Patel Nathan T P, Templeton T Wesley, Lane Magan R, Williams Timothy K, Neff Lucas P, Goenaga-Diaz Eduardo J
Department of Surgery, Wake Forest Baptist Medical Center, Winston-Salem, NC.
Department of Anesthesiology, Wake Forest Baptist Medical Center, Winston-Salem, NC.
Crit Care Explor. 2022 Aug 15;4(8):e0749. doi: 10.1097/CCE.0000000000000749. eCollection 2022 Aug.
Near infrared spectroscopy (NIRS) is a noninvasive tool for assessing local oxygen balance. In circulatory shock, the microcirculatory environment as measured by NIRS during resuscitation may provide additional diagnostic tools of value to the critical care physician.
To assess whether a relative increase in peripheral NIRS was correlated with a clinically relevant increase in cardiac output following a fluid bolus in a swine model of shock.
Nine healthy young adult swine with median weight 80 kg (interquartile range, 75-83 kg) were anesthetized and surgically instrumented. They underwent a controlled hemorrhage of 20% of their blood volume followed by partial or complete aortic occlusion to create a variable ischemia-reperfusion injury. Next, the animals underwent four 500-mL plasmalyte boluses over 9 minutes each followed by a 6-minute pause. The animal then underwent a 25% mixed auto/homologous blood transfusion followed by four more 500 mL plasmalyte boluses over 9 minutes. Finally, the animals underwent a 25% mixed auto/homologous blood transfusion followed by an additional four rounds of 500-mL plasmalyte boluses over 9 minutes. Left thoracic limb NIRS, descending thoracic aortic flow (dAF), arterial blood pressure (MAP), central venous pressure (CVP), and mixed central venous oxygen saturation (Svo) were measured continuously for comparison.
The area under the receiver operating curve for an increase in dAF of 10% in response to a 500 mL bolus based on a percent increase in the proximal NIRS was 0.82 with 95% CI, 0.72-0.91; Svo, 0.86 with 95% CI, 0.78-0.95; MAP, 0.75 with 95% CI, 0.65-0.85 and CVP, 0.64 with 95% CI, 0.53-0.76.
A dynamic relative increase in NIRS in response to a crystalloid challenge has moderate discriminatory power for cardiac output augmentation during shock in a swine model of ischemia-reperfusion injury. NIRS performed as well as invasive measurements (Svo and MAP) and better than CVP.
近红外光谱（NIRS）是一种用于评估局部氧平衡的非侵入性工具。在循环性休克中，复苏期间通过NIRS测量的微循环环境可能为重症监护医生提供有价值的额外诊断工具。
评估在休克猪模型中，给予液体推注后外周NIRS的相对增加是否与心输出量的临床相关增加相关。
9只体重中位数为80 kg（四分位间距，75 - 83 kg）的健康年轻成年猪被麻醉并进行手术器械植入。它们经历了20%血容量的控制性出血，随后进行部分或完全主动脉阻断以造成可变的缺血 - 再灌注损伤。接下来，动物在9分钟内每次接受4次500 mL的血浆代用品推注，随后暂停6分钟。然后动物接受25%的自体/同源混合输血，接着在9分钟内再进行4次500 mL的血浆代用品推注。最后，动物接受25%的自体/同源混合输血，随后在9分钟内再进行4轮500 mL的血浆代用品推注。持续测量左胸肢NIRS、降主动脉血流量（dAF）、动脉血压（MAP）、中心静脉压（CVP）和混合中心静脉血氧饱和度（Svo）以进行比较。
基于近端NIRS的百分比增加，对500 mL推注做出反应时dAF增加10%的受试者工作特征曲线下面积为0.82，95%置信区间为0.72 - 0.91；Svo为0.86，95%置信区间为0.78 - 0.95；MAP为0.75，95%置信区间为0.65 - 0.85；CVP为0.64，95%置信区间为0.53 - 0.76。
在缺血 - 再灌注损伤的猪模型休克期间，对晶体液激发的反应中NIRS的动态相对增加对心输出量增加具有中等鉴别能力。NIRS的表现与侵入性测量（Svo和MAP）相当，且优于CVP。
