Perioperative anti-inflammatory prescribing, based on Dr Halvey's algorithm (Halvey EJ, Haslam N, Mariano ER. BJA Education 2023).
1. Rule out contraindications (tick any present)
Decision support only - confirm against current product information and local guidance, and use clinical judgement for the individual patient.
Post-arthroplasty VTE prophylaxis: aspirin vs rivaroxaban
Select the procedure and tick any factors present. The tool suggests a pathway, weighing VTE risk against bleeding risk. Set the exact thresholds and agents to your protocol.
Procedure
Higher VTE risk factors
Higher bleeding risk factors
Evidence (decision support only):
- CRISTAL (JAMA 2022, Australian, 31 hospitals): enoxaparin 40 mg was superior to aspirin 100 mg for 90-day symptomatic VTE (1.8% vs 3.3%) after THA/TKA. Aspirin is not optimal for every patient.
- EPCAT II (NEJM 2018): after 5 days of rivaroxaban, switching to aspirin was non-inferior to continuing rivaroxaban in selected patients - supporting aspirin for lower-risk patients after an initial potent agent.
- Duration guide: extended prophylaxis up to ~35 days after THA and ~14 days after TKA.
| Medicine class | Action before surgery |
|---|---|
| ACE inhibitors / ARBs | Withhold 24h (omit morning of surgery) |
| Beta-blockers, CCBs | Continue |
| Diuretics | Omit morning of surgery |
| Warfarin | Stop ~5 days; bridge per indication/INR target |
| DOACs (apixaban, rivaroxaban, dabigatran, edoxaban) | Stop ~2-3 days; longer if reduced CrCl / high bleed-risk surgery (see SCGH CrCl table) |
| Clopidogrel / ticagrelor / prasugrel | Stop ~5-7 days (weigh stent / ACS risk) |
| Aspirin (low dose) | Usually continue |
| SGLT2 inhibitors | Stop 3 days (ketoacidosis risk) |
| GLP-1 agonists | Continue; modified fasting, consider gastric stasis |
| Metformin / oral hypoglycaemics | Omit on day of surgery |
| Insulin | Dose-adjust per fasting protocol (basal 50%) |
| NSAIDs | Stop 2-3 days (bleeding/renal). Coxibs: little platelet effect |
| Statins, antidepressants, antiepileptics, inhalers | Continue |
| Steroids | Continue; consider stress dosing |
| Oestrogen / HRT / COCP | Consider stopping per VTE risk |
| Supplements (fish oil, vitamin E, garlic, ginkgo, ginseng, St John's Wort) | Stop ~7 days |
Confirm intervals against the SCGH peri-operative medication guideline before use.
Discharge opioid reference (knee / hip)
| Procedure | Typical discharge supply (set to your protocol) |
|---|---|
| Total knee replacement | e.g. tapentadol SR + IR, limited supply, wean by ~6 weeks |
| Total hip replacement | e.g. tapentadol SR + IR, smaller supply than TKR |
Oral morphine equivalent (OME) quick calc
Approximate conversion factors - verify before relying on them. Enter total mg taken.
Total OME: 0 mg
Actual patient opioid-consumption follow-up should be captured in your Microsoft Forms / tenant, not on this website.
Direct links and codes for each plan
Give the patient the direct link (or the code). The link opens their plan straight away - they do not have to choose it from the list. Click a link to open it now.
| Plan | Code | Direct link |
|---|---|---|
| General - etoricoxib | GEN-ETO | /tools/pain-relief.html?c=GEN-ETO |
| General - celecoxib | GEN-CEL | /tools/pain-relief.html?c=GEN-CEL |
| General - ibuprofen | GEN-IBU | /tools/pain-relief.html?c=GEN-IBU |
| General - tapentadol + etoricoxib | GEN-TAP-ETO | /tools/pain-relief.html?c=GEN-TAP-ETO |
| General - tapentadol + celecoxib | GEN-TAP-CEL | /tools/pain-relief.html?c=GEN-TAP-CEL |
| General - tapentadol + ibuprofen | GEN-TAP-IBU | /tools/pain-relief.html?c=GEN-TAP-IBU |
| Caesarean section | CAES | /tools/pain-relief.html?c=CAES |
| ACL reconstruction - celecoxib | ACL-CEL | /tools/pain-relief.html?c=ACL-CEL |
| ACL reconstruction - etoricoxib | ACL-ETO | /tools/pain-relief.html?c=ACL-ETO |
| ACL reconstruction (teenager) - tramadol | ACL-PAEDS-TRAM | /tools/pain-relief.html?c=ACL-PAEDS-TRAM |
| ACL reconstruction (teenager) - oxycodone | ACL-PAEDS-OXY | /tools/pain-relief.html?c=ACL-PAEDS-OXY |
| Knee replacement - tapentadol SR 100 mg | KNEE-100 | /tools/pain-relief.html?c=KNEE-100 |
| Knee replacement - tapentadol SR 50 mg | KNEE-50 | /tools/pain-relief.html?c=KNEE-50 |
| Knee replacement - Targin 10/5 mg | KNEE-TGN-10 | /tools/pain-relief.html?c=KNEE-TGN-10 |
| Knee replacement - Targin 5/2.5 mg | KNEE-TGN-5 | /tools/pain-relief.html?c=KNEE-TGN-5 |
| Hip replacement - tapentadol SR 50 mg | HIP-50 | /tools/pain-relief.html?c=HIP-50 |
| Hip replacement - Targin 10/5 mg | HIP-TGN-10 | /tools/pain-relief.html?c=HIP-TGN-10 |
| Hip replacement - Targin 5/2.5 mg | HIP-TGN-5 | /tools/pain-relief.html?c=HIP-TGN-5 |
| Hip and knee (older cards) - patient picks knee or hip | JOINT | /tools/pain-relief.html?c=JOINT |
The full link is https://drhalvey.com.au/tools/pain-relief.html?c=CODE
(replace CODE). You can text or email this to the patient, or set up your SMS to include it.
References: Halvey EJ, Haslam N, Mariano ER. Non-steroidal anti-inflammatory drugs in the perioperative period. BJA Education 2023;23(11):440-447. Haslam N, Halvey E, Scott C. Perioperative care of patients undergoing total hip arthroplasty. BJA Education 2024;24(6).