Children undergoing heart transplant are at increased risk for postoperative vasodilatory shock

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.

Copeptin Release in Arterial Hypotension and Its Association with Severity of Disease in Critically Ill Children

Low copeptin levels may indicate inadequate arginine-vasopressin release promoting arterial hypotension, whereas high copeptin concentrations may reflect disease severity. This single-center prospective non-randomized clinical trial analyzed the course of blood copeptin in critically ill normo- and hypotensive children and its association with disease severity. In 164 patients (median age 0.5 years (interquartile range 0.1, 2.9)), the mean copeptin concentration at baseline was 43.5 pmol/L. Though not significantly different after 61 h (primary outcome, mean individual change: −12%, p = 0.36, paired t-test), we detected 1.47-fold higher copeptin concentrations during arterial hypotension when compared to normotension (mixed-effect ANOVA, p = 0.01). In total, 8 out of 34 patients (23.5%) with low copeptin concentrations <10 pmol/L were hypotensive. Copeptin was highest in the adjusted mixed-effect regression analysis within the first day (+20% at 14 h) and decreased significantly at 108 h (−27%) compared to baseline (p = 0.002). Moreover, we found a significant association with vasopressor-inotrope treatment intensity, infancy (1−12 months) and cardiopulmonary bypass (all p ≤ 0.001). In conclusion, high copeptin values were associated with arterial hypotension and severity of disease in critically ill children. This study does not support the hypothesis that low copeptin values might be indicative of arginine-vasopressin deficiency.

Cardiopulmonary Bypass-Induced Inflammatory Response: Pathophysiology and Treatment

OBJECTIVES

The objectives of this review are to discuss the pathophysiology of the pro-inflammatory response to the cardiopulmonary bypass circuit, the impact of ischemia reperfusion injury on post-operative organ function, the compensatory anti-inflammatory response and the evidence for immune-modulatory strategies and their impact on outcomes.

DATA SOURCE

MEDLINE, PubMed.

CONCLUSION

Innovations such as the development of more biocompatible surfaces and miniaturized circuits, as well as the increasing expertise of surgeons, anesthesiologists and perfusionists has transformed cardiac surgery and the use of cardiopulmonary bypass into a relatively routine procedure with favorable outcomes. Despite these refinements, the attendant inflammatory response to bypass, ischemia reperfusion injury and the compensatory anti-inflammatory response contribute to post-operative morbidity and mortality. Additional studies are needed to further delineate the impact of immunomodulatory strategies on outcomes.

Effect of corticosteroids on arginine vasopressin after pediatric cardiac surgery

INTRODUCTION

Arginine vasopressin's (AVP) efficacy in the treatment of refractory hypotension is, in part, dependent upon preinfusion endogenous AVP concentration. Corticosteroids, also commonly used to treat refractory hypotension, have been shown to suppress endogenous AVP release. We aimed to determine if corticosteroids affect endogenous AVP concentrations in children recovering from cardiac surgery.

MATERIALS AND METHODS

We reviewed the records of children who underwent cardiac surgery between January 2008 and January 2009 and had AVP concentrations available as part of a prior prospective study. Doses of hydrocortisone, methylprednisolone, and dexamethasone administered within the first 48 hours after cardiopulmonary bypass were quantitated. Multivariable linear regression was performed to determine if corticosteroids had a significant effect on 48-hour plasma AVP concentration.

RESULTS

Sixty-nine children with plasma AVP concentrations available were reviewed, 34 (49%) of which received corticosteroids within 48 hours after cardiopulmonary bypass. On multivariable regression, greater number of corticosteroid doses but not cumulative corticosteroid dosage was significantly associated with low 48-hour AVP concentration (β=-4.0; 95% confidence intervals, -6.5 to -1.4).

CONCLUSIONS

Children who receive multiple doses of corticosteroids after cardiac surgery, regardless of potency, are likely to have low endogenous AVP concentrations. Children who remain unstable despite corticosteroids may respond favorably to exogenous AVP therapy.

Clinical response to arginine vasopressin therapy after paediatric cardiac surgery

OBJECTIVE

To describe the haemodynamic response of children who receive arginine vasopressin for haemodynamic instability after cardiac surgery and to identify clinical variables associated with a favourable response. Materials and Methods We reviewed patients less than or equal to 6 years undergoing open heart surgery in our institution between January, 2009 and July, 2010 who received arginine vasopressin during the first 7 days post operation. Favourable responders were defined as those in whom blood pressure was increased or maintained and catecholamine score was decreased, or blood pressure was increased by greater than or equal to 10% of baseline and catecholamine score was unchanged at 6 hours following arginine vasopressin initiation.

RESULTS

Of the 34 patients identified, 17 (50%) patients responded favourably to arginine vasopressin. At 6 hours, the mean blood pressure was increased by 32.2% in responders as compared with 4.6% in non-responders, with a p-value less than 0.001. The mean catecholamine score decreased by 30.1% in responders and increased by 7.6% in non-responders, with a p-value less than 0.001. Anthropometric, demographic, and intra-operative variables were similar in both groups, as was maximum dose of arginine vasopressin. The median time after arrival to the intensive care unit at which arginine vasopressin was initiated, however, was later in those who responded, 20 hours as compared with those who did not, 6 hours, with a p-value equal to 0.032.

CONCLUSIONS

Arginine vasopressin therapy led to haemodynamic improvement in only half of the children in this study, and improvement was more likely to occur if arginine vasopressin was initiated after the post-operative night.