Postoperative breathlessness on day 3 after hip replacement

Leading diagnosis: pulmonary embolism (PE). This is a high pretest probability presentation: recent major orthopaedic surgery within three months, sudden-onset pleuritic chest pain, breathlessness, tachycardia of 118, hypoxia of 89%, and hypoperfusion (clamminess, BP 104/66). The absence of calf pain does not argue against PE - most PEs arise from proximal or pelvic veins and many patients have no leg symptoms. His BMI and hypertension add to baseline risk.

Other possibilities to weigh:

• Pneumonia: possible but less likely - he is afebrile at 37.4°C with no cough or sputum, and the onset was sudden rather than progressive.
• Pneumothorax: sudden pleuritic pain and hypoxia fit, but there is no risk factor and no unilateral chest signs described; still worth excluding on imaging.
• Acute coronary syndrome: tachycardia and clamminess fit, but the pain is pleuritic and the presentation is dominated by breathlessness; an ECG is still needed.
• Aspiration or opioid-related hypoventilation: oxycodone could contribute to hypoventilation but would not explain pleuritic pain or tachycardia of this degree.
• Heart failure or arrhythmia: possible given hypertension, but the abrupt onset and pleuritic pain favour PE.
• Wound haematoma or bleeding: his pallor and clamminess could reflect bleeding, particularly with enoxaparin; check the wound and consider haemoglobin.

Weighting: PE is the diagnosis to act on. The combination of tachycardia, hypoxia, and hypoperfusion suggests intermediate-to-high risk PE, and the clinical priority is stabilisation and urgent transfer, not outpatient investigation.

Reasoning: The exam is testing whether you recognise a time-critical diagnosis in a primary care setting and whether you can reason with a differential rather than anchor on one possibility.

Immediate actions:

1. Call an ambulance immediately - this is a medical emergency. Do not send him for outpatient imaging or arrange a routine review.
2. Position and oxygen: sit him upright, give high-flow oxygen titrated to target saturation (94–98%), and apply continuous pulse oximetry if available.
3. IV access if the practice can do so, and cardiac monitoring if available; attach the defibrillator.
4. Do not give aspirin on the assumption of ACS without clearer evidence - the picture favours PE, and antiplatelet therapy could worsen bleeding risk if there is a haemorrhagic component. Follow local protocols.
5. Check capillary glucose, repeat observations, and examine for unilateral leg swelling, chest signs, and wound haematoma while awaiting transport.
6. Record an ECG if it can be done without delaying transfer - it helps the receiving team and may show sinus tachycardia, right heart strain, or an alternative diagnosis.
7. Reassure him and his wife, explain what is happening, and keep them informed.

Handover (structured, e.g. ISBAR):

• Identify: Trevor Hall, 71, three days post total hip replacement.
• Situation: Sudden breathlessness and pleuritic chest pain two hours ago; hypoxic at 89% on room air, tachycardic at 118, BP 104/66, clammy.
• Background: Hypertension, BMI 33, on enoxaparin 40 mg daily, oxycodone, paracetamol.
• Assessment: Suspected pulmonary embolism with haemodynamic compromise; differential includes pneumonia, pneumothorax, ACS, and bleeding.
• Recommendation: Requesting urgent paramedic assessment and transfer for CT pulmonary angiography and anticoagulation; he is on prophylactic enoxaparin only; observations and ECG findings included.

Reasoning: The judgement is about escalation and safe handover under time pressure, and about not being distracted into outpatient workup when the patient is unstable.

Responding to the wife:

• Acknowledge her fear and the shock of the sudden change.
• Explain that major hip surgery is a recognised risk factor for blood clots in the legs travelling to the lungs, because of immobility, the surgery itself, and reduced mobility afterwards. This is why he was given a preventive dose of blood thinner.
• Explain honestly that preventive doses reduce but do not eliminate the risk; they are lower than treatment doses and are designed for prophylaxis, not guaranteed prevention. Avoid implying fault or guaranteeing outcomes.
• Explain what happens next: the hospital team will confirm the diagnosis, likely with a CT pulmonary angiogram, and if confirmed he will need treatment-dose anticoagulation, monitoring, and follow-up.
• Avoid speculation about blame or prognosis beyond what is known; offer to speak again once he is assessed.

Follow-up arrangements:

• Contact the practice once he is admitted to confirm his location and status.
• Once discharged, arrange early review: wound check, medication reconciliation (especially anticoagulation duration and interactions with oxycodone and any NSAIDs), and monitoring of renal function and bleeding risk.
• Discuss the duration of anticoagulation with the treating team - provocation by major surgery usually means a defined period, but this is their decision.
• Arrange review of his opioid use, mobility, and VTE risk for future procedures; document the event prominently in his record.
• Debrief and support the wife, and offer a follow-up conversation when she is less distressed.

Reasoning: The exam tests communication under uncertainty, avoiding both defensiveness and false reassurance, and closing the loop with concrete follow-up rather than leaving the family without a plan.