NEET MDS Lessons
General Surgery
1 Cellulitis: a non-suppurative inflammation of subcutaneous tissue, extending along connective tissue planes and across intercellular spaces.
Spreading inflammation in the tissue planes is called cellulitis. There is wide spread swelling, redness and pain without definite localization.
Caused by Streptococcus pyogenes.. If general condition of the patient is undermined, as in diabetes, cellulitis spreads rapidly and leads to Septicemia (infection in the blood).Redness, itching and stiffness is present in the site of inoculation (where the bacteria enter the skin), local Gangrene (death of the tissue) may occur. The appearance of skin creases or wrinkles, indicates resolution (healing).
Treatment
1. Rest , Appropriate antibiotics.
Cellulitis of the neck: Is a complication of wounds tonsillitis or mastoiditis Ludwig’s angina is the term applied to sub-maxillary cellulitis. The two dangers of cervical cellulitis are:
1. Oedema of glottis - with possible asphyxia (respiratory obstructon )
2. Mediastinitis - In ludwig’s angina the floor of the mouth become oedematous. The tongue can be seen displaced, turned upwards by swelling and oedema. The patient is unable to close the mouth owing to oedema of the tongue and the floor of the mouth. This can also CCC when the tongue is bitten by a wasp.
Ludwig’s angina: Ludwig - characterized by a brawny (non pitting) swelling of the sub-mandibular region, corn with inflammatory oedema of the mouth. It is the combined cervical and intrabuccal signs that constitute the characteristic feature of the lesion. The cause of the condition is virulent, usually streptococcal infection of the cellular tissue surrounding the sub-mandibular salivary gland.
Clinical features
The swollen tongue is pushed towards the palate and forwards through the open mouth, while the cellulitis extends down the neck.
The most dangerous plane, is deep to the deep fascia.
Ludwig’s angina is an infection of closed fascial space and if .untreated, the inflammatory exudate often passes via, the tunnel occupied by stylohyhoid to the submucosa of glottis, in which event the patient is in immediate danger of death from oedema of the glottis.
Treatment
1. antibiotics on Early Diagnosis
2. In cases where the swelling, both cervical and intrabuccal, does not subside rapidly with such treatment, a curved incision, beneath the jaw is made and this decompresses the closed fascial space. The incision is deepened and after displacing the superficial lobe of the sub-mandibular salivary gland, the mylohyoid muscle are divided. This decompresses the closed fascjal space referred to. The wound is lightly sutured and drained. The operation can be conducted with greatest safety under local anaesthesia.
Bacteraemia and Septicemia
Bacteraemia and septicaemia means the organisms are present in the blood. Clinical features are those of severe infection and shock: , Pyrexia is intermittent , Rigors , Jaundice is due to liver damage, Acute renal failure may occur , Peripheral circulatory failure, lntravascular coagulation indicates a fatal outcome
causative focus found and treated surgically .g., Appendicetomy in perforated appendix
2. Blood culture taken
3. Broad spectrum antibiotic is given
4. Blood transfusion is given.
5. Injection hydrocortisone is given.
Pyaemia
Pyaemia is due to infected emboli circulating in blood stream. Pyaemia is characterized by: -
1. Rigors
2. Intermittent fever
3. Formation of abscess in vital organs like heart or brain.
Treatment
1. Is to prevent emboli reaching the blood stream
2. Broad spectrum antibiotic is given.
3. Abscess are incised and drained
If not treated portal pyaemia with multiple abscesses in liver occur, which is a dangerous condition.
Acute Abscess : An abscess a collection of pus.
Bacteria which cause pus formation is called pyogenic organisms. Bacteria reach the infected area by:
1. Direct route: eg. Penetrating wound
Local extension: From adjacent focus of infection
2 Lymphatics
4. Blood stream
Pyogenic membrane surrounds the abscess and is infiltration with (leukocytes and bacteria.
Pus: Pus contains dead leukocytes and bacteria. It reaches the surface of the body or is discharged into a hollow viscous.
Symptoms: patient feels ill., Throbbing pain is characteristic of suppuration. Pain becomes more severe in the dependent position. E.g. infected finger,
Classical signs
Temperature is elevated , Rigors, inflammation
Fluctuation: Present in the later stages, and reveals the presence of pus. Prevention
1. An abscess can sometimes be aborted by antibiotics in the early stage.,. Rest, Elevation of the affected part.
Treatment
Is incision and drainage of abscess
Hilton’s method of opening an abscess:
It is used where important anatomical structures like the blood vessels and nerves are preesnt, as in the neck, axilla and groin. The skin and superficial fascia is incised. A sinus forceps is thrust into the abscess cavity. The blades are opened and the pus is drained. A gloved finger is introduced and loculi are broken. A ribbon gauze is lightly packed and antibiotics are given. This is done under surface anaesthesia i.e., ethyl chloride spray.
Antibioma
If antibiotic is given the pus in the abscess frequently becomes sterile and a large brawny edematous swelling remains which takes many weeks to resolve.
Treatment: explore the mass with a wide-bore aspirating needle
Most antibiornas are due to late, inadequate, and ineffective antibiotics.
CANCRUM ORIS
Is an infective gangrene of cheek and lip.
may occur as a complication of kala azar, enteric fever and children with poor oral hygiene.
The lesion starts as an acute inflammatory patch on oral mucosa which is seen ulcerated.
The affected part of the cheek or the lip gradually becomes gangrenous.
Focal vascular thrombosis and sepesis occur.
When slough separates, a part of the cheek or lip sloughs out to form a buccal fistula with ugly deformity. The adjacent jaw may be infected too.
Various organisms are found - specially Fusiform bacillus and_Borrellia vincenti.
The foetid odour, gangrenous patch of cheek or lip, purulent discharge from the mouth, fever and toxaemia are the characteristic features. The patient is unable to open the mouth properly.
Treatment
1. Antibiotics, multivitamins and repeated mouth washes
2 Neostibamine in kala-azar. Sequestrectomy in chronic osteomyelitis of the mandible.
4. Plastic reconstruction of the lip or cheek for unsightly deformity undertaken.
CARBUNCLE
Is an infective gangrene of the subcutaneous tissue. It is due to staphylococcal aureus infection. It is uncommon before the age of 40. Males are the usual sufferers. Diabetes may be present. It often occurs on the nape of the neck.
Clinical features
Subcutaneous tissue becomes painful and indurated. Ove skin is red. Unless treated promptly, extension will occur and late softening. The skin gives way and thick pus and slough are discharged.
Usually, there is one central large slough, surrounded by smaller areas of necrosis. Infection extends widely and fresh openings appear
Treatment
1. Many carbuncles are aborted, if penicillin is used adequately in the early stage.
2. Local treatment consists of hygroscopic dressings being given ie. magsulph-glycerin dressing Later the carbuncle is excised with a cruciate incision.
3. If the gap is large and when the granulation tissue comes to the surface, skin grafting is done.
Cardiovascular Effects of Sevoflurane, Halothane, and Isoflurane
- Sevoflurane:
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Maintains cardiac index and heart rate effectively.
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Exhibits less hypotensive and negative inotropic effects compared to halothane.
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Cardiac output is greater than that observed with halothane.
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Recovery from sevoflurane anesthesia is smooth and comparable to isoflurane, with a shorter time to standing than halothane.
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- Halothane:
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Causes significant decreases in mean arterial pressure, ejection fraction, and cardiac index.
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Heart rate remains at baseline levels, but overall cardiovascular function is depressed.
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Recovery from halothane is less favorable compared to sevoflurane and isoflurane.
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- Isoflurane:
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Preserves cardiac index and ejection fraction better than halothane.
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Increases heart rate while having less suppression of mean arterial pressure compared to halothane.
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Cardiac output during isoflurane anesthesia is similar to that of sevoflurane, indicating a favorable cardiovascular profile.
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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.
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Contraindications for Oral Intubation
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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.
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Obstruction of the Oral Cavity:
- Conditions such as large tumors, severe swelling, or foreign bodies that obstruct the oral cavity can prevent successful intubation.
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Cervical Spine Instability:
- Patients with unstable cervical spine injuries may be at risk of further injury if neck extension is required for intubation.
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Severe Maxillofacial Deformities:
- Anatomical abnormalities that prevent proper visualization of the airway or access to the trachea.
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Inability to Open the Mouth:
- Conditions such as trismus (lockjaw) or severe oral infections that limit mouth opening can hinder intubation.
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Severe Coagulopathy:
- Patients with bleeding disorders may be at increased risk of bleeding during the procedure.
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Anticipated Difficult Airway:
- In cases where the airway is expected to be difficult to manage, alternative methods may be preferred.
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Contraindications for Tracheostomy
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Severe Coagulopathy:
- Patients with significant bleeding disorders may be at risk for excessive bleeding during the procedure.
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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.
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Anatomical Abnormalities:
- Significant anatomical variations or deformities in the neck that may complicate the procedure or increase the risk of injury to surrounding structures.
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Severe Respiratory Distress:
- In some cases, if a patient is in severe respiratory distress, immediate intubation may be prioritized over tracheostomy.
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Patient Refusal:
- If the patient is conscious and refuses the procedure, it should not be performed unless there is an immediate life-threatening situation.
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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.
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Unstable Hemodynamics:
- Patients with severe hemodynamic instability may not tolerate the procedure well, and alternative airway management strategies may be required.