Surgery 9 Flashcards
Which nerves may be damaged in a carotid endarterectomy?
Recurrent laryngeal nerve
Hypoglossal nerve
What is the difference between true leg length and apparent leg length?
True: ASIS to medial malleolus
Apparent: umbilicus to medial malleolus
NOTE: Galeazzi test checks whether the shortening is due to tibial or femoral shortening
List some causes of true leg shortening.
Fracture (e.g. NOF) Hip dislocation Growth disturbance (e.g. fracture, osteomyelitis) Surgery (e.g. THR) SUFE Perthes' disease
NOTE: apparent shortening maybe caused by scoliosis
List some causes of small bowel obstruction
Adhesions Hernia Paralytic ileus Faeces Foreign body Gallstone ileus Benign stricture Malignant stricture Drugs (e.g. TCA)
Outline the management of ACL rupture.
CONSERVATIVE: rest, physio to strengthen quads/hamstrings
SURGICAL: autograft repair (using semitendinosus, gracilis or patella tendon), tendon is threaded through heads of tibia and femur and held using screws
List some complications of open fractures.
Clostridium perfringens (gas gangrene) Hypovolaemic shock Neurovascular compromise Compartment syndrome Fat embolism
Which classification system is used for open fractures?
Gustillo-Anderson classification
1 - wound < 1 cm in length
2 - wound > 1 cm with minimal soft tissue damage
3 - extensive soft tissue damage
NOTE: compound fracture = open fracture
List some complications of total parenteral nutrition.
Line-related: pneumothorax, arrhythmia, line sepsis, thrombosis
Feed-related: villous atrophy, electrolyte disturbance (refeeding syndrome), hyperglycaemia, vitamin and mineral deficiencies
In general terms, how does the management of intracapsular fractures differ from extracapsular fractures?
INTRAcapsular: blood supply is likely to be interrupted so the head of the femur needs to be replaced (unless it is undisplaced)
EXTRAcapsular: blood supply less likely to be interrupted so it can be fixed (DHS) rather than replaced
Outline the post-operative VTE prophylaxis that is offered for patients undergoing hip and knee replacements.
THR: LMWH 10 days + aspirin 75/150 mg 28 days OR LMWH for 28 days OR Rivaroxaban
TKR: aspirin 75/150 mg for 14 days OR LMWH for 14 days OR Rivaroxaban
NOTE: for fragility fractures, continue LMWH or fondaparinux until no longer has significant reduced mobility
Which arteries supply blood to the head of the femur?
Retinacular vessels which are a branch of the medial and lateral circumflex femoral arteries which are branches of the profunda femoris
Profunda femoris branches off the femoral artery, which comes from the external iliac artery
IMPORTANT: medial circumflex is more important for NOF than lateral
List some differentials for monoarthritis.
Septic arthritis Crystal (gout, pseudogout) Trauma Haemarthrosis Reactive Psoriatic arthritis
List some indications for using a central line.
Central administration of medication (vasopressors, inotropes, chemotherapy)
TPN
Access for extra-corporeal circuit (haemodialysis)
Monitoring central venous pressure
NOTE: the tip should be seen at the cavo-atrial junction (2 vertebrae down from the carina). Insertion confirmed with CXR.
List some interventions that use Seldinger technique.
Central venous access
Arterial access (angiography)
Intra-abdominal/biliary/ureteric drainage
PEG insertion
List some indications for a chest drain.
Pneumothorax
Pleural effusion
Haemothorax
Post-surgical (cardiac, thoracic, oesophageal)
NOTE: in pneumothorax the tube should point upwards, in pleural effusion it should point downwards
List some indications for using surgical drains.
Drain potential space post-surgery
Removal of harmful fluid (blood, pus, bile)
Detection of bleeding or leakage (anastomosis)
List some complications associated with surgical drains.
Ascending infection Foreign body reaction (fibrosis/granulation) Migration Obstruction/kinking Fistulation
What CXR features would suggest that an NG tube is sited correctly?
Does it follow the path of the oesophagus?
Does it bisect the carina or bronchi?
Does it cross the diaphragm in the middle?
Is the tip clearly visible below the left hemidiaphragm?
What is the main indication for using a feeding NG tube?
Short or medium-term feeding (4-6 weeks) provided the patient has a functional GI tract (major surgery, malnutrition, coma, dysphagia)
Can also be used for administration of drugs/contrast in patients with an unsafe swallow
List some complications of NG tubes.
Aspiration pneumonia (due to incorrect position) Pneumothorax Malposition in GI tract Obstruction/knotting/kinking Reflux oesophagitis Gastritis Visceral perforation
List some indications for post-pyloric feeding.
Gastroparesis (DM, critical illness, neurological (MS, PD), scleroderma)
Gastric outlet obstruction (PUD, malignancy)
Recurrent aspiration
Pancreatitis (less stimulation of pancreas)
What are the two materials that urinary catheters can be made of?
Silicone (artificial)
Latex (natural - can cause allergic reaction)
NOTE: Coude/Tiemann catheters have a curved tip and they are used to get past enlarged prostates
List some indications for using a urinary catheter.
Urinary retention Measurement of urine output During abdominal/pelvic surgery Neurogenic bladder Immobility (e.g. stroke) End of life care Urinary incontinence
What are the three main types of scalpels?
10 - traditional blade with large cutting curve for skin incisions
11 - pointed apex for puncturing movements
15 - smaller cutting surface for more delicate control (for fine cutting)
Outline the general rules for using absorbable, non-absorbable and monofilament sutures.
Absorbable: deep or rapidly healing tissues (e.g. bowel/biliary/urinary anastomosis)
Non-Absorbable: permanent support and slower healing tissues (e.g. vascular, tendon, fascia)
Monofilament: superficial wounds (less tissue reaction)
Why is CO2 used to insufflate the abdomen in laparoscopic surgery?
It is inert, highly soluble and rapidly cleared by expiration
NOTE: techniques for laparoscopic trocar insertion include Veress needle and Hasson technique
What are the two forms of diathermy?
Monopolar: current flows between pen and electrode placed on the patient’s skin
Bipolar: both electrodes are mounted on forceps, used when tissue can be grabbed
NOTE: current can be continuous (pure cut) for cutting tissues or intermittent (coag) for coagulation of small vessels
What are some risks of using an oropharyngeal airway?
Vomiting
Aspiration
(If gag reflex present)
NOTE: nasopharyngeal airway is used in patients with reduced consciousness but an intact gag reflex (can cause ulceration and epistaxis and should be avoided in maxillofacial trauma)
List some indications for using a laryngeal mask airway.
Bridge to ET intubation during cardiac arrest
Elective or short surgery with low risk of aspiration
Rescue if failed intubation
NOTE: does NOT protect against gastric aspiration and should be avoided in patients with reduced chest compliance (risk of insufflating stomach and compressing chest)
What is a definitive airway?
Infraglottic
Secure (cuffed)
Prevents aspiration of gastric contents
Can deliver maximum concentrations of oxygen
List some indications for tracheostomy.
Weaning off mechanical ventilation
Severe maxillofacial trauma
List some indications for intubation.
Decreased consciousness and loss of airway reflexes
Failure to oxygenate (respiratory pathology, ARDS, pulmonary oedema)
Failure to ventilate (tiring patient in life-threatening asthma)
Failure to maintain upper airway patency (upper airway obstruction, angioedema, facial/upper airway trauma)
Outline the management options for hypertrophic and keloid scars.
Topical silicone gel sheets
Intralesional steroid and local anaesthetic injections
Antihistamines
Surgery: revision of scar
List some differentials for a groin lump.
Inguinal hernia Femoral hernia Saphena varix Undescended testicle Femoral artery aneurysm Lymph node Lipoma/sebaceous cyst
Which hand muscles are innervated by the median nerve?
Lateral two lumbricals
Opponens policis
Abductor policis brevis
Flexor policis brevis
LLOAF
List some causes of a positive Trendelenburg test.
Abductor muscle paralysis (e.g. due to superior gluteal nerve injury caused by hip fracture, hip dislocation and IM injections) Unstable joint (e.g. DDH, NOF) Insertion/origin of abductor muscles are approximated (e.g. severe coxa vara, dislocation)
NOTE: coxa vara is when the angle between the head and the shaft is < 120 degrees
What are the main stages of wound healing?
Haemostasis (vasospasm, platelet plug formation)
Inflammation (neutrophils migrate to wound and release growth factors)
Regeneration (fibroblasts produce collagen network)
Remodelling (collagen fibres remodelled)
Which routine bloods are one before any operation?
FBC U&E Group and Save Clotting Glucose
How should insulin-dependent diabetic patients be managed around an elective operation?
First on morning list and should be admitted the night before
Night before: reduce basal insulin by 1/3
Morning of: omit morning insulin, start IV variable rate insulin infusion (usually contains 50 U Actrapid)
Whilst NBM: 5% dextrose at 125 mL/hour, 2-hourly BM
Once eating/drinking: overlap insulin infusion with SC insulin
How should non-insulin dependent diabetic patients be managed around an elective operation?
Diet controlled: no extra action required
Metformin should be stopped on the day of surgery
Other hypoglycaemics (e.g. gliclazide) should be omited 24 hours before the operation
Place on variable rate insulin infusion with 5% dextrose (as for T1DM)
What are the risks of operating on a jaundiced patient?
Obstructive jaundice –> increased risk of renal failure
Coagulopathy
Increased infection risk (cholangitis)
How should anticoagulated patients with a low VTE risk be managed before an elective operation?
Stop warfarin 5 days pre-op (aim for INR < 1.5)
Restart warfarin the day after operation
How should anticoagulated patients with a high risk of VTE be managed before an elecive operation?
Stop warfarin 5 days pre-op and start LMWH Stop LMWH 12-18 hours pre-op Restart LMWH 6 hours post-op Restart warfarin the next day Stop LMWH when INR > 2
NOTE: high VTE risk includes valves and recurrent VTE
Outline the main principals of general anaesthesia.
Induction - e.g. propofol
Muscle relaxation - e.g. suxamethonium, rocuronium
Airway control - e.g. ET tube, LMA
Maintenance - e.g. halothane, enflurane
End of Anaesthesia - change inspired gas to 100% oxygen, reverse paralysis with neostigmine/atropine
List some complications of general anaesthesia.
Cardiorespiratory depression (propofol) Intubation injury (oropharyngeal) Loss of pain sensation (urinary retention, nerve palsies) Loss of muscle power (atelectasis) Malignant hyperthermia Anaphylaxis (colloid, antibiotics)
List some complications of inadequate analgesia for surgery.
Wound hypoperfusion (impaired wound healing) Reduced mobilisation (VTE, deconditioning) Reduced coughing (atelectasis, pneumonia)
List some causes of post-operative urinary retention.
Drugs (opioids, epidural/spinal anaesthesia, anticholinergics)
Pain
Psychogenic (hospital environment)
Describe the presentation of post-operative atelectasis.
Within 48 hours of operation
Mild pyrexia
Dyspnoea
Dull bases with reduced air entry
List some complications of breast surgery.
Arm lymphoedema
Seroma
Skin necrosis
List some causes of post-operative pyrexia.
EARLY: blood transfusion, physiological, atelectasis, infection
DELAYED: pneumonia, VTE, wound infection, anastomotic leak, collection
