General Surgery
Perioperative Care and Anaesthesia
MBBS surgery notes on perioperative care and anaesthesia: ASA grading, fasting, thromboprophylaxis and postoperative complications, mapped to NMC codes SU10 and SU11.
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Perioperative Care and Anaesthesia
MBBS surgery notes on perioperative care and anaesthesia: ASA grading, fasting, thromboprophylaxis and postoperative complications, mapped to NMC codes SU10 and SU11.
This chapter covers the care of the patient around an operation and the principles of anaesthesia. It spans preoperative risk assessment, thromboprophylaxis, the components of anaesthesia and the recognition of common postoperative complications.
High-yield: Perioperative Care and Anaesthesia
- Preoperative assessment identifies and optimises comorbidities, plans anaesthesia and estimates surgical risk.
- The American Society of Anesthesiologists grade rates fitness from I, a healthy patient, to V, a moribund patient not expected to survive without surgery.
- Fasting guidance is usually six hours for solid food and two hours for clear fluids to reduce the risk of aspiration.
- Venous thromboembolism prophylaxis combines early mobilisation, mechanical compression and low molecular weight heparin in at-risk patients.
- General anaesthesia has three components: hypnosis, analgesia and muscle relaxation, often given together as a balanced technique.
- Rapid sequence induction with cricoid pressure protects against aspiration in patients with a full stomach or reflux.
- Regional techniques such as spinal and epidural anaesthesia block pain at the cord and can avoid the risks of general anaesthesia.
- Malignant hyperthermia is a rare inherited reaction to volatile agents and suxamethonium, treated with dantrolene.
- The World Health Organization surgical safety checklist at sign-in, time-out and sign-out reduces avoidable errors.
- Postoperative nausea and vomiting is common and is managed with antiemetics and by avoiding known triggers.
- Multimodal analgesia combines paracetamol, non-steroidal drugs and opioids to control pain with fewer opioid side effects.
- Enhanced recovery after surgery programmes reduce fasting, encourage early feeding and mobilisation and shorten hospital stay.
- Common postoperative pyrexia causes follow a timeline: atelectasis early, then chest and urine infection, wound, and deep vein thrombosis later.
- Adequate preoperative control of diabetes, hypertension and anaemia reduces perioperative complications.
- Postoperative hypoxia should prompt oxygen and a search for atelectasis, chest infection, pulmonary embolism or opioid-induced respiratory depression.
Common causes of postoperative fever by timing
- **Day 1 to 2:** Atelectasis and the systemic response to surgery; encourage deep breathing and mobilisation.
- **Day 3 to 5:** Chest infection and urinary tract infection, often catheter-related.
- **Day 5 to 7:** Surgical site infection and anastomotic leak.
- **After day 7:** Deep vein thrombosis, pulmonary embolism and deep collections or abscess.
NMC competencies in this chapter
- **SU10.1:** Preoperative assessment and optimisation
- **SU10.2:** Risk assessment and thromboprophylaxis
- **SU10.3:** Postoperative care and complications
- **SU10.4:** Perioperative monitoring and fluid management
- **SU11.1:** Principles and components of general anaesthesia
- **SU11.2:** Regional and local anaesthesia techniques
- **SU11.3:** Airway management and induction
- **SU11.4:** Complications of anaesthesia
- **SU11.5:** Postoperative analgesia
- **SU11.6:** Recovery and enhanced recovery after surgery
- **SU17.1:** Resuscitation principles in the perioperative patient
Frequently Asked Questions
What does the ASA grade describe?
The American Society of Anesthesiologists grade rates preoperative physical fitness from grade I, a healthy patient, to grade V, a moribund patient not expected to survive without the operation.
What are the fasting rules before surgery?
Usually six hours without solid food and two hours without clear fluids, which lowers gastric volume and reduces the risk of aspiration during anaesthesia.
What are the three components of general anaesthesia?
Hypnosis to induce unconsciousness, analgesia to control pain and muscle relaxation to allow surgery, usually delivered together as a balanced anaesthetic technique.
How is postoperative fever approached by timing?
Atelectasis dominates in the first two days, then chest and urine infections, then wound infection and leak, and later deep vein thrombosis and collections.
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