NEET MDS Lessons
General Surgery
Advanced Trauma Life Support (ATLS)
Introduction
Trauma is a leading cause of death, particularly in the first four decades of life, and ranks as the third most common cause of death overall. The Advanced Trauma Life Support (ATLS) program was developed to provide a systematic approach to the management of trauma patients, ensuring that life-threatening conditions are identified and treated promptly.
Mechanisms of Injury
In trauma, injuries can be classified based on their mechanisms:
Overt Mechanisms
- Penetrating Trauma: Injuries caused by objects that penetrate the skin and underlying tissues.
- Blunt Trauma: Injuries resulting from impact without penetration, such as collisions or falls.
- Thermal Trauma: Injuries caused by heat, including burns.
- Blast Injury: Injuries resulting from explosions, which can cause a combination of blunt and penetrating injuries.
Covert Mechanisms
- Blunt Trauma: Often results in internal injuries that may not be immediately apparent.
- Penetrating Trauma: Can include knife wounds and other sharp objects.
- Penetrating Knife: Specific injuries from stabbing.
- Gunshot Injury: Injuries caused by firearms, which can have extensive internal damage.
The track of penetrating injuries can often be identified by the anatomy involved, helping to determine which organs may be injured.
Steps in ATLS
The ATLS protocol consists of a systematic approach to trauma management, divided into two main surveys:
1. Primary Survey
- Objective: Identify and treat life-threatening conditions.
- Components:
- A - Airway: Ensure the airway is patent. In patients with a Glasgow Coma Scale (GCS) of 8 or less, immediate intubation is necessary. Maintain cervical spine stability.
- B - Breathing: Assess ventilation and oxygenation. Administer high-flow oxygen via a reservoir mask. Identify and treat conditions such as tension pneumothorax, flail chest, massive hemothorax, and open pneumothorax.
- C - Circulation: Evaluate circulation based on:
- Conscious level (indicates cerebral perfusion)
- Skin color
- Rapid, thready pulse (more reliable than blood pressure)
- D - Disability: Assess neurological status using the Glasgow Coma Scale (GCS).
- E - Exposure: Fully expose the patient to assess for injuries on the front and back.
2. Secondary Survey
- Objective: Conduct a thorough head-to-toe examination to identify all injuries.
- Components:
- AMPLE: A mnemonic to gather important patient
history:
- A - Allergy: Any known allergies.
- M - Medications: Current medications the patient is taking.
- P - Past Medical History: Relevant medical history.
- L - Last Meal: When the patient last ate.
- E - Events of Incident: Details about the mechanism of injury.
- AMPLE: A mnemonic to gather important patient
history:
Triage
Triage is the process of sorting patients based on the severity of their condition. The term "triage" comes from the French word meaning "to sort." In trauma settings, patients are categorized using a color-coded system:
- Red: First priority (critical patients, e.g., tension pneumothorax).
- Yellow: Second priority (urgent cases, e.g., pelvic fracture).
- Green: Third priority (minor injuries, e.g., simple fracture).
- Black: Zero priority (patients who are dead or unsalvageable).
Blunt Trauma
- Common Causes: The most frequent cause of blunt trauma is road traffic accidents.
- Seat Belt Use: Wearing seat belts significantly reduces
mortality rates:
- Front row occupants: 45% reduction in death rate.
- Rear seat belt use: 80% reduction in death rate for front seat occupants.
- Seat Belt Injuries: Marks on the thorax indicate a fourfold increase in thoracic injuries, while abdominal marks indicate a threefold increase in abdominal injuries.
Radiographs in Trauma
Key radiographic views to obtain in trauma cases include:
- Lateral cervical spine
- Anteroposterior chest
- Anteroposterior pelvis
Suture Materials
Sutures are essential in surgical procedures for wound closure and tissue approximation. Various types of sutures are available, each with unique properties, advantages, and applications. Below is a summary of some commonly used suture materials, including chromic catgut, polypropylene, polyglycolic acid, and polyamide (nylon).
1. Chromic Catgut
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Description:
- Chromic catgut is a natural absorbable suture made from collagen derived from the submucosa of sheep intestines or the serosa of beef cattle intestines. It is over 99% pure collagen.
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Absorption Process:
- The absorption of chromic catgut occurs through enzymatic digestion by proteolytic enzymes, which are derived from lysozymes contained within polymorphonuclear leukocytes (polymorphs) and macrophages.
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Absorption Rate:
- The absorption rate depends on the size of the suture and whether it is plain or chromicized. Typically, absorption is completed within 60-120 days.
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Applications:
- Commonly used in soft tissue approximation and ligation, particularly in areas where a temporary support is needed.
2. Polypropylene (Proline)
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Description:
- Polypropylene is a synthetic monofilament suture made from a purified and dyed polymer.
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Properties:
- It has an extremely high tensile strength, which it retains indefinitely after implantation. Polypropylene is non-biodegradable, meaning it does not break down in the body.
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Applications:
- Ideal for use in situations where long-term support is required, such as in vascular surgery, hernia repairs, and other procedures where permanent sutures are beneficial.
3. Polyglycolic Acid
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Description:
- Polyglycolic acid is a synthetic absorbable suture formed by linking glycolic acid monomers to create a polymer.
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Properties:
- It is known for its predictable absorption rate and is commonly used in various surgical applications.
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Applications:
- Frequently used in soft tissue approximation, including in gastrointestinal and gynecological surgeries, where absorbable sutures are preferred.
4. Polyamide (Nylon)
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Description:
- Polyamide, commonly known as nylon, is a synthetic non-absorbable suture that is chemically extruded and generally available in monofilament form.
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Properties:
- Nylon sutures have a low coefficient of friction, making passage through tissue easy. They also elicit minimal tissue reaction.
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Applications:
- Used in a variety of surgical procedures, including skin closure, where a strong, durable suture is required.
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:
- Acute Upper Airway Obstruction: Conditions such as severe allergic reactions, infections (e.g., epiglottitis), or trauma that obstruct the airway.
- Major Surgery: Procedures involving the mouth, pharynx, or larynx that may compromise the airway.
- Prolonged Mechanical Ventilation: Patients requiring artificial ventilation for an extended period, such as those with respiratory failure.
- 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.