Infrared Thermography Imaging for Assessment of Peripheral Perfusion in Patients with Septic Shock

Abstract

Skin temperature changes can be used to assess peripheral perfusion in circulatory shock patients. However, research has been limited to point measurements from acral parts of the body. Infrared thermography allows non-invasive evaluation of temperature distribution over a larger surface. Our study aimed to map thermographic patterns in the knee and upper thigh of 81 septic shock patients within 24 h of admission and determine the relationship between skin temperature patterns, mottling, and 28-day mortality. We extracted skin temperature measurements from zones corresponding to mottling scores and used a linear mixed model to analyze the distribution of skin temperature in patients with different mottling scores. Our results showed that the distribution of skin temperature in the anterior thigh and knee is physiologically heterogeneous and has no significant association with mottling or survival at 28 days. However, overall skin temperature of the anterior thigh and knee is significantly lower in non-survivors when modified by mottling score. No differences were found in skin temperature between the survivor and non-survivor groups. Our study shows the potential usefulness of infrared thermography in evaluating skin temperature patterns in resuscitated septic shock patients. Overall skin temperature of the anterior thigh and knee may be an important indicator of survival status when modified by mottling score.

Keywords: circulatory shock; infrared thermography; lower limb; peripheral perfusion; sepsis; skin temperature.

Figure 1

(A,B) Thermographic images of anterior thigh and knee; (C) thermographic image of the dorsal aspect of the foot; (D,E) temperature measurement zones defined to match mottling scores 1 to 4, Zone I, coin-sized area located in the center of patella, Zone II, area over the entire patella, Zone III, area up to the middle of upper leg, and Zone IV, area up to the inguinal fold; (F) temperature measurement zone on the toe.

Figure 2

Skin temperature variation among septic shock patients by mottling score and measurement zone. (a) Skin temperature by measurement zone with significant model effects; (b) skin temperature by mottling score with significant model effects. Observations lying beyond 1.5 times the interquartile range are shown as black dots. Full model results are shown in Supplemental Table S1.

Figure 3

Variation in skin temperature among patients with septic shock by mottling score and survival status at 28 days with significant model effects. Asterisks denote significant interaction: * p < 0.05. Observations lying beyond 1.5 times the interquartile range are shown as black dots. Full model results are shown in Supplemental Table S2.