Thyroid testing in acutely ill patients may be an expensive distraction

A Causality between Thyroid Function and Bone Mineral Density in Childhood: Abnormal Thyrotropin May Be Another Pediatric Predictor of Bone Fragility

Low bone mass can occur in children and adolescents with numerous chronic conditions; however, the influence of abnormal thyroid hormone and thyroid-stimulating hormone (TSH) levels on low bone mineral density (BMD) in children and adolescents remains controversial. Investigating the effects of excessive or deficient thyroid hormone and TSH levels on the risk of childhood bone fragility may provide a better understanding of the role of thyroid function on bone density in the pediatric population. The triiodothyronine (T3), thyroxine (T4), and TSH levels and BMD of 619 children diagnosed with various underlying conditions and whose treatment was completed were simultaneously assessed. The T3, free thyroxine (FT4), and TSH levels were subcategorized based on the age-matched reference range, and the lumbar spine BMD (LSBMD) data were compared. The mean LSBMD z-score was 0.49 ± 1.28, while T3, FT4, and TSH levels were 1.25 ± 0.29 ng/mL, 1.28 ± 0.19 ng/dL, and 2.76 ± 1.87 µU/mL, respectively. Both lumbar and femoral BMD z-scores were lower in children with abnormal TSH levels. TSH abnormality was the strongest risk factor for decreased LSBMD z-scores, and thus could be an early indicator of low BMD in children and adolescents with various underlying conditions.

Indications for ordering thyroid-stimulating hormone in noncritically ill adult inpatients-A Delphi consensus recommendation

BACKGROUND

Thyroid-stimulating hormone (TSH) is ordered commonly among inpatients, but the possibility of nonthyroidal illness syndrome challenges interpretation.

OBJECTIVE

Our objective was to obtain Canadian consensus on appropriate indications for ordering TSH in the first 48 h following presentation of a noncritically ill internal medicine patient.

DESIGN, SETTING AND PARTICIPANTS

Canadian endocrinologists with inpatient expertise were invited via snowball sampling to an online 3-round Delphi study. Main Outcome and Measures using a 6-point Likert scale, they rated 58 indications on appropriateness for measuring TSH in medical inpatients. These indications included clinical presentations, signs, and symptoms. Items that reached consensus and agreement (≥80% of participants selecting a rating of 5 or 6 on the Likert scale) were tabulated and dropped after each round. Qualitative analysis of comments identified additional contextual considerations as themes.

RESULTS

There were 45 participants (academic setting: 84%) representing 8 provinces (Ontario: 64%). Rounds 2 and 3 were completed by 42 and 33 participants, respectively. Nine indications reached consensus and agreement: presumed myxedema coma, presumed thyroid storm, atrial fibrillation/flutter, euvolemic hyponatremia, proptosis, adrenal insufficiency, hypothermia, thyroid medication noncompliance, and goiter. There was also agreement that two contextual considerations identified in thematic analysis, including a recent abnormal outpatient TSH, and the presence of other findings of thyroid dysfunction, would significantly change some mid-range responses.

CONCLUSIONS

Canadian experts agreed upon nine specific indications for ordering an inpatient TSH, with others requiring consideration of previous TSH measurement and clinical context.

Impact of thyroid function screening in a large cohort of patients admitted to an emergency department

BACKGROUND

Thyroid dysfunctions are highly prevalent and can worsen underlying cardiopathies, but despite that the routine screening of thyroid function in the Emergency Department (ED) setting is not generally recommended.

OBJECTIVE

To understand if staff training and implementation of rapid TSH screening (rTSH) could improve the management of patients arrived in the ED. Specifically, we aimed at evaluating the prevalence of undiagnosed thyroid diseases among ED patients; the effects of educational meetings in the clinical decision-making process; the usefulness of rTSH, in terms of variation of either the clinical work out or the existing treatment.

DESIGN

Retrospective case-control study of 9227 patients managed in the ED of an academic institution. rTSH was routinely available for all patients, who were divided into rTSH-YES and rTSH-NO groups.

RESULTS

We included 4243 and 4984  patients in the rTSH-YES and rTSH-NO group, respectively. Trained personnel uncovered a high prevalence of undiagnosed thyroid dysfunction (7%). The diagnosis in the ED of heart failure, history of thyroid diseases, contrast media/amiodarone administration and female gender were independently associated with an increased likelihood to have thyroid dysfunction. The rTSH improved the clinical outcome by (a) appropriate treatment of an underlying clinical condition causing ED entrance, (b) appropriate prophylaxis in patients requiring contrast media, (c) uncovering incorrect treatments, with 60% of patients on levothyroxine requiring a dose reduction.

CONCLUSIONS

The rTSH in the ED revealed a high prevalence of untreated thyroid disorders with a major impact on following interventions. The training of a multidisciplinary team is crucial in driving the correct decision-making process.

Thyroid hormone alterations in critically and non-critically ill patients with SARS-CoV-2 infection

OBJECTIVE

Following the evolution of COVID-19 pandemic, reports pointed on a high prevalence of thyroiditis-related thyrotoxicosis. Interpretation of thyroid tests during illness, however, is hampered by changes occurring in the context of non-thyroidal illness syndrome (NTIS). In order to elucidate these findings, we studied thyroid function in carefully selected cohorts of COVID-19 positive and negative patients.

DESIGN

Cohort observational study.

METHODS

We measured TSH, FT4, T3 within 24 h of admission in 196 patients without thyroid disease and/or confounding medications. In this study, 102 patients were SARS-CoV-2 positive; 41 admitted in the ICU, 46 in the ward and 15 outpatients. Controls consisted of 94 SARS-CoV-2 negative patients; 39 in the ICU and 55 in the ward. We designated the thyroid hormone patterns as consistent with NTIS, thyrotoxicosis and hypothyroidism.

RESULTS

A NTIS pattern was encountered in 60% of ICU and 36% of ward patients, with similar frequencies between SARS-CoV-2 positive and negative patients (46.0% vs 46.8%, P = NS). A thyrotoxicosis pattern was observed in 14.6% SARS-CoV-2 ICU patients vs 7.7% in ICU negative (P = NS) and, overall in 8.8% of SARS-CoV-2 positive vs 7.4% of negative patients. In these patients, thyroglobulin levels were similar to those with normal thyroid function or NTIS. The hypothyroidism pattern was rare.

CONCLUSIONS

NTIS pattern is common and relates to the severity of disease rather than SARS-CoV-2 infection. A thyrotoxicosis pattern is less frequently observed with similar frequency between patients with and without COVID-19. It is suggested that thyroid hormone monitoring in COVID-19 should not differ from other critically ill patients.

The significance of high thyroxine in hospitalized patients with low thyroid-stimulating hormone

PURPOSE

There is scarce data about the interpretation of high thyroid hormone levels in hospitalized patients. We wished to investigate the significance of high thyroxine (T4) in hospitalized patients with low TSH.

METHODS

We conducted a retrospective study of data from patients in nonsurgical departments. Three groups of random patients with low TSH were defined and compared: 123 patients with only high FT4 levels (T4 group), 82 with high FT3 levels with or without high FT4 level (T3 group), and 119 with low FT3 and FT4 level in the lower half of the norm and below (NTIS group).

RESULTS

The primary cause of admission in the T4 and NTIS groups was infectious disease, 20.3% and 40.3%, respectively; while in the T3 group it was cardiovascular disease (31.7%). The T4 group but not T3 group had epidemiological and clinical characteristics similar to the NTIS group. The T4 group had a significant correlation between increased CRP levels and decreased FT3 (r = 0.366, p < 0.001) similar to the NTIS group. The T3 group had a borderline correlation between increased FT3 and FT4 levels (r = 0.208, p = 0.061) but the T4 group did not.

CONCLUSIONS

The combination of low TSH and high FT4 levels in hospitalized patient is usually caused by nonthyroidal illness combined with drug effects. This thyroid function disturbance is common in hospitalized patients and if the FT3 level is below the middle of the norm, treatment is probably unnecessary.

The hypothalamus-pituitary-thyroid (HPT)-axis and its role in physiology and pathophysiology of other hypothalamus-pituitary functions

The hypothalamus-pituitary-thyroid axis is one of several hormone regulatory systems from the hypothalamus to the pituitary and ultimately to the peripheral target organs. The hypothalamus and the pituitary gland are in close anatomical proximity at the base of the brain and extended through the pituitary stalk to the sella turcica. The pituitary stalk allows passage of stimulatory and inhibitory hormones and other signal molecules. The target organs are placed in the periphery and function through stimulation/inhibition by the circulating pituitary hormones. The several hypothalamus-pituitary-target organ axis systems interact in very sophisticated and complicated ways and for many of them the interactive and integrated mechanisms are still not quite clear. The diagnosis of central hypothyroidism is complicated by itself but challenged further by concomitant affection of other hypothalamus-pituitary-hormone axes, the dysfunction of which influences the diagnosis of central hypothyroidism. Treatment of both the central hypothyroidism and the other hypothalamus-pituitary axes also influence the function of the others by complex mechanisms involving both central and peripheral mechanisms. Clinicians managing patients with neuroendocrine disorders should become aware of the strong integrative influence from each hypothalamus-pituitary-hormone axis on the physiology and pathophysiology of central hypothyroidism. As an aid in this direction the present review summarizes and highlights the importance of the hypothalamus-pituitary-thyroid axis, pitfalls in diagnosing central hypothyroidism, diagnosing/testing central hypothyroidism in relation to panhypopituitarism, pointing at interactions of the thyroid function with other pituitary hormones, as well as local hypothalamic neurotransmitters and gut-brain hormones. Furthermore, the treatment effect of each axis on the regulation of the others is described. Finally, these complicating aspects require stringent diagnostic testing, particularly in clinical settings with lower or at least altered à priori likelihood of hypopituitarism than in former obvious clinical patient presentations.

Intravenous levothyroxine stewardship program at a tertiary academic medical center

PURPOSE

Based on the pharmacokinetic profile of levothyroxine, a 3-day hold guideline for adult patients ordered for intravenous (IV) levothyroxine was implemented at a tertiary academic medical center. The purpose of this study was to evaluate the impact of the implementation of an IV levothyroxine hold guideline.

METHODS

This single-center, retrospective analysis identified patients ordered for IV levothyroxine during a 13-week period before and after implementation of the guideline. The primary outcome was guideline adherence, defined as full implementation of the 3-day hold. Secondary outcomes included the number of IV levothyroxine administrations avoided in the post-guideline group, extrapolated yearly cost avoidance (EYCA) after guideline implementation, reasons for guideline non-adherence, and number of safety reports involving IV levothyroxine.

RESULTS

A total of 166 and 134 patients met inclusion criteria for the pre- and post-guideline groups, respectively. Guideline adherence was observed in 94 (70.1%) patients, resulting in 276 vials saved in the 13-week post-guideline period, which translated to an EYCA of $139,877. Forty orders (29.9%) were non-adherent to the guideline, with the most common reason stated as nil per os (NPO). No difference in safety outcomes was seen between the pre- and post-guideline groups, as evidenced by 1 safety report in each group.

CONCLUSION

We observed a high rate of adherence to an IV levothyroxine hold guideline. This was associated with a substantial cost savings over the study period with no increase in reported safety events. To our knowledge, this is the first published report of an inpatient IV levothyroxine 3-day hold guideline.

The Clinical Approach on Receipt of an Unexpected Laboratory Test Result

Approximately 70% of all healthcare decisions affecting diagnosis and treatment involve the use of tests performed within pathology laboratories. The utilisation of diagnostic laboratory services continues to increase, with growth both in volume of tests requested, as well as in the breadth of test repertoire. Every year in the United Kingdom, approximately 1 billion tests are run in hospital laboratories, equivalent to 14 tests per person. Fifty million tests are requested in primary care. Accordingly, there is an inevitable increase in the number of unexpected laboratory results which clinicians review. This is an important, and potentially time-consuming, issue, which we considered to merit a more detailed discussion. Unexpected laboratory results may be critical or non-critical in nature. They may be absolutely genuine, reflecting a clinical change in the patient’s condition, a differential diagnosis not previously considered, or an additional test specifically added by the laboratory. However, such results may also occur due to a variety of different circumstances, including much more rarely laboratory error. As there is little published evidence or guidance available, herein we discuss aspects of the clinical approach for physicians after receiving an unexpected laboratory test result.

Impact of high triglyceride/high-density lipoprotein cholesterol ratio (insulin resistance) in ST-segment elevation myocardial infarction

The ratio of triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) has been proposed as an easily obtainable atherogenic marker and high TG/HDL-C ratio is associated with insulin resistance. This study investigated the associated between a high TG/HDL-C ratio and cardiovascular mortality in patients with ST-segment elevation myocardial infarction (STEMI), with or without diabetes mellitus (DM).Between January 2005 and December 2014, 1661 patients with STEMI underwent primary percutaneous coronary intervention in our hospital. Of these, 289 were classified into group 1 (with both DM and a high TG/HDL-C ratio), 295 into group 2 (with DM, but without a high TG/HDL-C ratio), 501 into group 3 (without DM, but a high TG/HDL-C ratio), and 576 into group 4 (without DM or a high TG/HDL-C ratio).Older age, longer chest pain to reperfusion time, poor hemodynamic condition, and higher prevalence of multiple vessel coronary artery disease were noted in those with DM. Poor outcomes including higher 30-day and 1-year cardiovascular mortality and all-cause mortality rates were noted in those with DM but without a high TG/HDL-C ratio. Patients with DM but without a high TG/HDL-C ratio had a Hazard ratio of 3.637 for cardiovascular mortality relative to those without DM, but without a high TG/HDL-C ratio.Even though a high TG/HDL-C ratio is associated with insulin resistance, patients with or without DM, but with a high TG/HDL-C ratio had better 30-day and 1-year outcomes.

Low Yield of Thyroid-Function Tests in Adult Hospitalized Patients - A Retrospective Analysis

BACKGROUND

In the US, serum thyroid-stimulating hormone (TSH) and thyroxine measurements are the fourth- and tenth-commonest laboratory tests ordered, respectively. Diagnosis of thyroid disorder requires clinical suspicion supported by laboratory values. However, in the setting of acute illness, both the clinical and laboratory pictures can be confounded.

OBJECTIVE

To study clinical outcomes and derangement patterns of inpatient thyroid-function tests.

DESIGN

This retrospective study was conducted at an academic center on admissions aged ≥18 years and TSH tests performed over a 1-year period. Admissions with active pregnancy and/or prior thyroid-related diagnosis were excluded.

MAIN OUTCOMES

Clinical outcomes were divided based on new diagnosis of thyroid-related disorder, newly prescribed thyroxine replacement, or antithyroid drugs/ endocrinology referrals, or both. In order to analyze the derangement patterns of abnormal TSH, only the results of the first test ordered were considered (as some admissions had multiple TSH tests ordered).

RESULTS

A total of 7,204 admissions aged ≥18 years had TSH tests done. Of these, 1,912 were excluded. Of the 5,292 admissions with no prior thyroid disorder or active pregnancy, 183 (3.46%) were assigned a new diagnosis of thyroid-related disorder, 54 (1.02%) received treatment/referral, and 46 (0.87%) received both a new diagnosis and treatment/referral. Based on the TSH results (reference range 0.42-4.0 mIU/L) of the 5,292 admissions, 4,312 (81.5%) and 980 (18.5%) admissions were flagged normal and abnormal, respectively. Of the 980 admissions with one or more abnormal TSH results, 21 (2.14%) had first ordered TSH <0.05 mIU/L, 855 (87.25%) admissions had first TSH result between 0.05-10 mIU/L, and lastly 104 (10.61%) were >10 mIU/L.

CONCLUSION

There is low value in testing inpatients for thyroid disorders, and testing comes at significant expense to the health-care system.

Frequency of thyroid function tests and examinations in participants of a population-based study

BACKGROUND

Thyroid disorders are common in the adult German population. Little is known about guideline implementation in clinical practice and the prevalence of diagnostic procedures in ambulatory care. The study aims to investigate the use of thyroid hormone measurements, thyroid ultrasound, thyroid scintiscan and associated costs in ambulatory care at population level.

METHODS

Data were derived from two independent population-based cohorts of the Study of Health In Pomerania (SHIP). Ambulatory billing data from the Association of Statutory Health Insurance Physicians Mecklenburg-Vorpommern were individually linked for the period 2002-2016 with SHIP data. The main outcomes were the frequency of outpatient ultrasound, scintiscan, serum TSH level measurement, free triiodothyronine (fT3) and free thyroxine (fT4) measurement, TSH-receptor-antibodies and microsomal antibodies measurement within 1 year and 3 years prior to the study entrance of the participants. Multinomial logistic regression models were used to assess the association of age, sex, thyroid medication intake and Charlson-Comorbidity-Index with frequency of TSH measurements and ultrasound examinations.

RESULTS

A total of 5552 participants (47% male, median age 55) were included in the analysis. 25% (1409/5552) had a diagnosed thyroid disorder or treatment, 40% (2191/5552) had clinical findings based on ultrasound or laboratory testing in SHIP only and 35% (1952/5552) neither a coded thyroid disorder or clinical finding nor thyroid medication. In the total study population 30% (1626/5552) received at least one TSH measurement, 6.8% (378/5552) at least one thyroid ultrasound and 2.6% (146/5552) at least one scintiscan within the past year before the study examination. Tests were performed more frequently in patients with thyroid medication and coded thyroid disorders. Hence, this group caused the highest expenditures.

CONCLUSIONS

Given the high prevalence of thyroid disorders, diagnostic and monitoring tests should be used rationally with regard to costs. TSH levels should be monitored regularly in patients on thyroid medication. A consensus on monitoring frequency and iteration of monitoring of morphological thyroid disorders with TSH and ultrasound and specific guideline recommendations are needed.

TRIAL REGISTRATION

Versorgungsforschung Deutschland (VfD_17_003880).

Altering standard admission order sets to promote clinical laboratory stewardship: a cohort quality improvement study

BACKGROUND

Careful design of preprinted order sets is needed to prevent medical overuse. Recent work suggests that removing a single checkbox from an order set changes physicians' clinical decision-making.

LOCAL PROBLEM

During a 2-month period, our coronary care unit (CCU) ordered almost eight times as many serum thyroid-stimulating hormone (TSH) tests as our neighbouring intensive care unit, many without a reasonable clinical basis. We postulated that we could reduce inappropriate testing and improve clinical laboratory stewardship by removing the TSH checkbox from the CCU admission order set.

METHODS

After we retrospectively evaluated CCU TSH ordering before intervention, the checkbox was removed from the CCU admission order set. Twelve weeks later, we commenced a prospective 2-month assessment of TSH testing and clinical sequelae of thyroid disease among all CCU admissions. If clinical indications were absent or testing had occurred within 6 weeks, TSH requests were labelled as 'inappropriate'.

RESULTS

Physician ordering and, specifically, inappropriate ordering decreased substantially after the intervention. In 2016 among physician-ordered TSH tests, 60.6% (66/109) were inappropriate; in 2017 this decreased to 20% (2/10, p=0.01). Overall, the net effect of checkbox removal saw the decrease in TSH testing without clinical indication outweigh an increase in missed testing where indications appear to exist.

CONCLUSIONS

Provision of an optional checkbox for a laboratory test in an admission order set can promote overuse of laboratory resources. Simple removal of a checkbox may dramatically change test ordering patterns and promote clinical laboratory stewardship. Given our reliance on order sets, particularly by trainees, changes to order sets must be cautious to assure guideline-directed care is maintained.

Interactions between hypothalamic pituitary thyroid axis and other pituitary dysfunctions

Central hypothyroidism is defined as low circulating free thyroxine (free T4) with inappropriately low circulating thyrotropin (TSH), in context of a hypothalamic pituitary pathology. Rare cases of idiopathic central hypothyroidism caused by a functional defect may occur, and the condition is often overlooked due to difficulty in achieving the correct diagnosis, sparse symptomatology of the condition and a high risk of misinterpretion of the biochemical changes in central hypothyroidism. Central hypothyroidism is mainly seen in patients with hypothalamic-pituitary pathology due to one of many possible aetiologies, where other hormone deficiencies often co-exist, and both the presence of other deficiencies and their replacement have a strong influence on the measurement of the thyroid-related hormones and thereby interpretation of the thyroid function variables in relation to the clinical impact of thyroid hormone substitution therapy. Conversely, lack of thyroid hormone has a similar strong influence on the interpretation of other pituitary hormone axes, as well as their replacement. Undertreating patients with central hypothyroidism may have serious metabolic consequences with a potentially increased risk of cardiovascular morbidity. The present review thus aims at describing central hypothyroidism, by an overview of interactions of hypothyroidism with other pituitary hormones, diagnosing/testing for central hypothyroidism, and focusing on consequences of undertreatment. Finally, it is mentioned how to deal with new diagnostic settings with lower a priori likelihood of hypopituitarism, particularly in view of the importance of stringent diagnostic testing in order to avoid overdiagnosing central hypothyroidism.