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Early Central Venous-to-Pa co2 Difference and Subsequent Lactate Clearance in Shock: Prospective Pediatric Cohort,
Raíssa A R B Teixeira1, Caio C Mendonça, Sayara S G Melocra
1All authors: Division of Pediatric Critical Care Medicine, Department of Pediatrics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil.
Insights
Early central venous-to-arterial PCO2 difference (∆PCO2) in pediatric shock correlates with lactate clearance. This metric may aid in early resuscitation and severity assessment for critically ill children.
Area of Science:
- Pediatric Critical Care Medicine
- Hemodynamics
- Shock Pathophysiology
Background:
- Shock in children requires timely and accurate assessment of resuscitation effectiveness.
- Lactate concentration is a common marker for tissue hypoperfusion, but its interpretation can be complex.
- Early indicators of treatment response are crucial for improving outcomes in pediatric shock.
Purpose of the Study:
- To evaluate the early central venous-to-arterial PCO2 difference (∆PCO2) in pediatric shock.
- To determine the correlation between early ∆PCO2 and subsequent lactate concentration and clearance.
- To assess the utility of ∆PCO2 as an early marker for resuscitation and severity stratification.
Main Methods:
- Prospective observational study in two pediatric intensive care units.
- Included children (<18 years) with septic or cardiogenic shock.
- Measured ∆PCO2, lactate, lactate clearance, and central venous oxygen saturation (ScvO2) at multiple time points.
Main Results:
- Children with ∆PCO2 > 6 mm Hg at 6 hours had higher Vasoactive-Inotropic Scores, Pediatric Logistic Organ Dysfunction scores, lower LVEF, and worse lactate parameters.
- ∆PCO2 positively correlated with lactate and negatively with lactate clearance and ScvO2.
- A ∆PCO2 cutoff of 7.5 mm Hg at 6 hours predicted poor lactate clearance at 24 hours with an AUC of 0.81.
Conclusions:
- Early ∆PCO2 (at 6 hours) is a valuable predictor of subsequent lactate clearance in pediatric shock.
- ∆PCO2 may serve as an early resuscitation and severity stratification metric in pediatric shock patients.
- Further research could explore the integration of ∆PCO2 into clinical decision-making algorithms.
Objectives:
To evaluate early central venous-to-Pa co2 difference (∆P co2 ) and its correlation with later lactate concentration in pediatric patients with shock.
Design:
Prospective observational study.
Setting:
Two medical-surgical PICUs in a tertiary-care university hospital.
Patients:
Children younger than 18 years old with septic or cardiogenic shock admitted to the PICUs (March 2021 to December 2022).
Interventions:
None.
Measurements And Main Results:
Demographic, clinical, and outcome data were collected from medical records. Arterial and central venous blood samples were collected simultaneously at PICU admission and 6, 24, and 48 hours after admission to determine ∆P co2 , arterial lactate concentration, lactate clearance, and central venous oxygen-hemoglobin saturation (Scv o2 ). Left ventricle ejection fraction (LVEF) was estimated by echocardiography. Fifty-four patients 1.1 to 203.1 months old (median, 25.2 mo old) were included: (43/54 [79.6%] had septic shock and 11/54 [20.4%] had cardiogenic shock). Patients were divided into two groups according to ∆P co2 at 6 hours (24 ≤ 6 mm Hg and 30 > 6 mm Hg). The group with ∆P co2 greater than 6 mm Hg, compared with the group less than or equal to 6 mm Hg, had a higher Vasoactive-Inotropic Score and Pediatric Logistic Organ Dysfunction score, and there was a higher proportion of patients with low LVEF, elevated lactate concentrations, reduced lactate clearance, and Scv o2 less than 70%. ∆P co2 positively correlated with lactate concentrations and negatively correlated with lactate clearance and Scv o2 . The ∆P co2 cutoff of 7.5 mm Hg at 6 hours had sensitivity of 0.70, specificity of 0.76, positive predictive value of 0.87, and negative predictive value of 0.54 for predicting lactate clearance less than 10% at 24 hours (area under the receiver operating characteristic curve, 0.81 [95% CI, 0.69-0.91]). There were no differences in clinical outcomes between the groups.
Conclusions:
In pediatric shock, ∆P co2 measured 6 hours after presentation is correlated with subsequent lactate clearance at 24 hours and may serve as an early resuscitation and severity stratification metric.
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