TOC | Cardiology   
SHOCK

SX: Diminished perfusion (BP systolic usually <90) in

• CNS: restlessness, confusion, stupor & coma
• CV : ischemic chest pain, arrhythmia, cardiac failure
• Pulm: dyspnea & tachypnea, cyanosis
• Renal: decreased urine output <25 ml/hr
• Skin: usually cool, clammy, mottled, pale (except during early sepsis)

A. Cardiogenic shock:      Review: Annals of Internal Medicine, 6 July 1999. 131:47-59.
1. Heart Failure (esp. LV) - acute MI is the most common cause.
a. Reduced Inotropy

• Coronary Artery Disease: acute myocardial infarction or ischemia
• CARDIOMYOPATHY (see record)
• Myocarditis
• Misc: Drugs, Acidosis, etc

b. Pressure Overload

• Aortic Stenosis
• Hypertension
• IHSS/Asymmetric Septal Hypertrophy
• Coarctation of the Aorta

c. Volume Overload

• Aortic or Mitral Regurgitation, Left to Right Shunts

d. Reduced Diastolic Relaxation
      (1) Poor Compliance

• Ischemic Heart Disease
• Restrictive Cardiomyopathy
• Hypertrophied Muscle

      (2) Constrictive Disorder

• Pericardial Tamponade
• Constrictive Pericarditis
• Restrictive Cardiomyopathy

e. Obstruction of Left Atrial Emptying
     (1) Mitral Stenosis
     (2) Left Atrial Myxoma or Thrombus

2. Arrhythmias

3. Constrictive lesions: cardiac tamponate, pericarditis, etc.

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B. Hypovolemic shock:

1. Bleeding intravascular depletion
2. Dehydration poor intake, N&V, diarrhea, diabetic ketoacidosis, diabetes insippidus,adrenocortical insufficiency, peritonitis, pancreatitis, burns, ascites, villous adenoma, pheochromocytoma, diuretics.

C. Distributive shock:

1. Septic shock, or endotoxemia
2. Neurogenic factors
3. Anaphylaxis
4. Metabolic factors: acute respiratory failure, acute renal failure, hepatic failure,severe acidosis or alkalosis, drug overdose.
5. Endocrinologic disorders: adrenal insufficiency, hypothyroidism, diabetic ketoacidosis, hyperosmolar nonketotic hyperglycemic coma, hypoglycemia, diabetes insipidus, etc.
6. Microcirculatory impairment: polycythemia vera, hyperviscosity syndrome, sickle cell anemia, fat emboli

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2000