ABSTRACT
OBJECTIVE: To assess whether the passive leg raising (PLR) test can predict fluid responsiveness in pediatric patients. METHODS: This was a prospective observational study in a tertiary care pediatric center. Hemodynamic parameters including heart rate, stroke volume and cardiac output were assessed at baseline, after passive leg raising (PLR), at second baseline, and after volume loading (10 mL/kg normal saline in 10 min). Cutoff values of 7.5 and 10 % increase in cardiac index (CI) with passive leg raising were explored as predictors of volume loading response. RESULTS: Overall, the changes in CI with passive leg raising varied widely and was a poor predictor of response to volume loading in children under 5 years of age. Of 40 patients, 23 had greater than 10 % increase in CI with PLR which predicted fluid responsiveness with a sensitivity of 94 % (95 % confidence interval 71,100) and specificity of 26 % (95 % confidence interval 10,48). Sensitivity was higher (100 % vs. 91 %) and specificity similar (27 % vs. 25 %) in predicting CI for those over 5 as compared to under 5 y, respectively. In patients over 5 y, simple linear regression revealed a positive correlation (R(2) = 21) while R(2) values were much lower (0-0.07) for those under 5 y. CONCLUSIONS: Cardiac index changes after PLR varies widely in children and may be a poor predictor to volume loading in children under 5-y-old. However, in those over 5 y, PLR may be helpful in predicting fluid responsiveness in pediatric patients.
Subject(s)
Fluid Therapy , Hemodynamics , Resuscitation/methods , Shock , Cardiac Output , Child , Child, Preschool , Diagnostic Techniques, Cardiovascular , Female , Fluid Therapy/adverse effects , Fluid Therapy/methods , Heart Rate , Humans , India , Male , Monitoring, Physiologic/methods , Prospective Studies , Reproducibility of Results , Risk Assessment/methods , Shock/diagnosis , Shock/physiopathology , Shock/therapyABSTRACT
OBJECTIVE: To evaluate the effect of continuous blood purification on cardiac function and plasma vasoactive substances in endotoxic shock in piglets. DESIGN: This was a randomized controlled trial in an animal laboratory in a tertiary care pediatric center. MATERIALS AND METHODS: Twenty-three healthy Shanghai white piglets weighing 8-14 kg were randomly assigned to one of the four groups: control group (n = 5), continuous blood purification without lipopolysaccharide infusion group (continuous blood purification, n = 6), lipopolysaccharide-induced endotoxin shock without continuous blood purification group (lipopolysaccharide, n = 6), and lipopolysaccharide-induced endotoxin shock with continuous blood purification group (continuous blood purification/lipopolysaccharide, n = 6). INTERVENTIONS: The lipopolysaccharide and continuous blood purification/lipopolysaccharide groups were injected intravenously with Escherichia coli endotoxin to induce septic shock. The continuous blood purification and continuous blood purification/lipopolysaccharide groups received continuous venovenous hemodiafiltration right after model establishment. At baseline state (T0), following the injection of lipopolysaccharide (T), 1 hr later (T1), 3 hrs later (T3), and 5 hrs later (T5) after model establishment, clinical systemic inflammatory response syndrome parameters, hemodynamic indexes, and plasma concentration of vasoactive substances were obtained. Plasma concentration of dopamine was measured by enzyme-linked immunosorbent assay (DSL Company) and endothelin-1 by enzyme-linked immunosorbent assay (R&D Company). Nitric oxide synthase activity was measured by chromatometry (Nanjing Jiancheng Bioengineering Institute, China). MEASUREMENTS AND MAIN RESULTS: In continuous blood purification/lipopolysaccharide group, after treatment with CPB, heart rate decreased significantly (p < .05) and pulse contour cardiac index, systematic vascular resistance index, and stroke volume index increased significantly (p < .05) when compared with lipopolysaccharide and continuous blood purification groups. After treatment with continuous blood purification, dopamine and endothelin-1 level increased and nitric oxide synthase activities decreased in continuous blood purification/lipopolysaccharide group when compared with the lipopolysaccharide group. In the continuous blood purification/lipopolysaccharide group, improvement in hemodynamic indexes was strongly correlated with increases in plasma dopamine and endothelin-1 level and decreases in nitric oxide synthase activity (r > .9, p < .05). CONCLUSIONS: The adverse cardiovascular effects of lipopolysaccharide-induced endotoxin shock can be improved by continuous blood purification. Improvement is correlated with increases in the concentration of plasma vasoactive substances (endothelin and dopamine) and decreases in nitric oxide synthase activity.
Subject(s)
Endotoxins , Escherichia coli , Hemofiltration , Shock, Septic/therapy , Animals , Disease Models, Animal , Dopamine/blood , Endothelin-1/blood , Heart Rate , Lipopolysaccharides , Nitric Oxide Synthase/blood , Shock, Septic/blood , Shock, Septic/chemically induced , Shock, Septic/physiopathology , Statistics, Nonparametric , Stroke Volume , Swine , Vascular ResistanceABSTRACT
OBJECTIVE: To evaluate the effect of continuous veno-venous hemodialysis filtration (CVVHDF) on cardiopulmonary function and clearance of inflammatory mediators in piglets with endotoxin-induced acute lung injury. DESIGN: A randomized controlled trial. SETTING: An animal laboratory in a tertiary care pediatric center. SUBJECTS: : Eighteen piglets, weighing 6-8 kg. INTERVENTIONS: The piglets were anesthetized, ventilated, and received an intravenous infusion of 150 µg/kg of endotoxin. They were then randomly divided into three groups: control group (n = 6) received Ringer's lactate solution; the heparin group (n = 6) received heparin infusion plus Ringer's lactate solution; and the CVVHDF group (n = 6) received CVVHDF plus heparin infusion and Ringer's lactate solution. MEASUREMENTS AND MAIN RESULTS: Parameters measured simultaneously were: heart rate, mean arterial blood pressure, central venous pressure, pulse contour cardiac index, cardiac function index, left ventricular contractile index, and systemic vascular resistance index; extra vascular lung water index, respiratory rate, dynamic pulmonary compliance, airway resistance, Pao2/Fio2 ratio, serum tumor necrosis factor-α, and soluble tumor necrosis factor receptor. Lung tissue was obtained for pathologic lung injury scoring and wet/dry weight ratio. Endotoxin challenge decreased oxygenation and pulmonary mechanics, suppressed cardiac function, increased extravascular lung water, and elevated serum inflammatory mediators (tumor necrosis factor-α and soluble tumor necrosis factor receptor). After CVVHDF, pulmonary function and oxygenation improved (Pao2/Fio2, 291.5 ± 75.9 vs. 217.2 ± 45.4, respectively, p < .05); arterial blood pressure and cardiac function were restored (pulse contour cardiac index, 3.95 ± 0.52 L/min/m(2) vs. 2.69 ± 0.49 L/min/m(2), respectively, p < .05); extravascular lung water decreased, and serum inflammatory markers also decreased. Lung injury score improved and wet/dry weight ratio decreased. CONCLUSION: Early CVVHDF has a beneficial effect on acute lung injury in piglets and is associated with a reduction in inflammatory cytokines, improving pulmonary function and hemodynamics and decreasing extravascular lung water and lung damage.
