Low triiodothyronine serum levels as a predictor of poor prognosis in burn patients

OBJECTIVE: Euthyroid sick syndrome is a common finding in critically ill patients with nonthyroidal illness, characterized by low serum levels of free triiodothyronine (fT3) with a peculiar increase in reverse T3 (rT3) and normal-to-low free thyroxine (fT4) as well as thyroid-stimulating hormone (TSH) levels. This condition has been proposed as a prognostic factor of worse outcome in critically ill patients, while no conclusive data are available in burns. METHODS: Since thyroid function testing is contained in our baseline laboratory tests at admission, we retrospectively evaluated fT3, fT4 and TSH in 295 consecutive burn patients admitted to the Burn Center of Turin from January 2002 to December 2006, comparing hormone levels in survivors and non-survivors. RESULTS: fT3 and TSH levels were significantly lower (p相似文献   

A longitudinal evaluation of thyroid function in critically ill surgical patients.

Thyroid hormone alterations (known as the "sick-euthyroid syndrome") are common following major surgery, but the time course for appearance and recovery from these alterations has not previously been longitudinally studied in a large group of surgical patients. The authors prospectively studied 59 patients undergoing major surgery (coronary artery bypass grafting, pneumonectomy, or subtotal colectomy). Compared with preoperative values, the mean serum T4, T3, free T3, and TSH concentrations decreased significantly (p less than 0.05) following surgery. Serum reverse T3 and T3 resin uptake index increased, while free T4 levels remained unchanged. These changes were seen within 6 hours of surgery and normalized by 1 week after surgery. Although the serum TSH response to TRH was normal before and after surgery in 56 of the 59 patients, the maximal TRH-induced increase in serum TSH and the integrated serum TSH response to TRH were suppressed in the early perioperative period. This postoperative TSH suppression correlated with elevated postoperative plasma dopamine concentrations (r = 0.57, p less than 0.05). Three patients with compensated primary hypothyroidism were detected in the study and represent the first documentation of serial thyroid hormone and TSH levels in hypothyroid patients undergoing major surgery. These patients had similar changes in thyroid hormone values compared with euthyroid patients. The serum TSH response to TRH was suppressed into the normal range in two of these patients on the day following surgery. The authors conclude that the sick-euthyroid syndrome occurs within a few hours of major surgery and remits with convalescence. Postoperative decreases in serum TSH may mask the diagnosis of hypothyroidism. Surgical consultants should be aware of these rapid postoperative changes so that thyroid function tests are properly interpreted in patients who have undergone major surgery.     

Nonthyroidal illness syndrome in off-pump coronary artery bypass grafting

BACKGROUND: Cardiopulmonary bypass (CPB) is an established cause of nonthyroidal illness syndrome (NTIS). Off-pump coronary artery bypass (OPCAB) has been reported to be less invasive than coronary artery bypass grafting (CABG) with CPB. We prospectively evaluated thyroid metabolism in OPCAB patients. METHODS: We analyzed free thyroid hormones (FT3 and FT4), thyroid-stimulating hormone (TSH), and reverse T3 (rT3) in 20 consecutive patients undergoing CABG surgery. Nine patients underwent CABG with CPB, and 11 underwent OPCAB. Blood samples were taken on admission, on the day of surgery (7:30 AM), after sternotomy, at the end of the operation, and at 2, 6, 12, 24, 36, 48, 72, 96, 120, and 144 hours postoperatively. The concentrations of FT3, FT4, and TSH were determined on each sample. Reverse T3 concentration was measured in 10 patients up to 48 hours and at 144 hours postoperatively. RESULTS: Baseline, operative, and postoperative variables were similar in the two groups. FT3 concentration dropped significantly (p < 0.0001), reaching its lowest value 12 hours postoperatively. There were no significant differences between CPB and OPCAB patients. FT4 varied significantly in both groups (p < 0.0001), but remained in the normal range. TSH variation was not significant. rT3 concentration rose significantly (p = 0.0002) in both groups, peaking 24 hours after surgery. CONCLUSIONS. OPCAB induces a NTIS similar to that observed after CPB, probably due to the inhibition of T4 conversion to T3. This finding suggests that NTIS is a nonspecific response to stress. CPB should not be considered as the sole trigger of NTIS in cardiac surgical patients.     

Alterations of thyroid hormone indices in acute renal failure and in acute critical illness with and without acute renal failure

The present study evaluated thyroid hormone indices of patients with acute renal failure without other systemic illnesses (n = 12), as compared to patients with critical illnesses in the presence (n = 16) and absence (n = 6) of acute renal failure. Abnormalities in the group with acute renal failure alone included decreased serum levels of total T4 and T3, and elevated levels of free rT3. Serum levels of free T4 by equilibrium dialysis and the enzyme immunoassay, T3 uptake ratios, TSH and total rT3 were normal. These findings are consistent with the presence of decreased binding of T4 and rT3 to their serum carrier proteins. Critically ill patients with acute renal failure differed in that they had lower total T4 and T3 levels and elevated T3 uptake ratio values. As in the group with acute renal failure alone, total rT3 levels were normal and free rT3 values were elevated. The group with critical illness alone differed only in that the total rT3 concentrations were elevated in all patients. The alterations of thyroid hormone indices in acute renal failure are similar to those of other nonthyroidal illnesses with the exception of the normal total rT3 levels. This suggests that the failing kidney or the metabolic consequences of uremia specifically affect rT3 metabolism.     

Selenium Deficiency and Thyroid Function in Acute Renal Failure

The lethality of acute renal failure exceeds 50% due to multiorgan dysfunction. In such critically ill patients a reduction of thyroid hormone concentrations without clinical symptoms or laboratory evidence of hypothyroidism frequently occurs. Selenium has recently been shown to play a major role in thyroid hormone metabolism. The aim of this study was to investigate the possible influence of selenium on thyroid hormone metabolism in acute renal failure. Changes in thyroid metabolism were related to the severity of multiorgan failure and to the clinical course. Thyroxine (T4), tri-iodothyronine (T3), free-T4, free-T3, thyrotropin (TSH), serum creatinine, and plasma selenium concentrations in 28 patients (mean age 60 ± 13) with acute renal failure and multiple-organ dysfunction syndrome were determined initially, and every 3 days after hospital admission. The plasma selenium concentration was found to be reduced compared to normal controls (32 ± 14 vs. 70–120 μg/L). T4 (56 ± 15 nmol/L, normal range 64–148), T3 (1.31 ± 0.38 nmol/L, normal range 1.42–2.46), free-T3 (3.1 ± 1.0 pmol/L, normal range 4.7–9.0), and free-T4 (10.8 ± 4.0 pmol/L, normal range 10.3–25.8) values were low in 50–70% of the patients at the time of presentation. Plasma TSH concentrations were within the normal range (0.59 ± 0.79 mU/L, normal range 0.25–3.1), and no clinical symptoms of hypothyroidism were observed. T4 concentration was higher in patients who survived acute renal failure compared to nonsurvivors (62 ± 22 vs. 51 ± 16 nmol/L, p < 0.05). Plasma selenium concentration was lower in patients with a severe organ dysfunction syndrome (36 ± 10 vs. 29 ± 19 μg/L) and correlated with the number of organ failures in these patients (r = –0.247, p < 0.05). T4 and free-T4 values paralleled decreasing selenium concentrations (r = 0.35, p < 0.05). Thyroid hormone levels were reduced in patients with acute renal failure without an increase in TSH. An increase in T4 concentrations became apparent during treatment and may be related to a favorable outcome in acute renal failure. Thyroid hormone concentrations paralleled plasma selenium levels, indicating a possible influence of selenium on thyroid function in acute renal failure.     

The effects of thyroid hormones on the formation of stress ulcers in the rat

The Low T3 Sick Syndrome is a syndrome of low triiodothyronine (T3), low to normal thyroxine (T4), and a nonelevated thyrotropin despite the low T3 levels. This syndrome is frequently encountered in critically ill patients. These same patients are also at higher risk to develop acute stress ulcerations. The objective of this study was to access the effects of low circulating thyroid hormone levels on the development of stress ulcers in the rat. Rats having had previous surgical thyroidectomies were subjected to individual restraint stress; these animals had a significantly increased incidence of stress ulcers when compared to euthyroid stressed controls (1.6 +/- 0.4 ulcers vs 0.5 +/- 0.2 ulcers per animal, P less than 0.05). Surgically thyroidectomized (hypothyroid) animals who were given T3 replacement and then stressed, had ulcer rates similar to normal stressed controls (0.5 +/- 0.2 ulcers per animal). We conclude that low circulating thyroid hormones have an ulcerogenic effect, and that replacement of T3 in rats with surgical hypothyroidism reverses this effect.     

Altered hormonal activity in severely ill patients after injury or sepsis

We studied the hormonal millieu and possibility of altered thyroid function in 25 patients in a surgical intensive care unit (ICU) who had severe life-threatening illnesses. Sixteen patients had septic complications and nine patients had multiple-system injuries. On admission to the ICU, serial measurements were begun of thyroxine (T4), triiodothyronine (T3), T4-binding globulin, thyrotropin (thyroid-stimulating hormone [TSH]), corticotropin (adrenocorticotropic hormone [ACTH]), cortisol, prolactin, human growth hormone, catecholamine, insulin and glucose, lactate, retinol-binding protein, prealbumin, and transferrin levels. All patients initially had low normal levels of T4 (4.5 +/- 2 micrograms/dL) and T3 (55 +/- 26 ng/dL), with normal TSH levels (2.3 +/- 2.3 microU/mL) (the "low T3 syndrome"). The 11 surviving patients had their levels increase to normal before leaving the ICU (T4, 7.0 +/- 2.1 micrograms/dL; T3, 110 +/- 48 ng/dL; and TSH, no change). The 14 patients who died showed further decreases before death (T4, 2.6 +/- 2.1 micrograms/dL; T3, 30.6 +/- 23.5 ng/dL; and TSH, 0.9 +/- 0.7 microU/mL). The corticotropin, cortisol, prolactin, and growth hormone levels were normal throughout the study. Catecholamine levels were high initially and decreased in surviving patients. Epinephrine levels increased greatly in nonsurvivors before death, and the norepinephrine-epinephrine ratio decreased from 5.7:1 to 2:1. After protirelin (thyroid-releasing hormone [TRH]) stimulation, the TSH level increased either minimally or not at all in six patients who eventually died. This indicates hypothalamic-pituitary dysregulation or suppression, and altered release and/or peripheral metabolism of T4. Whether this represents a deficiency of thyroid hormone for cell and organ function remains to be established.     

甲状腺动脉栓塞治疗Graves病后甲状腺激素水平的变化

目的探讨甲状腺动脉栓塞治疗格雷夫斯病（GD）后5年内甲状腺激素水平的变化情况。方法回顾性分析49例接受甲状腺动脉栓塞治疗的GD患者术前、术后3天、7天、1个月、3个月、1年、3年、5年的T3、T4、FT3、FT4、TSH值变化。结果栓塞术后7天T3、T4,FT3、FT4均开始下降,至1～3个月最低,1年时反弹,之后呈现缓慢下降或小范围波动;术后3～7天,TSH下降至正常值以下,之后在正常范围内波动。结论甲状腺动脉栓塞治疗GD术后1～3个月甲状腺激素降至最低,1年开始反弹,提示术后1年是疾病复发的时间节点。     

Thyroid Function in Renal Failure

Renal failure is often associated with abnormal thyroid function tests which may make the diagnosis of thyroid dysfunction difficult (Table 1). As many as one-half of patients with renal failure have low thyroid function indices. Although clinically the patients are usually euthroid, there is evidence from animal and human studies that there may be some degree of tissue hypothyroidism in patients with renal failure. Whether this tissue hypothyroidism reflects an adaptive reaction to the uremic state is not clear.
Contributory factors to the alteration in thyroid function tests in renal failure are multiple and include poor nutritional status, medications, metabolic disturbances, hemodialysis, and associated nonthyroidal illnesses. All of these are known to affect thyroid function tests, and it is difficult to dissociate their influence from that of the uremic state. In most instances, the changes in thyroid function tests are similar to those encountered during nonthyroidal illness and include low levels of T₃, with normal or low levels of T₄, a variable free thyroxine index, and a normal, suppressed, or elevated level of TSH. One feature distinguishing renal failure from other non-thyroidal illnesses is the often normal rT₃ and elevated free rT₃ levels seen in acute and chronic renal failure. This appears to be related to the increased binding of rT₃ to intracellular binding proteins.
During hemodialysis, the free T₄ level is elevated transiently but may be abnormally elevated or low in the presence of a coexistent nonthyroidal illness. TSH is normal or only slightly elevated.
Transplant patients, who often receive high doses of steroids, may have abnormal thyroid function tests, in particular hypothyroxinemia and suppressed levels of basal TSH.     

A trial of thyroxine in acute renal failure

A trial of thyroxine in acute renal failure. BACKGROUND: Acute renal failure (ARF) remains a serious medical problem with a high mortality rate. Efforts to shorten the course of ARF might reduce this mortality. Since thyroxine has been shown in experimental models to shorten the course of ARF, we designed a trial to determine if a defined course of thyroxine would alter the course or change the mortality of clinical ARF. METHODS: A prospective, randomized, placebo-controlled, double-blind trial of thyroxine was carried out in patients with ARF. End points were the percentage requiring dialysis, the percentage recovering renal function, time to recovery, and mortality. RESULTS: Fifty-nine patients were randomized to receive either thyroxine or placebo. The groups were well matched in terms of basal and entry creatinines, age, sex, APACHE II scores at entry, and percentage oliguric. Baseline thyroid functions, including T3, T4, rT3, and thyroid stimulating hormone (TSH) levels, were equal between the two groups and typical of patients with euthyroid sick syndrome. Thyroxine resulted in a progressive and sustained suppression of TSH levels in the treated group, but had no effect on any measure of ARF severity. Mortality was higher in the thyroxine group than the control group (43 vs. 13%) and correlated with suppression of TSH. CONCLUSIONS: In contrast to the beneficial effects seen in experimental ARF, thyroxine has no effect on the course of clinical ARF and could have a negative effect on outcome through prolonged suppression of TSH. Critically ill euthyroid sick patients should not be replaced with thyroid hormone.     

Thyroid hormone alterations in patients with shock and injury

Serum concentrations of total T3 and T4, free T4, rT3, TSH, TBG and cortisol were measured on arrival in hospital in 33 adult injured patients, 26 of whom were received directly from the accident. Serum cortisol levels and all thyroid indices, except TBG, were altered substantially by injury. Compared with values from 57 healthy volunteers, statistically significant (P less than 0.01) decreases were found in the mean serum free and total T4 concentrations and the rT3 level. Similarly significant (P less than 0.001) increases were seen in the mean serum T3, TSH and cortisol concentrations. Repeated assessment of thyroid function in six patients suggested a biphasic response to injury by TSH, T3 and rT3. The first phase was of short duration (1-2 h). Serum levels of TSH and T3 were above normal, and rT3 was decreased. These data suggest participation by the thyroid in the 'fight-or-flight' response to life-threatening stress. The second phase was fully established 6-18 h after injury and was characterized by reductions in serum TSH, T3 and total and free T4 and a rise in rT3. This pattern persisted throughout the 2-week period of measurement. Thus, as in other critical illnesses, the 'low T3' syndrome is common in severely injured patients. However, changes in thyroid hormone metabolism after injury are of greater intensity and longer duration.     

Assessment of thyroid function with hormone assays

Measurement of serum thyroid hormone and TSH levels provide diagnostic information in the majority of patients with thyroid dysfunction. The test strategy in hyperthyroidism differs from that in hypothyroidism. Serum T4 is a good test for hyperthyroidism in patients with normal thyroid hormone-binding protein levels. When binding proteins are abnormal serum free T4 is a much more accurate test for hyperthyroidism than serum T4. Serum T3 and the TSH response to TRH are useful tests for the early diagnosis of hyperthyroidism. Serum TSH is a very sensitive indicator of primary hypothyroidism rising already at the subclinical stage of the disease. Serum T4 and free T4, but not serum T3, are useful for the verification of clinical hypothyroidism. Determination of the TRH-stimulated TSH level is important for the differential diagnosis of pituitary and hypothalamic hypothyroidism. It is imperative to recognize that thyroid tests are often abnormal in various non-thyroidal diseases and that administration of drugs can affect these tests. Serum rT3 is of some value for the assessment of thyroid function in patients with non-thyroidal disease.     

Nonthyroidal illness syndrome in enterocutaneous fistulas

Background

The aim of this study was to investigate the incidence, etiology, clinical outcomes, and prognosis of nonthyroidal illness syndrome (NTIS) in patients with enterocutaneous fistulas.

Methods

We prospectively collected 226 patients with enterocutaneous fistulas. Demographics, Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment scores, C-reactive protein, body mass index, albumin, and thyroidal hormones were evaluated for each patient.

Results

The incidence of NTIS was 57.5% in patients with enterocutaneous fistulas. Age and the APACHE II and Sequential Organ Failure Assessment scores were significantly higher, whereas albumin was lower in the NTIS group compared with those in the euthyroid group. A decreased sum activity of deiodinases and a reduced ratio of total thyroxin/free thyroxin and total triiodothyronine/free triiodothyronine were observed in the NTIS group. Patients with NTIS suffered longer durations in the intensive care unit and higher possibilities of mechanical ventilation. The cumulative survival rate was significantly lower in the NTIS group.

Conclusions

NTIS was common, and patients with NTIS displayed worse clinical outcome and prognosis. A hypodeiodination condition and a potential thyroid hormone–binding dysfunction may play a role in the etiology of NTIS. A low serum albumin concentration and a high APACHE II score were risk factors of NTIS in enterocutaneous fistulas.     

Thyroid hormones in conditions of chronic malnutrition. A study with special reference to cancer cachexia.

Circulating levels of thyroid hormones (T4, free T4, T3) and reverse tri-iodo thyronine (rT3) and thyroid-hormone binding globulin were related to the nutritional state of patients with cancer cachexia, patients with malnutrition due to other reasons and to well-nourished patients with acute illness. Hospitalized weight-stable and well-nourished patients served as controls. Malnourished patients with or without cancer and acutely ill patients had a low T3 syndrome involving both peripheral metabolism of thyroid hormones and the hypothalamus-pituitary-thyroid gland axis. T3 levels were correlated to altered protein metabolism and protein nutritional state. There were pronounced elevations of circulating rT3 concentrations in patients with serum albumin concentration less than 35 g/l irrespective of diagnosis. The results indicate that the low T3 syndrome in our patients is secondary to insufficient caloric intake. It seems to be maintained by the abnormal nutritional state and is related closely to protein metabolism. The authors found no differences between the low T3 syndrome in cancer patients suffering from cachexia compared with that of patients with malnutrition caused by other factors.     

Thyroid function in brain-dead donors

Twenty brain-dead potential organ donors were studied prospectively to establish thyroid function. Two or three consecutive blood samples were obtained during brain death. Seven times a sample was available before brain death occurred. Free triiodothyronine (FT3) fell in most patients (80%). Very low (<1.6 pmol/l) and subnormal levels (between 2 and 3 pmol/l) were found in 65% and 15% of the patients, respectively. Serum reverse total triiodothyronine (rT3) was inversely correlated with FT3. Free thyroxine (FT4) was less often decreased (mean 14.68±1.42 pmol/l) and 35% of the patients had normal levels. Mean thyroid stimulating hormone (TSH) remained normal (0.71±0.15 U/ml). The study of consecutive samples during brain death did not show a constant, progressive decrease in hormonal levels. There is no statistical difference between values observed before and after brain death. No correlation was found between FT3 levels and hemodynamic data or immediate allograft function. The pattern of thyroid function in these patients was typical of the sick euthyroid syndrome with a low T3 or low T3 and low T4 serum levels. This syndrome usually does not need to be treated. However, many experiment findings and some clinical data argue in favor of T3 therapy in donors and possibly in recipients. The dosage regimen must be adjusted to be effective without causing harm to multiorgan donors before it can be widely used. It remains to be proved that low FT3 serum indicates low intracellular FT3 and worse metabolic function in clinical conditions.     

肾病综合征伴甲状腺激素水平异常患者临床病理分析

目的检测肾病综合征（nephroticsyndrome,NS）患者的甲状腺激素（TH）水平,探讨NS伴TH异常者的临床特点及病理分布。方法选择符合NS诊断标准且既往无甲状腺相关疾病史的患者143例,所有患者均测定TH并进行肾活检,分析总结其临床特点、病理类型分布及与足细胞病的相关性等。结果①143例NS患者中,TH水平正常者34例（TH正常组）,TH水平异常者109例（TH异常组）,其中非甲状腺疾病综合征96例,自身免疫性甲状腺疾病13例,桥本氏甲状腺炎11例,甲状腺功能减退症1例,Graves甲状腺功能亢进1例。②TH正常组24h尿蛋白定量明显低于TH异常组,白蛋白水平明显高于TH异常组,总胆固醇水平明显低于TH异常组。③TH异常组中,白蛋白水平与血清游离三碘甲状腺原氨酸（FT3）、血清游离甲状腺素（FT4）水平呈正相关（r=0．551、0．642,P〈0．01）,与促甲状腺激素（TSH）水平呈负相关（r=-0．251,P〈0．01）。总胆固醇水平与FT4呈负相关（r=-0．427,P〈0．01）、与TSH（r=0．289,P〈0．01）呈正相关,与FT3无相关性。④109例NS并TH水平异常患者肾活检病理显示,系膜增生性肾炎43例,膜性肾病40例,IgA肾病9例,膜增生性肾小球肾炎4例,局灶节段硬化性肾小球肾炎11例,微小病变肾病2例。表现为足细胞病者56例、非足细胞病53例,两者间TH水平差异无统计学意义（P〉0．05）。结论①NS患者临床易合并TH异常,表现以非甲状腺疾病综合征为主,自身免疫性甲状腺疾病次之。②NS合并TH异常者比正常者临床表现更突出。③NS合并TH异常者病理以系膜增生性肾炎、膜性肾病多见。其表现为足细胞病者与非足细胞病者病例数相当。     

Hypothyroidism in infants with nephrotic syndrome

Thyroid function indices were studied in five children with nephrotic syndrome in the 1st year of life. Four had primary hypothyroidism as defined by low serum free tri-iodothyronine (FT₃) and free thyroxine (FT₄), and high serum thyroid-stimulating hormone (TSH) levels. One patient with low serum FT₃ and FT₄ had a normal TSH level. T₄ replacement therapy lowered TSH to normal levels in all four patients and normalized FT₄ in three of them. There were no significant changes in serum FT₃ levels. Adrenal function was studied in three patients, none had adrenal calcification or hypoadrenocorticism. This study supports the existence of a hypothyroid state in some infants with nephrotic syndrome. Routine thyroid screening and early replacement therapy is recommended.     

Euthyroid sick syndrome in trauma patients with severe inflammatory response syndrome

Objective： To investigate the alternations of thyroid hormone in traumatic patients with severe inflammatory response syndrome （SIRS）. Methods： Fifty traumatic patients with severe SIRS were enrolled and divided into two groups according to whether they presented multiorgan dysfunction syndrome （MODS）. Thyroid hormone measurements were taken, including total triiodothyronine （ TT3 ）, total thyroxine （TT4）, free triiodothyronine （FT3）, free thyroxine （ FT4 ） and thyroid stimulating hormone （TSH）. The acute physiology and chronic health evaluation II （ APACHE II ） score was calculated according to clinical data. The outcomes of recovery or deterioration were recorded, as well as the length of time from the onset of SIRS to the time thyroid hormones were measured. Results： Euthyroid sick syndrome （ESS） was presented in 45 cases. TT3 level was negatively correlated with APACHE II score （r = -0.330, P 〈0. 05）, and TT3/TI＇4 value was negatively correlated with the duration of SIRS（ r = -0.316, P〈0.05）. TT3, TT4 and levels in MODS patients were significantly lower than those without MODS （ P 〈 0.05 ）. MODS patients got low TT4 or FT4 level more frequently than those without MODS （ P 〈 0.05 ）. Compared with the patients in normal TSH group, the patients with decreased TSH had lower T3, T4, recovery rate and higher APACHE II scores, MODS incidence, but there was no difference between two groups （P〉0.05）. Conclusions： Trauma patients with severe SIRS have high possibility to get ESS, which occurs more frequently and severely in MODS patients. It shows the influences of SIRS on the thyroid axes. With the persistence and aggravation of SIRS, there is a progressive reduction of thyroid hormone.     

Thyroid function in brain-dead donors

Abstract. Twenty brain-dead potential organ donors were studied prospectively to establish thyroid function. Two or three consecutive blood samples were obtained during brain death. Seven times a sample was available before brain death occurred. Free triiodothyronine (FT3) fell in most patients (80%). Very low (< 1. 6 pmol/1) and subnormal levels (between 2 and 3 pmol/1) were found in 65% and 15% of the patients, respectively. Serum reverse total triiodothyronine (rT3) was inversely correlated with FT3. Free thyroxine (FT4) was less often decreased (mean 14. 68 1. 42 pmol/1) and 35% of the patients had normal levels. Mean thyroid stimulating hormone (TSH) remained normal (0. 71 0. 15 μTJ/ml). The study of consecutive samples during brain death did not show a constant, progressive decrease in hormonal levels. There is no statistical difference between values observed before and after brain death. No correlation was found between FT3 levels and hemodynamic data or immediate allograft function. The pattern of thyroid function in these patients was typical of the sick euthyroid syndrome with a low T3 or low T3 and low T4 serum levels. This syndrome usually does not need to be treated. However, many experiment findings and some clinical data argue in favor of T3 therapy in donors and possibly in recipients. The dosage regimen must be adjusted to be effective without causing harm to multiorgan donors before it can be widely used. It remains to be proved that low FT3 serum indicates low intracellular FT3 and worse metabolic function in clinical conditions.     

Thyroid hormone responses in hemorrhagic shock: study in dogs and preliminary findings in humans

One hour of hemorrhagic shock in the dog produces alterations in thyroid hormone metabolism far exceeding those seen after elective surgery or thermal injury. The changes in plasma thyroid hormone levels cannot be fully explained by carrier protein loss. Plasma concentrations of total thyroxine (T4) and triiodothyronine (T3) were significantly decreased after only 20 minutes of shock, continued to decrease throughout shock and resuscitation, and remained depressed for several days thereafter. Both hormones reached nadirs during volume replacement of 42% and 17% of baseline, respectively. The total T4 level normalized by the fifth postshock day, but the T3 concentration was still depressed on the ninth day. Plasma albumin, the principal canine thyroid hormone carrier, was significantly reduced 20 minutes after hemorrhage and remained low throughout convalescence. Concentrations of free T4 and T3 decreased during shock, but not as much as the total T4 and T3 concentrations. Reverse T3 levels, corrected for albumin loss, and T3 uptake values were increased during shock and resuscitation. Similar alterations in circulating thyroid hormone concentrations were seen in three patients with major traumatic injury and/or shock. The thyroid hormone changes in shock may represent another example of the "euthyroid sick syndrome."