Why do you cross-clamp the aorta in trauma?
First, for patients with hemorrhagic shock, aortic cross-clamping redistributes the patient’s limited blood volume to the myocardium and brain. Second, patients sustaining intra-abdominal injury benefit from aortic cross-clamping owing to a reduction in subdiaphragmatic blood loss.
What is the major concern of clamping the aorta?
The clamp-induced increase in cardiac afterload raises mean arterial pressure, causing shifts in blood volume and increasing myocardial oxygen demand, which can lead to left ventricular decompensation and failure.
Why do surgeons cross-clamp the aorta?
During open aortic surgery, interrupting the blood flow through the aorta by applying a cross-clamp is often a key step to allow for surgical repair. As a consequence, ischemia is induced in parts of the body distal to the clamp site.
What is aortic cross-clamp time?
In the majority of patients, 30–90 min of cross-clamp time was required. Less than 2% of patients required cross-clamp times greater than 120 min and these patients were excluded for the reasons noted above.
Why do doctors crack the chest?
Open-heart surgery requires opening the chest wall to make the heart easier for the surgeon to reach. To access the heart, surgeons cut through the sternum (breastbone) and spread the ribs. Sometimes people call this cracking the chest.
When is thoracotomy indicated?
Thoracotomy is indicated when total chest tube output exceeds 1500 mL within 24 hours, regardless of injury mechanism. THE INDICATIONS for thoracotomy after traumatic injury typically include shock, arrest at presentation, diagnosis of specific injuries (such as blunt aortic injury), or ongoing thoracic hemorrhage.
What happens when the aorta is clamped?
An increase in filling pressures and left ventricular end-diastolic volume during cross-clamping of the aorta may result from blood volume redistribution from the venous vasculature in the lower part of the body to the upper part of the body, or it may represent an increase in afterload with subsequent increase in the …
What is cross clamp fibrillation?
Cross-clamp fibrillation is a well established method of performing coronary grafting, but its clinical effect on the myocardium is unknown. We sought to measure these effects clinically using the Khuri Intramyocardial pH monitor.
What is cross-clamp fibrillation?
What is clamp time?
The time at which the flow of blood to a particular organ has been clamped off during a procurement.
Is the heart stopped during open heart surgery?
Your heart will not be stopped during surgery. You will not need a heart-lung machine. Your heart and lungs will continue to perform during your surgery. Surgeons use a tissue stabilization system to immobilize the area of the heart where they need to work.
What is the pathophysiology of aortic cross clamping?
The pathophysiology of aortic cross-clamping During open aortic surgery, interrupting the blood flow through the aorta by applying a cross-clamp is often a key step to allow for surgical repair. As a consequence, ischemia is induced in parts of the body distal to the clamp site.
What is the clinical significance of cross-clamping of the thoracic aorta?
A clinically relevant message from these findings [34] is that during cross-clamping of the thoracic aorta, which subjects vitally important organs (liver, kidneys, and spinal cord) to severe ischemia, proximal and distal aortic pressures should be maintained as great as the heart can withstand.
What is the effect of cross clamping on thoracic aorta in dogs?
Cross-clamping of the thoracic aorta is associated with almost a twofold increase in blood flow through the upper part of the body, [19-21] more than a threefold increase in blood flow through the muscle proximal to the clamp, [33] and a dramatic decrease in canine hind-leg volume as determined by mercury strain-gauge plethysmography. [38]
What are the mediators associated with aortic cross-clamping?
Aortic cross-clamping is associated with the formation and release of many mediators. These mediators represent a double-edged sword: they may reduce or aggravate the harmful effects of aortic cross-clamping and unclamping.