A Traumatic Shock

By Dr. Vishaal Bhat on Monday, 19 November, 2007 with 0 comments

It is well known from a long-time praxis that isolated injuries of the facial skeleton, the teeth and soft tissues do not usually evoke a traumatic shock. This complication may appear, however, with combined injuries or poly-traumas.

The definition

The term shock designates a severe, general hemodynamic and metabolic disorder caused by insufficient blood supplies. Three basic parts of the blood circulation are affected during the shock:

  • loss of circulation

  • defects in permeability of vessels

  • heart output decrease

The result is a decrease of the nutritional blood supply to the vital tissues and hypoxia. Insufficient removal of metabolites from tissues causes an acidosis. Irreversible damages to important organs originate from a developing shock: “shock kidneys”, “shock lungs”.

Causes of a shock

Hypovolaemic shock:

  • hemorrhagic: blood losses, low damage of tissues

  • traumatic: large damage of tissues

  • burns related: losses of plasma

  • dehydration related: losses of water (diarrhea, vomiting)

Other types of shocks: cardiogenic, septic, anaphylactic.

Stages of a shock

The first stage - compensation

Independently of a shock causes, the volume of circulating blood changes (macrocirculation), as well as specific shock-related changes of circulation inside blood vessels (microcirculation). At the first stage, the organism protects itself by a sympathetic-adrenergic reaction, releasing of catecholamines and excitation of adrenal cortex, in order to maintain homeostasis. Excitation of alpha-receptors of sympathetic nerves leads to closure of pre- and post-capillary sphincters which causes decrease of blood supply to organs depending on the degree of their alpha-adrenergic innervation (splanchnic organs, kidneys, liver, skin). On the other hand, coronary and brain circulations remain unaffected - centralization of circulation. The vital organs continue to be supplied with nutrients.

The second stage - decentralization of circulation

After the first stage, a shock deepens and without a compensation, serious metabolic malfunctions occur, tissue hypoxia and acidosis (lactate, ketoacids) increase, damages of cell membranes are caused by failure of the sodium-potassium pump (retention of Na+ and losses of K+). Decentralization of circulation appears, blood flows into the interstices after an initial peripheral spasm. Microcirculation specific changes also happen, characteristic by hemo-concentration, platelets sticking together, increasing blood viscosity, formation of thrombi, defects of DIC (disseminated intravascular coagulation) and appearance of consumptive coagulopathies.

A decompensated shock originates at this stage!

Therapy of a shock

A sudden loss of blood requires an adequate replacement. During the first stage, the blood volume is compensated for by replacement solutions, expanders, full blood, infusions, sugars, or salts. It is imperative to prevent any further blood losses (stop bleeding). A sufficient breathing and/or artificial ventilation of lungs (including also intubation) has to be ensured.

Therapy by medication: pain relief, vegetative blockers, corticoids, cardiotonics, prophylaxis of kidneys failure, occasionally a dialysis. A specific therapy is applied for particular types of shocks.

Category: Oro-Maxillo Facial Surgery Notes



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