Cardiac Arrest With or Without Need for Extracorporeal Life Support After Congenital Cardiac Surgery.

BACKGROUND: Postoperative cardiac arrest (CA) with or without need for extracorporeal cardiopulmonary resuscitation (ECPR) is one of the most significant complications in the early postoperative period after pediatric cardiac operation. The objective of this study was to develop and to validate a predictive model of postoperative CA with or without ECPR. METHODS: In this retrospective cohort study, we reviewed data from patients who underwent cardiac surgery with cardiopulmonary bypass (CPB) between July 20, 2020, and December 31, 2021. Variables included demographic data, presence of preoperative risk factors, The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery mortality categories, perioperative data, residual lesion score (RLS), and vasoactive-inotropic score (VIS). We used multivariable logistic regression analysis to develop a predictive model. RESULTS: The incidence of CA with or without ECPR was 4.4% (n = 24/544). Patients who experienced postoperative CA with or without ECPR were younger (age, 130 [54-816.5] days vs 626 [127.5-2497.5] days; P < .050) and required longer CPB (253 [154-332.5] minutes vs 130 [87-186] minutes; P < .010) and cross-clamp (116.5 [75.5-143.5] minutes vs 64 [30-111] minutes; P < .020) times; 37.5% of patients with an outcome had at least 1 preoperative risk factor (vs 16.9%; P < .010). Our multivariable logistic regression determined that the presence of at least 1 preoperative risk factor (P = .005), CPB duration (P = .003), intraoperative residual lesion score (P = .009), and postsurgery vasoactive-inotropic score (P = .010) were predictors of the incidence of CA with or without ECPR. CONCLUSIONS: We developed a predictive model of postoperative CA with or without ECPR after congenital cardiac operation. Our model performed better than the individual scores and risk factors.

Higher Cumulative Dose of Opioids and Other Sedatives are Associated with Extubation Failure in Norwood Patients.

BACKGROUND: The primary purpose of this study is to evaluate the relationship between sedation usage and extubation failure, and to control for the effects of hemodynamic, oximetric indices, clinical characteristics, ventilatory settings pre- and post-extubation, and echocardiographic (echo) findings in neonates with hypoplastic left heart syndrome (HLHS) post-Norwood procedure. METHODS: Single-center, retrospective analysis of Norwood patients during their first extubation post-surgery from January 2015 to July 2021. Extubation failure was defined as reintubation within 48 h of extubation. Demographics, clinical characteristics, ventilatory settings, echo findings (right ventricular function, tricuspid regurgitation), and cumulative dose of sedation medications before extubation were compared between patients with successful or failed extubation. RESULTS: The analysis included 130 patients who underwent the Norwood procedure with 121 (93%) successful and 9 (7%) failed extubations. Univariate analyses showed that vocal cord anomaly (p = 0.05), lower end-tidal CO2 (p < 0.01), lower pulse-to-respiratory quotient (p = 0.02), and ketamine administration (p = 0.04) were associated with extubation failure. The use of opioids, benzodiazepines, dexmedetomidine, and ketamine are mutually correlated in this cohort. On multivariable analysis, the vocal cord anomaly (OR = 7.31, 95% CI 1.25-42.78, p = 0.027), pre-extubation end-tidal CO2 (OR = 0.80, 95% CI 0.65-0.97, p = 0.025), and higher cumulative dose of opioids (OR = 10.16, 95% CI 1.25-82.43, p = 0.030) were independently associated with extubation failure while also controlling for post-extubation respiratory support (CPAP/BiPAP/HFNC vs NC), intubation length, and echo results. CONCLUSION: Higher cumulative opioid doses were associated with a greater incidence of extubation failure in infants post-Norwood procedure. Therefore, patients with higher cumulative doses of opioids should be more closely evaluated for extubation readiness in this population. Low end-tidal CO2 and low pulse-to-respiratory quotient were also associated with failed extubation. Consideration of the pulse-to-respiratory quotient in the extubation readiness assessment can be beneficial in the Norwood population.

Retrospective Comparison of Recombinant Activated Factor VII Versus 4-Factor Prothrombin Complex Concentrate in Cardiac Surgical Patients.

OBJECTIVES: To compare the incidences of postoperative thrombotic complications, transfusion of blood products, and chest tube output in congenital cardiac surgical patients who received either recombinant activated factor VII (rFVIIa) or 4-factor prothrombin complex concentrate (4F-PCC). DESIGN: We performed a retrospective study. SETTING: Patients who underwent surgery at a tertiary academic hospital. PARTICIPANTS: Pediatric patients who underwent cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data were obtained from the Society of Thoracic Surgeons and the Pediatric Cardiac Critical Care Consortium databases, as well as from manual chart review. Adjusted p values were obtained from multivariate regression using age (days), surgeon (number), cardiopulmonary bypass time (minutes), and need for deep hypothermic circulatory arrest (yes/no). A total of 55 patients were included in the 4F-PCC group, and 89 in the rFVIIa group. The median dose of rFVIIa was 77 mcg/kg (46-88), and the median dose of 4F-PCC was 31 IU/kg (24-43). The incidences of thrombotic complications were 8% in the 4F-PCC group and 30% in the rFVIIa group (adjusted p = 0.023). No difference was reported between the groups regarding chest tube output on days 1 and 2 or transfusion of blood products. Using a sensitivity analysis with propensity matching, the incidence of thrombosis was 10% in the 4F-PCC group (n = 38), and 31% in the rFVIIa group (n = 39) (p = 0.036). No difference was reported in terms of bleeding or transfusion. CONCLUSIONS: This retrospective study suggested that the administration of rFVIIa was associated with a higher risk of thrombotic complications when compared to 4F-PCC, without benefits in terms of bleeding and transfusions.

Parental holding of infants improves haemodynamics in the cardiac ICU.

We performed a single-centre, retrospective study to assess physiologic changes of infants in the cardiac ICU while being held by their parent. Continuous data streaming of vital signs were collected for infants included in the study from January 2021 to March 2022. Demographic and clinical characteristics were collected from the electronic medical record. The physiologic streaming data were analysed using mixed-effects models to account for repeated measures and quantify the effect of parental holding. Comparison analysis was also performed controlling for intubation, pre-operative versus post-operative status, and whether the holding was skin-to-skin or not. Ninety-five patients with complete physiologic data were included in the study. There were no immediate adverse events associated with holding. Heart rate decreased during the response time compared to its baseline value (p = 0.01), and this decrease was more pronounced for the non-intubated and pre-operative patients. The near-infrared spectroscopy-based venous saturation increased overall (p = 0.02) in patients while being held. We conclude that parental holding of infants in the cardiac ICU can be safely accomplished, and the haemodynamic and oximetric profile during the holding is favourable compared to the infants' baseline prior to holding.

Markov model for detection of ECG instability prior to cardiac arrest in single-ventricle patients.

OBJECTIVES: Assess the degree of instability in the electrocardiogram (ECG) waveform in patients with single-ventricle physiology before a cardiac arrest and compare them with similar patients who did not experience a cardiac arrest. METHODS: Retrospective control study in patients with single-ventricle physiology who underwent Norwood, Blalock-Taussig shunt, pulmonary artery band, and aortic arch repair from 2013 to 2018. Electronic medical records were obtained for all included patients. For each subject, 6 h of ECG data were analyzed. In the arrest group, the end of the sixth hour coincides with the cardiac arrest. In the control group, the 6-h windows were randomly selected. We used a Markov chain framework and the likelihood ratio test to measure the degree of ECG instability and to classify the arrest and control groups. RESULTS: The study dataset consists of 38 cardiac arrest events and 67 control events. Our Markov model was able to classify the arrest and control groups based on the ECG instability with an ROC AUC of 82% at the hour preceding the cardiac arrests. CONCLUSION: We designed a method using the Markov chain framework to measure the level of instability in the beat-to-beat ECG morphology. Furthermore, we were able to show that the Markov model performed well to distinguish patients in the arrest group compared to the control group.

Fluid Overload and AKI After the Norwood Operation: The Correlation and Characterization of Routine Clinical Markers.

The purpose of this study was to determine the correlation of different methods of assessing fluid overload and determine which metrics are associated with development of acute kidney injury (AKI) in the period immediately following Norwood palliation. This was a retrospective single-center study of Norwood patients from January 2011 through January 2021. AKI was defined using the Kidney Disease Improving Global Outcomes (KDIGO). Patients were separated into two groups: those with AKI and those without. A logistic regression analysis was conducted with AKI at any point in the study period as the dependent variable and clinical and laboratory data as independent variables. Analysis was conducted as a stepwise regression. The coefficients from the logistic regression were then used to develop a cumulative AKI risk score. Spearman correlations were conducted to analyze the correlation of fluid markers. 116 patients were included, and 49 (42.4%) developed AKI. The duration of open chest, duration of mechanical ventilation, need for dialysis, need for extracorporeal membrane oxygenation, and inpatient mortality were associated with AKI (p ≤ 0.05). Stepwise logistic regression demonstrated the following significant independent associations AKI: age at Norwood in days (p < 0.01), blood urea nitrogen (p < 0.01), central venous pressure (p = 0.04), and renal oxygen extraction ratio (p < 0.01). The area under the receiver operating characteristic curve for the logistic regression was 0.74. The fluid markers had weak R-value. Urea, central venous pressure, and renal oxygen extraction ratio are associated with AKI after the Norwood operation. Common clinical metrics used to assess fluid overload are poorly correlated with each other for postoperative Norwood patients.

The use of neutrophil-lymphocyte ratio for the prediction of refractory disease and coronary artery lesions in patients with Kawasaki disease.

BACKGROUND: Kawasaki disease is a vasculitis that can lead to cardiac complications, including coronary artery disease and cardiogenic shock. Various scoring systems have been developed to determine those that will be refractory to routine intravenous immunoglobulin therapy or develop coronary artery disease. The objective of this study was to determine if the neutrophil-lymphocyte ratio could predict refractory disease and coronary artery lesions in patients with Kawasaki disease. METHODS: A systematic review of the literature was performed to identify manuscripts describing comparisons of neutrophil-lymphocyte ratio between those who had refractory disease and those who did not, and between those who developed coronary artery lesions and those who did not. Mean difference was compared between groups. Areas under the curve were utilised to determine the pooled area under the curve. RESULTS: 12 studies with 5593 patients were included in the final analyses of neutrophil-lymphocyte ratio for the prediction of refractory disease. Neutrophil-lymphocyte ratio before therapy was higher in refractory disease with a mean difference of 2.55 (p < 0.01) and pooled area under the curve of 0.724. Neutrophil-lymphocyte ratio after therapy was higher in refractory disease with a mean difference of 1.42 (p < 0.01) and pooled area under the curve for of 0.803. Five studies with 1690 patients were included in the final analyses of neutrophil-lymphocyte ratio for the prediction of coronary artery lesions. Neutrophil-lymphocyte ratio before therapy was higher in coronary artery lesions with a mean difference of 0.65 (p < 0.01). CONCLUSION: The use of neutrophil-lymphocyte ratio may help physicians in the identification of patients at risk of refractory disease and coronary artery lesions in patients with Kawasaki disease.

Association of Area Deprivation Index With Severity of COVID-19 in Pediatric Patients: A Multisite Study of Racially and Ethnically Diverse Children.

Area deprivation index (ADI) is associated with the risk of severe COVID-19 in adults. However, this association has not been established in children. Information on ADI, demographics, clinical features, disease severity, and outcomes was analyzed for 3434 children with COVID-19. A multivariate logistic regression revealed that non-Hispanic Asians, extremes of weight, and higher ADI were associated with severe disease.

Pulse Oximetry and Arterial Saturation Difference in Pediatric COVID-19 Patients: Retrospective Analysis by Race.

OBJECTIVES: Pulse oximetry (Sp o2 ) may overestimate arterial oxygen saturation (Sa o2 ) in blood laboratory testing. This study aimed to assess Sp o2 -Sa o2 difference in relation to race (i.e., patient self-reporting as Black or White), occult hypoxemia, and length of stay (LOS) in pediatric patients with COVID-19. DESIGN: Single-center retrospective study in pediatric COVID-19 patients. We used multivariable linear regressions to examine the association between race and oximetry measurements and between occult hypoxemia and LOS. Oximetry bias was defined using Sp o2 and Sa o2 data according to approved comparisons. Occult hypoxemia was defined as Sp o2 greater than 92% and Sa o2 less than 88%. SETTING: Quaternary pediatric hospital. PATIENTS: Pediatric COVID-19 patients admitted to Texas Children's Hospital between May 2020 and December 2021. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: There were 2713 patients with complete physiological data in the analysis. Of the total, 61% were Black, and 39% were White. Oximetry bias was greater in Black compared with White patients ( p < 0.001), and this bias increased as the oxygen saturations decreased ( p < 0.001). Black and White patients had a 12% and 4% prevalence of occult hypoxemia, respectively ( p < 0.001). LOS was not associated with oximetry bias or occult hypoxemia once controlled for the level of support (intensive care, respiratory, circulatory). CONCLUSIONS: We found an oximetry bias in the measurement of Sp o2 with respect to Sa o2 in symptomatic hospitalized pediatric patients with the diagnosis of COVID-19. Furthermore, race is related to an increased oximetry bias. However, we did not find a relationship between oximetry bias and the LOS in the hospital in this cohort of patients.

Physiologic profile associated with severe multisystem inflammatory syndrome in children: a retrospective study.

OBJECTIVE: The purpose of this study was to describe the clinical presentation and physiologic profile of individuals with varying degrees of severity of multisystem inflammatory syndrome in children (MIS-C). METHODS: We performed a retrospective study of children diagnosed with MIS-C admitted to a single quaternary children's hospital from May 2020 to April 2021. We created an MIS-C severity score using the following parameters: hospital admission status (e.g., floor vs intensive care unit), need for inotropic or vasoactive medications, and need for mechanical ventilation. Univariate and multivariate analyses were performed to associate risk factors corresponding to the MIS-C severity score. RESULTS: The study included 152 children who were followed for 14 days post hospital admission. A stepwise forward selection process identified seven physiologic variables associated with "severe" MIS-C according to a logistic regression. Specifically, a combination of elevated creatinine (p = 0.013), international normalized ratio (p = 0.002), brain natriuretic peptide (p = 0.001), white blood cell count (p = 0.009), ferritin (p = 0.041), respiratory rate (p = 0.047), and decreased albumin (p = 0.047) led to an excellent discrimination between mild versus severe MIS-C (AUC = 0.915). CONCLUSION: This study derived a physiologic profile associated with the stratification of MIS-C severity. IMPACT: Based on a cohort of 152 individuals diagnosed with MIS-C, this study derived a nomenclature that stratifies the severity of MIS-C. Investigated demographic, presentational vital signs, and blood analytes associated with severity of illness. Identification of a multivariate physiologic profile that strongly associates with MIS-C severity. This model allows the care team to recognize patients likely to require a higher level of intensive care.

The effect of clinical and haemodynamic variables on post-operative length of stay immediately upon admission after biventricular repair with Yasui operation following an earlier Norwood operation.

BACKGROUND: There are a variety of approaches to biventricular repair in neonates and infants with adequately sized ventricles and left-sided obstruction in the presence of a ventricular septal defect. Those who undergo this in a staged manner initially undergo a Norwood procedure followed by a ventricular septal defect closure such that the neo-aorta is entirely committed to the left ventricle and placement of a right ventricular to pulmonary artery conduit (Yasui operation). This study aimed to determine clinical and haemodynamic factors upon paediatric cardiac ICU admission immediately after the two-stage Yasui operation that was associated with post-operative length of stay. METHODS: This was a retrospective review of patients who underwent the Yasui procedure after the initial Norwood operation between 1 January 2011 and 31 December 2020. Patients with complete data on admission were identified and analysed using Bayesian regression analysis. RESULTS: A total of 15 patients were included. The median age was 9.0 months and post-operative length of stay was 6days. Bayesian regression analysis demonstrated that age, weight, heart rate, mean arterial blood pressure, central venous pressure, pulse oximetry, cerebral near infrared spectroscopy, renal near infrared spectroscopy, pH, pCO2, ionised calcium, and serum lactate were all associated with post-operative length of stay. CONCLUSION: Discrete clinical and haemodynamic factors upon paediatric cardiac ICU admission after staged Yasui completion are associated with post-operative length of stay. Clinical target ranges can be developed and seem consistent with the notion that greater systemic oxygen delivery is associated with lower post-operative length of stay.

Descriptors of Failed Extubation in Norwood Patients Using Physiologic Data Streaming.

The objective of this study is to evaluate the utility of high-frequency physiologic data during the extubation process and other clinical variables for describing the physiologic profile of extubation failure in neonates with hypoplastic left heart syndrome (HLHS) post-Norwood procedure. This is a single-center, retrospective analysis. Extubation events were collected from January 2016 until July 2021. Extubation failure was defined as the need for re-intubation within 48 h of extubation. The data included streaming heart rate, respiratory rate, blood pressure, arterial oxygen saturation, and cerebral/renal near-infrared spectroscopy (NIRS). The most recent blood laboratory results before extubation were also included. These markers, demographics, clinical characteristics, and ventilatory settings were compared between successful and failed extubations. The analysis included 311 extubations. The extubation failure rate was 10%. According to univariable analyses, failed extubations were preceded by higher respiratory rates (p = 0.029), lower end-tidal CO2 (p = 0.009), lower pH (p = 0.043), lower serum bicarbonate (p = 0.030), and lower partial pressure of O2 (p = 0.022). In the first 10 min after extubation, the failed events were characterized by lower arterial (p = 0.028) and cerebral NIRS (p = 0.018) saturations. Failed events were associated with persistently lower values for cerebral NIRS 2 h post-extubation (p = 0.027). In multivariable analysis, vocal cord anomaly, cerebral NIRS at 10 min post-extubation, renal NIRS at pre-extubation and post-extubation, and end-tidal CO2 at pre-extubation remained as significant co-variables. Oximetric indices before, in the 10 min immediately after, and 2 h after extubation and vocal cords paralysis are associated with failed extubation events in patients with parallel circulation.

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.

Noninvasive Respiratory Support Does Not Prevent Extubation Failure in High-Risk Norwood Patients.

This study aims to determine whether bilevel positive airway pressure (BiPAP) and continuous positive airway pressure (CPAP) effectively mitigate the risk of extubation failure in children status post-Norwood procedure. DESIGN: Single-center, retrospective analysis. Extubation events were collected from January 2015 to July 2021. Extubation failure was defined as the need for reintubation within 48 hours of extubation. Demographics, clinical characteristics, and ventilatory settings were compared between successful and failed extubations. SETTING: Pediatric cardiovascular ICU. PATIENTS: Neonates following Norwood procedure. INTERVENTIONS: Extubation following the Norwood procedure. MEASUREMENTS AND MAIN RESULTS: The analysis included 311 extubations. Extubation failure occurred in 31 (10%) extubation attempts within the first 48 hours. On univariate analysis, higher rate of extubation failure was observed when patients were extubated to CPAP/BiPAP relative to patients who were extubated to either high-flow nasal cannula (HFNC) or nasal cannula (NC) (16% vs 7.8%; p = 0.027). On multivariable analysis, the presence of vocal cord anomaly (odds ratio, 3.08; p = 0.005) and lower pre-extubation end-tidal co2 (odds ratio, 0.91; p = 0.006) were simultaneously associated with extubation failure while also controlling for the post-extubation respiratory support (CPAP/BiPAP/HFNC vs NC). CONCLUSIONS: Clinicians should not rely on CPAP or BiPAP as the only supportive measure for a patient at increased risk of extubation failure. CPAP or BiPAP do not mitigate the risk of extubation failure in the Norwood patients. A multisite study is needed to generalize these conclusions.

The acute influence of vasopressin on hemodynamic status and tissue oxygenation following the Norwood procedure.

Objectives: Arginine vasopressin (AVP) is used to treat hypotension. Because AVP increases blood pressure by increasing systemic vascular resistance, it may have an adverse effect on tissue oxygenation following the Norwood procedure. Methods: Retrospective analysis of continuously captured hemodynamic data of neonates receiving AVP following the Norwood procedure. Results: We studied 64 neonates exposed to AVP within 7 days after the Norwood procedure. For the entire group, AVP significantly increased mean blood pressure (2.5 ± 6.3) and cerebral and renal oxygen extraction ratios (4.1% ± 9.6% and 2.0% ± 4.7%, respectively; P < .001 for all values). In the right ventricle to pulmonary artery shunt cohort, AVP significantly increased blood pressure, arterial oxygen saturation (1.4% ± 3.8%; P = .011), pulmonary to systemic perfusion ratio (0.2 ± 0.4; P = .017), and cerebral and renal oxygen extraction ratios (4.6% ± 8.7%; P = .010% and 4.7% ± 9.4%; P = .014, respectively). The Blalock-Taussig shunt cohort experienced a less significant vasopressor response and no change in arterial oxygen saturation, pulmonary to systemic perfusion ratio, or cerebral and renal oxygen extraction ratios. Conclusions: The right ventricle to pulmonary artery shunt cohort experienced a significant vasopressor response to AVP that was associated with a significant increase in pulmonary perfusion and decrease in cerebral and renal perfusion, whereas the Blalock-Taussig shunt cohort experienced a less significant vasopressor response and no change in pulmonary or systemic perfusion. The influence of AVP on tissue oxygenation following the Norwood procedure may have clinical implications that require further study.

Social and Demographic Disparities in the Severity of Multisystem Inflammatory Syndrome in Children.

Social constructs are known risk factors for multisystem inflammatory syndrome in children. A review of 206 patients demonstrated that children who were non-Hispanic Black, over the age of 12 years or living in a disadvantaged neighborhood associated with severe multisystem inflammatory syndrome in children (intensive care unit admission, intubation and/or vasopressor use).

Quantification of electrocardiogram instability prior to cardiac arrest in patients with single-ventricle physiology.

OBJECTIVE: To quantify the instability measured in the electrocardiogram (ECG) waveform in patients with single-ventricle physiology before a cardiac arrest and compare with similar patients who did not have a cardiac arrest. METHODS: We measure the instability in the ECG morphology using variance, entropy, and decorrelation of polynomial fit coefficients of the beat-to-beat segmented data. These three metrics quantify the spread of the ECG morphology, the lack of beat-to-beat periodicity and the lack of predictability, respectively. For each subject, 3 h of ECG data were analyzed. In the arrest group, the end of the third hour coincides with the cardiac arrest. In the control group, the 3-h windows were randomly selected. RESULTS: The study dataset consists of 38 cardiac arrest events and 67 control events. In the hour prior to the cardiac arrest, the variance, entropy, and decorrelation of the polynomial fit coefficients were higher in the arrest group than in the control group (p = 0.003, p = 0.009, and p = 0.035, respectively). For the second and third hours prior to the arrests, the differences in variance, entropy, and decorrelation between the arrest and control groups lost statistical significance. Using these metrics of instability as predictive features in a support vector machine algorithm, we found an area under the receiver operating characteristic curve of 0.8 to distinguish the arrest event from the control events. CONCLUSION: By taking a holistic assessment of the ECG waveform in patients with single-ventricle physiology to measure the instability in its beat-to-beat morphology, the ECG waveform variance, entropy, and decorrelation are found to be statistically different in the patients who arrested compared with patients in the control group.

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.