All cardiovascular disorders, Study notes of Health sciences

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CARDIOVASCULAR DISORDERS

Expected learning outcomes

By the end of this lecture the student should

be able to:

❖ Describe the normal anatomy and

physiology of the cardiovascular system.

❖Explain the special cardiac procedures

❖Describe various cardiovascular disorders

❖Describe the nursing management for

cardiovascular disorders.

LEARNING OUTCOME

• Define Shock
• Recognize the stages of shock
• Classify shock into subcategories based on cause
• Understand septic shock as it relates to sepsis
• Identify pharmacological therapy based on type of

shock

• Identify goals of treatment based on type of shock

DEFINITION

• A state with reduction/inadequate systemic tissue

perfusion resulting in decreased delivery of oxygen

and reduced removal of waste products leading to

tissue injury.

• Inadequate tissue perfusion leads to inadequate

amount of oxygen delivery to the tissues which leads

to ischemia - then necrosis and eventually to organ

failure

STAGES OF SHOCK

1.Compensatory

2.Progressive

3.refractory

STAGES OF SHOCK: SUBCLINICAL STAGE The decrease in blood flow to the tissues causes a reduction in the delivery of oxygen and nutrients to the cells. Anaerobic metabolism takes over and produces lactic acid. Energy production is reduced

STAGES OF SHOCK: PROGRESSIVE STAGE/DECOMPENSATION The body’s compensatory mechanisms are not able to sustain the patient in a homeostatic state and the compensatory mechanisms begin to fail. Cardiac output and tissue perfusion are decreased, which leads to cellular dysfunction and eventual cell death. The first major system that usually fails is the renal system, followed by pulmonary, heart and then gastrointestinal tract

STAGES OF SHOCK: REFRACTORY STAGE ❑The patient does not respond to conventional therapy and death ensues/follows. ❑The patient continues to get worse as the tissue perfusion decreases, acidosis increases, and organs fail

HYPOVOLEMIC SHOCK

• Low fluid volume in the blood
• Decrease in intravascular volume of 15% or more
• Stroke volume (Stroke volume is the amount of blood ejected from the ventricle with each cardiac cycle), cardiac output (the amount of blood the heart pumps each minute), and blood pressure decreased CAUSES

1. Hemorrhage
2. Burns
3. severe dehydration

HYPOVOLEMIC SHOCK

4. Loss of large amount of body fluids: trauma, continuous NG suctioning, vomiting, diarrhea, diuretics, surgery, diabetes insipidus, liver disease, hyperglycemia , bleeding disorders, GI bleeding
5. Inadequate fluid replacement

HYPOVOLEMIC SHOCK SIGNS AND SYMPTOMS

• Cardiac : Heart rate increases as vasoconstriction increases, and Reduced BP
• Respiratory: Increased respiratory rate
• Renal: reduced urine output (less than 30ml/hr)
• Skin: pallor, cool
• Neurological : confusion, agitation
• Gastrointestinal: no bowel sound
• NB/ Remember: Low fluid volume

HYPOVOLEMIC SHOCK: MANAGEMENT

1. Locate cause and correct

➢Return to surgery for surgical cause

➢Direct pressure for trauma cause

➢Antiemetics antidiarrheals, for severe dehydration

from vomiting or diarrhea

2. Provide O

3. Obtain IV access (at least 2 large bore IVs

recommended)

CARDIOGENIC SHOCK

• Heart’s pumping ability is compromised to the point that it cannot maintain cardiac output and adequate tissue perfusion CAUSES:
• MI, cardiac tamponade, restrictive pericarditis, dysrhythmias,
• E.g. valve pathologies, cardiomyopathies, electrolyte imbalances, head injuries

CARDIOGENIC SHOCK: PATHOPHYSIOLOGY

• Blood volume is adequate however the heart cannot pump blood in the systemic circulation.
• Coronary causes: damaged cardiac muscle is nonfunctional- it cannot contract or contract well and therefore cannot move preload forward into the aorta or coronary ostia reducing coronary artery perfusion leading to more ischemia and a vicious cycle.
• Noncoronary cases: any disease process or pathology that reduces the pumping ability of the heart will reduce the amount of blood able to be ejected from the heart in systole, reduce stroke volume, and therefore CO.