Department of Emergency Medicine, UMDNJ-Robert Wood Johnson Medical School at Camden, Cooper University Hospital, One Cooper Plaza, Camden, NJ 08103, USA.
Intensive Care Med. 2009 Oct;35(10):1761-6. doi: 10.1007/s00134-009-1517-1. Epub 2009 Jun 24.
Sublingual microvascular videomicroscopy can assess tissue perfusion in critically ill patients; however, data analysis is currently limited to delayed off-line evaluation. We hypothesized that a real-time point-of-care (POC) determination of the microcirculatory flow index (MFI), an established metric for assessing microcirculatory perfusion, agrees well with the conventional off-line analysis.
Prospective observational study.
Urban academic intensive care unit.
A heterogeneous population of critically ill patients.
A single operator performed side stream darkfield videomicroscopy of the sublingual microcirculation and made a POC determination of MFI in real-time on a portable bedside monitor by assigning a score (0 = no flow to 3 = normal) to each quadrant of the image and averaging the four values. After image processing, de-identification and randomization, the same operator, blinded to the previous interpretation, repeated the MFI assessment by viewing an AVI-formatted image sequence on a 94 cm 1,080 pixel LCD monitor (reference standard). There were 205 paired measurements in 18 subjects. The POC and reference standard MFI had good agreement by Bland-Altman analysis [mean difference of -0.031, SD = 0.198 (95% CI, -0.43 to 0.37)]. The POC assessment was 94% sensitive and 92% specific for detecting impaired microvascular flow (defined a priori as an MFI < 2.5 based on previously published data).
A POC determination of MFI had good agreement with conventional off-line analysis, and was highly sensitive and specific for detecting impaired microvascular flow. This real-time technique may be useful in future clinical trials targeting impaired microcirculatory perfusion in critically ill patients.
舌下微血管视频显微镜可评估危重病患者的组织灌注情况；然而，数据分析目前仅限于延迟的离线评估。我们假设，一种实时的床边即时检测（POC）方法可以准确地确定微循环血流指数（MFI），这是评估微循环灌注的一种既定指标。
前瞻性观察性研究。
城市学术性重症监护病房。
来自不同背景的危重病患者。
一名操作人员对舌下微循环进行侧流暗场视频显微镜检查，并通过对图像的每个象限分配一个分数（0=无血流至 3=正常），然后将四个象限的平均值作为实时 POC 测定的 MFI 值，在便携式床边监视器上进行实时测量。在图像处理、去识别和随机化之后，同一名操作人员在查看 94 厘米 1080 像素的液晶显示器（参考标准）上的 AVI 格式图像序列时，对 MFI 进行重复评估，但不了解之前的解释。18 名受试者中有 205 对测量结果。通过 Bland-Altman 分析，POC 和参考标准 MFI 具有良好的一致性[平均差值为-0.031，SD=0.198（95%可信区间，-0.43 至 0.37）]。POC 评估对于检测微血管血流受损（基于先前发表的数据，定义为 MFI<2.5）具有 94%的敏感性和 92%的特异性。
POC 测定 MFI 与传统的离线分析具有良好的一致性，并且对于检测微血管血流受损具有高度的敏感性和特异性。这种实时技术可能对未来针对危重病患者受损微循环灌注的临床试验有用。
