Burns Trauma and Critical Care Research Centre, University of Queensland, Herston 4006, Australia.
Crit Care. 2009;13(6):R189. doi: 10.1186/cc8184. Epub 2009 Nov 27.
The assessment of adrenal function in critically ill patients is problematic, and there is evidence to suggest that measurement of tissue glucocorticoid activity may be more useful than estimation of plasma cortisol concentrations. Interstitial cortisol concentrations of cortisol represent the available pool of glucocorticoids able to enter the cell and bind to the glucocorticoid receptor. However the concentrations of plasma cortisol may not accurately reflect interstitial concentrations. We elected to perform a preliminary study into the feasibility of measuring interstitial cortisol by microdialysis, and to investigate the relationship between total plasma cortisol, free plasma cortisol and interstitial cortisol in patients with severe burns.
A prospective observational study carried out in a tertiary intensive care unit. Ten adult patients with a mean total burn surface area of 48% were studied. Interstitial cortisol was measured by microdialysis from patient-matched burnt and non-burnt tissue and compared with that of 3 healthy volunteers. Plasma sampling for estimations of total and free cortisol concentrations was performed concurrently.
In the burn patients, mean total plasma and free plasma cortisol concentrations were 8.8 +/- 3.9, and 1.7 +/- 1.1 mcg/dL, (p < 0.001), respectively. Mean subcutaneous microdialysis cortisol concentrations in the burn and non-burn tissue were 0.80 +/- 0.31 vs 0.74 +/- 0.41 mcg/dL (p = 0.8), respectively, and were significantly elevated over the mean subcutaneous microdialysis cortisol concentrations in the healthy volunteers. There was no significant correlation between total plasma or free plasma and microdialysis cortisol concentrations. Plasma free cortisol was better correlated with total burn surface area than total cortisol.
In this preliminary study, interstitial cortisol concentrations measured by microdialysis in burnt and non-burnt skin from patients with severe thermal injury are significantly elevated over those from healthy volunteers. Plasma estimations of cortisol do not correlate with the microdialysis levels, raising the possibility that plasma cortisol may be an unreliable guide to tissue cortisol activity.
在危重病患者中评估肾上腺功能存在问题，有证据表明，测量组织糖皮质激素活性可能比估计血浆皮质醇浓度更有用。皮质醇的间质皮质醇浓度代表能够进入细胞并与糖皮质激素受体结合的可用糖皮质激素库。然而，血浆皮质醇浓度可能无法准确反映间质浓度。我们选择进行一项初步研究，通过微透析测量间质皮质醇的可行性，并研究严重烧伤患者的总血浆皮质醇、游离血浆皮质醇和间质皮质醇之间的关系。
在三级重症监护病房进行的前瞻性观察性研究。研究了 10 名平均总烧伤面积为 48%的成年患者。通过微透析从患者匹配的烧伤和非烧伤组织中测量间质皮质醇，并与 3 名健康志愿者进行比较。同时进行血浆采样以估计总皮质醇和游离皮质醇浓度。
在烧伤患者中，总血浆和游离血浆皮质醇浓度分别为 8.8 +/- 3.9 和 1.7 +/- 1.1 mcg/dL（p < 0.001）。烧伤和非烧伤组织中皮下微透析皮质醇浓度分别为 0.80 +/- 0.31 与 0.74 +/- 0.41 mcg/dL（p = 0.8），均显著高于健康志愿者的皮下微透析皮质醇浓度。总血浆或游离血浆与微透析皮质醇浓度之间无显著相关性。游离血浆皮质醇与总烧伤面积的相关性优于总皮质醇。
在这项初步研究中，严重热损伤患者烧伤和非烧伤皮肤的微透析测量的间质皮质醇浓度明显高于健康志愿者。皮质醇的血浆估计值与微透析水平不相关，这表明血浆皮质醇可能是组织皮质醇活性的不可靠指标。
Zotero 插件