Alterations in Skin Blood Flow at the Fingertip Are Related to Mortality in Patients With Circulatory Shock

Abstract

Objectives: Skin blood flow is rapidly altered during circulatory shock and may remain altered despite apparent systemic hemodynamic stabilization. We evaluated whether changes in skin blood flow during circulatory shock were related to survival. Design: Prospective study. Setting: Thirty-five-bed medical-surgical university hospital department of intensive care. Subjects: Twenty healthy volunteers and 70 patients with circulatory shock (< 12 hr duration), defined as the need for vasopressors to maintain mean arterial pressure greater than or equal to 65 mm Hg and signs of altered tissue perfusion. Interventions: We assessed skin blood flow using skin laser Doppler on the fingertip for 3 minutes at basal temperature (SBFBT) and at 37°C (SBF37) (thermal challenge test) once in volunteers and at the time of inclusion and after 6, 24, 48, 72, and 96 hours in patients with shock. Capillary refill time and peripheral perfusion index were measured at the same time points on the contralateral hand. Measurements and Main Results: The thermal challenge response (ΔSBF/ΔT) was calculated using the following formula: (SBF37–SBFBT)/(37–basal temperature). Area under the receiver operating characteristic curves were calculated to evaluate variables predictive of ICU mortality. At inclusion, skin blood flow and ΔSBF/ΔT were lower in patients than in volunteers. Baseline skin blood flow (31 [17–113] vs 16 [9–32] arbitrary perfusion units; p = 0.01) and ΔSBF/ΔT (4.3 [1.7–10.9] vs 0.9 [0.4–2.9] arbitrary perfusion unit/s) were greater in survivors than in nonsurvivors. Capillary refill time was shorter in survivors than in nonsurvivors; peripheral perfusion index was similar in the two groups. ΔSBF/ΔT (area under the receiver operating characteristic curve 0.94 [0.88–0.99]) and SBFBT (area under the receiver operating characteristic curve 0.83 [0.73–0.93]) had the best predictive value for ICU mortality with cutoff values less than or equal to 1.25 arbitrary perfusion unit/°C (sensitivity 88%, specificity 89%) and less than or equal to 21 arbitrary perfusion unit (sensitivity 84%, specificity 81%), respectively. Conclusions: Alterations in fingertip skin blood flow can be evaluated using a laser Doppler thermal challenge technique in patients with circulatory shock and are directly related to outcome. These novel monitoring techniques could potentially be used to guide resuscitation.

Dynamic tracking of microvascular hemoglobin content for continuous perfusion monitoring in the intensive care unit: pilot feasibility study

“…Sublingual microcirculation has been evaluated extensively using handheld videomicroscopy [31], and alterations to the microvascular perfusion characteristics are seen following ICU interventions [32][33][34][35], and correlated with adverse ICU outcomes [36,37]. Dynamic assessments of peripheral perfusion using LDF [38,39] or StO2-derived vascular occlusion tests [40,41] also correlate with ICU outcomes, signifying the importance of the microcirculation in the pathophysiology of critical illness.…”

Monitoring skin blood flow to rapidly identify alterations in tissue perfusion during fluid removal using continuous veno-venous hemofiltration in patients with circulatory shock

“…Skin hypoperfusion occurs before systemic hemodynamic variables worsen [9,[21][22][23] and its persistence has been shown to be associated with higher mortality [24][25][26]. Additionally, a shortening of the prolonged capillary refill time (CRT) during resuscitation suggested resolution of tissue hypoperfusion, as reflected by a reduction in lactate concentration [25,[27][28][29].…”

“…Skin laser Doppler (SLD) is a simple noninvasive tool that has been widely used in clinical studies to evaluate cutaneous microcirculatory perfusion [24,26,30]. SLD measures local microcirculatory blood flow including perfusion in capillaries (nutritive flow), arterioles, venules and shunting vessels [31][32][33].…”

“…SLD measures local microcirculatory blood flow including perfusion in capillaries (nutritive flow), arterioles, venules and shunting vessels [31][32][33]. We recently showed that skin blood flow (SBF) measured on the finger using SLD was altered in circulatory shock [26].…”

Correlation between Blood Flow and Temperature of the Ocular Anterior Segment in Normal Subjects

“…When disease develops, the homeostatic balance breaks down. It is well known that the pathophysiology of various systemic diseases such as gingivitis [ 2 ], arteriosclerosis [ 3 , 4 ], and circulatory shock [ 5 ] can be evaluated using temperature and/or blood flow. Similar to other tissues, the ocular anterior segment also adapts when it is exposed to the external environment.…”