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.     

Improvement of thyroid hormone profile and thyrotrophin (TSH) surge alterations in hemodialysis patients on erythropoietin treatment.

BACKGROUND, MATERIAL AND METHODS: This study was performed in 20 patients with end-stage chronic renal failure (CRF) and 10 healthy volunteers. All of the patients were on regular hemodialysis treatment (RHD), 10 of whom were on recombinant human erythropoietin (rHuEPO) therapy. Hematocrit levels of the patients with CRF on rHuEPO were between 0.30 to 0.33 and not on rHuEPO were below 0.24. Baseline serum T3, T4, fT3, fT4 and TSH levels were measured and TRH stimulation test was performed in patients and control subjects. Serum TSH levels were measured hourly during the afternoon (2 to 5 p.m.) and at night (10 p.m. to 2 a.m.) to determine the nocturnal rhythm of TSH. RESULTS: The mean T3 in rHuEPO, not rHuEPO and control groups were 98.01 +/- 5.54, 70.55 +/- 7.09, 98.29 +/- 4.2 ng/dl; T4 6.47 +/- 0.68, 6.39 +/- 0.59, 8.35 +/- 0.46 ng/dl; fT3 2.24 +/- 0.19, 1.52 +/- 0.24, 2.29 +/- 0.17 pg/ml and fT4 0.88 +/- 0. 14, 0.75 +/- 0.14, 0.97 +/- 0.10 ng/dl, respectively. These values were significantly lower in patients not on rHuEPO compared to controls (p < 0.05). In patients on rHuEPO only T4 values were lower than in the controls (p < 0.05). In patients not on rHuEPO the T3, and fT3 were significantly lower than the values of patients on rHuEPO treatment (p < 0.05). Normal in 8 (80%), blunted in 1 (10%), no TSH response in 1 (10%) to TRH stimulation were obtained in rHuEPO group. TSH response was normal in 1 (10%), and delayed in 9 (90%) patients not on rHuEPO. The circadian nocturnal rhythm of TSH was abnormal in 8 (80%) patients not on rHuEPO, in 2 (20%) patients on rHuEPO. As a result, CRF and RHD distorts the circadian TSH rhythm and substantially change the thyroid hormone profile probably by affecting hypothalamic-pituitary-thyroid axis. Distortion of the circadian rhythm of TSH and TSH response to TRH points to a defect at the level of hypothalamus and pituitary gland. CONCLUSION: rHuEPO treatment has some beneficial effects on hypothalamo-pituitary-thyroid axis in the patients on RHD.     

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.     

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.     

Influence of long term erythropoietin therapy on the hypothalamic-pituitary-thyroid axis in patients undergoing capd

OBJECTIVE: Treatment of anemia with recombinant human erythropoietin (rHuEpo) in hemodialysis patients has been associated with improvement of several abnormalities in hypothalamic-pituitary function. The aim of the present study is to investigate the effects of long term erythropoietin therapy on the hypothalamic-pituitary-thyroid hormone axis in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). DESIGN: Single center, prospective study. PATIENTS AND METHODS: Ten patients who were clinically stable and had been on CAPD were evaluated. Eleven age and sex matched healthy volunteers were chosen as controls. All of the patients were clinically euthyroid. All patients were on CAPD therapy and none of them had received rHuEpo treatment previously. In all patients after basal estimations of free T3, free T4, TSH, GH and prolactin levels, a bolus of 400 microg TRH was administered intravenously. Levels of TSH, GH and prolactin were measured in blood samples collected every 30 min of the 3 h test period. After the treatment with rHuEpo, TRH test with the same protocol was repeated. RESULTS: Before the improvement in serum hemoglobin levels with rHuEpo treatment, the patients on CAPD showed abnormal hypothalamic-pituitary-thyroidal functions, including delayed and prolonged TSH (NS), paradoxically elevated GH (p < 0.001) and increased and prolonged prolactin (p = 0.001) responses to TRH. After improvement of anemia with rHuEpo no significant difference was found between the patients and control groups for baseline TSH levels. In the patients peak TSH level and AUC of TSH secretion were significantly reduced after the treatment (p < 0.05 for both). Furthermore the improvement in anemia did not eliminate the paradoxic GH and prolonged prolactin responses to TRH administration. CONCLUSION: Some hypothalamic-pituitary-thyroid function abnormalities including delayed and blunted TSH, increased and prolonged prolactin and paradoxical GH responses to TRH administration were observed in uremic patients treated with CAPD and the improvement in anemia with rHuEpo seems to cause slight changes on the hypothalamic-pituitary-thyroid axis and peripheral thyroid hormones.     

Spontaneous pituitary-thyroid function after surgical treatment of nontoxic goitre. A controlled long-term study

The free thyroxine index (FT4I), triiodothyronine (T3) and thyroid stimulating hormone (TSH) in serum and the peak serum TSH (TRH test) were measured in 18 patients with nontoxic uninodular goitre and 32 patients with nontoxic multinodular goitre before and 3, 6, 12, 24 and 36 months after goitre resection. Thyroid hormone therapy was not given postoperatively. Resection of non-toxic goitre provoked a transient rise in TSH baseline level, with peak about one year after surgery. Three years after the resection the TSH baseline had returned to the preoperative level. The TSH changes were significantly more pronounced in the multinodular goitrous group, in which resection was bilateral, than in the uninodular goitrous group. The changes in serum FT4I and serum T3 were of moderate degree and most pronounced in the multinodular group. During long-term observation, serum FT4I increased slightly but significantly in both groups, but serum T3 showed significant reduction, albeit within reference range. The results of the study suggest that thyroid hormone therapy as a routine procedure after simple goitre resection lacks a tenable rational basis.     

Comparison of pituitary-thyroid function in patients with endstage renal disease and in age- and sex-matched controls

The response to i.v. bolus thyrotropin-releasing hormone (TRH) of 14 dialysis patients with end-stage renal disease (ESRD) was compared to the response of 14 age- and sex-matched renal clinic patients (controls) with normal renal function (serum creatinine concentrations less than 1.2 mg/dl). The mean basal serum levels of thyrotropin (TSH) were similar in the two groups. There was no difference between the two groups in the mean maximal increase in TSH after TRH (6.3 microU/ml and 7.2 microU/ml in ESRD and control groups, respectively); The rate of fall in TSH from 60 to 90 min after TRH was slower in the ESRD group than in the controls. The mean increase in serum triiodothyronine (T3) concentration after TRH was similar in both groups (25.4 ng/dl, ESRD; 18.4 ng/dl, controls). As previously reported, basal serum T3 content was subnormal in the ESRD patients. Serum thyroxine (T4) concentrations were comparable in control and ESRD groups and did not change significantly during the 90-min TRH test in either group. We conclude that ESRD patients, clinically stable on dialysis, have normal pituitary TRH responsiveness and normal thyroidal response to endogenous TSH secretion, as compared with an age- and sex-matched group of patients with normal renal function. The results of this study support the contention that ESRD patients are eumetabolic.     

Influence of extradural blockade on serum thyroid hormone concentrations after surgery

To study the changes in thyroid hormone metabolism after surgery, the influence of neurogenic blockade by extradural local anaesthetics, and possible hormonal interactions, 16 women undergoing cholecystectomy were randomly allocated to two groups of eight each. All patients received general anaesthesia and in addition one group received extradural blockade for 24 h. Preoperatively and at 2, 4, 6, 12 and 24 h after skin incision arterial serum concentrations of thyroid hormones (T3, free T3, rT3, T4, free T4 and TSH), catecholamines (adrenaline and noradrenaline), cortisol and serum proteins (albumin, prealbumin and TBG) were determined. In both groups total T3, free T3, total T4 and TSH decreased significantly whereas free T4 was unchanged and rT3 increased. No differences between the extradural group and the controls regarding thyroid hormones were observed, in spite of suppressed catecholamine and cortisol concentrations in the extradural group as compared to the control group. All serum thyroid hormone binding proteins decreased significantly in both groups. Changes in thyroid hormone metabolism after surgery seem independent of neurogenic blockade by extradural local anaesthetics, and of plasma catecholamine and cortisol concentrations.     

Thyroid hormone changes after cardiovascular surgery and clinical implications

Alterations in serum concentrations of total triiodothyronine (TT3), total thyroxine (TT4), and thyroid-stimulating hormone (TSH) frequently occur in patients with nonthyroidal illnesses. These changes correlate with the severity of the illness and the prognosis. In this study, 44 patients undergoing a cardiovascular operation had significant declines in serum TT3 and TT4 levels during cardiopulmonary bypass and thereafter. Serum TT3 and TT4 concentrations reached their nadir at 30 minutes after the start of cardiopulmonary bypass with values (mean +/- standard error of the mean) of 0.77 +/- 0.12 nmol/L (50.4 +/- 7.6 ng/dL) and 68.2 +/- 10.2 nmol/L (5.30 +/- 0.79 micrograms/dL), respectively. The mean serum concentrations of TSH and TT4 returned to preoperative levels by the sixth day after operation, whereas TT3 levels remained low throughout the study period. The patients whose recovery was uneventful had higher serum TT3, TT4, and TSH levels than those who had complications or died. The trend toward recovery was initiated by a sharp increase in the serum TSH level and increases in serum TT3 and TT4 concentrations on the fourth day after operation. Patients with complications either did not show these changes or had only a transient increase in TT3 and TT4 levels. All of the patients had a normal serum free T4 level before anesthesia. Those with an uneventful recovery had a higher serum free T4 level on the sixth day after operation than those with complications. Two patients in the latter group had serum free T4 levels less than normal at that time.(ABSTRACT TRUNCATED AT 250 WORDS)     

Low free thyroxine concentrations and deficient nocturnal surge of thyroid-stimulating hormone in haemodialysed patients compared with undialysed patients.

BACKGROUND: There is little information on the differences in pituitary-thyroid function between undialysed and haemodialysed patients. METHODS: Serum concentrations of free thyroxine (T(4)) and free triiodothyronine (T(3)), measured by enhanced chemiluminescence immunoassay, and thyroid-stimulating hormone (TSH) were compared in undialysed (n=22) and haemodialysed patients (n=85). The response of the serum TSH concentration to exogenously administered thyrotropin-releasing hormone (TRH) and circadian variation in serum TSH were also studied in the two groups. RESULTS: Serum free T(4) concentration was significantly lower in haemodialysed than in undialysed patients (1.02+/-0.02 vs 1.33+/-0.06 ng/dl, P<0.0001). Serum concentrations of free T(3) and TSH were essentially the same for the two groups. The response of serum TSH concentration to TRH was basically the same. Serum TSH concentration in undialysed patients during the night and in the morning were 142.4+/-15.4% and 121.7+/-4.1% of that during the day, the differences being significantly different. A nocturnal surge of TSH was not observed in haemodialysed patients. CONCLUSIONS: Low serum free T(4) concentration and a deficient nocturnal surge of TSH were found in haemodialysed patients compared with undialysed patients. The deficient nocturnal surge of TSH may contribute to the lower serum free T(4) concentration in haemodialysed patients.     

Changes in plasma free thyroid hormones during cardiopulmonary bypass do not indicate triiodothyronine substitution.

Concentrations of free and bound thyroid hormone in plasma during cardiopulmonary bypass were determined in 10 patients. Ages ranged from 50 to 76 years (median 61 years). Apart from thyroxine and triiodothyronine, a number of other variables that might contribute to an altered thyroid state or binding of thyroxine and triiodothyronine to plasma proteins were measured (thyroid stimulating hormone, reverse triiodothyronine, albumin, nonesterified fatty acids, and cortisol). At the end of the observation, total triiodothyronine and total thyroxine concentrations were 86% and 70% (mean) of initial levels, respectively, and reverse triiodothyronine and albumin concentrations were both 74%. On the contrary, free triiodothyronine and free thyroxine levels rose to a maximum of 137% and 203% (mean), but normalized after heparin neutralization (86% and 102%). Thyroid-stimulating hormone concentration declined insignificantly during cardiopulmonary bypass, reaching a minimum at the time when body temperature was maximally depressed (74%), and then it normalized (101%). Plasma cortisol level did not rise above normal limits despite the major stress stimulus. In conclusion, total triiodothyronine and total T4 concentration in plasma of patients undergoing cardiac operations is lowered, while the exchangeable pool concentrations (plasma free triiodothyronine and free thyroxine) are elevated during bypass but return to control levels at the end of the operation. If serum changes truly reflect intracellular events, it does not seem likely that the myocardial cell is depleted of thyroid hormones after cardiopulmonary bypass, as recently claimed by others. This finding does not, however, exclude the possibility that a pharmacologic dose of triiodothyronine may be convenient for improvement of cardiac performance.     

腹部外科SIRS患者下丘脑-垂体-甲状腺轴的功能改变及机制探讨

目的：研究SIRS状态下下丘脑-垂体-甲状腺轴的功能改变并探讨其机制。方法：应用放射免疫分析方法测定25例病人的血清T3、T4、rT3、TSH、TRH水平,并与20例正常对照进行比较。结果：SIRS病人血清T3、T4水平低于对照组。TSH和TRH水平观察组高于对照组。结论：SIRS病人下丘脑-垂体-甲状腺轴的功能出现紊乱,其可能的机制是由于甲状腺本身的功能受到抑制以及应激刺激作用的结果。     

Two cases of TSH-secreting pituitary adenoma; endocrinological, diagnostic and therapeutic approach to the disease

Two cases of TSH-secreting pituitary adenoma were reported. Endocrinological and immunohistochemical features of these cases were described and problems in diagnosis and treatment of the rare disease are discussed. [case 1] A 28 year-old woman suffered from hyperthyroidism with a relatively high value of serum TSH (T3; 350 ng/dl, T4; 10.0 micrograms/dl, TSH; 24.5 microU/ml). She was treated with antithyroid drug and then underwent subtotal thyroidectomy. Although the levels of serum T3 and T4 were lowered to within normal range, the level of serum TSH still remained high. One month later, she developed frontal headache, amenorrhea and bitemporal hemianopsia. A CT scan showed an enhanced mass in the sellar and suprasellar region. Preoperative endocrinological studies showed elevated values of TSH (47 microU/ml) and its alpha-subunit (9.0 ng/ml). The levels of both T3 (190 ng/dl) and T4 (10.0 micrograms/dl) were near the upper normal limit. Serum TSH was suppressed by administration of exogenous T3, but did not respond to exogenous TRH, l-Dopa nor bromocriptine. Under the diagnosis of TSH-secreting pituitary adenoma, the patient was operated on by craniotomy and received local radiation therapy (50 Gy). In 1990, 12 years after the treatment, she is well and endocrinologically normal. Immunohistochemical study revealed that most tumor cells were positive for TSH. [case 2] A 28 year-old woman visited our hospital for examination of hyperthyroidism. Serum level of TSH was detectable (4.5 microU/ml). A CT scan performed at that time disclosed no pituitary tumor. Thyroid function was normalized by antithyroid drug, but the level of TSH was still high and progressively increased.(ABSTRACT TRUNCATED AT 250 WORDS)     

Surgical treatment of ischemic heart disease combined with hypothyroidism

Treatment for patients with ischemic heart disease and hypothyroidism contains many difficulties, such as a dilemma that thyroid hormone to hypothyroid patients may worsen angina. The purpose of this study is to propose an appropriate control of thyroid function in these patients before coronary artery bypass grafting (CABG), and to clarify the change of thyroid function during postoperative period. Because of progressive angina pectoris, five hypothyroidism patients underwent CABG. Preoperatively, minimal dose of L-Thyroxine (0-75 micrograms, daily) was administered orally to keep thyroid function at slightly low level before CABG. Ten consecutive CABG patients with normal thyroid function were selected as control group. Between both groups, there was no significant difference in age, coronary artery disease, and the number of bypass grafts. Serum T4, free-T4, T3, free-T3, and TSH were measured at 1st, 2nd, 3rd, and 7th P.O.D. In control group, pituitary-thyroid function was suppressed transiently. In hypothyroid group, T4 revealed no change and was kept at slightly low level during observed period. There was no significant difference in postoperative hemodynamics between both groups. Postoperatively all of hypothyroid patients got free from angina and received an adequate thyroid hormone replacement therapy without complications. It is concluded that CABG for patients with angina and hypothyroidism can be performed safely by keeping preoperative thyroid function at slightly low level.     

TRH: Pathophysiologic and clinical implications

Summary Thyrotropin releasing hormone is thought to be a tonic stimulator of the pituitary TSH secretion regulating the setpoint of the thyrotrophs to the suppressive effect of thyroid hormones. The peptide stimulates the release of normal and elevated prolactin. ACTH and GH may increase in response to exogenous TRH in pituitary ACTH and GH hypersecretion syndromes and in some extrapituitary diseases.The pathophysiological implications of extrahypothalamic TRH in humans are essentially unknown.The TSH response to TRH is nowadays widely used as a diganostic amplifier in thyroid diseases being suppressed in borderline and overt hyperthyroid states and increased in primary thyroid failure. In hypothyroid states of hypothalamic origin, TSH increases in response to exogenous TRH often with a delayed and/or exaggerated time course.But in patients with pituitary tumors and suprasellar extension TSH may also respond to TRH despite secondary hypothyroidism. This TSH increase may indicate a suprasellar cause for the secondary hypothyroidism, probably due to portal vessel occlusion. The TSH released in these cases is shown to be biologically inactive.     

Hyaluronan based heparin free coated open and closed extracorporeal circuits for high risk coronary revascularization

This prospective randomized study compares the inflammatory response and fibrinolytic activation of fully coated/uncoated and open/closed extracorporeal circuits (ECC) in high risk patients. Over a 2-month period, 48 patients with EuroSCOREs 6 or greater undergoing coronary revascularization were prospectively randomized to one of the four perfusion protocols: Group 1: Closed and totally hyaluronan based heparin free coated (Vision HFO-GBS-HF, Gish Biomedical, Rancho Santa Margarita, CA) ECC with a soft-shell coated venous reservoir (SVR11S2-HFC, Gish Biomedical) and a hard-shell cardiotomy (CAPVRF44, Gish Biomedical) (n = 12); Group 2: Closed and totally uncoated identical ECC with soft-shell uncoated venous reservoir and a hard-shell cardiotomy (n = 12); Group 3: Open, totally hyaluronan based heparin free coated ECC (n = 12); and Group 4: Control-open, uncoated ECC (n = 12). Blood samples were collected at T1: Baseline; T2: 15 minutes after cardiopulmonary bypass (CPB) initiation; T3: before cessation of CPB; T4: 15 minutes after protamine reversal, and T5: in the intensive care unit. Serum IL-6 levels were significantly lower at T2 in all study groups, at T3 for coated groups, and T4 for closed+coated group (p < .05 versus control). Creatine kinase M-band (MB) levels in coronary sinus blood demonstrated well preserved myocardium after CPB in both coated groups versus Control (p < .05). Neutrophil CD11b/CD18 levels were significantly lower for all study groups versus control at T2, for both coated groups at T3 and only for closed + coated group at T4 (p < .05). Postoperative hemorrhage (mL) was 510 +/- 40 in closed + coated and 536 +/- 40 in open + coated groups (control: 784 +/- 48, p < .05). No significant differences in thrombin-antithrombin complex and free plasma hemoglobin were observed. Desorbed protein amount on ECC (mg/dL) was 1.7 +/- .01 in closed+coated, 2.01 +/- .01 in open+coated, and 3.3 +/- .015 in control groups (p < or = .05). Use of a closed and completely heparin free coated ECC may reduce neutrophil degradation, cytokine release characterized by improved clinical outcomes including reduced blood loss, reduced requirement for inotropes, and reduced atrial fibrillation.     

A recurrent case of TSH-PRL secreting microadenoma following hypothyroidism

A thirty-seven-year-old housewife whose chief complaints were recurrence of galactorrhea and amenorrhea three years after having a selective adenomectomy. Hormonal examination done as a result of the continuation of the endocrinism revealed a hyperprolactinemia and high level of TRH due to hypothyroidism. Serum prolactin responded to neither TSH stimulation nor L-Dopa suppression tests. In addition, serum TSH did not react to TRH test. Contrast enhancement CT showed an intrasellar enhancing mass the size of which was less than 1 cm in diameter. A unilateral septal transsphenoidal operation was performed; and a soft white-yellowish mass 7 X 5 X 5 mm in size was found in the left inferolateral aspect of the pituitary gland. Histological studies of frozen sections of this revealed it to be a pituitary adenoma, with the border between tumor and normal tissue being quite distinct. Immunocytochemical diagnosis further confirmed it to be both PRL and TSH producing adenoma. Electron microscopy showed more than three different hormone-producing cells. The PRL cells contained large, and the TSH cells had small hormone granules; but some tumor cells contained secretory granules of both sizes suggesting production of both PRL and TSH in the cytoplasm. It is necessary in the management of patients like this, during the post-operative period, to adequately institute a thyroid hormone replacement therapy so as to prevent recurrence.     

Evaluation of anterior pituitary function in adult patients with craniopharyngiomas

Summary Serum LH, FSH, TSH, PRL, GH and cortisol levels were measured in 10 patients with a craniopharyngioma both before and after a combined insulininduced hypoglycaemia, GnRH and TRH test. In pre-operative studies, only two patients did not show hormonal abnormalities, while eight patients had deficiencies of one or more hormones. The most frequent abnormality was GH deficiency (six cases), followed by gonadotropin (four cases), cortisol (four cases), and TSH (one case), whereas four patients showed high serum PRL values. In post-surgical studies, a significant improvement of pituitary function was observed in two cases, whereas an impairment of previously normal corticotropin reserve was recorded in another case. The data obtained suggest that endocrine abnormalities in patients with Craniopharyngiomas are irreversible in most cases.     

连续星状神经节阻滞对重度颅脑损伤患者血清甲状腺激素及皮质醇水平的影响

目的 探讨连续星状神经节阻滞对重度颅脑损伤患者血清甲状腺激素[三碘甲状腺原氨酸(T3)、甲状腺素(T4)、反三碘甲状腺原氨酸(rT3)、促甲状腺激素(TSH)]及皮质醇(Cor)水平的影响.方法 急诊行开颅手术的重度颅脑损伤患者80例,性别不限,年龄22～61岁,ASA分级Ⅱ或Ⅲ级,格拉斯哥昏迷量表评分3～8分,采用随机数字表法,将患者随机分为2组(n=40):对照组(C组)和连续星状神经节阻滞组(SGB组).气管插管后SGB组于开颅侧行连续SGB,注射0.2%罗哌卡因7ml后,持续输注0.2%罗哌卡因2 ml/h,持续时间为48 h;2组术后均予常规治疗.于术前30 min、术后3、7 d采集静脉血样,采用放射免疫法测定血清T3、T4、rT3、TSH及Cor浓度;术后90 d采用格拉斯哥预后评分判定临床疗效.结果 与C组比较,SGB组术后血清T3浓度升高,T4、rT3、TSH和Cor浓度降低(P＜0.05或0.01),SGB组临床疗效分级优于C组(P＜0.05).结论 连续星状神经节阻滞可有效减轻重型颅脑损伤患者的应激反应,改善下丘脑-垂体-甲状腺轴功能,有助于患者恢复.

Abstract：

Objective To investigate the effects of continuous stellate ganglion block (SGB) on serum thyroid hormone and cortisol levels in patients with severe brain injury.Methods Eighty ASA Ⅱ or Ⅲ patients with severe brain injury aged 22-61 yr undergoing emergency craniotomy were randomly divided into 2 groups ( n = 40 each): control group (group C) received routine treatment only and continuous SGB group (group SGB) received continuous SGB with 0.2% ropivacaine besides routine treatment. SGB was performed on the operated side after induction of general anesthesia and tracheal intubation. An epidural catheter was placed. A bolus of 0.2% ropivacaine 7 ml was followed by continuous infusion of 0.2% ropivacaine at a rate of 2 ml/h. Continuous SGB was maintained for 48 h. Successful SGB was confirmed by increase in skin temperature by ≥1.5℃ behind earlobe on the operated side.Venous blood samples were obtained at 30 min before and 3 and 7 day after operation for determination of serum thyroid stimulating hormone (TSH), triiodothyronine (T3) ,thyroxine (T4) , reverse triiodothyronine(rT3) and cortisol concentrations. Glasgow prognosis score was used to evaluate the clinical results at 3 months after operation. Results Serum T4 , rT3 , TSH and cortisol concentrations were significantly lower while the serum T3 concentration was higher in the SGB group than in group C at 3 and 7 d after operation. The clinical results were significant better in SGB group than in group C according to Glasgow prognosis scores at 3 months after operation. Conclusion Continuous SGB can inhibit the stress response, and improve hypothalamus-pituitary-thyroid gland axis function and is helpful to patient's recovery from injury.     

Lack of nocturnal serum thyrotropin (TSH) surge in patients with chronic renal failure undergoing regular maintenance hemofiltration: a case of central hypothyroidism

Thyrotropin (TSH) secretion was evaluated in a group of patients with chronic renal failure (CRF) undergoing regular maintenance hemofiltration and in normal controls. The study group included 68 patients (39 males and 29 females, age range 39-73 years, mean: 53 years). In all patients blood was drawn at 08:30-09:00 h; in 20 patients the nocturnal (24:00-02:00 h) serum TSH peak was also evaluated; 12 patients underwent stimulation test with synthetic TSH-releasing hormone (TRH). TSH was measured by an ultrasensitive immunoradiometric assay. CRF patients showed a significant decrease in serum total and free thyroxine and triiodothyronine concentrations, which in a substantial proportion of subjects were below the lower normal limit. Serum reverse triiodothyronine and thyroxine-binding globulin values did not differ in the two groups. Despite this trend of thyroid hormones to decrease, no patient had supranormal TSH values as in primary hypothyroidism. While the mean morning TSH concentrations of CRF patients did not differ from those of controls, the mean nocturnal values were significantly reduced in CRF (1.0 +/- 0.2 vs 3.2 +/- 0.4 mU/l, p less than 0.0005) and the nocturnal serum TSH surge was not observed in 18 of the 20 patients (90%) in whom it was evaluated. The mean serum TSH peak value after TSH-releasing hormone (TRH) administration was also reduced in CRF patients, and the TSH response to TRH was blunted in 3 out of 12 patients (25%). The results of this study demonstrate a major impairment of TSH secretion in CRF, which baseline TSH measurements in the morning and the evaluation of the TSH response to TRH may not reveal.(ABSTRACT TRUNCATED AT 250 WORDS)