Managing head injuries.

Abstract

The patient who presents with a serious head injury is often very difficult to manage. The airways is of primary concern; adequate ventilation must be provided and aspiration protected against. Recent studies suggest that hyperventilation may be as beneficial as was earlier believed. As the pCO2 level decreases, vasoconstriction occurs. If the level falls too low, cerebral perfusion is restricted, and profound cerebral anoxia may ensue. Current standards call for a ventilatory rate to allow for moderate respiratory alkalosis, in theory to mildly constrict teh vessels but still provide adequate perfusion. Arterial blood gas analysis in the ED is the definitive measurement of airway management in the field. Remember that the anatomy of the meningeal layers places the arteries primarily in the epidural space and the veins in the subdural space. A bleed in the epidural space often presents with a rapid onset of signs and symptoms, as was obvious in this traumatized patient. When a bleed occurs in the subdural space, the onset is usually more insidious, and an accurate history is a key to field diagnosis. As the hemorrhage expands, compression displaces the brain within the cranial vault. This displacement causes pressure to be exerted on the medulla of the brainstem. Cushing's Traid is a result of this pressure on the medulla and is evidence by the pulse slowing while systolic blood pressure rises and respirations become ataxic. Vomiting is often associated, and as the bleed continues, herniation syndrome begins. Decorticate posturing is displayed, followed by decerebrate posturing if relief is not provided. It is important to distinguish between decorticate and decerebrate posturing. It is important to distinguish between decorticate and decerebrate posturing. An easy way to remember the differences is to picture the anatomy of the brain. The cerebral cortex lies above the cerebellum, so when a patient's arms flexed up toward the face , he is pointing to his "core" (de-cor-ticate). As the arms extend downward, he is pointing to his cerebellum(de-cere-brate). T o manage the head-injured patient, it is imperative to anticipate potential developments, as well as protect against underlying injuries that may not be fully evaluated until arrival at the ED. Cervical spine often accompany head injuries, and full spinal immobilization is a mandatory precaution in all presentations. With the expanding hematoma found on this patient's neck, vascular damage ws obvious and contributed to the suspicion of spinal injury. As the intracranial pressure rise, vomiting and seizures are common. Placement of an endotracheal tube and having suction equipment ready are the best tools to prevent against aspiration. It is possible to angle the long spine board 10-15 degrees, exercising caution to ensure the patient's spinal alignment is not manipulated during the process. Seizures are usually treated with anticonvulsants like Valium. When a seizure accompanies a head injury, it is a direct result of the increased intracranial pressure and has a generally poor response to Valium, as the underlying cause of the seizure still exists. In this case, the patient had a full neuromuscular blockade, and any seizure would not have been recognized as long as the paralytics were on board. Early notification to the ED is essential, reporting all findings and interventions. This can alert them and give them the opportunity to prepare specialized equipment, such as CT scanners, mechanical ventilators, etc. Also, consider transportation options and the length of time to definitive care, including neurosurgical evaluation. This patient needs to be seen in a trauma center capable of the most thorough evaluation and management. Evacuation by air ambulance may be the most appropriate method of transport.