In study session VI you have learnt
- Head injury is defined as any trauma to the head other than superficial injuries to the face. Any trauma victim with altered consciousness must be considered to have a brain injury.
- The primary injury is due to irreversible mechanical injury, but secondary injury which leads to cerebral ischemia, results from raised intracranial pressure, hypotension, hypoxia, anemia, seizures, hypoglycemia and hyperthermia.
- The main aim of assessment and management of head-injured patients is to maintain adequate cerebral blood flow and to avoid cerebral ischemia and hypoxia.
- Autoregulation is a protective mechanism that maintains a constant cerebral blood flow in the presence of a changing cerebral perfusion.
- Use the ABCDE approach to identify and treat life-threatening injuries early. First secure the air way.
- The basic level of consciousness is rapidly noted in the primary survey, while a more complete neurologic examination is performed as part of the secondary survey to assess the presence of traumatic, brain, spine, or spinal cord injuries.
- The cervical and thoracolumbar regions are most commonly affected by trauma, the patient must be log rolled and the entire spine examined for deformities or injuries.
- Indicators of cord damage are hypotension with bradycardia acute urinary retention, diaphragmatic respiration, priapism, lax anal sphincter and flaccid paralysis of the limbs.
- Until spinal injuries can be excluded or "cleared" the spine must be immobilized. Two methods are in common use, rigid collars and manual in-line stabilization.
- Clinical clearance of cervical injury includes no evidence of posterior cervical tenderness "no history of intoxication", "an alert patient", "no focal neurological deficit" and "no painful distracting injuries".
- Patients may require airway instrumentation as an emergency for airway obstruction, respiratory failure or as part of the management of a severe head injury or later in their management as part of anesthesia for surgical management of other injuries.
- Respiratory failure is common and pulmonary complications are the leading cause of death. The diaphragm (C3-C5) and intercostals (T1-T11) are the main inspiratory muscles.
- Cardiovascular instability is particularly seen with high cervical cord injuries.
- Autonomic dysreflexia symptoms may start weeks to years following the spinal injury and include paroxysmal hypertension, headaches and bradycardia.
- Common injuries requiring immediate surgical intervention including epidural hematoma, subdural hematoma, and some penetrating brain injuries and depressed skull fractures.
- Elevation of depressed skull fracture to alleviate elevated intracranial pressure and reduce brain ischemia might be done at the periphery until the patient has been transported to better hospital.
- The anesthetic assessment and management for head and spinal cord injury is a continuation of the general assessment and care, and the anesthetic considerations for emergency and trauma patient should be observed.
- All patients should be regarded as having a full stomach and should have cricoid pressure applied during ventilation and tracheal intubation.
- Administration of thiopental, 2-4 mg/kg, or propofol, 1.5-3.0 mg/kg, and rapid-onset relaxants. Suxamethonium should be avoided 48 hours following head and spinal cord injury or patient developed paraplegia.
- Blind nasal intubation is contraindicated in the presence of a basilar skull fracture.
- Glucose-containing or hypotonic solutions should not be used.
- Hypotension may occur after induction of anesthesia as a result of the combined effects of vasodilation and hypovolemia and should be treated with an -adrenergic agonist and volume infusion if necessary.
- In head injury a slight elevation of the head will improve venous drainage and decrease intracranial pressure.
- Regional anesthesia and deep general anesthesia are effective in preventing hyperreflexia.
Last modified: Sunday, 20 November 2016, 11:11 AM