Usefulness of Platelet-to-Lymphocyte Ratio as a Marker of Sarcopenia for Critical Limb Threatening Ischemia.

BACKGROUND: Sarcopenia is a factor of poor prognosis for patients with critical limb threatening ischemia (CLTI), but its diagnosis requires imaging measurements and is time consuming. We investigated whether preoperative platelet-to-lymphocyte ratio (PLR) could be an easy and rapid marker of sarcopenia. METHODS: Patients treated for CLTI between January 2019 and July 2019 were included in this single-center retrospective study. Sarcopenia was defined by a psoas muscle index (PMI) <5.5 cm2/m2 in men, and <4.0 cm2/m2 in women. PLR was calculated for all patients based on their systematic preoperative blood analysis. The diagnostic power of PLR was analyzed through a receiver operating characteristic (ROC) curve. Early outcomes of sarcopenic patients in terms of 30-day mortality and 30-day morbidity were retrieved. RESULTS: Sixty-four patients were included in the study: 48 nonsarcopenic patients (mean PMI 7.34 cm2/m2; interquartile range [IQR] 6.58-8.01) and 16 sarcopenic patients (mean PMI 4.30 cm2/m2; IQR 3.45-5.17). No difference was found between both groups regarding patient demographics, clinical characteristics, cardiovascular risk factors, comorbidities, or revascularization modalities. PLR was significantly higher in the sarcopenic group (mean 332.1; IQR 158.2-320.7) compared with the nonsarcopenic group (mean 204.6; IQR 133.8-265.6) (P = 0.02). A PLR value ≥292.5 was shown to be a diagnostic marker for sarcopenia based on the ROC curve (sensitivity 31.3%, specificity 91.7%). Thirty-day mortality was 12.5% in the sarcopenic group and 2.1% in the nonsarcopenic group (P = 0.15); 30-day morbidity was 56.3% in the sarcopenic group and 10.4% in the nonsarcopenic group (P < 0.001). CONCLUSIONS: PLR might help identifying a subgroup of CTLI patients associated with poor prognosis but does not seem appropriate to be used as a marker of sarcopenia given its low sensitivity.

Comparative analysis of resuscitation using human serum albumin and crystalloids or 130/0.4 hydroxyethyl starch and crystalloids on skeletal muscle metabolic profile during experimental haemorrhagic shock in swine: A randomised experimental study.

BACKGROUND: Protection against acute skeletal muscle metabolic dysfunction and oxidative stress could be a therapeutic target in volume expansion for severely bleeding patients. OBJECTIVES: This experimental pilot study in swine aims at comparing 130/0.4 hydroxyethyl starch (HES) with 4% albumin along with crystalloid perfusion for first-line volume expansion in haemorrhagic shock with a particular emphasis on oxidative stress and muscular mitochondrial function. DESIGN: Randomised experimental study. SETTING: Digestive Cancer Research Institute Preclinical Laboratory, Strasbourg University Hospital, France, from February 2012 to June 2013. ANIMALS: Twenty large white pigs. INTERVENTION: Pressure-controlled haemorrhagic shock and volume resuscitation using either 4% human serum albumin or 130/0.4 HES along with crystalloid perfusion were performed in 20 large white pigs. MAIN OUTCOME MEASURES: Muscular biopsy of gastrocnemius muscle was performed for metabolomics screening, mitochondrial respiratory chain assessment and electron spin resonance reactive oxygen species production along with arterial and venous reactive oxygen species production at baseline, at the completion of shock, at 90 min and at 180 min after volume expansion. RESULTS: There was no difference between the two groups in measurements of skeletal muscle superoxide production. In a pooled analysis, there was a statistically significant decrease in gastrocnemius muscle creatine content from baseline to 90 min (P < 0.05) and 180 min (P < 0.05). Muscular lactate content and mitochondrial respiratory chain oxidative capacity remained constant at the respective time points. CONCLUSION: In this pilot experimental study in swine, during pressure-controlled haemorrhagic shock treated with either albumin or 130/0.4 HES in conjunction with crystalloid perfusion, skeletal muscle metabolic profile was unaltered. ETHICAL APPROVAL NUMBER: 38.2012.01.031.

Remote and local ischemic postconditioning further impaired skeletal muscle mitochondrial function after ischemia-reperfusion.

OBJECTIVE: Muscular injuries contribute to perioperative and long-term morbidity after vascular surgery in humans. We determined whether local and remote ischemic postconditioning might similarly decrease muscle mitochondrial dysfunction through reduced oxidative stress. METHODS: Eighteen male Black-6 mice were divided in three groups: (1) sham mice had no ischemia (sham), (2) ischemia-reperfusion (IR) mice underwent 2-hour tourniquet-induced ischemia on both hind limbs, followed by 2-hour reperfusion, and (3) postconditioning (PoC) mice underwent four bouts of 30-second reperfusion and 30-second ischemia at the onset of reperfusion on the right limb; thus, the right limb underwent local PoC and left limb underwent remote PoC (rPoC). Maximal oxidative capacity (V(max)) of the gastrocnemius muscle mitochondrial respiratory chain was measured. Oxidative stress was evaluated by dihydroethidium staining. Expressions of genes involved in antioxidant defense (superoxide dismutase [SOD1], SOD2, glutathione peroxidase [GPx]), apoptosis (Bax, BclII), and inflammation (interleukin-6) were determined by quantitative real-time polymerase chain reaction. Muscle inflammation was determined using immunohistochemistry. RESULTS: IR reduced V(max) (8.5 ± 2.2 vs 10.2 ± 1.8 µmol O(2)/min/g dry weight; P = .034), and increased dihydroethidium staining (134.8%; P = .039). IR decreased GPx expression (-47.9%; P = .048) and increased the proapoptotic marker Bax (255.5%; P = .020). Local PoC and rPoC further increased these deleterious effects. PoC decreased V(max) to 4.4 ± 1.4 µmol O(2)/min/g dry weight (sham vs PoC, -56.9% [P < .001]; IR vs PoC, -48.2% [P < .001]). rPoC similarly reduced V(max) to 5.1 ± 1.9 µmol O(2)/min/g dry weight (sham vs PoC, -50.0% [P < .001]; IR vs PoC, -40.0% [P = .001]). Dihydroethidium staining was further increased by PoC (207.2%; P = .002) and rPoC (305.4%; P < .001) compared with sham and was associated with macrophage infiltration. Local PoC increased SOD1, SOD2, and the antiapoptotic Bcl-2, and rPoC increased Bax (391.6%; P < .001) and the Bax/BclII ratio (621.7%; P < .001). CONCLUSIONS: Local and remote ischemic postconditioning further increased injury by enhancing mitochondrial dysfunction, oxidative stress production, and inflammation. Caution should be applied when considering ischemic postconditioning in vascular surgery.