Surgery fifth yr Flashcards
Summary of malignant hyperthermia?
condition often seen following administration of anaesthetic agents
characterised by hyperpyrexia and muscle rigidity
cause by excessive release of Ca2+ from the sarcoplasmic reticulum of skeletal muscle
associated with defects in a gene on chromosome 19. AD inheritance
Causative agents: halothane, suxamethonium, other drugs: antipsychotics (neuroleptic malignant syndrome)
Ix - CK raised, contracture tests with halothane and caffeine
Tx - dantrolene - prevents Ca2+ release from the sarcoplasmic reticulum
Causes of post-op pyrexia?
Early causes (0-5 days) include: Blood transfusion, Cellulitis, UTI, Physiological systemic inflammatory reaction (usually within a day following the operation), Pulmonary atelectasis - this if often listed but the evidence base to support this link is limited
Late causes (>5 days) include: VTE, Pneumonia, Wound infection, Anastomotic leak
4 W’s - wind, water, wound, what did we do?
Summary of postoperative ileus?
Due to reduced bowel peristalsis resulting in pseudo-obstruction.
Sx - abdominal distention/bloating, abdominal pain, nausea/vomiting, inability to pass flatus, inability to tolerate an oral diet
Deranged electrolytes can contribute to the development of postoperative ileus, so it is important to check potassium, magnesium and phosphate
Tx - NBM initially, may progress to small sips of clear fluid, NG tube if vomiting, IV fluids to maintain normovolaemia, additives to correct any electrolyte disturbances, TPN, occasionally required for prolonged/severe cases
Preparation for elective surgical cases?
Consider pre admission clinic to address medical issues.
Blood tests including FBC, U+E, LFTs, Clotting, Group and Save
Urine analysis
Pregnancy test
Sickle cell test
ECG/ Chest x-ray
The exact tests to be performed will depend upon the proposed procedure and patient fitness.
Risk factors for the development of deep vein thrombosis should be assessed and a plan for thromboprophylaxis formulated.
Patients having surgery may drink clear fluids until 2 hours before their operation and to fast from non-clear liquids/food for at least 6 hours before surgery.
Surgical preparation for diabetics?
Potential complications of poorly managed diabetes during surgery:
- undetected hypoglycaemia whilst a patient is under a general anaesthetic.
Diabetics have a higher risk of: increased risk of wound & respiratory infections, increased risk of post-operative acute kidney injury, increased length of hospital stay
patients treated with insulin who have good glycaemic control (HbA1c < 69 mmol/mol) and are undergoing minor procedures, can be managed during the operative period by adjustment of their usual insulin regimen
most patients taking only oral antidiabetic drugs may be managed by manipulating medication on the day of surgery, depending on the particular drug. There are some exceptions to this: if more than one meal is to be missed, patients with poor glycaemic control, risk of renal injury (e.g. low eGFR, contrast being used), in such cases a VRIII should be used
Specific preparation for surgery?
Thyroid surgery; vocal cord check.
Parathyroid surgery; consider methylene blue to identify gland.
Sentinel node biopsy; radioactive marker/ patent blue dye.
Surgery involving the thoracic duct; consider administration of cream.
Pheochromocytoma surgery; will need alpha and beta blockade.
Surgery for carcinoid tumours; will need covering with octreotide.
Colorectal cases; bowel preparation (especially left sided surgery)
Thyrotoxicosis; lugols iodine/ medical therapy.
Screening for AAA?
Single abdominal ultrasound for males aged 65.
<3 cm = normal = no further action
3-4.4cm - small aneursym - rescan 12m
4.5-5.4 - medium aneurysm - rescan 3m
> 5.5cm = large aneurysm = 2ww referral to vascular surgery
Management of AAA with low rupture risk?
asymptomatic, aortic diameter < 5.5cm (i.e. small and medium aneurysms)
abdominal US surveillance (on time-scales outlines above) and optimise cardiovascular risk factors (e.g. stop smoking)
Management of AAA with high rupture risk?
symptomatic, aortic diameter >=5.5cm or rapidly enlarging (>1cm/year)
Refer within 2wks to vascular surgery
EVAR or open surgery
EVAR - stent via femoral artery to stop blood collecting in artery
Complication of EVAR?
endo-leak, where the stent fails to exclude blood from the aneurysm, and usually presents without symptoms on routine follow-up
Cause of AAA?
result of the failure of elastic proteins within the extracellular matrix. Loss of intima with loss of elastic fibres from media
dilatation of all layers of arterial wall
degenerative disease
> 50 yrs normal, male = 1.7cm, female = 1.5cm
RFs for AAA?
Smoking
HTN
Syphilis
EDS
Marfans
Interpretation of ABPI?
> 1.2: may indicate calcified, stiff arteries. This may be seen with advanced age or PAD
1.0 - 1.2: normal
0.9 - 1.0: acceptable
< 0.9: likely PAD. Values < 0.5 indicate severe disease which should be referred urgently
Compression bandaging considered acceptable if ABPI >0.8
Summary of venous leg ulcers?
Venous HTN - secondary to chronic venous insufficiency (also calf pump dysfunction, neuromuscular disorders)
Due to capillary fibrin cuff or leucocyte sequestration
Features - oedema, brown pigmentation, lipodermatosclerosis, eczema
Above ankles. Painless
Deep venous insufficiency - related to previous DVT. Superficial venous insufficiency - varicose veins
Doppler - refluex, duplex US
Tx - management - 4 layer compression banding after excluding arterial disease or surgery. If fail to heal after 12 weeks or >10cm2, skin grafting may be needed
Summary of Marjolins ulcer?
SCC
Sites of chronic inflammation - burns, osteomyelitis after 10-20 years
Occur on lower limb
