Narrative review: clinical assessment of peripheral tissue perfusion in septic shock

Abstract

Sepsis is one of the main reasons for intensive care unit admission and is responsible for high morbidity and mortality. The usual hemodynamic targets for resuscitation of patients with septic shock use macro-hemodynamic parameters (hearth rate, mean arterial pressure, central venous pressure). However, persistent alterations of microcirculatory blood flow despite restoration of macro-hemodynamic parameters can lead to organ failure. This dissociation between macro- and microcirculatory compartments brings a need to assess end organs tissue perfusion in patients with septic shock. Traditional markers of tissue perfusion may not be readily available (lactate) or may take time to assess (urine output). The skin, an easily accessible organ, allows clinicians to quickly evaluate the peripheral tissue perfusion with noninvasive bedside parameters such as the skin temperatures gradient, the capillary refill time, the extent of mottling and the peripheral perfusion index.

Keywords: Capillary refill time; Microcirculation; Mottling; Peripheral perfusion index; Septic shock; Skin; Temperatures gradient.

Fig. 1

Examples of skin microvascular perfusion evaluation using laser Doppler imaging in the knee area according to the mottling score. Skin perfusion decreases when mottling score worsens. Adapted from [9]

Fig. 2

Examples of skin microcirculatory endothelial reactivity in the knee area in a patients with sepsis, in a patient with septic shock that was alive at day 14 and in a patient with septic shock that was ultimately dead at day 14. Skin microcirculatory blood flow was measured at baseline and after acetylcholine iontophoresis. Adapted from [11]

Fig. 3

Proposed strategy to evaluate peripheral tissue perfusion using the skin. CRT capillary refill time, P.Perfusion index peripheral perfusion index

Fig. 4

a The mottling score, ranging from 0 to 5, is based on skin mottling area extension on legs. Score 0 represents no mottling, score 1 represents small mottling area (coin size) localized to the center of the knee, score 2 represents mottling area not exceeding the superior edge of the knee cap, score 3 represents mottling area not exceeding the middle thigh, score 4 represents mottling area not exceeding the fold of the groin and score 5 otherwise. b Example of mottling score 5. Adapted from [37]