There are two main types of intracranial bleeds discussed: subdural and epidural.
Subdural Hematomas
Definition: Slow venous bleeding that occurs in the brain, often between the brain surface and outer covering (dura mater).
Symptoms:
Patients may initially exhibit normal mental acuity.
Changes in mental state can be lucidity followed by drowsiness, then coma, often without noticeable progression.
Often, patients declare they feel fine, leading to a false sense of security.
Mechanism of Death:
Typically occurs when the rate of blood accumulation exceeds reabsorption rate overnight, leading to pressure in the brain.
Prone Populations:
Elderly patients are particularly prone due to:
Brain shrinkage with age.
Decreased production of cerebrospinal fluid (CSF) leading to a tighter space for the subarachnoid veins, increasing likelihood of tearing during falls.
Epidural Hematomas
Definition: Arterial bleeding that is more aggressive than subdural bleeding due to rapid accumulation of blood.
Symptoms:
Deterioration of patient conditions can occur swiftly, often within minutes.
Patients may lose consciousness relatively quickly after injury.
Mechanism of Bleed:
The bleeding occurs rapidly (minutes), usually from a head trauma that ruptures an artery, thus producing dramatic symptoms.
Key Differences Between Subdural and Epidural Bleeds
Speed of Deterioration:
Epidural: Minutes
Subdural: 12 to 24 hours
Nature of Blood Accumulation:
Epidural: Rapid and aggressive (arterial bleeding)
Subdural: Slow and insidious (venous bleeding)
Treatment Approaches
Epidural Hematoma Treatment:
Involves a surgical procedure using a drill to access the bleed.
Care must be taken with the drilling technique to avoid further brain damage.
Insertion of a one-way valve to control intracranial pressure, followed by transfer to a neurosurgeon for further management.
Emergency Response Context:
Patients should be transported to a level one trauma center for the best care from neurosurgeons.
Vital Signs and Symptoms Assessment
Differentiating Signs:
Bounding pulse: Indicative of increased intracranial pressure (not hypotension like in shock).
Thready pulse: Often associated with shock states, indicative of reduced blood pressure.
General Clinical Principles
Initial Patient Assessment:
Always assess the mechanism of injury and patient age, particularly with head injuries.
Be cautious with patients showing lucidity post-injury, as they may decline further medical evaluation.
Management Focus:
Ensure airway management and provide respiratory support if necessary, as patients may show seizure activity due to increased pressure.
Rapid transport is crucial as timing can determine survival rates.
Special Cases: Subarachnoid Hemorrhage
Common Symptoms:
Severe headache (thunderclap headache) described as if a bomb exploded in the skull.
Changes in pupil size and response can indicate serious neurological issues.
Midpoint and dilated pupils can suggest potential bleeding locations within the brain.
Key Takeaways for Examination Preparation
Difference in Bleeds: Be prepared to identify and differentiate the types of bleeds based on symptoms and mechanisms.
Importance of Rapid Response: Understand the critical first-response measures and the importance of transporting patients to a higher-level trauma center.