Alteration of skin perfusion in mottling area during septic shock

Abstract

BackgroundMottling score has been reported to be a strong predictive factor during septic shock. However, the pathophysiology of mottling remains unclear.MethodsIn patients admitted in ICU for septic shock, we measured on the same area the mean skin perfusion by laser Doppler, the mottling score, and variations of both indices between T1 (6 hours after vasopressors were started) and T2 (24 hours later).ResultsFourteen patients were included, SAPS II was 56 [37–71] and SOFA score at T1 was 10 [7–12]. The mean skin surface area analyzed was 4108 ± 740 mm2; 1184 ± 141 measurements were performed over each defined skin surface area. Skin perfusion was significantly different according to mottling score and decreased from 37 [31–42] perfusion units (PUs) for a mottling score of [0–1] to 22 [20–32] PUs for a mottling score of [2–3] and 23 [16–28] for a score of [4–5] (Kruskal-Wallis test, P = 0.05). We analyzed skin perfusion changes during resuscitation in each patient and together with mottling score variations between T1 and T2 using a Wilcoxon signed-rank test. Among the 14 patients included, mottling score increased (worsened) in 5 patients, decreased (improved) in 5 patients, and remained stable in 4 patients. Baseline skin perfusion at T1 was arbitrarily scored 100%. Mean skin perfusion significantly decreased in all the patients whose mottling score worsened from 100% baseline to 63.2 ± 10.7% (P = 0.001), mean skin perfusion significantly increased in all patients whose mottling score improved from 100% baseline to 172.6 ± 46.8% (P = 0.001), and remained stable in patients whose mottling score did not change (100.5 ± 6.8%, P = 0.95).ConclusionsWe have shown that mottling score variations and skin perfusion changes during septic shock resuscitation were correlated, providing additional evidence that mottling reflects skin hypoperfusion.

Microcirculatory disorders during septic shock

“…Several authors have shown that adjusting norepinephrine doses gradually, to achieve a MAP of 75 and then 85 mmHg, was beneficial in some patients, but frankly deleterious in others [12,15]. Likewise, the administration of norepinephrine improved small-vessel perfusion in some but not all patients [15,16]. These studies demonstrated that although a minimal threshold MAP is required to perfuse tissues, it is not sufficient to normalize the microcirculatory perfusion.…”

Exploration of skin perfusion in cirrhotic patients with septic shock

“…This technique has already been reported to assess skin perfusion alterations in non-cirrhotic patients with septic shock [12]. Laser light penetrates the tissue and is scattered and partly absorbed.…”

“…During the last years, microcirculation alterations were established as the main cause of organ failure and death [8,9] and their persistence, despite global hemodynamic resuscitation, is an earlier and stronger predictor of outcome than global hemodynamic variables [10]. Among the tools developed to assess microcirculation alteration at the bedside, we recently developed a clinical score, called the mottling score, evaluating skin perfusion [11,12]. This simple and reproducible score clinically quantifies the mottling area extension around the knee.…”

Reply to: “Is skin mottling a predictor of high mortality in non-selected patients with cirrhosis admitted to intensive care unit?”

“…Assessment of mottling prognosis value perfectly illustrates this point. Mottling is defined as patchy skin discoloration that usually starts around the knees due to heterogenic small vessel vasoconstriction, reflecting abnormal skin microperfusion [1]. More than 45 years ago, mottling was frequently noticed in patients with septic shock [2].…”