Surgery Flashcards
Name a classification system used to determine ease of intubation
Mallampati classification
Name a classification system used to calculate morbidity and mortality in general surgical patients
POSSUM score
What drugs are stopped before surgery?
CHOW:
- Clopidogrel (7 days)
- Aspirin/dipyridamole can be continued
- Hypoglycaemics (day of surgery)
- OCP/HRT (4 weeks) due to DVT risk
- Warfarin (5 days) due to bleeding risk
- Check INR day before surgery
What drugs should be altered before surgery?
- SC insulin - switched to IV variable rate infusion
- Long term steroids (continued due to Addisonian crisis risk)
What drugs should be started before surgery?
- LMWH (dalteparin) 5000 units if general surgery
- 28 days post-op
- Antibiotics prophylaxis if appropriate
- TED stockings (not vascular surgery)
How is diabetes handled before surgery?
- Commence sliding scale night before
- Stop metformin morning of surgery
- First on list to allow best management of blood glucose while NBM
- 5% dextrose 125 ml/hr while NBM
How is an AAA defined?
Irreversible dilatation of the abdominal Aorta >3cm
- Infrarenal 95%
True = contains all 3 layers of artery wall
False = Only lined by surrounding connective tissue/adventitia
Name some risk factors for developing AAA
- Smoking
- Hypertension
- Hyperlipidaemia
- Family history
- Male
- Age > 65
- Connective tissue disease
What are the clinical features of AAA?
Mainly asymptomatic
- Abdominal / back / loin pain
- Distal embolisation - limb ischaemia
- Pulsatile mass in abdomen (above umbilicus)
What is the screening programme for AAA?
NAAASP = abdominal US for all men aged 65
How is AAA managed?
- AAA < 5.5cm monitored via duplex US
- 3.0-4.4cm = yearly
- 5.0-5.4 = 3 monthly
- Reduce CVS risk factors (smoking, BP/DM control, weight loss, statin, aspirin)
- Surgery if > 5.5cm, explanding >1cm/year or symptomatic
- Open repair = inlay synthetic graft
- Endovascular repair (EVAR) = stent via femoral arteries
Name some complications of AAA
- Rupture
- Retroperitoneal leak
- Embolisation
- Aortoduodenal fistula
What are the clinical features of a ruptured AAA?
- Severe/sudden epigastric/back/loin pain
- Transient hypotension
- Sudden collapse/syncope
- Vomiting
- Pulsatile abdominal mass
- Haemodynamic instability
- Sweating
- Grey-Turner’s sign
How is ruptured AAA managed?
- 2 large bore cannulae - fluids/O neg
- Keep BP < 90 mmHg (permissive hypotension)
- Activate major haemorrhage protocol
- High flow O2
- Bloods - FBC, U&E, clotting, crossmatch 6 units
- Analgesia (morphine 5-10mg)
- Contact vascular surgeon
- If stable - CT with contrast
What is an Aortic dissection?
Tear to intimal layer creates false lumen between layers of the wall
- Acute < 14 days
- Chronic > 14 days
- Anterograde towards iliacs
- Retrograde towards Aortic valve
Name a classification of thoracic Aortic dissection
DeBakey classification:
- I = originates in ascending Aorta and propagates to at least Aortic arch
- II = ascending Aorta only
- III = originates distally to left subclavian artery
- IIIa = extends to diaphragm
- IIIb = extends beyond diaphragm
Name some risk factors for Aortic dissection
- Hypertension
- Male
- Atherosclerosis
- Caucasian
- CTD
- Bicuspid Aortic valve
What are the clinical features of Aortic dissection?
- Tearing / stabbing chest pain
- Radiates to back
- Tachycardia
- Hypotension
- New Aortic regurgitation murmur
- End-organ hypoperfusion
How is Aortic dissection investigated?
- Bloods - FBC, U&E, LFTs, troponin, coagulation, crossmatch 6 units
- ABG
- ECG
- CT angiogram
- Transoesophageal Echo
How is Aortic dissection managed?
- High flow O2
- Catheterise and fluid balance
- 2 large bore cannulae and fluid resuscitation
- permissive hypotension (100mmHg)
- DeBakey I+II = surgery (removal of ascending Aorta and replacement with synthetic graft
- Debakey III = manage hypertension with beta blockers (or CCB)
- Surgery if visceral/limb ischaemia, refractor pain or uncontrolled hypertension
- Endovascular with stent graft
- Lifelong antihypertensives and surveillance
What are the complications of Aortic dissection?
- Rupture
- Aortic regurgitation
- Stroke
- MI
- Cardiac tamponade
How is carotid artery disease investigated?
- Urgent CT - ischaemic or haemorrhagic
- Bloods - FBC, U&E, clotting, lipid profile, glucose
- ECG
- CXR
- Colour duplex scan (degree of stenosis)
- CT angiography
What is the acute management of carotid artery disease?
- High flow oxygen
- Swallow screen assessment
- Ischaemic = IV alteplase (tPA) within 4.5 hours of symptom onset
- 300mg aspirin 14 days
- Haemorrhagic = clot evacuation
What is the long term management of carotid artery disease?
- CVS risk factor reduction - smoking, BP/DM control
- Anti-platelet therapy - aspirin, dipyridamole
- Statin (simvastatin 40mg daily)
- Carotid endarterectomy if symptomatic > 70% stenosis of ICA or > 50% stenosis with recent TIA
- Within 2 weeks
- Removes atheroma and damaged intima with temporary bypass shunt
Name some risks of carotid endarterectomy
- Stroke
- Hypoglossal nerve damage = weak tongue
- Glossopharyngeal nerve damage = swallowing dysfunction
- Vagus nerve damage
- MI
- Bleeding
- Infection
What are varicose veins? What veins do they usually affect/
Tortuous, dilated segments of vein associated with valvular incompetence
- Majority long saphenous vein (ant. medial malleolus to femoral vein)
- Minority short saphenous vein (post. lateral malleolus to popliteal vein)
Name some risk factors for developing varicose veins
- Prolonged standing
- Obesity
- Pregnancy
- Family history
What are the clinical features of varicose veins?
- Cosmetic - skin discolouration, visible veins
- Pain
- Aching
- Swelling/oedema
- Thrombophlebitis
- Ulcers (medial malleolus)
- Lipodermatosclerosis = tapering of legs above ankle (upside down champagne bottle)
- Atrophie blanche
- Saphena varix = dilatation of saphenous vein at sapheno-femoral junction
How are varicose veins investigated?
- Trendelenberg test = patient supine, elevate leg to allow veins to empty, apply tourniquet in high thigh and ask patient to stand
- Release tourniquet - if rapidly fill up then incompetent valve is SFJ
- Doppler (exclude arterial pathology)
- Colour duplex US
How are varicose veins managed?
- Education - avoid prolonged standing, weight loss, exercise
- Compression stockings if interventional treatment inappropriate
- CI in arterial ulcers
- If venous ulcer = four-layer compression bandaging
- Surgery
- Vein ligation, stripping and avulsion
- Foam scleropathy = inject sclerosing agent into vein to close it off
- Thermal ablation = heating vein from inside to close it off
What are the indications for surgery in varicose veins?
- Symptomatic
- Skin changes
- Superficial vein thrombosis
- Venous ulcer
Name some complications of varicose vein surgery
- Bruising
- Recurrence (50%)
- Haemorrhage
- Wound infection
- DVT
- Thrombophlebitis
- Nerve damage - saphenous/sural
What is intermittent claudication?
Muscular pain on exercise associated with early-stage peripheral artery disease
Name some risk factors for intermittent claudication
- Hypertension
- Hyperlipidaemia
- Diabetes
- Smoking
- Family history
- Obesity
- Sedentary lifestyle
- Diet
- Male
What are the clinical features of intermittent claudication?
- Pain with exercise
- Relieved by rest
- Cyanosis
- Pallor
- Weak/absent distal pulses
- Atrophic changes
- Dec hair
- Shiny skin
How is intermittent claudication investigated?
- Buerger’s test = patient supine, elevate legs to 45 degrees for 1-2 mins
- Pallor = ischaemia (peripheral arterial pressure is inadequate to overcome gravity)
- Hang legs over bed - blue to red
- Buerger’s angle
- ABPI (Ankle-brachial pressure index) systolic in leg / highest systolic in either arm (<1 = abnormal)
- BP
- Serum glucose, cholesterol
- Angiography
How is intermittent claudication managed?
- Risk factor modification - smoking, exercise, statins, BP control, DM control, antiplatelet
- Pharmacological (improve blood flow/circulation)
- ACE inhibitor
- Beta blockers
- Naftidrofuryl (vasodilator)
- Pentoxifylline (xanthine)
- Surgery
- Angioplasty (Aorto-iliac or superficial femoral)
- Common femoral endarterectomy
- Graft (Aortobifemoral)
- Bypass (popliteal)
What is acute limb ischaemia?
Sudden decrease in the limb perfusion that threatens the viability of the limb
Name some causes of acute limb ischaemia
- Thrombosis - artheroma in artery ruptures and a thrombus forms on the fibrous cap
- Dehydration
- Hypertension
- Malignancy
- Polycythaemia
- Emboli = thrombus travels distally to occlude the artery
- AF
- MI
- Prosthetic heart valves
- AAA
- Trauma (compartment syndrome)
- Aortic dissection
- Peripheral aneurysm
What are the clinical features of acute limb ischaemia?
6 Ps:
- Pain
- Pallor
- Parasthesia
- Pulselessness
- Paralysis
- Perishingly cold
Irreversible - mottled skin, petechial haemorrhages, hard muscles
How is acute limb ischaemia investigated?
- Bloods - FBC, U&E, troponin, clotting, glucose, G&S, lactate, thrombophilia screen
- ECG (dysrhythmias)
- CXR
- Doppler ultrasound
- CT angiography
How is acute limb ischaemia managed?
Irreversible ischaemia within 6 hours
- 100% O2
- Fluids
- Analgesia (5-10mg morphine IM + anti-emetic)
- Heparin IV bolus (5000 IU unfractionated) + start infusion
- If embolic - embolectomy (Fogarty catheter), local intra-arterial thrombolysis, bypass surgery
- If thrombotic - local intra-arterial thrombolysis, angioplasty, bypass surgery
What are the complications of reperfusing after acute limb ischaemia?
Reperfusion injury (release from damaged muscle cells):
- Hyperkalaemia
- Acidosis
- Rhabdomyolosis
- AKI
What is chronic limb ischaemia?
Peripheral arterial disease that results in symptomatic reduced blood supply to the limbs
- Commonly lower limbs
Name some clinical features of chronic limb ischaemia
- Intermittent claudication
- Ulcers
- Weak/absent pulses
- Gangrene
- Pallor
- Cold limbs
- Skin changes - atrophic, hair loss, thickened nails
Name a chronic limb ischaemia classification system
Fontaine classification:
I: asymptomatic
II: intermittent claudication
III: ischaemic rest pain
IV: ulceration and/or gangrene
What is the criteria for critical limb ischaemia?
- Ischaemic rest pain for > 2 weeks
- Presence of ischaemic lesions or gangrene
- ABPI < 0.5
What is Leriche Syndrome?
Peripheral arterial disease affecting the aortic bifurcation
- Buttock/thigh pain
- Erectile dysfunction
How is chronic limb ischaemia investigated?
- ABPI (normal > 0.9, severe < 0.5)
- Value > 1,2 could represent calcification/hardening due to diabetes
- Buerger’s test (angle when limb goes pale)
- Doppler US - assess severity and anatomical location
- CT/MR angiography
- CVS risk assessment - BP, BM, cholesterol, ECG