Cardiovascular Effects of Shock and Trauma in Experimental Models. A Review

Dynamics of Local Temperature in the Fingertips After the Cuff Occlusion Test: Infrared Diagnosis of Adaptation Reserves to Hypoxia and Assessment of Survivability of Victims at Massive Blood Loss

BACKGROUND

Since changes in the tone and size of the lumen of peripheral blood vessels with massive blood loss are part of the mechanism of adaptation to hypoxia, which automatically changes the flow of warm blood to the fingertips, it was assumed that infrared thermography of the fingertips can reveal the dynamics of heat release in them, reflecting the reactivity of peripheral blood vessels and adaptation to hypoxia. It was assumed that the cuff occlusion test (COT) would assess the available reserves of adaptation to hypoxia and improve the accuracy of resistance to hypoxia and the prognosis of survival in massive blood loss.

METHODS

The temperature change in the fingertips before and after the application of COT in the corresponding hand was studied in healthy adult volunteers, donors after donating 400 mL of blood and in victims with blood loss of less than or more than 35%.

RESULTS

During COT, the temperature in the fingers of the ischemic hand decreased in all the subjects. After COT the temperature in the fingers rose above the baseline level in healthy volunteers and in donors who donated 400 mL of blood, but did not increase in most patients with massive blood loss, of which some patients died despite the treatment.

CONCLUSIONS

We report the dynamics of local temperature in the finger pads after the COT in healthy adult volunteers, in donors after they donated 400 mL of venous blood each, and in victims with massive blood loss less than or greater than 35%. It is shown that the detection of local hyperthermia in the finger pads after occlusion is a sign of good adaptation to hypoxia and the probability of survivability of the victim with massive blood loss.

Autophagy Is Involved in Stellate Ganglion Block Reversing Posthemorrhagic Shock Mesenteric Lymph-Mediated Vascular Hyporeactivity

Objective: The aim of this study was to clarify the role of autophagy in stellate ganglion block (SGB) reversing posthemorrhagic shock mesenteric lymph (PHSML)-mediated vascular hyporeactivity.

Methods: Hemorrhagic shock model in conscious rats was employed to observe the effects of SGB (0.2 ml of 0.25% ropivacaine hydrochloride hydrate) and autophagy inhibitor 3-methyladenine (3-MA; 30 mg/kg) on the vascular reactivity of second-order rat mesenteric arteries in vitro, while the effects of PHSML (1 ml/kg) and autophagy agonist rapamycin (Rapa, 10 mg/kg) on the beneficial effect of SGB were investigated. The cellular viability, contractility, and autophagy-related protein expressions in vascular smooth muscle cells (VSMCs) were detected following treatments of PHSML, PHSML obtained from the rats that underwent hemorrhagic shock plus SGB (PHSML-SGB), and PHSML plus 3-MA (5 mM), respectively.

Results: Hemorrhagic shock significantly decreased the vascular reactivity to gradient norepinephrine (NE), which is reversed by the SGB treatment and 3-MA administration. On the contrary, PHSML intravenous infusion and Rapa administration inhibited the vascular contractile responses in rats that underwent hemorrhagic shock plus SGB treatment. PHSML treatment significantly inhibited the cellular viability and contractility in VSMCs, increased the expressions of LC3-II and Beclin 1, and decreased the expression of p62, along with opposite appearances in these indices following PHSML-SGB treatment. In addition, 3-MA counteracted the adverse roles of PHSML in these indices in VSMCs.

Conclusion: SGB inhibits PHSML-mediated vascular hyporeactivity by reducing the excessive autophagy in VSMCs.

Exploring Vascular Function Biomarkers: Implications for Rehabilitation

The endothelium plays an important role in maintaining vascular homeostasis and regulating blood vessel function. Endothelial function is considered an independent predictor for risk of future cardiovascular events in cardiovascular and non-cardiovascular patients, as well as a predictor for postoperative complications in cardiovascular surgery patients. Brachial artery flow-mediated dilation by high-resolution ultrasound is widely used to evaluate endothelium-dependent vasodilation, which is mainly mediated by nitric oxide release. Physical exercise exerts beneficial effects on endothelial function and can be used in both primary and secondary prevention of cardiac and peripheral artery diseases, even in the postoperative period of cardiovascular surgery.

Anterior Spinal Artery Syndrome Following Coronary Artery Bypass Grafting: a Case Report

We present a patient with unstable angina candidate for coronary artery bypass grafting. Saphenous vein graft was used in obtuse marginal and left internal mammary artery to left anterior descending artery properly. After surgery, the patient experienced flaccid paralysis of lower limb and impaired sensation of touch and warmth of knee and below. A computed tomography angiogram of lower limbs and thoracolumbar magnetic resonance imaging showed no abnormality. Based on the symptom, clinical diagnosis of anterior spinal artery syndrome was considered. The artery of Adamkiewicz is an important supplier to the anterior spinal artery. Internal thoracic mammary artery, used in coronary artery bypass grafting, is suspected as a collateral supplier of the artery of Adamkiewicz and has been accused for cause of spinal infarction.