Exogenous Cushing’s Syndrome: Causes, Symptoms And Nursing Interventions

Primary and Secondary Causes of Cushing’s Syndrome

1.Exogenous Cushing’s syndrome is a condition caused by elevated levels of cortisol that results from excessive intake of glucocorticoids. Cushing’s syndrome is an endrocrinopathy as it results from inability of an endocrine gland to function properly. Cushing syndrome can be as a result of a primary cause and a secondary cause. The primary cause is independent of the ACTH hormone produced by the pituitary gland. The primary causes are related to over secretion of cortisol by the adrenal gland and include adrenal tumors (Sharma, Nieman & Feelders, 2015). On the other hand secondary causes of Cushing’s syndrome are ACTH dependent. The pituitary gland is also referred to as the master gland as it controls other glands within the body of which the adrenal gland is part of them.

ACTH is secreted by the pituitary gland and has its effect on the adrenal gland where it stimulates the release of cortisol. Increased secretion of ACTH can therefore cause abnormal secretion of cortisol by the adrenal gland hence Cushing’s syndrome. Exogenous Cushing’s syndrome results from excessive glucocorticoid hormone intake is ACTH independent (Morgan, Hassan-Smith & Lavery, 2016). As the term explains, an exogenous cause of a disease is any cause that comes from outside the body. Ms. Maureen’s case of exogenous Cushing’s syndrome was as a result of a high dose of corticosteroid medication that was prescribed for her rheumatoid arthritis. Prednisolone is a corticosteroid that is used to treat various medical conditions.

The incidence of Exogenous Cushing’s syndrome varies depending on the population beliefs and perception as far as corticosteroids are concerned. Patients suffering from medical conditions that are associated with corticosteroid intake such as rheumatoid arthritis and other inflammatory diseases like asthma, lupus urticaria and inflammatory bowel disease tend to suffer from the condition as compared to those who are don’t take such medications. According to Pivonello et al. (2016), frequency of the condition varies from one population to another depending on cultural and ethnic backgrounds. For example, there are a number of communities that don’t believe in taking corticosteroids due to their negative belief systems associated with such medication. The condition is associated with excessive intake of corticosteroids and this can be caused by exacerbation of conditions that require these types of medication. Ms. Maureen for example sought high doses of the corticosteroid prednisolone due to exacerbation of her rheumatic arthritis condition hence was predisposed to contracting the disease. 

Risk Factors Associated with Exogenous Cushing’s Syndrome

There are a number of risk factors associated with exogenous Cushing’s syndrome. The main risk factor is obviously excessive intake of glucocorticoids due to a current inflammatory medical condition. The medications of corticosteroids can either be oral doses or injectable medicines. As stated by Pappachan et al. (2017), the risk of contracting the condition is increased by overuse of these medications. Corticosteroids cause immune suppression. Such a disease has a lot of impact on the patient and the family as well. The patient may undergo a lot of depression and lose of hope in life. Because of the severity of the disease, the patient may lose their job and this can negatively affect the family dependent on the patient as income to support and provide for family members would no longer be there.

2.There are various signs and symptoms associated with exogenous Cushing’s syndrome. A common sign associated with the disease is weight gain and deposition of fatty tissue around the belly and formation of a buffalo hump between the shoulders. The patient as is the case of Sharon presents with a moon face that is the face becomes rounder. In addition to these, it can exacerbate obesity in individuals with the condition as there is increased fat deposition in these tissues. The pathophysiology behind these fat related signs and symptoms is the fact that Cushing’s syndrome is as a result of imbalances within the metabolic system of carbohydrates in the body (Nieman, 2018).

Cortisol is a hormone that is responsible for the metabolism of carbohydrates and fat within the body. If there is increased cortisol production or high levels of the same due to exogenous Cushing’s syndrome, metabolism of these fats and carbohydrates is affected leading to uneven distribution of fat and hence the presentation of central obesity and other signs. Another major sign associated with exogenous Cushing’s syndrome is increased blood pressure and this can cause a serious health crisis. According to Pineyro et al. (2019), hypertension is one of the major complications of the disease and it results from increased cardiac output or increased peripheral resistance. Since Cushing’s syndrome alters metabolism of carbohydrates, there might be increased sugar levels within the blood. This high blood sugar levels is also associated with diabetes and can alter blood vessels leading to increased peripheral resistance hence a high blood pressure. 

High sugar levels can also significantly affect blood volume and hence lead to increased cardiac output hence hypertension. Another sign and symptom associated with the condition is osteoporosis. This is a condition that affects the bones whereby there is degradation and use up of bones at extreme levels. It occurs when there is more bone resorption as compared to bone deposition. According to O’brien et al. (2018), the patient may present with shortened femurs and pain within the skeletal system. There is therefore need for careful monitoring. The pathophysiology behind this presentation is the fact that high cortisol and glucocorticoid levels affect bone metabolism by enhancing resorption of bone.

Signs and Symptoms of Exogenous Cushing’s Syndrome

3.Ms. Maureen was given a dose of prednisolone which she was taking daily to manage her rheumatic arthritis condition. This drug lies under the bigger classification of drugs referred to as corticosteroids. Corticosteroids have a series of important pharmacodynamics and pharmacokinetics. The pharmacodynamics focusses mainly on the mechanism of action of the drugs. Corticosteroids act by diffusing into the cells and binding into cytosolic receptors reversibly (Rainsbury et al, 2017). The anti-inflammatory process is quite a long process that requires a varied interaction of receptors and pathways in order to be effected. Corticosteroids act by altering synthesis of important enzymes and proteins by interacting with the messenger RNA and the DNA itself as a whole. An important protein referred to as lipocortin is important in imparting corticosteroids effects.

The pharmacokinetics mainly involves the aspects of absorption, distribution, metabolism and elimination or excretion of the drugs. Cortisol is found in blood in its free form. It binds to a corticosteroid binding globulin. Therapeutic corticosteroids such as prednisolone are rapidly absorbed after oral administration and reach peak plasma levels after 1 to 3 hours (Andela et al, 2015). Prednisolone is considered to be pharmacologically active as compared to its interconvertible subtype prednisone. The bioavailability of the drug is about 80%. It is dose dependent and the volume of distribution and clearance increases with the more of the drug dose is taken. It is therefore well distributed in the body. Plasma clearance of the drug is dependent on the dose intake and is longer with increased drug intake. Metabolism of corticosteroids mainly occurs in the liver with the processes of conjugation and glucuronidation taking place. Excretion of the drugs is via the renal route and metabolism of the drugs aims at diminishing their physiological activity and increasing water solubility. This helps in excretion by the kidney. 

4.Exogenous Cushing’s syndrome like any other medical condition requires attention and careful monitoring of the patients. Nursing care plans, interventions and rationales are of importance in ensuring the patient is well managed. Important nursing interventions involve assessing the risks associated with the disease and helping prevent exposure of the patient to more of these risks. In this medical case, it is important for the nurse to assess signs of circulatory overload. This can be done by checking for respiratory crackles, cyanosis, edema formation, distended neck veins and dyspnea (Bansal et al, 2015). This will assist in immediate intervention as it would mean that the glucocorticoid levels are so high that they predispose the patient to excessive water retention.

Pharmacodynamics and Pharmacokinetics of Corticosteroids

It is important for the nurse to monitor important vitals such as blood pressure levels and heart rate. Exogenous Cushing’s syndrome is highly associated with elevated blood pressure and therefore the rationale for this would be ensure that the patient is in a stable condition and offer insight on the effectiveness of the medications given in managing the condition. The nurse may also administer anti hypertensives where the blood pressure is highly elevated to control the condition from worsening. It is important for the patient to be advised on low fluid intake and to be given a healthy diet plan (Assié, 2018, June). Assessment of the skin frequently to look for signs of redness and skin tearing is an important nursing intervention. This is because the condition causes damage of important dermal proteins hence altering the skin integrity and predisposing the patient to bruising and injury. It is important to manage this conditions whenever detected. 

Since the condition causes osteoporosis, it is important to assess the patient for decreased height and kyphosis. This will help in monitoring progress of the patient in the healing process. Since diabetes is a risk factor associated to Cushing’s syndrome, it is important to obtain information concerning any history of the disease and also incidences of poor wound healing so as to aid in intervention process. Since the syndrome is associated with muscle loss and poor body structure, it is important to encourage a high protein diet so that the patient maintains a healthy body structure. Low carbohydrate intake should always be discouraged in any Cushing’s disease as high cortisol levels elevate blood sugar (Gottiganti et al, 2017).

The disease predisposes individuals to the risk of contracting other infections. This is because corticosteroids jeopardize the integrity of the immune system. It is necessary for the nurse or care provider to closely monitor the patient for any signs of infection and act promptly to ensure they are managed. According to Pereira et al. (2016), increased use of corticosteroids associated with the syndrome can cause a fungal infection in the patient. It is therefore of necessity for the nurse to inspect the patient for such signs and intervene. It is important to assess the patient’s level of knowledge as far as the Exogenous Cushing’s syndrome is involved and offer adequate health education where the knowledge is limited so as to prevent future recurrence and also exacerbation of the condition. 

References

Andela, C. D., van Haalen, F. M., Ragnarsson, O., Papakokkinou, E., Johannsson, G., Santos, A., … & Pereira, A. M. (2015). Mechanisms in endocrinology: Cushing’s syndrome causes irreversible effects on the human brain: a systematic review of structural and functional magnetic resonance imaging studies. European journal of endocrinology, 173(1), R1-R14.

Assié, G. (2018, June). Genomic insights into Cushing syndrome. In Annales d’endocrinologie (Vol. 79, No. 3, pp. 119-122). Elsevier Masson.

Bansal, V., El Asmar, N., Selman, W. R., & Arafah, B. M. (2015). Pitfalls in the diagnosis and management of Cushing’s syndrome. Neurosurgical focus, 38(2), E4.

Gottiganti, G., Badhvel, J. K., Dornadula, G. R., Petam, A. K., & Pothugunt, B. C. (2017). Case report on dexamethasone induced iatrogenic cushing syndrome. International Journal of Pharmaceutical Sciences Review and Research, 45, 29.

Morgan, S. A., Hassan-Smith, Z. K., & Lavery, G. G. (2016). Mechanisms in endocrinology: tissue-specific activation of cortisol in Cushing’s syndrome. European journal of endocrinology, 175(2), R81-R87.

Nieman, L. K. (2018). Recent Updates on the Diagnosis and Management of Cushing’s Syndrome. Endocrinology and Metabolism, 33(2), 139-146.

O’brien, K. F., DeKlotz, C. M. C., & Silverman, R. A. (2018). Exogenous Cushing syndrome from an unexpected source of systemic steroids. Pediatric dermatology, 35(3), e196-e197.

Pappachan, J. M., Hariman, C., Edavalath, M., Waldron, J., & Hanna, F. W. (2017). Cushing’s syndrome: a practical approach to diagnosis and differential diagnoses. Journal of clinical pathology, 70(4), 350-359.

Pereira, M. T., Ferreira, L., Horta, A. A., & de Carvalho, A. C. (2016). Exogenous Cushing’s syndrome as a result of ritonavir–budesonide interaction–A case report. HIV & AIDS Review, 15(2), 91-93.

Pineyro, M. M., Redes, L., De Mattos, S., Sanchez, L., Brignardello, E., Bianchi, V., … & Viola, M. (2019). Factitious Cushing’s Syndrome: A Diagnosis to Consider When Evaluating Hypercortisolism. Frontiers in Endocrinology, 10.

Pivonello, R., Isidori, A. M., De Martino, M. C., Newell-Price, J., Biller, B. M., & Colao, A. (2016). Complications of Cushing’s syndrome: state of the art. The Lancet Diabetes & Endocrinology, 4(7), 611-629.

Rainsbury, P. G., Sharp, J., Tappin, A., Hussey, M., Lenko, A., & Foster, C. (2017). Ritonavir and topical ocular corticosteroid induced Cushing’s syndrome in an adolescent with HIV-1 infection. The Pediatric infectious disease journal, 36(5), 502-503.

Sharma, S. T., Nieman, L. K., & Feelders, R. A. (2015). Cushing’s syndrome: epidemiology and developments in disease management. Clinical epidemiology, 7, 281.