Physiology Chapter: Bleeding and Cardiac Cycle

Study Notes

Bleeding can be external and obvious or internal and hidden, leading to conditions such as weakness, shock, and death.
Perfusion is the circulation of blood within an organ or tissue in adequate amounts to meet the cell's current needs for oxygen, nutrients, and waste removal.

The cardiac cycle is a repetitive pumping process that begins with the onset of cardiac muscle contraction and ends with the beginning of the next contraction.
The cardiac cycle is connected to bleeding and shock through its relationship to blood pressure.
Delivery of oxygen to the tissues is dependent on an adequate heart rate, stroke volume, hemoglobin levels, and arterial oxygen saturation.

Hemorrhage is the discharge of blood from blood vessels, ranging from minor capillary bleeding to severely spurting arteries.
External bleeding is often controlled by using direct pressure, pressure dressings, splints, hemostatic dressings, tourniquets, and pressure bandages.
Internal hemorrhage may appear in any portion of the body, occurring with non-traumatic internal hemorrhage such as GI bleeding, ruptured ectopic pregnancies, and ruptured aneurysms.

High-energy mechanisms of injury, such as falls, blast injuries, and MVCs, increase the index of suspicion for serious unseen injuries.
Penetrating injuries or significant blunt trauma can cause internal bleeding.

Signs of internal bleeding include dizziness, faintness, weakness, pain, swelling, bruising, distension, hematoma, and vomiting blood.
Altered level of consciousness, tachycardia, weakness, fainting, dizziness, and thirst are signs of hypoperfusion.

Hemorrhagic shock is the condition in which blood flow volume results in inadequate perfusion and even death.
Uncontrolled bleeding, whether internal or external, can eventually lead to hemorrhagic shock if not corrected.

Patients with significant bleeding or suspected internal bleeding should be transported to the hospital immediately.
On-scene management includes controlling external bleeding, providing oxygen, and covering the patient to prevent heat loss.
Patients with bleeding disorders or taking medications that interfere with clotting mechanisms require immediate transportation.
The trauma triad of death includes hypothermia, coagulopathy, and acidosis, which increase mortality in trauma patients.

Patient assessment should begin with scene size-up, ensuring the scene is safe and taking appropriate standard precautions.
The primary survey should be used to search for life-threatening bleeding, control it, and assess the patient's level of consciousness, airway, breathing, and circulation.
Secondary assessment should uncover any injuries or illnesses missed during the primary survey and gather information about the patient's chief complaint and MOI.
Vital signs should be recorded every 5 minutes, and the patient's respiratory, cardiovascular, neurologic, and musculoskeletal systems should be assessed.

Bleeding can be internal and hidden, leading to weakness, shock, and death
Internal bleeding can be caused by non-traumatic internal hemorrhage, such as GI bleeding, ruptured ectopic pregnancies, and ruptured aneurysms

The cardiac cycle is connected to bleeding and shock through its relationship to blood pressure
Delivery of oxygen to tissues is dependent on adequate heart rate, stroke volume, hemoglobin levels, and arterial oxygen saturation

Hemorrhage is the discharge of blood from blood vessels, ranging from minor capillary bleeding to severely spurting arteries
External bleeding can be controlled using direct pressure, pressure dressings, splints, hemostatic dressings, tourniquets, and pressure bandages

High-energy mechanisms of injury, such as falls, blast injuries, and MVCs, increase the suspicion for serious unseen injuries
Penetrating injuries or significant blunt trauma can cause internal bleeding

Signs of internal bleeding include dizziness, faintness, weakness, pain, swelling, bruising, distension, hematoma, and vomiting blood
Altered level of consciousness, tachycardia, weakness, fainting, dizziness, and thirst are signs of hypoperfusion

Hemorrhagic shock is a condition in which blood flow volume results in inadequate perfusion and even death
Uncontrolled bleeding, whether internal or external, can eventually lead to hemorrhagic shock if not corrected

Patients with significant bleeding or suspected internal bleeding should be transported to the hospital immediately
On-scene management includes controlling external bleeding, providing oxygen, and covering the patient to prevent heat loss
Patients with bleeding disorders or taking medications that interfere with clotting mechanisms require immediate transportation
The trauma triad of death includes hypothermia, coagulopathy, and acidosis, which increase mortality in trauma patients

Patient assessment should begin with scene size-up, ensuring the scene is safe and taking appropriate standard precautions
The primary survey should be used to search for life-threatening bleeding, control it, and assess the patient's level of consciousness, airway, breathing, and circulation
Secondary assessment should uncover any injuries or illnesses missed during the primary survey and gather information about the patient's chief complaint and MOI
Vital signs should be recorded every 5 minutes, and the patient's respiratory, cardiovascular, neurologic, and musculoskeletal systems should be assessed