Lidocaine is a medication that will be given through a vein (intravenously) during the study. It is commonly used as a local anesthetic to numb areas of the body, but in this trial it is being tested to see if it can help reduce inflammation in the body that happens during heart surgery when a heart-lung machine is used. The researchers want to find out if this medication can lower certain inflammatory markers in the blood after surgery.

Placebo is an inactive substance that looks like the real medication but contains no active medicine. Some patients will receive this instead of lidocaine so that researchers can compare the results and determine if lidocaine actually has an effect on reducing inflammation during heart surgery.

Systemic Inflammatory Response Syndrome – Systemic inflammatory response syndrome is a widespread inflammatory reaction of the body that can occur after major surgical procedures, particularly those involving cardiopulmonary bypass during heart surgery. The condition develops when the immune system releases inflammatory substances throughout the bloodstream in response to surgical trauma or other triggers. This response involves the release of various inflammatory markers, including interleukin-6, C-reactive protein, and tumor necrosis factor alpha. The syndrome can affect multiple organ systems as inflammation spreads through the body. Patients may experience increased body temperature, elevated heart rate, and changes in white blood cell counts. The condition can lead to various complications affecting the kidneys, lungs, heart, and other organs if the inflammatory response becomes excessive.

Acute Kidney Injury – Acute kidney injury is a sudden decline in kidney function that can occur as a complication following cardiac surgery. The condition develops when the kidneys lose their ability to filter waste products from the blood effectively. This dysfunction may result from reduced blood flow to the kidneys, inflammatory processes, or direct injury during surgical procedures. Patients experience a buildup of waste products in the blood and may have changes in urine output. The severity can range from mild dysfunction to complete loss of kidney filtering ability. The condition typically develops within hours to days after the triggering event.

Sepsis – Sepsis is a serious condition that occurs when the body’s response to an infection causes widespread inflammation throughout the body. The condition can develop after surgery if bacteria or other infectious agents enter the bloodstream or tissues. The immune system releases chemicals to fight the infection, but these substances can trigger inflammatory changes that affect multiple organ systems. Patients may experience fever, rapid heart rate, rapid breathing, and confusion. The condition represents a dysregulated immune response where the body’s defense mechanisms cause harm to its own tissues. Sepsis can progress rapidly and affect blood pressure, organ function, and tissue perfusion.

Multiple Organ Dysfunction Syndrome – Multiple organ dysfunction syndrome is a condition where two or more organ systems fail to function properly simultaneously. This syndrome can develop as a consequence of severe systemic inflammation, inadequate blood flow, or other complications following major surgery. The condition typically progresses over time as one failing organ system places additional stress on others. Affected organs may include the lungs, kidneys, liver, heart, and brain. Each organ’s dysfunction contributes to the overall deterioration of the patient’s condition. The syndrome represents a cascade of physiological failures where the body’s systems can no longer maintain normal function.

Vasoplegia – Vasoplegia is a condition characterized by severe dilation of blood vessels leading to abnormally low blood pressure despite adequate fluid volume in the circulatory system. The condition commonly occurs after cardiac surgery involving cardiopulmonary bypass due to inflammatory responses. Blood vessels lose their normal tone and ability to constrict properly, causing blood pressure to drop. The heart may pump adequately, but the dilated vessels cannot maintain sufficient pressure for proper blood flow to organs. Patients require medications to help constrict blood vessels and restore normal blood pressure. The condition results from complex inflammatory and metabolic changes affecting the vessel walls.

Ventricular Fibrillation – Ventricular fibrillation is a severe abnormal heart rhythm where the lower chambers of the heart quiver rapidly and chaotically instead of beating effectively. During this arrhythmia, the heart cannot pump blood to the body because the muscle fibers contract in an uncoordinated manner. The condition can occur spontaneously during cardiac surgery, particularly when blood flow is restored to the heart after aortic clamping. The electrical signals in the heart become disorganized, causing the ventricles to flutter at very high rates. Without coordinated contractions, the heart cannot maintain circulation. The rhythm must be corrected quickly to restore normal heart function and blood flow.