Impairment of Thyroid Function in Critically Ill Patients in the Intensive Care Units

Low T3 vs low T3T4 euthyroid sick syndrome in septic shock patients: A prospective observational cohort study

BACKGROUND

Both phases of euthyroid sick syndrome (ESS) are associated with worse prognosis in septic shock patients. Although there are still no indications for supplementation therapy, there is no evidence that both phases (initial and prolonged) are adaptive or that only prolonged is maladaptive and requires supplementation.

AIM

To analyze clinical, hemodynamic and laboratory differences in two groups of septic shock patients with ESS.

METHODS

A total of 47 septic shock patients with ESS were divided according to values of their thyroid hormones into low T3 and low T3T4 groups. The analysis included demographic data, mortality scores, intensive care unit stay, mechanical ventilation length and 28-day survival and laboratory with hemodynamics.

RESULTS

The Simplified Acute Physiology Score II score (P = 0.029), dobutamine (P = 0.003) and epinephrine requirement (P = 0.000) and the incidence of renal failure and multiple organ failure (MOF) (P = 0.000) were significantly higher for the low T3T4. Hypoalbuminemia (P = 0.047), neutrophilia (P = 0.038), lymphopenia (P = 0.013) and lactatemia (P = 0.013) were more pronounced on T2 for the low T3T4 group compared to the low T3 group. Diastolic blood pressure at T0 (P = 0.017) and T1 (P = 0.007), as well as mean arterial pressure at T0 (P = 0.037) and T2 (P = 0.033) was higher for the low T3 group.

CONCLUSION

The low T3T4 population is associated with higher frequency of renal insufficiency and MOF, with worse laboratory and hemodynamic parameters. These findings suggest potentially maladaptive changes in the chronic phase of septic shock.

Profound postinduction hypotension precipitated by immune checkpoint inhibitors: a case report

BACKGROUND

With the increasing use of immune checkpoint inhibitors (ICIs) in cancer therapy, perioperative healthcare professionals need to be vigilant about potential immune-related adverse events (irAEs). We report a case of severe postinduction hypotension in a patient undergoing laparotomy due to suspected intraabdominal bleeding from gastric cancer and Krukenberg tumors, caused by unrecognized hypothyroidism precipitated by ICIs.

CASE PRESENTATION

A 65-year-old Chinese female with a history of gastric adenocarcinoma and Krukenberg tumors, previously treated with nivolumab, presented to the emergency room with abdominal pain and hypotension. Despite ruling out other causes, including hypovolemia and anaphylaxis, her hypotension persisted. The patient was found to have severe hypothyroidism, likely an irAE from the use of nivolumab. Thyroxine replacement therapy resolved the hypotension, and the patient recovered uneventfully after surgery.

CONCLUSIONS

This case underscores the importance of considering irAEs, such as hypothyroidism, in patients treated with ICIs. Perioperative healthcare providers must remain vigilant for potential complications and promptly recognize and manage irAEs to optimize patient outcomes.

Prognostic significance of thyroid hormone T3 in patients with septic shock: a retrospective cohort study

Background

The role of thyroid hormones is crucial in the response to stress and critical illness, which has been reported to be closely associated with a poor prognosis in patients admitted to the intensive care unit (ICU). This study aimed to explore the relationship between thyroid hormone and prognosis in septic shock patients.

Methods

A total of 186 patients with septic shock were enrolled in the analytical study between December 2014 and September 2022. The baseline variables and thyroid hormone were collected. The patients were divided into survivor group and non-survivor group according to whether they died during the ICU hospitalization. Among 186 patients with septic shock, 123 (66.13%) were in the survivor group and 63 (33.87%) were in the non-survivor group.

Results

There were significant differences in the indictors of free triiodothyronine (FT3) (p = 0.000), triiodothyronine (T3) (p = 0.000), T3/FT3 (p = 0.000), acute physiology and chronic health evaluation II score (APACHE II) (p = 0.000), sequential organ failure assessment score (SOFA) (p = 0.000), pulse rate (p = 0.020), creatinine (p = 0.008), PaO2/FiO2 (p = 0.000), length of stay (p = 0.000) and hospitalization expenses (p = 0.000) in ICU between the two groups. FT3 [odds ratio (OR): 1.062, 95% confidence interval(CI): (0.021, 0.447), p = 0.003], T3 (OR: 0.291, 95% CI: 0.172-0.975, p = 0.037) and T3/FT3 (OR: 0.985, 95% CI:0.974-0.996, p = 0.006) were independent risk factors of the short-term prognosis of septic shock patients after adjustment. The areas under the receiver operating characteristic curves for T3 was associated with ICU mortality (AUC = 0.796, p < 0.05) and was higher than that for FT3 (AUC = 0.670, p < 0.05) and T3/FT3 (AUC = 0.712, p < 0.05). A Kaplan-Meier curve showed that patients with T3 greater than 0.48 nmol/L had a significantly higher survival rate than the patients with T3 less than 0.48 nmol/L.

Conclusions

The decrease in serum level of T3 in patients with septic shock is associated with ICU mortality. Early detection of serum T3 level could help clinicians to identify septic shock patients at high risk of clinical deterioration.

A Role of Thyroid Hormones in Acute Myocardial Infarction: An Update

The acute coronary syndrome is one of the commonest life-threatening illnesses. It encompasses the clinical spectrum of acute myocardial ischemia and includes unstable angina and acute myocardial infarction both with and without ST segment elevation. The acute coronary syndrome can be attributed to a significant hemodynamic insult that leads to atherosclerosis of the epicardial coronary arteries. The main causative risk factors, such as obesity, smoking, and alcohol intake, increase the burden of acute coronary syndrome. Owing to an increase in the utilization of antioxidants, the antioxidant capacity decreases concerning the scavenging of lipid peroxides. Moreover, the thyroid hormones are important regulators of the expression of cardiac genes, and many of the cardiac manifestations of thyroid dysfunction are associated with alterations in triiodothyronine- mediated gene expression. Cardiovascular signs and symptoms of thyroid disease are among the most acute clinically relevant findings that occur in combination with both hypothyroidism and hyperthyroidism. By understanding the cellular mechanism of the action of thyroid hormones on the heart and cardiovascular system, it is possible to explain rhythm disturbances and alterations in cardiac output, blood pressure, cardiac contractility, and vascular resistance that result from thyroid dysfunction. Oxidative stress is thereby induced, together with a decrease in antioxidant capacity for overcoming oxidative stress, which leads to endothelial dysfunction, subsequent atherosclerosis, and, ultimately, acute myocardial infarction. The implications for the identification of the effects of thyroid disease on acute myocardial infarction include the observation that restoration of normal thyroid function repeatedly reverses abnormalities in cardiovascular hemodynamics.

Decreased triiodothyronine (T3) as a predictor for prolonged mechanical ventilation in critically ill patients with cardiac surgery

BACKGROUND

This study aimed to examine the correlation between thyroid hormone and prolonged mechanical ventilation (MV) in adult critically ill patients having undergone cardiac surgery.

METHODS

The present study refers to a retrospective, cohort study conducted at Nanjing First Hospital from March 2019 to December 2020. Patients receiving cardiac surgery and admitting to the Cardiovascular Intensive Care Unit (CVICU) in the study period were screened for potential inclusion. Demographic information, thyroid hormone and other laboratory measurements and outcome variables were recorded for analysis. Prolonged MV was defined as the duration of MV after cardiac surgery longer than 5 days. Thyroid hormones were assessed for the prognostic significance for prolonged MV.

RESULTS

One thousand eight hundred ninety-six patients who underwent cardiac surgery were screened for potential enrollment. Overall, 118 patients were included and analyzed in this study. Patients fell to the control (n = 64) and the prolonged MV group (n = 54) by complying with the duration of MV after cardiac surgery. The median value of total triiodothyronine (TT3) and free triiodothyronine (FT3) were 1.03 nmol/L and 3.52 pmol/L in the prolonged MV group before cardiac surgery, significantly lower than 1.23 nmol/L (P = 0.005) and 3.87 pmol/L, respectively in control (P = 0.038). Multivariate logistic regression analysis indicated that TT3 before surgery (pre-op TT3) had an excellent prognostic significance for prolonged MV (OR: 0.049, P = 0.012).

CONCLUSIONS

This study concluded that decreased triiodothyronine (T3) could be common in cardiac patients with prolonged MV, and it would be further reduced after patients undergo cardiac surgery. Besides, decreased T3 before surgery could act as an effective predictor for prolonged MV after cardiac surgery.

Low Triiodothyronine Syndrome Increased the Incidence of Acute Kidney Injury After Cardiac Surgery

Background

Acute kidney injury (AKI) is a severe complication of cardiac surgery. This study was designed to explore the association between the preoperative low T3 syndrome and cardiac surgery-associated acute kidney injury (CSA-AKI).

Methods

This was a retrospective single-center study. Data on 784 patients undergoing elective coronary artery bypass grafting (CABG) or valve surgery were collected from January 2016 to July 2019. AKI was defined according to Kidney Disease: Improving Global Outcomes guidelines. The effect of preoperative low T3 syndrome (fT3 < 3.5pmol/L) on the risk of the postoperative AKI was analyzed in a logistic regression model.

Results

There were 171 (21.8%) patients developing AKI. Preoperative T3 and FT3 levels were lower in patients with AKI than in those without AKI (P < 0.001). The incidence of postoperative AKI was higher in patients with low T3 syndrome than in those without (31.0% vs 19.8%; P = 0.003). Multivariate logistic regression analysis showed that low T3 syndrome was an independent risk factor for CSA-AKI patients (OR = 1.609, 95% CI: 1.033–2.504; P = 0.035), after adjusting for confounding factors, such as age, albumin, and uric acid. Subgroup analyses showed that preoperative low T3 syndrome also increased incidence of CSA-AKI in those with high risk factors, such as age ≧60 yrs (OR: 1.891, 95% CI: 1.183–3.022, P = 0.008), hypertension (OR: 2.104, 95% CI: 1.218–3.3.635, P = 0.008), and hyperuricemia (OR: 2.052, 95% CI: 1.037–4.06, P = 0.039).

Conclusion

Low T3 syndrome independently increases the risk of CSA-AKI. Patients with low T3 syndrome should be considered at higher risk and be evaluated before cardiac surgery.

Serum total triiodothyronine (T3) as a predictor of mortality and morbidity in critically ill patients and its correlation of predictability with acute physiology and chronic health evaluation II score: A prospective observational study

Background:

The aim is to assess the prognostic value of total T3, total T4, and thyroid-stimulating hormone among critically ill patients admitted to the medical intensive care unit (ICU) in association with mortality and its correlation with the acute physiology and chronic health evaluation II (APACHE II) score.

METHODS

: Our prospective observational study consists of 257 patients without known thyroid diseases admitted to the medical ICU. The baseline characteristics of the patients were recorded, including the APACHE II score and thyroid hormone levels at ICU admission. Based on the primary outcome of mortality, we analyzed the data by appropriate statistical methods. A P < 0.05 was considered significant.

Results:

Of the 257 patients included in the study, 47 (18.28%) succumbed to their illnesses. A significant difference in T3 levels (P < 0.001), T4 levels (P < 0.001), and APACHE II score (P < 0.001) was found between the survivors and the nonsurvivors. There was negative correlation observed between T3 and APACHE II score (r = −0.448, P < 0.001) and T4 and APACHE II score (r = −0.221, P ≤ 0.001). Multivariate logistic regression analysis determined T3 to be the only independent predictor of ICU mortality among thyroid hormones. The area under the curve (AUC) for T3 (0.811 ± 0.04) was almost equal to that of the APACHE II score (0.858 ± 0.029). The duration of ICU stay and hospital stay in patients with low T3 was significantly higher compared to patients with normal T3.

Conclusion:

Serum T3 is a good indicator for predicting mortality and morbidity among critically ill patients.

Thyroid hormone disorders: a predictor of mortality in patients with septic shock defined by Sepsis-3?

Decreased serum thyroid hormone levels and their prediction of mortality in septic patients are still controversial, especially with the evolution of the definition of sepsis. This study aimed to assess the ability of thyroid hormone disorders to predict the early mortality of patients with septic shock defined by Sepsis-3. Sixty-three adult patients with septic shock admitted to a university hospital emergency intensive care unit (EICU) were studied. Serum free T3 (FT3), free T4 (FT4), thyroid stimulating hormone (TSH), C-reactive protein (CRP), procalcitonin (PCT), and lactate levels were determined and compared with survival status and organ dysfunction. Among the 63 patients studied, lower serum FT3 and FT4 levels were significantly associated with higher sequential organ failure assessment (SOFA) scores. Patients with septic shock with lower levels of FT3 (≤ 1.70 pmol/L) and FT4 (≤ 9.99 pmol/L) had significantly increased 28-day mortality. There was no significant difference in the serum TSH level between the survivor and nonsurvivor groups. The areas under the receiver operating characteristic curves for FT3 and FT4 levels were associated with 28-day mortality (0.92 and 0.89, respectively) and were higher than that for SOFA (0.82), CRP (0.65) and lactate (0.59). The decrease in serum levels of FT3 and FT4 in patients with septic shock is associated with the severity of organ dysfunction and 28-day mortality. Early detection of serum FT3 and FT4 levels could help clinicians to identify patients at high risk of clinical deterioration.

The Stability of TSH, and Thyroid Hormones, in Patients Treated With Tablet, or Liquid Levo-Thyroxine

Approximately, 5% of the population is affected by hypothyroidism, mainly women and persons aged more than 60 years. After the diagnosis of hypothyroidism the usual therapy is tablet levothyroxine (L-T4), with a monitoring of the thyroid-stimulating hormone (TSH) level in primary hypothyroidism every 6-8 weeks and L-T4 is adjusted as necessary to reach an euthyroid state. Once TSH is stabilized in the normal range, it is recommended to conduct annual testing in the treated subjects to warrant suitable replacement. More recently advances regarding L-T4 treatment are the introduction of new oral formulations: the liquid solution, and soft gel capsule. The soft gel capsule permits a quick dissolution in the acid gastric pH. The liquid preparation does not require an acid gastric environment. Many pharmacokinetic studies demonstrated a more rapid absorption for the liquid L-T4, or capsule, than with tablet. Many studies have shown that the liquid, or capsule, formulations can overcome the interaction with foods, drugs or malabsorptive conditions, that are able to impair the tablet L-T4 absorption. Lately studies have suggested that liquid L-T4 can permit to maintain more efficiently normal TSH levels in hypothyroid patients in the long-term follow-up, than tablet L-T4, both in patients with malabsorptive states, and in those without malabsorption. Further large, prospective, longitudinal studies are needed to evaluate the stability of TSH, in hypothyroid patients treated with different L-T4 formulations.

Serum thyroxine and thyrotropin concentrations decrease with severity of nonthyroidal illness in cats and predict 30-day survival outcome

Background

In cats, nonthyroidal illness affects serum thyroid hormone concentrations. Serum thyroxine (T₄) and triiodothyronine (T₃) concentrations commonly decrease, whereas free T₄ (fT₄) concentrations vary unpredictably. Limited information exists regarding effects on serum thyrotropin (thyroid‐stimulating hormone [TSH]) concentrations in cats with nonthyroidal illness syndrome (NTIS).

Objectives

To characterize alterations in thyroid function that develop in cats with NTIS and to correlate these alterations with severity and outcome of the nonthyroidal illness.

Animals

Two hundred and twenty‐two cats with NTIS and 380 clinically normal cats of similar age and sex.

Methods

Prospective, cross‐sectional study. All cats had serum T₄, T₃, free T₄, and TSH concentrations measured. Cats were grouped based on illness severity and 30‐day survival.

Results

Cats with NTIS had lower serum T₄ and T₃ concentrations than did normal cats (P < .001). Serum fT₄ and TSH concentrations did not differ between groups. Serum T₄, T₃, and fT₄ concentrations progressively decreased with increasing disease severity (P < .001). The 56 cats that died had lower T₄, T₃, and TSH concentrations than did the 166 survivors, with no difference in fT₄ concentration. Multivariable logistic regression modeling indicated that serum T₄ and TSH concentrations both predicted survival (P < .02).

Conclusions and Clinical Importance

Cats with NTIS commonly develop low serum T₄, T₃, and TSH concentrations, the prevalence and extent of which increases with disease severity. Clinicians should consider evaluating thyroid function in cats with severe NTIS, because doing so could help determine probability of successful treatment responses before investing considerable time, effort, and finances in addressing the underlying disease.

Myxedema coma precipitated by diabetic ketoacidosis after total thyroidectomy: a case report

BACKGROUND

Myxedema coma is profound decompensated hypothyroidism usually precipitated by stressors, and its occurrence in association with total thyroidectomy or metabolic disorders, such as diabetic ketoacidosis, is unusual.

CASE PRESENTATION

A 43-year-old Asian man with history of total thyroidectomy who was scheduled for a second radioactive iodine therapy presented to our hospital with decreased mental status and hyperglycemia. He had a history of thyroid cancer but did not have diabetes mellitus. He was in a hypothermic state and had a Glasgow Coma Scale score of 10 out of 15 at presentation; arterial blood gas analysis revealed a state of metabolic acidosis and laboratory findings suggested hyperglycemia with glycosuria, ketoacidosis, and severe hypothyroidism. A thyroid function test showed thyroid-stimulating hormone of 34.126 uIU/mL, free thyroxine of 1.02 ng/dL, and triiodothyronine of 1.04 ng/mL. The glycated hemoglobin of this patient was checked due to hyperglycemia and the value of glycated hemoglobin was 16.5% which met the criteria for a diagnosis of diabetes. After treatment for myxedema with liothyronine 5 mcg two times per day and levothyroxine 175 mcg once daily via a nasogastric tube and diabetic ketoacidosis with intravenously administered fluid and insulin, his clinical condition rapidly improved including mental status, hyperglycemia, and acidosis. During the hospitalization, a workup for diabetes mellitus was performed and the results suggested that a diagnosis of type 2 diabetes mellitus would be appropriate.

CONCLUSIONS

This case demonstrated that diabetic ketoacidosis not only could be a potential contributor to myxedema coma but also mask typical clinical features, making diagnosis more difficult. Considering the possibility of an increasing number of potential patients with hypothyroidism developed after thyroidectomy, constant vigilance is required for a better clinical outcome, including early recognition and management in critical care in advance for unusual diabetic ketoacidosis which could precipitate decompensated hypothyroidism.