Recognition

What “recognition” means in anaesthesia

• Recognition = noticing early signs of deterioration, confirming what is happening, and acting before harm occurs.
• It relies on: continuous monitoring, looking at the patient (not just the screen), and understanding what “normal for this patient” looks like.
• Most serious events have early warning signs (trends) before a crisis (e.g., rising airway pressure before hypoxia).
• Always ask: Is this real? Is it the patient, the machine, or the drugs?

Core approach: a simple recognition routine

• Use a repeated mental loop every few minutes: Patient → Monitors → Ventilator/circuit → Drugs/infusions → Surgical factors.
• Look for trends, not single numbers (e.g., falling BP over 5–10 minutes).
• Cross-check monitors: low SpO2 + low ETCO2 suggests different causes than low SpO2 + high ETCO2.
• If something changes, pause and re-check basics: airway, breathing, circulation, depth of anaesthesia.

Patient-first: what to look at (not just monitors)

• Colour: pallor/cyanosis; check lips/tongue (central cyanosis) not just fingers.
• Chest movement and work of breathing (if spontaneously breathing).
• Sweating, tearing, movement, grimacing: may indicate light anaesthesia or pain (but consider other causes).
• Bleeding: surgical field, suction, drapes, drains; look under the drapes if concerned.
• Urine output (longer cases): low output can be an early sign of hypovolaemia or poor perfusion.

Monitoring basics: what each monitor is “telling you”

• ECG: rate/rhythm; sudden bradycardia/tachycardia can be the first sign of hypoxia, bleeding, or drug effect.
• Blood pressure (NIBP/arterial): perfusion; watch trends and pulse pressure; check cuff position/size if readings odd.
• Pulse oximetry (SpO2): oxygenation; remember delay in desaturation and poor signal with low perfusion or movement.
• Capnography (ETCO2 waveform): ventilation + circulation + airway integrity; a “must-trust” monitor for airway events.
• Airway pressures/volumes: rising pressure suggests obstruction/bronchospasm/kink; falling pressure suggests leak/disconnection.
• Temperature: hypothermia is common and worsens bleeding, drug effects, and recovery; actively prevent and monitor.

Capnography recognition: patterns new starters should know

• Sudden loss of ETCO2 trace: think disconnection, oesophageal intubation, complete obstruction, or cardiac arrest (also check sampling line).
• Gradual fall in ETCO2: reduced cardiac output/bleeding, hyperventilation, or leak; interpret with BP and clinical context.
• Rising ETCO2: hypoventilation, increased CO2 production (e.g., shivering), rebreathing, or malignant hyperthermia (with other signs).
• “Shark-fin” waveform: bronchospasm or obstructed expiration; check wheeze, airway pressures, and consider treatment.
• Rebreathing (raised baseline): exhausted CO2 absorber, faulty valves, inadequate fresh gas flow in some systems.

Common first-time scenarios: what to recognise quickly

• Hypotension after induction: common; consider vasodilation (anaesthetic), hypovolaemia, anaphylaxis, arrhythmia, or bleeding; treat while investigating.
• Desaturation after intubation: check tube position, ventilation, circuit, bronchospasm, pneumothorax, aspiration; confirm with capnography and auscultation.
• High airway pressure: think kink/biting, secretions, bronchospasm, endobronchial intubation, pneumothorax; check circuit and patient.
• Unexpected movement/tachycardia/hypertension: consider light anaesthesia, pain, hypercarbia, hypoxia, full bladder, or drug error.
• Bradycardia: vagal stimulus (surgery), hypoxia, high spinal, drugs (opioids, beta-blockers), raised ICP; treat cause and support circulation.

Is it the patient, the machine, or the monitor?

• If a reading is surprising, check the patient and the trace quality before acting on a single number.
• Common artefacts: poor SpO2 signal (cold hand, movement), NIBP cuff wrong size, ECG interference, capnography sampling line kink/water.
• Do a quick equipment check: oxygen supply, circuit connections, APL valve, ventilator settings, vapouriser/agent delivery, suction.
• When in doubt, ventilate with 100% oxygen using a self-inflating bag and call for help early.

Escalation and teamwork: safe recognition behaviour

• Say concerns out loud early: “I’m worried about falling BP / loss of capnography.”
• Call for help early if: rapid deterioration, uncertainty, or no response to initial actions.
• Use a structured summary when calling: what happened, current vitals, what you’ve done, what you need.
• Agree roles: one person manages airway/ventilation, one manages drugs/IV access, one communicates with surgeons.

After recognition: confirm, treat, and document

• Confirm with at least two sources when possible (e.g., ETCO2 + chest rise + auscultation).
• Treat immediately reversible causes while continuing assessment (e.g., give vasopressor for severe hypotension while checking bleeding).
• Reassess response: did the intervention change the trend?
• Document key times, observations, actions, and response; hand over clearly to recovery/ICU if needed.