Preoperative Preparation

Question 1

Overview preoperative preparation for Respiratory patient

Answer 1

Question 2

Overview preoperative preparation for CVS patient

Answer 2

Risk of post opt AMI in general
Population: 0.5%

Recent MI ( risk of post opt AMI)
- <3months: 30%
- 3-6months: 15%
- >6months: 6%

If AMI post opt, risk of mortality >60%

🩺 Drug-Eluting Stent (DES) vs Bare-Metal Stent (BMS)

🔹 Drug-Eluting Stent (DES)
✅ Benefits
🚫 ↓ Restenosis (re-narrowing) – drug coating inhibits neointimal hyperplasia
🔁 ↓ Need for repeat revascularization
💪 Better outcomes in complex lesions (e.g. diabetes, small vessels)

⚠️ Considerations
⏳ Requires longer dual antiplatelet therapy (DAPT)
💰 Higher cost

🔸 Bare-Metal Stent (BMS)
✅ Benefits
⏱️ Shorter DAPT – ideal if high bleeding risk or need for surgery soon
💵 Cheaper

⚠️ Considerations
📈 ↑ Risk of restenosis
👎 Less effective in complex lesions

Why DES Requires Longer DAPT:
1. Delayed Endothelialization
* The anti-proliferative drugs (e.g. sirolimus, paclitaxel) slow the healing of the stent’s inner surface.
* This leaves the stent exposed to blood longer, increasing the risk of thrombosis.
2. Higher Risk of Late Stent Thrombosis
* DES can cause late and very late stent thrombosis, which may occur months or years after implantation.
* DAPT (e.g., aspirin + clopidogrel) is essential to prevent platelet aggregation on the stent surface.
3. BMS Heals Faster
* BMS gets covered with endothelium relatively quickly (~1 month), so platelets have less exposed metal to adhere to.
* Hence, shorter DAPT is sufficient.

⸻

DAPT Duration Guidelines (General)
* BMS: ≥1 month
* DES (1st gen): ≥12 months
* DES (2nd gen, newer): ≥6 months (can be shorter if bleeding risk is high)

Question 3

Overview preoperative preparation for Renal patient

Answer 3

Question 4

Overview preoperative preparation for DM patient

Answer 4

Steroid coverage during surgery is necessary for patients on long-term steroid therapy because their adrenal glands may not produce adequate levels of cortisol in response to the stress of surgery. This is due to adrenal suppression, a condition where prolonged use of exogenous (external) steroids suppresses the hypothalamic-pituitary-adrenal (HPA) axis.

1. Adrenal Suppression: Long-term steroid use can reduce the body’s ability to produce cortisol naturally. In stressful situations like surgery, the body requires higher cortisol levels to help with stress response, glucose metabolism, and inflammation control. Without supplementation, there is a risk of adrenal crisis, which can be life-threatening.
2. Prevention of Adrenal Crisis: Adrenal crisis is a state of acute adrenal insufficiency that can lead to hypotension, shock, and even death. Supplemental steroids ensure that there is enough cortisol available during and after surgery to prevent this condition.
3. Inflammatory Response Control: Cortisol plays a key role in modulating inflammation. Without adequate levels of cortisol, the body’s response to surgical trauma can result in excessive inflammation, delaying healing and increasing the risk of complications.
4. Maintenance of Blood Pressure and Glucose: Cortisol helps maintain normal blood pressure and glucose levels. Insufficient cortisol during surgery can result in hypotension and hypoglycemia, both of which are dangerous during surgery.

For these reasons, “stress-dose” steroids are often administered to cover the period of surgery and the immediate postoperative phase to compensate for the lack of natural cortisol production. The dosage depends on the type of surgery and the patient’s baseline steroid use.

Question 5

Overview of Preoperative optimization for general patient ( high risk operation)

Answer 5

Question 6

Patient with antiplalelet or warfarin that came with LGIB

Answer 6