Short-term outcomes in premature neonates adhering to the philosophy of supportive care allowing for weight gain and organ maturation prior to cardiac surgery

Outcomes after neonatal cardiac surgery: The impact of a dedicated neonatal cardiac program

OBJECTIVES

Prematurity is a risk factor for in-hospital mortality after cardiac surgery. The structure of intensive care unit models designed to deliver optimal care to neonates including those born preterm with critical congenital heart disease is unknown. The objective of this study was to evaluate in-hospital outcomes after cardiac surgery across gestational ages in an institution with a dedicated neonatal cardiac program.

METHODS

This study is a single-center, retrospective review of infants who underwent cardiac surgical interventions from our dedicated neonatal cardiac intensive care program between 2006 and 2017. We evaluated in-hospital mortality and morbidity rates across all gestational ages.

RESULTS

A total of 1238 subjects met inclusion criteria over a 11-year period. Overall in-hospital mortality after cardiac surgery was 6.1%. The mortality rate in very preterm infants (n = 68; <34 weeks' gestation at birth) was 17.6% (odds ratio, 3.52 [1.4-8.53]), versus 4.3% in full-term (n = 563; 39-40 weeks) referent/control infants. Very preterm infants with isolated congenital heart disease (without evidence of other affected organ systems) experienced a mortality rate of 10.5% after cardiac surgery. Neither the late preterm (34-36 ^6/7 weeks) nor the early term (37-38 ^6/7) groups had significantly increased odds of mortality compared with full-term infants. Seventy-eight percent of very preterm infants incurred a preoperative or postoperative complication (odds ratio, 4.78 [2.61-8.97]) compared with 35% of full-term infants.

CONCLUSIONS

In this study of a single center with a dedicated neonatal cardiac program, we report some of the lowest mortality and morbidity rates after cardiac surgery in preterm infants in the recent era. The potential survival advantage of this model is most striking for very preterm infants born with isolated congenital heart disease.

Necrotizing enterocolitis in patients with congenital heart disease: A single center experience

PURPOSE

The purpose of this study was to evaluate the characteristics of patients with congenital heart disease (CHD) who developed necrotizing enterocolitis (NEC).

METHODS

A retrospective review of neonates with CHD at a tertiary care center between January 2006 and January 2016 was performed. Diagnosis of NEC was based on modified Bell's criteria. Patients were grouped by Risk Adjustment for Congenital Heart Surgery (RACHS-1) or by ductal-dependent (DD) lesions that require a patent ductus arteriosus to supply pulmonary or systemic circulation.

RESULTS

Of 1811 neonates with CHD, 3.4% (n=61) developed NEC. Eighteen (30%) of these required surgical management. The rate of NEC among DD patients was 5% (n=33/653), compared to 2.4% (n=28/1158) in the non-DD group (p=0.003). RACHS-1 score>2 had a higher rate of NEC 6.2% (41/658) compared to RACHS-1≤2 cases, 1.7% (20/1153) (p=0.005). DD patients and complex patients with RACHS-1>2 were more likely to develop NEC after cardiac surgery. Hypoplastic left heart syndrome patients had a rate of 9% (n=16/185). Surgical NEC was more prevalent in the non-DD group. Mortality was similar among groups.

CONCLUSION

CHD patients with ductal-dependent lesions or complex cases (RACHS-1 score>2) have higher rates of NEC than non-ductal-dependent patients or RACHS-1 score of 2 or less. Mortality is similar regardless of ductal dependence, but surgical NEC was more prevalent in non-DD patients.

LEVEL OF EVIDENCE

Level IIb.

Structural equation modelling exploration of the key pathophysiological processes involved in cardiac surgery-related acute kidney injury in infants

Background

Uncertainties about the pathophysiological processes resulting in cardiac surgery-related acute kidney injury (AKI) in infants concern the relative impact of the most prominent risk factors, the clinical relevance of changes in glomerular filtration rate vs tubular injury, and the usefulness of available diagnostic tools. Structural equation modelling could allow for the assessment of these complex relationships.

Methods

A structural model was specified using data from a prospective observational cohort of 200 patients <1 year of age undergoing cardiopulmonary bypass surgery. It included four latent variables: AKI, modelled as a construct of perioperative creatinine variation, of oliguria and of urine neutrophil gelatinase-associated lipocalin (uNGAL) concentrations; the cardiopulmonary bypass characteristics; the occurrence of a post-operative low cardiac output syndrome and the post-operative outcome.

Results

The model showed a good fit, and all path coefficients were statistically significant. The bypass was the most prominent risk factor, with a path coefficient of 0.820 (95 % CI 0.527–0.979), translating to a 67.2 % explanation for the risk of AKI. A strong relationships was found between AKI and early uNGAL excretion, and between AKI and the post-operative outcome, with path coefficients of 0.611 (95 % CI 0.347–0.777) and 0.741 (95 % CI 0.610–0.988), respectively. The path coefficient between AKI and a >50 % increase in serum creatinine was smaller, with a path coefficient of 0.443 (95 % CI 0.273–0.596), and was intermediate for oliguria, defined as urine output <0.5 ml kg⁻¹ h⁻¹, with a path coefficient of 0.495 (95 % CI 0.250–0.864). A path coefficient of −0.229 (95 % CI −0.319 to 0.060) suggested that the risk of AKI during the first year of life did not increase with younger age at surgery.

Conclusions

These findings suggest that cardiac surgery-related AKI in infants is a translation of tubular injury, predominately driven by the cardiopulmonary bypass, and linked to early uNGAL excretion and to post-operative outcome.

Trial registration

ClinicalTrials.gov identifier NCT01219998. Registered 11 October 2010.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1350-1) contains supplementary material, which is available to authorized users.

Perinatal Decision Making for Preterm Infants with Congenital Heart Disease: Determinable Risk Factors for Mortality

For premature infants with congenital heart disease (CHD), it may be unclear when the burdens of treatment outweigh potential benefits. Parents may thus have to choose between comfort care at birth and medical stabilization until surgical repair is feasible. Better defined outcome data, including risk factors for mortality, are needed to counsel expectant parents who are considering intensive care for premature infants with CHD. We sought to evaluate outcomes in this population to inform expectant parents considering intensive versus palliative care at birth. We performed a retrospective cohort study of infants born <34 weeks who received intensive care with critical or moderately severe CHD predicted to require surgery in the neonatal period or the first 6 months of life. 46 % of 54 infants survived. Among non-survivors, 74 % died prior to surgery (median age 24 days). Of the infants that underwent surgery, 75 % survived. Survival was lower among infants <32 weeks gestational age (GA) (p = 0.013), with birth weight (BW) <1500 g (p = 0.011), or with extra-cardiac anomalies (ECA) (p = 0.015). GA and ECA remained significant risk factors for mortality in multiple logistic regression analysis. In summary, GA < 32 weeks, BW < 1500 g, and ECA are determinable prenatally and were significant risk factors for mortality. The majority of infants who survived to cardiac intervention survived neonatal hospitalization, whereas most of the infants who died did so prior to surgery. For some expectant parents, this early declaration of mortality may support a trial of intensive care while avoiding burdensome interventions.

Management of the Preterm Infant with Congenital Heart Disease

The premature neonate with congenital heart disease (CHD) represents a challenging population for clinicians and researchers. The interaction between prematurity and CHD is poorly understood; epidemiologic study suggests that premature newborns are more likely to have CHD and that fetuses with CHD are more likely to be born premature. Understanding the key physiologic features of this special patient population is paramount. Clinicians have debated optimal timing for referral for cardiac surgery, and management in the postoperative period has rapidly advanced. This article summarizes the key concepts and literature in the care of the premature neonate with CHD.

Successful Surgical Management of Airway Perforation in Preterm Infants

Traumatic airway perforation during endotracheal intubation is an uncommon but life-threatening complication in preterm infants. Death usually occurs at the time of the injury, but in rare cases where the infant survives the initial resuscitation, therapeutic options include conservative versus surgical management. We describe three cases of airway perforation treated successfully with surgical intervention and without lung resection, utilizing novel graft material and cardiopulmonary bypass to facilitate repair. In preterm infants who survive the initial injury we advocate for early identification and surgical management with cardiopulmonary bypass when feasible.