Proposed entry criteria for postoperative cardiac extracorporeal membrane oxygenation after pediatric open heart surgery

Association between Serum Lactate and Morbidity and Mortality in Neonates: A Systematic Review and Meta-Analysis

OBJECTIVE

Lactate is a marker of hypoperfusion in critically ill patients. Whether lactate is useful for identifying and stratifying neonates with a higher risk of adverse outcomes remains unknown. This study aimed to investigate the association between lactate and morbidity and mortality in neonates.

METHODS

A meta-analysis was performed to determine the association between blood lactate levels and outcomes in neonates. Ovid MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov were searched from inception to 1 May 2021. A total of 49 observational studies and 14 data accuracy test studies were included. The risk of bias was assessed using the Newcastle-Ottawa Scale for observational studies and the QUADAS-2 tool for data accuracy test studies. The primary outcome was mortality, while the secondary outcomes included acute kidney injury, necessity for renal replacement therapy, neurological outcomes, respiratory morbidities, hemodynamic instability, and retinopathy of prematurity.

RESULTS

Of the 3184 articles screened, 63 studies fulfilled all eligibility criteria, comprising 46,069 neonates. Higher lactate levels are associated with mortality (standard mean difference, -1.09 [95% CI, -1.46 to -0.73]). Using the estimated sensitivity (0.769) and specificity (0.791) and assuming a prevalence of 15% for adverse outcomes (median of prevalence among studies) in a hypothetical cohort of 10,000 neonates, assessing the lactate level alone would miss 346 (3.46%) cases (false negative) and wrongly diagnose 1776 (17.76%) cases (false positive).

CONCLUSIONS

Higher lactate levels are associated with a greater risk of mortality and morbidities in neonates. However, our results do not support the use of lactate as a screening test to identify adverse outcomes in newborns. Research efforts should focus on analyzing serial lactate measurements, rather than a single measurement.

Experts' recommendations for the management of cardiogenic shock in children

Cardiogenic shock which corresponds to an acute state of circulatory failure due to impairment of myocardial contractility is a very rare disease in children, even more than in adults. To date, no international recommendations regarding its management in critically ill children are available. An experts’ recommendations in adult population have recently been made (Levy et al. Ann Intensive Care 5(1):52, 2015; Levy et al. Ann Intensive Care 5(1):26, 2015). We present herein recommendations for the management of cardiogenic shock in children, developed with the grading of recommendations’ assessment, development, and evaluation system by an expert group of the Groupe Francophone de Réanimation et Urgences Pédiatriques (French Group for Pediatric Intensive Care and Emergencies). The recommendations cover four major fields of application such as: recognition of early signs of shock and the patient pathway, management principles and therapeutic goals, monitoring hemodynamic and biological variables, and circulatory support (indications, techniques, organization, and transfer criteria). Major principle care for children with cardiogenic shock is primarily based on clinical and echocardiographic assessment. There are few drugs reported as effective in childhood in the medical literature. The use of circulatory support should be facilitated in terms of organization and reflected in the centers that support these children. Children with cardiogenic shock are vulnerable and should be followed regularly by intensivist cardiologists and pediatricians. The experts emphasize the multidisciplinary nature of management of children with cardiogenic shock and the importance of effective communication between emergency medical assistance teams (SAMU), mobile pediatric emergency units (SMUR), pediatric emergency departments, pediatric cardiology and cardiac surgery departments, and pediatric intensive care units.

Predicting major adverse events after cardiac surgery in children

OBJECTIVES

To develop a reliable predictor of major adverse events after pediatric cardiac surgery, with the aim of reducing mortality of cardiac extracorporeal life support through earlier, more accurate patient selection.

DESIGN

Prospective observational study.

SETTING

Tertiary level pediatric intensive care unit.

PATIENTS

Fifty-two children undergoing open heart surgery considered above-average risk based on preoperative assessment.

INTERVENTIONS

None; strictly observational study.

MEASUREMENTS AND MAIN RESULTS

A wide range of measurements was made at 3, 6, 9, 12, and 24 hrs after surgery, including: oxygen consumption, central venous pressure and oxygen saturation (Scvo2), cardiac output (Fick), heart rate, arterial pressure, arterial lactate, urine output, core-toe temperature gradient, and derived hemodynamic variables. Six children had major adverse events; three needed extracorporeal life support, two died. There were no correlations between routine postoperative measurements (blood pressure, pulse, temperature gradient, central venous pressure) and any measure of cardiac function, and neither group of variables predicted adverse outcomes. Lactate (>8 mmol/L) and Scvo2 (<40%) had high sensitivity (both 73.7%) and specificity (96.3% and 95.4%, respectively), for predicting major adverse event but positive predictive values for both were low (63.6% and 58.3%, respectively). The ratio of the two had better predictive power than the individual values. When the ratio (Scvo2, %)/(lactate, mmol/L) fell below 5, the positive predictive value for major adverse event was 93.8% (sensitivity 78.9%, specificity 90.5%). The effect was present at all postoperative time points.

CONCLUSIONS

Lactate and Scvo2 are the only postoperative measurements with predictive power for major adverse events. Forming a ratio of the two (Scvo2/lactate), seems to improve predictive power, presumably by combining their individual predictive strengths. Both measures have excellent specificities but lower sensitivities. Predictive power of single measures is only fair but can be improved, in high risk patients, by monitoring repeated measures over time.

Continuous monitoring of central venous oxygen saturation (Pediasat) in pediatric patients undergoing cardiac surgery: a validation study of a new technology

OBJECTIVE

Mixed venous oxygen saturation and central venous oxygen saturation are considered possible indicators of the adequacy of oxygen delivery with respect to the oxygen needs of critically ill adult and pediatric patients. The present study was aimed at validating the accuracy of a new technology (Pediasat central venous catheter) in providing a continuous measurement of the central venous oxygen saturation in pediatric patients.

DESIGN

A prospective observational study.

PARTICIPANTS

Thirty pediatric patients (age, 6 days-9 years) undergoing cardiac operations. Data obtained with the Pediasat during and after the operation were compared with simultaneously collected venous blood samples analyzed with standard laboratory techniques.

SETTING

A clinical research hospital.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A Bland and Altman analysis was performed on 30 matched sets of data collected before cardiopulmonary bypass, during cardiopulmonary bypass, and during the intensive care unit stay. Before cardiopulmonary bypass, there was a bias of 0.003, with lower and upper limits of agreement, -5.84 and 5.84 (percentage error, 17.3%). During cardiopulmonary bypass, the bias was 0.57 and lower and upper limits of agreement were -7.7 and 8.7 (percentage error, 23.2%). At 2 hours after the arrival in the intensive care unit, the bias was -0.6 and the lower and upper limits of agreement were -8 and 6.8 (percentage error, 20.3%).

CONCLUSIONS

Because of the minimal bias and the acceptable value of percentage error, the Pediasat may be considered as an accurate tool for the continuous measurement of the central venous oxygen saturation in neonates and pediatric patients during and after cardiac operations.

Recent developments in the perioperative management of the paediatric cardiac patient

PURPOSE OF REVIEW

Survival of infants born with complex cardiac anomalies has dramatically improved, and the growing population of patients with congenital heart disease reaching adulthood has resulted in an increased incidence of long-term complications related to the perioperative period. This review focuses on recent advances in strategies to prevent, detect, treat, or predict early and late complications arising from open heart surgery for congenital heart disease.

RECENT FINDINGS

Aprotinine and recombinant factor VIIa may effectively reduce the risk of excessive perioperative bleeding, and the use of steroids, complement component C4A, heparin-coated circuits, and modified ultrafiltration may play a role in the control of the postoperative inflammatory response. Milrinone is becoming increasingly popular in the prevention and treatment of the reduced postoperative cardiac output, and extracorporeal life support has become a well established and successful form of support for postoperative myocardial dysfunction, even in the functionally univentricular heart. In recent years interest increased in optimizing myocardial protection using contents-differentiated and temperature-differentiated blood cardioplegia and in optimizing cerebral protection using a higher haematocrit during bypass and by using selective regional perfusion in favour of circulatory arrest.

SUMMARY

Hearts can be mended, but salvation of hearts and brains needs further rigorous attention.

Cost-utility analysis of salvage cardiac extracorporeal membrane oxygenation in children

BACKGROUND

Indications for extracorporeal membrane oxygenation therapy have expanded to include cardiopulmonary arrest and support after congenital heart surgery. Data from a national registry have reported that cardiac patients have the poorest survival of all extracorporeal membrane oxygenation recipients. Concerns have been raised about the appropriateness of such an aggressive strategy, especially in light of the high costs and potential for long-term neurologic disability. We reviewed our experience with salvage cardiac extracorporeal membrane oxygenation to determine the cost-utility, which accounts for both costs and quality of life.

METHODS

Medical records of patients with congenital heart disease receiving salvage cardiac extracorporeal membrane oxygenation between January 2000 and May 2004 were reviewed. Charges for all medical care after the institution of extracorporeal membrane oxygenation were determined and converted to costs by published standards. The quality-of-life status of survivors was determined with the Health Utilities Index Mark II.

RESULTS

Salvage cardiac extracorporeal membrane oxygenation was instituted in 32 patients (18 for cardiopulmonary arrest and 14 for cardiac failure after heart surgery) at a median age of 2.0 months (range, 4 days to 5.1 years). Congenital heart disease was present in 27 (84%). The mean duration of extracorporeal membrane oxygenation support was 5.1 +/- 4.1 days. Survival to hospital discharge was 50%, including 1 patient bridged to heart transplantation. Survival to 1 year was 47%. The mean score of the Health Utilities Index for the survivors was 0.75 +/- 0.19 (range, 0.41-1.0). The median cost for hospital stay after the institution of extracorporeal membrane oxygenation was USD 156,324 per patient. The calculated cost-utility for salvage extracorporeal membrane oxygenation in this population was USD 24,386 per quality-adjusted life-year saved, which would be considered within the range of accepted cost-efficacy (< USD 50,000 per quality-adjusted life-year saved).

CONCLUSIONS

Salvage cardiac extracorporeal membrane oxygenation results in reasonable survival and is justified on a cost-utility basis.

Transcatheter techniques in the management of perioperative vascular obstruction

The role of transcatheter intervention for the treatment of vascular obstruction is well documented in the preoperative or remote postoperative settings. More recently, the roles of angioplasty and stent implantation have been advocated as intraoperative and immediate postoperative strategies. As one considers the inherent advantages in this cooperative approach to congenital heart disease, the development of a truly hybrid interventional suite seems imperative.

Predictors of mortality at initiation of peritoneal dialysis in children after cardiac surgery

BACKGROUND

The development of renal dysfunction in the postoperative course of cardiac surgery is still associated with high mortality in pediatric patients. In particular for small infants peritoneal dialysis offers a secure and useful treatment option. The aim of the present study was to investigate if routinely used laboratory and clinical variables could help predict mortality at initiation of peritoneal dialysis.

METHODS

We performed a retrospective chart analysis of pediatric intensive care unit patients with renal dysfunction who were treated with peritoneal dialysis after cardiac surgery between 1993 and 2001 and analyzed variables obtained 3 hours or less before starting peritoneal dialysis.

RESULTS

Results are documented as means and standard errors. A total of 1141 children underwent a cardiac operation on cardiopulmonary bypass. Sixty-two children (5.4%) were treated with peritoneal dialysis. Mortality was 40.3% (37 survivors, 25 nonsurvivors). The pH in survivors was 7.35 (0.01); in nonsurvivors it was 7.23 (0.03; p = 0.0037). Base excess in survivors was -1.37 mmol/L (0.61); in nonsurvivors it was -7.17 mmol/L (1.49; p = 0.0026). Lactate in survivors was 4.5 mmol/L (0.60); in nonsurvivors it was 10.5 mmol/L (1.78; p = 0.0089). Positive inspiratory pressure in survivors was 24.6 cm H(2)O (0.78); in nonsurvivors it was 28.9 cm H(2)O (1.08; p = 0.0274). Tidal volume per kilogram bodyweight in survivors was 11.0 mL/kg (0.48); in nonsurvivors it was 8.7 mL/kg (0.50; p = 0.0493).

CONCLUSIONS

We conclude from our data that the consideration of pH, base excess, lactate, positive inspiratory pressure, and tidal volume per kilogram bodyweight help predict mortality at initiation of peritoneal dialysis. We were able to observe significant differences between survivors and nonsurvivors using these variables.

Neonatal and pediatric extracorporeal membrane oxygenation using nonocclusive blood pumps: the Vienna experience

Neonatal and pediatric extracorporeal membrane oxygenation (ECMO) is carried out commonly using occlusive blood pumps. Centrifugal pumps provide simple and safe technology for transportation on ECMO. The assistence respiratoire extra corporelle (AREC) system enables single needle venovenous ECMO for infants. We report on our experience with neonatal and pediatric ECMO treatments using nonocclusive blood pumps. One-hundred forty-six ECMO treatments were performed for cardiac, neonatal, and pediatric indications in 54, 19, and 27% of cases. Centrifugal pumps were used in 99, and the AREC system in 42 cases. Hospital mortality was estimated retrospectively and influence of type of pump, type of ECMO belonging to indication group, and lactate at ECMO installation were estimated. Irreversible organ failure leading to ECMO termination was investigated within groups of indications. Survival (recent 50 ECMO treatments) was 80, 70, 43, and 30% after meconium aspiration syndrome, acute respiratory distress syndrome, cardiac surgery, and prolonged resuscitation. Lactate exceeding 100 mg/dl at ECMO installation predicted significantly worse outcome. Cerebral damage was the main reason for ECMO termination in all but persistent circulatory failure in the cardiac group. Myocardial recovery resulted in all except 2 cardiac cases. Nonocclusive blood pumps can be used safely in neonatal and pediatric ECMO. Early installation may improve outcome markedly. In cardiac cases results of surgery should be thoroughly investigated on the table before ECMO installation to prevent hopeless ECMO treatments.