Pre-op, Peri-op and Post-op Mx Flashcards
What type of analgesia do we need to be careful with using anticoagulants?
Spinal epidural > Spinal epidural haematoma can occur
What do we do with HRT/OCP pre-op?
Stop it 4 weeks before major surgery
Restart 2-weeks after if mobile
NBM prep for elective surgery?
Not > 2 hours for clear fluids
not > 6 hours for solids
2-3 hours before surgery = carbohydrate rich drink + avoid IV fluids
How much blood to order for gastrectomy and AAA?
Gastrectomy = 4 units
AAA = 6 units
What prophylactic ABx for GI / vascular / MRSA +ve surgery?
GI = Ceftriaxone and met Vasc = co-amox
MRSA+ve = vancomycin
Give all 1 hour prior to surgery
Management of insulin dependents pre-surgery?
Atop long acting night before
Omit AM insulin
First in to surgery
Sliding scale until tolerating food post op
How to manage steroid dose pre-surgery?
Major surgery = hydrocortisone 50-100mg IV pre-surgery, then TDS for 3/7 after
Minor surgery = just the one off dose
Managing warfarin pre-surgery?
If low risk e.g. AF - stop 5 days prior, restart next day
If high risk, stop 5 days prior.
Bridge with LMWH until 12 hours prior
Restart this and warfarin next day
ASA grades for surgery?
1 = localised surgical pathology, no systemic affect 2 = mild systemic disease 3 = severe systemic that limits activity 4 = severe systemic disease that is constant threat to life 5 = moribund, wot survive without surgery
Disinfection vs sterilisation ?
Disinfection = reduction in numbers of viable organisms
Sterilisation = removal of all organisms and spores
Autoclaving vs glutaraldehyde vs Ethylene oxide ?
Autoclaving = air removed and high temp pressures
- Most re-usable surgical equipment
- must be cleaned first
Glutaraldehyde = for endoscopes and laparoscopic stuff
- staff can develop allergies
Ethylene oxide = 3% gas with CO2
- for package materials that can’t be heated
Benefit and downfall of femoral lines?
Benefit = easy Risk = higher infection rates
Pulmonary arterial lie - what does it measure, what does this essentially measure and interpretation?
Measure pulmonary artery occlusion pressure = LEFT ATRIAL PRESSURE
Interpretation:
normal = 8-12mmHg
Low <5 = hypovolaemic
Low with pulmonary oedema = ARDS
High > 18 = overloaded
Airway management - oropharyngeal?
Easy to use
No paralysis
Short procedures
Airway management - LMA?
Easy, no paralysis
Sits in pharynx
Poor control against gastric reflux, not suitable for high pressures
Useful in day surgery
Airway management - tracheostomy?
Reduces work of breathing and anatomical dead space
Useful In weaning from mechanical
needs humidified air
Airway management - ET tube?
Optimal control
High pressures can be used
Errors in insertion = oesophageal intubation, so measure CO2 tidal volume
Paralysis needed
5 general principles of anaesthesia?
Induction = propofol Muscle relaxation = suxamethonium Airway control Maintenance = halothane End = switch to 100% oxygen
Anaesthetics - Propofol
Rapid onset, pain on IV
Rapidly metabolised = little metabolites
Anti-emetic
Moderate cardiac depression
Anaesthetics - Sodium thiopentone?
RSI
Metabolites build up quickly
Little analgesic effect
Marked myocardial depression
Anaesthetics - Ketamine?
Induction
Moderate - strong analgesic
Little myocardial depression = good in unstable patients
May induce dissociative state = nightmares
Anaesthetics - Etomidate?
No analgesic
Favourable cardiac safety profile
Cannot be used for maintenance as prolonged use = adrenal suppression
Post-op vomiting common
Anaesthesia related complications of: Propofol Suxamethonium Intubation Loss of pain sensation Loss of muscle power Pseudocholinesterase deficiency
Propofol = cardiorespiratory depression
Suxamethonium = Malignant hyperthermia (Mx = dantrolene)
Intubation = trauma or oesophageal intubation
Loss of pain = Retention, pressure sores and nerve palsies
Loss of power = corneal abrasions and atelectasis
Pseudocholinesterase deficiency = increased duration of muscle relaxants
Malignant hyperthermia - mechanism, cause, Ix and Mx?
Due to the excessive release of calcium from sarcoplasmic reticulum of skeletal muscle
= Pyrexial and rigidity
Halothane and suxamethonium
CK raised
Dantrolene
why is pain management necessary?
Causes increased autonomic activation = arteriolar constriction = reduced would perfusion = reduced healing
Reduced mobility = DVT
Reduced cough = atelectasis and pneumonia
How does paracetamol work, how is it absorbed and metabolised.
Inhibits prostaglandin synthesis
Orally absorbed
Metabolised by LIVER
How do NSAIDs work and contraindications?
Inhibit cox which usually catalyses arachidonic acid to prostaglandins
Peptic ulceration, bleeding, renal disease and asthma
How does morphine get metabolised and SE’s?
Metabolised by liver = reduced clearance in liver disease / elderly
SE’s = N+V, constipation, resp depression
Pethidine - how is it metabolised?
By kidneys
In renal failure can accumulate = twitching and convulsion
Local anaesthetics - lidocaine > mechanism, metabolism and excretion.
Blocks sodium channels - although. activated first = pain
Hepatic metabolism
Protein bound
Renal excreted
Local anaesthetics - lidocaine toxicity?
CNS overactivity Cardiac arrhythmias = contraindicated in: - Current flecainide Mx - 3rd degree HB no PPM - Severe SAN - Accelerated idioventricular rhythm
Local anaesthetics - bupivacaine = mechanism, duration compared to lidocaine and SE’s?
Binds to intracellular portion of Na channels = blockage influx
Longer duration vs lidocaine. So used at end of surgery to infiltrate the wound
SE’s = cardiotoxic so contraindicated I regional blockade
Local anaesthetics prilocaine - Mechanism, use, and toxicity?
Binds to intracellular portion of Na channels = blockage influx
Regional blocks e.g. biers blockade
Can cause methaemoglobinaemia = cyanosis and dyspnoea
Mx»_space; Methylene blue
What kind of amino group do procaine and benzocaine have?
Amino-ester group
Doses with and without adrenaline of BLP?
Bupivicaine = 2mg and 2mg with adrenaline. Toxicity is related to protein binding and adrenaline won’t change this
Lidocaine = 3mg then 7mg
Prilocaine = 6mg then 9mg
Symptoms and management of local anaesthetic OD?
Circumoral paraesthesia
Tinnnitus and low GCS
Mx = stop anaesthetic, high flow oxygen and lipid emulsion e.g. intralipid 20% bolus
If prilocaine = methylene blue
Spinal anaesthesia - use, benefit and SE’s?
Used in lower half of body surgery
Pain relief can last many hours after surgery
SE’s = nausea, hypotension, retention, sensory and motor block
Epidural anaesthesia - Use, SE’s?
Used for major abdominal surgery, helps prevent post-op respiratory compromise
SE’s:
Confined to bed
Need urinary catheter = immobile and infection
Contraindicated In coagulopathies = haematoma
TAP - Mechanism, use and disadvantage?
USS to find correct muscle plane, inject local and it diffuses and blocks spinal nerves
Used in extensive laparoscopic surgery. Provides wide block with no post-op motor impairment
disadvantage = limited by half-life of agent chosen
Neuropathic pain Mx?
First line = amitriptyline or gabapentin
2nd line = combine the 2
Diabetic neuropathic = duloxetine
Muscle relaxants - only depolarising type?
Suxamethonium
Muscle relaxants - Suxamethonium - Mechanism and SE’s?
Inhibits ratio of Ach at NMJ
Degraded by cholinesterase and ACh
Fastest onset and shortest duration
Generalised muscle contraction prior to paralysis
SE’s = malignant hyperthermia, hyperkalaemia, delayed recovery
Muscle relaxants - Atracarium - Mechanism, duration, excretion, SE’s and reversal?
non-depolarising neuromuscular blocking drug
30-45 minutes
Generalised histamine release = facial flushing, tachycardia and hypotension
Not excreted by liver or kidney = hydrolysis in tissue
neostigmine
Muscle relaxants - Vecuronium = Duration, excretion and reversal?
non-depolarising neuromuscular blocking drug
30-40 mins
Excreted by liver and kidneys
neostigmine
Muscle relaxants - Pancuronium - Onset, duration and reversal
non-depolarising neuromuscular blocking drug
2-3 mins
2 hours
neostigmine
Tourniquets - post inflation effects?
SVR, BP and CVP increase
Core temperature increases
Hyper-coagulable
Tourniquets - post deflate effects?
Decrease in CVP, SVR and BP + core temperature
Increase end tidal volume
Fibrinolysis
Raised serum K and lactate
Tourniquets - contraindications?
AV fistula
Severe PVD
Previous vascular surgery
Current # or thrombosis
Tourniquets - local side effects?
Damage to muscle, vessels and skin
neuropraxia - risk increased by besmirch bandage tourniquet
Management of bleeding - superficial dermal bleeding?
Usually. ceases
Troublesome = diathermy
Scalp = mattress sutures
Management of bleeding - Superficial arterial vs major arterial?
Major venous?
Raw surfaces?
Superficial arterial = clip and ligate
Major arterial = clip and ligate, but if can’t identify it, pack first !
Major venous:
Apply digital pressure
Divided veins need ligation
Incomplete laceration = stinky clamp + 5/0 prolene
Raw surfaces:
Spray diathermy or Argon coagulation
Splenic injury = specifically argon coagulation
Diathermy - what is used in colonoscopic polypectomy?
Mixture of cutting and coagulation
Diathermy - cutting mode?
non-modulated sinusoidal
High power and current
Vaporisation
Diathermy - Coag?
Modulated current, intermittent dampened sine waves
High peak voltage
Evaporation
Diathermy - Desiccation?
Low current, high voltage
Loss of cellular water but no protein damage
Diathermy - fulguration?
Spray affect
Local superficial tissue destruction
Low amplitude and high voltage
How does a CUSA device work?
High frequency US oscillations
Seal and coagulate tissue
e.g. brain resection
Sutures - How are absorbable ones broken down?
Which surgeries dow we always use non-absorbable?
Macrophages hydrolyse material
Cardiac and vascular
Sutures - braided vs monofilament?
Braided = better handling, but higher bacterial count
Unsuitable for vascular as potentially thrombogenic
Sutures - silk - type, durability, use?
Braided biological
Theoretically permanent
Use = anchoring devices and skin closure
Sutures - Polydiaxone (PDS) - Type, durability and use?
Synthetic monofilament
3 months
Widespread surgical use = visceral anastomoses, dermal closure and abdominal wound closure
Sutures - Polyglycolic acid (Vicryl and Dexon) - Type, durability and use?
Synthetic braided
6 weeks
Most tissues
Sutures - Polypropylene (Prolene) - Type, duration and use?
Synthetic monofilament
PERMANET
Vascular anastomoses
Sutures - Polyester (ethibond) - Type, durability and use?
Synthetic braided
PERMANENT
Laparoscopic surgery
Complications of surgical drain?
Infection + fistula
What drain is used in CNS?
Low suction / free drainage
e.g. subdural haematoma
What drain for cardiothoracic stuff?
Underwater seal
Can put on suctions if there is some air leak
Why are drains used in GI surgery?
To prevent or drain abscesses
To turn anticipated complication e.g. bile leak, into a manageable one
What is a redivac?
Suction type drain
Propylene
Closed system
High pressure
Example of a low pressure drain?
Wallace Robinson
These have lower risk of fistulation = used in abdo surgery
Can be emptied and repressurised
When do you use latex drains?
CBD exploration
Come In T-shape or straight
Used if want to generate fibrosis along the tract
Wound closure - primary vs delayed primary vs vacuum assisted
Primary = surgical wound, clean, primary intention
Delayed primary = if infection and primary not achievable
Vacuum assisted - sponge on wound, negative pressure applied. Removes exudate but risk of fistulation
Split thickness graft. - what is taken, how does the remaining skin regenerate, how can size be increased + can donor site be reused?
Superficial dermis using Watson knife
Remaining epithelium regenerates from dermal appendages
Coverage can be increased by mesh, but decreases cosmesis
Donor site can be reused
Pre-tibial laceration - how to close wound?
Heal poorly
Need split thickness skin graft
Full thickness graft - common use, what layers removed?
Commonly for facial reconstruction
Whole dermal layer used
Donor site morbidity
Types of flaps?
Viable tissue with own blood supply
Pedicles = more reliable but limited with range
Free = > range but increased risk of breakdown as need vascular anastomoses
Some examples of immediate, early and late surgical complications?
Immediate = intubation issues, surgical trauma and bleeds
Early = VTE, Infection, retention, ABx associated colitis
Late = Scarring, neuropathy and recurrence / failure
2 big causes of post-op retention?
Drugs - opioids + Anti-ACh
Pain = sympathetic activation = sphincter contraction
Post-op pyrexia causes - early vs late?
Early = up to 5 days
Blood transfusion, physiological, pulmonary atelectasis + infection
Late > 5 days:
Pneumonia, VTE, wound infection, collection and anastomotic leak.
Post-op pyrexia:
Swinging fevers post ileal resection
Abdo pain
Inflamm markers up
Anastomotic leak
Post-op pyrexia:
Post midline laparotomy and GA
Dull at bases
Atelectasis = alveolar collapse
Mx = analgesia and chest physio
Post-op pyrexia:
oozing wound and raising inflammation markers
Classification?
Mx?
Wound infection, commonly S. Aureus
Clean = doesn’t break viscus
Clean and contaminated = breach viscus not colon
Contamiated = breach viscus and colon
Post-op pyrexia:
Malaise, swinging fevers with a localised peritonitis?
Collection
needs antibiotics and drainage
Post-op pyrexia:
Pain, swelling and warmth
Where cannula had been inserted
Cellulitis
B-haemolytic strep
Antibiotics
Pink serosanguinous fluid is coming from wound 10 days post op?
Mx options?
Wound dehiscence
On ward = IV Abx, IVF, Analgesia and covered in saline impregnated gauze
Then to theatres:
- Re-suture if healthy tissue
- Wound manager - if some granulation tissue or high output fistula with wound
- Bogota bag - as a temporary measure until surgery, clear plastic bag cut and sutured to edges
- VAC dressing
Who would get thromboprophylaxis for surgery?
> 90 mins or > 60 for LL/pelvis surgery
Thrombophilia, malignancy, known varicose + phlebitis
Acute admission with inflammation of abdomen
Expected reduced mobility
Previous DVT
Age >60, BMI > 30
How does LMWH work vs unfractionated vs. dabigatran
LMWH = binds to antithrombin to inhibit Xa
Unfract. = Binds antithrombin 3 = affects thrombin and Xa
Dabigatran = Direct thrombin inhibitor
causes and Mx of post op reduced urine output?
Pre-renal = hypovolaemic Renal = commonly drugs e.g. NSAIDs or gentamicin Post-renal = retention or blocked catheter
Mx: Fluid status Check catheters and stomas etc Check drug chart Flush all instruments Fluid challenge
Specific surgical complications:
Cholecystectomy?
5% converted to open
Bile leak
Retained stones needing ERCP
Fat intolerance / loose stool
Specific surgical complications:
Appendicectomy?
Abscess
Damage to fallopian tubes
Right heme-colectomy
Specific surgical complications:
Inguinal hernia?
Early = haematoma, retention and infection
Late = chronic pain, ischaemic orchitis, recurrence
Specific surgical complications:
Colonic surgery?
Early = ileus, anastomotic leak, fistula, abscess
Late = Adhesions causing obstruction, incisional hernia
Specific surgical complications: Ileus
Symptoms, causes and Mx?
Distension, constipation / vomiting + absent bowel sounds
Causes:
Bowel handling, infection, hypokalaemia, metoclopramide, pancreatitis
Mx:
NGT, drip and suck
NBM
IVF
Specific surgical complications:
Anorectal?
Incontinence
Stenosis
Annal fissure
Specific surgical complications:
Vascular?
Anastomotic leak Ischaemia Thrombosis / emboli Infection Aorto-enteric fistula
Specific surgical complications:
Splenic surgery?
Thrombocytosis = VTE
Gastric dilation secondary to small bowel ileus
Infection with encapsulated. bugs
Specific surgical complications:
Thyroid?
Recurrent laryngeal nerve
Tracheal obstruction secondary to haematoma
Hypoparathyroid
Specific nerve injuries in surgery: Hypoglossal Accessory Long thoracic Recurrent laryngeal Ulnar + median Sciatic Superior gluteal Common peroneal
Hypoglossal - carotid endarterectomy
Accessory - posteiror triangle LN biopsy
Long thoracic - Axillary node clearance
Recurrent laryngeal - thyroid surgery
Ulnar + median - Upper limb # repairs
Sciatic - Posteiror approach
Superior gluteal - anterolateral approach
Common peroneal - legs In Lloyd Davies position
Specific visceral / structural injuries in surgery: Thoracic duct Parathyroid glands Ureters Bowel perforation Bile duct injury Facial nerve injury Tail of pancreas Testicular vessels Hepatic veins
Thoracic duct - any thoracic surgery
Parathyroid glands - difficult thyroid surgery
Ureters - colonic / gynae surgery
Bowel perforation - use of Verres needle
Bile duct injury - not delineating clots triangle
Facial nerve injury - parotidectomy
Tail of pancreas - legating splenic hilum
Testicular vessels - re-do ope inguinal repair
Hepatic veins - liver mobilisation
What is post-op cognitive deterioration, and early vs late. causes?
Deterioration in. performance on battery of tests expected in <3.5% of controls
Early = Duration of anaesthesia, GA, re-op, post-op infection, increasing age
Late = increasing age, emboli, biochemical disturbance
Prepping for endoscopic procedures?
ERCP = clotting, antibiotics OGD = NBM 6 hours prior Flexi-sig = enema 30 mis prior Colonoscopy = stop ferrous fumerate 7 days prior. If U+E's okay give PO laxatives
