NEET MDS Lessons
General Surgery
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.
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
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.
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.
Walsham’s Forceps
Walsham’s forceps are specialized surgical instruments used primarily in the manipulation and reduction of fractured nasal fragments. They are particularly useful in the management of nasal fractures, allowing for precise adjustment and stabilization of the bone fragments during the reduction process.
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Design:
- Curved Blades: Walsham’s forceps feature two curved blades—one padded and one unpadded. The curvature of the blades allows for better access and manipulation of the nasal structures.
- Padded Blade: The padded blade is designed to provide a gentle grip on the external surface of the nasal bone and surrounding tissues, minimizing trauma during manipulation.
- Unpadded Blade: The unpadded blade is inserted into the nostril and is used to secure the internal aspect of the nasal bone and associated fragments.
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Usage:
- Insertion: The unpadded blade is carefully passed up the nostril to reach the fractured nasal bone and the associated fragment of the frontal process of the maxilla.
- Securing Fragments: Once in position, the nasal bone and the associated fragment are secured between the padded blade externally and the unpadded blade internally.
- Manipulation: The surgeon can then manipulate the fragments into their correct anatomical position, ensuring proper alignment and stabilization.
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Indications:
- Walsham’s forceps are indicated for use in cases of nasal fractures, particularly when there is displacement of the nasal bones or associated structures. They are commonly used in both emergency and elective settings for nasal fracture management.
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Advantages:
- Precision: The design of the forceps allows for precise manipulation of the nasal fragments, which is crucial for achieving optimal alignment and aesthetic outcomes.
- Minimized Trauma: The padded blade helps to reduce trauma to the surrounding soft tissues, which can be a concern during the reduction of nasal fractures.
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Postoperative Considerations:
- After manipulation and reduction of the nasal fragments, appropriate postoperative care is essential to monitor for complications such as swelling, infection, or malunion. Follow-up appointments may be necessary to assess healing and ensure that the nasal structure remains stable.
Inflammation is the respone of the body to an irritant.
Stages of Inflammation
1. General: Temperature Raised. In severe cases bacteremia or septicemia ,rigors may occur.
2. Local: classical signs of inflammation are due to hyperemia and inflammation exudate
i) Heat: inflammed area feels warmer than the surrounding tissues.
ii) Redness
iii) Tenderness: Due to pressure of exudate on the surrounding nerves If the exudate is under tension, e.g. a furuncle (boil) of the ear, pain is severe.
iv) swelling
v) Loss of function.
The termination of Inflammation
This may be by:1. Resolution 2. Suppuration 3. Ulceration 4. Ganangren s. Fibrosis
Management
i. Increase the patients resistance., Rest, Relief of pain by analgesics, Diet: High protein and high calorie diet with vitamins, Antibiotics, Prevent further contamination of wound.
Surgical measures
1. Excision: If possible as in appendicectomy.
2. Incision and drainage: If an abscess forms.
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