Peripheral Muscle Near-Infrared Spectroscopy Variables are Altered Early in Septic Shock.

Abstract

BACKGROUND:

Noninvasive evaluation of muscle perfusion using near-infrared spectroscopy (NIRS) coupled with a vascular occlusion test (VOT) may provide an early and simple marker of altered perfusion and microcirculatory function in sepsis.

OBJECTIVE:

The aim of the study was to compare the time-course of NIRS-derived variables with systemic measures of perfusion in an experimental model of peritonitis.

METHODS:

Peritonitis was induced in eight anesthetized, mechanically ventilated, adult sheep (24-34 kg), by injecting autologous feces into the peritoneal cavity. Animals were followed until death or for a maximum of 30 h. Muscle tissue oxygen saturation (StO2) was determined using NIRS on the right posterior leg and arterial VOTs were performed by intermittent intra-aortic balloon inflation. Microdialysis was used to measure muscle lactate and pyruvate levels.

RESULTS:

Muscle StO2 was significantly lower than baseline values from 8 h after sepsis induction, but with considerable intersubject variability. The NIRS VOT ascending (Asc) slope decreased to values <120%/min in most animals from 12 h after sepsis induction. Muscle lactate/pyruvate ratios were higher than baseline from 16 h after sepsis induction. Mixed venous oxygen saturation (SvO2) decreased to <70% and blood lactate levels increased to >2 mmol/L in most of the animals only 24 and 28 h after sepsis induction, respectively. Muscle NIRS StO2 correlated strongly with femoral venous oxygen saturation (r = 0.820) and moderately with SvO2 (r = 0.436).

CONCLUSIONS:

The muscle NIRS Asc slope after a VOT is altered earlier than global markers of tissue hypoperfusion during sepsis. This simple noninvasive test can detect early changes in peripheral perfusion in sepsis.

• Authors: Diego Orbegozo, Fuhong Su, Keliang Xie, Lokmane Rahmania, Fabio Silvio Taccone, Daniel De Backer, Jean-Louis Vincent, Jacques Creteur
• Journal: Shock (Augusta, Ga.) (Shock) Vol. 50 Issue 1 Pg. 87-95 (07 2018) ISSN: 1540-0514 [Electronic] United States
• PMID: 28930916 (Publication Type: Journal Article)

Chemical References

• Lactates
• Pyruvic Acid

Topics

• Animals
• Female
• Lactates (metabolism)
• Microcirculation (physiology)
• Muscle, Skeletal (metabolism)
• Oxygen Consumption (physiology)
• Pyruvic Acid (metabolism)
• Sheep
• Shock, Septic (metabolism, physiopathology)
• Spectroscopy, Near-Infrared (methods)