What Tests Help Determine if my Basal Rates are Adequate?
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You will need multiple lab tests to check your rates. These tests should at least include serial cortisol draws, saliva cortisol testing (or free serum cortisol), and potentially a 24 hour urinary cortisol. Follow up lab testing is one of the most important things you can do to ensure your success with the cortisol pump and achieve the full benefit of this delivery method. You will need an experienced medical professional, not only to order these tests, but to interpret the results. Data is useless to someone who doesn’t understand what it means.
Follow up lab testing is one of the most important things you can do to ensure your success with the cortisol pump.
Follow up testing may need to be conducted every few weeks at first when basal rates need the most adjustments. Once the rates seem right and the pumper is stable, testing may only be required every 6 months. If all is well, the testing may be decreased to once per year (Bryan, et al 2009).
Below are some common follow up testing methods.
Serial Cortisol Draws
The most essential of follow up tests is cortisol testing. This entails testing blood cortisol levels a number of times in a 24 span. The preferred and most through method is hourly blood draws over the 24 hour period. (Hindmarsh, Geertsma 2017 p 370) For this method, the pump is programmed and started. The 24 hour profile can be performed as soon as 1-2 days after initiating pump therapy (Nella, et al 2016).
For hourly venous sampling, the pumper will need to be admitted and have an IV cannula placed. Blood draws can begin anytime in the 24 hour period as long as they are ended at that same hour 24 hours later. Nurses must be made aware that blood draws must be taken exactly one hour apart, even during shift change. Timing errors will reduce the accuracy of the profile to some degree.
The pumper must not bolus, modify their basal program, or take any oral glucocorticoids during this test or it will invalidate the result. Mineralcorticoid replacement should continue as normal. This is strictly to test the basal that has been programmed. If the pumper is experiencing low cortisol symptoms or symptoms of adrenal crisis, this obviously takes precedence over the test. Emergency situations should be treated accordingly.
24 hour, hourly testing will provide the most data, which should mean the basal programmed is adjusted more quickly and accurately than other methods involving fewer blood draws.
There are drawbacks to 24 hour, hourly testing. Having blood drawn hourly can be tough for the pumper. This means very little or no sleep over the 24 hour period. The blood draws can cause some minor trauma to the vein, even with an IV placed. Pumpers should take extra care to be well hydrated during this testing period.
There is also potential for lab mix ups if the nursing staff isn’t properly briefed. Any late draws or mix ups of samples will diminish the accuracy of the profile. Hospital admission is involved, usually insurance companies will cover this as “observation.” If hospital admittance is not feasible for the patient, there are alternatives.
Hourly blood draws are the ideal testing method, but if that cannot be done, the medical provider should aim for as many serial cortisol draws as possible. More draws means more data to work with. Alternatively, tests can be ordered as “random” cortisol draws. These can the performed at anytime of day.
If there is a 24 hour lab available, such as a hospital outpatient lab, then testing can still be done at night and early morning hours. Options might be every 4 hours for a total of 6 tests (Sonnet, et al 2011), if there is not a 24 hour lab in the area the pumper can travel, chain lab locations can be used for cortisol testing as well.
The pumper should have multiple labs drawn during the lab’s available hours. After hours adjustments can be made based on salivary cortisol or completely by salivary cortisol if blood testing cannot be performed at all (Løvås, Husebye 2007).
Adjustments should be made based on ideal levels in normal people with an 8 am level around 20 mcg/dL (550 nmol/L) and a bedtime level around 2 mcg/dL (55 nmol/L), afternoon levels should be gradually decreasing in between these two measurements. Cortisol results should be ideal rather than simply “normal,” and attention should be payed to the pumper’s symptoms and quality of life (Broussard, et al 2015).
Saliva Cortisol (Free Cortisol) Tests
Salivary testing records free cortisol. Blood testing is most often total cortisol, although free cortisol can also be ordered and tested via blood draw. Ideally, both total and free cortisol should be tested, and basal rates should be adjusted so that both values are in optimal ranges. Researchers use anywhere from 4 (Løvås, Husebye 2007), to 13 (Øksnes, et al 2014) saliva samples in a 24 hour period. These samples can be taken along with 8am cortisol (Øksnes, et al 2014) to provide additional data.
24 Hour Urinary Cortisol Tests
Blood and saliva cortisol testing are often accompanied by 24 hour urinary cortisol (Cardini, et al 2018). On its own, 24hr urinary cortisol does not provide much data about individual rates and which time blocks may need to be adjusted. What it does do is provide a bigger picture. While individual blood and saliva results could all be somewhere within lab ranges, 24 hour urinary cortisol will let you know if the total daily dosage is within range (its especially good for detecting a total dosage above range).
Other Tests
Other testing may be required depending on the individual’s diagnosis. Those with primary adrenal insufficiency should have normalized ACTH levels when the pump is properly programmed and adjusted (Bjornsdottir, et al 2015).
Individuals with Congenital Adrenal Hyperplasia will need 17OHP tested to ensure it is adequately suppressed (Hindmarsh, Geertsma 2017).
Find out more:
Where Can I Learn More about the Cortisol Pump?
Should I Use Powder Vials or Act-o-vials?
Sources
Bjornsdottir, S., Nystrom, T., Isaksson, M., Oksnes, M., Husebye, E., Lovas, K., … Bensing, S. (2013). Insulin sensitivity in patients with Addisons disease: a randomised cross-over trial comparing conventional glucocorticoid replacement therapy with continuous subcutaneous hydrocortisone infusion therapy. Endocrine Abstracts. doi: 10.1530/endoabs.32.p9
Broussard, Julia R., and Naim Mitre. “Successful Use of Continuous Subcutaneous Hydrocortisone Infusion after Bilateral Adrenalectomy Secondary to Bilateral Pheochromocytoma.” Journal of Pediatric Endocrinology and Metabolism, vol. 28, no. 7-8, Jan. 2015, doi:10.1515/jpem-2014-0473.
Bryan, S. M., Honour, J. W., & Hindmarsh, P. C. (2009). Appendix of: Management of Altered Hydrocortisone Pharmacokinetics in a Boy with Congenital Adrenal Hyperplasia Using a Continuous Subcutaneous Hydrocortisone Infusion. The Journal of Clinical Endocrinology & Metabolism, 94(9), 3477–3480. doi: 10.1210/jc.2009-0630
Cardini, F., Torlone, E., Bini, V., & Falorni, A. (2018). Continuous subcutaneous hydrocortisone infusion in a woman with secondary adrenal insufficiency. Endocrine, 63(2), 398–400. doi: 10.1007/s12020-018-1780-4
Hindmarsh, P. C., & Geertsma, K. (2017). Congenital adrenal hyperplasia: a comprehensive guide. London: Elsevier/Academic Press.
Løvås Kristian, & Husebye, E. S. (2007). Continuous subcutaneous hydrocortisone infusion in Addison’s disease. European Journal of Endocrinology, 157(1), 109–112. doi: 10.1530/eje-07-0052
Nella, A. A., Mallappa, A., Perritt, A. F., Gounden, V., Kumar, P., Sinaii, N., … Merke, D. P. (2016). A Phase 2 Study of Continuous Subcutaneous Hydrocortisone Infusion in Adults With Congenital Adrenal Hyperplasia. The Journal of Clinical Endocrinology & Metabolism, 101(12), 4690–4698. doi: 10.1210/jc.2016-1916
Øksnes, M., Björnsdottir, S., Isaksson, M., Methlie, P., Carlsen, S., Nilsen, R. M., … Løvås, K. (2014). Continuous Subcutaneous Hydrocortisone Infusion versus Oral Hydrocortisone Replacement for Treatment of Addisons Disease: A Randomized Clinical Trial. The Journal of Clinical Endocrinology & Metabolism, 99(5), 1665–1674. doi: 10.1210/jc.2013-4253
Sonnet, E., Roudaut, N., & Kerlan, V. (2011). Results of the Prolonged Use of Subcutaneous Continuous Infusion of Hydrocortisone in a Man with Congenital Adrenal Hyperplasia. ISRN Endocrinology, 2011, 1–4. doi: 10.5402/2011/219494