Surgery - pre/post op

Question 1

What are some risk factors for post op nausea?

Answer 1

female, hx of motion sickness, non smoker, post op opiates, young age, volatile anaesthetics

Question 2

How would you manage post op nausea?

Answer 2

• Prophylaxis
  
  • Prophylactic antiemetic therapy (ondansetron, cyclizine)
  • 8mg dexamethasone at induction of anaesthesia
  • Reduce opiates, reduce volatile gases, avoid spinal anaesthetics
• Conservative
  
  • Fluids, analgesia, NG to aid gastric decompression
• Pharmaceuticals
  
  • Impaired gastric emptying or gastric stasis = metoclopramide or domperidone (unless bowel obstruction!!!!)
    
    • Otherwise hyoscine to reduce secretions in bowel obstruction
  • Metabolic or electrolyte imbalances etc = Metoclopramide
  • Opioid induced = ondansetron or cyclizine

Question 3

What is enteral feeding and what are the options?

Answer 3

Via GI tract

• Via mouth
• NG tube
• Percutaneous endoscopic gastrostomy (tube from skin to stomach)

Question 4

What if the GI tract use isn’t possible for feeding?

Answer 4

Total parenteral Nutrition

• an IV infusion of carbs/fats/proteins/vits/minerals solution
• via central line as it is irritant to veins = causes thrombophlebitis

Question 5

How long would you be off fluids and food pre op?

Why is it necessary?

Answer 5

• 6 hours no food
• 2 hours no clear fluids
• Important as it empties stomach, reduces risk of reflux and aspiration (Pneumonitits)

Question 6

What would you do about anticoagulants, contraception, corticosteroids, diabetic meds, insulin pre-op?

Answer 6

• Stop anticoagulants
  
  • Rapidly reverse warfarin with vit k in acute scenarios
  • Treatment dose LMWH or Unfractionated heparin infusion can bridge for stopping warfarin for high risk patients surgeries, and stopped shortly before surgery
  • DOACs stopped 24-72 hours before surgery
• Oestrogen containing contraception is stopped 4 weeks before (vte risk)
• Long term corticosteroids need to be altered or increased
• Diabetic meds
  
  • Sulfonylureas omitted until eating and drinking post op
  • Long acting insulin should be continued at 80% dose
  • Stop short acting insulin until eating/drinking again
  • Have a variable rate infusion along side a glucose, NaCL and K+ infusion (sliding scale)

Question 7

How would you do vte prophylaxis?

Answer 7

• VTE prophylaxis
  
  • LMWH like enoxaparin or DOAC (apixaban, rivaroxaban)
  • Intermittent pneumatic compression (flowtrons)
  • Anti-embolic compression stockings
    *

Question 8

What is it called when you need to quickly put some one under GA without being able to fast them etc

Answer 8

• Rapid sequence intubation is used for emergency situs (gaining airway control asap where pt is not fasted, etc)
  
  • Reduce risk of aspiration by positioning bed upright and applying cricoid pressure

Question 9

What is the triad of anaesthesia?

Answer 9

Hypnosis, Muscle relaxation, Analgesia

Question 10

How would you do “Hypnosis”

Answer 10

• Hypnosis = to make patient unconsicous
  
  • IV = propofol or ketamine or thiopental sodium (rare) or etomidate (rare)
  • Inhaled = sevoflurane, desflurane (bad for environment), isoflurane (rare), nitrous oxide (kids)
  • Typically IV is used to induce and inhaled are used to maintain, as inhaled needs time to diffuse across lung tissue into blood so takes longer to reach an effective conc.
  • Total IV anaesthesia is just IV for induction and maintenance (commonly propofol) and results in nicer recovery

Question 11

How would you do “muscle relaxation” (2 types)

Answer 11

• Muscle relaxation
  
  • Depolarising eg suxamethonium
  • Non-depolarising eg rocuronium and atracurium
  • Cholinesterase inhibitors (neostigmine) reverse these
  • Sugammadex reverses non-depolarising muscle relaxants

Question 12

What is commonly used for analgesia?

Answer 12

alfentanil, fentanyl, remifentanil, morphine

give antiemetics too

Question 13

What is emergence?

Answer 13

• muscle relaxants need to have worn off before you wake them!!!
• Use nerve stimulator (ulnar nerve at wrist to see thumb movement)
  
  • do it in a train of 4 stimulation to see if it has worn off
• Otherwise use drugs like sugammadex

Question 14

What is malignant hyperthermia

Answer 14

• A risk with volatile anaesthetics (isoflurane, sevoflurane, desflurane) and suxamethonium
• Also a risk with certain genetic mutations (autosomal dominant)
• Presentation
  
  • Hyperthermia (high body temp), high co2 exhalation, tachycardia, muscle rigidity, acidosis, hyperK
• Manage with dantrolene

Question 15

How would you measure pain?

Answer 15

Visual analogue scale and numerical rating scale

Question 16

Talk through the WHO analgesia ladder

and some SE

Answer 16

• WHO Pain Ladder
  
  • Simple analgesics = paracetamol, nsaids (ibuprofen, diclofenac)
    
    • Nsaids inhibit prostaglandins synthesis, reducing inflammatory response causing the pain
    • Nsaids SE =
      
      • Interactions with warfarin
      • Gastric ulcer
      • Renal impairment
      • Asthma sensitivity
      • Bleeding risk
  • Weak opiates = codeine, tramadol
    
    • Always prescribe concurrent paracetamol to reduce their requirement for regular opioids
    • Avoid weak+strong opioids as they competitively inhibit the same receptor
  • Strong opiates = morphine, oxycodone, fentanyl
    
    • Se = constipation, nausea, sedation, confusion, resp depression
    • Prescribe laxatives and anti-emetics
    • Oxycodone or fentanyl is best for renal impairment

Question 17

What could you use for specific pain relief? what are some pros and cons

Answer 17

• Patient controlled analgesia = IV pumps that deliver a bolus of analgesia when a button is pressed
  
  • Pros
    
    • as there is a period of unresponsiveness between presses, overdose is a low risk
    • Accurately records how much opioid is used so easily converted to regular dose if needed
  • Cons
    
    • Prevents patient mobilising
    • Inappropriate for poor manual dexterity or severe learning difficulties

Question 18

What would you do for neuropathic pain?

Answer 18

• Non pharm = CBT, capsaicin cream, Transcutaneous electrical nerve stimulation
• Pharm = gabapentin, amitriptyline, pregabalin, duloxetine

Question 19

What scoring systems are used in ICU for predicting mortality?

Answer 19

• APACHE
• SAPS
• MPM

Question 20

What are some complications associated with ICU use of ventilators and catheters?

Answer 20

• Ventilator associated lung injury
  
  • Volutrauma (overinflation of alveoli) + barotrauma (damage from pressure changes) = inflammation
  • Results in fibrosis, reduced lung function, recurrent infections
• Ventilator associated pneumonia
  
  • Position bed at 30 degrees reduces risk of aspiration and infection
  • Also do oral care and mouth cleaning to reduce risk
• Catheter related bloodstream infections (eg central venous catheters)
  
  • Use antibiotic impregnated or silver impregnated catheters
  • Reduce time they are in
• Catheter associated urinary tract infections

Question 21

What is stress related mucosal disease? (ICU)

Answer 21

• Damage to stomach mucosa occurs due to impaired blood flow
• This can result in life threatening upper gi bleed
• Give PPIs or H2 receptor antagonists to reduce risk
• Start NG early for those who cannot eat normally, even if just small trophic feeds (insufficient to meet nutritional requirements but good for gi benefits)

Question 22

What is critical illness myopathy and critical illness neuropathy? (ICU)

Answer 22

• Critical illness myopathy
  
  • Muscle wasting and weakness during treatment
  • Caused by muscle relaxants and corticosteroids
  • Makes it difficult to wean off ventilation
  • Reduced exercise capacity and reduced qol long term
• Critical illness neuropathy
  
  • Degeneration of sensory and motor nerve axons during treatment
  • Results in symmetrical weakness, decreased tone, reduced reflexes
  • Do glycaemic control!!

Question 23

What would you be thinking about the causes of post op pyrexia?

Answer 23

• 0-5 days post op, consider body’s physiological response to surgery
• 1-2 days = Wind = resp infection or physiological response
• 3-5 days = Water = resp or urinary tract infection
• 4-6 days = Walk = DVT, PE
• 5-7 days = Wound = surgical site infection, abscess, collection
• 7+ = wonder about drugs = transfusion reaction, antibiotics/anaesthetic agents reaction
• Always check iv lines or central lines for infection
• Specific reasons eg. in a bowel resection, check for anastomotic leaks

Question 24

What are some basic antibiotics regimes for infections?

Answer 24

• Low threshold for sepsis!!! Don’t be afraid to ask for early senior review
• Empirical antibiotics pending cultures as per hospital guidance
  
  • LRTI = co-amoxiclav
  • UTI/ catheter = Co amoxiclav, Nitrofurantoin, change catheter
  • Surgical site infection = flucloxacillin
  • Central line etc = replace line or antibiotic line lock with vancomycin if unable to replace

Question 25

What is atelectasis?

Answer 25

= basal alveolar collapse when airways become obstructed by bronchial secretions

• Dyspnoea + hypoxaemia at 72 hours post op
• Manage = sit them upright, chest physio

Question 26

What is post op ileus?

Answer 26

• Due to extensive handling of bowel resulting in reduced bowel peristalsis = pseudo-obstruction
• Presentation
  
  • Abdo distension, abdo pain, N&V, inability to pass flatus, inability to tolerate oral diet
• Management
  
  • NBM then small sips of clear fluid
  • NG if vomiting
  • IV fluids (+ electrolytes to correct any disturbances)
  • TPN

Question 27

What scoring systems would you use to assess sepsis?

Answer 27

• Use the SOFA score to quantify the level of organ dysfunction
• qSOFA is a shortened score to allow rapid assessment of potential sepsis, based on clinical signs
  
  • criteria:
    
    • RR>=22
    • Altered mental state
    • SBP<= 100mmhg

Question 28

what are the 3 different types of post op haemorrhage?

Answer 28

• Primary = within intra operative period, resolve within op
• Reactive = within 24 hours of op
  
  • Typically from a ligature that slips or a missed vessel
  • They are missed due to intraop hypotension and vasoconstriction (so only bleed once pressure normalises)
• Secondary = 7-10 days post op
  
  • Typically due to erosion of a vessel from spreading infection

Question 29

how would post op haemorrhage present?

Answer 29

• Tachycardia, dizziness, agitation, visible bleeding, decreased urine output, raised resp rate (most sensitive)

Question 30

How would you manage post op haemorrhage?

Answer 30

• A-E, fluid resus
• Direct pressure on bleeding if visible
• Urgent senior surgical review + imaging to assess bleeding
• Urgent blood transfusion in mod-severe
  
  • Severe = RBC, platelets, Fresh frozen plasma
  • Activate the major haemorrhage protocol

Question 31

What are some specific examples of post op haemorrhage to be aware of?

Answer 31

• Neck = thyroidectomy and parathyroidectomy bleeding can cause severe airway obstruction
• Inferior epigastric artery commonly injured at laparoscopic ports
• Angiography entry site is in the groin and external iliac artery is commonly injured.
  
  • Bleeding goes into retroperitoneum and actual puncture site is hidden by inguinal ligament
  • Therefore they bleed profusely and tamponading is difficult

Question 32

What scores would you use to quantify delirium?

Answer 32

• Use Abbreviated Mental Test (AMT) and Mini Mental State Examination (MMSE) to quantify any current cognitive function
  
  • Compare with previous AMT and MMSE scores
• Confusional Assessment Method (CAM) to further quantify delirium

Question 33

What would you be sure to check in a post op patient that was delirious?

Answer 33

• Review obs chart, review drugs chart, look at surgical sites for infections, assess pain, check for constipation or urinary retention
• Do Neuro exam to rule out things like stroke