CST Interview - Clinical Scenarios Flashcards
Differential diagnosis for post-op (GI surgery) abdominal pain in unwell patient?
Anastamotic leak with peritonitis, septic shock, haemorrhagic shock, bowel perforation, ischaemic bowel, obstruction, wound infection, sepsis
Why can unwell patients with IBD be difficult to assess in terms of haemodynamics and clinical signs?
They tend to be immunosuppressed which can mask signs of peritonism. Also tend to be young with large physiological reserve
What is a stoma?
A therapeutic opening in the wall of a hollow viscus
How can you differentiate an ileostomy from a colostomy? 2 ways
An ileostomy has a spout vs colostomy flush to skin. Contents usually greenish, loose (small bowel content)
Types of ileostomy? 2
End ileostomy - single barrelled with 1 lumen
Loop ileostomy - double barrelled with proximal and distal lumen
What is the purpose of a loop ileostomy?
Divert enteral contents away from area of bowel that is e.g. healing or obstructed. Ex. j pouch in subtotal colectomy with ileorectal anastamosis
Which parts of the colon can be mobilised and therefore are suitable for loop colostomy formation?
Transverse and sigmoid
Differences between Crohns and UC? 3 differences
Crohns has full thickness skip lesions on histology, cobblestoning on endoscopy and can involve any part of GI tract. UC has continuous superficial ulceration usually in rectum and colon
Risk of multiple bowel resections for Crohns? Symptoms?
Short bowel syndrome - malabsorption of vitamins + minerals. Can be temporary. Diarrhoea + weight loss, malnutrition
At what level of small bowel loss does short bowel syndrome usually occur?
When there is <2m left of 6.1m short bowel left
Risk factors for anastamotic leaks? Split into 3 groups
Patient (smoker, diabetes, PVD, steroid use, malnutrition/anaemia). Pathology (IBD, collagen disorders, autoimmune disease). Procedural (tension across anastamosis, local infection, inadequate blood supply to cut ends, location low rectal more than right colon more than small bowel)
What are POSSUM and P-POSSUM? Stand for and use?
Validated scoring systems used to inform on risk of operative intervention by giving 30 day morbidity + mortality estimates. Stand for Physioloical and Operative Severity Score for the enUmeration of Mortality and Morbidity, (Portsmouth). 12 physiological and 6 operative variables.
Other than emergency, how can anastamotic leak presesnt post op?
Indolently with prolonged ileus, vague abdo pain, low grade temp + tachy.
Management of localised minor anastamotic leak?
NG tube + bowel rest, CT and/or water soluble enema. Antibiotics and drainage of collections
Cause of acidosis + deranged LFTs in patient post-op from liver resection?
Portal vein thrombosis
Management of basal atelectasis? Role of antibiotics?
Oxygen titrated to saturations, chest physiotherapy, coughing/deep breathing. Antibiotics only indicated if signs and symptoms present; not prophylactically although patients are at higher risk
General factors implicated in development of post-op atelectasis?
General anaesthesia (surfactant dysfunction, poor ventilation of basal alveoli), post-op immobility (poor ventilation)
Specific incision-related contributing factor to post-op atelectasis?
Large incisions e.g. subcostal discourage deep breathing
4 causes of post-op hyponatraemia?
Post-op SIADH, inappropriate crystalloid administration, drugs, post-op ileus
Causes of rising PT in post-op liver resection patient?
Vit K deficiency OR synthetic liver dysfunction e.g. post-hepatectomy liver failure or small-for-size syndrome
Stages of haemorrhagic shock in relation to blood loss and clinical sking/symptoms?
Stage 1 - less 15%, normal
Stage 2 - 15-30%, tachy, narrow pulse pressure
Stage 3 - 30-40%, tachy, hypotensive
Stage 4 - more 40% (2000ml), anuric, hypotensive
Management of hyperkalaemia?
Calcium gluconate 10mls 10%
Insulin dextrose 10 units 50mls 50%
Neb salbutamol
Serial measurements + cardiac monitoring
4 indications for dialysis in AKI?
Refractory hyperkalaemia
Refractory pulm oedema/overload
Severe metabolic acidosis
Uraemic encephalopathy/pericarditis
Difference between haemofiltration and haemodialysis?
Haemofiltration uses pressure of fluid across semipermeable membrane, hydrostatic pressure driving molecules into ultrafiltrate which is discarded + replaced. Haemodialysis used diffusion of molecules across membrane using dialysing fluid
2 scoring systems for AKI?
RIFLE (Risk, injury, failure, loss, end stage), AKIN (stage 1,2,3)
Definition of oliguria?
<400mls urine/24 hours
5 differentials for post-op orthopaedic leg swelling?
DVT, post-op haemarthrosis/oedema, infection, lymphoedema, fracture
Clinical features of DVT using Wells score?
Active cancer; paralysis/immobilisation of lower limb; bedridden for 3 days or 12 weeks major surgery; tenderness along distribution of deep venous system; entire leg swollen; calf swelling >3cm larger than other size; pitting oedema; collateral superficial veins; prev DVT; alternative less likely
If DVT likely on Wells?
D dimer, duplex US within 4 hours (or therapeutic LMWH + scan within 24 hours), scan repeated at 1 week if d dimer pos scan neg
If DVT unlikely on Wells
D dimer + scan if positive, rule out if negative
4 differentials for post op tonsillectomy pain + bleeding?
Post-tonsillectomy bleed secondary to lack of haemostasis
Not eating/drinking post op
Infection (less likely within 48 hours)
Alternative source e.g. haemoptysis/UGI bleed
How would you stop tonsillar bleeding in first instance?
Examine tonsillar fossa for fleeding points. Use local anaesthetic spray with adrenaline and try to cauterise bleeding vessels with silver nitrate stick
What if no clear bleeding vessel in tonsillar bleed?
Gargle hydrogen peroxide 3% diluted 1:4
What if a post op patient has had a small tonsillar bleed?
Admit for obs - can herald a larger bleed
If more than 48 hours post op (e.g. 5-9 days), what is the most likely cause of tonsillar bleed?
Secondary bleed - infection, also made worse by patient not E+D post op to clear slough
Management of paraphimosis?
Analgesia, attempt manual reduction, urology if unable
How to manually reduce paraphimosis?
Clean + drape, PPE. Glans and foreskin compressed to reduce swelling, thumbs on glans and fingers to reduce phimotic band
How does paraphimosis occur?
Prepuce is retracted proximal to corona of glans, causing constricting ring (phimotic band) which cuts off lymphatic and venous return. Swelling occurs and this worsens obstruction, worsening congestion and oedema.
Sequalae of paraphimosis?
Ischaemia necrosis and autoamputation
Regional local anaesthesia for paraphimosis?
Penile block to anaesthetise left and right dorsal penile nerves (10+2 o clock) or circumferential approach. DO NOT USE ADRENALINE as vasoconstrics
2 other non-op methods for reducing paraphimosis?
Bathe in concentrated dextrose (osmosis); Dundee technique to puncture prepuce and allow drainage, manually reduce
Differentials for UGI bleed?
Varices, Mallory Weiss tear, ulcer, cancer, vessel, gastritis/oesophagitis/duodenitis, drugs, bleeding disorders etc
What impact does PPI have on UGI bleed?
Reduces rebleeding risk and need for surgery, but not mortality in PUD
Risk stratification to predict rebleeding risk and mortality in UGI bleed? What does it involve?
Rockall - pre- and post-endoscopy factors incl age, pulse, BP, comorbidities, endoscopy diagnosis and signs of blood in GI tract
Indications for surgery in UGI bleed?
Severe despite transfusion of 6 (over 60) or 8 (under 60) units of blood, or if uncontrollable bleeding at endoscopy, rebleeding or high rockall scores
Where do varices most commonly occur?
Lower oesophagus, also greater curvature of stomach and rectum (and caput medusae)
What medication is used in variceal bleeding to reduce death risk?
IV terlipressin
Endoscopic management of varices?
If unable - sengstaken blakemore. If not, banding or sclerotherapy
2 first line methods of reducing risk of variceal rebleed?
Beta blockers, repeat endoscopic band ligation
For patients with UGI secondary to varices who are resistant to band therapy, what is another surgical option?
TIPSS (transjugular intrahepatic portosystemic shunt) - connects portal and hepatic veins in the liver
What is the rule of 3 for dilated bowel loops on AXR?
More than 3cm for small bowel, 6cm for large bowel, 9cm for caecum = distended
What is the utility of water soluble contrast in ?obstruction?
Mild therapeutic benefit, determining level of obstruction
What abnormal gas patterns indicate bowel perf on erect CXR and AXR?
Erect chest - air under diaphragm. AXR - Riglers sign = air both sides of bowel wall
Usual management for a sigmoid volvulus?
Pass rigid sigmoidoscope in lateral position to decompress, monitor for ischaemia/necrosis. Flatus tube
Usual patients who get sigmoid volvulus?
Elderly patients with chronic consiptation, poor mobility and comorbidities
Causes of large bowel obstruction?
Constipation, hernias, adhesions, tumours, volvulus. Less commonly intussusception (kids), gallstone ileus, Crohns, strictures (e.g. diverticular), foreign body
Causes of small bowel obstruction?
Adhesions, hernias, Meckels diverticulum, ileus, strictures, Ca
Management of suspected bowel obstruction?
ABCDE, NBM + NGT, IVT, analgesia/antiemetic, CT abdo/pelvis
3 types of nec fasc?
1 - polymicrobial. 2 - GAS +/- staph. 3 - clotridium perfrinigens (gas gangrene)
What may happen when area of nec fasc is incised?
Dishwater fluid, pus, necrotic tissue, positive finger sweep test
Intraop findings of nec fasc?
Necrotic tissue, fascial oedema, vessel thrombosis, dishwater fluid/pus
3 risk factors for developing nec fasc?
Immunocompromise, postsurgical, trauma e.g. IVDU/burns/lacs
Contraindications for skin grafting?
Fitness for surgery, local wound factors e.g. vascularity, oxygenation, presence of necrotic tissue, positive organism growth
3 groups of differentials for female with RIF pain?
Gen surg - appendix, Meckels diverticulitis, perforation. Gynae - ovarian torsion, ectopic, PID. Urological - UTI, renal stone
3 eponymous signs in appendicitis?
Rosvings, obturator, psoas sign
5 complications of appendicitis?
Chronic appendicitis, sepsis, abscess, perf, death
Why is appendicitis managed surgically first line? vs acute cholecystitis?
Appendix supplied by appendicular branch of ileocaecal artery which is an end artery. This can thrombose and become gangrenous with perforation. Gallbladder supplied by both cystic artery and right hepatic artery so has collateral.
Consent forms 1-4?
1 - adult consenting to treatment or procedure with capacity to do so.
2 - parent on behalf of child
3 - no conscious impairment e.g. under local
4 - lacks capacity - needs 2 senior clinicians, best interest, next of kin ideally
5 differentials for loin pain in elderly person?
AAA Pyelonephritis Renal colic Diverticulitis Gynae
RFs for AAA?
Vascular risk factors, CTDs, male
3 indications for AAA surgery?
Symptomatic (back or abdo pain), diameter over 5.5cm, growth over 0.5cm in 6 months
Aggressive fluids in ruptured AAA? Yes or no?
Permissive hypotension; not necessarily
Management for unruptured AAAs?
Conservative (lifestyle), medical (vasc RFs), surgical (open/endovascular)
Difference between true and false aneurysms?
True = dilatation of artery that involves all 3 layers of artery wall, false e.g. pseudoaneurysm is communication of blood between layers of artery wall and lumen without dilatation of all 3 layers
Screening for AAAs?
Males age 65 - USSS. Depending on size, discharge vs monitoring vs vascular surgeon
Where are most AAAs?
Infrarenal (95%)
5 differentials for acute lower limb pain?
DVT, acute limb ischaemia, fracture/MSK, compartment syndrome, gout
What are the 3 components of a normal doppler waveform?
Multiphasic, pulsatile and regular amplitude
Causes of acute limb ischaemia?
Acute thrombosis in situ (most common), embolic (AF, MI, heart valve, aneurysm, tumour, foreign body etc.) or other (trauma, popliteal aneurysm, dissection)
Differentiating between embolic and thromotic acute limb ischaemia?
Timeframe, multiple sites, source of embolis, prev claudication, artery palpation (hard in throm, soft and tender in embolic), bruits (present in thromb), collateral flow
Results of ABPI in relation to diagnosis?
Normal = over 0.7
Intermittent ischaemia 0.7-0.9
rest pain 0.3-0.7
critical ischaemia less than 0.3
What does FAST scan stand for?
Focused Assessment with Sonography in Trauma
Definition of massive haemothorax?
Drainage of over 1500mls when chest tube inserted or 200ml/hour for 2 hours
Where do you insert a chest tube?
5th ICS, just ant to mid axillary line (triangle of safety)
Bounds of triangle of safety?
Anterior border of latissimus dorsi posteriorly, lateral border of pectoralis major anteriorly, 5th ICSP inferiorly. Apex is axilla
Differentials for acute groin pain and swelling in elderly patient?
Hernia (incarcerated/obstructed), lymphadenopathy, saphenous varix, lipoma, femoral aneurysm, psoas abscess, AAA
Differentiating between small and large bowel loops on AXR?
Small - central, valvulae conniventes. Large - peripheral, haustra + taenia coli
Most common hernias?
Direct inguinal
In whom are indirect inguinal hernias most common?
Children
In whom are femoral hernias most common?
Older women
Definition and anatomical relations of a femoral hernia?
Abnormal protrusion of a peritoneal lined sac through the femoral canal, which runs medially to the femoral sheath and laterally to pubis. Contains fat and lymph node of Cloquet. Sheath contains NAV laterally
6 differentials for acute epigastric pain?
AAA, pancreatitis, cholecystitis, bowel obstruction/perf, PUD, DKA
3 major scoring systems for acute pancreatitis?
APACHE II, Glasgow, (modified), Ranson
When and why would you request a CT for ?pancreatitis?
Not within first 48-72 hours of symptom onset unless acute severe. Prognosticate/stratify risk of necrosis. Also if older patient ?carcinoma
5 complications of acute pancreatitis?
Chronic panc, necrosis (infection or sterile), ARDS, pseudocyst, haemorrhage
When do you score for pancreatitis?
Admission and 48 hours with Glasgow scoring
When do local complications of pancreatitis (necrosis, pseudocyst) generally occur?
Around 10-12 days of acute event
What investigation can be useful in assessing for cause of pancreatitis?
Abdo USS ?gallstones
Definitive treatment for gallstone pancreatitis and alternative if unfit for surgery?
Cholecystectomy; or ERCP + sphincterotomy
8 differentials for testicular swelling?
Torsion, epididymo-orchitis, varicocoele, hydrocoele, testicular tumour, hernia, epididymal cyst, mumps
Broadly different types of testicular tumour?
Seminoma vs non seminoma GCTs e.g. teratoma
4 RFs for testicular cancer?
FHx, Klinefelters, downs, cryptorchidism
Surgical approach to orchidectomy for cancer? Why?
Inguinal - vs scrotal - because allows cross clamping of spermatic cord to prevent dissemination of cancer cells along lymphatics, and allowing ligation of lymphatics as high as possible
What is the blood supply to the femoral head?
Trochanteric anastamosis formed by medial and lateral circumflex arteries and superior gluteal artery. Small supply from artery of ligamentum teres and medullary canal
Why is surgery required quickly in an intracapsular femur injury in under 65 patient?
Preserve blood supply to femoral head as hip replacement will likely need revision in later life
What is the difference between a closed, intracapsular femur injury in a 45 vs 85 year old?
Goal in 85 year old is to restore mobility with weight bearing as tolerated and minimize associated complications. In a 45 year old goal is to preserve femoral head (avoiding osteonecrosis) and achieve union, to avoid arthroplasty.
Surgery for closed intracapsular femur fracture in 45 y/o patient?
Anatomic reduction and stable internal fixation e.g. cannulated screws or DHS
Post-op management for young patient with hip fracture?
Non or partial weight bear for 6 weeks to facilitate healing
Guidelines for intracapsular fractures in elderly patients? Summary?
NICE/BOA - operate with aim to fully weight bear immediately post op, replacement arthroplasty if displaced intracapsular, THR sometimes, cemented hemi if not, orthogeri review
3 conditions for giving THR for elderly intracapsular hip fracture?
Walk independently before, not cognitively impaired, medically fit for anaesthetic
What is the alternative for intracapsular hip fractures to THR if patient doesnt fill criteria?
Cemented hemiarthroplasty
When would you use a DHS for hip fracture?
Extracapsular, pertrochanteric OR young intracapsular
When would you use an IM nail for hip fracture?
Extracapsular, subtrochanteric
How long do THRs typically last prior to loosening?
15-20 years
