Kildal Anders Benjamin, Stenberg Thor Allan, Sanden Espen, Myrmel Truls, How Ole-Jakob
Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; Department of Cardiothoracic and Vascular Surgery, Heart and Lung Clinic, University Hospital of North Norway, Tromsø, Norway
Cardiovascular Research Group, Department of Clinical Medicine, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway; Department of Cardiothoracic and Vascular Surgery, Heart and Lung Clinic, University Hospital of North Norway, Tromsø, Norway.
J Appl Physiol (1985). 2015 Apr 15;118(8):965-70. doi: 10.1152/japplphysiol.00900.2014. Epub 2015 Feb 12.
Intravital videomicroscopy of sublingual microcirculation is used to monitor critically ill patients. Existing guidelines suggest averaging handheld video recordings of ∼20 s in duration from five areas. We assessed whether an extended observation time may provide additional information on the microcirculation. Pigs (n = 8) under general anesthesia were divided between two groups, one with manually held camera, in which microcirculation was assessed continuously for 1 min in five areas, and one with a fixed camera, in which the observation time was extended to 10 min in a single area. The microcirculation was challenged by infusing arginine vasopressin (AVP). In the fixed group, ischemic acute heart failure was induced by left coronary microembolization, and the AVP infusion was repeated. All recordings were divided into 20-s sequences, and the small-vessel microvascular flow index (MFI) was scored and averaged for each measurement point. When administering 0.003, 0.006, and 0.012 IU·kg(-1)·min(-1) of AVP, we observed that the small-vessel MFI in the fixed 10-min group was significantly reduced (2.03 ± 0.38, 0.98 ± 0.18, and 0.48 ± 0.11) compared with both the initial 20 s (2.77 ± 0.04, 2.06 ± 0.04, and 1.74 ± 0.06; P < 0.05) and the 1-min total (2.63 ± 0.09, 1.70 ± 0.07, and 1.33 ± 0.16; P < 0.05) in the handheld group. In acute heart failure, the cardiac output decreased to half of the preischemic values. Interestingly, the small-vessel MFI was more affected by the administration of 0.001 and 0.003 IU·kg(-1)·min(-1) of AVP in acute heart failure (1.62 ± 0.60 and 1.16 ± 0.38) compared with preischemic values (2.86 ± 0.09 and 2.03 ± 0.38; P < 0.05). In conclusion, a prolonged recording time reveals temporal heterogeneity that may impact the assessment of microcirculatory function.
舌下微循环的活体视频显微镜检查用于监测危重症患者。现有指南建议从五个区域对时长约20秒的手持视频记录求平均值。我们评估了延长观察时间是否能提供关于微循环的更多信息。将处于全身麻醉状态的猪（n = 8）分为两组，一组使用手持相机，在五个区域连续评估微循环1分钟，另一组使用固定相机，在单个区域将观察时间延长至10分钟。通过输注精氨酸加压素（AVP）对微循环进行挑战。在固定组中，通过左冠状动脉微栓塞诱导缺血性急性心力衰竭，并重复输注AVP。所有记录均分为20秒的序列，并对每个测量点的小血管微血管血流指数（MFI）进行评分和求平均值。当给予0.003、0.006和0.012 IU·kg⁻¹·min⁻¹的AVP时，我们观察到固定10分钟组的小血管MFI与手持组最初的20秒（2.77 ± 0.04、2.06 ± 0.04和1.74 ± 0.06；P < 0.05）以及1分钟的总和（2.63 ± 0.09、1.70 ± 0.07和1.33 ± 0.16；P < 0.05）相比显著降低（2.03 ± 0.38、0.98 ± 0.18和0.48 ± 0.11）。在急性心力衰竭中，心输出量降至缺血前值的一半。有趣的是，与缺血前值（2.86 ± 0.09和2.03 ± 0.38；P < 0.05）相比，急性心力衰竭中给予0.001和0.003 IU·kg⁻¹·min⁻¹的AVP时，小血管MFI受影响更大（1.62 ± 0.60和1.16 ± 0.38）。总之，延长记录时间可揭示可能影响微循环功能评估的时间异质性。
