Pediatric Cardiac Surgery Patients Research Articles

小児心臓手術後におけるデクスメデトミジンと抑肝散併用療法の鎮静効果

Objectives: The study was conducted to compare the combined effect of dexmedetomidine (DEX) and oral or suppository Yokukansan (YKS) on sedation after cardiac surgery in pediatric patients. Methods: Eighteen postoperative patients were divided into three groups according to YKS combined with continued administration of DEX: non-YKS (NY) group, gastric tube (oral) YKS (GY) group, and intrarectal suppository YKS (RY) group. YKS was administered at a dose of 0.1 g/kg every four hours. The sedation level was evaluated using Richmond Agitation-Sedation Scale and Behavioural Observational Pain Scale, and ketamine was administered for patients with scores ≥2 in either scales. The total dose of ketamine administered per body weight was used to define the sedative effect. Results: The ketamine dose (median) was 1.5, 1.0, and 0 mg/kg/day in NY, GY, and RY groups, respectively. Compared with the NY group, the GY group used less ketamine but the difference was not significant (P=0.49) and the RY group used a significantly lower dose (P=0.03). Conclusions: The combination of DEX and suppository YKS was effective for sedation in children after cardiac surgery, while DEX combined with gastric tube (oral) YKS was not sufficient in efficacy.

Monitoring Microcirculatory Blood Flow during Cardiopulmonary Bypass in Paediatric Cardiac Surgery Patients as a Predictor for Anaerobic Metabolism.

Improving tissue oxygenation is one of most important tasks in management of low cardiac output. Central venous oxygen saturation (ScvO2) and lactate are established criteria for monitoring the adequacy of tissue oxygenation. The venous-to-arterial carbon dioxide difference [P(v-a)CO2] is inversely associated with cardiac output. To study the use of P(v-a)CO2/C(a-v)O2 ratio as a marker of low cardiac output during Cardiopulmonary Bypass (CPB) in paediatric cardiac surgical patients. The present study was a prospective observational study conducted over a period of nine months from 1st August 2015 to 30th April 2016. A total of 110 children were enrolled, who underwent CPB during cardiac surgery. The CPB time, Mean Arterial Pressure (MAP), flow rate, cross clamp time, were recorded for all the patients as well as Arterial Blood Gas (ABG) and Venous Blood Gas (VBG) were checked at four different points of time: 1) Before CPB, 2) 10 minutes after initiation of CPB, 3) 30 minutes on CPB and 4) off CPB. The results indicated that Receiver Operating Characteristic curve (ROC curve) at 30 minute of CPB time P(v-a)CO2/C(a-v)O2 was more specific and sensitive than lactate to detect anaerobic metabolism. Decrease platelet count was significant on second postoperative day. The present study suggests the use of P(v-a)CO2/C(a-v)O2 ratio as a marker to detect low flow on CPB. Our study was single centric and with a small size, studies involving large population and multiple centers are required to support the recent findings.

Does heart-type fatty acid-binding protein predict clinical outcomes after pediatric cardiac surgery?

Introduction:The early identification of vulnerable pediatric cardiac surgery patients can help clinicians provide them with timely support. Heart-type fatty acid-binding protein. (H-FABP) is an early biomarker of myocardial injury in acute myocardial infarction in adults. In this study, we evaluated the correlations between postoperative H-FABP, creatine kinase-myocardial band (CK-MB), troponin-I, total bypass time, and clinical outcomes.Methods:In 32 pediatric patients that underwent ventricular septal defect. closure we measured H-FABP, troponin-I and CK-MB preoperatively and 1, 3, and 6 h after aortic declamping. Spearman's Rho correlations were calculated between laboratory and clinical parameters including inotropic support duration, aortic cross-clamp time, total bypass time, ventilation-weaning-time, and total Intensive Care Unit stay.Results:H-FABP, CK-MB, troponin-I, and total bypass time have a similarly weak to moderate correlation with clinical outcome measures.Conclusions:The predictive value of H-FABP for clinical outcome is not stronger than that of CK-MB, Troponin-I, or bypass times.

Perioperative Brain Natriuretic Peptide in Pediatric Cardiac Surgery Patients: Its Association With Postoperative Outcomes

The aim of this study was to investigate the relationship between perioperative brain natriuretic peptide levels and the incidence of postoperative serious adverse events (SAEs) in pediatric cardiac patients. A prospective observational study. A single-institution university hospital. Children under 15 years old who underwent cardiac surgery that required cardiopulmonary bypass from December 21, 2012 to February 26, 2014. The Risk Adjustment for Congenital Heart Surgery 1 category less than 1 was excluded. Brain natriuretic peptide (BNP) levels were measured preoperatively (BNPpre) and on postoperative day 1 (BNPPOD1) and postoperative day 3 (BNPPOD3). Primary outcome was the incidence of postoperative SAEs; (1) death in the intensive care unit, (2) requirement of extracorporeal membrane oxygenation, (3) cardiac arrest, and (4) requirement of reoperation for hemodynamic instability. The authors included 71 patients in this study. There were 8 patients (11%) who had at least 1 SAE. Median preoperative BNP level in patients with SAEs was significantly higher than in those without SAEs (1,541 pg/mL [IQR: 121-5,962] v 122 pg/mL [QR: 34-342], p = 0.01). From the receiver operating characteristic curve of BNPpre for the incidence of SAEs, an area under the curve was 0.77 (95%CI 0.55-0.91). The best cutoff BNPpre number was 1,000 pg/mL. From the multivariate logistic regression model, BNPpre>1,000 pg/mL was associated independently with risk of SAEs (adjusted odds ratio = 8.5, 95% CI [1.3, 59.3], p = 0.02). In conclusion, the authors' study showed that increased preoperative brain natriuretic peptide concentration, especially a concentration of more than 1,000 pg/mL, was associated with risk of SAEs in pediatric cardiac surgery patients.

Red Blood Cell Transfusion in the Postoperative Care of Pediatric Cardiac Surgery: Survey on Stated Practice

The optimal red blood cell transfusion threshold for postoperative pediatric cardiac surgery patients is unknown. This study describes the stated red blood cell transfusion practice of physicians who treat postoperative pediatric cardiac surgery patients in intensive care units. A scenario-based survey was sent to physicians involved in postoperative intensive care of pediatric cardiac surgery patients in all Canadian centers that perform such surgery. Respondents reported their red blood cell transfusion practice in four postoperative scenarios: acyanotic or cyanotic cardiac lesion, in a neonate or an infant. In part A of each scenario, the patient was critically ill, but stabilized; in part B, the patient became unstable. Response rate was 58% (71 of 123), with 45 respondents indicating direct involvement in postoperative intensive care. There was a wide variability in stated transfusion threshold, ranging from <7.0-14.0g/dL for stabilized cases. There was no significant difference between neonates and infants in stated transfusion threshold. The mean hemoglobin level below which respondents would transfuse a stabilized patient was 9g/dL for acyanotic and 11.2g/dL for cyanotic patients, a statistically significant difference (2.2±0.9g/dL, p<0.001). All clinical determinants of instability significantly increased transfusion threshold. Hemodynamic instability increased transfusion threshold by 2.3±1.3g/dL in acyanotic patients and by 1.3±1.1g/dL in cyanotic patients. Cyanotic lesion and clinical instability, but not patient age, increased stated red blood cell transfusion threshold. Significant variation in reported red blood cell transfusion practice exists among physicians treating pediatric patients in intensive care following cardiac surgery.

Predictors of Early Extubation After Pediatric Cardiac Surgery: A Single-Center Prospective Observational Study.

This prospective, observational, single-center study aimed to determine the perioperative predictors of early extubation (<24h after cardiac surgery) in a cohort of children undergoing cardiac surgery. Children aged between 1month and 18years who were consecutively admitted to pediatric intensive care unit after cardiac surgery for congenital heart disease between January 2012 and June 2014. Ninety-nine patients were qualified for inclusion during the study period. The median duration of mechanical ventilation was 20h (range 1-480), and 64 patients were extubated within 24h. Four of them failed the initial attempt at extubation, and the success rate of early extubation was 60.6%. Older patient age (p=.009), greater body weight (p=.009), absence of preoperative pulmonary hypertension (p=.044), lower RACHS-1 category (OR, 3.8; 95% CI 1.35-10.7; p<.05), shorter cardiopulmonary bypass (p=.008) and cross-clamp (p=.022) times, lower PRISM III-24 (p<.05) and PELOD (p<.05) scores, lower inotropic score (p<.05) and vasoactive-inotropic score (p<.05), and lower number of organ failures (OR, 2.26; 95% CI 1.30-3.92; p<.05) were associated with early extubation. Our study establishes that early extubation can be accomplished within the first 24h after surgery in low- to medium-risk pediatric cardiac surgery patients, especially in older ones undergoing low-complexity procedures. A large prospective multiple institution trial is necessary to identify the predictors and benefits of early extubation and to facilitate defined guidelines for early extubation.

Perioperative monitoring of platelet function in paediatric cardiac surgery by thromboelastometry, or platelet aggregometry?

BackgroundImpaired platelet function increases the risk of bleeding complications in cardiac surgery. Reliable assessment of platelet function can improve treatment. We investigated whether thromboelastometry detects clinically significant preoperative, perioperative, and postoperative adenosine diphosphate (ADP)-dependent platelet dysfunction in paediatric cardiac surgery patients. MethodsFifty-seven children were included in a single-centre prospective observational study. Clot formation (modified rotational thromboelastometry with heparinase, HEPTEM) and platelet aggregation (multiple electrode aggregometry) were analysed at five time points before, during, and after surgery. The accuracy of thromboelastometric indices of platelet function [maximal clot firmness (MCF) and clot formation time (CFT)] to detect ADP-dependent platelet dysfunction (defined as ADP-induced aggregation ≤30 units) was calculated with receiver operating characteristics analysis, which also identified optimal cut-off levels. Positive and negative predictive values for the identified cut-off levels (CFT≥166 s; MCF≤43 mm) to detect platelet function were determined. ResultsThe MCF and CFT were highly accurate in predicting platelet dysfunction during cardiopulmonary bypass [CPB; area under the aggregation curve 0.89 (95% confidence interval 0.80–0.97) and 0.86 (0.77–0.96), respectively] but not immediately after CPB [0.64 (0.48–0.79) and 0.67 (0.52–0.82), respectively] or on arrival at the intensive care unit [0.53 (0.37–0.69) and 0.60 (0.44–0.77), respectively]. The positive and negative predictive values were acceptable during CPB (87 and 67%, respectively, for MCF≤43 mm; 80 and 100% for CFT≥166 s) but markedly lower after surgery. ConclusionIn paediatric cardiac surgery, thromboelastometry has acceptable ability to detect ADP-dependent platelet dysfunction during, but not after, CPB.

Pragmatic pharmacology: population pharmacokinetic analysis of fentanyl using remnant samples from children after cardiac surgery.

One barrier contributing to the lack of pharmacokinetic (PK) data in paediatric populations is the need for serial sampling. Analysis of clinically obtained specimens and data may overcome this barrier. To add evidence for the feasibility of this approach, we sought to determine PK parameters for fentanyl in children after cardiac surgery using specimens and data generated in the course of clinical care, without collecting additional blood samples. We measured fentanyl concentrations in plasma from leftover clinically-obtained specimens in 130 paediatric cardiac surgery patients and successfully generated a PK dataset using drug dosing data extracted from electronic medical records. Using a population PK approach, we estimated PK parameters for this population, assessed model goodness-of-fit and internal model validation, and performed subset data analyses. Through simulation studies, we compared predicted fentanyl concentrations using model-driven weight-adjusted per kg vs. fixed per kg fentanyl dosing. Fentanyl clearance for a 6.4 kg child, the median weight in our cohort, is 5.7 l h(-1) (2.2-9.2 l h(-1) ), similar to values found in prior formal PK studies. Model assessment and subset analyses indicated the model adequately fit the data. Of the covariates studied, only weight significantly impacted fentanyl kinetics, but substantial inter-individual variability remained. In simulation studies, model-driven weight-adjusted per kg fentanyl dosing led to more consistent therapeutic fentanyl concentrations than fixed per kg dosing. We show here that population PK modelling using sparse remnant samples and electronic medical records data provides a powerful tool for assessment of drug kinetics and generation of individualized dosing regimens.

Sustainability of protocolized handover of pediatric cardiac surgery patients to the intensive care unit.

Transfer of patient care among clinicians (handovers) is a common source of medical errors. While the immediate efficacy of these initiatives is well documented, sustainability of practice changes that results in better processes of care is largely understudied. The objective of the current investigation was to evaluate the sustainability of a protocolized handover process in pediatric patients from the operating room after cardiac surgery to the intensive care unit. This was a prospective study with direct observation assessment of handover performance conducted in the cardiac ICU (CICU) of a free-standing, tertiary care children's hospital in the United States. Patient transitions from the operating room to the CICU, including the verbal handoff, were directly observed by a single independent observer in all phases of the study. A checklist of key elements identified errors classified as: (1) technical, (2) information omissions, and (3) realized errors. Total number of errors was compared across the different times of the study (preintervention, postintervention, and the current sustainability phase). A total of 119 handovers were studied: 41 preintervention, 38 postintervention, and 40 in the current sustainability phase. The median [Interquartile range (IQR)] number of technical errors was significantly reduced in the sustainability phase compared to the preintervention and postintervention phase, 2 (1-3), 6 (5-7), and 2.5 (2-4), respectively P = 0.0001. Similarly, the median (IQR) number of verbal information omissions was also significantly reduced in the sustainability phase compared to the preintervention and postintervention phases, 1 (1-1), 4 (3-5) and 2 (1-3), respectively. We demonstrate sustainability of an improved handover process using a checklist in children being transferred to the intensive care unit after cardiac surgery. Standardized handover processes can be a sustainable strategy to improve patient safety after pediatric cardiac surgery.

Storage duration of transfused red blood cells is not significantly associated with postoperative adverse events in pediatric cardiac surgery patients

The aim of this study was to evaluate the association of storage duration of transfused red blood cells with the risk of postoperative serious adverse events in pediatric cardiac surgery patients. We studied 517 patients and found that 22 patients (4.3%) had at least one serious adverse event. The maximum and mean storage duration of transfused red blood cells did not differ significantly between patients with and without serious adverse events (maximum, p = 0.89; mean, p = 0.81). In our study of pediatric cardiac surgery patients, the storage duration of transfused red blood cells was not significantly associated with the risk of serious adverse events.

Correlation between passive leg raising manoeuvre and fluid challenge in paediatric cardiac surgery patients by the use of impedance cardiography

Correlation between passive leg raising manoeuvre and fluid challenge in paediatric cardiac surgery patients by the use of impedance cardiography

Monitoring the correlation between passive leg-raising maneuver and fluid challenge in pediatric cardiac surgery patients using impedance cardiography

Aim The aim of the study was to highlight the effectiveness of passive leg-raising maneuver as a predictor of fluid responsiveness in pediatric patients following cardiac surgery and to determine the parameter that we can depend on to assess its responsiveness. Patients and methods This prospective randomized study was performed in the ICU. Forty pediatric patients aged 2-7 years with a noncyanotic cardiac defect scheduled for elective corrective cardiac surgery under cardiopulmonary bypass (CPB) support were included if they needed fluid challenge (FC) in the early postoperative period (10 ml/kg normal saline infusion). Hemodynamic parameters [heart rate, mean blood pressure, stroke volume (SV), and cardiac index (CI)] were assessed at baseline, after passive leg raising (PLR), at baseline again, and after FC. Statistical analysis A comparison of pre-PLR and post-PLR hemodynamic parameters and those before and after FC was made using the paired Student's t-test, whereas a comparison after passive leg raising (PLR) and FC was made using the unpaired Student's t-test. The hemodynamic parameters after PLR and its relation to the responses to fluid administration were analyzed using diagnostic validity tests and the χ2 -test. Results The increase in SV and CI with PLR is significantly correlated with the response to fluid administration. An increase in CI by 10% or more due to PLR predicted preload-dependent status with a sensitivity of 65% and a specificity of 75%, whereas an increase in SV by more than 10% due to PLR predicted preload-dependent status with a sensitivity of 42.1% and a specificity of 85.7%. Conclusion The PLR maneuver is a reliable noninvasive method that can predict volume responsiveness in post-cardiac-surgery pediatric patients. Both SV and CI can be used as predictors of fluid responsiveness, although CI is a more accurate.

Nursing Care of Pediatric Cardiac Surgery Patients With Extracorporeal Membrane Oxygenation Support

Nursing Care of Pediatric Cardiac Surgery Patients With Extracorporeal Membrane Oxygenation Support

Decreased Hemolysis of Red Cells Washed with Plasma-Lyte As Compared with 0.9% Sodium Chloride

Introduction -Washed red blood cell (RBC) and platelet transfusions have been a valuable therapeutic option for patients with repeated or severe allergic or febrile reactions. Recent data from randomized and observational clinical trials demonstrate that washed transfusions reduce inflammatory and immunologic complications, including recurrence of acute leukemia, death after coronary surgery, elevations of IL-6 and C-reactive protein after pediatric cardiac surgery, and transfusion related acute lung injury and transfusion associated cardiac overload. However, washing of RBCs may not be completely benign. Increased hemolysis may occur in vitro. Washing of RBCs stored for longer periods (>28 days) is associated with increased morbidity in pediatric cardiac surgery patients receiving massive transfusions of older RBCs. Current washing techniques and dilution of RBCs for transfusion employ 0.9% normal saline (NS) which is both hypertonic and acidic. We evaluated whether use of a more physiologic solution, Plasma-Lyte, causes less damage to RBCs than use of NS.Methods -We employed RBC units (n=15) collected for, but not suitable for clinical transfusion. Median storage age was 19 days (range 10-39 days). Each donor unit (11 AS-1, 3 AS-3 and 1 CPD-A1) was split in two using aseptic technique, and washed with either a liter of NS or Plasma-Lyte employing a standard clinical protocol on a Terumo 2991. Each half was resuspended in 20 ml of washing solution. Aliquots (12 ml) were removed prior to and immediately after washing, and after 24, 48 and 72 hours of storage at 1-6¡ C. These aliquots were immediately centrifuged (15 min at 4,300 x g) and the supernatant stored at -80¡ C. Hemoglobin and heme in the supernatant were quantitated using QuantiChrom kits. All comparisons were by Wilcoxon matched pairs non-parametric tests.Results -Supernatants immediately after washing had similar mean free hemoglobin (pre = 160 mg/dl ± 80 [SEM]; post = 66 ± 12 for NS and 58 ± 10 for Plasma-Lyte) and heme (pre = 92 µM ± 46; post = 36 ± 8 for NS and 33 ± 7 for Plasma-Lyte ). However, by 24 hours of storage after washing (the current limit for clinical use), supernatant heme and hemoglobin were significantly greater by about 50% in RBCs stored in NS (87 µM ± 22 and 151 mg/dl ± 36) as compared to Plasma-Lyte (59 µM ± 21 and 108 mg/dl ± 36; p = 0.014 and 0.02). These changes accelerated during subsequent storage (see figure for heme levels-differences in hemoglobin were comparable). Prolonged storage after NS washing predisposed to greater hemolysis than did Plasma-Lyte washing. Supernatant heme levels at 72 hours post washing increased from early (10-18 days; n=5) to late (31-39 days; n=5) storage by a mean of 61% in Plasma-Lyte washed RBCs (p=0.26) compared with 200% in NS washed RBCs (p=0.016)Conclusions -RBCs stored for 10-39 days and then washed with Plasma-Lyte experience strikingly less hemolysis. Whether such differences would occur in vivo is not known, and the clinical implications are yet to be determined. Circulating free heme and hemoglobin levels have been associated with thrombosis in animal models, transfused patients and patients with sickle cell disease. NS, as opposed to Plasma-Lyte, has been linked to increased renal injury and mortality in animal models and patients. We speculate that hemolysis may be a contributing cause. Our results indicate that RBC washing with Plasma-Lyte is a superior approach and potentially safer than NS. These findings also suggest the hypothesis for further investigation of whether NS is truly a suitable diluent for RBC transfusion, and whether NS is the safest choice when crystalloid is indicated for volume replacement or apheresis. Plasma-Lyte washing might also facilitate increasing the storage period of washed RBCs. [Display omitted] DisclosuresOff Label Use: See Dr. Blumberg's disclosure. Blumberg:Biomet: Consultancy; Terumo: Consultancy.

Pharmacological Manipulation of Peripheral Vascular Resistance in Special Clinical Situations after Pediatric Cardiac Surgery.

Pediatric cardiac surgery patients commonly suffer from alterations in vascular tone in the early post-operative period. Pharmacologic manipulation of systemic vascular resistance (SVR) can be complex in a variety of special patient situations including extremes of age, presence of left sided valvar lesions and the use of mechanical circulatory support. Familiarity with how these special circumstances alter SVR and the response to pharmacologic intervention will allow for tailored therapy and hopefully, optimized outcomes. This article addresses the eighth topic of the special issue entitled "Pharmacologic strategies with afterload reduction in low cardiac output syndrome after pediatric cardiac surgery".

Abstract 17511: Microvesicles and MicroRNAs as Marker of Acute Kidney Injury After Cardiac Surgery in Children

Introduction: AKI is very common in paediatric cardiac surgery patients. The diagnosis relies on changes in serum creatinine and urine output, which lack specificity and sensitivity especially in newborns and premature infants. Diagnostic changes also occur late in the injury phase when interventions have limited effectiveness. Microvesicles (MV) are small particles (&lt;1μm) in plasma that often contain miRNA. Their levels have been shown to be altered in animal models of AKI where they regulate injury responses. Hypothesis: MV and associated miRNA provide specific and early-detection markers for AKI and a tool to investigate AKI pathogenesis. Methods: Study subjects were 24 children (&lt;17 yrs), undergoing cardiac surgery with cardiopulmonary bypass (CPB) without pre-existing inflammatory state, AKI or extracorporeal life support. AKI was diagnosed following the KDIGO definition. Blood and urine samples were collected pre-operatively and at 6 and 24 hours. Cytokines were measured on a MAGPIX platform. Leukocyte and platelets activation, and MV derivation was assessed by flow cytometry and NanoSight device. miRNAs were isolated from MV preps and analyzed by RT-PCR using Applied Biosystems kits. Results: AKI was diagnosed in 14 patients and was confirmed by urinary NGAL increase at 6 hours after the operation (25±3.45 ng/ml vs 10.44±2.9 ng/ml; p 0.006). Patients with AKI were younger, underwent longer CPB, received higher volumes of red blood cells, and required higher inotrope support (Table). AKI subjects had increased levels of monocyte and B1-integrin MV. That correlated well with IL-8 and MCP-3 levels and monocyte activation. These changes were also reflected in miRNA profile in both groups. Conclusions: MV and miRNA could potentially serve as early AKI markers in children and their analysis reveals mechanistic parallels with adults.

Fluid Status Assessment and Management During the Perioperative Phase in Pediatric Cardiac Surgery Patients.

PERIOPERATIVE FLUID MANAGEMENT has been studied extensively, especially in noncardiac surgery populations, and hypovolemia and hypervolemia clearly have been identified as major contributors of morbidity and mortality. It has been demonstrated that both hypovolemia, eventually leading to inadequate oxygen delivery (DO2), and hypervolemia, which causes tissue edema, organ dysfunction, and coagulation system alterations, are associated with increased perioperative morbidity risk that has been welldescribed as a “parabolic-U-shape” relationship. Nonetheless, to date, the optimal regimen of fluids administration still is a matter of debate, and great concerns remain about the type (colloids v crystalloids), the ideal composition, and the amount of fluids that should be administered. Whereas in low-risk patients undergoing minor surgery, “liberal” fluid administration (or “nonrestrictive”) seems to improve outcome, reducing complications and length of stay, but in high-risk and pediatric surgeries, the issue is much more complex and individualized fluid administration (goaldirected therapy [GDT]) seems to be reasonable. In cardiac surgery patients, the distribution of fluids in the intravascular or extravascular spaces depends on a number of intraoperative and postoperative factors that highly influence the pathophysiology of body fluid kinetics, including the patients’ body surface area; cardiopulmonary bypass (CPB) (starting, conducting, and weaning); CPB priming solution (volume and composition); cardioplegic solutions (volume, composition, and temperature); CPB circuits and artificial lungs; thermal management; and vasoactive and inotropic drugs. Patient age is another key factor determining different fluid kinetics during cardiac surgery. This review is the first of 2 concerning fluid management during and after adult and

Effects of acute kidney injury and chronic hypoxemia on fibroblast growth factor 23 levels in pediatric cardiac surgery patients.

Fibroblast growth factor-23 (FGF23) levels are elevated in cardiopulmonary bypass (CPB)-associated acute kidney injury (AKI); however, it is unknown how much of the circulating FGF23 is intact and bioactive. Hypoxia may induce FGF23 production, yet its impact in humans is unknown. Pediatric cardiac surgery patients have both a high incidence of CPB-associated AKI and a high prevalence of chronic hypoxemia. We assessed the effects of hypoxemia and CPB-associated AKI on C-terminal FGF23 (cFGF23) and intact FGF23 (iFGF23) levels in 32 pediatric cardiac surgery patients with normal estimated glomerular filtration rate (eGFR). Plasma cFGF23 and iFGF23 were measured preoperatively and serially postoperatively. Despite normal renal and ventricular function, preoperative cFGF23 levels were high and elevated out of proportion to iFGF23 levels. Preoperative oxygen saturation measurements correlated inversely with FGF23 levels. Preoperative cFGF23 and oxygen saturation both predicted postoperative AKI. Postoperatively, cFGF23 and iFGF23 increased by 2h postreperfusion; iFGF23 then returned to baseline, but cFGF23 remained elevated through 24 h postreperfusion. Group status (AKI vs. non-AKI) modified the effect of time on changes in iFGF23 levels but not cFGF23 levels. Preoperative cFGF23 may predict CPB-associated kidney dysfunction. Changes over time in cFGF23 and iFGF23 levels post-CPB differ. Chronic hypoxemia may affect FGF23 production in humans.

Effect of 22q11.2 deletion on bleeding and transfusion utilization in children with congenital heart disease undergoing cardiac surgery.

Postsurgical bleeding causes significant morbidity and mortality in children undergoing surgery for congenital heart defects (CHD). 22q11.2 deletion syndrome (DS) is the second most common genetic risk factor for CHD. The deleted segment of chromosome 22q11.2 encompasses the gene encoding glycoprotein (GP) Ibβ, which is required for expression of the GPIb-V-IX complex on the platelet surface, where it functions as the receptor for von Willebrand factor (VWF). Binding of GPIb-V-IX to VWF is important for platelets to initiate hemostasis. It is not known whether hemizygosity for the gene encoding GPIbβ increases the risk for bleeding following cardiac surgery for patients with 22q11.2 DS. We performed a case-control study of 91 pediatric patients who underwent cardiac surgery with cardiopulmonary bypass from 2004 to 2012 at Children's Hospital of Wisconsin. Patients with 22q11.2 DS had larger platelets and lower platelet counts, bled more excessively, and received more transfusion support with packed red blood cells in the early postoperative period relative to control patients. Presurgical genetic testing for 22q11.2 DS may help to identify a subset of pediatric cardiac surgery patients who are at increased risk for excessive bleeding and who may require more transfusion support in the postoperative period.

Evaluating the Safety of Intraoperative Antiarrhythmics in Pediatric Cardiac Surgery Patients.

Cardiac arrhythmias occurring during the intraoperative period for cardiac surgery have been associated with excess morbidity and mortality. Several antiarrhythmics have been utilized for the management of intraoperative arrhythmias. These antiarrhythmic medications can cause undesirable adverse outcomes in the intensive care setting. The incidence and treatment of adult intraoperative arrhythmias have been studied. In addition, the prevalence, risk factors, and optimal treatment of pediatric postoperative arrhythmias have also been studied. However, the literature has not been published on intraoperative antiarrhythmia treatment during pediatric cardiac surgery. The purpose of this study was to determine the safety of intraoperative antiarrhythmic medications utilized in pediatric cardiac surgery patients. This was a retrospective review of all patients who received an intraoperative antiarrhythmic in the cardiovascular operating room at Texas Children's Hospital. Patients were included if they underwent cardiovascular surgery from November 2008 to July 2013 and were excluded if antiarrhythmics were given intraoperatively for other indications (i.e., esmolol for hypertension) or if patients were older than 18 years of age. Safety of antiarrhythmic treatment was determined by the absence or presence of adverse events. Control or recurrence of the arrhythmia was analyzed as a secondary measure to help determine antiarrhythmic efficacy. A total of 45 patients were identified (53.3 % male). Patients were a median of 0.52 years at the time of surgery. Primary surgery types were tetralogy of Fallot repair (n = 6; 13.3 %) and ventricular septal defect closure (n = 5, 11.1 %). Thirty-one patients (68.9 %) had documented adverse events after the administration of antiarrhythmics. Most of these adverse events occurred after the administration of amiodarone (n = 16; 51.6 %) followed by esmolol (n = 15; 48.4 %). Fifty-one percent of the arrhythmias resolved in the operating room (n = 23), and nearly half (n = 19) of all patients were discharged home on an antiarrhythmic medication. A high incidence of adverse events was associated with intraoperative administration of antiarrhythmic medications.