Adrenocortical insufficiency after pituitary surgery: an audit of the reliability of the conventional short synacthen test

Perioperative growth hormone levels as an early predictor of new-onset secondary adrenal insufficiency following transsphenoidal pituitary tumor resection

OBJECTIVE

This study aims to predict new-onset secondary adrenal insufficiency (NOSAI) after transsphenoidal pituitary tumor resection surgery using perioperative growth hormone (GH) and prolactin (PRL) levels, among other factors.

METHODS

A cohort of 124 adult patients who underwent transsphenoidal resection for non-functioning pituitary adenoma, with routine perioperative glucocorticoid use, was used to develop the predictive regression model. An additional 46 patients served as the validation cohort. Generalized additive models were used to identify optimal cut-off points for the variables.

RESULTS

The GH level on postoperative day one (POD1) can be a simple predictor by implementing a cut-off point of 0.41 ng/ml. A value ≤ 0.41 ng/mL predicted NOSAI with 0.6316 sensitivity and 0.7810 specificity for the original cohort and 1.0000 sensitivity and 0.7143 specificity for the validation cohort. The multiple logistic regression model included perioperative PRL level difference, perioperative GH level difference, intraoperative cerebrospinal fluid (CSF) leakage, tumor size, and the combined effect of diabetes insipidus (DI) and relative perioperative GH level difference. The areas under the receiver operating characteristic curves were 0.9410 (original cohort) and 0.9494 (validation cohort) for the regression model.

CONCLUSION

Early morning GH level on POD1 can predict NOSAI with fair accuracy when perioperative stress dose glucocorticoid is administered. Prediction accuracy can be improved by considering CSF leakage, DI, and perioperative changes in GH and PRL in the final regression model.

Pituitary function after transsphenoidal surgery including measurement of basal morning cortisol as predictor of adrenal insufficiency

INTRODUCTION

Patients with pituitary adenomas undergoing transsphenoidal surgery require pre- and post-surgery examination of pituitary hormones. There is currently no consensus on how to evaluate the adrenal axis post-surgery. The aims of this study were to investigate factors that may predict postoperative adrenal insufficiency (AI) and to investigate the overall effect of transsphenoidal surgery on pituitary function.

METHODS

One hundred and forty-three consecutive patients who had undergone transsphenoidal surgery for pituitary adenomas were included. Data on tumour size, pituitary function pre-surgery, plasma basal cortisol measured within 48 h post-surgery and pituitary function 6 months post-surgery were collected. Patients with AI prior to surgery, perioperative glucocorticoid treatment, Cushing's disease and no re-evaluation after 1 month were excluded (n = 93) in the basal cortisol analysis.

RESULTS

Low plasma basal cortisol post-surgery, tumour size and previous pituitary surgery were predictors of AI (all P < 0.05). A basal cortisol cut-off concentration of 300 nmol/L predicted AI 6 months post-surgery with sensitivity and negative predictive value of 100%, specificity of 81% and positive predictive value of 25%. New gonadal, thyroid and adrenal axis insufficiencies accounted for 2, 10 and 10%, respectively. The corresponding recovery rates were 17, 7 and 24%, respectively.

CONCLUSION

Transsphenoidal surgery had an overall beneficial effect on pituitary endocrine function. Low basal plasma cortisol measured within 48 h after surgery, tumour size and previous surgery were identified as risk factors for AI. Measurement of basal cortisol post-surgery may help to identify patients at risk of developing AI.

The relationship between early post-operative ACTH / cortisol following pituitary surgery and long-term glucocorticoid requirement - Do ultradian rhythms matter?

OBJECTIVE

To determine whether early (4-8h) post-operative ACTH after trans-sphenoidal surgery (TSS) predicts long-term hypothalamic-pituitary-adrenal (HPA) axis function and to investigate early morning day 1 ACTH/cortisol variability using rapid sampling.

DESIGN

Prospective observational study.

METHODS

Participants undergoing TSS were included; those treated with glucocorticoids pre-operatively received 100 mg intravenous hydrocortisone on anaesthetic induction. ACTH and cortisol were measured post-operatively at + 4h and + 8h after induction and on day 1 every 10 minutes between 0700h and 0900h.

PRIMARY OUTCOME

glucocorticoid requirement at 6 months.

RESULTS

Nineteen participants (10F, 9M): 6/19 (32%) were treated with replacement glucocorticoids pre-operatively; 4 had ceased by 6 weeks post-operatively. One patient developed new hypopituitarism post-operatively meaning 3/19 (16%) required glucocorticoids at 6 months. Post-operative + 4h ACTH < 14.3 pmol/L (65 ng/L) predicted secondary adrenal insufficiency (SAI) (sensitivity 100%, specificity 75%), whilst no participant with a post-operative + 4h ACTH ≥ 14.3 pmol/L (65 ng/L) required glucocorticoids at 6 months. Day 1 ACTH and cortisol showed a significant circadian fall between 0700h-0900h; ACTH 4.2 pmol/L (IQR 2.9-5.9) to 3.7 pmol/L (IQR 2.9-5.1) P = .006 and cortisol 549 nmol/L (IQR 337-618) to 439 nmol/L (IQR 315-606) P < .001, with clinically insignificant ultradian secretory pulses.

CONCLUSIONS

No participant with a post-operative + 4h ACTH ≥ 14.3 pmol/L (65 ng/L) required glucocorticoids at 6 months; however, given only 3/19 participants had the primary outcome of interest, this must be confirmed in a larger cohort. The timing of a day 1 morning cortisol between 0700h and 0900h influences the accuracy of a single cut-off to diagnose SAI after pituitary surgery.

Second-Day Morning Cortisol Levels after Transsphenoidal Surgery Are Accurate Predictors of Secondary Adrenal Insufficiency with Diagnostic Cut-Offs Similar to Those in Non-Stressed Conditions

INTRODUCTION

Multiple studies tried to identify cortisol cut-offs after pituitary surgery that could accurately assess hypothalamic-pituitary-adrenal (HPA) axis function; however, there is no consensus nowadays. This study aimed to evaluate the accuracy of morning cortisol after transsphenoidal surgery in predicting long-term secondary adrenal insufficiency.

METHODS

In our tertiary center, we prospectively determined first- and second-day cortisol after transsphenoidal surgery in 92 patients without preoperative adrenal -insufficiency and not treated with glucocorticoids perioperatively. Definitive diagnosis of secondary adrenal insufficiency was obtained with re-evaluation 3 months after trans-sphenoidal surgery and clinical follow-up of at least 1 year.

RESULTS

Ten patients (10.8%) developed long-term postoperative secondary adrenal insufficiency. The ROC curves demonstrated that first-day cortisol had a moderate diagnostic accuracy, while a second-day cortisol ≤9.3 µg/dL (257 nmol/L) showed the best performance in predicting adrenal insufficiency (sensitivity [Se] 88.9%, specificity [Sp] 86.9%, AUC 0.921). Moreover, a second-day cortisol ≤3.2 µg/dL (89 nmol/L) was able to diagnose adrenal insufficiency in 100% of cases (Se 22.2%, Sp 100%) and >14 µg/dL (386 nmol/L) was able to exclude ACTH deficiency (Se 100%, Sp 57.4%).

CONCLUSIONS

Adrenal function can be carefully studied on the second day after pituitary surgery, using cut-off values that international guidelines suggested for non-stressed conditions. In fact, second-day cortisol levels ≤3.2 μg/dL (89 nmol/L) and >14 μg/dL (386 nmol/L) are diagnostic of secondary adrenal insufficiency and normal function, respectively. We also suggest performing a definitive re-evaluation with an HPA axis stimulation test when second-day cortisol values are between 3.3 and 14 μg/dL (90-386 nmol/L).

Diagnostic performance of morning serum cortisol as an alternative to short synacthen test for the assessment of adrenal reserve; a retrospective study

OBJECTIVE

The short synacthen test (SST) is widely used across the UK to assess adrenal reserve. The main objective of our study was to determine the morning serum cortisol level that will predict adrenal insufficiency (AI) thus reducing our reliance on SST.

DESIGN

This was a single centre retrospective study of 393 SST tests measuring 0 and 60 min cortisol levels after administration of 250 μg of synacthen (synthetic ACTH).

PATIENTS AND METHODS

All the SST tests for patients suspected of primary or secondary AI between April 2016 and October 2018 were included in this study. We used serum to determine circulating cortisol by a newer generation competitive electrochemiluminescence immunoassay (ECLIA) (Roche Diagnostics). A post-ACTH cortisol response of ≥420 nmol/L at 60 min was considered adequate to rule out AI. The data were analysed to ascertain the relationship between 0 min and 60 min serum cortisol.

RESULTS

A total of 393 SST results were included in this study. Overall, a total of 332 (84.5%) subjects achieved sufficient serum cortisol level at 60 min, while 61 subjects (15.5%) showed insufficient response. Using the logistic regression, we determined that a morning basal serum cortisol level of ≥354 nmol/L was able to predict normal adrenal function with 100% sensitivity. We were unable to find a lower cut-off value below which SST will not be required. By using this proposed cut-off point, approximately 37% of the SSTs tests could be avoided.

CONCLUSIONS

Basal morning serum cortisol can be safely used as a first step in the evaluation of patients with suspected AI. This will enhance the number of patients being screened for this condition.

Cut-off values for sufficient cortisol response to low dose Short Synacthen Test after surgery for non-functioning pituitary adenoma

OBJECTIVE

The aim was to study the prevalence of secondary adrenal insufficiency before and after surgery for non-functioning pituitary adenomas, as well as determine risk factors for developing secondary adrenal insufficiency. A secondary aim was to determine adequate p-cortisol response to a 1-μg Short Synacthen Test after surgery.

DESIGN

Longitudinal cohort study.

METHODS

One hundred seventeen patients (52/65 females/males, age 59 years) undergoing primary surgery for clinically non-functioning pituitary adenomas were included. P-cortisol was measured in morning blood samples. Three months after surgery, a Short Synacthen Test was performed.

RESULTS

All tumours were macroadenomas (mean size 26.9 mm, range 13-61 mm). The surgical indications were visual impairment (93), tumour growth (16), pituitary apoplexy (6) and headache (2). Before surgery, 17% of the patients had secondary adrenal insufficiency (SAI), decreasing to 15% 3 months postoperatively. Risk of SAI was increased in patients operated for pituitary apoplexy (p < 0.001), while age, sex, tumour size and complication rate were not different from the remaining cohort. Three months after surgery, all patients with baseline p-cortisol ≥ 172 nmol/l (6.2 μg/dl) and peak p-cortisol during Short Synacthen Test ≥ 320 nmol/l (11.6 μg/dl) tapered cortisone unproblematically. In patients with intact hypothalamic-pituitary-adrenal axis, p-cortisol peaked < 500 nmol/l (18.1 μg/dl) during Short Synacthen Test in 48% of patient.

CONCLUSION

Pituitary surgery is safe and transsphenoidal surgery rarely causes new SAI. Relying solely on morning p-cortisol for diagnosing secondary adrenal insufficiency gives false positives and the Short Synacthen Test remains useful. A peak p-cortisol ≥ 320 during (11.6 μg/dl) Short Synacthen Test indicates a sufficient response, while < 309 nmol/l (11.2 μg/dl) indicates secondary adrenal insufficiency.

Predictive Factors of Adrenal Insufficiency in Outpatients with Indeterminate Serum Cortisol Levels: A Retrospective Study

Background and Objectives: To diagnose adrenal insufficiency (AI), adrenocorticotropic hormone (ACTH) stimulation tests may need to be performed, but those tests may not be available in some institutions. In addition, they may not be necessary for some patients. The objective of this study was to identify clinical and biochemical factors that could facilitate AI diagnosis in outpatient departments and decrease the number of unnecessary dynamic tests. Materials and Methods: This seven-year retrospective study was performed in a tertiary care medical center. A total of 517 patients who had undergone ACTH stimulation tests in the outpatient department were identified. AI was described as a peak serum cortisol level of <18 µg/dL at 30 or 60 min after stimulation. The associations between clinical factors, biochemical factors, and AI were analyzed using the Poisson regression model and reported by the risk ratio (RR). Results: AI was identified in 128 patients (24.7%). Significant predictive factors for the diagnosis of AI were chronic kidney disease (RR = 2.52, p < 0.001), Cushingoid appearance (RR = 3.44, p < 0.001), nausea and/or vomiting (RR = 1.84, p = 0.003), fatigue (RR = 1.23, p < 0.001), serum basal cortisol <9 µg/dL (RR = 3.36, p < 0.001), serum cholesterol <150 mg/dL (RR = 1.26, p < 0.001), and serum sodium <135 mEq/L (RR = 1.09, p = 0.001). The predictive ability of the model was 83% based on the area under the curve. Conclusion: The easy-to-obtain clinical and biochemical factors identified may facilitate AI diagnosis and help identify patients with suspected AI. Using these factors in clinical practice may also reduce the number of nonessential dynamic tests for AI.

Early postoperative HPA-axis testing after pituitary tumor surgery: reliability and safety of basal cortisol and CRH test

PURPOSE

To assess the reliability and safety of a postsurgical evaluation strategy of adrenal function using CRH stimulation and basal cortisol concentrations after transsphenoidal pituitary surgery.

METHODS

Retrospective cohort study of all patients undergoing endoscopic transsphenoidal surgery from 2010 to 2017, in whom early postoperative basal cortisol and/or CRH-stimulated cortisol secretion were available, including confirmation of adrenal function during follow-up. Patients with Cushing's disease were excluded. Optimal test performances were assessed using ROC analysis.

RESULTS

A total of 156 patients were included. Sensitivity and specificity of the CRH test were 78% and 90%, respectively, and 86% and 92% for basal cortisol, respectively, using an optimal cutoff of 220 nmol/L. Eight patients had false-negative test results with the CRH test (normal test but adrenal insufficient at follow-up), and six patients with basal cortisol, the majority of which had multiple pituitary hormone deficiencies and fluid imbalances. No clinical adverse events occurred in patients with false-negative test results. The diagnostic performance of a single basal cortisol measurement was superior to the CRH test.

CONCLUSIONS

The early postoperative basal cortisol is a safe and simple measurement to guide (dis)continuation of hydrocortisone replacement. However, disturbing factors, e.g., sodium balance disorders, contraceptives, untreated hypopituitarism, and illness impact the interpretation and in those cases this measure is unreliable. We propose an algorithm in which hydrocortisone replacement at discharge is based on basal cortisol <220 nmol/L on postoperative day 2 or 3 in a stable condition.

Do we need 30 min cortisol measurement in the short synacthen test: a retrospective study

OBJECTIVE

The short synacthen test (SST) is widely used across the UK to assess adrenal reserve but there remains no consensus on the timing of cortisol sampling to help diagnose adrenal insufficiency. The main objective of our study was to see if both 30 and 60 min sample are required following administration of synacthen to investigate suspected adrenal insufficiency (AI).

DESIGN

This was a single-centre retrospective study of 393 SSTs measuring 0, 30 and 60 min cortisol levels after administration of 250 µg of synacthen.

PATIENTS AND METHODS

All the SSTs for patients suspected of primary or secondary AI between April 2016 and October 2018 were included in this study. The tests were performed as per our hospital protocol. A post-adrenocorticotropic hormone (ACTH) cortisol response of 420 nmol/L at any time point was considered adequate to rule out AI. The data were analysed to ascertain the proportion of patients who achieved this level at 30 and/or 60 min.

RESULTS

A total of 393 SST results were included in this study. Patients were divided into two groups depending on whether (group A) or not (group B) they were on steroids. Overall, a total of 313 (79.6%) subjects achieved cortisol level of ≥420 nmol/L at 30 and 60 min while 19 (4.8%) had late response (ie, insufficient 30 min cortisol levels, rising to ≥420 nmol/L at 60 min). Another 61 subjects (15.5%) showed insufficient response at both 30 and 60 min (ie, failed to achieved level of ≥420 nmol/L). Importantly, there was no patient in either group who had adequate response at 30 min and then failed at 60 min. Patients in group A were more likely to have inadequate response at both 30 and 60 min while patients in group B were more likely to have normal response at both time points.

CONCLUSIONS

Our results suggest that about 5% of people undergoing SST may be inappropriately diagnosed as having AI (and subjected to long-term unnecessary steroid treatment) if the 60 min sample is not maintained. We suggest that 30 min sample does not add any additional diagnostic utility and can be omitted thus simplifying SST even further and saving on cost and resources. We propose that single measurement after 60 min of administration of synthetic ACTH is a sufficient screening test for AI.

Residual endogenous corticosteroid production in patients with adrenal insufficiency

OBJECTIVE

This study aimed at comparing precursors of endogenous corticosteroid production in patients with primary adrenal insufficiency and in secondary adrenal insufficiency.

DESIGN

Twenty patients with primary adrenal insufficiency and matched controls and 19 patients with secondary adrenal insufficiency participated in this ancillary analysis of two different studies.

PATIENTS AND MEASUREMENTS

Patients with primary adrenal insufficiency were on stable hydrocortisone and fludrocortisone therapy. Patients with secondary adrenal insufficiency received two different doses of hydrocortisone in a randomized crossover study. Main outcome measures were concentrations of precursors of cortisol and aldosterone measured by LC-MS/MS RESULTS: Compared to controls, progressively lower concentrations of the glucocorticoid precursors 11-deoxycortisol, 11-deoxycorticosterone and corticosterone concentrations were found in patients with secondary adrenal insufficiency on lower hydrocortisone dose, secondary adrenal insufficiency on higher hydrocortisone dose and primary adrenal insufficiency, respectively. Half of the primary adrenal insufficient patients showed evidence of residual endogenous cortisol or aldosterone synthesis, as determined by quantifiable 11-deoxycortisol, 11-deoxycorticosterone and corticosterone conce ntrations. In secondary adrenal insufficient patients with higher endogenous cortisol production, as indicated by 11-deoxycortisol concentrations above the median, no increased cortisol exposure was observed both by plasma pharmacokinetic parameters and 24-hour free cortisol excretion in urine.

CONCLUSIONS

Adrenal corticosteroid production is likely to continue during treatment in a considerable percentage of patients with both primary and secondary adrenal insufficiency. In patients with secondary adrenal insufficiency, this synthesis appears to be sensitive to the dose of hydrocortisone. However, the residual corticosteroid concentrations were quantitatively low and its clinical significance remains therefore to be determined.

Non-functioning pituitary adenomas: indications for pituitary surgery and post-surgical management

PURPOSE

Non-functioning pituitary adenomas (NFPAs) are associated with impaired well-being, increased comorbidities, and reduced long-term survival. Data on optimal management of NFPAs around surgical treatment are scarce, and postoperative treatment and follow-up strategies have not been evaluated in prospective trials. Here, we review the preoperative, perioperative, and early postoperative management of patients with NFPAs.

METHODS

We searched Medline and the Cochrane Library for articles published in English with the following items "Pituitary neoplasms AND Surgery" and "Surgery AND Hypopituitarism". Studies containing detailed analyses of the management of NFPAs in adult patients, including pituitary surgery, endocrine care, imaging, ophthalmologic assessment and long-term outcome were reviewed.

RESULTS

Treatment options for NFPAs include active surveillance, surgical resection, and radiotherapy. Pituitary surgery is currently recommended as first-line treatment in patients with visual impairment due to adenomas compressing the optic nerves or chiasma. Radiotherapy is reserved for large tumor remnants or tumor recurrence following one or more surgical attempts. There is no consensus of optimal pre-, peri-, and postoperative management such as timing, frequency, and duration of endocrine, radiologic, and ophthalmologic assessments as well as management of smaller tumor remnants or tumor recurrence.

CONCLUSIONS

In clinical practice, there is a great variation in the treatment and follow-up of patients with NFPAs. We have, based on available data, suggested an optimal management strategy for patients with NFPAs in relation to pituitary surgery. Prospective trials oriented at drawing up strategies for the management of NFPAs are needed.

Early Basal Cortisol Level as a Predictor of Hypothalamic-Pituitary-Adrenal (HPA) Axis Function After Pituitary Tumor Surgery

PURPOSE

The purpose of this study was to evaluate the clinical relevance of the early postoperative basal cortisol level in assessing the postoperative hypothalamic-pituitary-adrenal (HPA) axis function after pituitary tumor surgery.

METHODS

We performed a prospective observational study that enrolled 83 patients operated for pituitary adenoma or other sellar lesions at the University Hospital Center Zagreb between December 2013 and April 2017 (44 nonfunctioning pituitary adenomas, 28 somatotropinomas, 5 craniopharyngiomas, 2 prolactinomas resistant to medical therapy and 4 other lesions - Rathke's cleft cyst, arachnoid cyst, chondroma and gangliocytoma). Exclusion criteria were Cushing's disease, chronic therapy with glucocorticoids prior to surgery and preoperative adrenal insufficiency. Early postoperative basal cortisol levels (measured on the second postoperative day) and the Synacthen stimulation test (performed 3 months after the surgery with the peak cortisol level of>500 nmol/L considered as a normal response) were analyzed to assess HPA axis function during follow-up.

RESULTS

ROC analysis showed a cut-off of the basal cortisol level of ≥300 nmol/L measured on the second postoperative day to predict normal postoperative HPA axis function with the sensitivity of 92.31%, specificity of 87.14% and positive predictive value of 57.14%.

CONCLUSION

The basal cortisol level on the second postoperative day is a valuable tool to predict integrity of the HPA axis after pituitary tumor surgery. Our data suggest that the cortisol level of ≥300 nmol/L accurately predicts adrenal sufficiency and that in these patients glucocorticoid therapy can be withdrawn.

Clinical utility of routine postoperative morning cortisol monitoring in detecting new hypothalamic-pituitary-adrenal axis insufficiency following endoscopic transsphenoidal surgery for sellar lesions

OBJECTIVE

Hypothalamic-pituitary-adrenal (HPA) axis dysfunction is a well-documented complication of transsphenoidal craniotomy (TSC) for sellar lesions. The authors aimed to assess their multidisciplinary approach to the diagnosis and treatment of postoperative hypocortisolemia utilizing conservative screening methods.

METHODS

The authors performed a retrospective review of 257 patients who underwent TSC for pituitary adenoma (PA) or Rathke cleft cyst (RCC) at the University of Southern California between 2012 and 2017. Patients with preoperative adrenal insufficiency, Cushing's disease, or < 3 months of postoperative follow-up were excluded. Patient demographics, pathology, tumor characteristics, and complications were recorded. Postoperative day 1 (POD1) morning serum cortisol was assessed in all patients. Hypocortisolemia on POD1 (serum cortisol < 5 μg/dl) prompted a 7 am cortisol level measurement on POD 2 (POD2). Clinical signs and symptoms of hypocortisolemia were consistently monitored. After two serum cortisol levels < 5 μg/dl, or one serum level < 5 μg/dl plus a high clinical suspicion for HPA dysfunction, high-risk patients received glucocorticoid supplementation.

RESULTS

Data on 165 patients were included in the analysis; there were 101 women (61.2%) and 64 men (38.7%). Preoperative diagnoses included nonfunctional adenoma (n = 97, 58.7%), growth hormone-secreting adenoma (n = 37, 22.4%), RCC (n = 18, 10.9%), prolactinoma (n = 8, 4.8%), and other (n = 5, 3.0%). One hundred thirty-eight patients (63.0%) had either suprasellar extension or cavernous sinus invasion. POD1 hypocortisolemia was diagnosed in 8 patients (4.8%). Of these patients, 2 (1.2%) were clinically asymptomatic and had normalized POD2 cortisol levels. Six patients (3.6%) had clinical symptoms and POD2 cortisol levels confirming HPA axis deficiency. Of these 6 patients treated with early glucocorticoid replacement, 2 patients recovered HPA axis function during follow-up, making the incidence of new, permanent HPA axis deficiency 2.5%.

CONCLUSIONS

In the authors' institutional review, all patients warranting postoperative glucocorticoid replacement had both complicated surgical courses and associated clinical symptoms of hypocortisolemia. The authors' algorithm of withholding steroids until patients demonstrate clear evidence of postoperative hypocortisolemia is safe and clinically efficacious. Their data further suggest that routine postoperative cortisol screening may not be necessary following an uncomplicated operative resection, with gland preservation and the absence of clinical symptoms indicative of HPA dysfunction.

Intraoperative low field MRI in transsphenoidal pituitary surgery

BACKGROUND

Intraoperative low field MRI (iMRI, 0.15 T) during transsphenoidal surgery on pituitary adenomas (PAs) may significantly improve tumor removal. However, extensive surgery can lead to pituitary hormone deficiency. Furthermore, introduction of iMRI will prolong duration of surgery, which may elevate risk of postoperative infections.

METHODS

Overall, 180 transsphenoidal surgeries for PAs from 2007 to 2015 were included. IMRI was available from 2011 to 2015, during this period 67/78 (86%) surgeries were with iMRI (iMRI, n = 67). A total of 113 surgeries were performed without iMRI (controls). All surgical procedures were performed by microscopic technique. Tumor size, hormonal status and vision were assessed before surgery and 3-5 months postoperatively.

RESULTS

Gross total resection (GTR), mean tumor remnant volume and ∆-volumes were comparable between iMRI and controls: 15% (10/66) vs 23% (26/109) (P = 0.17), 2.97 cm³ (0.9-5) vs 2.1 cm³ (1.6-2.6) (P = 0.3) and 4.5 cm³ (3.6-5.5) vs 5.1 cm³ (4.2-6) (P = 0.4), respectively. Duration of surgery was significantly longer during iMRI vs controls: 126 min (117-135) vs 98 min (92-103) (P < 0.001). New pituitary-adrenal deficiency in iMRI vs controls was seen in 35% (17/48) and 35% (23/66) of surgeries, respectively (P = 0.95). New thyroid deficiency was found in 33% (13/29) and 41% (28/69) and visual field deficiencies improved in 44% (19/43) and 38% (23/60) in iMRI vs controls, respectively (P > 0.1).

CONCLUSION

Tumor remnant after pituitary surgery was not significantly reduced using intraoperative low field MRI. Duration of surgery was increased in iMRI, but was not associated with increased infection rate. Pituitary hormonal function and vision were comparable between iMRI and controls.

Prospective evaluation of a week one overnight metyrapone test with subsequent dynamic assessments of hypothalamic-pituitary-adrenal axis function after pituitary surgery

OBJECTIVE

To determine whether an overnight metyrapone test (OMT) within the first week postpituitary surgery can definitively assess the hypothalamic-pituitary-adrenal (HPA) axis, compared with subsequent dynamic tests and glucocorticoid requirement at 6 months.

DESIGN

Prospective study measuring morning cortisol levels on days 3 and 4 post-operatively, OMT day 5-7 and week 6, week 6 250 μg short Synacthen test (SST) and week 7 insulin tolerance test (ITT).

PATIENTS AND MEASUREMENTS

Forty participants who underwent pituitary surgery at a single centre (Cushing's disease excluded) were followed for at least 6 months. 46% had pre-operative adrenal insufficiency.

PRIMARY OUTCOME

week 1 OMT compared to glucocorticoid requirement at 6 months.

SECONDARY OUTCOMES

the performance of ITT as a "definitive" test and all tests compared to glucocorticoid requirement at 6 months.

RESULTS

Week 1 OMT showed concordance with ITT at week 7 of 78% and glucocorticoid requirement at 6 months of 81% respectively which was not significantly different from post-operative morning cortisol levels; 37% of participants with an abnormal OMT on day 6 had a normal OMT at week 6. All HPA axis tests showed similar concordance with glucocorticoid requirement at 6 months of 80%-85%.

CONCLUSIONS

Overnight metyrapone test within the first week after pituitary surgery was no better than an early morning cortisol level at predicting glucocorticoid requirement at 6 months. OMT at week 6 demonstrated recovery of HPA axis in a substantial proportion of participants who failed earlier assessments; thus, definitive testing should be delayed until 6 weeks post-operatively.

Measuring cortisol in serum, urine and saliva - are our assays good enough?

Cortisol is a steroid hormone produced in response to stress. It is essential for maintaining health and wellbeing and leads to significant morbidity when deficient or present in excess. It is lipophilic and is transported bound to cortisol-binding globulin (CBG) and albumin; a small fraction (∼10%) of total serum cortisol is unbound and biologically active. Serum cortisol assays measure total cortisol and their results can be misleading in patients with altered serum protein concentrations. Automated immunoassays are used to measure cortisol but lack specificity and show significant inter-assay differences. Liquid chromatography - tandem mass spectrometry (LC-MS/MS) offers improved specificity and sensitivity; however, cortisol cut-offs used in the short Synacthen and Dexamethasone suppression tests are yet to be validated for these assays. Urine free cortisol is used to screen for Cushing's syndrome. Unbound cortisol is excreted unchanged in the urine and 24-h urine free cortisol correlates well with mean serum-free cortisol in conditions of cortisol excess. Urine free cortisol is measured predominantly by immunoassay or LC-MS/MS. Salivary cortisol also reflects changes in unbound serum cortisol and offers a reliable alternative to measuring free cortisol in serum. LC-MS/MS is the method of choice for measuring salivary cortisol; however, its use is limited by the lack of a single, validated reference range and poorly standardized assays. This review examines the methods available for measuring cortisol in serum, urine and saliva, explores cortisol in disease and considers the difficulties of measuring cortisol in acutely unwell patients and in neonates.

How should we interrogate the hypothalamic-pituitary-adrenal axis in patients with suspected hypopituitarism?

Hypopituitarism is deficiency of one or more pituitary hormones, of which adrenocorticotrophic hormone (ACTH) deficiency is the most serious and potentially life-threatening. It may occur in isolation or, more commonly as part of more widespread pituitary failure. Diagnosis requires demonstration of subnormal cortisol rise in response to stimulation with hypoglycemia, glucagon, ACTH(1-24) or in the setting of acute illness. The choice of diagnostic test should be individualised for the patient and clinical scenario. A random cortisol and ACTH level may be adequate in making a diagnosis in an acutely ill patient with a suspected adrenal crisis e.g. pituitary apoplexy. Often however, dynamic assessment of cortisol reserve is needed. The cortisol response is both stimulus and assay- dependent and normative values should be derived locally. Results must be interpreted within clinical context and with understanding of potential pitfalls of the test used.

Isolated Adrenocorticotropic Hormone or Thyrotropin Deficiency Following Mild Traumatic Brain Injury: Three Cases with Long-Term Follow-Up

Few studies have examined the clinical features and long-term outcomes of isolated pituitary hormone deficiencies after traumatic brain injury (TBI). Such deficiencies typically present at time intervals after TBI, especially after mild injuries such as concussions, which makes their diagnosis difficult without careful history taking. It is necessary to improve diagnosis and prevent life threatening or morbid conditions such as those that may occur in deficiencies of adrenocorticotropic hormone (ACTH) or thyroid-stimulating hormone (as known as thyrotropin, TSH), the two most important pituitary hormones in hypopituitarism treatment. Here, we report two cases of isolated ACTH deficiency and one case of isolated TSH deficiency. These patients presented at different time points after concussion and underwent long-term follow-ups.

Diagnostic Accuracy of Perioperative Measurement of Basal Anterior Pituitary and Target Gland Hormones in Predicting Adrenal Insufficiency After Pituitary Surgery

The insulin tolerance test (ITT) is the gold standard for diagnosing adrenal insufficiency (AI) after pituitary surgery. The ITT is unpleasant for patients, requires close medical supervision and is contraindicated in several comorbidities. The aim of this study was to analyze whether tumor size, remission rate, preoperative, and early postoperative baseline hormone concentrations could serve as predictors of AI in order to increase the diagnostic accuracy of morning serum cortisol. This prospective study enrolled 70 consecutive patients with newly diagnosed pituitary adenomas. Thirty-seven patients had nonfunctioning pituitary adenomas (NPA), 28 had prolactinomas and 5 had somatotropinomas. Thyroxin (T4), thyrotropin (TSH), prolactin, follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and insulin-like growth factor 1 (IGF-I) were measured preoperatively and on the sixth postoperative day. Serum morning cortisol was measured on the third postoperative day (CORT3) as well as the sixth postoperative day (CORT6). Tumor mass was measured preoperatively and remission was assessed 3 months after surgery. An ITT was performed 3 to 6 months postoperatively. Remission was achieved in 48% of patients and AI occurred in 51%. Remission rates and tumor type were not associated with AI. CORT3 had the best predictive value for AI (area under the curve (AUC) 0.868, sensitivity 82.4%, specificity 83.3%). Tumor size, preoperative T4, postoperative T4, and TSH were also associated with AI in a multivariate regression model. A combination of all preoperative and postoperative variables (excluding serum cortisol) had a sensitivity of 75.0% and specificity of 77.8%. The predictive power of CORT3 substantially improved by adding those variables into the model (AUC 0.921, sensitivity 94.1%, specificity 78.3%, PPV 81.9%, NPV of 92.7%). In a subgroup analysis that included only female patients with NPA, LH had exactly the same predictive value as CORT3. The addition of baseline LH to CORT3, increased sensitivity to 100.0%, specificity to 88.9%, PPV to 90.4%, and NPV to 100.0%. Besides CORT3, tumor size, thyroid hormones, and gonadotropins can serve as predictors of AI. LH in postmenopausal female patients with NPA has similar diagnostic accuracy as CORT3. Further studies are needed in order to validate the scoring system proposed by this study.

Is peri-operative steroid replacement therapy necessary for the pituitary adenomas treated with surgery? A systematic review and meta analysis

Background

Patients with pituitary adenomas usually receive “stress dose” steroids in the peri-operative peroids. Though randomized controlled trials(RCT) have not been performed to assess the necessity of steroid coverage, there are several studies that explained the changes of adrenal function during peri-operative peroids. The aim of the present study is to investigate whether it is necessary to employ conventional peri-operative glucocorticoid replacement therapy to all the patients undergoing surgery.

Methods

We searched studies addressing peri-operative steroids coverage for pituitary adenomas in the Web of Science, Medline and the Cochrane Library. Then we extracted studies about peri-operative morning serum cortisol(MSC) levels, morbidity of early postoperative adrenal insufficiency, postoperative diabetes insipidus, relationships between MSC levels and adrenal integrity. We used RevMan Software to combine the results for meta-analysis. We used fixed-effects models for there was no significant heterogeneity existed.

Findings

There are 18 studies from 11 countries published between 1987 and 2013 including 1224 patients. The postoperative serum cortisol levels were significantly increased compared with the preoperative one in hypothalamic-pituitary-adrenal axis(HPAA) functions preserved patients(P<0.00001). The morbidity of early postoperative adrenal insufficiency ranged from 0.96% to 12.90%, with the overall morbidity of 5.55%(41/739). There was no significant differences of early postoperative diabetes insipidus between no supplementation patients and in supplementation patients(P=0.82). Conversely, there may be some disadvantages of high levels of cortisols such as high incidence of osteopenia and bone derangement and even the increased mortality rate. The patients with MSC levels of less than 60 nmol/l at 3 days after operation is considered as adrenal insufficient and more than 270 nmol/l as adrenal sufficient. To patients with MSC levels of 60–270 nmol/l, we need more clinical data to establish further cortisol supplementation criteria.

Prediction of adrenocortical insufficiency after pituitary adenoma surgery using postoperative basal cortisol levels

Our aim was to analyze the correlation of early postoperative cortisol levels in patients after transsphenoidal pituitary adenoma surgery compared to the standard dose ACTH test and Insulin tolerance test (ITT) several months later. We retrospectively reviewed data from 94 patients operated for pituitary adenoma in years 2009-2012. The comparison of day 7 (median) postoperative basal cortisol levels and 3.6 months (median) after pituitary adenoma surgery stimulation test - standard dose 250 microg 1-24ACTH test in 83 patients or ITT in 11 patients were performed. All 16 patients with early postoperative cortisol levels >500 nmol/l proved a sufficient response in the stimulation tests. At basal cortisol levels of 370-500 nmol/l the sufficient response was found in 96 % (27/28) of patients. In the postoperative basal cortisol levels 200-370 nmol/l we found a preserved corticotroph axis later on in 88 % (28/32) of cases. Patients with basal cortisol levels 100-200 nmol/l had a maintained corticotroph axis function in 8/11 cases - 73 %. All patients with an early postoperative basal cortisol level above 500 nmol/l proved in the stimulation tests a preserved corticotroph axis function. The interval 370-500 nmol/l showed a minimal risk of postoperative adrenal insufficiency.

Method-specific serum cortisol responses to the adrenocorticotrophin test: comparison of gas chromatography-mass spectrometry and five automated immunoassays

OBJECTIVE

The serum cortisol response to the adrenocorticotrophin (ACTH) test is known to vary significantly by assay, but lower reference limits (LRL) for this response have not been established by the reference gas chromatography-mass spectrometry (GC-MS) method or modern immunoassays. We aimed to compare the normal cortisol response to ACTH stimulation using GC-MS with five widely used immunoassays.

DESIGN, PATIENTS AND MEASUREMENTS

An ACTH test (250 μg iv ACTH1-24 ) was undertaken in 165 healthy volunteers (age, 20-66 years; 105 women, 24 of whom were taking an oestrogen-containing oral contraceptive pill [OCP]). Serum cortisol was measured using GC-MS, Advia Centaur (Siemens), Architect (Abbott), Modular Analytics E170 (Roche), Immulite 2000 (Siemens) and Access (Beckman) automated immunoassays. The estimated LRL for the 30 min cortisol response to ACTH was derived from the 2·5th percentile of log-transformed concentrations.

RESULTS

The GC-MS-measured cortisol response was normally distributed in males but not females, with no significant gender difference in baseline or post-ACTH cortisol concentration. Immunoassays were positively biased relative to GC-MS, except in samples from women on the OCP, who showed a consistent negative bias. The LRL for cortisol was method-specific [GC-MS: 420 nm; Architect: 430 nm; Centaur: 446 nm; Access 459 nm; Immulite (2000) 474 nm] and, for the E170, also gender-specific (female: 524 nm; male 574 nm). A separate LRL is necessary for women on the OCP.

CONCLUSIONS

Normal cortisol responses to the ACTH test are influenced significantly by assay and oestrogen treatment. We recommend the use of separate reference limits in premenopausal women on the OCP and warn users that cortisol measurements in this subgroup are subject to assay interference.

Selective use of peri-operative steroids in pituitary tumor surgery: escape from dogma

OBJECTIVE

Traditional neurosurgical practice calls for administration of peri-operative stress-dose steroids for sellar-suprasellar masses undergoing operative treatment. This practice is considered critical to prevent peri-operative complications associated with hypoadrenalism, such as hypotension and circulatory collapse. However, stress-dose steroids complicate the management of these patients. It has been our routine practice to use stress steroids during surgery only if the patient has clinical or biochemical evidence of hypocortisolism pre-operatively. We wanted to be certain that this practice was safe.

METHODS

We present our retrospective analysis from a consecutive series of 114 operations in 109 patients with sellar and/or suprasellar tumors, the majority of whom were managed without empirical stress-dose steroid coverage. Only patients who were hypoadrenal pre-operatively or who had suffered apoplexy were given stress-dose coverage during surgery. We screened for biochemical evidence of hypoadrenalism as a result of surgery by measuring immediate post-operative AM serum cortisol levels.

RESULTS

There were no adverse events related to the selective use of cortisol replacement in this patient population.

CONCLUSION

Our experience demonstrates that selective use of corticosteroid replacement is safe; it simplifies the management of the patients, and has advantages over empiric "dogmatic" steroid coverage.

Recovery of the hypothalamic-pituitary-adrenal axis in children and adolescents after surgical cure of Cushing's disease

CONTEXT

Recovery of the hypothalamic-pituitary-adrenal axis (HPAA) after transsphenoidal surgery (TSS) for Cushing's disease (CD) in children has not been adequately studied.

OBJECTIVE

Our objective was to assess time to recovery of the HPAA after TSS in children with CD.

DESIGN AND SETTING

This was a case series at the National Institutes of Health Clinical Center.

PATIENTS

Fifty-seven patients with CD (6-18 yr, mean 13.0 ± 3.1 yr) given a standard regimen of glucocorticoid tapering after TSS were studied out of a total of 73 recruited.

INTERVENTIONS

ACTH (250 μg) stimulation tests were administered at approximately 6-month intervals for up to 36 months. Age, sex, pubertal status, body mass index, length of disease, midnight cortisol, and urinary free cortisol at diagnosis were analyzed for effects on recovery.

MAIN OUTCOME MEASURE

The main outcome measure was complete recovery of the HPAA as defined by a cortisol level of at least 18 μg/dl in response to 250 μg ACTH.

RESULTS

Full recovery was reached by 43 (75.4%) of 57 patients, with 29 of the 43 (67.4%) and 41 of the 43 (95.3%) recovering by 12 and 18 months, respectively. The overall mean time to recovery was 12.6 ± 3.3 months. Kaplan-Meier survivor function estimated a 50% chance of recovering by 12 months after TSS and 75% chance of recovering within 14 months. By receiver operating characteristic curve assessment, the cutoff of at least 10-11 μg/dl of cortisol as the peak of ACTH stimulation testing at 6 months after TSS yielded the highest sensitivity (70-80%) and specificity (64-73%) to predict full recovery of the HPAA at 12 months. Two of the four patients that recovered fully within 6 months had recurrent CD.

CONCLUSIONS

Although this is not a randomized study, we present our standardized tapering regimen for glucocorticoid replacement after TSS that led to recovery of the HPAA in most patients within the first postoperative year. Multiple factors may affect this process, but an early recovery may indicate disease recurrence.

Safety and cost effectiveness of early discharge following microscopic trans-sphenoidal resection of pituitary lesions

Background:

Inpatient hospitalization following trans-sphenoidal resection of a pituitary neoplasm has traditionally involved a hospital stay of 2 days or more. It has been the policy of the senior pituitary neurosurgeon (GSA) since February 2008 to allow discharge home on postoperative day (POD) 1 if thirst mechanism is intact and the patient is tolerating oral hydration. The goal of this study was to evaluate the safety and cost-effectiveness of this practice.

Methods:

We reviewed the charts of 30 patients, designated the early discharge group, who consecutively underwent microscopic trans-sphenoidal resection from February 2008 to December 2009. We then reviewed the charts of 30 patients, designated the standard discharge group, who consecutively underwent trans-sphenoidal resection from May 2007 to February 2008 before discharge home on POD1 was considered an appropriate option. Safety and cost-effectiveness of the two patient groups were retrospectively evaluated.

Results

Patients in the early discharge group went home, on average, on POD 1.3. Following exclusion of two outliers, the average date of discharge of patients in the standard discharge group was POD 2.2. The policy of early discharge saved an average of $1,949 per patient-approximately 4% the total cost of the procedure. Trends toward decreased costs did not reach statistical significance. While no patient suffered any measurable morbidity as a result of early discharge home, 1 in 3 patients in the early discharge group required unscheduled postoperative re-evaluation-a figure significantly higher than the standard discharge group.

Conclusions:

At a dedicated pituitary center with the resources to closely monitor outpatient endocrinological and postsurgical issues, early discharge home following trans-sphenoidal surgery is a safe option that is associated with an increase in the number of unscheduled postoperative visits and a trend toward lower costs.

Reliability of hypothalamic-pituitary-adrenal axis assessment methods for use in population-based studies

Population-based studies have been hampered in exploring hypothalamic-pituitary-adrenal axis (HPA) activity as a potential explanatory link between stress-related and metabolic disorders due to their lack of incorporation of reliable measures of chronic cortisol exposure. The purpose of this review is to summarize current literature on the reliability of HPA axis measures and to discuss the feasibility of performing them in population-based studies. We identified articles through PubMed using search terms related to cortisol, HPA axis, adrenal imaging, and reliability. The diurnal salivary cortisol curve (generated from multiple salivary samples from awakening to midnight) and 11 p.m. salivary cortisol had the highest between-visit reliabilities (r = 0.63-0.84 and 0.78, respectively). The cortisol awakening response and dexamethasone-suppressed cortisol had the next highest between-visit reliabilities (r = 0.33-0.67 and 0.42-0.66, respectively). Based on our own data, the inter-reader reliability (r(s)) of adrenal gland volume from non-contrast CT was 0.67-0.71 for the left and 0.47-0.70 for the right adrenal glands. While a single 8 a.m. salivary cortisol is one of the easiest measures to perform, it had the lowest between-visit reliability (R = 0.18-0.47). Based on the current literature, use of sampling multiple salivary cortisol measures across the diurnal curve (with awakening cortisol), dexamethasone-suppressed cortisol, and adrenal gland volume are measures of HPA axis tone with similar between-visit reliabilities which likely reflect chronic cortisol burden and are feasible to perform in population-based studies.

Can basal cortisol measurement be an alternative to the insulin tolerance test in the assessment of the hypothalamic-pituitary-adrenal axis before and after pituitary surgery?

BACKGROUND

The aims of this study were to evaluate the validity of preoperative basal serum cortisol levels measured in predicting preoperative adrenal insufficiency and also the validity of basal serum cortisol levels and early postoperative insulin tolerance test (ITT) in predicting postoperative adrenal insufficiency.

METHODS

The study was prospectively designed and included 64 patients who underwent pituitary surgery for conditions other than Cushing's disease. An ITT was performed preoperatively, on the 6th postoperative day and at the 1st postoperative month. Basal serum cortisol levels were measured on the 2nd, 3rd, 4th, 5th, and 6th postoperative days.

RESULTS

Patients with a preoperative basal cortisol level of <165 nmol/l (6 microg/dl) showed insufficient cortisol response and those with levels higher than 500 nmol/l (18 microg/dl) had sufficient cortisol response to the preoperative ITT. The positive predictive value of the ITT performed on the 6th postoperative day was 69.7%, and the negative predictive value in predicting adrenal insufficiency at the 1st postoperative month was 58%. Patients were considered to have an insufficient cortisol response to ITT at the 1st postoperative month if their basal cortisol levels were <193 nmol/l (7 microg/dl) or 220 nmol/l (8 microg/dl) or 193 nmol/l (7 microg/dl) or 165 nmol/l (6 microg/dl) or 83 nmol/l (3 microg/dl) on the 2nd-6th postoperative days respectively.

CONCLUSION

Serum basal cortisol levels may be used as the first-line test in the assessment of the hypothalamic-pituitary-adrenal axis both preoperatively and postoperatively. Dynamic testing should be limited to the patients with indeterminate basal cortisol levels.

The rational use of pituitary stimulation tests

BACKGROUND

Diseases of the pituitary gland can lead to the dysfunction of individual hormonal axes and to the corresponding clinical manifestations. The diagnostic assessment of pituitary function has not yet been standardized.

METHODS

The members of the Neuroendocrinology Section and the Pituitary Study Group of the German Society for Endocrinology (Deutsche Gesellschaft für Endokrinologie) prepared outlines of diagnostic methods for the evaluation of each of the pituitary hormonal axes. These outlines were discussed in open session in recent annual meetings of the Section and the Study Group.

RESULTS

For the evaluation of the thyrotropic axis, basal TSH and free T4 usually suffice. For the evaluation of the gonadotropic axis in men, the testosterone level should be measured; if the overall testosterone level is near normal, then calculating the free testosterone level may be additionally useful. In women, an intact menstrual cycle is sufficient proof of normal function. In the absence of regular menstruation, measurement of the basal estradiol and gonadotropin levels aids in the diagnosis of the disturbance. For the evaluation of the adrenocorticotropic axis, the basal cortisol level may be helpful; provocative testing is in many cases necessary for precise characterization. The evaluation of the somato-tropic axis requires provocative testing. Aside from the insulin tolerance test, the GHRH-arginine test has become well established. Reference ranges normed to the body mass index (BMI) are available.

CONCLUSION

The diagnostic evaluation of pituitary insufficiency should proceed in stepwise fashion, depending on the patient's clinical manifestations and underlying disease. For some pituitary axes, measurement of basal hormone levels suffices; for others, stimulation tests are required. In general, the performance of combined pituitary tests should be viewed with caution.

Fractionated stereotactic radiotherapy in patients with acromegaly: an interim single-centre audit

AIM

To evaluate the effect of fractionated stereotactic radiotherapy (FSRT) in acromegaly in a retrospective analysis.

PATIENTS AND METHODS

Thirty-four patients (17 females, median 43 years (range 30-74)) with acromegaly were treated with FSRT (conformal dynamic arcing, dose 54 Gy, 27-30 fractions) between January 1998 and April 2007. Of the 34 patients, 32 had undergone transsphenoidal adenotomy, and 28 were on medical therapy before FSRT. Patients on medical therapy continued this during and after the irradiation. The treatment was gradually decreased/withdrawn after careful assessment.

RESULTS

Magnetic resonance scanning of the pituitary gland 34 months (median, range 11-95) after irradiation showed stable or reduced volume of the remaining tumour tissue in 31 of 34 patients (91%). Seventeen patients (50%) were biochemically controlled (normalised nadir GH during oral glucose tolerance test and IGF1 <+2 S.D.) 30 months after FSRT (median, range 6-60), and ten of them had true biochemical remission (off medical therapy) 30 months after FSRT (median, range 12-69). Of 28 patients with one or more functioning pituitary axes before irradiation, 8 (29%) developed further deficit of one or two pituitary axes 48 months (median, range 6-102) after FSRT. Of 34 patients, 20 still required medical treatment for acromegaly at the end of this study, mainly those with a short follow-up period after irradiation.

CONCLUSION

The FSRT seems promising in terms of treatment of acromegaly. Longer follow-up is, however, needed to assess the overall efficacy and safety of FSRT for acromegaly.

National UK audit of the Short Synacthen® Test

We present the first national audit of the Short Synacthen Test (SST), identifying the clinical, analytical and interpretative procedures adopted by 89 laboratories.

Background

The SST has replaced the insulin stress test as the first-line test to assess adrenal insufficiency and has received considerable attention regarding its sensitivity and specificity. Concerns regarding this test include the bias of cortisol methods, cut-off values used, contraindications and the limitations of the test in diagnosing recent, mild secondary adrenal insufficiency. The audit took into consideration the protocols used by laboratories, the advice provided prior and after the SST and the analytical bias of the methods used.

Methods

A web-based questionnaire using Microsoft FrontPageTM was prepared to collect data from laboratories and provided drop-down lists and other form-field elements to capture additional comments. The resultant data were exported to Microsoft ExcelTM for data clean-up and analysis.

Results

The workloads were highly variable; however, most laboratories were in general agreement to the indications, contraindications, timing and reference ranges. In contrast, there was variability in the bias of the cortisol methods, which had not been translated to the cut-off values used by the majority of laboratories.

Conclusions

The audit has shown that though the preanalytical procedures were similar in most laboratories, there is a requirement to recognize the effect that method bias may have on the reference ranges and consequently on the diagnosis of adrenal insufficiency. There is a need to develop consensus guidelines, which can aid both clinicians and laboratories.

The diagnosis and investigation of adrenal insufficiency in adults

There is considerable variation in the methods used to diagnose and investigate adrenal insufficiency in clinical practice. These include a range of adrenocorticotropin (ACTH) stimulation and other dynamic testing protocols, serum cortisol cut-off values for diagnosis and tests used for differential diagnosis. With the introduction of modern cortisol and ACTH assays, the interpretation of tests used for diagnosis and differential diagnosis has become more complex and requires local validation. This review examines the basis of normal hypothalamic-pituitary-adrenal axis function and adrenal insufficiency states based upon an evidence base accumulated over the past four decades. The role of the laboratory in the differential diagnosis and interpretation based upon assay methodology is discussed. The accurate identification of patients who may benefit from corticosteroid replacement in special settings such as critical illness is challenging and will be explored.

Perioperative cortisol can predict hypothalamus-pituitary-adrenal status in clinically non-functioning pituitary adenomas

BACKGROUND

Peri-operative steroids are administered routinely to patients with pituitary adenoma undergoing transsphenoidal adenomectomy (TSA).

AIM

To evaluate hypothalamic-pituitary-adrenal (HPA) axis before and after programmed endoscopic TSA (E-TSA) in patients with clinically non-functioning pituitary macroadenoma (NFPA).

DESIGN

Open prospective.

SETTING

Tertiary referral hospitals.

PATIENTS

Seventy-two consecutive patients (20-87 yr, 37 males).

INTERVENTIONS

Adrenal steroid replacement therapy (ASRT) was given only in patients with hypocortisolism [08:00 h cortisol (F) <8 microg/dl].

MAIN OUTCOME MEASUREMENTS

After ETSA, achieving wide (>90%) selective resection of the adenoma in all, F and clinical picture were checked at day 2. The low-dose (1 microg) ACTH test (LDACTH) was performed at 6 weeks and repeated at 12 months.

RESULTS

Hypocortisolism was present pre-operatively in 14 patients (19.4%), persisted post-operatively in all but one, and was detected de novo at the post-operative day 2 control in 6 (10.3%). In all but one the post-operative day 2 basal F and peak F during LDACTH test were concordant. No patient whose F was > 8 microg/dl was treated with ASRT or developed symptoms of adrenal failure during the follow-up (1-11 yr, median 5).

CONCLUSIONS

HPA function is usually preserved in NFPA and is infrequently impaired after complete tumor removal by E-TSA. The 08:00 h. plasma cortisol evaluation before and 2 days after surgery, using as cut-off the value of 8 microg/dl, allows full evaluation of HPA status. Peri-operative steroid treatment should be given only in patients with hypocortisolism.

Diagnosis of secondary adrenal insufficiency in patients with hypothalamic-pituitary disease: comparison between serum and salivary cortisol during the high-dose short synacthen test

OBJECTIVE

Accurate assessment of adrenal function is essential in patients with hypothalamic-pituitary-adrenal (HPA) disease. The measurement of salivary cortisol (SaC) instead of serum cortisol (SeC) offers several advantages, such as the determination of the free hormone. We evaluated the diagnostic value of SeC and SaC both unstimulated and during a high-dose short synacthen test (HDT) in comparison to the insulin tolerance test (ITT).

DESIGN

Comparative study between 2005 and 2007.

METHODS

Fifty-five patients with HPA impairment and 21 healthy controls were enrolled. Samples were collected in the early morning and over 120 min during the HDT. Receiver operating characteristic analysis revealed individual thresholds for four HDT periods (0-30, 0-60, 0-90, and 0-120 min).

RESULTS

The ITT identified 30 subjects as adrenal insufficient. With respect to the four HDT periods, sensitivity and specificity were 67-79% and 71-88% for SeC, compared with 63-72% and 72-86% for SaC. If upper and lower thresholds (with specificities >95%) were applied, patients were diagnosed in 40-45% by SeC and in 25-31% by SaC. The combination of basal cortisol and HDT allowed a diagnosis in 47-49% (SeC) and in 42-45% (SaC) respectively.

CONCLUSION

We suggest the determination of basal SeC or SaC as first-line test. In comparison to the ITT, the HDT has only limited value in screening for alterations of the HPA axis. If the HDT is performed, sampling may be limited to 30 min post-synacthen, using either SeC or SaC. Due to the ease of collection and the independence of binding proteins, SaC may be preferable.

Long-term basal and dynamic evaluation of hypothalamic-pituitary-adrenal (HPA) axis in acromegalic patients

OBJECTIVE

Long-term effects of trans-naso-sphenoidal surgery (TNS) or long-acting somatostatin analogs (SSA) on the function of hypothalamic-pituitary-adrenal (HPA) axis have been poorly investigated. Aim of this study was to evaluate HPA axis integrity during the follow-up in patients with GH-secreting pituitary adenomas and preserved HPA function post-TNS or prior SSA.

DESIGN AND PATIENTS

This retrospective study investigated 36 acromegalic patients (16M and 20F, age: 47 +/- 13 years), 20 of whom cured by TNS and 16 controlled by SSA therapy (12 previously operated and 4 in primary medical therapy), before and after long-term follow-up (median: 72 months, range: 12-240). No patient previously underwent radiotherapy.

MEASUREMENTS

HPA function was studied by morning circulating cortisol and ACTH levels, 24-h urinary free cortisol (UFC) and cortisol response to low-dose short Synacthen test (LDSST, 1 microg) with a peak > 500 nmol/l as cut-off for normal function.

RESULTS

Serum basal cortisol, ACTH and UFC levels were in the normal range and did not significantly change over time. As far as the cortisol peak after LDSST is concerned, 12 patients (32%, 8 TNS and 4 SSA) developed biochemical hypoadrenalism. None of the patients in primary medical therapy showed cortisol peak < 500 nmol/l. No significant correlations between HPA axis deterioration and follow-up duration, serum GH/IGF-I levels, occurrence of other pituitary deficiencies, presence of secondary empty sella, changes in tumour or residual volume were observed.

CONCLUSIONS

The HPA axis function must be carefully monitored over the time by dynamic testing in all acromegalic patients, independently from the type of treatment.

Postoperative assessment of the patient after transsphenoidal pituitary surgery

While most transsphenoidal pituitary surgery is accomplished without complication, monitoring is required postoperatively for a set of disorders that are specific to this surgery. Postoperative assessments are tailored to the early and later postoperative periods. In the early period, which spans the first few weeks after surgery, both monitoring of anterior and posterior pituitary function and managing neurosurgical issues are the focus of care. Potential disruption of pituitary-adrenal function is covered with perioperative glucocorticoids. Various strategies exist for ensuring the integrity of this axis, but typically this is done by measuring a morning cortisol on the 2nd or 3rd postoperative days. Patients with levels <10 microg/l should continue therapy with reassessment in the later postoperative period. Monitoring for water imbalances, which are due to deficiency or excess of ADH (DI or SIADH, respectively), is accomplished by continuous accounting of fluid intake, urine output and specific gravities coupled with daily serum electrolyte measurements. DI is characterized by excess volumes of inappropriately dilute urine, which can lead to hypernatremia. Most patients maintain adequate fluid intake and euvolemia, but desmopressin therapy is required for some. SIADH, which peaks in incidence on 7th postoperative day, presents with hyponatremia that can be severe and symptomatic. Management consists of fluid restriction. Neurosurgical monitoring is primarily for disturbances in vision or neurological function, and although uncommon, for CSF leak and infections such as meningitis. In the later postoperative period, the adrenal, thyroid and gonadal axes are assessed. New persistent hypopituitarism is rare when transsphenoidal surgery is performed by an experienced surgeon. Various strategies are available for assessing each axis and for providing replacement therapy in patients with deficiencies. Long term monitoring with assessments of visual, neurological and pituitary function coupled with pituitary imaging is necessary for all patients who have undergone surgery, irrespective of the hormone status of their tumors.

[Pituitary and adrenal gland surgery]

Laparoscopic adrenalectomy and transsphenoidal pituitary surgery are currently established as the surgical procedures of choice with a low complication rate. Beyond potential surgical complications, one has to consider endocrine sequelae such as adrenal insufficiency and hypopituitarism. Without adequate endocrine treatment patients are prone to develop potentially lethal complications such as Addisonian crises or pituitary coma. Therefore, all patients should be seen by an endocrinologist before and after surgery. Patients with bilateral adrenalectomy require lifelong substitution of glucocorticoids and mineralocorticoids. Cushing's syndrome patients with unilateral adrenalectomy need temporary substitution. After pituitary surgery, all patients require functional assessment of their pituitary function, and, if necessary, adequate replacement therapy.

Anterior pituitary hormone replacement therapy--a clinical review

This clinical review summarizes current approaches to diagnosis and treatment of anterior pituitary hormone deficiency. The diagnostic value of endocrine function tests and replacement strategies for hydrocortisone, thyroxine, sex steroids, and growth hormone replacement are reviewed. Female androgen deficiency syndrome and the current role of DHEA and testosterone replacement in women are also discussed.