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Shock and Hypertension

Cardiovascular shock
Inadequate supply of O₂ to the tissues
Results in loss of tissue function and loss of corrective reflexes
Note: especially the heart & nervous system

PROBLEMS PRESENTED BY SHOCK
•     decreased cardiac output
•     decreased VR !!!
•     loss of sympathetic reflexes
•     tissue dehydration (    BP)
•     renal failure

Shock
•     Anaphylactic
•     Cardiogenic
•     Emotional stress
•     Hemorrhagic
•     Also burns

SYMPTOMS:
•     Cold, clammy skin
•     Rapid shallow pulse
•     Dilated pupils
•     Loss of pupillary reflex
•     Edema

Treatments
•     Elevate feet
•     Keep warm
•     Plasma expanders
•     Epinephrine

Reversible – NonReversible Border:
Oxygen deficit of > 120 ml/Kg body weight

HYPERTENSION
see Box on page 450

•     Increased TPR
•     “Essential” or idiopathic
•     Atherosclerosis
        •     Decreased arterial compliance
•     Arteriosclerosis
        •     plaque deposit in major vessel

POSITIVE FEEDBACK
Increased TPR --> increased cardiac work
---> Increased cardiac muscle mass (hypertrophy)
---> Increased bv muscle mass & TPR
Increased cardiac O₂ demand !!!
Also
Decreased BV compliance over time
Made worse by ‘re-setting’ of the baroreceptors as the BVs lose their compliance

Potential problems
•     Myocardial disease
•     Heart attack and infarct
•     ---> increased work for remaining healthy tissue
•     Decreased VR ----> edema
•     Liver
•     Lungs
•     Kidney
•     Edema
      Swelling of the tissues due to fluid accumulation from the capillaries
      Increased BP in tissues
      Decreased VR
      Increased TPR

Possible Treatments
•     Vasodilators
•     “False NTs” - methyl DOPA
•     Diuretics
• Blockers
•     Sedatives