Increased tissue water in patients with severe sepsis affects tissue oxygenation measured by near-infrared spectroscopy: a prospective, observational case-control study

Abstract

Background: Tissue oedema affects tissue perfusion and interferes with the monitoring of tissue oxygenation in patients with severe sepsis. However, the underlying mechanisms remain unclear. We used a wireless near-infrared spectroscopy (NIRS) device that transmits tri-wavelength light to quantify tissue haemoglobin (Hb) and water (H 2 O) content. We estimated tissue H 2 O in severe sepsis patients and healthy controls, compared their difference, and investigated the correlation of tissue H 2 O with systemic haemodynamics and its impact on tissue oxygenation.Methods: Seventy-seven adult patients with new-onset severe sepsis admitted to the intensive care unit within 72 h and 30 healthy volunteers (controls) were enrolled. The NIRS device was placed on the participant's leg to estimate the relative tissue concentrations of oxy-Hb ([HbO 2 ]), deoxy-Hb ([HbR]), total Hb ([HbT]), and H 2 O ([H 2 O]) at rest for three consecutive days. Two-sample t-test or Mann-Whitney U test, chi-square test, and generalised estimating equations (GEEs) were used for comparisons.Results: In severe sepsis patients, the [H 2 O] in the anterior tibia was higher [mean (standard deviation, 95%

Serum vascular endothelial growth factor independently affects tissue fluid accumulation and is related to deteriorating tissue perfusion and oxygenation in severe sepsis: a prospective observational study

“…Understanding the state of tissue uid is necessary to prevent the harm of uid overload on microcirculation and may guide uid therapy and prevent liberal uid administration. To estimate the accumulated tissue uid, we developed a NIRS device to detect tissue H 2 O and found that [H 2 O] was signi cantly higher in patients with severe sepsis than in healthy controls (21). In the present research, we discovered that oliguric patients with severe sepsis had more positive uid balance and gradually accumulated H 2 O in the tissues.…”

“…Adult patients (aged ≥ 18 years) who were transferred to the ICU from the emergency department and admitted within 72 h for new-onset severe sepsis were enrolled. The detailed eligibility criteria were described in our previous report (21). After signing the informed consent, the patients were assessed with a non-invasive wireless NIRS device, which is still investigational, for three consecutive days.…”

“…The sample size estimate for the initial observational study was based on our previous study of comparisons of NIRS parameters between patients and controls (21).…”

“…However, increased vascular permeability and tissue edema due to sepsis-related endothelial dysfunction may affect StO 2 assessment (20). Our previous study has identi ed an inverse relationship between tissue water (H 2 O) and StO 2 estimated using NIRS in patients with severe sepsis (21). We hypothesized that increased serum VEGF in patients with sepsis leads to the accumulation of tissue uid and is associated with tissue hypoperfusion.…”

Reference Values of Regional Oxygen Saturation (rSO2) Determined by Near-Infrared Spectroscopy (NIRS) for 18 Selected Regions of Interest (ROIs) in Young and Elderly Healthy Volunteers

“…There is also a constantly growing interest among researchers in the possibility of using NIRS in monitoring changes in muscle oxygenation and blood flow during physiological and pathological conditions, e.g., during submaximal and maximum exercise [13,[20][21][22], to identify peripheral vascular disease [23], in chronic obstructive pulmonary disease (COPD) [24], in cardiovascular diseases [25] and in sepsis [26]. It has been found that during work the degree of deoxidation of skeletal muscles varies depending on the type of muscle, type of exercise and blood flow specific to a given area and health status [27,28].…”