A 65 year old male with a past history of ischaemic heart disease is admitted to the ICU after a motorcycle crash having sustained long bone fractures of the lower limbs. He has no head, chest or abdominal injuries. Prior to surgery, his GCS was 15 and SpO2 was 98% on 4l oxygen via Hudson mask with a normal chest X-Ray. He required prolonged operative fixation of his fractures and that was complicated by significant blood loss. Intra-operatively, he also developed increasing oxygen requirement. On arrival in ICU, his most recent arterial blood gas on an FiO2 of 0.7 shows a PaO2 55 mmHg.
- 28.1. List the differential diagnoses for his respiratory failure.
- 28.2. What assessment and investigations would you perform to help establish the diagnosis?
Answer and interpretation
28.1. List the differential diagnoses for his respiratory failure.
- Iatrogenic fluid volume overload due to blood product/resuscitation fluid
- Atelectasis/Collapse/sputum plugging
- Unrecognised pulmonary contusions
- Unrecognised pneumothorax – Mech vent, line insertion
- Aspiration at time of MBA or at intubation
- Endobronchial intubation
- Transfusion related acute lung injury (TRALI)
- Cardiogenic pulmonary oedema/myocardial event
- Fat embolism syndrome
28.2. What assessment and investigations would you perform to help establish the diagnosis?
- Ensure adequate tertiary survey
- Detailed respiratory examination
- Review fluid balance and urine output
- Evidence of generalised allergic reaction
- FBE – Hb, WCC, eosinophilia
- Coags – ongoing coagulaopathy,
- CXR – infiltrates, ETT position, hardware, PTx, pleural effusions
- Cardiac enzymes – TnI
- ECG – ischaemic changes, arrhythmia, R heart strain
- Echocardiogram – if suspect cardiogenic component, assess LVF, or RVF for PE
- CTPA – early for PE but possible if pt delayed in ED Bronchoscopy – if evidence of localised collapse or unexplained infiltrates