of acute abdomen. The patient received thiamine replacement, which resulted in rapid reversal of metabolic alterations and significant improvement in the signs and symptoms. A detailed investigation of dietary history and careful nutritional assessment of every critically ill pediatric patient is necessary, regardless of the primary cause of hospitalization.