Prottengeier Johannes, Moritz Andreas, Heinrich Sebastian, Gall Christine, Schmidt Joachim
Department of Anaesthesiology, Erlangen University Hospital, Krankenhausstrasse 12, 91054, Erlangen, Germany.
Department of Medical Informatics, Biometry and Epidemiology, Waldstrasse 6, 91054, Erlangen, Germany.
Crit Care. 2014 Nov 24;18(6):615. doi: 10.1186/s13054-014-0615-9.
The critically-ill undergoing inter-hospital transfers commonly receive sedatives in continuation of their therapeutic regime or to facilitate a safe transfer shielded from external stressors. While sedation assessment is well established in critical care in general, there is only little data available relating to the special conditions during patient transport and their effect on patient sedation levels. The aim of this prospective study was to investigate the feasibility and relationship of clinical sedation assessment (Richmond Agitation-Sedation Scale (RASS)) and objective physiological monitoring (bispectral index (BIS)) during patient transfers in our Mobile-ICU.
The levels of sedation of 30 pharmacologically sedated patients were evaluated at 12 to 17 distinct measurement points spread strategically over the course of a transfer by use of the RASS and BIS. To investigate the relation between the RASS and the BIS, Spearman's squared rank correlation coefficient (ρ(2)) and the Kendall's rank correlation coefficient (τ) were calculated. The diagnostic value of the BIS with respect to the RASS was investigated by its sensitivity and positive predictive value for possible patient awakening. Therefore, measurements were dichotomized considering a clinically sensible threshold of 80 for BIS-values and classifying RASS values being nonnegative.
Spearman's rank correlation resulted to ρ(2) = 0.431 (confidence interval (CI) = 0.341 to 0.513). The Kendall's correlation coefficient was calculated as τ = 0.522 (CI = 0.459 to 0.576). Awakening of patients (RASS ≥ 0) was detected by a BIS value of 80 and above with a sensitivity of 0.97 (CI = 0.89 to 1.00) and a positive predictive value of 0.59 (CI = 0.45 to 0.71).
Our study demonstrates that the BIS-Monitor can be used for the assessment of sedation levels in the intricate environment of a Mobile-ICU, especially when well-established clinical scores as the RASS are impracticable. The use of BIS is highly sensitive in the detection of unwanted awakening of patients during transfers.
重症患者在院间转运时通常会继续接受镇静治疗，以维持其治疗方案，或在免受外部应激源影响的情况下促进安全转运。虽然一般来说，镇静评估在重症监护中已得到充分确立，但关于患者转运期间的特殊情况及其对患者镇静水平的影响，可用数据很少。这项前瞻性研究的目的是调查在我们的移动重症监护病房（Mobile-ICU）患者转运期间临床镇静评估（里士满躁动镇静量表（RASS））与客观生理监测（脑电双频指数（BIS））之间的可行性及关系。
在转运过程中，通过使用RASS和BIS，在12至17个不同的测量点对30例接受药物镇静的患者的镇静水平进行评估，这些测量点分布在转运过程中。为了研究RASS与BIS之间的关系，计算了斯皮尔曼平方秩相关系数（ρ(2)）和肯德尔秩相关系数（τ）。通过其对患者可能苏醒的敏感性和阳性预测值，研究了BIS相对于RASS的诊断价值。因此，考虑到BIS值80这一临床合理阈值并将RASS值分类为非负，对测量值进行二分法分析。
斯皮尔曼秩相关系数为ρ(2) = 0.431（置信区间（CI）= 0.341至0.513）。肯德尔相关系数计算为τ = 0.522（CI = 0.459至0.576）。BIS值为80及以上时检测到患者苏醒（RASS≥0），敏感性为0.97（CI = 0.89至1.00），阳性预测值为0.59（CI = 0.45至0.71）。
我们的研究表明，BIS监测仪可用于在移动重症监护病房的复杂环境中评估镇静水平，特别是在像RASS这样成熟的临床评分不可行时。在检测转运期间患者意外苏醒方面，BIS的使用具有高度敏感性。
