Drug-induced endocrine disorders in the intensive care unit

Clinical manifestations and treatment of hypopituitarism due to traumatic brain injury

Traumatic brain injury (TBI) is a global health problem with rising incidence. In many patients, pituitary hormone deficiencies after TBI are transient; however, in some cases, they can persist or develop in the chronic phase. Post-traumatic hypopituitarism has a variable clinical course, reflecting its complex pathophysiology and incompletely understood risk factors. The diagnosis can be challenging, because symptoms of hypopituitarism may overlap with other TBI manifestations. Confirmatory endocrine testing is often required for diagnosis. Untreated chronic hypopituitarism can adversely affect physical, neurocognitive, and psychosocial rehabilitation; body composition; glucose metabolism; bone metabolism; and quality of life. Screening for hypopituitarism is recommended after moderate or severe TBI and for selected patients with mild TBI and suggestive clinical symptoms. Management requires an individualized multidisciplinary approach and consideration of endocrine pathology. In this review, we discuss the clinical manifestations and current management standards for hypopituitarism in adults with TBI.

Glucose Metabolism and Stress Hyperglycemia in Critically Ill Children

Abnormalities in glucose metabolism and stress hyperglycemia (SH) are commonly seen in critically ill children. While SH may represent an adaptive stress response as a source of fuel for the body during the "fight or flight response" of critical illness, several studies have observed the association of SH with worse outcomes in different disease states. In addition to alterations in glucose metabolism and acquired insulin resistance from inflammation and organ dysfunction, specific intensive care unit (ICU) interventions can also affect glucose homeostasis and SH during critical illness. Common ICU interventions can mediate the development of SH in critical illness. The strategy of tight glucose control combined with intensive insulin therapy (TGC-IIT) has been well studied to improve outcomes in both adult and pediatric critical illness. Though early single-center studies of TGC-IIT observed benefits with better outcomes albeit with greater incidence of hypoglycemia, subsequent larger multicenter studies in both children and adults have not conclusively demonstrated benefits and have even observed harm. Several possible reasons for these contrasting results include differences in patient populations, glycemic control targets, and glucose control protocols including nutrition support, and variability in achieving these targets, measurement methods, and expertise in protocol implementation. Future studies may need to individualize management of SH in critically ill children with improved monitoring of indices of glycemia utilizing continuous sensors and closed-loop insulin administration.

[Other specific types of diabetes and exocrine pancreatic insufficiency (update 2023)]

The heterogenous category "specific types of diabetes due to other causes" encompasses disturbances in glucose metabolism due to other endocrine disorders such as acromegaly or hypercortisolism, drug-induced diabetes (e.g. antipsychotic medications, glucocorticoids, immunosuppressive agents, highly active antiretroviral therapy (HAART), checkpoint inhibitors), genetic forms of diabetes (e.g. Maturity Onset Diabetes of the Young (MODY), neonatal diabetes, Down‑, Klinefelter- and Turner Syndrome), pancreatogenic diabetes (e.g. postoperatively, pancreatitis, pancreatic cancer, haemochromatosis, cystic fibrosis), and some rare autoimmune or infectious forms of diabetes. Diagnosis of specific diabetes types might influence therapeutic considerations. Exocrine pancreatic insufficiency is not only found in patients with pancreatogenic diabetes but is also frequently seen in type 1 and long-standing type 2 diabetes.

Thyroid scintigraphy in the era of fine-needle aspiration cytology

PURPOSE

To evaluate whether thyroid scintigraphy would alter the clinical management of patients referred for fine-needle aspiration cytology (FNA).

METHODS

We reviewed the medical and imaging records of patients referred to our Department between 2016 and 2019. All the patients had to take a serum thyrotropin test administered in our hospital at least two months before the FNA; where the TSH level was ≤1.5 mIU/L, the patients were subjected to a scan and subsequently to FNA, where indicated. We selected only healthy patients with no previous history of thyroid disease, who were not taking any drugs and who had a TSH level of ≤1.5 mIU/L. We excluded patients with multinodular goitre.

RESULTS

A total of 176 patients were analysed. A total of 67/176 patients (38%) showed a serum of TSH ≤ 0.27 mIU/L. Scintigraphy identified a hot nodule in 142 lesions (80.7%), a warm nodule in 8 lesions (4.5%) and a cold nodule in 26 lesions (14.8%). The ROC curve analysis indicated that a TSH value of ≤0.42 mIU/L identified patients with hyperfunctioning nodules with a sensitivity of 65% and a specificity of 77%. All patients with cold and warm nodules were submitted to FNA: 22/26 (85%) and 5/8 (63%) lesions showed suspected malignancy or were compatible with malignancy, respectively.

CONCLUSION

Speculating on our data, if we had subjected our patients to FNA as indicated by the 2015 ATA guidelines, we would have subjected 117 patients to cytology, from whom 83 had undetected hot nodules. Conversely, by adopting scintigraphy for all patients with TSH ≤ 1.5 mIU/L, 109 patients have avoided FNA. However, our study was performed in a region with a history of mild iodine deficiency. Therefore, we cannot claim that our observation is valid for patients born and living in areas with sufficient iodine uptake. We recommend thyroid scintigraphy for treating single thyroid nodules in euthyroid patients born and living in regions with an iodine deficiency, when TSH levels are below 1.5 mIU/L before FNA.

The adverse effects of psychotropic drugs as an endocrine disrupting chemicals on the hypothalamic-pituitary regulation in male

Adverse effects of drugs on male reproductive system can be categorized as pre-testicular, testicular, and post-testicular. Pre-testicular adverse effects disrupt the hypothalamic-pituitary-gonadal (HPG) axis, generally by interfering with endocrine function. It is known that the HPG axis has roles in the maintenance of spermatogenesis and sexual function. The hypothalamus secretes gonadotropin-releasing hormone (GnRH) which enters the hypophyseal portal system to stimulate the anterior pituitary. The anterior pituitary secretes gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) which are vital for spermatogenesis, into the blood. The FSH stimulates the Sertoli cells for the production of regulatory molecules and nutrients needed for the maintenance of spermatogenesis, while the LH stimulates the Leydig cells to produce and secrete testosterone. Many neurotransmitters influence the hypothalamic-pituitary regulation, consequently the HPG axis, and can consequently affect spermatogenesis and sexual function. Psychotropic drugs including antipsychotics, antidepressants, and mood stabilizers that all commonly modulate dopamine, serotonin, and GABA, can affect male spermatogenesis and sexual function by impairment of the hypothalamic-pituitary regulation, act like endocrine-disrupting chemicals. Otherwise, studies have shown the relationship between decreased sperm quality and psychotropic drugs treatment. Therefore, it is important to investigate the adverse reproductive effects of psychotropic drugs which are frequently used during reproductive ages in males and to determine the role of the hypothalamic-pituitary regulation axis on possible pathologies.

[Other specific types of diabetes and exocrine pancreatic insufficiency (Update 2019)]

The heterogenous catagory "specific types of diabetes due to other causes" encompasses disturbances in glucose metabolism due to other endocrine disorders such as acromegaly or hypercortisolism, drug-induced diabetes (e. g. antipsychotic medications, glucocorticoids, immunosuppressive agents, highly active antiretroviral therapy (HAART)), genetic forms of diabetes (e. g. Maturity Onset Diabetes of the Young (MODY), neonatal diabetes, Down Syndrome, Klinefelter Syndrome, Turner Syndrome), pancreatogenic diabetes (e. g. postoperatively, pancreatitis, pancreatic cancer, haemochromatosis, cystic fibrosis), and some rare autoimmune or infectious forms of diabetes. Diagnosis of specific diabetes types might influence therapeutic considerations. Exocrine pancreatic insufficiency is not only found in patients with pancreatogenic diabetes but is also frequently seen in type 1 and long-standing type 2 diabetes.

Pituitary and/or hypothalamic dysfunction following moderate to severe traumatic brain injury: Current perspectives

There is an increasing deliberation regarding hypopituitarism following traumatic brain injury (TBI) and recent data have suggested that pituitary dysfunction is very common among survivors of patients having moderate-severe TBI which may evolve or resolve over time. Due to high prevalence of pituitary dysfunction after moderate-severe TBI and its association with increased morbidity and poor recovery and the fact that it can be easily treated with hormone replacement, it has been suggested that early detection and treatment is necessary to prevent long-term neurological consequences. The cause of pituitary dysfunction after TBI is still not well understood, but evidence suggests few possible primary and secondary causes. Results of recent studies focusing on the incidence of hypopituitarism in the acute and chronic phases after TBI are varied in terms of severity and time of occurrence. Although the literature available does not show consistent values and there is difference in study parameters and diagnostic tests used, it is clear that pituitary dysfunction is very common after moderate to severe TBI and patients should be carefully monitored. The exact timing of development cannot be predicted but has suggested regular assessment of pituitary function up to 1 year after TBI. In this narrative review, we aim to explore the current evidence available regarding the incidence of pituitary dysfunction in acute and chronic phase post-TBI and recommendations for screening and follow-up in these patients. We will also focus light over areas in this field worthy of further investigation.

Pituitary dysfunction after traumatic brain injury: a clinical and pathophysiological approach

Traumatic brain injury (TBI) is a growing public health problem worldwide and is a leading cause of death and disability. The causes of TBI include motor vehicle accidents, which are the most common cause, falls, acts of violence, sports-related head traumas, and war accidents including blast-related brain injuries. Recently, pituitary dysfunction has also been described in boxers and kickboxers. Neuroendocrine dysfunction due to TBI was described for the first time in 1918. Only case reports and small case series were reported until 2000, but since then pituitary function in TBI victims has been investigated in more detail. The frequency of hypopituitarism after TBI varies widely among different studies (15-50% of the patients with TBI in most studies). The estimates of persistent hypopituitarism decrease to 12% if repeated testing is applied. GH is the most common hormone lost after TBI, followed by ACTH, gonadotropins (FSH and LH), and TSH. The underlying mechanisms responsible for pituitary dysfunction after TBI are not entirely clear; however, recent studies have shown that genetic predisposition and autoimmunity may have a role. Hypopituitarism after TBI may have a negative impact on the pace or degree of functional recovery and cognition. What is not clear is whether treatment of hypopituitarism has a beneficial effect on specific function. In this review, the current data related to anterior pituitary dysfunction after TBI in adult patients are updated, and guidelines for the diagnosis, follow-up strategies, and therapeutic approaches are reported.

Pituitary side effects of old and new drugs

INTRODUCTION

Pituitary function is influenced by several drugs, including anti-depressant, opioids, glucocorticoids, chemotherapeutic agents, immunomodulators and the newly developed tyrosine kinase inhibitors. In most instances, treatment with these drugs negatively affects pituitary function, but in rare cases an activation of specific hypothalamic-pituitary axes may be observed. Several of the observed pituitary side effects are reversible after drug withdrawal, but pituitary function deficiency may persist long-term. In addition to the well known drugs, recent evidence shows that also non-steroidal anti-inflammatory drugs impair gonadal axis at pituitary level, while antipsychotic phenothiazines alter TSH response to TRH and TSH levels. Atypical antipsychotics may decrease TRH-stimulated TSH. Tricyclic antidepressant drugs interfere with the hypothalamo-pituitary-thyroid axis by decreasing TSH response to TRH. Anabolic-androgenic steroids, marijuana, cocaine, methamphetamines, and opioid narcotics negatively impact fertility, also acting at hypothalamic-pituitary level.

CONCLUSIONS

Many of the drugs administered routinely in the intensive care unit significantly impact the hypothalamic-pituitary axis. Therefore, an increased awareness on pituitary side effects of drugs commonly used in clinical practice is necessary in order to rule out possible pharmacological interference when assessing patients with pituitary deficiencies.

Clinical conundrums in management of hypothyroidism in critically ill geriatric patients

CONTEXT

Articles in various international and national bibliographic indices were extensively searched with an emphasis on thyroid and hypothyroid disorders, hypothyroidism in elderly hospitalized patients, hypothyroidism in critically ill geriatric population, thyroxine in elderly hypothyroid, drug interactions and thyroid hormones, and thyroid functions in elderly.

EVIDENCE ACQUISITION

Entrez (including PubMed), NIH.gov, Medscape.com, WebMD.com, MedHelp.org, Search Medica, MD consult, yahoo.com, and google.com were searched. Manual search was performed on various textbooks of medicine, critical care, pharmacology, and endocrinology.

RESULTS

Thyroid function tests in elderly hospitalized patients must be interpreted with circumspection. The elderly are often exposed to high iodide content and critical care settings. This may occur because of either decreased iodine excretion or very high intake of iodine. This is especially true for elderly population with underlying acute or chronic kidney diseases or both. Amiodarone, with a very high iodine content, is also often used in this set of population. Moreover, other medications including iodinated contrast are often used in the critical care settings. These may affect different steps of thyroid hormone metabolism, and thereby complicate the interpretation of thyroid function tests.

CONCLUSIONS

The current review is aimed at analyzing and managing various clinical aspects of hypothyroidism in hospitalized elderly, and critically ill geriatric patients.

Ultrasound dilution: an accurate means of determining cardiac output in children

BACKGROUND

Cardiac output is a useful measure of myocardial performance. Cardiac output monitoring is frequently performed in critically ill adults to guide physicians' treatment strategies. However, standard methods of determining cardiac output in children are not without risk and can be problematic secondary to their invasive nature and other technical problems. The COstatus system (Transonic Systems, NY), which is based on ultrasound dilution technology, works off in situ catheters and uses an innocuous indicator to allow for routine measurements of cardiac output and blood volumes in pediatric patients. The purpose of this study was to validate cardiac output measured by the COstatus system with those obtained by the clinical standard technique of pulmonary artery thermodilution.

METHODS

This was a prospective evaluation performed at a single institution. Any child with a structurally normal heart undergoing hemodynamic evaluation in the cardiac catheterization laboratory was included. A prograde right heart catheterization was performed, and cardiac output was first determined by using the pulmonary artery thermodilution technique. Thermodilution results were then compared with cardiac output measurements obtained using the COstatus system. The results were analyzed by standard correlation, Bland-Altman, and Critchley and Critchley analyses.

RESULTS

Twenty-eight patients were evaluated with a median age of 8 yrs and a median weight of 31 kg. The mean thermodilution cardiac index = 3.18 L/min (± 1.35 L/min), and the mean COstatus system cardiac index = 3.17 L/min (± 1.31 L/min). Standard Pearson correlation tests revealed an excellent correlation coefficient of 0.95 (p < .0001). Bland-Altman analysis revealed good clinical agreement with a mean difference of -0.004 L/min with a precision of 0.8 L/min at 2 SD. A percentage error of 25.4% was noticed in this study, which is less than the clinically acceptable limit.

CONCLUSION

The ultrasound dilution technique of determining cardiac output using the COstatus system provides a less invasive method than the traditional pulmonary artery thermodilution for accurately determining cardiac output in children. This is the first validation of the COstatus system in pediatric patients. Further studies are required to establish its accuracy in pediatric patients with cardiac shunts and other hemodynamically unstable conditions.

Stress hyperglycemia in pediatric critical illness: the intensive care unit adds to the stress!

Stress hyperglycemia (SH) commonly occurs during critical illness in children. The historical view that SH is beneficial has been questioned in light of evidence that demonstrates the association of SH with worse outcomes. In addition to intrinsic changes in glucose metabolism and development of insulin resistance, specific intensive care unit (ICU) practices may influence the development of SH during critical illness. Mechanical ventilation, vasoactive infusions, renal replacement therapies, cardiopulmonary bypass and extracorporeal life support, therapeutic hypothermia, prolonged immobility, nutrition support practices, and the use of medications are all known to mediate development of SH in critical illness. Tight glucose control (TGC) to manage SH has emerged as a promising therapy to improve outcomes in critically ill adults, but results have been inconclusive. Large variations in ICU practices across studies likely resulted in inconsistent results. Future studies of TGC need to take into account the impact of commonly used ICU practices and, ideally, standardize protocols in an attempt to improve the accuracy of conclusions from such studies.

Baseline insulin/glucose ratio as a marker for the clinical course of hyperglycemic critically ill children treated with insulin

OBJECTIVE

The objective of this study was to investigate the relations of baseline insulin/glucose ratio to the clinical course of critically ill children. Such information will provide insight into the pathophysiologic mechanisms leading to hyperglycemia and will optimize preventive and therapeutic measures for hyperglycemia in critically ill children.

METHODS

Sixty-four consecutively admitted critically ill children with hyperglycemia, defined as a blood glucose level higher than 8 mmol/L (>145 mg/dL) and treated with insulin according to a glucose-control protocol, were included. Demographic data and clinical and laboratory parameters were collected. Insulin sensitivity was investigated by calculating the ratio of insulin to the blood glucose level just before the start of insulin administration. Results are expressed as median (range).

RESULTS

Sixty-four children (24 girls) 7.0 y of age (0.3-16.9 y) with various diagnoses were included. A hyperinsulinemic response, indicated by an increased insulin/glucose ratio (>18 pmol/mmol), was seen in 55% of children. The durations of insulin therapy, mechanical ventilation, and pediatric intensive care unit length of stay in children with a hyperinsulinemic response were longer than in children with a hypoinsulinemic response.

CONCLUSION

Hyper- and hypoinsulinemic responses play a role in the occurrence of hyperglycemia in critically ill children. Each is associated with a particular clinical course after the initiation of insulin therapy. It would be worthwhile to further investigate if the insulinemic response to hyperglycemia, determined by the insulin/glucose ratio in combination with the type of organ dysfunction, could be used in clinical practice to determine the need for insulin therapy.