Venous blood gases in pediatric patients: a lost art?

Acute Effects of Sodium Bicarbonate in Children with Congenital Heart Disease with Biventricular Circulation in Non-cardiac Arrest Situations

Despite the controversy, sodium bicarbonate is a commonly used medication in critically ill patients of all ages. There is a lack of data on the acute impact on hemodynamic parameters, biomarker indicators of cardiac output, and changes in vasoinotropic support after sodium bicarbonate therapy. In our retrospective study on children with biventricular circulation in pediatric cardiac intensive care unit receiving bicarbonate therapy: we analyzed its effects on arterial blood gases, heart rate, blood pressure (BP), central venous pressures (CVP), cerebral and renal near-infrared spectroscopy (NIRS), changes in vasoinotropic and ventilator changes before and after sodium bicarbonate administration. Thirty-one administrations of sodium bicarbonate in 23 patients with congenital heart disease without residual shunts were analyzed. The average age was 15.4 months, weight 7.7 kg, and the average bicarbonate dose was 1 meq/kg. There was an increase in arterial pH from 7.24 to 7.30 (p = 0.14) and bicarbonate changed from 18 to 20 mEq/L (p = 0.23). No clinically significant changes were found in the following parameters: heart rate (141 ± 20.1 to 136 ± 19), systolic BP (84 ± 17 to 86 ± 14 mmHg), diastolic BP (48 ± 12 to 49 ± 12 mmHg), cerebral NIRS (64 ± 12 to 65 ± 12), renal NIRS (80 ± 10 to 81 ± 7), CVP (9 ± 3 to 10 ± 4 mmHg), paCO₂ (45 ± 26 to 42 ± 7 mmHg), paO₂ (143 ± 78 to 127 ± 59 mmHg), serum lactate (2.2 ± 2.7 to 3.6 ± 3.8 mmol/L), and vasoinotropic score (7.5 ± 5.0 to 7.7 ± 4.7). Outside of a change in serum pH and bicarbonate levels no other significant changes were noted after sodium bicarbonate administration in children with congenital heart disease with fully septated, biventricular circulation. There was no improvement in systemic oxygen delivery.

Hemodynamic Response to Fluid Boluses in Patients with Single-Ventricle Parallel Circulation

The purpose of this study is to assess the effect of fluid bolus in response to a hypotensive episode by evaluating high-fidelity hemodynamic data obtained from children with single-ventricle anatomy and parallel circulation. Single center, retrospective analysis of hemodynamic and oximetric data after fluid bolus administrations within the first 2 weeks post-surgery. A baseline (- 60 to - 10 min), hypotensive episode (- 10 to 0 min), and response interval (0 to 60 min) were defined to quantify the dynamics of vital signs. The responses assessed include heart rate, blood pressure, oxygen saturation, oxygen extraction ratios, and pulmonary-to-systemic flow ratios. Mixed effects models were used to account for the repeated measures over the response interval. The analysis included 67 fluid boluses. There is a decrease in heart rate and an increase in blood pressure during the response in comparison to the hypotensive time. These vitals rapidly return to the baseline values. The boluses induced a significant decrease in renal and cerebral oxygen extraction ratios, with no significant change in arterial oxygen saturation or pulmonary-to-systemic flow ratio. The type of bolus (normal saline versus albumin) did not affect the response in blood pressure. However, in comparison with albumin, normal saline had a more favorable effect on the renal and cerebral oxygen extraction ratios. This study demonstrates that fluid boluses are an effective rescue medication for hypotensive episodes in children with parallel circulation by improving hemodynamics, as well as markers of oxygen delivery. The type of bolus (normal saline versus albumin) did not affect the blood pressure response. However, normal saline had a more pronounced effect on the renal and cerebral oxygen extraction ratios than albumin.

Association of Immediate Postoperative Hemodynamic and Laboratory Values in Predicting Norwood Admission Outcomes

The primary objective of this study was to determine whether or not hemodynamic parameters and laboratory values at the time of admission to the pediatric cardiac intensive care unit after the Norwood operation were associated with a composite outcome of either need for extracorporeal membrane oxygenation or inpatient mortality. This was a single-center retrospective study of infants with functionally univentricular hearts admitted to intensive care after the Norwood procedure from January 2011 to January 2020. Data were obtained at a single point (after a Norwood procedure) and then compared between two subsets of patients based on the presence or not of the composite outcome of interest. In univariate and multiple regression analyses, a series of receiver operator curves were generated to assess the relationship between the variables of interest and the composite outcome. Eight (7.6%) experienced the composite outcome out of a total of 104 patients. Those who experienced the composite endpoint had significantly higher oxygen extraction ratio (0.43 vs. 0.31, p = 0.01), lower systemic blood flow (2.5 L/min versus 3.1 L/min, p = 0.01), and higher systemic vascular resistance (20.2 indexed woods units versus 14.8 indexed woods units, p = 0.01). Those with systemic blood flow of less than 2.5 L/min/m2 had a 17% risk of experiencing the composite endpoint AUC = 0.79. Those with systemic vascular resistance of greater than 19 indexed woods units had a 22% risk of experiencing the composite endpoint AUC 0.80. Systemic blood flow and systemic vascular resistance are independently associated with this composite outcome.

Peri-Intubation Cardiorespiratory Arrest Risk in Pediatric Patients: A Systematic Review

Endotracheal intubation is associated with an increased risk of cardiorespiratory arrest. Various factors modulate the risk of peri-intubation cardiorespiratory arrest. The primary objective of this study was to determine the risk of peri-intubation cardiorespiratory arrest in pediatric patients in a hospital setting, and the secondary objective was to determine the effect of various factors on the peri-intubation cardiorespiratory arrest risk. A systematic review was performed to identify eligible manuscripts. Studies were deemed appropriate if they included pediatric patients in a hospital setting not exclusively intubated for an indication of cardiorespiratory arrest. Data were extracted from studies deemed eligible for inclusion. A pooled risk of cardiorespiratory arrest was determined. A Bayesian linear regression was conducted to model the risk of cardiorespiratory arrest. All data used in this were study-level data. A total of 11 studies with 14,424 intubations were included in the final analyses. The setting for six (54.5%) studies was the emergency department. The baseline adjusted risk for peri-intubation cardiorespiratory arrest in pediatric patients was 3.78%. The mean coefficient for a respiratory indication for intubation was −0.06, indicating that a respiratory indication for intubation reduced the per-intubation cardiorespiratory arrest risk by 0.06%. The mean coefficient for use of ketamine was 0.07, the mean coefficient for use of a benzodiazepine was −0.14, the mean coefficient for use of a vagolytic was −0.01, and the mean coefficient for use of neuromuscular blockade was −0.40. Pediatric patients during the peri-intubation period have the risk of developing cardiorespiratory arrest. The pooled findings demonstrate associations that seem to highlight the importance of maintaining adequate systemic oxygen delivery to limit this risk.