Dissociation of the early decline in serum T(3) concentration and serum IL-6 rise and TNFalpha in nonthyroidal illness syndrome induced by abdominal surgery

Prognostic role of euthyroid sick syndrome in MIS-C: results from a single-center observational study

Background

Euthyroid sick syndrome (ESS) is characterized by low serum levels of free triiodothyronine (fT3) with normal or low levels of thyroid stimulating hormone (TSH) and free thyroxine (fT4) and is reported in different acute clinical situations, such as sepsis, diabetic ketoacidosis and after cardiac surgery. Our aim was to evaluate the predicting role of ESS for disease severity in patients with Multisystem Inflammatory Syndrome in children (MIS-C).

Methods

A single-centre observational study on consecutive patients with MIS-C. Before treatment clinical, and laboratory data were collected and, in a subset of patients, thyroid function tests were repeated 4 weeks later. Variables distribution was analyzed by Mann-Whitney U-test and correlations between different parameters were calculated by Spearman's Rho coefficient.

Results

Forty-two patients were included and 36 (85.7%) presented ESS. fT3 values were significantly lower in patients requiring intensive care, a strong direct correlation was shown between fT3 and Hb, platelet count and ejection fraction values. A significant inverse correlation was retrieved between fT3 levels and C-reactive protein, brain natriuretic peptide, IL-2 soluble receptor and S-100 protein. Subjects with severe myocardial depression (EF < 45%) had lower fT3 values than subjects with higher EF. The thyroid function tests spontaneously normalized in all subjects who repeated measurement 4 weeks after admission.

Conclusion

ESS is a frequent and transient condition in acute phase of MIS-C. A severe reduction of fT3 must be considered as important prognostic factor for severe disease course, with subsequent relevant clinical impact in the management of these patients.

Wide Spectrum of Thyroid Function Tests in COVID-19: From Nonthyroidal Illness to Isolated Hyperthyroxinemia

BACKGROUND

Changes in thyroid function test (TFT) in COVID-19 patients have been reported in several studies. However, some features such as thyrotoxicosis are inconsistent in these studies. In addition, some drugs such as heparin interfere with the free T4 assay.

OBJECTIVES

This study was designed to examine TFT abnormalities in COVID-19, utilizing direct and indirect methods of free T4 assay.

METHODS

This prospective cross-sectional study was conducted on 131 hospitalized COVID-19 patients. Serum levels of total T3, TSH, T3RU, and total T4 were measured. The free T4 assay was performed using direct (free T4) and indirect (free thyroxin index or FT4I) methods. The patients were categorized into different TFT groups. The clinical characteristics, laboratory findings, and outcomes were compared between the groups.

RESULTS

The frequencies of nonthyroidal illness (NTI), subclinical/overt hypothyroidism and subclinical/overt thyrotoxicosis were 51.7, 6.9, and 6.9%, respectively. Besides, 6 and 8.1% of the patients had isolated high free T4 and isolated high FT4I without any other TFT abnormality, respectively. The lymphocyte percent was lower in the subclinical/overt group than in other TFT groups (P = 0.002). Atrial Fibrillation (AF) was found in 37.5% of subclinical/overt thyrotoxicosis patients versus 1.7% in the NTI and nil in the other three groups (P < 0.001).

CONCLUSIONS

In addition to the reported TFT abnormalities in COVID-19 in previous studies, some new features like isolated hyperthyroxinemia were found in our study. We found a strong association between subclinical/overt thyrotoxicosis and AF. Regarding the high prevalence of AF in hospitalized COVID-19 patients, request for thyroid function test is rational in COVID-19 patients with this arrhythmia.

Persisting neuroendocrine abnormalities and their association with physical impairment 5 years after critical illness

Background

Critical illness is hallmarked by neuroendocrine alterations throughout ICU stay. We investigated whether the neuroendocrine axes recover after ICU discharge and whether any residual abnormalities associate with physical functional impairments assessed 5 years after critical illness.

Methods

In this preplanned secondary analysis of the EPaNIC randomized controlled trial, we compared serum concentrations of hormones and binding proteins of the thyroid axis, the somatotropic axis and the adrenal axis in 436 adult patients who participated in the prospective 5-year clinical follow-up and who provided a blood sample with those in 50 demographically matched controls. We investigated independent associations between any long-term hormonal abnormalities and physical functional impairments (handgrip strength, 6-min walk distance, and physical health-related quality-of-life) with use of multivariable linear regression analyses.

Results

At 5-year follow-up, patients and controls had comparable serum concentrations of thyroid-stimulating hormone, thyroxine (T₄), triiodothyronine (T₃) and thyroxine-binding globulin, whereas patients had higher reverse T₃ (rT₃, p = 0.0002) and lower T₃/rT₃ (p = 0.0012) than controls. Patients had comparable concentrations of growth hormone, insulin-like growth factor-I (IGF-I) and IGF-binding protein 1 (IGFBP1), but higher IGFBP3 (p = 0.030) than controls. Total and free cortisol, cortisol-binding globulin and albumin concentrations were comparable for patients and controls. A lower T₃/rT₃ was independently associated with lower handgrip strength and shorter 6-min walk distance (p ≤ 0.036), and a higher IGFBP3 was independently associated with higher handgrip strength (p = 0.031).

Conclusions

Five years after ICU admission, most hormones and binding proteins of the thyroid, somatotropic and adrenal axes had recovered. The residual long-term abnormality within the thyroid axis was identified as risk factor for long-term physical impairment, whereas that within the somatotropic axis may be a compensatory protective response. Whether targeting of the residual abnormality in the thyroid axis may improve long-term physical outcome of the patients remains to be investigated.

Trial registration ClinicalTrials.gov: NCT00512122, registered on July 31, 2007 (https://www.clinicaltrials.gov/ct2/show/NCT00512122).

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03858-1.

Sepsis as a Pan-Endocrine Illness-Endocrine Disorders in Septic Patients

Sepsis is defined as "life-threatening organ dysfunction caused by a dysregulated host response to infection". One of the elements of dysregulated host response is an endocrine system disorder. Changes in its functioning in the course of sepsis affect almost all hormonal axes. In sepsis, a function disturbance of the hypothalamic-pituitary-adrenal axis has been described, in the range of which the most important seems to be hypercortisolemia in the acute phase. Imbalance in the hypothalamic-pituitary-thyroid axis is also described. The most typical manifestation is a triiodothyronine concentration decrease and reverse triiodothyronine concentration increase. In the somatotropic axis, a change in the secretion pattern of growth hormone and peripheral resistance to this hormone has been described. In the hypothalamic-pituitary-gonadal axis, the reduction in testosterone concentration in men and the stress-induced "hypothalamic amenorrhea" in women have been described. Catecholamine and β-adrenergic stimulation disorders have also been reported. Disorders in the endocrine system are part of the "dysregulated host response to infection". They may also affect other components of this dysregulated response, such as metabolism. Hormonal changes occurring in the course of sepsis require further research, not only in order to explore their potential significance in therapy, but also due to their promising prognostic value.

Thyroid hormone concentrations in severely or critically ill patients with COVID-19

OBJECTIVE

COVID-19 is a new coronavirus infectious disease. We aimed to study the characteristics of thyroid hormone levels in patients with COVID-19 and to explore whether thyroid hormone predicts all-cause mortality of severely or critically ill patients.

METHODS

The clinical data of 100 patients with COVID-19, who were admitted to Wuhan Tongji Hospital from February 8 to March 8, 2020, were analyzed in this retrospective study. The patients were followed up for 6-41 days. Patients were grouped into non-severe illness and severe or critical illness, which included survivors and non-survivors. Multivariate Cox proportional hazards analysis was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause mortality in association with continuous and the lower two quartiles of thyroid hormone concentrations in severely or critically ill patients.

RESULTS

The means of free T3 (FT3) were 4.40, 3.73 and 2.76 pmol/L in non-severely ill patients, survivors and non-survivors, respectively. The lower (versus upper) two quartiles of FT3 was associated with all-cause mortality HR (95% CI) of 9.23 (2.01, 42.28). The HR (95% CI) for all-cause mortality in association with continuous FT3 concentration was 0.41 (0.21, 0.81). In the multivariate-adjusted models, free T4 (FT4), TSH and FT3/FT4 were not significantly related to all-cause mortality. Patients with FT3 less than 3.10 pmol/L had increased all-cause mortality.

CONCLUSION

FT3 concentration was significantly lower in patients with severe COVID-19 than in non-severely ill patients. Reduced FT3 independently predicted all-cause mortality of patients with severe COVID-19.

Transient Hyperthyrotropinemia in Outpatient Children with Acute Infections of the Respiratory System

Background: Diagnostics of thyroid disorders (TD) are frequently based on the measurements of thyroid stimulating hormone (TSH) concentration only. If TSH is outside the reference range, the diagnostic procedure used in patients with TD isintroduced. Observations indicate that in a considerable number of these patients, TD is not confirmed. The aim of the study was to assess the incidence of transient hyperthyrotropinemia in healthy children during acute infections of the respiratory system. Patients and Methods: The study included consecutive children (49 boys and 45 girls), aged 2.2–17.3 years, who visited one General Practitioner (GP) due to respiratory tract infections. The tests: complete blood count (CBC), C-reactive protein (CRP), TSH and FT4 were run on the next day after the visit at the physician’s (initial visit) and ≥2 weeks after recovery. Results: Among these children, elevated TSH values were found in about 10% of patients, and they went back to normal values after recovery. A prospective analysis showed a reduction of TSH values in approx. 65% of all groups and TSH at the follow-up visit was significantly lower. Conclusions: Transient hyperthyrotropinemia was observed in about 10% of children with acute respiratory tract infection. This preliminary finding remains unexplained.

Incidence of low-triiodothyronine syndrome in patients with septic shock

OBJECTIVE

Low levels of thyroid hormones have been associated with poor clinical outcomes. This metabolic situation, designated euthyroid sick syndrome, has been interpreted as a state of adaptation to different pathological processes, characterized by the decrease in plasma triiodothyronine. The present study seeks to determine the incidence of this disorder in patients with septic shock and its relationship with other severity indices and clinical outcomes.

METHODS

This prospective analytical study evaluated patients admitted to the intensive care unit with septic shock between April 2018 and July 2019. Variables associated with septic shock and thyroid profile were recorded at the time of the septic shock diagnosis and 7, 14, and 21 days later.

RESULTS

A total of 27 patients who met the inclusion criteria were analyzed. The incidence of an altered thyroid axis was 96.3%, with a mortality at 28 days of 36.7%. Patients without hormonal alteration did not present negative outcomes. Among those with low triiodothyronine, 42.3% recovered their thyroid function within 28 days, in whom mortality was 0%; 57.7% did not recover their thyroid function, in whom mortality was 66.7%. Those whose thyroid axis was altered and who did not normalize its function required more doses of vasoactives and had deteriorated lactate clearance.

CONCLUSION

Patients with septic shock have a high incidence of alteration of the thyroid axis, and this dysfunction is associated with higher mortality.

Nonthyroidal Illness Syndrome Across the Ages

In conditions of acute illness, patients present with reduced plasma T3 concentrations without a concomitant rise in TSH. In contrast, plasma concentrations of the inactive hormone rT3 increase, whereas plasma concentrations of T4 remain low-normal. This constellation of changes, referred to as nonthyroidal illness syndrome (NTIS), is present across all ages, from preterm neonates and over-term critically ill infants and children to critically ill adults. Although the severity of illness strongly correlates with the severity of the NTIS phenotype, the causality of this association remains debated, and pathophysiological mechanisms remain incompletely understood. In the acute phase of illness, NTIS appears to be caused predominantly by an increased peripheral inactivation of thyroid hormones, in which reduced nutritional intake plays a role. Current evidence suggests that these acute peripheral changes are part of a beneficial adaptation of the body to reduce expenditure of energy and to activate the innate immune response, which is important for survival. In contrast, in more severely ill and prolonged critically ill patients, an additional central suppression of the thyroid hormone axis alters and further aggravates the NTIS phenotype. Recent studies suggest that this central suppression may not be adaptive. Whether treatment of this central component of NTIS in prolonged critically ill patients, with the use of hypothalamic releasing factors, improves outcome remains to be investigated in large randomized control trials.

Non-Thyroidal Illness Syndrome in Critically Ill Children: Prognostic Value and Impact of Nutritional Management

INTRODUCTION

Non-thyroidal illness (NTI), which occurs with fasting and in response to illness, is characterized by thyroid hormone inactivation with low triiodothyronine (T3) and high reverse T3 (rT3), followed by suppressed thyrotropin (TSH). Withholding supplemental parenteral nutrition early in pediatric critical illness (late-PN), thus accepting low/no macronutrient intake up to day 8 in the pediatric intensive care unit (PICU), accelerated recovery compared to initiating supplemental parenteral nutrition early (early-PN). Whether NTI is harmful or beneficial in pediatric critical illness and how it is affected by a macronutrient deficit remains unclear. This study investigated the prognostic value of NTI, the impact of late-PN on NTI, and whether such impact explains or counteracts the outcome benefit of late-PN in critically ill children.

METHODS

This preplanned secondary analysis of the Early versus Late Parenteral Nutrition in the Pediatric Intensive Care Unit randomized controlled trial quantified serum TSH, total thyroxine (T4), T3, and rT3 concentrations in 982 patients upon PICU admission versus 64 matched healthy children and in 772 propensity score-matched early-PN and late-PN patients upon admission and at day 3 or last PICU day for shorter PICU stay. Associations between thyroid hormone concentrations upon admission and outcome, as well as impact of late-PN on NTI in relation with outcome, were assessed with univariable analyses and multivariable logistic regression, linear regression, or Cox proportional hazard analysis, adjusted for baseline risk factors.

RESULTS

Upon PICU admission, critically ill children revealed lower TSH, T4, T3, and T3/rT3 and higher rT3 than healthy children (p < 0.0001). A more pronounced NTI upon admission, with low T4, T3, and T3/rT3 and high rT3 was associated with higher mortality and morbidity. Late-PN further reduced T4, T3, and T3/rT3 and increased rT3 (p ≤ 0.001). Statistically, the further lowering of T4 by late-PN reduced the outcome benefit (p < 0.0001), whereas the further lowering of T3/rT3 explained part of the outcome benefit of late-PN (p ≤ 0.004). This effect was greater for infants than for older children.

CONCLUSION

In critically ill children, the peripheral inactivation of thyroid hormone, characterized by a decrease in T3/rT3, which is further accentuated by low/no macronutrient intake, appears beneficial. In contrast, the central component of NTI attributable to suppressed TSH, evidenced by the decrease in T4, seems to be a harmful response to critical illness. Whether treating the central component with TSH releasing hormone infusion in the PICU is beneficial requires further investigation.

Relation of thyroid hormone abnormalities with subclinical inflammatory activity in patients with type 1 and type 2 diabetes mellitus

Thyroid hormone (TH) abnormalities are common in patients with diabetes mellitus (DM). These thyroid hormone abnormalities have been associated with inflammatory activity in several conditions but this link remains unclear in DM. We assessed the influence of subclinical inflammation in TH metabolism in euthyroid diabetic patients. Cross-sectional study involving 258 subjects divided in 4 groups: 70 patients with T2DM and 55 patients with T1DM and two control groups of 70 and 63 non-diabetic individuals, respectively. Groups were paired by age, sex, and body mass index (BMI). We evaluated the association between clinical and hormonal variables [thyrotropin, reverse T3 (rT3), total and free thyroxine (T4), and triiodothyronine (T3)] with the inflammation markers C-reactive protein (hs-CRP), serum amyloid A (SAA), and interleukin-6 (IL-6). Serum T3 and free T3 were lower in patients with diabetes (all P < 0.001) compared to the control groups. Interleukin-6 showed positive correlations with rT3 in both groups (P < 0.05). IL-6 was independently associated to FT3/rT3 (B = -0.193; 95% CI -0.31; -0.076; P = 0.002) and FT4/rT3 (B = -0.107; 95% CI -0.207; -0.006; P = 0.039) in the T1DM group. In the T2DM group, SAA (B = 0.18; 95% CI 0.089; 0.271; P < 0.001) and hs-CRP (B = -0.069; 95% CI -0.132; -0.007; P = 0.03) predicted FT3 levels. SAA (B = -0.16; 95% CI -0.26; -0.061; P = 0.002) and IL6 (B = 0.123; 95% CI 0.005; 0.241; P = 0.041) were related to FT4/FT3. In DM, differences in TH levels compared to non-diabetic individuals were related to increased subclinical inflammatory activity and BMI. Altered deiodinase activity was probably involved. These findings were independent of sex, age, BMI, and HbA1c levels.

Role of enteral nutrition in nonthyroidal illness syndrome: a retrospective observational study

BACKGROUND

The nonthyroidal illness syndrome (NTIS) is prevalent among patients with enterocutaneous fistula and is associated with poor outcomes. The present study aimed to explore the role of enteral nutrition (EN) therapy on thyroid function among patients with enterocutaneous fistula and NTIS.

METHODS

We conducted a retrospective observational study among patients with enterocutaneous fistula between January 2013 and April 2014. All enrolled patients received EN therapy. Thyroid function and other parameters were measured.

RESULTS

After administration of 4 weeks of EN therapy, NTIS was resolved in 66 patients (Group A), while it persisted in 14 patients (Group B). The overall treatment success rate was 82.50 %. There were no significant differences between groups A and B at baseline for all parameters, except for the time from admission to start of EN therapy. The logistic analysis revealed that the time from admission to start of EN therapy was a significant independent indicator for achieving resolution of NTIS in our cohort.

CONCLUSIONS

This retrospective observational cohort study demonstrated that EN therapy can aid in the resolution of NTIS among patients with enterocutaneous fistula. These findings confirm the benefit of EN in the treatment of enterocutaneous fistula.

Thyroid function in critically ill patients

Patients in the intensive care unit (ICU) typically present with decreased concentrations of plasma tri-iodothyronine, low thyroxine, and normal range or slightly decreased concentration of thyroid-stimulating hormone. This ensemble of changes is collectively known as non-thyroidal illness syndrome (NTIS). The extent of NTIS is associated with prognosis, but no proof exists for causality of this association. Initially, NTIS is a consequence of the acute phase response to systemic illness and macronutrient restriction, which might be beneficial. Pathogenesis of NTIS in long-term critical illness is more complex and includes suppression of hypothalamic thyrotropin-releasing hormone, accounting for persistently reduced secretion of thyroid-stimulating hormone despite low plasma thyroid hormone. In some cases distinguishing between NTIS and severe hypothyroidism, which is a rare primary cause for admission to the ICU, can be difficult. Infusion of hypothalamic-releasing factors can reactivate the thyroid axis in patients with NTIS, inducing an anabolic response. Whether this approach has a clinical benefit in terms of outcome is unknown. In this Series paper, we discuss diagnostic aspects, pathogenesis, and implications of NTIS as well as its distinction from severe, primary thyroid disorders in patients in the ICU.

The impact of tracheotomy on levels of procalcitonin in patients without sepsis: a prospective study

OBJECTIVE

Procalcitonin is a reliable biomarker of infection and sepsis. We aimed to determine whether tracheotomy influences the procalcitonin concentrations in patients without sepsis and assess whether operative duration and procedure affect the peak procalcitonin level.

METHODS

A total of 38 non-septic patients who required a tracheotomy underwent either a percutaneous dilatational tracheotomy (n=19) or a surgical tracheotomy (n=19). Procalcitonin levels were measured at the beginning of the tracheotomy and at 2 h, 4 h, 8 h, 24 h, 48 h and 72 h after the procedure.

RESULTS

The baseline procalcitonin concentration before the tracheotomy was 0.24 ± 0.13 ng/mL. The postoperative levels increased rapidly, with a 4-fold elevation after 2 h, reaching a peak 4 h later with a 5-fold increase over baseline. Thereafter, the levels gradually returned to 2-fold greater than the baseline level within 72 h. The peak levels of procalcitonin showed a significant positive correlation with operative durations (r=0.710, p<0.001) and procedures (rho=0.670, p<0.001).

CONCLUSION

In patients without sepsis, tracheotomy induces a rapid release of serum procalcitonin, and the operative duration and procedure have significant impacts on the peak procalcitonin levels. Thus, the nonspecific increase in procalcitonin levels following tracheotomy needs to be considered when this measure is used to evaluate infection.

Nonthyroidal illness syndrome in off-pump coronary artery bypass surger

OBJECTIVE

It is well known that coronary artery bypass grafting (CABG) is often the cause of non-thyroidal illness syndrome (NTIS). Non-thyroidal illness syndrome (NTIS) is a state characterized by low levels of tri-iodo-thyronine (T3) and high levels of reverse T3 (rT3), with normal or low levels of thyroxin (T4) and normal, low-normal, or low levels of thyroid-stimulating hormone (TSH). Today, there are two main techniques of CABG: CABG with the use of cardiopulmonary bypass (on-pump coronary artery bypass - ONCAB) and CABG without the use of cardiopulmonary bypass (off-pump coronary artery bypass OPCAB), or 'beating-heart surgery.' The OPCAB technique is considered to be less invasive. We prospectively investigated the influence of these surgical techniques on the occurrence of NTIS.

METHODS

Serum levels of free fractions of thyroid hormones (FT3 and FT4) and TSH were analyzed in 70 consecutive patients subjected to CABG surgery, using the ONCAB technique in 36 patients and OPCAB technique in 34 patients. The measurements of hormone levels were performed prior to surgery and 12 hours and 14 days after surgery.

RESULTS

The basic, the early, and the late postoperative serum levels of FT3 (p=0.458, p=0.632, p=0.869, respectively), FT4 (p=0.664, p=0.301, p=0.417, respectively), and TSH (p=0.249, p=0.058, p=0.324, respectively) were similar in both groups. The levels of FT3 and TSH were significantly lower 12 hours after surgery (p<0.0001, p<0.0001, respectively), and the FT4 levels rose at the same time (p<0.0001). The third measurement showed the return of all investigated parameters back to physiological levels, although they were still not precisely within the initial values.

CONCLUSION

NTIS occurs significantly in patients subjected to CABG. Although the OPCAB technique is considered to be less invasive, its impact on the occurrence of NTIS does not differ significantly from the ONCAB technique.

Non-thyroidal illness in the ICU: a syndrome with different faces

BACKGROUND

Critically ill patients typically present with low or low-normal plasma thyroxine, low plasma triiodothyronine (T3), increased plasma reverse T3 (rT3) concentrations, in the absence of a rise in thyrotropin (TSH). This constellation is referred to as nonthyroidal illness syndrome (NTI). Although it is long known that the severity of NTI is associated with risk of poor outcomes of critical illness, the causality in this association has not been well investigated.

SUMMARY

In this narrative review, the different faces of NTI during critical illness are highlighted. Acute alterations are dominated by changes in thyroid hormone binding, peripheral thyroid hormone uptake, and alterations in the expression and activity of the type-1 and type-3 deiodinases. It was recently shown that at least part of these acute changes are brought about by concomitant macronutrient restriction, and this part appears adaptive and beneficial. However, the face of the NTI in the prolonged phase of critical illness is different, when patients are fully fed but continue to depend on intensive medical care. In that prolonged phase of illness, hypothalamic thyrotropin releasing hormone (TRH) expression is suppressed and explains reduced TSH secretion and whereby reduced thyroidal hormone release. During prolonged critical illness, and in the presence of adequate nutrition, several tissue responses could be interpreted as compensatory to low thyroid hormone availability, such as increased expression of monocarboxylate transporters, upregulation of type-2 deiodinase activity, and increased sensitivity at the receptor level. Infusing hypothalamic releasing factors in these prolonged critically ill patients can reactivate the thyroid axis and induce an anabolic response.

CONCLUSIONS

It is clear that the name "NTI" during critical illness refers to a syndrome with different faces. Tolerating the early "fasting response" to critical illness and its concomitant changes in thyroid hormone parameters appears to be wise and beneficial. This thus applies to the NTI present in the majority of the patients treated in intensive care units. However, the NTI that occurs in prolonged critically ill patients appears different with regard to both its causes and consequences. Future studies should specifically target this selected population of prolonged critically ill patients, and, after excluding iatrogic drug interferences, investigate the effect on outcome of treatment with hypothalamic releasing factors in adequately powered randomized controlled trials.

Thyroid hormones and antioxidant systems: focus on oxidative stress in cardiovascular and pulmonary diseases

In previous works we demonstrated an inverse correlation between plasma Coenzyme Q₁₀ (CoQ₁₀) and thyroid hormones; in fact, CoQ₁₀ levels in hyperthyroid patients were found among the lowest detected in human diseases. On the contrary, CoQ₁₀ is elevated in hypothyroid subjects, also in subclinical conditions, suggesting the usefulness of this index in assessing metabolic status in thyroid disorders. A Low-T3 syndrome is a condition observed in several chronic diseases: it is considered an adaptation mechanism, where there is a reduction in pro-hormone T4 conversion. Low T3-Syndrome is not usually considered to be corrected with replacement therapy. We review the role of thyroid hormones in regulation of antioxidant systems, also presenting data on total antioxidant capacity and Coenzyme Q₁₀. Published studies suggest that oxidative stress could be involved in the clinical course of different heart diseases; our data could support the rationale of replacement therapy in low-T3 conditions.

Comparison of the Effects of Remifentanil and Dexmedetomidine Infusions on Hemodynamic Parameters and Thyroid Hormones

OBJECTIVE

In this study, we compared the effects of remifentanil and dexmedetomidine on hemodynamic parameters, inhalation agent consumption and thyroid hormone levels at the late postoperative period.

METHODS

Forty-five euthyroid ASA I-II patients between 20 and 75 years of age were randomly assigned into three groups: During induction, Group R received 1.0 mcg kg(-1) remifentanil as slow bolus in two minutes,Group D received 1.0 mcg kg(-1) dexmedetomidine in 10 minutes as infusion,Group C received 1.0 mcg kg(-1) fentanyl as bolus. Afterwards, all patients received 2.0 mg kg(-1) propofol and 0.2 mg kg(-1) cisatracurium for induction.For anaesthesia maintenance during and up to 15 minutes before the end of the surgery; Group R received 0.05 mcg kg(-1) min(-1) remifentanil,Group D received 0.5 mcg kg(-1) h(-1) dexmedetomidine infusion.During the surgery, heart rate, mean arterial pressure and end-tidal sevoflurane concentrations were recorded for every patient. Venous blood samples were taken after the operation, at postoperative 24(th) hour and postoperative 5(th) day and the variations in fT3, fT4, TSH levels were analyzed.

RESULTS

Mean arterial pressure values and sevoflurane consumption were lower in Group R and Group D in comparison with the control group. In comparison between groups, the decrease in fT3 values at postoperative 24(th) hour was more significant in the control group than the other two groups.

CONCLUSION

We suggest that, both agents suppress the hemodynamic response, decrease the consumption of inhalation agents and cause less change in the levels of thyroid hormones, which can be considered as one of the indicators of endocrine response.

The influence of liver and pancreas surgery on the thyroid function

Background

Nowadays, the increasing number of oncologic patients with liver or pancreatic tumours are subjected to surgical treatment, as it can provide a long-term survival or sometimes cure. As a result, numerous new clinical questions regarding metabolic disturbances in these patients have been arisen. Among others, the impact of the pancreas and liver surgery extent in relation to the thyroid function remains to be elucidated.

Materials and methods

The study comprised 51 patients (25 men and 26 women, mean age ± SD 61.6 ± 10.4 yrs, mean ± SD) with pancreatic or liver tumours, qualified for abdominal operation. Serum levels of FT3, FT4 and TSH were measured on the day before (time “0”) and on the 1^st, 3^rd and 5^th day after surgery in two (2) subgroups reflecting the extent of surgery: twenty seven (27) patients (14 men and 13 women, mean age ± SD 61.5 ± 11.8 yrs) after major surgery (Whipple’s surgery, right and left hemihepatectomy, segmentectomy of the liver, distal pancreatectomy, total duodenopancreatectomy) and twenty four (24) patients (11 men and 13 women, mean age ± SD 61.8 ± 8.9 yrs) after minor, palliative surgery (exploratory laparotomy, gastroenterostomy, triple by-pass, liver tumour embolization, hepaticojejunostomy). Additionally, the obtained results were analyzed in relation to the type of the disease (pancreatic surgery vs liver surgery).

Results

Mean serum FT3 level decreased significantly during the study in major and minor surgery subgroups (p<0.001, in both) in comparison to the baseline values, accompanied by stable serum concentrations of TSH (NS) and FT4 (NS). The above decreasing tendency in FT3 concentrations was similar in both subgroups (NS), the same as were unchanged levels of TSH (NS) and FT4 (NS). Mean FT4 concentration on the 3^rd and 5^th day after major surgery was lower in pancreatic tumour patients in comparison to liver tumour patients (p=0.002, p=0.032, respectively). Similarly, mean FT3 concentration on the 3^rd day in minor surgery subgroup was lower in pancreatic tumour patients in comparison to liver tumour patients (p=0.015).

Discussion

Our findings have confirmed essential reduction of FT3 values after abdominal surgery, independently of surgery extent. Additionally, pancreatic tumour patients are more likely to have lower FT3 and FT4 levels after surgery when compared to liver tumour patients.

Clinical review: thyroid hormone replacement in children after cardiac surgery--is it worth a try?

Cardiac surgery using cardiopulmonary bypass produces a generalized systemic inflammatory response, resulting in increased postoperative morbidity and mortality. Under these circumstances, a typical pattern of thyroid abnormalities is seen in the absence of primary disease, defined as sick euthyroid syndrome (SES). The presence of postoperative SES mainly in small children and neonates exposed to long bypass times and the pharmacological profile of thyroid hormones and their effects on the cardiovascular physiology make supplementation therapy an attractive treatment option to improve postoperative morbidity and mortality. Many studies have been performed with conflicting results. In this article, we review the important literature on the development of SES in paediatric postoperative cardiac patients, analyse the existing information on thyroid hormone replacement therapy in this patient group and try to summarize the findings for a recommendation.

Thyroid function and outcome in children who survived meningococcal septic shock

OBJECTIVE

To investigate the time course of thyroid function, factors that affect it, and its relationship to outcome in children surviving meningococcal septic shock.

DESIGN AND SETTING

Observational cohort study in a university-affiliated pediatric intensive care unit (PICU).

PATIENTS AND PARTICIPANTS

We divided the 44 children admitted to the PICU who survived meningococcal septic shock into those with short-stay (<7 days, n=33) or long-stay (>or=7 days, n=11).

MEASUREMENTS AND RESULTS

Serum thyroid hormone concentrations were determined on PICU admission and after 24 and 48 h. The Pediatric Risk of Mortality score and selected laboratory parameters were used to assess disease severity. On admission all children showed signs of euthyroid sick syndrome: low total triiodothyronine (TT3) and high reverse triiodothyronine (rT3) without compensatory elevated thyrotropin (TSH). Admission rT3 levels and the TT3/rT3 ratio were correlated with C-reactive protein levels and with time from first petechia to admission. Short-stay children only had higher TT3 and lower interleukin 6 levels at admission than long-stay children; after 48 h they showed higher total thyroxin, free thyroxin, TT3, and TSH and lower rT3 than long-stay children. All changes in thyroid parameters within the first 24 h were related to length of PICU stay. In children receiving dopamine TSH levels and TT3/rT3 ratios remained unchanged, whereas both values increased in those who did not receive dopamine or in whom dopamine was discontinued.

CONCLUSIONS

All children surviving meningococcal septic shock showed signs of euthyroid sick syndrome on admission. Thyroid hormone level changes in the first 24 h were prognostic for length of PICU stay.