Surgery Flashcards
Causes of poor urine output post-surgery
Pre-renal:
- Hypovolaemia
- Hypotension
- Dehydration
Renal:
- Acute tubular necrosis
Post-renal:
- BPH
- Anticholinergics or adrenoreceptor agonists - often used in anaesthetics
- Pain
- Psychological inhibition
- Opiate analgesia
Which tests should be arranged for COPD patients prior to having surgery?
COPD pts are at higher risk of post-complications due to impaired resp function, so arrange:
- Lung function tests
- CXR
- ABG (if pt is known to retain CO2)
How long should Clopidogrel be stopped before surgery?
7 days
How long should Warfarin be stopped before surgery?
5 days - then switch them to a LMW heparin until the night before
How long should ACE inhibitors be stopped before surgery?
The day before
How long should the COCP be stopped before surgery?
4-6 wks and restarted at least 2 wks afterWH
How are steroids optimised peri-operatively?
Steroid demand increases during surgery, but pt on long-term steroids cannot do this due to suppressed renal function, thus:
- Switch oral steroids to 50-100mg IV hydrocortisone
- If there is any associated hypotension then add fludrocortisone
- For minor ops then oral pred can be restarted immediately post-op, but if major then pts may require IV hydrocortisone for up to 72 hrs
How are diabetic medications optimised peri-operatively?
- Metformin (OD) = take in the morning of the surgery
- DDP-4 inhibitors = take the morning of the surgery
- GLP-1 analogues = take the morning of the surgery
- SGLT-2 inhibitors = omit the day of the surgery due to DKA risk
Insulin rules:
- Schedule pt as early in the morning as possible to reduce the length of time their NBM
- If on long-acting insulin = continue but reduce by 20%
- Stop any other insulin and begin a sliding scale insulin infusion from when the pt is NBM
- Continue infusion until pt is able to eat post-op
- Switch to normal regime after first full meal
Absolute contraindications for laparoscopic surgery
- Obvious indication for open surgery
- Acute intestinal obstruction associated w/ a >4cm bowl dilation - can obscure the view
- Uncorrected coagulopathy = INR corrected to < 1.5
- Suspected intra-abdominal compartment syndrome
- Trauma w/ haemodynamic instability
- Clear indication of bowel injury
Relative contraindications for laparoscopic surgery
- ICU pts who are too ill to tolerate pneumoperitoneum
- Presence of anterior wall infection
- Laparoscopy w/in 4-6 wks
- Extensive adhesions
- Aorto-iliac aneurysmal disease due to risk of rupture
- Pregnancy
- Cardiopulmonary compromise
- Morbid obesity
Define Achalasia
A rare neuromuscular disorder characterised by the inability of the lower oesophageal sphincter to relax during swallowing and impaired peristalsis in the oesophagus - due to the degeneration of ganglion cells w/in the myenteric plexus
Achalasia features
- Dysphagia
- Regurgitation of undigested food
- Aspiration pneumonia
- Retrosternal chest pain/heartburn - often unresponsive to PPI’s
- WL
Achalasia investigations
- Endoscopy = may reveal a dilated oesophagus w/ residual food/fluid (primarily used to rule out other pathologies)
- Oesophageal manometry (gold standard) = demonstrates a high resting pressure and incomplete relaxation of the LOS
- Barium swallow = may show bird beak appearance in advanced cases
Achalasia management
Medical (for pts unsuitable for surgery):
- Botox injections
- CCBs or nitrates
Surgical:
- Oesophageal dilation
- Heller’s myotomy = cutting the LOS to loosen it
Define Acute mesenteric ischaemia
A life-threatening surgical emergency where there is abrupt onset of hypoperfusion to a portion of the small intestine - can either be occlusive (thrombus) or non-occlusive (low flow states e.g. HF, shock, major surgery) and most commonly affects the superior mesenteric artery
Acute mesenteric ischaemia features
- Sudden severe abdo pain w/ guarding
- N&V
- Signs of shock (hypotension, tachycardia, altered mental state)
- Metabolic acidosis on ABG
- Rectal bleeding in advanced ischaemia
Acute mesenteric ischaemia investigations
CT angiography
Acute mesenteric ischaemia management
- Resuscitation
- Anti-coagulation typically w/ IV heparin
- Surgery = embolectomy, arterial bypass or bowel resection if necrosis
- Intra-arterial vasodilators
- Thromboembolic therapy
- Supportive care
What is Grey-Turners sign?
Bruising along the flank indicating retroperitoneal bleeding in acute pancreatitis
What is Cullen’s sign?
Bruising around the peri-umbilical area associated w/ pancreatitis
Acute pancreatitis investigations
- FBC, U&E, LFTs
- Lipase and amylase
- USS
- MRCP to detect obstructive pancreatitis
- Endoscopic retrograde cholangiopancreatography (ERCP) - also therapeutic
- CT after resolution to detect pseudocysts or necrotising pancreatitis
How is Acute pancreatitis graded?
Using the modified Glasgow criteria to predict the severity - usually done on admission and 48hrs after admission, w/ a score of 3 or more +ve factors indicating a transfer to ITU
List the modified Glasgow criteria for pancreatitis
PANCREAS
PaO2 < 8kPa
Age > 55
Neutrophils - WBC >15
Calcium < 2
Renal function - urea >16
Enzymes - AST/ALT >200 or LDH >600
Albumin <32
Sugar - glucose >10
Acute pancreatitis management
- A-E
- Aggressive fluid resuscitation w/ crystalloids to maintain urine output > 30mL/hr
- Catheterisation
- Analgesia - strong opioids often needed
- Anti-emetics
Local complications of Acute pancreatitis
- Peripancreatic fluid collection = accumulation of fluid around the pancreas which may lead to infection, abscess formation or progress
- Pseudocyst = fluid-filled sac that lacks true epithelial lining, can rupture, become infected or compress adjacent structures
- Abscess
- Pancreatic necrosis = requires necrosectomy
- Haemorrhage
Systemic complications of Acute pancreatitis
- ARDS
- Hypovolaemia
- DM
- Sepsis
Anal fissure management
- Treat constipation
- Lodcaine cream/jelly
- Topical vasodilators to aid healing = e.g. nifedipine or nitro-glycerine
- 2nd line = topical diltiazem (CCB) or oral nifedipine
- Screen for IBD
Define Anal fistula
An abnormal connection between the epithelialized surface of the anal canal and perianal skin that is itself epithelialized - typically begins as an infection in the anal glands, which progresses to an anorectal abscess and then becomes a fistula
Anal fistula causes
- Crohn’s (most common)
- Malignancy
- Trauma
- TB
Anal fistula features
- Anal discharge - blood/purulent
- Anal discomfort or pain, exacerbated by sitting or defecation
- Open fistula on examination
Anal fistula management
- Analgesia
- Fistulotomy (opening of the track) to enable healing
- In advanced cases - Seton placement or advancement flap procedure may be used
What is Goodsall’s law?
A rule to predict the course of a perianal fistula:
- If the external opening is anterior to the transverse anal line, the fistula is straight and opens internally anterior to the transverse line
- If the external opening is posterior to the transverse anal line (or anterior but >3cm from the anus), the tract curves and opens at the 6 o’clock position internally
Define Angiodysplasia
A vascular malformation of the GI tract characterised by the formation of fragile, leaky vessels - often in the caecum and ascending colon
Angiodysplasia features
- Chronic, intermitent painless lower GI bleeding
- Can be fresh PR (if lesions in the colon) or melaena (if lesions in upper GI tract)
Angiodysplasia management
- Endoscopic treatments = thermal coagulation, argon plasma coagulation, endoscopic band ligation
- Angiographic embolization
- Octreotide or oestrogen-progesterone replacement
Anorectal abscess features
- Perianal pain and swelling
- Low-grade pyrexia
- Tachycardia
- Sepsis if severe
Anorectal abscess management
- Drainage in A&E under local
- Incision and drainage under GA = if degree of tissue dmg unknown, or in cases of deep abscess w/ sphincter involvement
- Abx if immunosuppressed pt or sepsis
Appendicitis aetiology
Develops due to obstruction w/in the appendix (from fibrous tissue, foreign body or hardened stool) - subsequent bacterial multiplication and infiltration of the appendix wall leads to tissue damage, pressure-induced necrosis and the potential for perforation
Appendicitis complications
- Local abscess formation
- Perforation
- Gangrene
- Post-op wound infection
- Peritonitis
Appendicitis management
- Prophylactic abx
- Laparoscopic appendicectomy is 1st line following abx
- Open appendicectomy + lavage indicated if evidence of perforation
- If there is -ve imaging = non-op management w/ IV fluids and abx
Define Ascending cholangitis
Severe, acute infection and inflammation of the biliary tree - due to obstruction (gallstones, strictures, malignancy) in the common bile duct, leading to bile stasis, bacterial overgrowth and ascending infection
Ascending cholangitis features
Charcot’s triad:
- RUQ pain
- Fever
- Jaundice
Ascending cholangitis investigations
- Bloods = deranged LFTs, elevated CRP and WCC
- Imaging = abdo USS 1st line looking for bile duct dilation - the use CT/MRCP/ERCP
Ascending cholangitis management
- Resuscitation
- Biliary drainage = via ERCP (+/- stent), Percutaneous transhepatic cholangiography (PTC), surgical drainage
Define Boerhaave syndrome
A full-thickness rupture of the oesophagus which occurs due to sudden increases in intraoesphageal pressure (usually repeated episodes of vomiting)
Boerhaave syndrome features
- Severe tearing chest pain that worsens on swallowing
- Minimal or no haematemesis
- Signs of shock
- Subcutaneous emphysema
- X-ray signs = pneumomediastinum, pleural effusions, pneumothorax
Boerhaave syndrome investigations
- CXR
- CT w/ contrast
- Avoid OGD as this may exacerbate the issue
Boerhaave syndrome management
- IV fluid resus
- IV abx to cover for potential mediastinitis
- Surgical correction of rupture
What is the rule of 9’s for burns?
Method for approximating the body SA affected by a burn:
- Head = 9%
- Torso (front) = 18%
- Torso (back) = 18%
- Whole arm = 9%
- Hand = 1%
- Whole leg = 9%
Classification of burns
- Superficial epidermal (1st degree) = affects just the epidermis
- Superficial partial (2nd degree) = affects the epidermis and upper layer of dermis
- Deep partial (2nd degree) = affects the epidermis, upper and deeper layers of the dermis
- Full thickness (3rd degree) = affects all layers of the skin to subcut tissue, can extend into muscle and bone (4th degree)
Burns features
- Superficial = painful, doesn’t blister or scar
- Partial thickness =Blisters and weeps, painful, increased risk of infection and scaring
- Full thickness = dry, insensate to light touch and pin prick, high risk of infection
Burns management
- A-E
- Pain management, usually w/ opiates
- IV fluids are required for children w/ burns >10% or BSA, and adults w/ burns >15% of BSA
- Fluid resus using the Parkland formula = %BSA burnt x weight x 4, half the fluid given over 8 hrs, the rest over 16
- Wound care
- Tetanus prophylaxis
- Refer to burns unit
- Skin graphs for full thickness burns
Burns complications
- Curling ulcer = stress-induced gastric ulcers due to psychological stress response
- Airway compromise from smoke inhalation
Cholangiocarcinoma risk factors
- Hx of gallstone or chronic cholecystitis
- Porcelain gallbladder
- Smoking
- Obesity
- PSC
- IBD
- Oestrogen exposure
- Occupational = pesticides, radiation, heavy metals and vinyl chloride
Cholangiocarcinoma features
- Abdo pain
- Jaundice
- Anorexia
- WL
- Courvoisier’s sign = painless, palpable gallbladder w/ jaundice is unlikely to be gallstone - more likely to be pancreatic or gallbladder cancer
Cholangiocarcinoma investigations
- Bloods
- USS 1st line
- CT
- ERCP for direct visualisation and biopsies
Define Cholecystitis
Acute/chronic inflammation of the gallbladder, usually due to gallstone obstruction - common organisms = E.coli (most common), klebsiella, enterococcus
Classification of Cholecystitis
- Acute = sudden onset inflammation, usually due to blockage of the cystic duct by gallstones, leading to bile build-up and inflammation
- Chronic = long-term inflammation due to repeated irritation by gallstones, overtime this causes thickening if the gallbladder wall and decrease in function - has milder symptoms than acute
- Calculous = cholecystitis caused by gallstone
- Acalculous = cholecystitis w/out gallstones - associated w/ critical illness, severe trauma or prolonged fasting which can lead to gallbladder stasis and ischaemia
Cholecystitis features
- RUQ/epigastric pain, which can radiate to the right shoulder
- Fever
- N&V
- +ve Murphy’s sign (pain on inspiration during palpation of the RUQ)
Cholecystitis management
Acute calculous:
- Conservative = in mild cases pt may be managed w/ bowel rest, fasting and IV fluids
- Abx
- Laparoscopic cholecystectomy - recommended to be during the same hospital admission or w/in a week
Chronic:
- Elective cholecystectomy
- Symptomatic management -= e.g. dietary modifications
Acalculous:
- Prompt cholecystectomy
Cholecystitis complications
- Empyema (gallbladder filled w/ pus)
- Gangrenous cholecystitis
- Perforation
- Abscess formation
- Bile duct obstruction
- Fibrosis
Define Chronic mesenteric ischaemia
A pathological condition presenting in elderly pts where there is insufficient blood flow to the intestines, usually due to a gradual blockage or narrowing of the mesenteric arteries
Chronic mesenteric ischaemia features
- Diffuse, colicky abdo pain, which worsens after eating
- Sig WL as pts avoid eating due to the pain
- Diarrhoea
- GI bleeding secondary to mucosal sloughing
- Abdo tenderness
- Epigastric bruit due to turbulent flow in the narrowed vessels
Chronic mesenteric ischaemia investigations
- ABG to check for raised lactate
- Duplex USS
- CT angiography (gold standard)
- Mesenteric angiography
Chronic mesenteric ischaemia management
- Risk factor management = stop smoking, diabetic control, statins
- Symptomatic relief = vasodilators
- Revascularization = percutaneous transluminal angioplasty
Chronic pancreatitis causes
- Primarily chronic alcoholism
- CF
- Pancreatic cancer
- Elevated triglycerides