1 Flashcards
what is the difference between a cross match and group and save?
Group and save refers to sending off a sample of the patient’s blood to establish their blood group. The sample is saved in case they require blood to be matched to them for a blood transfusion. A group and save is done routinely where there is a lower probability that they will require blood products. No blood is assigned to the patient at this stage. A group and save sample will only be valid for a certain period (e.g., 7 days) depending on the local trust policy, after which a repeat sample is required.
Crossmatching involves the process of actually taking a unit or more of blood off the shelf and assigning it to the patient in case they need it quickly. This is done where there is a higher probability that they will require blood products, so that the blood is ready to go if required.
why is fasting required before surgery and normally how long do you have to go without food and fluids
to ensure they have an empty stomach for the duration of their operation. The aim is to reduce the risk of reflux of food around the time of surgery (particularly during intubation and extubation), which subsequently can result in the patient aspirating their stomach contents into their lungs.
Fasting for an operation typically involves:
6 hours of no food or feeds before operation
2 hours no clear fluids (fully “nil by mouth”)
if there is an acutely unwell surgical patient and there is a possibility they may need surgery what should you do?
Acutely unwell surgical patients that potentially require emergency surgery are made nil by mouth and given maintenance IV fluids.
what medications should you stop before surgery?
- anticoagulants
- For patients on warfrin need to ensure that there INR is brought back to normal.
- warfarin can be rapidly reversed with vitamin K in acute scenarios.
Treatment dose low molecular weight heparin or an unfractionated heparin infusion may be used to bridge the gap between stopping warfarin and surgery in higher-risk patients (e.g., mechanical heart valves or recent VTE), and stopped shortly before surgery depending on the risk of bleeding and thrombosis.
DOACs (e.g., apixaban, rivaroxaban or dabigatran) are stopped 24-72 hours before surgery depending on the half-life, procedure and kidney function.
Oestrogen-containing contraception (e.g., the combined contraceptive pill) or hormone replacement therapy (e.g., in perimenopausal women) need to be stopped 4 weeks before surgery to reduce the risk of venous thromboembolism.
How should manage people on long-term corticosteroids (equivalent to more than 5mg of oral prednisolone) before surgery?
Surgery adds additional stress to the body, which normally increases steroid production. In patients on long-term steroids, there is adrenal suppression that prevents them from creating the extra steroids required to deal with this stress. Management involves:
- Additional IV hydrocortisone at induction and for the immediate postoperative period (e.g., first 24 hours)
- Doubling of their normal dose once they are eating and drinking for 24 – 72 hours depending on the operation
which diabetes drugs should be adjusted or omitted during surgery ?
The stress of surgery increases blood sugar levels. However, fasting may lead to hypoglycaemia. In general, the risk of hypoglycaemia is greater than hyperglycaemia.
Sulfonylureas (e.g., gliclazide) can cause hypoglycaemia and are omitted until the patient is eating and drinking
Metformin is associated with lactic acidosis, particularly in patients with renal impairment
SGLT2 inhibitors (e.g., dapagliflozin) can cause diabetic ketoacidosis in dehydrated or acutely unwell patients
How should you manage patients on insulin before surgery?
In patients on insulin going for surgery (follow the local policy):
- Continue a lower dose (BNF recommends 80%) of their long-acting insulin
- Stop short-acting insulin whilst fasting or not eating, until eating and drinking again (hypo risk)
Have a variable rate insulin infusion alongside a glucose, sodium chloride and potassium infusion (“sliding-scale”) to carefully control their insulin, glucose and potassium balance
what are the steps for VTE prophylaxis before surgery?
4
Low molecular weight heparin (LMWH) such as enoxaparin
DOACs (e.g., apixaban or rivaroxaban) may be used as an alternative to LMWH
Intermittent pneumatic compression (inflating cuffs around the legs)
Anti-embolic compression stockings
what conditions are NSAIDS inappropriate or contraindicated in?
Asthma
Renal impairment
Heart disease
Stomach ulcers
Prophylactic antiemetics are often given at the end of the procedure by the anaesthetist to prevent PONV from occurring. Common options for prophylaxis given at the end of the operation are…
Ondansetron (5HT3 receptor antagonist) – avoided in patients at risk of prolonged QT interval
Dexamethasone (corticosteroid) – used with caution in diabetic or immunocompromised patients
Cyclizine (histamine (H1) receptor antagonist) – caution with heart failure and elderly patient
Examples of “rescue” antiemetics used in the post-operative period if nausea or vomiting occur are…
Ondansetron (5HT3 receptor antagonist) – avoid in patients at risk of prolonged QT interval
Prochlorperazine (dopamine (D2) receptor antagonist) – avoid in patients with Parkinson’s disease
Cyclizine (histamine (H1) receptor antagonist) – caution with heart failure and elderly patients
what is the risk when removing a catheter particularly in male patients
Removal of a catheter is called a trial without catheter (TWOC). It is called this as there is a risk the patient will find it difficult to pass urine normally and go into urinary retention, and the catheter may need to be reinserted for a period before removal can be tried again. This is quite common, more so in male patients.
Good nutrition is important for healthy wound healing and overall recovery from surgery. What is entral feeding?
Where possible, patients should get their nutrition via their gastrointestinal tract. Having nutrition via the gastrointestinal tract is called enteral feeding. This could be by:
-Mouth
-NG tube
Percutaneous endoscopic gastrostomy (PEG) – a tube from the surface of the abdomen to the stomach
Good nutrition is important for healthy wound healing and overall recovery from surgery.
What is total parenteral nutrition.
Total parenteral nutrition (TPN) involves meeting the full ongoing nutritional requirements of the patient using an intravenous infusion of a solution of carbohydrates, fats, proteins, vitamins and minerals.
This is used where it is not possible to use the gastrointestinal tract for nutrition. It is prescribed under the guidance of a dietician.
TPN is very irritant to veins and can cause thrombophlebitis (is an inflammatory process that causes a blood clot to form and block one or more veins, usually in the legs.) , so is normally given through a central line rather than a peripheral cannula.
what is atelectasis?
where a portion of the lung collapses due to under-ventilation
