Surgery Flashcards
(166 cards)
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