Head and Face Injuries Flashcards Para 130

Overview

This briefing document summarizes the key anatomical structures of the head and face and outlines the assessment and management principles for various injuries affecting these regions, including soft tissue damage, fractures, eye and ear injuries, oral and dental trauma, anterior neck injuries, and head and traumatic brain injuries (TBIs). The information is crucial for prehospital providers to recognize potential life threats, initiate appropriate care, and ensure safe and timely transport of patients with these injuries.

Main Themes and Important Ideas/Facts

1. Anatomy as the Foundation for Understanding Injury

The document emphasizes the importance of understanding the complex anatomy of the head and face to comprehend injury mechanisms and potential complications.

•Head and Face Structures: The briefing details the layers of the scalp, the bones of the skull (cranial vault, floor, base, and facial bones), the blood supply of the face and anterior neck, the orbits, nose, mandible, TMJ, hyoid bone, eye structures (globe, nerves, lacrimal apparatus), ear structures (external, middle, inner), teeth, tongue, and anterior neck structures (cartilages, trachea, vessels, nerves). The skull has 28 bones in three anatomical groups. 22 bones in cranium and face. The cranial vault has 8 bones.

  • Blood supply of the face: Primarily through the external carotid artery, which branches into several arteries including the facial artery, maxillary artery, and superficial temporal artery, maxillary artery.

•Brain Protection: The brain is highlighted as the "most important organ in the body" requiring "maximum protection from injury" through soft and hard wrappings (scalp and skull). Dura mater is attatched to the inner wall of the skull. Arachnoid mater is the second meningeal layer. Pia mater is firmly adhered directly to the brain.

•Interconnectedness: The document implicitly shows how injuries to one area can impact others (e.g., facial fractures affecting the airway, neck injuries impacting cerebral perfusion).

2. Injury Mechanisms and Types

The briefing outlines common mechanisms and classifications of injuries to the head and face.

•Broad Categorization: Head and face injuries encompass maxillofacial, eye and ear, oral and dental, anterior neck, and head/traumatic brain injuries.

•Specific Fractures: Different types of skull fractures (linear, depressed, basilar, open) and their typical mechanisms are described. Nasal and mandibular fractures are highlighted as common facial injuries, often resulting from blunt force trauma. The orbital floor is noted as "thin and easily fractured."

•Soft Tissue Injuries: The importance of noting the "MOI, forces involved" in soft tissue injuries is stressed, with a focus on potential airway compromise and the risk of swallowing blood leading to vomiting.

  • Maxillofacial Fractures: Facial bones absorb energy of impact.

  • Nasal Fractures: Most common facial fracture.

  • Mandibular fractures and dislocations: Second to nasal fractures in frequency.

  • Assessment of facial injuries: It is not important to distinguish among the various maxillofacial fractures in the prehospital setting. Begin with protecting the cervical spine.

•Eye Injuries: Blunt trauma, penetrating trauma, and burns are identified as frequent causes of eye injuries (Ultraviolet light, chemical burns, strong acid or alkali, never use any chemical antidotes). If there is a laceration to the globe itself, do not apply pressure to the eye.

•Ear Injuries: Foreign bodies, blast injury, and diving-related barotrauma are mentioned as causes of eardrum rupture.

•Oral and Dental Injuries: Blunt mechanisms (MVCs, direct blows) and penetrating mechanisms (GSWs) are cited. Airway compromise is the "biggest danger."

•Anterior Neck Injuries: MVCs, hangings (blunt), and direct traumas are listed. Penetrating injuries carry risks of "massive hemorrhage" and "airway compromise."

•Traumatic Brain Injury (TBI): Classified as closed (blunt trauma, dura intact) or open (penetration, dura breached). Primary injury occurs at impact, while secondary injury involves edema, hemorrhage, increased ICP, ischemia, and hypoxia.

  • Scalp Lacerations: Rich blood supply and can lead to significant blood loss. Hypovolemic shock is more common in children.

  • 4 different types of skull Fractures: Linear, Depressed, Basilar, Open.

3. Recognizing Life-Threatening Conditions

The document emphasizes the need to identify and manage immediate threats to life.

•Airway Compromise: Highlighted as a significant concern in facial, oral, and neck injuries. The tongue is noted as the "greatest cause of airway obstructions." Maxillofacial fractures and distortion of the upper airway can complicate airway management.

•Hemorrhage: Massive bleeding is a risk in facial, oral, and particularly penetrating neck injuries. Open neck injuries can lead to air embolism in jugular veins, "occludes the flow of blood to lungs," requiring immediate sealing with an occlusive dressing.

  • Epidural Hemorrhage: 0.5-1.0% of all head injuries. Usually blow to head with linear fracture. Common at temporal bones. Middle meningeal artery. Pupil on side of hematoma fixed/dilated.

  • Subdural Hematoma: 5% of all head injuries. Rupture of veins bridging dura and cortex. Venous bleeding is slower to develop. Stoke like symptoms with Hx of trauma.

  • Intracerebral Hemorrhage: Penetration injury, rapid decelaration. Can occur with DAI. Frontal and temporal lobes most affected. High mortality rate.

  • Subarachnoid Hemorrhage: Bleeding into where CSF circulates. Sudden severe headaches. Increased ICP, decreased LOC. Posturing, vomiting, death.

•Increased Intracranial Pressure (ICP): Discussed in detail as a consequence of brain injury and hemorrhage. The Monro-Kellie doctrine explains the fixed volume within the cranium. (The sum of volumes of brain, CSF, and intracranial blood volume is constant) An increase in one should cause a decrease in one or both of the remaining two. Increased ICP "decreases brain perfusion." Signs and symptoms include vomiting, headache, altered LOC, seizures (early); hypertension, bradycardia, pupil changes, posturing, coma (late). CSF leaks from the nose or ears are a warning sign.

•Cerebral Perfusion Pressure (CPP): The importance of maintaining adequate CPP (MAP - ICP, minimum 60 mm Hg) to prevent cerebral ischemia is emphasized. Autoregulation and its potential to lead to fatal ICP increase are explained. Any patient with a risk for ICP a systolic pressure of at least 100-120 mm/hg is required. CPP = MAP - ICP. CPP: Increased blood flow increases ICP. ICP increases forces CSF out of the brain. Displaced CSF moves to spinal cord. Autoregulation leads to fatal ICP increase. CPP decreases brain ischemia results.

4. Assessment Principles

A systematic approach to assessment is crucial for effective management.

•General Assessment: Includes MOI, BSI, ABCs, and consideration for spinal stabilization.

•Facial Injuries: Focus on airway, bleeding, and signs/symptoms like "ecchymosis or deep laceration," "swelling, pain to palpation, crepitus," "dental malocclusions, facial asymmetry," and "impaired eye movement/vision." Prehospital distinction between specific maxillofacial fractures is deemed "not important."

•Eye Injuries: Evaluate orbital rim, eyelids, corneas, conjunctivae, and globes for specific signs. Assess ocular function including eye movements and visual acuity.

•Ear Injuries: Assessment in the field can be "difficult." Note any blood or CSF leakage.

•Oral and Dental Injuries: Assess for bleeding, loose or fractured teeth.

•Anterior Neck Injuries: Focus on ABCs and potential spinal injury.

•Head Injuries: LOC is "very significant" and should be assessed using AVPU and GCS, with frequent reassessments. Pupil assessment (size, shape, equality, reaction) is critical. ICP is estimated based on clinical presentation (posturing, abnormal pupils, hypertension/hypotension).

5. Management Priorities

Prehospital management focuses on stabilizing the patient and preventing further injury.

•Cervical Spine Immobilization: Mandatory in suspected head or neck injuries ("Begins with protecting the cervical spine"). Jaw thrust maneuver for airway management.

•Airway Management: Open and maintain a patent airway. Be prepared for suctioning due to blood and potential vomiting. Consider advanced airway management (intubation, cricothyrotomy if necessary). Provide 100% oxygen.

•Breathing Support: Assess rate, regularity, and depth. Assist with bag-valve-mask ventilation if inadequate. In cases of suspected herniation, controlled ventilation to an ETCO2 of 30-35 mm Hg may be indicated. Avoid routine hyperventilation.

•Circulation: Control major bleeding with direct pressure (avoid excessive pressure if skull fracture suspected). Establish large-bore IV access with normal saline or lactated Ringer's (avoid dextrose in severe head injury). Manage hypotension (may indicate other injuries besides isolated closed head injury) and hypertension (common in severe closed head injury, restrict fluids). Maintain systolic BP around 110 mm Hg in severe closed head injury with hypotension.

•Eye Injury Management: Never apply pressure or manipulate the globe. Cover exposed globes with moist sterile dressing and a protective shield (cover both eyes to limit movement). Elevate the head of the backboard 40º for hyphema or globe rupture. Irrigate chemical burns extensively with sterile water or saline (minimum 5 minutes for weak solutions, 20 minutes for strong acids/alkalis, flush from nasal side outwards). Stabilize impaled objects (do not remove).

•Ear Injury Management: Apply padded dressing for soft tissue injuries. Gently realign and bandage avulsed pinna (retrieve completely avulsed parts). Do not stop blood or CSF leakage; look for signs of skull fracture. Stabilize impaled objects.

•Oral and Dental Injury Management: Ensure airway patency (suction, remove fractured teeth/fragments). Position conscious patients to drain blood. Handle avulsed teeth by the crown, rinse gently (no scrubbing), and keep moist (reimplantation possible within one hour).

•Anterior Neck Injury Management: Focus on ABCs and cervical spine stabilization. Seal open neck wounds immediately with an occlusive dressing to prevent air embolism. Do not wrap bandages circumferentially.

•Head Injury Management: Maintain cerebral blood flow and mitigate ICP. Elevate the head of the backboard 30 degrees if no spinal injury contraindications. Avoid hyperventilation unless signs of herniation are present. Manage hyperpyrexia. Lightly cover open fractures with exposed brain with a sterile saline-moistened dressing. Apply loose sterile dressing to CSF leaks. Stabilize impaled objects.

6. Transport Considerations

Prompt and appropriate transport is critical.

•Trauma Center with Neurosurgical Capabilities: Patients with significant head and face injuries often require specialized care and surgery. Transport to the most appropriate facility, even if it means bypassing a closer hospital, is crucial.

Notable Quotes

•Brain Protection: "The brain – Most important organ in the body – Requires maximum protection from injury."

•Orbital Floor Fracture: "Orbital floor – Thin and easily fractured."

•Nasal Fractures: "Nasal bones are structurally unsound." "Most common facial fracture."

•Mandibular Fractures: "Second only to nasal fractures in frequency."

•Prehospital Facial Fracture Assessment: "It is not important to distinguish among the various maxillofacial fractures in the prehospital setting."

•Airway in Oral Injuries: "Biggest danger: airway compromise."

•Tongue as Obstruction: "Greatest cause of airway obstructions."

•Neck Air Embolism: "Jugular veins entrain air into vessel – Occludes the flow of blood to lungs."

•Increased ICP and Perfusion: "Increased ICP decreases brain perfusion."

•CPP Threshold: "Critical minimum threshold is 60 mm Hg."

•LOC Significance: "LOC changes are very significant. – LOC = extent of brain dysfunction."

•Hyperventilation Caution: "Avoid routine hyperventilation."

•Transport Destination: "Patient often needs immediate surgery – Transport to a facility – That has a trauma centre – That has neurosurgical capabilities – This means you may bypass the nearest hospital."

Conclusion

Effective management of head and face injuries requires a strong understanding of the underlying anatomy, recognition of injury mechanisms and potential complications, a systematic approach to assessment, and prioritized interventions focused on maintaining the airway, supporting breathing and circulation, preventing secondary brain injury, and ensuring timely transport to an appropriate medical facility. Prehospital providers play a vital role in improving outcomes for patients with these potentially devastating injuries.