Biology: Bleeding and Shock, Cardiac Cycle

Bleeding and Shock

• Bleeding can be external and obvious or internal and hidden, and can cause 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 autonomic nervous system monitors the body's needs and adjusts the blood flow as required, and when this fails, the body experiences hypoperfusion or shock.

Cardiac Cycle

• 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.
• Preload is the amount of blood returned to the heart to be pumped out, and afterload is the pressure in the aorta or peripheral vascular resistance against which the left ventricle must pump blood.
• Stroke volume is the amount of blood ejected per contraction, and is dependent on heart rate, stroke volume, hemoglobin levels, and arterial oxygen saturation.

Hemorrhage and Bleeding

• Hemorrhage is the discharge of blood from blood vessels, and can range from minor capillary bleeding to severely spurting artery bleeding.
• External bleeding can be controlled using direct pressure, pressure dressings, splints, hemostatic dressings, tourniquets, and pressure bandages.
• Internal hemorrhage can occur in any part of the body, and may appear with non-traumatic internal bleeding such as GI bleeding, ruptured ectopic pregnancies, or ruptured aneurysms.

Signs and Symptoms of Bleeding

• Signs of bleeding may include weakness, shock, dizziness, faintness, pain, swelling, bruising, distension, and hematoma.
• Patients may exhibit altered level of consciousness, tachycardia, weakness, fainting, dizziness, thirst, nausea, and vomiting.

Assessing and Managing Bleeding

• Assessing patients for bleeding involves searching for signs of shock, controlling lifethreatening bleeding, and performing a rapid full body scan to determine the patient's level of consciousness.
• Managing bleeding involves supporting the heart, brain, and spinal cord, and may require expedited transport to the hospital, depending on the severity of the bleeding.
• Consider factors such as need for stitches, tetanus shot, and patient reliability when making transport decisions.

Trauma and Bleeding

• Trauma patients may experience hypovolemic shock, which can be fatal if not corrected.
• The trauma "triad of death" consists of hypothermia, coagulopathy, and acidosis, which can increase mortality in trauma patients.
• Identify and intervene in these conditions by keeping patients warm, managing bleeding, and providing oxygen and other necessary treatments.

Bleeding and Shock

• Bleeding can be internal and hidden, causing 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
• The autonomic nervous system monitors the body's needs and adjusts the blood flow as required, and when this fails, the body experiences hypoperfusion or shock

Cardiac Cycle

• 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
• Preload is the amount of blood returned to the heart to be pumped out
• Afterload is the pressure in the aorta or peripheral vascular resistance against which the left ventricle must pump blood
• Stroke volume is dependent on heart rate, stroke volume, hemoglobin levels, and arterial oxygen saturation

Hemorrhage and Bleeding

• Hemorrhage is the discharge of blood from blood vessels, ranging from minor capillary bleeding to severely spurting artery bleeding
• External bleeding can be controlled using direct pressure, pressure dressings, splints, hemostatic dressings, tourniquets, and pressure bandages
• Internal hemorrhage can occur in any part of the body, and may appear with non-traumatic internal bleeding such as GI bleeding, ruptured ectopic pregnancies, or ruptured aneurysms

Signs and Symptoms of Bleeding

• Signs of bleeding include weakness, shock, dizziness, faintness, pain, swelling, bruising, distension, and hematoma
• Patients may exhibit altered level of consciousness, tachycardia, weakness, fainting, dizziness, thirst, nausea, and vomiting

Assessing and Managing Bleeding

• Assessing patients for bleeding involves searching for signs of shock, controlling lifethreatening bleeding, and performing a rapid full body scan to determine the patient's level of consciousness
• Managing bleeding involves supporting the heart, brain, and spinal cord, and may require expedited transport to the hospital, depending on the severity of the bleeding
• Factors to consider when making transport decisions include need for stitches, tetanus shot, and patient reliability

Trauma and Bleeding

• Trauma patients may experience hypovolemic shock, which can be fatal if not corrected
• The trauma "triad of death" consists of hypothermia, coagulopathy, and acidosis, which can increase mortality in trauma patients
• Identify and intervene in these conditions by keeping patients warm, managing bleeding, and providing oxygen and other necessary treatments