Analysis of haemodynamics surrounding blood transfusions after the arterial switch operation: a pilot study utilising real-time telemetry high-frequency data capture.

BACKGROUND: Packed red blood cell transfusions occur frequently after congenital heart surgery to augment haemodynamics, with limited understanding of efficacy. The goal of this study was to analyse the hemodynamic response to packed red blood cell transfusions in a single cohort, as "proof-of-concept" utilising high-frequency data capture of real-time telemetry monitoring. METHODS: Retrospective review of patients after the arterial switch operation receiving packed red blood cell transfusions from 15 July 2020 to 15 July 2021. Hemodynamic parameters were collected from a high-frequency data capture system (SickbayTM) continuously recording vital signs from bedside monitors and analysed in 5-minute intervals up to 6 hours before, 4 hours during, and 6 hours after packed red blood cell transfusions-up to 57,600 vital signs per packed red blood cell transfusions. Variables related to oxygen balance included blood gas co-oximetry, lactate levels, near-infrared spectroscopy, and ventilator settings. Analgesic, sedative, and vasoactive infusions were also collected. RESULTS: Six patients, at 8.5[IQR:5-22] days old and weighing 3.1[IQR:2.8-3.2]kg, received transfusions following the arterial switch operation. There were 10 packed red blood cell transfusions administered with a median dose of 10[IQR:10-15]mL/kg over 169[IQR:110-190]min; at median post-operative hour 36[IQR:10-40]. Significant increases in systolic and mean arterial blood pressures by 5-12.5% at 3 hours after packed red blood cell transfusions were observed, while renal near-infrared spectroscopy increased by 6.2% post-transfusion. No significant changes in ventilation, vasoactive support, or laboratory values related to oxygen balance were observed. CONCLUSIONS: Packed red blood cell transfusions given after the arterial switch operation increased arterial blood pressure by 5-12.5% for 3 hours and renal near-infrared spectroscopy by 6.2%. High-frequency data capture systems can be leveraged to provide novel insights into the hemodynamic response to commonly used therapies such as packed red blood cell transfusions after paediatric cardiac surgery.

The effect of continuous venovenous hemodiafiltration on amino acid delivery, clearance, and removal in children.

BACKGROUND: In critically ill children with acute kidney injury (AKI), continuous kidney replacement therapy (CKRT) enables nutrition provision. The magnitude of amino acid loss during continuous venovenous hemodiafiltration (CVVHDF) is unknown and needs accurate quantification. We investigated the mass removal and clearance of amino acids in pediatric CVVHDF. METHODS: This is a prospective observational cohort study of patients receiving CVVHDF from August 2014 to January 2016 in the pediatric intensive care unit (PICU) of a tertiary children's hospital. RESULTS: Fifteen patients (40% male, median age 2.0 (IQR 0.7, 8.0) years) were enrolled. Median PICU and hospital lengths of stay were 20 (9, 59) and 36 (22, 132) days, respectively. Overall survival to discharge was 66.7%. Median daily protein prescription was 2.00 (1.25, 2.80) g/kg/day. Median daily amino acid mass removal was 299.0 (174.9, 452.0) mg/kg body weight, and median daily amino acid mass clearance was 18.2 (13.5, 27.9) ml/min/m2, resulting in a median 14.6 (8.3, 26.7) % protein loss. The rate of amino acid loss increased with increasing dialysis dose and blood flow rate. CONCLUSION: CVVHDF prescription and related amino acid loss impact nutrition provision, with 14.6% of the prescribed protein removed. Current recommendations for protein provision for children requiring CVVHDF should be adjusted to compensate for circuit-related loss. A higher resolution version of the Graphical abstract is available as Supplementary information.

Development of consensus recommendations for the management of post-operative chylothorax in paediatric CHD.

OBJECTIVE: A standardised multi-site approach to manage paediatric post-operative chylothorax does not exist and leads to unnecessary practice variation. The Chylothorax Work Group utilised the Pediatric Critical Care Consortium infrastructure to address this gap. METHODS: Over 60 multi-disciplinary providers representing 22 centres convened virtually as a quality initiative to develop an algorithm to manage paediatric post-operative chylothorax. Agreement was objectively quantified for each recommendation in the algorithm by utilising an anonymous survey. "Consensus" was defined as ≥ 80% of responses as "agree" or "strongly agree" to a recommendation. In order to determine if the algorithm recommendations would be correctly interpreted in the clinical environment, we developed ex vivo simulations and surveyed patients who developed the algorithm and patients who did not. RESULTS: The algorithm is intended for all children (<18 years of age) within 30 days of cardiac surgery. It contains rationale for 11 central chylothorax management recommendations; diagnostic criteria and evaluation, trial of fat-modified diet, stratification by volume of daily output, timing of first-line medical therapy for "low" and "high" volume patients, and timing and duration of fat-modified diet. All recommendations achieved "consensus" (agreement >80%) by the workgroup (range 81-100%). Ex vivo simulations demonstrated good understanding by developers (range 94-100%) and non-developers (73%-100%). CONCLUSIONS: The quality improvement effort represents the first multi-site algorithm for the management of paediatric post-operative chylothorax. The algorithm includes transparent and objective measures of agreement and understanding. Agreement to the algorithm recommendations was >80%, and overall understanding was 94%.

Pericardial Effusions After the Arterial Switch Operation: A PHIS Database Review.

Background: Pericardial effusion (PCE) is a significant complication after pediatric cardiac surgery. This study investigates PCE development after the arterial switch operation (ASO) and its short-term and longitudinal impacts. Methods: A retrospective review of the Pediatric Health Information System database. Patients with dextro-transposition of the great arteries who underwent ASO from January 1, 2004, to March 31, 2022, were identified. Patients with and without PCE were analyzed with descriptive, univariate, and multivariable regression statistics. Results: There were 4896 patients identified with 300 (6.1%) diagnosed with PCE. Thirty-five (11.7%) with PCE underwent pericardiocentesis. There were no differences in background demographics or concomitant procedures between those who developed PCE and those who did not. Patients who developed PCE more frequently had acute renal failure (N = 56 (18.7%) vs N = 603(13.1%), P = .006), pleural effusions (N = 46 (15.3%) vs N = 441 (9.6%), P = .001), mechanical circulatory support (N = 26 (8.7%) vs N = 199 (4.3%), P < .001), and had longer postoperative length of stay (15 [11-24.5] vs 13 [IQR: 9-20] days). After adjustment for additional factors, pleural effusions (OR = 1.7 [95% CI: 1.2-2.4]), and mechanical circulatory support (OR = 1.81 [95% CI: 1.15-2.85]) conferred higher odds of PCE. There were 2298 total readmissions, of which 46 (2%) had PCE, with no difference in median readmission rate for patients diagnosed with PCE at index hospitalization (median 0 [IQR: 0-1] vs 0 [IQR: 0-0], P = .208). Conclusions: PCE occurred after 6.1% of ASO and was associated with pleural effusions and mechanical circulatory support. PCE is associated with morbidity and prolonged length of stay; however, there was no association with in-hospital mortality or readmissions.

Comparison of Local and Systemic Inflammation During Invasive Versus Noninvasive Ventilation in Rats.

The impact of noninvasive ventilation (NIV) on local and systemic inflammation is poorly characterized, particularly when compared with invasive mechanical ventilation (IMV). We sought to quantify the local and systemic inflammatory response of these 2 respiratory treatments in rats with lipopolysaccharide (LPS)-induced lung injury (LPS-injured) and healthy rats. Animals were subjected to 4 h of NIV or IMV treatments at noninjurious settings, or 4 h of control treatment in which healthy or LPS-injured animals remained spontaneously breathing under isoflurane anesthesia with no respiratory support. Cytokines were then quantified in the serum and lung tissue by multiplex enzyme-linked immunosorbent assay. Contrary to our hypothesis, there were no significant differences in cytokine levels in serum or lung when comparing the NIV- and IMV-treated groups; this was true in both LPS-injured and healthy rats. However, within the LPS-injured group, pulmonary levels of interleukin (IL)-1α, IL-6, and tumor necrosis factor α were significantly lower in the NIV-treated group than in control but not in the IMV-treated group compared with control. We conclude that NIV, unlike IMV, could attenuate local inflammation.

Pediatric Surgical Pulmonary Valve Replacement Outcomes After Implementation of a Clinical Pathway.

BACKGROUND: Standardization of perioperative care can reduce resource utilization while improving patient outcomes. We sought to describe our outcomes after the implementation of a perioperative clinical pathway for pediatric patients undergoing elective surgical pulmonary valve replacement and compare these results to previously published national benchmarks. METHODS: A retrospective single-center descriptive study was conducted of all pediatric patients who underwent surgical pulmonary valve replacement from 2017 through 2020, after the implementation of a clinical pathway. Outcomes included hospital length of stay and 30-day reintervention, readmission, and mortality. RESULTS: Thirty-three patients (55% female, median age 11 [7, 13] years, 32 [23, 44] kg) were included in the study. Most common diagnosis and indication for surgery was Tetralogy of Fallot (61%) with pulmonary valve insufficiency (88%). All patients had prior cardiac surgery. Median hospital length of stay was 2 [2, 2] days, and longest length of stay was three days. There were no 30-day readmissions, reinterventions, or mortalities. Median follow-up time was 19 [9, 31] months. CONCLUSIONS: Formalization of a perioperative surgical pulmonary valve replacement clinical pathway can safely promote short hospital length of stay without any short-term readmissions or reinterventions, especially when compared with previously published benchmarks. Such formalization enables the dissemination of best practices to other institutions to reduce hospital length of stay and limit costs.

Novel Multidisciplinary Management of Acute Kidney Injury After Infant Orthotopic Heart Transplantation.

Acute kidney injury following orthotopic heart transplantation in pediatric recipients is often multifactorial, requiring balance of immune suppression, nephrotoxic medication exposure, nutrition, and fluid status. Therapeutic options are often limited by patient size and hemodynamic stability. We describe a four-month, 4.9-kg female bridged by mechanical circulatory support to transplant after failed stage 1 palliation secondary to recurrent aortic stenosis and severe ventricular dysfunction. Posttransplant, kidney injury was managed by transcatheter relief of central obstruction from an anastomotic stricture and continuous renal replacement therapy, allowing uninterrupted immune suppression, medication, and nutrition delivery until sufficient recovery of renal function.