Blood Volume and Management Quiz

Introduction

• Paramedics are shifting their focus away from airway management to bleeding
• Bleeding is now recognized as a critical, time-sensitive condition that can lead to shock
• Shock is a state of collapse and failure of the cardiovascular system, leading to inadequate tissue perfusion
• Untreated shock can damage vital organs and cause death

Anatomy and Physiology of the Cardiovascular System

• The cardiovascular system's crucial function is maintaining blood flow carrying oxygen to the tissues and waste products away
• In the lungs, blood releases carbon dioxide and picks up oxygen
• In the peripheral tissues, blood unloads oxygen and picks up waste products
• Disruption or slowing of blood flow disrupts oxygen delivery
• Emergency metabolic system (which does not require oxygen) produces toxic metabolic waste

Anatomy and Physiology of the Heart

• The heart is a muscular cone-shaped organ located behind the sternum
• It's roughly the size of a closed fist and weighs between 280-350g in men and 225-280g in women
• The heart has four chambers: two atria and two ventricles
• The atria receive deoxygenated blood from the body, and the ventricles pump blood out to the body and lungs
• Atrioventricular and semilunar valves regulate blood flow within the heart

Blood Flow Within the Heart

• Pathways of blood flow through the heart
• Superior and inferior vena cava bring deoxygenated blood to the right atrium
• Blood travels through the tricuspid valve to the right ventricle
• The right ventricle pumps blood through the pulmonic valve to the lungs
• The lungs oxygenate the blood, and the freshly oxygenated blood returns to the left atrium via the pulmonary veins
• Blood passes through the mitral valve into the left ventricle
• The left ventricle pumps oxygenated blood through the aortic valve into the aorta to the rest of the body

The Cardiac Cycle

• The repeating pumping process of the heart
• Begins with the contraction of cardiac muscle and ends before the next contraction
• Factors like stroke volume and heart rate influence cardiac output, impacting oxygen delivery to tissues
• Increased venous return stretches the ventricles, leading to increased cardiac contractility (Starling's Law of the Heart)
• Ejection fraction, the percentage of blood pumped per contraction, maintains normal cardiac function

Blood and its Components

• Blood is composed of plasma and formed elements (cells)
• Plasma is a watery fluid containing 92% water and dissolved substances (8% dissolved substances)
• Red blood cells (erythrocytes) are disc-shaped, most numerous, contain hemoglobin to carry oxygen, and are responsible for the reddish color
• White blood cells (leukocytes) are crucial for fighting infections
• Platelets are essential for clot formation

Blood Circulation and Perfusion

• Blood vessels, including arteries, veins, arterioles, and capillaries, form the circulatory system
• Perfusion is the circulation of blood in sufficient amounts to meet the cells' needs
• Blood must travel at a sufficient but not overwhelming speed to allow cells to exchange oxygen and nutrients.

Autonomic Nervous System

• Continuously monitors the body's needs
• Can redirect blood flow during emergencies, prioritizing critical organs (heart, brain, lungs, kidneys)

Perfusion Needs

• Continuous blood flow is crucial, especially for the heart and spinal cord.
• Kidneys and skeletal muscles require perfusion for optimal performance.
• The time organs can handle inadequate perfusion depends on factors like organ location and temperature.

Pathophysiology of Hemorrhage

• Hemorrhage refers to bleeding, ranging from minor wounds to severe internal bleeding.
• External bleeding typically occurs when skin is broken. Capillary bleeding seeps; venous flows, and arterial spurts.
• Internal bleeding, often less visible but equally dangerous, can originate from various causes.

External Hemorrhage

• External bleeding occurs when skin is broken.
• Severity and type of wound impact bleeding.
• Artery bleeding typically spurts; venous flows, and capillary oozes.
• Other injuries can worsen bleeding.

Internal Hemorrhage

• Internal bleeding is less visible bleeding.
• Trauma is a common cause.
• Locations like the digestive tract, ruptured ectopic pregnancies, and abdominal aneurysms are locations to consider
• Treatment involves prompt action, focusing on shock treatment and quick transport to hospitals.

Controlled Versus Uncontrolled Hemorrhage

• External bleeding is typically controlled with direct pressure and elevation.
• Arterial bleeding requires more time to clot. Tourniquets are used for controlled bleeding when direct pressure doesn't work
• Internal bleeding usually needs rapid transportation for treatment

The Significance of Bleeding

• Determining the amount of blood lost is difficult; location influences visual perception.
• Adults lose 70-65mL/kg of blood according to gender and weigh.
• Blood loss over 20% body volume is serious and requires prompt medical attention
• Rate of loss impacts the severity of symptoms.

Physiologic Response to Hemorrhage

• There are three major types of bleeding to consider: arterial, venous, and capillary
• Different reactions occur based on the bleeding type.
• Blood flow is controlled by the hemostatic system, which can fail in certain situations.
• Internal clotting mechanisms or exposure to air will stop bleeding.

Shock-Related Events

• Capillary and microcirculatory levels
• Declining perfusion decreases oxygen delivery to cells
• Cellular metabolism shifts from aerobic to anaerobic.
• Acidity accumulates and damages tissue, leading to the final phase of shock

Systemic Inflammatory Response Syndrome (SIRS)

• A condition triggered by severe clinical insults.
• Manifested by certain temperature, heart rate, respiratory rate and white blood cell counts.
• Cytokines are central mediators in the development of SIRS.
• Specific organs and systems affected (cardiovascular, respiratory, central nervous, renal, liver and gastrointestinal) can all be impacted and have abnormalities, like low perfusion pressure, tachycardia and hypotension, tachypnea, decreased/absent reflexes, impaired/absent sensations under the injury site.
• Uncontrolled SIRS can progress to multiple organ dysfunction syndrome (MODS), potentially resulting in death

Phases of Shock

• Shock has three stages: compensated, decompensated, and irreversible.
• Compensated shock: body can still compensate for blood loss, blood pressure maintained
• Decompensated shock: blood pressure falls, body's compensatory mechanisms fail
• Irreversible shock: significant organ damage, and medical intervention may not be sufficient to reverse the condition

The Clinical Picture of Hypovolemic Shock

• Early signs include restlessness, anxiety, and a scared look.
• Late signs include a decline in tissue perfusion.
• Dehydrated patients often display pale, cool, clammy skin.

Treatment of a Patient With Suspected Shock

• Airway and ventilation support is paramount
• High-flow supplemental oxygen is used.
• Any external bleeding must be quickly controlled
• Large-bore IV lines and crystalloid fluid challenge
• Rapid transport and appropriate medical centers can be crucial

IV Therapy

• IV fluids are inserted for immediate fluid replacement
• Various fluid types and rates of infusion are based on the suspected cause/issue of shock.
• Volume expanders and plasma substitutes to replenish lost fluids.

Management of Specific Types of Shock

• Hypovolemic shock management priorities are controlling bleeding, establishing an open airway and keeping the patient warm.
• Cardiogenic shock treatment should be time sensitive.
• Neurogenic shock requires immobilization and warm fluids.
• Anaphylactic shock management includes removing the cause and administering epinephrine, and bronchodilators.
• Use of medical directives and protocols are vital

Transportation of Patients With Suspected Shock

• Assessing the need for prompt transport for suspected shock patients, prioritizing those with severe internal bleeding, or those in cardiogenic shock, is crucial

Prevention Strategies

• Preventing shock incidents by following safety measures, and assessing the severity of incidents, like during a trauma event, is crucial

Summary

• Short summary of the slides content
• Covering anatomy, hemorrhage, shock, shock assessment and management

IV Theory (Fluids and Electrolytes)

• Major electrolytes in the body include sodium (Na+), potassium (K+), calcium (Ca++), chloride (Cl-), magnesium (Mg++), and phosphate (HPO4--).
• Each has specific functions and normal ranges.
• Variations from these ranges can affect bodily functions, leading to possible shock

Acid Base Balance

• A crucial process in maintaining homeostasis: normal blood pH is 7.35–7.45
• Buffer systems, respiratory mechanisms, and the kidneys regulate pH levels
• Normal saline solution is used for maintaining the body's pH balance when needed.

IV notes

• Various procedures/practices for performing IV therapy, including procedures to prevent problems
• Procedures to take in case of complications during IV insertion

Test your knowledge on blood volume in adults and the critical management of blood loss. This quiz covers fundamental concepts related to blood volume, hemorrhage control, and the application of medical interventions in emergencies. Perfect for medical students and healthcare professionals.