Department of Anesthesiology and Critical Care, Brigham and Women's Hospital, Boston, MA, USA.
Tufts University School of Medicine, Boston, MA, USA.
Br J Anaesth. 2017 Aug 1;119(2):324-332. doi: 10.1093/bja/aex103.
Delirium is common after surgery, although the aetiology is poorly defined. Brain-derived neurotrophic factor (BDNF) is a neurotrophin important in neurotransmission and neuroplasticity. Decreased levels of BDNF have been associated with poor cognitive outcomes, but few studies have characterized the role of BDNF perioperatively. We hypothesized that intraoperative decreases in BDNF levels are associated with postoperative delirium.
Patients undergoing spine surgery were enrolled in a prospective cohort study. Plasma BDNF was collected at baseline and at least hourly intraoperatively. Delirium was assessed using rigorous methods, including the Confusion Assessment Method (CAM) and CAM for the intensive care unit. Associations of changes in BDNF and delirium were examined using regression models.
Postoperative delirium developed in 32 of 77 (42%) patients. The median baseline BDNF level was 7.6 ng ml -1 [interquartile range (IQR) 3.0-11.2] and generally declined intraoperatively [median decline 61% (IQR 31-80)]. There was no difference in baseline BDNF levels by delirium status. However, the percent decline in BDNF was greater in patients who developed delirium [median 74% (IQR 51-82)] vs in those who did not develop delirium [median 50% (IQR 14-79); P =0.03]. Each 1% decline in BDNF was associated with increased odds of delirium in unadjusted {odds ratio [OR] 1.02 [95% confidence interval (CI) 1.00-1.04]; P =0.01}, multivariable-adjusted [OR 1.02 (95% CI 1.00-1.03); P =0.03], and propensity score-adjusted models [OR 1.02 (95% CI 1.00-1.04); P =0.03].
We observed an association between intraoperative decline in plasma BDNF and delirium. These preliminary results need to be confirmed but suggest that plasma BDNF levels may be a biomarker for postoperative delirium.
手术后谵妄很常见，但其病因尚不清楚。脑源性神经营养因子（BDNF）是一种在神经传递和神经可塑性中起重要作用的神经营养因子。BDNF 水平降低与认知功能不良有关，但很少有研究描述围手术期 BDNF 的作用。我们假设术中 BDNF 水平下降与术后谵妄有关。
接受脊柱手术的患者被纳入前瞻性队列研究。在基线和术中至少每小时采集血浆 BDNF。使用严格的方法评估谵妄，包括意识混乱评估方法（CAM）和重症监护病房的 CAM。使用回归模型检查 BDNF 变化与谵妄的相关性。
77 例患者中有 32 例（42%）发生术后谵妄。BDNF 的中位基线水平为 7.6ng/ml[四分位距（IQR）3.0-11.2]，术中一般呈下降趋势[中位数下降 61%（IQR 31-80%）]。谵妄状态下的 BDNF 基线水平无差异。然而，发生谵妄的患者 BDNF 的下降幅度更大[中位数 74%（IQR 51-82%）]，而未发生谵妄的患者下降幅度较小[中位数 50%（IQR 14-79%）；P=0.03]。BDNF 每下降 1%，未校正时发生谵妄的可能性增加[优势比（OR）1.02[95%置信区间（CI）1.00-1.04]；P=0.01]，多变量校正时增加[OR 1.02（95%CI 1.00-1.03）；P=0.03]，倾向评分校正时也增加[OR 1.02（95%CI 1.00-1.04）；P=0.03]。
我们观察到术中 BDNF 下降与谵妄之间存在关联。这些初步结果需要进一步证实，但提示血浆 BDNF 水平可能是术后谵妄的生物标志物。
