Auchus R J, Shewbridge R K, Shepherd M D
Department of Endocrinology (PSME), Wilford Hall Medical Centre (59MDW), Lackland AFB, TX 78236, USA.
Clin Endocrinol (Oxf). 1997 Jan;46(1):21-7. doi: 10.1046/j.1365-2265.1997.d01-1748.x.
Recent data suggest that recovery of anterior pituitary function promptly follows surgical decompression and that hypothalamic-pituitary-adrenal axis assessment need not be delayed following transsphenoidal pituitary surgery. We hypothesized that one protocol for both glucocorticoid supplementation and axis investigation prior to discharge may be applied to all transsphenoidal pituitary surgery patients. The protocol examined the merits of preoperative testing and of basal and hypoglycaemia-stimulated cortisol and ACTH measurements in post-operative axis evaluation.
Rapid tetracosactrin stimulation testing classified patients according to preoperative adrenal integrity. All patients received tapered doses of hydrocortisone beginning on the morning of surgery and discontinued after 48 hours.
Of 28 consecutive patients with various pituitary tumours, 19 completed all aspects of the protocol. All evaluable information from the other 9 was incorporated into the final conclusions and recommendations.
Morning serum cortisol was measured 24 hours after the last hydrocortisone dose. Plasma ACTH and serum cortisol were measured during insulin tolerance testing within 8 days after surgery. Patients received clinical evaluations and repeat testing as clinically indicated during 6-30 months of follow-up.
Both peak serum cortisol > 550 nmol/l and peak plasma ACTH of > 4.4 pmol/l during insulin tolerance testing were 100% sensitive and specific in predicting sustained hypothalamic-pituitary-adrenal axis integrity after surgery. For patients entering surgery with normal tetracosactrin tests, an initial morning serum cortisol > 270 nmol/l provided 100% specificity for preserved axis integrity, but a low cortisol did not indicate axis dysfunction. For patients entering surgery with cortisol deficiency, an initial morning cortisol < 60 nmol/l indicated sustained axis failure, but higher values proved inconclusive. However, the basal cortisol, but not ACTH, on the day of insulin tolerance testing conclusively defined axis status in 18 of 19 study patients (95%).
We conclude that (1) a 48-hour perioperative hydrocortisone reducing regimen may be used in all uncomplicated transsphenoidal pituitary surgery cases regardless of pituitary-adrenal axis status before surgery; (2) preoperative adrenal testing aids interpretation of the initial morning serum cortisol and may be used to direct further testing; (3) a single morning serum cortisol drawn 24 hours after glucocorticoid withdrawal suffices for pituitary-adrenal axis investigation if result suggest no change in axis function, as occurred in most study patients; (4) while insulin tolerance testing 5-8 days after surgery is 100% accurate in determining the need for sustained glucocorticoid replacement due to clinically significant hypopituitarism, repeat morning cortisol measurement obviates provocative testing in 95% of cases; and (5) basal and stimulated plasma ACTH values provide no information additional to serum cortisol measurements in post-operative axis evaluation.
近期数据表明，垂体前叶功能在手术减压后能迅速恢复，经蝶窦垂体手术后无需延迟下丘脑 - 垂体 - 肾上腺轴评估。我们假设一种用于出院前糖皮质激素补充和轴系检查的方案可应用于所有经蝶窦垂体手术患者。该方案探讨了术前检测以及基础和低血糖刺激的皮质醇及促肾上腺皮质激素（ACTH）测量在术后轴系评估中的价值。
快速二十四肽促皮质素刺激试验根据术前肾上腺功能完整性对患者进行分类。所有患者从手术当天早晨开始接受逐渐减量的氢化可的松治疗，并在48小时后停药。
28例连续患有各种垂体肿瘤的患者中，19例完成了方案的所有方面。其他9例患者的所有可评估信息都纳入了最终结论和建议中。
在最后一剂氢化可的松后24小时测量早晨血清皮质醇。术后8天内进行胰岛素耐量试验时测量血浆ACTH和血清皮质醇。患者在6至30个月的随访期间接受临床评估并根据临床指征进行重复检测。
胰岛素耐量试验期间血清皮质醇峰值>550 nmol/l和血浆ACTH峰值>4.4 pmol/l在预测术后下丘脑 - 垂体 - 肾上腺轴持续完整性方面敏感性和特异性均为100%。对于二十四肽促皮质素试验术前正常的患者，初始早晨血清皮质醇>270 nmol/l对轴系完整性保留具有100%的特异性，但皮质醇水平低并不表明轴系功能障碍。对于术前存在皮质醇缺乏的患者，初始早晨皮质醇<60 nmol/l表明轴系持续功能衰竭，但更高的值结果不明确。然而，胰岛素耐量试验当天的基础皮质醇（而非ACTH）在19例研究患者中的18例（95%）中明确界定了轴系状态。
我们得出结论：（1）无论手术前垂体 - 肾上腺轴状态如何，围手术期48小时的氢化可的松减量方案可用于所有无并发症的经蝶窦垂体手术病例；（2）术前肾上腺检测有助于解释初始早晨血清皮质醇，并可用于指导进一步检测；（3）如果结果提示轴系功能无变化，糖皮质激素停药后24小时抽取的单次早晨血清皮质醇足以进行垂体 - 肾上腺轴检查，大多数研究患者均如此；（4）虽然术后5 - 8天的胰岛素耐量试验在确定因临床上显著的垂体功能减退而需要持续糖皮质激素替代方面100%准确，但重复早晨皮质醇测量在95%的病例中可避免激发试验；（5）在术后轴系评估中，基础和刺激后的血浆ACTH值除血清皮质醇测量外无额外信息。
