Cortisol response to general anaesthesia for medical imaging in children

Intergenerational Perioperative Neurocognitive Disorder

Accelerated neurocognitive decline after general anesthesia/surgery, also known as perioperative neurocognitive disorder (PND), is a widely recognized public health problem that may affect millions of patients each year. Advanced age, with its increasing prevalence of heightened stress, inflammation, and neurodegenerative alterations, is a consistent contributing factor to the development of PND. Although a strong homeostatic reserve in young adults makes them more resilient to PND, animal data suggest that young adults with pathophysiological conditions characterized by excessive stress and inflammation may be vulnerable to PND, and this altered phenotype may be passed to future offspring (intergenerational PND). The purpose of this narrative review of data in the literature and the authors' own experimental findings in rodents is to draw attention to the possibility of intergenerational PND, a new phenomenon which, if confirmed in humans, may unravel a big new population that may be affected by parental PND. In particular, we discuss the roles of stress, inflammation, and epigenetic alterations in the development of PND. We also discuss experimental findings that demonstrate the effects of surgery, traumatic brain injury, and the general anesthetic sevoflurane that interact to induce persistent dysregulation of the stress response system, inflammation markers, and behavior in young adult male rats and in their future offspring who have neither trauma nor anesthetic exposure (i.e., an animal model of intergenerational PND).

Peri-operative steroid management in the paediatric population

BACKGROUND

Patients with adrenal insufficiency are at risk of adrenal crisis, a potentially life-threatening emergency in the peri-operative period due to their attenuated ability to mount a cortisol response. There is a lack of standardization regarding peri-operative stress-dose glucocorticoids in paediatric clinical practice with the absence of agreed protocols. For the individual patient, the risk of adrenal crisis must be weighed against the potential adverse clinical outcomes associated with unnecessary or supra-physiologic glucocorticoid dosing in susceptible patients. Specific clinical concerns in the paediatric population include osteopenia, growth restriction and increased risk of cardiovascular disease in adulthood. This review aimed to identify and evaluate available literature in the field of peri-operative stress-dose glucocorticoids.

METHODS

A comprehensive literature search was conducted to construct a narrative review.

RESULTS

The outcome of this review identified that paediatric patients, unlike adults, do not show a graded response to surgical stress with implications for glucocorticoid stress dose regimens for general anaesthesia and less invasive surgical procedures. The studies highlight a lack of information on physiological steroid responses to stress situations and differences in the approach to glucocorticoid replacement strategies in the paediatric population.

CONCLUSION

The review identified there is a lack of high-quality paediatric-specific studies evaluating appropriate stress-dose glucocorticoid regimens in paediatric patients with or at risk of adrenal insufficiency. Further research is needed to establish clear evidence-based clinical guidelines for paediatric peri-operative practice regarding steroid stress dosing in adrenal insufficiency. Current knowledge would suggest that a balanced view of risks and benefits should be taken appropriate to the clinical context, to dictate peri-operative stress-dose glucocorticoids use that permits safe perioperative management.

Perioperative stress dose steroid management of children with classical congenital adrenal hyperplasia: Too much or too little?

BACKGROUND

Children with congenital adrenal hyperplasia (CAH) are at risk for adrenal crises in the perioperative period and require higher doses of glucocorticoids. However, there are no specific protocols detailing the appropriate stress dosing required for children with CAH undergoing surgery with anesthesia.

OBJECTIVE

To evaluate CAH patients using our current hydrocortisone stress dose surgical protocol. We hypothesized that current clinical protocols may overestimate the endogenous response to perioperative stress.

STUDY DESIGN

14 children with CAH scheduled to have genital surgery and a control group of 10 unaffected children scheduled to have cardiac or urologic surgery (of a similar duration) were evaluated in a prospective observational study. Urinary free cortisol (UFC) and urinary 17-hydroxycorticosteroids (17-OHCS) per body surface area were measured in the postoperative period.

RESULTS

UFC levels were significantly higher in CAH patients (115.8 ± 24.6 nmol/m²) than in controls (26.5 ± 12.2 nmol/m²), P < 0.05.17-OHCS levels were also higher in CAH patients than in controls (6.5 ± 0.5 nmol/m² vs. 3.4 ± 0.5 nmol/m²), P < 0.05).

CONCLUSION

In the immediate postoperative period, urinary cortisol and its metabolites are significantly higher in pediatric CAH patients receiving stress dose corticosteroids compared to controls. Results suggest that the amount of hydrocortisone given during our stress dose protocol may be higher than physiologic needs. Future dynamic studies are needed to determine appropriate perioperative and postoperative cortisol requirements in pediatric CAH patients in order to develop optimal stress dose regimens.

The potential role of stress and sex steroids in heritable effects of sevoflurane

Most surgical procedures require general anesthesia, which is a reversible deep sedation state lacking all perception. The induction of this state is possible because of complex molecular and neuronal network actions of general anesthetics (GAs) and other pharmacological agents. Laboratory and clinical studies indicate that the effects of GAs may not be completely reversible upon anesthesia withdrawal. The long-term neurocognitive effects of GAs, especially when administered at the extremes of ages, are an increasingly recognized health concern and the subject of extensive laboratory and clinical research. Initial studies in rodents suggest that the adverse effects of GAs, whose actions involve enhancement of GABA type A receptor activity (GABAergic GAs), can also extend to future unexposed offspring. Importantly, experimental findings show that GABAergic GAs may induce heritable effects when administered from the early postnatal period to at least young adulthood, covering nearly all age groups that may have children after exposure to anesthesia. More studies are needed to understand when and how the clinical use of GAs in a large and growing population of patients can result in lower resilience to diseases in the even larger population of their unexposed offspring. This minireview is focused on the authors' published results and data in the literature supporting the notion that GABAergic GAs, in particular sevoflurane, may upregulate systemic levels of stress and sex steroids and alter expressions of genes that are essential for the functioning of these steroid systems. The authors hypothesize that stress and sex steroids are involved in the mediation of sex-specific heritable effects of sevoflurane.

Neuroendocrine, epigenetic, and intergenerational effects of general anesthetics

The progress of modern medicine would be impossible without the use of general anesthetics (GAs). Despite advancements in refining anesthesia approaches, the effects of GAs are not fully reversible upon GA withdrawal. Neurocognitive deficiencies attributed to GA exposure may persist in neonates or endure for weeks to years in the elderly. Human studies on the mechanisms of the long-term adverse effects of GAs are needed to improve the safety of general anesthesia but they are hampered not only by ethical limitations specific to human research, but also by a lack of specific biological markers that can be used in human studies to safely and objectively study such effects. The latter can primarily be attributed to an insufficient understanding of the full range of the biological effects induced by GAs and the molecular mechanisms mediating such effects even in rodents, which are far more extensively studied than any other species. Our most recent experimental findings in rodents suggest that GAs may adversely affect many more people than is currently anticipated. Specifically, we have shown that anesthesia with the commonly used GA sevoflurane induces in exposed animals not only neuroendocrine abnormalities (somatic effects), but also epigenetic reprogramming of germ cells (germ cell effects). The latter may pass the neurobehavioral effects of parental sevoflurane exposure to the offspring, who may be affected even at levels of anesthesia that are not harmful to the exposed parents. The large number of patients who require general anesthesia, the even larger number of their future unexposed offspring whose health may be affected, and a growing number of neurodevelopmental disorders of unknown etiology underscore the translational importance of investigating the intergenerational effects of GAs. In this mini review, we discuss emerging experimental findings on neuroendocrine, epigenetic, and intergenerational effects of GAs.

Roles of Testosterone and Estradiol in Mediation of Acute Neuroendocrine and Electroencephalographic Effects of Sevoflurane During the Sensitive Period in Rats

Testosterone (T), predominantly acting through its derivative 17β-estradiol (E2), regulates the brain's sexual differentiation in rodents during the perinatal sensitive period, which mirrors the window of vulnerability to the adverse effects of general anesthetics. The mechanisms of anesthesia's adverse effects are poorly understood. We investigated whether sevoflurane alters T and E2 levels and whether they contribute to sevoflurane's acute adverse effects in postnatal day 5 Sprague-Dawley rats. The rats underwent electroencephalography recordings for 2 h of baseline activity or for 1 h before and another hour during 2.1% sevoflurane exposure, followed by collection of trunk blood and brain tissue. Pharmacological agents, including the GABA type A receptor inhibitor bicuculline and the aromatase inhibitor formestane, were administered 30 min before sevoflurane anesthesia. Sevoflurane increased serum T levels in males only. All other effects of sevoflurane were similar in both sexes, including increases in serum levels of E2, hypothalamic mRNA levels of aromatase, estrogen receptor α (Erα) [not estrogen receptor β (Erβ)], Na⁺-K⁺-Cl^- cotransporter (Nkcc1)/K⁺-Cl^- cotransporter (Kcc2) mRNA ratio, electroencephalography-detectable seizures, and stress-like corticosterone secretion. Bicuculline and formestane alleviated these effects, except the T level increases. The ERα antagonist MPP, but not the ERβ antagonist PHTPP, reduced electroencephalography-detectable seizures and normalized the Nkcc1/Kcc2 mRNA ratio. Collectively, sevoflurane exacerbates levels of T in males and E2 in both sexes during the period of their organizational effects in rodents. Sevoflurane acts through GABA_AR-mediated, systemic T-independent elevation of E2 to cause electroencephalography-detectable seizures, stress-like corticosterone secretion, and changes in the expression of genes critical for brain development.

Perioperative care of congenital adrenal hyperplasia - a disparity of physician practices in Canada

Background

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is the most common cause of primary adrenal insufficiency in children. Current guidelines recommend the use of perioperative stress dose (supraphysiologic) glucocorticoids for children with CAH undergoing anesthesia, although a perceived difference in practice patterns among Canadian pediatric subspecialists prompted an assessment of perioperative glucocorticoid administration.

Methods

We performed a cross-sectional survey of Canadian Pediatric Anesthesia Society (CPAS) and Canadian Pediatric Endocrine Group (CPEG) members via membership email lists to assess reported practice patterns to select clinical scenarios.

Results

Responses were collected from 49 anesthesiologists and 37 pediatric endocrinologists. Less than half of anesthesiologists reported they would provide stress dose corticosteroids for patients undergoing cystoscopy while a significant majority of pediatric endocrinologists reported they would recommend stress dose corticosteroid administration (45% vs 92% respectively, p < 0.0001). Twenty-one percent of anesthesiologists reported they would not provide stress dose corticosteroids for patients undergoing laparotomy. Pediatric endocrinologists reported they were more likely to refer to guidelines for management of stress dose steroids (84% vs 51%, p < 0.001), with many Canadian pediatric endocrinologists reporting to use institution specific guidelines.

Conclusions

Our results demonstrate a clear difference in the reported approach to perioperative stress dose steroids between pediatric anesthesiologists and pediatric endocrinologists which may impact patient care. Further dialogue is required to address this apparent discrepancy in practice patterns and future research is needed to provide evidence-based practice recommendations.

Electronic supplementary material

The online version of this article (10.1186/s13633-018-0063-4) contains supplementary material, which is available to authorized users.

The diagnosis and treatment of adrenal insufficiency during childhood and adolescence

The diagnosis and treatment of adrenal insufficiency in childhood and adolescence poses a number of challenges. Clinical features of chronic adrenal insufficiency are vague and non-specific, and mimic many other causes of chronic ill health. A range of diagnostic tests are available for the assessment of adrenal function, all of which have advantages and disadvantages. Cortisol responses to these tests may vary with age and between genders. Knowledge of normal cortisol levels during health and ill health in childhood is also limited, and the cortisol replacement therapies available in clinical practice enable only crude mimicry of physiological patterns of cortisol secretion. An awareness of the limitations of diagnostic tests and treatments is important, and critical clinical assessment, integrating clinical and biochemical data, is essential for the diagnosis and treatment of children with suspected adrenal insufficiency. The aim of this review is to draw on data from clinical studies to inform a pragmatic approach to the child presenting with symptoms of chronic adrenal insufficiency. Clinical features of primary and secondary adrenal insufficiency, and syndromes associated with these diagnoses are described. Factors to consider when selecting a diagnostic test of adrenal function and interpretation of test results are considered. Finally, the limitations of cortisol replacement therapy are also discussed.

Diagnosis and Treatment of Primary Adrenal Insufficiency: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

This clinical practice guideline addresses the diagnosis and treatment of primary adrenal insufficiency.

PARTICIPANTS

The Task Force included a chair, selected by The Clinical Guidelines Subcommittee of the Endocrine Society, eight additional clinicians experienced with the disease, a methodologist, and a medical writer. The co-sponsoring associations (European Society of Endocrinology and the American Association for Clinical Chemistry) had participating members. The Task Force received no corporate funding or remuneration in connection with this review.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to determine the strength of recommendations and the quality of evidence.

CONSENSUS PROCESS

The evidence used to formulate recommendations was derived from two commissioned systematic reviews as well as other published systematic reviews and studies identified by the Task Force. The guideline was reviewed and approved sequentially by the Endocrine Society's Clinical Guidelines Subcommittee and Clinical Affairs Core Committee, members responding to a web posting, and the Endocrine Society Council. At each stage, the Task Force incorporated changes in response to written comments.

CONCLUSIONS

We recommend diagnostic tests for the exclusion of primary adrenal insufficiency in all patients with indicative clinical symptoms or signs. In particular, we suggest a low diagnostic (and therapeutic) threshold in acutely ill patients, as well as in patients with predisposing factors. This is also recommended for pregnant women with unexplained persistent nausea, fatigue, and hypotension. We recommend a short corticotropin test (250 μg) as the "gold standard" diagnostic tool to establish the diagnosis. If a short corticotropin test is not possible in the first instance, we recommend an initial screening procedure comprising the measurement of morning plasma ACTH and cortisol levels. Diagnosis of the underlying cause should include a validated assay of autoantibodies against 21-hydroxylase. In autoantibody-negative individuals, other causes should be sought. We recommend once-daily fludrocortisone (median, 0.1 mg) and hydrocortisone (15-25 mg/d) or cortisone acetate replacement (20-35 mg/d) applied in two to three daily doses in adults. In children, hydrocortisone (∼8 mg/m(2)/d) is recommended. Patients should be educated about stress dosing and equipped with a steroid card and glucocorticoid preparation for parenteral emergency administration. Follow-up should aim at monitoring appropriate dosing of corticosteroids and associated autoimmune diseases, particularly autoimmune thyroid disease.

Cortisol response to operative stress with anesthesia in healthy children

BACKGROUND

Supraphysiological "stress dosing" is generally given to adrenally insufficient patients undergoing operative procedures and/or general anesthesia. However, the normal responses of cortisol to surgery are poorly documented, especially in small children. Recent studies in adults suggest that massive glucocorticoid dosing is not needed, especially in minimally invasive surgery.

OBJECTIVE

We sought to characterize the normal cortisol secretion rate in healthy children undergoing minimally and moderately invasive urological procedures.

DESIGN AND SETTING

This was a prospective observational study conducted at a tertiary referral center.

PATIENTS

Thirty healthy children, ages 5 months to 6 years, were studied undergoing elective urological procedures.

METHODS

Procedures were performed by a single surgeon; anesthesia was by a standard protocol. Sera were obtained at 5 points: iv catheter placement, intubation, 50% completion of surgery, anesthesia reversal, and 1 hour postoperative. Cortisol and cortisone were quantitated by liquid chromatography-tandem mass spectrometry.

RESULTS

Group mean cortisol values ranged from 4.21 to 5.71 μg/dL across the 5 time points; none of these mean values differed significantly (P < .05). There were no differences according to age, time of procedure, caudal anesthesia, and moderate vs minimally invasive procedures; 3 patients had higher values. There was a modest diminution in cortisone across the 5 time points.

CONCLUSIONS

Minimal and moderately invasive urological procedures do not result in a cortisol stress response in healthy children. Peak cortisol levels were seen 1 hour postoperatively. These data suggest that current guidelines for stress dosing in adrenally insufficient patients substantially exceed physiological requirements during minimally invasive procedures.

The perioperative dialogue reduces postoperative stress in children undergoing day surgery as confirmed by salivary cortisol

AIM

To evaluate the efficacy of 'the perioperative dialogue (PD)' by analyzing salivary cortisol, in 5- to 11-year-old children undergoing day surgery.

BACKGROUND

  To deal with anxiety prior to investigations and/or procedures, children need to be confident and informed about what is going to happen. Therefore, intervention strategies should be initiated before admission to hospital.

METHODS AND MATERIALS

  Children (n = 93), 79 boys and 14 girls, scheduled for elective day surgery requiring general anesthesia were randomly recruited into three groups: (i) standard perioperative care (n = 31), (ii) standard perioperative care including preoperative information (n = 31), and (iii) the PD (n = 31). Saliva was sampled for cortisol analysis at specific time points during the pre- and perioperative procedures.

RESULTS

  The children who received the PD had significantly lower (P = 0.003) salivary cortisol concentrations postoperatively. Moreover, it continuously decreased during the day of surgery compared with the other two groups (P < 0.01). Among the children who received analgesics, the PD group received significantly less morphine (P = 0.014) related to bodyweight: the mean dose was 0.1 mg·kg(-1) (n = 9) in the control group vs 0.04 mg·kg(-1) (n = 6) in the PD group. Irrespective of group, there was a positive correlation between the children's morphine consumption and salivary cortisol concentration (r = 0.56; P = 0.038). The W-B scale score was higher in the group that received morphine (median = 3 vs median=1; P = 0.001).

CONCLUSIONS

  The PD's caring, continuity, and on-going dialogues were associated with low concentrations of salivary cortisol postoperatively and reduced morphine consumption and thus appears to be a valuable complement to standard perioperative care in children undergoing day surgery.