Please see Bibliography of References for a list of abstracts, manuscripts and posters.

Other Studies

Use of StO₂ in association with skin temperature as an indicator of the peripheral tissue perfusion in critically ill patients

Lima A, Ince C, Bakker J. Crit Care. 2009;13(Suppl 1):P236.

Introduction: Studies have suggested that StO₂ values are insensitive in assessing peripheral perfusion. StO₂ measurements may be more correctly interpreted if measured in association with forearm-to-fingertip skin-temperature gradient (Tskin-diff). A Tskin-diff threshold of 0ºC has been showed to reflect vasoconstriction. We aimed to propose a different approach for the interpretation of StO₂ by adding Tskin-diff monitoring and to characterize the pattern of StO₂ dynamic in patients with peripheral vasoconstriction and vasodilation. We hypothesize that monitoring StO₂ with Tskin-diff can more adequately predict ICU complications than StO₂ itself.

Methods: StO₂ was continuously monitored on the thenar with InSpectra Model 325 probe (Hutchinson Technology Inc.). The Tskin-diff was obtained from two skin probes (Hewlett Packard 21078A) attached to the index finger and on the radial side of the forearm. To describe the effect of variations in skin temperature on StO₂, we compared StO₂ in survivors and nonsurvivors stratified by the condition of peripheral circulation (vasoconstriction, Tskin-diff>0; vasodilation, Tskin-diff<0). The first measurement was registered within 24 hours and every 24 h until day 3. Differences between group means were tested by Mann-Whitney U test. P values <0.05 were considered statistically significant.

Results: We prospectively studied 41 consecutive critically ill patients (survivor=29; nonsurvivor=12): age: 49±16; 20 septic shock, 14 nonseptic shock, 7 other. No differences in StO₂ was seen between survivor and nonsurvivors (Day 1: 73±9 vs. 78±10; Day 2: 74±11 vs. 75±11; Day 3: 76±10 vs. 77±9). In survivors, StO₂ values were significantly lower in peripheral vasoconstriction than in vasodilation (Day 1: 69±8 vs. 76±8; Day 2: 68±13 vs. 78±7; Day 3: 71±10 vs. 80±9; P<0.05). In nonsurvivors, this association was seen only on day 1 (71±8 vs. 86±4; P<0.05). Compared to survivors on day 3, nonsurvivors had lower StO₂ values in peripheral vasodilation (69±6 vs. 80±9, P=0.02) and higher StO₂ values in peripheral vasoconstriction (83±7 vs. 71±10, P=0.02).

Conclusions: Dissociation between StO₂ and skin temperature was seen more often in nonsurvivors. StO₂ measured in association with skin temperature can more adequately predict ICU death than StO₂ itself.

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