Why Perioperative Care Is Examined
Perioperative care spans pre-operative assessment, intraoperative safety, and post-operative management. OSCEs examine it through: pre-operative assessment stations, consent communication stations, post-operative complication recognition, and clinical reasoning (this patient is unwell on day 1 post-op — what do you do?). The surgical patient is a distinct clinical entity requiring specific knowledge of risk, consent, and expected complications.
Pre-Operative Assessment — Systematic Approach
Medical History Focus
| Area | What to assess |
|---|---|
| Cardiovascular | IHD, heart failure, hypertension, arrhythmia, valvular disease |
| Respiratory | COPD, asthma, OSA (obstructive sleep apnoea) |
| Metabolic | Diabetes (HbA1c, medication plan), thyroid disease, obesity |
| Renal | CKD (contrast, NSAID risk), dialysis status |
| Haematological | Bleeding disorders, previous VTE, anticoagulation |
| Medications | Anticoagulants, antiplatelets, steroids, diabetes medications, antihypertensives |
| Allergies | Latex, antibiotics, anaesthetic agents |
| Previous anaesthetics | Difficult intubation, malignant hyperthermia, suxamethonium apnoea |
| Social | Smoking (stop 8 weeks before for wound/respiratory benefit), alcohol, recreational drug use |
Functional Capacity — METs
| METs | Activity | Significance |
|---|---|---|
| Above 10 | Vigorous sport — running, swimming | Excellent |
| 7-10 | Cycling, singles tennis | Good |
| 4-7 | Walking up two flights of stairs | Moderate — acceptable for intermediate surgery |
| Below 4 | Activities of daily living only | Poor — increased peri-operative risk |
🧠 Mnemonic
"Can you climb two flights of stairs without stopping?" This is the 4-MET threshold question. If a patient cannot manage two flights, they have poor functional capacity and are at significantly higher risk of perioperative cardiac events.
ASA Classification
| Grade | Definition | Example |
|---|---|---|
| ASA 1 | Normal healthy patient | No medical conditions |
| ASA 2 | Mild systemic disease, no functional limitation | Well-controlled hypertension, BMI 30-40 |
| ASA 3 | Severe systemic disease, functional limitation | COPD requiring inhaler, poorly controlled T2DM, Class II heart failure |
| ASA 4 | Severe systemic disease that is a constant threat to life | Recent MI, severe COPD on home O2 |
| ASA 5 | Not expected to survive without the operation | Ruptured AAA |
| ASA 6 | Brain-dead organ donor |
Pre-Operative Investigations
| Indication | Investigation |
|---|---|
| Any major surgery | FBC, U&E, clotting, group and save |
| Cardiac history | ECG, consider echo |
| Respiratory history or smoking | CXR, spirometry |
| Diabetes | HbA1c, blood glucose |
| Renal disease | U&E, eGFR, creatinine |
| Anticoagulation | INR (warfarin), TT/anti-Xa (DOAC) |
| Pregnancy risk | Beta-hCG (women of childbearing age) |
Medication Management Perioperatively
| Medication | Perioperative management |
|---|---|
| Warfarin | Stop 5 days before; bridge with LMWH if high thrombotic risk |
| DOACs (rivaroxaban, apixaban) | Stop 24-48 hours before (48 hours for renal impairment) |
| Aspirin | Continue in most cases; stop 7 days before if cardiothoracic surgery |
| Clopidogrel | Stop 7 days before elective surgery; discuss with cardiologist if stent |
| Metformin | Stop on day of surgery (contrast/renal risk); restart when eating/drinking and renal function stable |
| Insulin | Sliding scale (variable rate insulin infusion — VRIII) peri-operatively |
| ACE inhibitors/ARBs | Omit on morning of surgery (hypotension risk) |
| Steroids | Continue (adrenal suppression risk) — may need hydrocortisone cover |
| OCP/HRT | Stop 4 weeks before major surgery (VTE risk) |
Surgical Consent — Valid Consent Requirements
For consent to be valid, the patient must:
- 1Have capacity (Mental Capacity Act 2005)
- 2Be given adequate information (Montgomery standard — all material risks)
- 3Make their decision voluntarily (free from coercion)
The Montgomery Standard (2015)
Following the Supreme Court ruling in Montgomery v Lanarkshire, surgeons must disclose any risk that a reasonable patient would consider significant — not just risks that a reasonable doctor would disclose. This is a patient-centred, not doctor-centred, standard.
💎 Clinical Pearl
In an OSCE consent station: always ask what the patient already understands, explain the procedure in lay terms, cover the benefits, the material risks (including rare but serious ones), alternatives, and what happens if the procedure is not done. Check understanding. Give time to decide.
Consent Form Selection
| Form | Use |
|---|---|
| Form 1 | Adult with capacity for surgical/invasive procedure |
| Form 2 | Procedure requiring anaesthesia or sedation |
| Form 3 | Adult consenting where consciousness will not be lost |
| Form 4 | Adult lacking capacity (best interests decision, with documentation) |
WHO Surgical Safety Checklist
Three stages — Sign In, Time Out, Sign Out:
Sign In (before anaesthesia):
- Patient identity, procedure, site confirmed
- Site marked (if applicable)
- Anaesthetic machine and medication checks complete
- Pulse oximeter functioning
- Allergy/aspiration/difficult airway risk assessed
- Blood loss risk — IV access and fluids available
Time Out (before skin incision — team pause):
- Team introductions
- Patient identity, procedure, site reconfirmed
- Antibiotic prophylaxis given within 60 minutes
- Anticipated critical events (anaesthetic, surgical, nursing)
- Imaging available if required
Sign Out (before leaving theatre):
- Procedure name confirmed
- Swab, needle, instrument counts correct
- Specimen labelled
- Equipment issues to address
- Surgeon, anaesthetist, nurse key concerns for recovery
Post-Operative Complications — TIMELY
🧠 Mnemonic
TIMELY — post-operative complications by time:
- T (0-24 hours): haemorrhage, anaesthetic complications (aspiration, hypoxia), anaphylaxis
- I (1-3 days): infection (chest — atelectasis, SSI), ileus, DVT beginning
- M (3-7 days): wound infection peak, anastomotic leak (bowel surgery), pulmonary embolism
- E (over 1 week): PE, wound dehiscence, incisional hernia (longer term)
- L y (any time): urinary retention (especially post-spinal anaesthesia), pressure ulcers, AKI
- Y (systemic): electrolyte disturbance, drug errors, delirium
Common Post-Operative Problems
| Problem | Timing | Management |
|---|---|---|
| Reactionary haemorrhage | First 4 hours | Return to theatre vs surgical review |
| Atelectasis/chest infection | 24-72 hours | Physiotherapy, analgesia, early mobilisation |
| Urinary retention | 12-24 hours | Bladder scan — catheterisation if above 400 mL |
| Ileus | 2-5 days | NBM, IV fluids, NG tube if distended, treat cause |
| Wound infection | 5-7 days | Swab, antibiotics, consider opening wound |
| Anastomotic leak | 5-7 days | Sepsis, peritonism — CT, urgent surgical review |
| DVT/PE | Any time | LMWH/DOAC, treat precipitant |
Frequently Asked Questions
"What is the difference between a reactionary and secondary haemorrhage?"
Reactionary haemorrhage occurs within the first 4-6 hours after surgery, when vessels that were in spasm during hypotension dilate as blood pressure recovers. Secondary haemorrhage occurs 7-14 days post-operatively due to infection eroding vessel walls. Reactionary haemorrhage usually requires return to theatre; secondary haemorrhage requires infection treatment plus haemostasis.
"What is malignant hyperthermia?"
A rare but potentially fatal pharmacogenetic disorder triggered by volatile anaesthetic agents (halothane, sevoflurane, desflurane) or suxamethonium. Uncontrolled skeletal muscle calcium release causes extreme hypermetabolism — fever (often above 40 degrees C), tachycardia, rigidity, acidosis, hyperkalaemia, and rhabdomyolysis. Treatment: stop trigger agent immediately, dantrolene IV (muscle relaxant), active cooling, supportive care. Patients must be referred to a malignant hyperthermia unit for genetic testing and advised to wear medical alert ID.
"How do you manage a patient on warfarin who needs urgent surgery?"
For emergency surgery: reverse anticoagulation with IV vitamin K (5-10 mg) plus 4-factor prothrombin complex concentrate (PCC) or FFP. Target INR below 1.5. If surgery is semi-elective: stop warfarin 5 days before; bridge with LMWH if high thrombotic risk (mechanical heart valve, AF with CHA2DS2-VASc 5 or above); check INR day before surgery.
"What is suxamethonium apnoea?"
Suxamethonium is a depolarising neuromuscular blocking agent used for rapid sequence induction. It is metabolised by plasma cholinesterase. Patients with pseudocholinesterase deficiency (genetic variant) metabolise it very slowly — causing prolonged neuromuscular blockade and apnoea (minutes to hours). Managed with ventilation in ICU until the drug is metabolised. Genetic testing and family screening should follow.
"What post-operative VTE prophylaxis is standard in the UK?"
NICE recommends: risk assessment for all patients on admission using a validated tool (local trusts use Caprini or equivalent). Mechanical prophylaxis (anti-embolism stockings, pneumatic compression devices) for all patients at VTE risk. Pharmacological prophylaxis (LMWH) for moderate-high risk patients without contraindication (active bleeding, thrombocytopaenia, epidural in situ). Duration: 28 days post major orthopaedic surgery, 14 days for most abdominal surgery.
Related Posts
- Blood Results Interpretation OSCE — interpreting post-operative FBC, U&E, and CRP
- Medication Review OSCE — perioperative medication management and reconciliation
- Discharge Planning OSCE — planning safe post-operative discharge with appropriate follow-up