Adrenal axis function after high-dose steroid therapy for childhood acute lymphoblastic leukemia

Clinical course of sepsis in children with acute leukemia admitted to the pediatric intensive care unit

OBJECTIVE

To describe the clinical course, resource use, and mortality of patients with leukemia admitted to the pediatric intensive care unit with sepsis and nonsepsis diagnoses over a 10-yr period.

DESIGN

Retrospective analysis.

SETTING

Tertiary medical-surgical pediatric intensive care unit at C.S. Mott Children's Hospital, University of Michigan.

PATIENTS

All patients with leukemia admitted to the pediatric intensive care unit from January 1, 1998, to December 31, 2008.

INTERVENTIONS

None; chart review.

MEASUREMENTS AND MAIN RESULTS

Clinical course was characterized by demographics, leukemia diagnosis, phase of therapy, leukocyte count on admission, presence of sepsis, steroid administration, intensity of care, and Pediatric Risk of Mortality score on admission to the pediatric intensive care unit. The primary outcome was survival to pediatric intensive care unit discharge. Among 68 single admissions to the pediatric intensive care unit with leukemia during the study period, 33 (48.5%) were admitted with sepsis. Admission to the pediatric intensive care unit for sepsis was associated with greater compromise of hemodynamic and renal function and use of stress dose steroids (p = .016), inotropic and/or vasopressor drugs (p = .01), and renal replacement therapy (p = .028) than nonsepsis admission. There was higher mortality among children with sepsis than other diagnoses (52% vs. 17%, p = .004). Also, mortality among children with sepsis was higher among those with acute lymphoblastic leukemia (60% vs. 44%) compared with acute myelogenous leukemia. Administration of stress dose steroids was associated with higher mortality (50% vs. 17%, p = .005) and neutropenia. Patients with acute lymphoblastic leukemia and sepsis showed the greatest mortality and resource use.

CONCLUSIONS

Patients with acute leukemia and sepsis had a much higher mortality rate compared with previously described sepsis mortality rates for the general pediatric intensive care unit patient populations. Patients who received steroids had an increased mortality rate, but given the retrospective nature of this study, we maintain a position of equipoise with regard to this association. Variation in mortality and resource use by leukemia type suggests further research is needed to develop targeted intervention strategies to enhance patient outcomes.

Adrenal suppression: A practical guide to the screening and management of this under-recognized complication of inhaled corticosteroid therapy

Inhaled corticosteroids (ICSs) are the most effective anti-inflammatory agents available for the treatment of asthma and represent the mainstay of therapy for most patients with the disease. Although these medications are considered safe at low-to-moderate doses, safety concerns with prolonged use of high ICS doses remain; among these concerns is the risk of adrenal suppression (AS). AS is a condition characterized by the inability to produce adequate amounts of the glucocorticoid, cortisol, which is critical during periods of physiological stress. It is a proven, yet under-recognized, complication of most forms of glucocorticoid therapy that can persist for up to 1 year after cessation of corticosteroid treatment. If left unnoticed, AS can lead to significant morbidity and even mortality. More than 60 recent cases of AS have been described in the literature and almost all cases have involved children being treated with ≥500 μg/day of fluticasone.

The risk for AS can be minimized through increased awareness and early recognition of at-risk patients, regular patient follow-up to ensure that the lowest effective ICS doses are being utilized to control asthma symptoms, and by choosing an ICS medication with minimal adrenal effects. Screening for AS should be considered in any child with symptoms of AS, children using high ICS doses, or those with a history of prolonged oral corticosteroid use. Cases of AS should be managed in consultation with a pediatric endocrinologist whenever possible. In patients with proven AS, stress steroid dosing during times of illness or surgery is needed to simulate the protective endogenous elevations in cortisol levels that occur with physiological stress.

This article provides an overview of current literature on AS as well as practical recommendations for the prevention, screening and management of this serious complication of ICS therapy.

Duration of adrenal insufficiency during treatment for childhood acute lymphoblastic leukemia

Children with acute lymphoblastic leukemia (ALL) recive high doses of glucocorticosteroid as part of their treatment. This may lead to suppression of the hypothalamic-pituitary-adrenal axis, acute adrenal insufficiency, and ultimately to life-threatening conditions. This study explores the adrenal function in 96 children with ALL treated according to common protocols. After cessation of induction glucocorticosteroid therapy, they received hydrocortisone substitution therapy (10 mg/m/24 h) until an adrenocorticotropic hormone test (250 μg tetracosatide) showed a sufficient adrenal response [plasma (p)-cortisol ≥500 nM]. At the first adrenocorticotropic hormone test, 67% of the patients had adrenal insufficiency. When including these patients in a multivariate model, not adjusting for risk factors, the mean elapsed time between end of induction therapy and adrenal sufficiency was 8.5 months (95% confidence interval: 6.3;10.7). Low 0-minute p-cortisol (P=0.02) and low rise in p-cortisol (P<0.0001) at first test caused a longer time of adrenal insufficiency. In addition, patients with B-cell precursor leukemia reached adrenal sufficiency later than those with T-cell leukemia (P=0.067). As adrenal insufficiency is frequent in children treated for ALL and as they often experience infections and other stressors, the adrenal response should be determined and hydrocortisone substitution therapy should be considered during such episodes in patients with adrenal insufficiency.

Dexamethasone versus prednisone for induction therapy in childhood acute lymphoblastic leukemia: a systematic review and meta-analysis

This systematic review and meta-analysis compared the efficacy and toxicity of dexamethasone (DEX) versus prednisone (PRED) for induction therapy in childhood acute lymphoblastic leukemia (ALL). We searched biomedical literature databases and conference proceedings for randomized controlled trials comparing DEX and PRED during induction therapy for childhood ALL. A total of eight studies were eligible for inclusion in this meta-analysis. DEX, in comparison with PRED, reduced events (that is, death from any cause, refractory or relapsed leukemia, or second malignancy; risk ratio (RR) 0.80; 95% confidence interval (CI), 0.68-0.94) and central nervous system relapse (RR 0.53; 95% CI, 0.44-0.65), but did not alter bone marrow relapse (RR 0.90; 95% CI, 0.69-1.18) or overall mortality (RR 0.91; 95% CI, 0.76-1.09). Patients receiving DEX had a higher risk of mortality during induction (RR 2.31; 95% CI, 1.46-3.66), neuro-psychiatric adverse events (RR 4.55; 95% CI, 2.45-8.46) and myopathy (RR 7.05; 95% CI, 3.00-16.58). There was no statistically significant difference in the risk of osteonecrosis, sepsis, fungal infection, diabetes or pancreatitis. DEX in induction therapy for children with ALL is more efficacious than PRED. However, DEX is also associated with more toxicity, and currently it remains unclear whether short-term superiority of DEX will also result in better overall survival.

Adrenal insufficiency after glucocorticoid withdrawal in children with rheumatic diseases

AIM

 Glucocorticoids (GCs) are often used for the treatment of rheumatic disorders. However, doses are prescribed, which may suppress the hypothalamic-pituitary-adrenal (HPA) axis. After GC withdrawal, recovery of the HPA axis may be delayed putting the patient at risk for adrenal insufficiency. We assessed adrenal function and factors influencing adrenal responsiveness after termination of GC therapy in paediatric patients with rheumatic diseases.

METHODS

  Nineteen patients aged 2-15 years were followed clinically, and adrenal function was tested by low-dose adrenocorticotropic hormone test 1 month after GC withdrawal. In case of adrenal insufficiency by test, re-assessment was performed after 6 and 18 months.

RESULTS

  No signs or symptoms of adrenal insufficiency occurred in any of the patients during and after GC withdrawal. Biochemical examination revealed adrenal insufficiency in 32% (6/19) at 4 weeks and in 11% (2/19) at 20 months after GC withdrawal.

CONCLUSIONS

  In conclusion, current strategies to withdraw GC from paediatric patients with rheumatic diseases are safe. Routine adrenal function testing after GC therapy and withdrawal may not be needed considering the low risk but high number of patients treated with GCs. Nevertheless, awareness of the potential risk and information of patients and their caregivers are crucial to avoid adrenal crisis.

[Is there a risk of steroid-induced adrenal deficit after induction treatment of acute lymphoblastic leukemia?]

The occurrence of eight cases of adrenal deficit in children hospitalized for acute lymphoblastic leukemia (ALL) led us to conduct a prospective study from May 2006 to May 2007 to better characterize this corticoid-induced adrenal deficit. Forty of the 48 patients hospitalized for ALL were given a low-dose Synacthen test (1 μg), a mean 7 days after the induction phase. An adrenal deficit was diagnosed in 27 patients (67.5%). No significant clinical or hematological difference was identified between the "with deficit" (n = 27) and "without deficit" (n = 13) groups. The diagnosis of adrenal deficit was not more common for children who had received dexamethasone (13/19) or prednisone (14/21), or for those who had (19/29) or had not (8/11) experienced corticoid toxicity during induction. The clinical signs suggesting adrenal deficit were identical in the two groups and none of the children presented an acute episode. In biological terms, only hypoprotidemia was significantly more common in patients with adrenal deficit (p = 0.0004). Of 13 patients with a deficit at the end of the induction who had received a 2nd low-dose Synacthène(®) test before intensification no. 1, 3 weeks on average after the end of corticotherapy, only two still had a deficit. Thus, corticoid-induced adrenal deficit is a common complication in children treated for ALL, although it is not highly symptomatic. Most of these children recover normal adrenal function before intensification no. 1, but it does not eliminate the risk of a secondary deficit after other courses of corticotherapy. Systematic repeated Synacthène(®) tests in common practice among children treated for ALL does not seem justified. However, the results of this study encouraged us to propose a hydrocortisone substitution to children treated for ALL in the event of stress.

Anesthetic considerations for the pediatric oncology patient--part 2: systems-based approach to anesthesia

One of the prices paid for chemo- and radiotherapy of cancer in children is damage to the vulnerable and developing healthy tissues of the body. Such damage can exist clinically or subclinically and can become apparent during active antineoplastic treatment or during remission decades later. Furthermore, effects of the tumor itself can significantly impact the physiologic state of the child. The anesthesiologist who cares for children with cancer or for survivors of childhood cancer should understand what effects cancer and its therapy can have on various organ systems. In part two of this three-part review, we review the anesthetic issues associated with childhood cancer. Specifically, this review presents a systems-based approach to the impact from both tumor and its treatment in children, followed by a discussion of the relevant anesthetic considerations.

Corticosteroid physiology and principles of therapy

The adrenal cortex secretes glucocorticoids (GC), mineralocorticoids (MC) and androgens. GC maintain homeostasis, MC regulate fluid and electrolyte balance and adrenal androgens contribute to development of secondary sexual characteristics. Pharmacologic GC therapy is frequently indicated in the pediatric age group. Besides having many important side effects, prolonged high dose systemic GC therapy has a suppressive effect on endogenous steroid production. Therefore, GC therapy should be withdrawn gradually and stopped based on assessment of hypothalamo-pituitary-adrenal (HPA) axis recovery. Patients with HPA axis suppression require physiological replacement of GC along with enhancement of doses during periods of stress. Due to its immunosuppressive effects, issues about safety and efficacy of live virus vaccines in patients receiving systemic high dose GC therapy must be borne in mind.

Low-dose and high-dose adrenocorticotropin testing: indications and shortcomings

PURPOSE OF REVIEW

The 250 microg adrenocorticotropin test (high-dose test) is the most commonly used adrenal stimulation test, though the use of physiologic doses (1.0 microg or 0.5 microg/1.73 m) (low-dose test) has recently gained wider acceptance. These variants and the use of adrenocorticotropin test in the ICU, however, remain controversial. The validity of the low-dose test and the parameters for evaluation of high- and low-dose tests in different situations need reevaluation.

RECENT FINDINGS

In the last few years, numerous studies have used the low-dose test as a single test following previous findings that it is more sensitive and accurate than the high-dose test. It is used mainly in secondary adrenal insufficiency and after treatment with therapeutic glucocorticosteroids to define hypothalamo-pituitary-adrenal suppression. Unless there is a very recent onset of disease, the results are interpreted by most researchers as diagnostic. The treatment of relative adrenal insufficiency, based on delta cortisol, has not yielded proof of correlation between this diagnosis and better prognosis with glucocorticoid treatment.

SUMMARY

For interpretation of an adrenocorticotropin test, only peak - and not delta - cortisol should be used. The use of 240-300 mg of hydrocortisone daily in ICU patients, including septic shock, should be considered as pharmacologic, rather than as a replacement dose. Using the low-dose test for this purpose will lead to further misdiagnosis.