Changes Of The Blood Serum Level Of Thyroid Hormone In Patients Undergoing Radical Mastectomy Under Propofol General Anesthesia

[Objective] It is called euthyroid sick syndrome (ESS) that happens with a normal or depressed serum level of tetraiodothyronine (T4), decreased level of triiodothyronine (T3) and the increase of reverse triiodothyronine (rT3), which happens in some non-thyroid systemic diease. ESS also happens in some conditions such as cancer, postoperative, wound, and so on. Breast carcinoma is the most common cancer in females, and it is proved by many researchs that breast cancer patients have a low level of thyroid hormone (TH) and that TH may has close contact with the occurrence, development and prognosis of breast cancer. The main treatment of breast cancer is surgery, radical mastectomy, and general anesthesia with laryngeal mask airway and propofol is widely used is radical mastectomy. But it is not sure that, whether propofol anesthesia will affect the serum level of TH and affect the recovery from surgery. And till now, there is lack of research about this field. The purpose of this study is to investigate the changes of thyroid hormone (TH) before and after general anesthesia with propofol and radical mastectomy.[Method] All the patients were not injected drugs before surgery, and forbidding diet for8h was necessary. As patient enter the operating room, multifunctional monitor and BIS were connected.5ml blood was gotten from vein. Anesthesia induction was conducted with midazolam0.08mg/kg, fentanyl0.15mg, rocuronium0.6mg/kg, proporfol1mg/kg, fast induction, inserting laryngeal mask, adjusting the pressure of cuff to make sure that no gas leak. Then, the tracheal catheter was connected to anaesthesia machine, on a ventilation mode of intermittent positive pressure ventilation(IPPV, VT=7mL/kg, f=12/min). After the beginning of surgery,0.15mg fentanyl was administered. All the patients were not given local hypodermic injection of epinephrine. During the surgery, target controlled infusion of proporfol was used with a pump to give continuous anesthesia and keeping BIS ranging from40to60. The TCI pump was stopped at the time of sewing skin, at the same time, stopping IPPV and manually assisting their autonomous respiration. At the end of surgery,5ml blood was taken from upper arm subcutaneous vein. When the patient regained consciousness(tide volume came up to4ml/kg, breathing rate reach15±5/min, BIS >75, eyes open when called the name, OAA/S grade between calss1-2, being able to finish some simple order, such as mouth open, deep breath), the laryngeal mask was extracted out. Before sent out of the operating room, their secretion in mouth and respiratory passage must be cleaned. All the blood samples would be centrifuged in12hours(3,000r×15min), keeping the serum frozen under-20℃. When we got enough samples, we used ELISA to test T3, T4, FT3, FT4and TSH.[Result] Compared with the preoperative ones, postoperative T3, T4, FT3and TSH decreased significantly. There were positive correlations between dT3and P/W (r=0.626, P=0.001), and there was negative correlation between dFT3and P/W (r=-0.380, P=0.042), but none with other dTHs.[conclusion] General anesthesia with propofol and radical mastectomy might make TH decrease in breast cancer patient. Higher the P/W increased, lower the T3became.