Veterinary Clinical Medicine-I (General and Systemic)

MANAGEMENT OF SHOCK

• Management of shock depends on rapid determination of the underlying cause. The causes and treatment principles of the various shock categories are listed below.
• Hypovolemic shock can be treated by replacing blood volume, either with crystalloids, colloids, or blood products as indicated. More information on this will be presented in the next session.
• Cardiogenic shock can be treated by reducing vascular volume (Furosemide 2mg/kg in dog; 1mg/kg in cats; PRN), causing peripheral vasodilation if indicated (nitroglycerin) or improving inotropy (Dobutamine).
• Obstructive shock can only be treated by relieving the obstruction, whether that is by decompressing the GDV, tapping the pericardial effusion or the pneumothorax, or otherwise de-obstructing flow. Vascular loading with IV fluids can also be of benefit, especially if decreased regional blood flow is the cause of shock (as occurs with GDV).
• Distributive shock can be very difficult to diagnose and treat. If vasodilation and hypotension are present, treatment with vasopressors (such as dopamine, vasopressin or norepinephrine infusions) can be beneficial. These patients may also respond to fluid loading, which is the first line treatment for septic shock.
• Anemic or hypoxemic shock can be treated with relative ease. RBC transfusions or Oxyglobin can be given in cases of anemia shock (more on this later). Hypoxemic shock will usually respond to supplemental oxygen, although mechanical ventilation may be indicated in more severe cases.
• Neurogenic shock is difficult to treat. The only known treatment is to treat the underlying cause. This may include administration of mannitol 1 g/kg IV or hypertonic saline in case of head trauma or CNS disease to reduce intracranial pressure.
• Treatment of metabolic shock is also aimed at correcting the underlying cause. Give dextrose 0.5g/kg IV bolus for hypoglycemia, but otherwise treatment is symptomatic and supportive.
• In Practice scenario, unfortunately, the cause of shock is not always readily apparent. With the exception of cardiogenic shock, it is never wrong to try an IV bolus of crystalloids. The "shock dose" of crystalloids should be given in ¼ - 1/3 aliquots over a 10-15 minute period. If cardiogenic shock is suspected (heart murmur on auscultation +/- crackles), a test dose of furosemide can be administered. The test dose for dogs is 2 mg/kg IV or IM, and for cats is 1 mg/kg IV or IM. IV fluids should not be routinely administered in cardiogenic shock.