A Review of Goal-Directed Cardiopulmonary Bypass Management in Pediatric Cardiac Surgery

Carbon dioxide production index (VCO2i) predicts hyperlactatemia during cardiopulmonary bypass in ediatric carDiac surGery (pGDP- VCO2i): Study protocol for a nested case-control trial

BACKGROUND

Hyperlactatemia (HL) during cardiopulmonary bypass (CPB) is relatively frequent in infants and associates with increased morbidity and mortality. Studies on adults have shown that carbon dioxide production index (VCO2i) during CPB is linked to the occurrence of HL, with 'critical thresholds' for VCO2i reported to be 60 mL/min/m2. However, considering infants have a higher metabolic rate and lower tolerance to hypoxia, the critical threshold of VCO2i in infants cannot be replied to the existing adults' standards. The objective of this study is to investigate the association of VCO2i during CPB and HL, and explore the critical VCO2i threshold during CPB in infants.

METHODS

VCO2i predicts hyperlactatemia during cardiopulmonary bypass in pediatric cardiac surgery (pGDP-VCO2i) is a nested case-control study. A cohort of consecutive pediatric patients of less than 3 years of age, undergoing congenital cardiac surgeries between May 2021 and December 2023 in West China Hospital will be enrolled. The VCO2i levels of each patient will be recorded every 5 min during CPB. The primary outcome is the rate of HL. The infants will be divided into two groups based on the presence or not of HL. Pre- and intraoperative factors will be tested for independent association with HL. Then, we will make an analysis, and the critical value of VCO2i will be obtained. The postoperative outcome of patients with or without HL will be compared.

DISCUSSION

This will be the first trial to investigate the association of VCO2i during CPB and HL, and explore the critical VCO2i threshold during CPB in pediatrics. The results of this study are expected to lay a foundation for clinical application of goal-directed perfusion (GDP) management strategy, and optimize the perfusion strategy and improve the prognosis of pediatric patients undergoing cardiac surgery.

TRIAL REGISTRATION

Chictr.org.cn, ChiCTR2100044296 on 16 March 2021.

Risk factors of gastrointestinal bleeding after cardiopulmonary bypass in children: a retrospective study

Background

During cardiac surgery that involved cardiopulmonary bypass (CPB) procedure, gastrointestinal (GI) system was known to be vulnerable to complications such as GI bleeding. Our study aimed to determine the incidence and risk factors associated with GI bleeding in children who received CPB as part of cardiac surgery.

Methods

This retrospective study enrolled patients aged <18 years who underwent cardiac surgery with CPB from 2013 to 2019 at Shanghai Children's Medical Center. The primary outcome was the incidence of postoperative GI bleeding in children, and the associated risk factors with postoperative GI bleeding episodes were evaluated.

Results

A total of 21,893 children who underwent cardiac surgery with CPB from 2013 to 2019 were included in this study. For age distribution, 636 (2.9%) were neonates, 10,984 (50.2%) were infants, and 10,273 (46.9%) were children. Among the 410 (1.9%) patients with GI bleeding, 345 (84.2%) survived to hospital discharge. Incidence of GI bleeding in neonates, infants and children were 22.6% (144/636), 2.0% (217/10,984) and 0.5% (49/10,273), respectively. The neonates (22.6%) group was associated with highest risk of GI bleeding. Patients with GI bleeding showed longer length of hospital stays (25.8 ± 15.9 vs. 12.5 ± 8.9, P < 0.001) and higher mortality (15.9% vs. 1.8%, P < 0.001). Multivariate logistic regression analysis showed that age, weight, complicated surgery, operation time, use of extracorporeal membrane oxygenation (ECMO), low cardiac output syndrome (LCOS), hepatic injury, artery lactate level, and postoperative platelet counts were significantly associated with increased risk of GI bleeding in children with congenital heart disease (CHD) pediatric patients that underwent CPB procedure during cardiac surgery.

Conclusion

The study results suggest that young age, low weight, long operation time, complicated surgery, use of ECMO, LCOS, hepatic injury, high arterial lactate level, and low postoperative platelet counts are independently associated with GI bleeding after CPB in children.

Advanced Neuromonitoring Modalities on the Horizon: Detection and Management of Acute Brain Injury in Children

Timely detection and monitoring of acute brain injury in children is essential to mitigate causes of injury and prevent secondary insults. Increasing survival in critically ill children has emphasized the importance of neuroprotective management strategies for long-term quality of life. In emergent and critical care settings, traditional neuroimaging modalities, such as computed tomography and magnetic resonance imaging (MRI), remain frontline diagnostic techniques to detect acute brain injury. Although detection of structural and anatomical abnormalities remains crucial, advanced MRI sequences assessing functional alterations in cerebral physiology provide unique diagnostic utility. Head ultrasound has emerged as a portable neuroimaging modality for point-of-care diagnosis via assessments of anatomical and perfusion abnormalities. Application of electroencephalography and near-infrared spectroscopy provides the opportunity for real-time detection and goal-directed management of neurological abnormalities at the bedside. In this review, we describe recent technological advancements in these neurodiagnostic modalities and elaborate on their current and potential utility in the detection and management of acute brain injury.

Transparency, Public Reporting and a Culture of Change to Quality and Safety in Cardiac Surgery

Academic medical centers have a duty to serve as hospitals of last resort for advanced cardiac surgical care and therefore manage patients at elevated risk of post-operative morbidity and mortality. They must also meet state and professional quality targets devised to protect the public. The tension between these imperatives can be managed by a multi-dimensional quality improvement program which aims to manage risk, optimize outcomes and exclude futile operations. We here share our approach to this process, its impact on our institution and discuss pertinent issues relevant to institutions in a similar situation.

Adverse fibrosis remodeling and aortopulmonary collateral flow are associated with poor Fontan outcomes

BACKGROUND

The extent and significance in of cardiac remodeling in Fontan patients are unclear and were the subject of this study.

METHODS

This retrospective cohort study compared cardiovascular magnetic resonance (CMR) imaging markers of cardiac function, myocardial fibrosis, and hemodynamics in young Fontan patients to controls.

RESULTS

Fifty-five Fontan patients and 44 healthy controls were included (median age 14 years (range 7-17 years) vs 13 years (range 4-14 years), p = 0.057). Fontan patients had a higher indexed end-diastolic ventricular volume (EDVI 129 ml/m2 vs 93 ml/m2, p < 0.001), and lower ejection fraction (EF 45% vs 58%, p < 0.001), circumferential (CS - 23.5% vs - 30.8%, p < 0.001), radial (6.4% vs 8.2%, p < 0.001), and longitudinal strain (- 13.3% vs - 24.8%, p < 0.001). Compared to healthy controls, Fontan patients had higher extracellular volume fraction (ECV) (26.3% vs 20.6%, p < 0.001) and native T1 (1041 ms vs 986 ms, p < 0.001). Patients with a dominant right ventricle demonstrated larger ventricles (EDVI 146 ml/m2 vs 120 ml/m2, p = 0.03), lower EF (41% vs 47%, p = 0.008), worse CS (- 20.1% vs - 25.6%, p = 0.003), and a trend towards higher ECV (28.3% versus 24.1%, p = 0.09). Worse EF and CS correlated with longer cumulative bypass (R = - 0.36, p = 0.003 and R = 0.46, p < 0.001), cross-clamp (R = - 0.41, p = 0.001 and R = 0.40, p = 0.003) and circulatory arrest times (R = - 0.42, p < 0.001 and R = 0.27, p = 0.03). T1 correlated with aortopulmonary collateral (APC) flow (R = 0.36, p = 0.009) which, in the linear regression model, was independent of ventricular morphology (p = 0.9) and EDVI (p = 0.2). The composite outcome (cardiac readmission, cardiac reintervention, Fontan failure or any clinically significant arrhythmia) was associated with increased native T1 (1063 ms vs 1026 ms, p = 0.029) and EDVI (146 ml/m2 vs 118 ml/m2, p = 0.013), as well as decreased EF (42% vs 46%, p = 0.045) and worse CS (- 22% vs - 25%, p = 0.029). APC flow (HR 5.5 CI 1.9-16.2, p = 0.002) was independently associated with the composite outcome, independent of ventricular morphology (HR 0.71 CI 0.30-1.69 p = 0.44) and T1 (HR1.006 CI 1.0-1.13, p = 0.07).

CONCLUSIONS

Pediatric Fontan patients have ventricular dysfunction, altered myocardial mechanics and increased fibrotic remodeling. Cumulative exposure to cardiopulmonary bypass and increased aortopulmonary collateral flow are associated with myocardial dysfunction and fibrosis. Cardiac dysfunction, fibrosis, and collateral flow are associated with adverse outcomes.

Red blood cell storage duration and peri-operative outcomes in paediatric cardiac surgery

BACKGROUND

Prior research on red blood cell (RBC) storage duration and clinical outcomes in paediatric cardiac surgery has shown conflicting results. The purpose of this study was to evaluate whether blood stored for a longer duration is harmful in these patients.

METHODS

We performed a retrospective cohort study of paediatric patients undergoing cardiac surgery at our institution between January 2011 and June 2015. Patients were stratified based on whether they were transfused RBCs stored for ≤15 days (fresher blood) or >15 days (older blood). The primary outcome was composite morbidity, with prolonged length of stay (LOS) as a secondary outcome. Subgroup analyses were performed after stratification by RBC transfusion volume (≤2 vs. >2 RBC units). Multivariable logistic regression models were used to assess the impact of RBC storage duration on composite morbidity and prolonged LOS.

RESULTS

Of 461 patients, 122 (26·5%) received fresher blood and 339 (73·5%) received older blood. The overall rate of composite morbidity was 18·0% (n = 22) for patients receiving fresher blood and 13·6% (n = 46) for patients receiving older blood (P = 0·24). In the risk-adjusted model, patients receiving older blood did not exhibit an increased risk of composite morbidity (OR: 0·74, 95% CI: 0·37-1·47, P = 0·40) or prolonged LOS (OR: 0·72, 95% CI: 0·38-1·35, P = 0·30) compared to patients receiving fresher blood. Similar results were seen after stratification by RBC transfusion volume.

CONCLUSIONS

Transfusing RBCs stored for a longer duration was not associated with an increased risk of morbidity or prolonged LOS in paediatric cardiac surgery patients.

Is thoracoscopic esophageal atresia repair safe in the presence of cardiac anomalies?

BACKGROUND

Esophageal atresia (EA) is often associated with congenital heart disease (CHD). Repair of EA by the thoracoscopic approach places physiological stress on a newborn with CHD. This paper reviews the outcomes of infants with CHD who had undergone thoracoscopic EA repair, comparing their outcomes to those without CHD.

METHODS

This was a review of infants who underwent thoracoscopic EA repair from 2009 to 2017 at one institution. Operative time and outcomes were analyzed in relation to CHD status.

RESULTS

Twenty five infants underwent thoracoscopic EA repair during the study period. Seventeen (68%) had associated anomalies of whom 9 (36%) had cardiac anomalies. The mean operative time was 217 min. There was no difference in operative time between CHD and non-CHD cases (estimate 20 min longer operative time in the presence of a cardiac anomaly [95% CI -20 to 57]). Two cases were converted to open thoracotomy; both were non-CHD. There was no difference in the time to feeding, time in intensive care unit or time in hospital between CHD and non-CHD cases. Five patients developed an anastomotic leak (two CHD and three non-CHD) of which two were clinical; all were managed conservatively. There was no case of recurrent fistula.

CONCLUSIONS

This pilot study did not find evidence that thoracoscopic EA repair compromised outcomes in children with congenital heart disease. A prospective multicenter study with long-term follow-up is recommended to confirm whether thoracoscopic repair in CHD is truly equivalent to the open operation.

TYPE OF STUDY

Therapeutic.

LEVEL OF EVIDENCE

Level III.

Trends and Updates on Cardiopulmonary Bypass Setup in Pediatric Cardiac Surgery

Perfusion strategies for cardiopulmonary bypass have direct consequences on pediatric cardiac surgery outcomes. However, inconsistent study results and a lack of uniform evidence-based guidelines for pediatric cardiopulmonary bypass management have led to considerable variability in perfusion practices among, and even within, institutions. Important aspects of cardiopulmonary bypass that can be optimized to improve clinical outcomes of pediatric patients undergoing cardiac surgery include extracorporeal circuit components, priming solutions, and additives. This review summarizes the current literature on circuit components and priming solution composition with an emphasis on crystalloid, colloid, and blood-based primes, as well as mannitol, bicarbonate, and calcium.