Preoperative management Flashcards
What are the aims of pre operative assessment?
Informed consent
Assess risk vs. benefits
Optimise fitness of patient
Check anaesthesia / analgesia type c¯ anaesthetist
What pre operative checks are carried out?
OP CHECS
Operative fitness: cardiorespiratory comorbidities
Pills
Consent
History
MI, asthma, HTN, jaundice
Complications of anaesthesia: DVT, anaphylaxis
Ease of intubation: neck arthritis, dentures, loose teeth
Clexane: DVT prophylaxis
Site: correct and marked
What are pre operative considerations for anti-coagulants?
Balance risk of haemorrhage c¯ risk of thrombosis
Avoid epidural, spinal and regional blocks
What are pre operative considerations for anti epileptic drugs?
Give as usual
Post-op give IV or via NGT if unable to tolerate orally
What are pre operative considerations for OCP or HRT?
Stop 4wks before major / leg surgery
Restart 2wks post-op if mobile
How many units of blood should be cross matched for a gastrectomy?
4
How any units of blood should be cross matched for AAA?
6
When should a chest x ray be carried out as a pre op investigation?
cardiorespiratory disease/symptoms, >65yrs
When should an ECG be carried out as a pre op investigation?
HTN, Hx of cardiac disease, >55yrs
How long should a patient be NBM prior to surgery?
≥2h for clear fluids, ≥6h for solids
What are the risks of bowel prep pre surgery?
Liquid bowel contents spilled during surgery
Electrolyte disturbance
Dehydration
↑ rate of post-op anastomotic leak
What are the options for bowel prep pre surgery?
Picolax: picosulfate and Mg citrate
Klean-Prep: macrogol
In what surgeries are prophylactic abx used?
GI surgery (20% post-op infection if elective)
Joint replacement
How is DVT risk managed for low, medium and high risk?
Low risk: early mobilisation
Med: early mobilisation + TEDS + 20mg enoxaparin
High: early mobilisation + TEDS + 40mg enoxaparin +
intermittent compression boots perioperatively.
What are the ASA grades?
- Normally healthy
- Mild systemic disease
- Severe systemic disease that limits activity
- Systemic disease which is a constant threat to life
- Moribund: not expected to survive 24h even c¯ op
How should insulin dependent DM patients be managed surgically?
Put pt. first on list and inform surgeon and anaesthetist
Some centres prefer to use GKI infusions
Sliding scale may not be necessary for minor ops
Put pt. first on list and inform surgeon and anaesthetist
Some centres prefer to use GKI infusions
Sliding scale may not be necessary for minor ops
How should NIDDM patients be managed surgically?
If glucose control poor (fasting >10mM): treat as IDDM
Omit oral hypoglycaemics on the AM of surgery
Eating post-op: resume oral hypoglycaemics c¯ meal
No eating post-op
Check fasting glucose on AM of surgery
Start insulin sliding scale
Consult specialist team ore. restarting PO Rx
Diet Controlled
Usually no problem
Pt. may be briefly insulin-dependent post-op
Monitor CPG
What are the risks of steroids in a surgical patient?
Poor wound healing
Infection
Adrenal crisis
How should patients taking steroids be managed surgically?
Need to ↑ steroid to cope c¯ stress
Consider cover if high-dose steroids w/i last yr
Major surgery: hydrocortisone 50-100mg IV c¯ pre-med
then 6-8hrly for 3d.
Minor: as for major but hydrocortisone only for 24h
What are the risks of surgery in a jaundiced patient?
Pts. c¯ obstructive jaundice have ↑ risk of post-op renal
failure need to maintain good UO.
Coagulopathy
↑ infection risk: may → cholangitis
How should jaundiced patients be managed pre operatively?
Avoid morphine in pre-med
Check clotting and consider pre-op vitamin K
Give 1L NS pre-op (unless CCF) → moderate diuresis
Urinary catheter to monitor UPO
Abx prophylaxis: e.g. cef+met
How should jaundiced patients be managed intraop.?
Hrly UO monitoring
NS titrated to output
How should jaundiced patients be managed post op?
Intensive monitoring of fluid status
Consider CVP + frusemide if poor output despite NS
What should be considered in anti-coag patients?
Very minor surgery may be undertaken w/o stopping
warfarin if INR <3.5.
Avoid epidural, spinal and regional blocks if
anticoagulated,
In general, continue aspirin/clopidogrel unless risk of
bleeding is high – then stop 7d before surgery
How should patients with low thromboembolic risk be managed surgically?
Stop warfarin 5d pre-op: need INR <1.5
Restart next day
How should patients with high thromboembolic risk be managed surgically?
Need bridging c¯ LMWH Stop warfarin 5d pre-op and start LMWH Stop LMWH 12-18h pre-op Restart LMWH 6h post-op Restart warfarin next day Stop LMWH when INR >2
How should emergancy surgery in pts anticoagulated be managed?
Discontinue warfarin
Vit K .5mg slow IV
Request FFP or PCC to cover surgery
What are the risks of COPD to surgery?
Basal atelectasis
Aspiration
Chest infection
What should be done pre op for pts with COPD?
CXR
PFTs
Physio for breathing exercises
Quit smoking (at least 4wks prior to surgery)
What are the aims of anaesthesia?
hypnosis, analgesia, muscle relaxation
What are the contraindications to regional anaesthesia?
local infection, clotting abnormality
Complication of propofol induction
cardio respiratory depression
complication of intubation
Oro-pharyngeal injury c¯ laryngoscope
Oesophageal intubation
Complication of loss of pain sensation
Urinary retention
Pressure necrosis
Nerve palsies
Complication of loss of muscle power?
Corneal abrasion
No cough → atelectasis + pneumonia
What is malignant hyperpyrexia?
Rare complication ppted by halothane or suxamethonium
AD inheritance
Rapid rise in temperature + masseter spasm
Rx: dantrolene + cooling
Why is analgesia necessary post op?
Pain → autonomic activation → arteriolar constriction →
↓ wound perfusion → impaired wound healing
Pain → ↓ mobilisation → ↑ VTE and ↓ function
Pain → ↓ respiratory excursion and ↓ cough →
atelectasis and pneumonia
Humanitarian considerations
What are the pre op options for analgesia?
Epidural anaesthesia: e.g. c¯ bupivacaine
What are the end op options for analgesia?
Infiltrate wound edge c¯ LA
Infiltrate major regional nerves c¯ LA
What are the post op options for pain relief?
1. Non-opioid ± adjuvants Paracetamol NSAIDs Ibuprofen: 400mg/6h PO max Diclofenac: 50mg PO / 75mg IM
- Weak opioid + non-opioid ± adjuvants
Codeine
Dihydrocodeine
Tramadol - Strong opioid + non-opioid ± adjuvants
Morphine: 5-10mg/2h max
Oxycodone
Fentanyl
What are the aims of enhanced recovery after surgery?
Optimise pre-op preparation for surgery
Avoid iatrogenic problems (e.g. ileus)
Minimise adverse physiological / immunological responses
to surgery
↑ cortisol and ↓ insulin (absolute or relative)
Hypercoagulability
Immunosuppression
↑ speeded of recovery and return to function
Recognise abnormal recovery and allow early intervention
How can a patient be optimised pre surgery under the enhanced recovery programme?
Aggressive physiological optimisation
Hydration
BP (↑ / ↓)
Anaemia
DM
Co-morbidities
Smoking cessation: ≥4wks before surgery
Admission on day of surgery, avoidance of prolonged fast
Carb loading prior to surgery: e.g. carb drinks
Fully informed pt., encouraged to participate in recovery
How are patients on enhanced recovery programmes managed intra op?
Short-acting anaesthetic agents
Epidural use
Minimally invasive techniques
Avoid drains and NGTs where possible
How are patients on enhanced recovery programmes managed post op?
Aggressive Rx of pain and nausea
Early mobilisation and physiotherapy
Early resumption of oral intake (inc. carb drinks)
Early discontinuation of IV fluids
Remove drains and urinary catheters ASAP
What are the immediate complications of surgery?
Intubation → oropharyngeal trauma
Surgical trauma to local structures
Primary or reactive haemorrhage