Post-op pain and DVT prophylaxis Flashcards
When does PE classically present post surgery?
- 10-12 days following surgery
- Patient straining at stool
- Venous pressure waves during straining causes thrombus to fracture and embolise
- Also surgery is major trauma, body’s response is to become more thrombotic
Pre, intra and post op features that increase risk of DVT
Pre:
* Age
* Smoker
* Obesity
* Previous DVT
* Malignancy
Intra:
* Prolonged immbolity
* Positioning - stasis of venous blood
* Surgical trauma
* Anaesthesia
Post-op:
* Similar to pre-op
* + prolonged immbolity
* Dehydration
* Infection
* Inflammation
What should all patients have as risk assessment?
VTE risk assessment
* All offered mechanical prophylaxis unless contraindicated
* Consider and assess need for pharmacological
Contraindications to mechanical VTE prophylaxis eg IPC and graduated compression socks
- Peripheral oedema
- Peripheral arterial disease
- Local skin conditions eg dermatitis, gangrene that could be irritated
Methods to reduce risk of DVT
- Pre-op mobilisation
- Post op mobilisation as early as possible
- Graduated compression stockings aka anti-embolism stockings
- Intraop intermittent calf compression
- Maintain hydration
- Stop pro-thrombotic drugs (eg COCP)
How do graduated compression stockings reduce risk of DVT?
- Highest pressure at ankle with reducing pressure moving proximally
- Aid venous return
- Reduce venous stasis
LMWH works synergistcally with stockings
DVT pharm prophylaxis
- LMWH - often Dalteparin
Why have some studies shown LMWH is as effective starting 12 hours post surgery than pre-op?
- LMWH has rapid onset of action
- Risk highest 2-10 days following surgery
- Balancing anticoagulation and bleed risk
- Higher bleed risk can occur within surgery if given LMWH before
- Patient compliance may be better if only have after surgery
- May coincide with early mobilisation - confounder?
Dose of Dalteparin for DVT prophylaxis
- 5000 units for all patients (unless under 50kg)
- 2500 if eGFR <30mls but UFH often preffered if renal impairement
LMWH and epidural catheter placemetn
- LMWH can be given as long as 4hrs have passed since placement of epidural
- This is to reduce risk of epidural haematoma which can cause cord compression and neurological defecits
Why do laparascopic patients receive 2,500 dose of LMWH but day case patients don’t?
- Laparascopic - pneumoperitoneum and insufflation of abdo with CO2 could affect venous return = increase risk VTE
- Could be longer procedure?
- Could be more immobile?
What group of surgical patients should receive prophylactic Dalteparin for up to 35 days after surgery?
- Total hip replacements
- Hip fracture surgery
How can post op pain be assessed?
- Subjective - ask patient to grade patin on mild, moderate to severe
- Objective - tachycardia, tachypnoea, hypertension, sweating or flushing
At what points should you assess pain in a patient?
- When mobile
- Taking a deep breath
- When in bed
Importance of adequate pain control
- Inadequate control of post op pain = slower recovery
- Reluctant to mobilise = slower restoration in function and rehab capacity
- eg hospital acquired pneumonia due to iimpaired mucus clearance following GI surgery
Tool to use when treating pain
- WHO analgesic ladder
- Titrate starting with simple analgesics (NSAIDs, paracetamol) and then weak opiates (eg codeine) and then moving up to strong opioids if needed (eg morphine)
- Consider alternatives to oral route
- Neuropathic pain may respond better to alternatives eg amitryptyline or gabapentin
- As patients recover, move down ladder
