Total and free cortisol responses and their relation to outcomes after cardiopulmonary bypass in infants

SNARE-ing the Reason for Post-Cardiac Surgery Critical Illness-Related Corticosteroid Insufficiency

Critical illness-related corticosteroid insufficiency (CIRCI) can cause hemodynamic instability in neonates after congenital heart surgery with manifestations that increase morbidity and potential mortality. We retrospectively reviewed neonates who underwent cardiac surgery between August 2018 and July 2020 at a freestanding children's hospital, had next-generation sequencing performed, and had their cortisol levels drawn as standard clinical care after cardiac surgery. The groups were defined as CIRCI (with a cortisol level ≤ 4.5 mcg/dL) and non-CIRCI (level > 4.5 mcg/dL). The CIRCI group (n = 8) had a 100% incidence of heterozygous gene mutation on STX1A with splicing or loss of function, and this mutation was not found in the non-CIRCI group (n = 8). Additional gene mutations were found in the CIRCI group on RAB6A, ABCA3, SIDT2, and LILRB3, with no incidence in the non-CIRCI group. Three additional mutations were found across the CIRCI group in INPPL1 and FAM189A2 (both splicing and missense), with 12-25% of patients in the non-CIRCI group also displaying these mutations. Novel genetic abnormalities were seen in neonates with symptoms of CIRCI with potential cardiac implications from a gene mutation for STX1A. Compounding effects of additional gene mutations need to be confirmed and explored for potential predisposition to hemodynamic instability during times of stress.

Steroid Use for Management of Vasoactive Resistant Shock in Pediatric Cardiac Intensive Care Patients: Experience of the Consortium of Congenital Cardiac Care-Measurement of Nursing Practice

BACKGROUND

Although a variety of doses and duration of hydrocortisone have been reported as a treatment modality for congenital heart surgery patients with refractory hypotension, there remains a lack of understanding of the clinical use in pediatric cardiac programs.

OBJECTIVES

The aim of this study was to describe the current practice of steroid use for refractory hypotension in postoperative congenital heart surgery patients.

METHOD

Survey participants were recruited from the Consortium of Congenital Cardiac Care-Measurement of Nursing Practice. The survey focused on 4 areas: diagnosis, intervention, duration of therapy, and clinical decision making. Data were summarized using descriptive statistics.

RESULTS

Among the programs, 24 of 31 (77%) responded, with 21 (95%) using hydrocortisone as a treatment modality. Most, 20 (83%), reported no written clinical guideline for the use of hydrocortisone. Variation in dosing existed as 3 centers (14%) use 50 mg/m2/d, 6 (29%) use 100 mg/m2/d, and 8 (38%) indicated that dosing varies by provider.

DISCUSSION

Nearly all centers reported using hydrocortisone for the treatment of hypotension refractory to fluid resuscitation and vasoactive medications. Substantial variation in practice exists in areas of diagnosis, dosing, and duration of hydrocortisone. More research is needed to develop a clinical practice guideline to standardize practice.

Patterns and Determinants of Change in Cortisol Levels and Thyroid Function as a Function of Cardiac Risk in Children Undergoing Cardiac Surgery

Background

Children undergoing cardiac surgery with cardiopulmonary bypass (CPB) are exposed to the risk of hormonal imbalances resulting from acute stress, which may eventually result in high postoperative mortality and morbidity.

Objective

We assessed adrenal and thyroid hormonal changes and their determinants following cardiac surgery in children and explored their prognostic value in predicting cardiac outcomes. Study Design and Methods. A prospective cohort study was conducted at King Abdulaziz University Hospital (KAUH), between 2017 and 2018. The study involved 46 children aged 14 years or younger who underwent elective cardiac surgery with cardiopulmonary bypass. Serum levels of cortisol, TSH, fT3, and fT4 were measured preoperatively and 24, 48, and 72 hours after surgery. The cardiac risk was assessed using the risk adjustment for congenital heart surgery (RACHS) scale. A composite cardiovascular outcome was analyzed as a numerical variable and calculated as the number of cardiovascular events.

Results

Overall, the changes in thyroid function parameters resulted in a U-shaped curve, while cortisol levels yielded a bell-shaped curve. The most significant changes occurred at 24 hours postop, including a decrease in mean TSH by 2.08 μIU/L (p < 0.001), fT3 by 2.39 pmol/L (p < 0.001), and fT4 by 2.45 pmol/L (p < 0.001) and an increase in cortisol levels by 406.48 nmol/L (p < 0.001) with respect to the baseline. Cortisol concentration peaked higher and recovered slower among patients with high cardiac risk than their counterparts. Cardiovascular outcomes were independently predicted by the extent of the decline in fT4 and TSH at 48 and 72 hours postop, with reference to the baseline, and by the cortisol level at 24 h postop, independent of the baseline, besides the RACHS category.

Conclusion

Cardiac surgery among children yields a high adrenocortical response and a high incidence of nonthyroidal illness syndrome, increasing cardiovascular risk. A preventive management strategy involves improving surgical techniques to minimize trauma-related stress.

Skin-to-Skin Care Is a Safe and Effective Comfort Measure for Infants Before and After Neonatal Cardiac Surgery

OBJECTIVES

To determine the effect of skin-to-skin care on stress, pain, behavioral organization, and physiologic stability of infants with critical congenital heart disease before and after neonatal cardiac surgery.

DESIGN

A baseline response-paired design was used, with infants acting as their own controls before, during, and after skin-to-skin care at two distinct time points: once in the preoperative period (T1) and once in the postoperative period (T2).

SETTING

Cardiac ICU and step-down unit in a large metropolitan freestanding children's hospital.

SUBJECTS

Convenience sample of 30 infants admitted preoperatively for critical congenital heart disease.

INTERVENTIONS

Eligible infants were placed into skin-to-skin care for 1 hour with their biological mothers once each at T1 and T2.

MEASUREMENTS AND MAIN RESULTS

Measurements of stress (salivary cortisol), pain and behavior state (COMFORT scale), and physiologic stability (vital signs) were assessed immediately before skin-to-skin care, 30 minutes into skin-to-skin care, and 30 minutes after skin-to-skin care ended.At both T1 and T2, infant pain scores were significantly decreased (p < 0.0001) and infants moved into a calmer behavior state (p < 0.0001) during skin-to-skin care as compared to baseline. At T1, infants also had significantly reduced heart rate (p = 0.002) and respiratory rate (p < 0.0001) and increased systolic blood pressure (p = 0.033) during skin-to-skin care. At both T1 and T2, infant cortisol remained stable and unchanged from pre-skin-to-skin care to during skin-to-skin care (p = 0.096 and p = 0.356, respectively), and significantly increased from during skin-to-skin care to post-skin-to-skin care (p = 0.001 and p = 0.023, respectively). Exploratory analysis revealed differences in cortisol reactivity for infants with higher baseline cortisol (> 0.3 μg/dL) versus lower (≤ 0.3 μg/dL) prior to skin-to-skin care. Infants with higher baseline cortisol at T2 experienced significantly reduced cortisol during skin-to-skin care (p = 0.025). No significant differences in demographics or baseline variables were found between infants in either group.

CONCLUSIONS

Skin-to-skin care is a low-cost, low-risk intervention that promotes comfort and supports physiologic stability in infants before and after neonatal cardiac surgery.

Adrenal insufficiency in neonates undergoing cardiopulmonary bypass and postoperative hypothalamic-pituitary-adrenal function after prophylactic glucocorticoids

OBJECTIVES

Determine incidence of preoperative adrenal insufficiency in neonates >35 weeks gestation with congenital heart disease undergoing cardiothoracic surgery with bypass and effects of prophylactic methylprednisolone on postoperative hypothalamic-pituitary-adrenal function and hemodynamic stability.

DESIGN

Prospective observational study in 36 neonates with preoperative adrenocorticotrophic hormone stimulation tests and serial total cortisol and adrenocorticotrophic hormone measurements before and after surgery. Data analyses: analysis of variance and regression.

RESULTS

Baseline circulating adrenocorticotrophic hormone and cortisol were unchanged 4-20 days postnatal (P > 0.1); however, cortisol levels rose with increasing adrenocorticotrophic hormone, P = 0.02. Ten neonates (29%) demonstrated preoperative adrenal insufficiency (∆cortisol ≤9 µg/dl); one had postoperative hemodynamic instability. Growth-restricted neonates had lower baseline cortisol, but normal stimulation tests and responded well to surgical stresses. Seventy-five percent of neonates receiving perioperative methylprednisolone demonstrated postoperative hypothalamic-pituitary-adrenal inhibition.

CONCLUSION

Adrenal insufficiency appears common in neonates >35 weeks gestation with congenital heart disease, but did not contribute to postoperative hemodynamic instability despite hypothalamic-pituitary-adrenal inhibition.

Characterization of the Glucocorticoid Receptor in Children Undergoing Cardiac Surgery

OBJECTIVES

Postoperative administration of corticosteroids is common practice for managing catecholamine refractory low cardiac output syndrome. Since corticosteroid activity is dependent on the glucocorticoid receptor, we sought to characterize glucocorticoid receptor levels in children undergoing cardiac surgery and examined the association between glucocorticoid receptor levels and cardiovascular dysfunction.

DESIGN

Prospective observational cohort study.

SETTING

Large, tertiary pediatric cardiac center.

SUBJECTS

Children undergoing corrective or palliative cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A prospective observational cohort study was conducted in 83 children with congenital heart disease. Total glucocorticoid receptor levels were measured in the peripheral WBCs using flow cytometry. In addition, blood samples were collected for total cortisol levels. The primary outcome studied was the time to being inotrope free. An increase in glucocorticoid receptor level from postoperative day 1 to postoperative day 3 was associated with a longer time to being inotrope free (hazard ratio, 0.49 [0.29-0.81]; p = 0.01) in the univariate analysis. This association remained significant after adjusting for age, weight, cardiopulmonary bypass time, cross clamp time, Risk Adjustment for Congenital Heart Surgery-1 score, and postoperative steroid use (hazard ratio, 0.53 [0.29-0.99]; p = 0.05). Postoperative day 3 glucocorticoid receptor level showed a trend to have longer time to being inotrope free (hazard ratio, 0.66 [0.42-1.02]; p = 0.0.06). The cortisol levels minimally increased during the study duration and did not correlate with glucocorticoid receptor levels.

CONCLUSIONS

Increasing glucocorticoid receptor levels in peripheral WBCs of children undergoing cardiac surgery are associated with a longer time to being inotrope free. Cortisol levels minimally increased during the study duration. These results suggest that exposure to high-dose perioperative corticosteroids may suppress the hypothalamic-pituitary-adrenal axis leading to increase in glucocorticoid receptor levels in response to a low cortisol environment. Further studies are required to better delineate the interplay between glucocorticoid receptor levels, cortisol levels, corticosteroid exposure, and postoperative inotropic requirements.