Head injury can cause several different pathologic event including intracranial hematomas, cerebral edema and systemic effects.
The goals of early management of the patient with head trauma are two fold.
First, Prevention of secondary injury must be attempted aggresively.
Second, A rapid decision needs to be made as to wether emergency surgical exploration is required.
Brain damage a result of head injury can be devide into primary and secondary injury. Primary injury is the injury occuring during the trauma event itself, cannot be minimized.
Secondary injury is the injury occuring after the traumatic events, as a result of hypoxia, hypercapnia, and ischaemia induced by hypotension, vasospasm or Increase Intracranial pressure (ICP).
The most important contribution to secondary injury are hypoxaemia and hypovolemic with hypotension.
Mechanical Injury, hemorrhage, edema and Ischaemia are the most important causes of brain damage in patients with head injury.
Particularly the edema and Ischemia that are concern to anesthesiologist.
The importance of secondary injury to outcome is most clearly demonstrated by those patients who, at some point after injury are concious and talk, only to subsequently deteriorate and die. The children have more commonly diffuse cerebral edema.
Up to 50% of head trauma will have significant often life threatening associated injuries. Associated injuries usually involve the neck, chest and abdominal organ.
Although massive head injury and neck injury may result in shock, intrathoracic and abdominal bleeding should always
be considered in differential diagnosis of hypotension.
The anesthesiologist should be fully aware of these associated injuries because their presence may have a significant impact on anesthetic management. Single episode of hypotension occuring between injury and resuscitation will increase in mortality of almost 50%.
65% of spontaniously breathing head injured patients may be hypoxaemia even though they may not appear to be in respiratory distress.
Providing a secure airway is crucial in the management of head trauma but stabilization for cervical is mandatory.
Fluid balance is important, a combination of crystaloid (to replace normal fluid requirement), colloid and blood may be needed.
The target is normovolemia, Isoosmular, normoglygaemic. Dextrose containing solutions are avoided except in infants or where documented hypoglycaemia, because hypergly
lycaemia is thought worse tissue damage caused by Local cerebral Ischaemia.
Coagulation disturbances occur up to 24% of patient with severe, are indicative of poor outcome.
To be continued
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