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SU10.1 | Principles of Perioperative Management — SDL Guide (Part 2)

Interpreting Perioperative Findings and the Deteriorating Patient

Perioperative management is not complete until you can interpret what the patient's observations are telling you and act, because postoperative complications announce themselves through subtle, recognisable patterns. Use the structured tools you already record. The postoperative observation chart and an early-warning score (such as the NEWS) flag deterioration before collapse: a rising heart rate, falling blood pressure, rising respiratory rate, falling oxygen saturation or falling urine output is the body signalling a problem. Read these against the timeline of common complications. Early postoperative bleeding presents as tachycardia and a narrowing pulse pressure before the blood pressure falls — remember that hypotension is a late sign of haemorrhage, so never be reassured by an early normal blood pressure. Postoperative fever has a classic time course — the 'five Ws': Wind (atelectasis/chest, days 1–2), Water (urinary infection, days 3–5), Wound (infection, days 5–7), Walking (deep-vein thrombosis, after day 5) and Wonder-drugs (drug reaction, any time). A breathless, tachycardic patient with desaturation after day 5 should raise pulmonary embolism. Low urine output (oliguria) usually signals hypovolaemia and demands assessment of fluid status before anything else. The interpretive principle is to combine the trend in the observations with the postoperative day and the operation performed to generate a focused differential, then escalate early — the deteriorating surgical patient rewards prompt senior review, not watchful waiting.

• Read the trend, not a single value: rising HR, falling BP, rising RR, falling SpO2 or urine output = deterioration (early-warning score).
• Bleeding: tachycardia + narrowed pulse pressure precede hypotension — hypotension is a LATE sign.
• Fever 'five Ws': Wind (chest, d1–2), Water (urine, d3–5), Wound (d5–7), Walking (DVT, >d5), Wonder-drugs (any time).
• Escalate early: combine trend + postoperative day + operation → focused differential → senior review.

Applying Perioperative Principles in Supervised Practice

The competency is demonstrated by applying these principles to real patients under supervision, and as a student you have a defined, useful role at every phase. Preoperatively, practise clerking the surgical patient: take the history and examine, assign a provisional ASA grade, list what needs optimising, check that valid consent has been taken and documented, confirm the fasting status against the 2-4-6-8 rule, and check that VTE and antibiotic prophylaxis have been prescribed. Present this to your supervising team as a structured 'fit for theatre' summary. Intraoperatively, observe and participate in the WHO Surgical Safety Checklist — notice who leads each of the three pause-points and what is confirmed at each; this is also where you practise the asepsis and assisting skills covered elsewhere. Postoperatively, join the ward round: read the observation chart and early-warning score, examine the wound and drains, review fluid balance and analgesia, and rehearse generating a differential for any abnormal observation against the postoperative day. Build the habit of escalating concerns early to a senior. Repeating this structured pathway across many patients is how the principles become an automatic, safe routine rather than a checklist you have to consciously recall — which is exactly the point of supervised practice before you carry the responsibility yourself.

Check Your Understanding

Consolidate the skill by walking the whole pathway in your mind. Start with the three phases — preoperative, intraoperative, postoperative — and the principle that most surgical harm is preventable and lives in this pathway. In the preoperative phase, risk-stratify with ASA physical status (remembering it grades the patient's disease, not the operation, and is not the Mallampati airway grade), optimise the patient, fast by the 2-4-6-8 rule, and prescribe VTE prophylaxis (mechanical plus LMWH where indicated) and antibiotic prophylaxis within 60 minutes before incision. In the intraoperative phase, run the WHO Surgical Safety Checklist at its three pause-points — Sign In before induction, Time Out before incision, Sign Out before leaving theatre. In the postoperative phase, deliver analgesia, fluids, early feeding and mobilisation, and surveillance, with ERAS spanning all three. Finally, interpret the deteriorating patient using the observation trend and the postoperative day. Self-test on four links: can you assign and justify an ASA grade; can you list the three WHO pause-points and when each is done; can you say why hypotension is a late sign of postoperative bleeding; and can you map the 'five Ws' of postoperative fever to their typical days? The questions below check exactly these.