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Pathology - Membranous nephropathy Definition: A glomerulopathy characterized by widespread subepithelial immunological deposits within the glomeruli. Epidemiology: Rare occurrence. Etiology • The majority of cases are idiopathic, with the immune complexes believed to form in situ. The antigen in these instances remains unidentified. Some cases are due to other illnesses, such as malignancies, pharmaceuticals, infections, and systemic lupus erythematosus (SLE). In these instances, the immune complexes likely originate elsewhere and flow to the kidneys, where they are deposited in the glomeruli. Pathogenesis Immune complexes in the glomerulus compromise the normal filtration barrier, resulting in significant proteinuria. Presentation of nephrotic syndrome. Light microscopy • All glomeruli exhibit thickened, rigid capillary loops. • Silver staining reveals 'holes' in the glomerular basement membrane, indicative of immune deposits, and 'spikes' that signify the glomerular basement membrane's response to these deposits. • More advanced cases may additionally demonstrate tubulointerstitial fibrosis. Immunofluorescence Granular deposits of IgG and C3 are, by definition, diffusely present along the capillary loops. • The presence of deposits of IgA, IgM, and C1q necessitates consideration of membranous nephropathy secondary to systemic lupus erythematosus (SLE). Electron microscopy • Subepithelial electron-dense immune deposits are observed, accompanied by a variable response in the surrounding basement membrane. • Podocytes exhibit diffuse effacement of foot processes. Prognosis: Approximately one-third of patients have illness progression. 
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Pathology. - Minimal change disease Definition: A glomerulopathy with clinical symptoms of nephrotic syndrome and histologically normal glomeruli under light microscopy. Epidemiology • Uncommon. • Most commonly seen in children aged 2-6 years, but can also affect adults. The exact reason is unknown, however recent data shows it may be due to immunological malfunction. • Research has shown that minimal change disease (MCD) can occur after exposure to drugs, bee stings, or venom. Pathogenesis: • The podocyte is assumed to be the primary cell involved in MCD. • Normal podocyte activity is compromised, making the glomerular filtration barrier abnormally permeable to proteins. Presentation: • Nephrotic syndrome. Light microscopy shows typical glomeruli. immune fluorescence • No specific immune deposition is present. Electron microscopy reveals that podocyte foot processes are highly simplified and lack immune complexes. Prognosis: • MCD typically results in full recovery, especially in youngsters. Adults with steroid-resistant disease should be closely watched as they may have FSGS (b p. 148) that was not detected during biopsy due to its focused character.  Surgery - Incisions and Closures Body cavity incisions Incisions that allow access to each bodily cavity are referred to in general terms. • Laparotomy. An incision into the peritoneal cavity or retroperitoneal region. Laparotomies are classified based on their location in the abdomen, the tissues they traverse, or the individual who performed them • Thoracotomy. Accessing the chest cavity, usually in the pleural space or posterior mediastinum. A median sternotomy is a form of thoracotomy that allows access to the anterior and middle mediastinum . • Craniotomy. Accessing the skull's chambers. Incision closures Incisions are closed using certain basic ideas. • Fascial layers are ideal for supporting apposition and forming the primary abdominal closure. Heavy, non-permanent sutures are commonly used to close wounds. • When performing a craniotomy, bone flaws should be minimized to prevent movement. • Replace defects in fascial or bony structures with transposed or inserted tissues, such as skin, muscle, or polypropylene mesh. • Avoid large cavities and crevices between tissues to prevent infection-causing fluid accumulation.  Surgery - Surgical Instruments 'Sharps' • Scalps. There are two sizes of handles (4 and 6). Blade types and usage include no. 11 (stab incisions), no. 10 (most skin incisions), no. 15 (fine incisions), and no. 22 (adhesiolysis). • Scissors. It could be dissection or stitch cutting. Dissecting scissors can be straight or curved, such as Mayo, McIndoe, Metzenbaum, and Nelson's. Forceps • Non-toothed. DeBakey and Adson's forceps are fine, non-toothed instruments used to handle delicate tissues like arteries and bowels. This heavy, non-toothed tool is ideal for general handling, including specimens and sutures. • Toothed. Fine-toothed forceps, such as Gillies' and McIndoe's, are commonly used to handle skin and fascia, as well as to grip delicate tissues precisely. thick-toothed forceps, such as Lane's, are used to grip thick tissues like fascia and scars. • Ring-tipped and microforceps. Used for vascular anastomoses. Clips and Clamps • Artery clips, such as Spencer-Wells, Robert's (big), and Dunhill's, Mosquito (little), feature serrated jaws. Suitable for vascular clamps, tissue/suture holding. • Tissue clamps, including the Lahey clamp. Clamp with curved tip is commonly used for dissecting vessels. • • Doyen bowel clamp. Non-crushing atraumatic. Babcock/Duval clamp. This non-toothed, semi-atraumatic tissue-holding clamp is commonly employed for holding the bowel. • Use Lane's, Allis, or 'Littlewood' clamps. Tissue clamps with heavy teeth for traumatic use. Retractors • Self-retaining retractor: • Examples of large retractors include the Goligher retractor for abdominal incisions and the Finichetto retractor for thoracic procedures. • Travers (superficial) and Norfolk and Norwich (deeper) retractors are suitable for minor cutaneous and abdominal incisions. • • • Large handheld retractors, such as Deaver, Kelly, and Morris. Small (e.g. Langenbeck, Kilner/'Catspaw').  Clamps  Scapel  Forceps  Retractor Surgery – Scrubbing up Scrubbing up helps lessen the chance of infection from the surgeon to the patient. Using bactericidal soaps can lower the amount of organisms that can be cultured from skin swabs, but sterilizing the skin (especially sweat glands and hair follicles) is impossible. Surgical gloves can cause considerable bacterial development within 2 hours due to moisture and heat, even with contemporary cleaning solutions. Bactericidal soaps include chlorhexidine and povidone-iodine. Protocol When entering the theatre for the first time, introduce yourself to the senior scrub nurses. It is respectful and safe. It's important to understand the purpose and identity of those in the theatre. How To Scrub • Wet your hands and arms first. • Apply disinfecting soap and wash well. • Scrub under nails and excessively filthy areas with a sterile brush and disinfecting soap. Scrubbing too forcefully might cause irritation and have little bactericidal effect. • Use soap to thoroughly clean between fingers, back of hands, beneath fingernails, and base of thumbs. • Rinse well to eliminate soap and prevent skin irritation. • Rinse off, ensuring water runs off elbows. Dry your hands well before moving on to your arms. How to Gown and Glove : • Open the gown without touching the exterior 'face'. Do not put your hands through the cuffs. Pick up the right glove with your right hand still in the gown's cuff—palm side down, fingers pointing up towards your forearm. • Fold the other side of the glove's edge 'over' your right hand. • Insert your right hand into the glove. • Grab the left glove by the edge and pull it over the left hand's cuff. • Slide your left hand into the glove and adjust its position. Wearing eye protection and two pairs of gloves is a standard practice to prevent exposure to infectious pathogens. % Infection control strategies include hand hygiene and personal protective equipment (PPE).  Surgery - Sterilization, disinfection, and antiseptic Definitions • Sterilization involves removing all living germs, vegetative organisms, and spores. • Disinfection removes dividing vegetative germs. • Antisepsis reduces the danger of medical cross-infection from germs. Sterilization Heat: • Dry heat (e.g. incineration, blazing, red hot) is effective but rarely useful. Dry heat necessitates temperatures of 160°C for at least 60 minutes. • Moist heat, such as autoclave heating with pressurized steam at 121°C and 15lb/in2 for 15 minutes, is effective and useful for operating theaters. Irradiation involves gamma radiation. Effective with inorganic materials. Ultrafine membrane filters can disinfect air and fluids, although they are not commonly used in hospitals. Disinfection methods include using acids or alkalis, such as bleach. Effective for non-human contact applications. Examples of alcohols and phenols include ethyl alcohol for skin swabs, alcohol solutions for hand disinfection, carbolic chloroxylenols, and phenol (Clearsol®). • Oxidizers include povidone-iodine for skin disinfection and surgical washing, hydrogen peroxide (H2O2) for superficial wound cleansing, and aldehydes for surgical tools like endoscopes. • Cationic solutions, such as chlorhexidine, can be used for antiseptic wash. • Organic dyes, such as Proflavine. Antisepsis Antisepsis concepts include: • Remove gross contamination first with plain soap. • Use high-potency acid/alkali disinfectants on inert surfaces. • Apply less corrosive oxidizers to fragile inert materials. • Use weak alcohols and oxidizers to cleanse the skin.  Surgery - Positioning the Patient Getting the patient to the surgical table • The surgical team plays a role in ensuring patient safety during and after surgery. Ensure compliance with basic safety guidelines. • The anaesthetist is responsible for maintaining the patient's airway by coordinating all movements. • Avoid dislodging IV cannulae, epidural sites, or existing drains. • Use approved manual handling techniques, such as a 'Patslide' or comparable device, instead of lifting patients. • Take special precautions with prosthetic joints that may dislocate during relaxation, unstable fractures, Rheumatoid arthritis related instability, ulcers, or skin sores. Once in position. • Prevent diathermy exit point burns by ensuring no patient points come into contact with the operating table's metal surface. • Properly pad bony prominences and thin skin areas, such as the neck of the fibula in leg stirrups. • Ensure diathermy pads are properly applied and not impacted by skin preparations. • Provide adequate patient support, especially if the table is likely to shift, tilt, or rotate throughout the procedure (e.g., arm, thoracic, and abdominal supports for lateral positions, shoulder bolsters for head down positions). • When doing procedures that need access to the perineum, ensure sufficient pelvic support while exposing the perineum over the end of the operating table. • Plan the placement of ancillary equipment. For instance, where will video stacks be located? Is more than one energy source needed, and where will the generators be located? Is there access to mobile imaging equipment or on-table radiography? Position all equipment to offer the surgical team enough access to the patient.  Pathology - Prophylaxis: antibiotics and thromboprophylaxis. Preventive antibiotics • Prophylactic antibiotics lower the incidence of SSI and are often administered in a short term (1- 3 doses). • Antibiotic treatment for existing infections following surgery may last 5 days or more. • Prophylaxis is typically used to avoid infection of surgical wounds or to prevent the spread of organisms from colonized organs like the gut after opening. Thromboprophylaxis VTE is a widespread, preventable cause of mortality. Patients, like the general population, are 'at risk' of getting DVT. Evaluating the risk of venous thromboembolism To meet national VTE prophylaxis criteria, all patients must be screened for risk factors upon admission and again after 24 hours in the hospital. Risk is assessed based on: • Procedure considerations. Prolonged anaesthesia for lower limb or pelvic surgery. • Patient factors. Immobility, malignancy, aging, and inflammatory diseases Balanced against potential bleeding concerns. Active bleeding, stroke, invasive operations, and bleeding disorders (e.g. liver disease, thrombocytopenia, hereditary illnesses). Record the risks on the patient's drug chart or VTE documentation. Consider using mechanical (e.g., TEDS) or chemical (e.g., LMWH) thromboprophylaxis as per local guidelines. Patients who are fully anticoagulated do not require VTE prophylaxis. Extended VTE prophylaxis is required for some patient groups following surgery, such as lower limb joint replacement or pelvic surgery. Surgical and trauma patients are at risk of VTE if they meet any of the following criteria: • A surgical procedure lasting more than 90 minutes, or 60 minutes for pelvic or lower limb surgery. • Acute surgical admission for inflammatory or intra-abdominal conditions. • Expected reduced mobility. • One or more of the risk factors listed below. Treatment with mechanical instruments. • TEDS. Continuous direct compression helps reduce stasis in infrapopliteal veins. Not suited for those with PVD or cracked skin. • Pneumatic compression boots. Intermittent compression of the foot and lower leg veins promotes venous flow and reduces infrapopliteal vein stasis Risk factors for VTE include active or ongoing cancer therapy. • Over 60 years old (DVT tends to increase with age). • Admission for critical care. • Dehydration. • Known thrombophilias and polycythemia. • Obesity (BMI over 30 kg/m2). • Significant medical comorbidities, such as heart disease, diabetes, metabolic, endocrine, or respiratory pathologies, as well as acute infectious infections and inflammatory disorders. • A personal or first-degree relative with a history of VTE. • Use of hormone replacement therapy. • Use of estrogen-containing contraception. • Varicose veins with phlebitis. Women who are pregnant or have given birth within the last 6 weeks should seek guidance from specialists. Treatment: pharmaceutical • LMWH stimulates antithrombin III. • Given SC. Longer half-life than unfractionated heparin (UFH). • Examples are enoxaparin, dalteparin, and tinzaparin . • For renal failure, lower the dose or use UFH. Alternatively, titrate doses with anti-Xa monitoring. • UFH activates antithrombin III. • Given SC. Short half-life; reversible with protamine. • Fondaparinux inhibits factor Xa via antithrombin III . • Low risk of heparin-induced thrombocytopenia (HIT). There may be a lesser risk of bleeding compared to LMWH. Caution in cases of renal insufficiency. • Non-vitamin K antagonist oral anticoagulants (NOACs). • Advantages of daily PO dosage. • Examples: dabigatran, rivaroxaban, and apixaban. • Conventional clotting assays may not accurately evaluate the effect. • Most lack a direct antidote. Surgery - In-theater preparation Poor preparation and checking in the operating room can lead to risks for patients, such as wrong side surgery (e.g., removing a healthy kidney), incorrect site surgery (e.g., inguinal, not femoral, hernia repaired), allergic reactions to medication, insufficient vital materials (e.g., blood), insufficient equipment (e.g., image intensifier, specialist joint replacement jig), and retained swabs or instruments. Strict adherence to a checklist can reduce the probability of 'never occurrences' in high-risk industries, such as aviation. The WHO suggests a standardized checklist approach. WHO Checklist The WHO checklist is a customizable form with four essential checkpoints that can be tailored to specific organizations. Before the start of the operational list. • Ensure surgical, anaesthetic, and nursing teams are present and identifiable. • Confirm patient list, procedure order, and address any unique issues . • Verify that anesthetic equipment, medicine, and monitoring are in working order . • Confirm imaging and equipment requirements for the list. Before inducing anesthesia, ensure patient identity and permission are valid. Check the site and side markers, if applicable. Check that the anesthetic needs are correct and functional. Check for allergies and predicted blood loss. Before skin incision, ensure all team members are present and known. Check the procedure that will be conducted. Confirm any surgical, anesthetic, or nursing concerns. Confirm that critical imaging/equipment are available. Before leaving the theatre, ensure the correct name for the procedure conducted is known and recorded. • Verify the swab and instrument counts are accurate. Confirm that any surgical specimens were properly collected and labeled. Confirm any specific postoperative instructions.  Pathology - Prophylaxis: antibiotics and thromboprophylaxis. Preventive antibiotics • Prophylactic antibiotics lower the incidence of SSI and are often administered in a short term (1- 3 doses). • Antibiotic treatment for existing infections following surgery may last 5 days or more. • Prophylaxis is typically used to avoid infection of surgical wounds or to prevent the spread of organisms from colonized organs like the gut after opening. Thromboprophylaxis VTE is a widespread, preventable cause of mortality. Patients, like the general population, are 'at risk' of getting DVT. Evaluating the risk of venous thromboembolism To meet national VTE prophylaxis criteria, all patients must be screened for risk factors upon admission and again after 24 hours in the hospital. Risk is assessed based on: • Procedure considerations. Prolonged anaesthesia for lower limb or pelvic surgery. • Patient factors. Immobility, malignancy, aging, and inflammatory diseases Balanced against potential bleeding concerns. Active bleeding, stroke, invasive operations, and bleeding disorders (e.g. liver disease, thrombocytopenia, hereditary illnesses). Record the risks on the patient's drug chart or VTE documentation. Consider using mechanical (e.g., TEDS) or chemical (e.g., LMWH) thromboprophylaxis as per local guidelines. Patients who are fully anticoagulated do not require VTE prophylaxis. Extended VTE prophylaxis is required for some patient groups following surgery, such as lower limb joint replacement or pelvic surgery. Surgical and trauma patients are at risk of VTE if they meet any of the following criteria: • A surgical procedure lasting more than 90 minutes, or 60 minutes for pelvic or lower limb surgery. • Acute surgical admission for inflammatory or intra-abdominal conditions. • Expected reduced mobility. • One or more of the risk factors listed below. Treatment with mechanical instruments. • TEDS. Continuous direct compression helps reduce stasis in infrapopliteal veins. Not suited for those with PVD or cracked skin. • Pneumatic compression boots. Intermittent compression of the foot and lower leg veins promotes venous flow and reduces infrapopliteal vein stasis Risk factors for VTE include active or ongoing cancer therapy. • Over 60 years old (DVT tends to increase with age). • Admission for critical care. • Dehydration. • Known thrombophilias and polycythemia. • Obesity (BMI over 30 kg/m2). • Significant medical comorbidities, such as heart disease, diabetes, metabolic, endocrine, or respiratory pathologies, as well as acute infectious infections and inflammatory disorders. • A personal or first-degree relative with a history of VTE. • Use of hormone replacement therapy. • Use of estrogen-containing contraception. • Varicose veins with phlebitis. Women who are pregnant or have given birth within the last 6 weeks should seek guidance from specialists. Treatment: pharmaceutical • LMWH stimulates antithrombin III. • Given SC. Longer half-life than unfractionated heparin (UFH). • Examples are enoxaparin, dalteparin, and tinzaparin . • For renal failure, lower the dose or use UFH. Alternatively, titrate doses with anti-Xa monitoring. • UFH activates antithrombin III. • Given SC. Short half-life; reversible with protamine. • Fondaparinux inhibits factor Xa via antithrombin III . • Low risk of heparin-induced thrombocytopenia (HIT). There may be a lesser risk of bleeding compared to LMWH. Caution in cases of renal insufficiency. • Non-vitamin K antagonist oral anticoagulants (NOACs). • Advantages of daily PO dosage. • Examples: dabigatran, rivaroxaban, and apixaban. • Conventional clotting assays may not accurately evaluate the effect. • Most lack a direct antidote.  Surgery - Getting the patient to theatre Organizing and following a routine are crucial when preparing patients for surgical procedures. Inadequate preparedness can lead to serious implications for patients. Background papers Prepare the theatre or endoscopic list ahead of time to ensure accuracy. The list should include the patient's name, hospital number, location, surgery information, surgeon, and anesthesiologist. Patient paperwork • Ensure current medical notes are available for this admission, including a complete history and examination. • \tMonitor blood results for specific conditions, such as K+ in renal failure, clotting function in anticoagulated patients, and calcium (Ca2+) in parathyroidectomy patients. • Ensure patients have access to blood and blood products from the transfusion department. (Most hospitals have protocols for determining the appropriate quantity of units of blood.) • Ensure necessary imaging results are available. Ensure the consent form is completed and included in the medical notes. • Complete the medication chart. Patient preparation • Ensure the patient's procedure side/site is clearly indicated (if applicable). This should be done with the patient awake and validated by nursing staff. Check if the patient has been marked by any relevant professionals, such as a stoma care provider or a prosthetist for amputees. • Determine any necessary preparations, such as bowel preparation, ahead of time. Bowel preparation This device is used to empty the big bowel prior to surgery. Preparation options include a stimulant mechanical bowel preparation, such as sodium picosulfate, which should be given with plenty of drink at least 8 hours before surgery. Avoid any potential obstructions. • Use an osmotic mechanical bowel preparation, such as magnesium citrate or Klean Prep®, with 2-4 sachets diluted in water up to 8 hours before operation. Suitable for bowel preparation during colonic surgeries, including colonoscopy and CT colonography. • Stimulant left colon preparation, such as phosphate enema. Suitable for rectum/anus surgery or flexible sigmoidoscopy procedures. • Mechanical bowel preparation is now less common than it was previously. Bowel surgery may increase the risk of septic complications and has known adverse effects such as electrolyte imbalances, hypovolaemia in the elderly, and nausea and vomiting (especially with large-volume osmotic preparations). Getting The Patient to Theatre 97 Anaesthetic premedication. Reduces anxiety during anaesthesia preparation and reduces the need for anesthetic agents during induction. Benzodiazepines, such as diazepam (PO) or midazolam (5mg IV), are commonly utilized as preoperative agents. Hyoscine butylbromide is occasionally used to reduce upper aerodigestive tract secretions.  |
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