Talk to us?

General Surgery - NEETMDS- courses
NEET MDS Lessons
General Surgery

Types of Brain Injury

Brain injuries can be classified into two main categories: primary and secondary injuries. Understanding these types is crucial for effective diagnosis and management.

1. Primary Brain Injury

  • Definition: Primary brain injury occurs at the moment of impact. It results from the initial mechanical forces applied to the brain and can lead to immediate damage.
  • Examples:
    • Contusions: Bruising of brain tissue.
    • Lacerations: Tears in brain tissue.
    • Concussions: A temporary loss of function due to trauma.
    • Diffuse axonal injury: Widespread damage to the brain's white matter.

2. Secondary Brain Injury

  • Definition: Secondary brain injury occurs after the initial impact and is often preventable. It results from a cascade of physiological processes that can exacerbate the initial injury.
  • Principal Causes:
    • Hypoxia: Reduced oxygen supply to the brain, which can worsen brain injury.
    • Hypotension: Low blood pressure can lead to inadequate cerebral perfusion.
    • Raised Intracranial Pressure (ICP): Increased pressure within the skull can compress brain tissue and reduce blood flow.
    • Reduced Cerebral Perfusion Pressure (CPP): Insufficient blood flow to the brain can lead to ischemia.
    • Pyrexia: Elevated body temperature can increase metabolic demands and worsen brain injury.

Glasgow Coma Scale (GCS)

The Glasgow Coma Scale is a clinical tool used to assess a patient's level of consciousness and neurological function. It consists of three components: eye opening, verbal response, and motor response.

Eye Opening (E)

  • Spontaneous: 4
  • To verbal command: 3
  • To pain stimuli: 2
  • No eye opening: 1

Verbal Response (V)

  • Normal, oriented: 5
  • Confused: 4
  • Inappropriate words: 3
  • Sounds only: 2
  • No sounds: 1

Motor Response (M)

  • Obeys commands: 6
  • Localizes to pain: 5
  • Withdrawal flexion: 4
  • Abnormal flexion (decorticate): 3
  • Extension (decerebrate): 2
  • No motor response: 1

Scoring

  • Best Possible Score: 15/15 (fully alert and oriented)
  • Worst Possible Score: 3/15 (deep coma or death)
  • Intubated Cases: For patients who are intubated, the verbal score is recorded as "T."
  • Intubation Indication: Intubation should be performed if the GCS score is less than or equal to 8.

Additional Assessments

Pupil Examination

  • Pupil Reflex: Assess size and light response.
  • Uncal Herniation: In cases of mass effect on the ipsilateral side, partial third nerve dysfunction may be noted, characterized by a larger pupil with sluggish reflex.
  • Hutchinson Pupil: As third nerve compromise increases, the ipsilateral pupil may become fixed and dilated.

Signs of Base of Skull Fracture

  • Raccoon Eyes: Bilateral periorbital hematoma, indicating possible skull base fracture.
  • Battle’s Sign: Bruising over the mastoid process, suggesting a fracture of the temporal bone.
  • CSF Rhinorrhea or Otorrhea: Leakage of cerebrospinal fluid from the nose or ear, indicating a breach in the skull base.
  • Hemotympanum: Blood in the tympanic cavity, often seen with ear bleeding.

Tracheostomy

Tracheostomy is a surgical procedure that involves creating an opening in the trachea (windpipe) to facilitate breathing. This procedure is typically performed when there is a need for prolonged airway access, especially in cases where the upper airway is obstructed or compromised. The incision is usually made between the 2nd and 4th tracheal rings, as entry through the 1st ring can lead to complications such as tracheal stenosis.

Indications

Tracheostomy may be indicated in various clinical scenarios, including:

  1. Acute Upper Airway Obstruction: Conditions such as severe allergic reactions, infections (e.g., epiglottitis), or trauma that obstruct the airway.
  2. Major Surgery: Procedures involving the mouth, pharynx, or larynx that may compromise the airway.
  3. Prolonged Mechanical Ventilation: Patients requiring artificial ventilation for an extended period, such as those with respiratory failure.
  4. Unconscious Patients: Situations involving head injuries, tetanus, or bulbar poliomyelitis where airway protection is necessary.

Procedure

Technique

  • Incision: A horizontal incision is made in the skin over the trachea, typically between the 2nd and 4th tracheal rings.
  • Dissection: The subcutaneous tissue and muscles are dissected to expose the trachea.
  • Tracheal Entry: An incision is made in the trachea, and a tracheostomy tube is inserted to maintain the airway.

Complications of Tracheostomy

Tracheostomy can be associated with several complications, which can be categorized into intraoperative, early postoperative, and late postoperative complications.

1. Intraoperative Complications

  • Hemorrhage: Bleeding can occur during the procedure, particularly if major blood vessels are inadvertently injured.
  • Injury to Paratracheal Structures:
    • Carotid Artery: Injury can lead to significant hemorrhage and potential airway compromise.
    • Recurrent Laryngeal Nerve: Damage can result in vocal cord paralysis and hoarseness.
    • Esophagus: Injury can lead to tracheoesophageal fistula formation.
    • Trachea: Improper technique can cause tracheal injury.

2. Early Postoperative Complications

  • Apnea: Temporary cessation of breathing may occur, especially in patients with pre-existing respiratory issues.
  • Hemorrhage: Postoperative bleeding can occur, requiring surgical intervention.
  • Subcutaneous Emphysema: Air can escape into the subcutaneous tissue, leading to swelling and discomfort.
  • Pneumomediastinum and Pneumothorax: Air can enter the mediastinum or pleural space, leading to respiratory distress.
  • Infection: Risk of infection at the incision site or within the tracheostomy tube.

3. Late Postoperative Complications

  • Difficult Decannulation: Challenges in removing the tracheostomy tube due to airway swelling or other factors.
  • Tracheocutaneous Fistula: An abnormal connection between the trachea and the skin, which may require surgical repair.
  • Tracheoesophageal Fistula: An abnormal connection between the trachea and esophagus, leading to aspiration and feeding difficulties.
  • Tracheoinnominate Arterial Fistula: A rare but life-threatening complication where the trachea erodes into the innominate artery, resulting in severe hemorrhage.
  • Tracheal Stenosis: Narrowing of the trachea due to scar tissue formation, which can lead to breathing difficulties.

SHOCK

Shock  is  defined  as  a  pathological  state  causing  inadequate  oxygen  delivery  to  the peripheral tissues and resulting in lactic acidosis, cellular hypoxia and disruption of normal metabolic condition.

CLASSIFICATION

Shock is generally classified into three major categories:

1.    Hypovolemic shock

2.    Cardiogenic shock

3.    Distributive shock

Distributive shock is further subdivided into three subgroups:

a.    Septic shock

b.    Neurogenic shock

c.    Anaphylactic shock

Hypovolemic  shock  is  present  when  marked  reduction  in  oxygen  delivery results from diminished cardiac output secondary to inadequate vascular volume. In general, it results from loss of fluid from circulation, either directly or indirectly.
e.g.    ?    Hemorrhage
    •    Loss of plasma due to burns
    •    Loss of water and electrolytes in diarrhea
    •    Third space loss (Internal fluid shift into inflammatory exudates in
        the peritoneum, such as in pancreatitis.)

Cardiogenic shock is present when there is severe reduction in oxygen delivery secondary to impaired cardiac function. Usually it is due to myocardial infarction or pericardial tamponade.

Septic Shock (vasogenic shock) develops as a result of the systemic effect of infection. It is the result of a septicemia with endotoxin and exotoxin release by gram-negative and gram-positive bacteria. Despite normal or increased cardiac output and oxygen delivery, cellular oxygen consumption is less than normal due to impaired extraction as a result of impaired metabolism.

Neurogenic shock results primarily from the disruption of the sympathetic nervous system which may be due to pain or loss of sympathetic tone, as in spinal cord injuries.

PATHO PHYSIOLOGY OF SHOCK

Shock stimulates a physiologic response. This circulatory response to hypotension is to conserve perfusion to the vital organs (heart and brain) at the expense of other tissues. Progressive vasoconstriction of skin, splanchnic and renal vessels leads to renal cortical necrosis and acute renal failure. If not corrected in time, shock leads to organ failure and sets up a vicious circle with hypoxia and acidosis.

CLINICAL FEATURES

The clinical presentation varies according to the cause. But in general patients with hypotension and reduced tissue perfusion presents with:
•    Tachycardia
•    Feeble pulse
•    Narrow pulse pressure
•    Cold extremities (except septic shock)
•    Sweating, anxiety
•    Breathlessness / Hyperventilation
•    Confusion leading to unconscious state

PATHO PHYSIOLOGY OF SHOCK

Shock stimulates a physiologic response. This circulatory response to hypotension is to conserve perfusion to the vital organs (heart and brain) at the expense of other tissues. Progressive vasoconstriction of skin, splanchnic and renal vessels leads to renal cortical necrosis and acute renal failure. If not corrected in time, shock leads to organ failure and sets up a vicious circle with hypoxia and acidosis.

CLINICAL FEATURES

The clinical presentation varies according to the cause. But in general patients with hypotension and reduced tissue perfusion presents with:
•    Tachycardia
•    Feeble pulse
•    Narrow pulse pressure
•    Cold extremities (except septic shock)
•    Sweating, anxiety
•    Breathlessness / Hyperventilation
•    Confusion leading to unconscious state

Ludwig's Angina

Ludwig's angina is a serious, potentially life-threatening cellulitis or connective tissue infection of the submandibular space. It typically arises from infections of the teeth, particularly the second or third molars, and can lead to airway obstruction due to swelling. This condition is named after the German physician Wilhelm Friedrich von Ludwig, who first described it in the 19th century.

Etiology

  • Common Causes:

    • Dental infections (especially from the lower molars)
    • Infections from the floor of the mouth
    • Trauma to the submandibular area
    • Occasionally, infections can arise from other sources, such as the oropharynx or skin.
  • Microbial Agents:

    • Mixed flora, including both aerobic and anaerobic bacteria.
    • Common organisms include Streptococcus, Staphylococcus, and Bacteroides species.

Pathophysiology

  • The infection typically begins in the submandibular space and can spread rapidly due to the loose connective tissue in this area.
  • The swelling can lead to displacement of the tongue and can obstruct the airway, making it a medical emergency.

Clinical Presentation

  • Symptoms:

    • Swelling of the submandibular area, which may be bilateral
    • "Brawny induration" (firm, non-fluctuant swelling)
    • Pain and tenderness in the submandibular region
    • Difficulty swallowing (dysphagia) and speaking (dysarthria)
    • Fever and malaise
    • Possible elevation of the floor of the mouth and displacement of the tongue
  • Signs:

    • Swelling may extend to the neck and may cause "bull neck" appearance.
    • Trismus (limited mouth opening) may be present.
    • Respiratory distress due to airway compromise.

Diagnosis

  • Clinical Evaluation: Diagnosis is primarily clinical based on history and physical examination.
  • Imaging:
    • CT scan of the neck may be used to assess the extent of the infection and to rule out other conditions.
    • X-rays may show air in the soft tissues if there is a necrotizing infection.

Management

Initial Management

  • Airway Management:
    • Ensure the airway is patent; this may require intubation or tracheostomy in severe cases.

Medical Treatment

  • Antibiotics:
    • Broad-spectrum intravenous antibiotics are initiated to cover both aerobic and anaerobic bacteria. Common regimens may include:
      • Ampicillin-sulbactam
      • Clindamycin
      • Metronidazole combined with a penicillin derivative

Surgical Intervention

  • Drainage:
    • Surgical drainage may be necessary if there is an abscess formation or significant swelling.
    • Incisions are typically made in the submandibular area to allow for drainage of pus and to relieve pressure.

Complications

  • Airway Obstruction: The most critical complication, requiring immediate intervention.
  • Sepsis: Can occur if the infection spreads systemically.
  • Necrotizing fasciitis: Rare but serious complication that may require extensive surgical intervention.
  • Thrombosis of the internal jugular vein: Can occur due to the spread of infection.

Prognosis

  • With prompt diagnosis and treatment, the prognosis is generally good. However, delays in management can lead to significant morbidity and mortality due to airway compromise and systemic infection.

Excision of Lesions Involving the Jaw Bone

When excising lesions involving the jaw bone, various terminologies are used to describe the specific techniques and outcomes of the procedures.

1. Enucleation

  • Enucleation refers to the separation of a lesion from the bone while preserving bone continuity. This is achieved by removing the lesion along an apparent tissue or cleavage plane, which is often defined by an encapsulating or circumscribing connective tissue envelope derived from the lesion or surrounding bone.
  • Key Characteristics:
    • The lesion is contained within a defined envelope.
    • Bone continuity is maintained post-excision.

2. Curettage

  • Curettage involves the removal of a lesion from the bone by scraping, particularly when the lesion is friable or lacks an intact encapsulating tissue envelope. This technique may result in the removal of some surrounding bone.
  • Key Characteristics:
    • Indicates the inability to separate the lesion along a distinct tissue plane.
    • May involve an inexact or immeasurable thickness of surrounding bone.
    • If a measurable margin of bone is removed, it is termed "resection without continuity defect."

3. Marsupialization

  • Marsupialization is a surgical procedure that involves the exteriorization of a lesion by removing overlying tissue to expose its internal surface. This is done by excising a portion of the lesion bordering the oral cavity or another body cavity.
  • Key Characteristics:
    • Multicompartmented lesions are rendered unicompartmental.
    • The lesion is clinically cystic, and the excised tissue may include bone and/or overlying mucosa.

4. Resection Without Continuity Defect

  • This term describes the excision of a lesion along with a measurable perimeter of investing bone, without interrupting bone continuity. The anatomical relationship allows for the removal of the lesion while preserving the integrity of the bone.
  • Key Characteristics:
    • Bone continuity is maintained.
    • Adjacent soft tissue may be included in the resection.

5. Resection With Continuity Defect

  •  This involves the excision of a lesion that results in a defect in the continuity of the bone. This is often associated with more extensive resections.
  • Key Characteristics:
    • Bone continuity is interrupted.
    • May require reconstruction or other interventions to restore function.

6. Disarticulation

  •  Disarticulation is a special form of resection that involves the temporomandibular joint (TMJ) and results in a continuity defect.
  • Key Characteristics:
    • Involves the removal of the joint and associated structures.
    • Results in loss of continuity in the jaw structure.

7. Recontouring

  •  Recontouring refers to the surgical reduction of the size and/or shape of the surface of a bony lesion or bone part. The goal is to reshape the bone to conform to the adjacent normal bone surface or to achieve an aesthetic result.
  • Key Characteristics:
    • May involve lesions such as bone hyperplasia, torus, or exostosis.
    • Can be performed with or without complete eradication of the lesion (e.g., fibrous dysplasia).

An ulcer is a break in the continuity of the skin or the mucous membrane.

Mode of onset:  Traumatic ulcers heal when the traumatic agent is removed., If it persists it becomes chronic as in the case of dental ulcer of the tongue. Ulcers may develop spontaneously as in the case of gumma (syphilitic ulcer). It may develop with varicose veins called varicose ulcer, which develops in the lower third of the leg.

Sometimes a malignant ulcer develops in a scar called Marjolin’s ulcer. Special features are:

 No pain - as there are no nerves. It does not spread - as there is scar tissue. No metastases - as there are no lymphatics Treatment:- Wide excision.

Classification of Ulcer

A) Pathologically

I. Non-specific ulcers:

a. Due to infected wound after trauma, that is physical or chemical agents.

b. Due to local infection example dental ulcer, pressure sore

 Specific ulcers: Caused by specific infection

a. Syphilitic ulcers (Hunterian chancre)

b. Tubercular  ulcers, actinomycosis

Trophic ulcer:- Caused by two factors:

Diminished nutrition due to inadequate blood supply to the tissues

Eg. Ulcers in Buerger’s Disease, Artherosclerosis

b. Diminished or absence of sensation of the skin leading to perforating ulcer of the foot

iv. Malignant ulcer: Due to squamous cell carcinoma, rodent ulcers and melanoma.

B) Clinical classification of ulcers

1. Acute Ulcer:  The edge is inflamed oedematous and painful with slough in the floor and n o granulation tissue. Profuse purulent Discgarge seen

2. Healing ulcers: edge sloping with bluish margin The floor is covered with a red, healthy granulation tissue.

3. Chronic or callous ulcer (non- healing) There is no tendency to heal by itself, the base is jndurated  unhealthy granulation tissue is present in the floor The edge is rounded and thickened.

Chronic ulcer occur due to:

Chronic infection , Defective circulation , Foreign body, Persistent local oedema , Malignancy , Diabetes , Malnutrition (loss of proteins), Gout

Specific Ulcers

Tubeculous Ulcer

Edge Undermined, floor contains granulation tissue a watery discharge is present. Caseous material is found in the floor of the ulcer. It usually occurs in tubercular lymphadenitis in the neck, axilla or groin.

Syphilitic Ulcer

a) Huntarian Chancre or  primary sore or hard chancre: usuaIly occurs over the genitalia especially on penis. Occurs in the primary stage of syphilis Ulcer is round or oval, it is hard,indurated, elevated and painless It feels like a button, discharges serum containing spirochetes (cork screw) which is highly infective.

b) In the Secondary stage mucous patches and condylomata occurs The ulcers are shallow white patches, of sodden thickness which occur in the mouth and tongue. Condyloma are hypertrophied epithelium with serous discharge occurring in mucocutaneous junction around the anus. The regional lymphnod (inguinal transverse chain) are enlarged.

c) In tertiary stage of syphilis gummatous ulcers occur They have a punched  out edge and wash Ieather floor. They occur on the subcutaneous bones like sternum and tibia. They are painless and refuse to heal.

Soft Sore (chanchroid)

They are painful muitiple ulcers, with copious discharge. They are caused by Bacillus Ducrey  lncubation time is 3 to 4 days. located on glans penis and prepuce is due to venereal infection. They are associated with enlarged called bilateral inguinal lymphnodes

Tropical ulcer:

a) Oriental Sore - due to L. Tropica (lieshmaniasis)

b) Ulcers and sinuses are due to guinea worm abscess

c) Histoplasmosis with multiple ulcers on the tibia.

d) Chronic ulcers due to yaws

e) Amoebic ulcers occur in colon_and rectum , flask shaped ulcers , undermined edge , caused by  Entamoeba Histolytica

Varicose Ulcer:

Associated with varicose veins. Occurs on the inner aspect of the lower third of leg , chronic ulcer The surrounding area is pigmented and eczema is present. The sore is longitudinally oval It does not penetrate the deep fascia and is painless The base is adherent to the periosteum of the tibia

Rodent ulcer

Usually Occurs on the face above a line joining the lobule of the ear to the angle of the mouth. Usually occurs at the inner canthous of the eye . Edge is raised and rolled, Erodes the deeper structures and the bone, the lyrnph nodes are not involved.

Treatment: If small wide excision is done with skin grafting, If large, radiotherapy is given.

Malignant Ulcer

Occurs due to chronic irritation as in the case of malignant ulcer of the tongue. The edge is everted. The floor is covered with slough and tumor tissue The regional lymph nodes are hard.

Initially mobile later becomes hard

Treatment: Wide excision is done.

Marjolin ulcer: Malignant Ulcer occurring on scar of Burns

Intubation

Intubation is a critical procedure in airway management, and the choice of technique—oral intubation, nasal intubation, or tracheostomy—depends on the clinical situation, patient anatomy, and specific indications or contraindications. 

Indications for Each Intubation Technique

1. Oral Intubation

Oral intubation is often the preferred method in emergency situations and when nasal intubation is contraindicated. Indications include:

  • Emergent Intubation: Situations such as cardiopulmonary resuscitation (CPR), unconsciousness, or apnea.
  • Oral or Mandibular Trauma: When there is significant trauma to the oral cavity or mandible that may complicate nasal access.
  • Cervical Spine Conditions: Conditions such as ankylosis, arthritis, or trauma that may limit neck movement.
  • Gagging and Vomiting: In patients who are unable to protect their airway due to these conditions.
  • Agitation: In cases where the patient is agitated and requires sedation and airway protection.

2. Nasal Intubation

Nasal intubation is indicated in specific situations where oral intubation may be difficult or impossible. Indications include:

  • Nasal Obstruction: When there is a blockage in the oral route.
  • Paranasal Disease: Conditions affecting the nasal passages that may necessitate nasal access.
  • Awake Intubation: In cases where the patient is cooperative and can tolerate the procedure.
  • Short (Bull) Neck: In patients with anatomical challenges that make oral intubation difficult.

3. Tracheostomy

Tracheostomy is indicated for long-term airway management or when other methods are not feasible. Indications include:

  • Inability to Insert Translational Tube: When oral or nasal intubation fails or is not possible.
  • Need for Long-Term Definitive Airway: In patients requiring prolonged mechanical ventilation or airway support.
  • Obstruction Above Cricoid Cartilage: Conditions that obstruct the airway at or above the cricoid level.
  • Complications of Translational Intubation: Such as glottic incompetence or inability to clear tracheobronchial secretions.
  • Sleep Apnea Unresponsive to CPAP: In patients with severe obstructive sleep apnea who do not respond to continuous positive airway pressure (CPAP) therapy.
  • Facial or Laryngeal Trauma: Structural contraindications to translaryngeal intubation.

 

Contraindications for Nasal Intubation

  • Severe Fractures of the Midface: Nasal intubation is contraindicated due to the risk of further injury and complications.
  • Nasal Fractures: Similar to midface fractures, nasal fractures can complicate nasal intubation and increase the risk of injury.
  • Basilar Skull Fractures: The risk of entering the cranial cavity or causing cerebrospinal fluid (CSF) leaks makes nasal intubation unsafe in these cases.
  • Contraindications for Oral Intubation

    1. Severe Facial or Oral Trauma:

      • Significant injuries to the face, jaw, or oral cavity may make oral intubation difficult or impossible and increase the risk of further injury.
    2. Obstruction of the Oral Cavity:

      • Conditions such as large tumors, severe swelling, or foreign bodies that obstruct the oral cavity can prevent successful intubation.
    3. Cervical Spine Instability:

      • Patients with unstable cervical spine injuries may be at risk of further injury if neck extension is required for intubation.
    4. Severe Maxillofacial Deformities:

      • Anatomical abnormalities that prevent proper visualization of the airway or access to the trachea.
    5. Inability to Open the Mouth:

      • Conditions such as trismus (lockjaw) or severe oral infections that limit mouth opening can hinder intubation.
    6. Severe Coagulopathy:

      • Patients with bleeding disorders may be at increased risk of bleeding during the procedure.
    7. Anticipated Difficult Airway:

      • In cases where the airway is expected to be difficult to manage, alternative methods may be preferred.

 

Contraindications for Tracheostomy

  1. Severe Coagulopathy:

    • Patients with significant bleeding disorders may be at risk for excessive bleeding during the procedure.
  2. Infection at the Site of Incision:

    • Active infections in the neck or tracheostomy site can increase the risk of complications and should be addressed before proceeding.
  3. Anatomical Abnormalities:

    • Significant anatomical variations or deformities in the neck that may complicate the procedure or increase the risk of injury to surrounding structures.
  4. Severe Respiratory Distress:

    • In some cases, if a patient is in severe respiratory distress, immediate intubation may be prioritized over tracheostomy.
  5. Patient Refusal:

    • If the patient is conscious and refuses the procedure, it should not be performed unless there is an immediate life-threatening situation.
  6. Inability to Maintain Ventilation:

    • If the patient cannot be adequately ventilated through other means, tracheostomy may be necessary, but it should be performed with caution.
  7. Unstable Hemodynamics:

    • Patients with severe hemodynamic instability may not tolerate the procedure well, and alternative airway management strategies may be required.

Explore by Exams