Persistent Hypoxemia Despite Intervention
Invasively monitored patients in ICU following cardiothoracic surgery may suffer from hypoxaemia for a multitude of reasons such as pre-morbid state, intra-operative, post-operative and procedural complications. A plain chest radiograph would identify common treatable conditions and complications such as pneumothorax, haemothorax, lung collapse, or pulmonary oedema. Approaching the chest radiograph in a logical fashion, including assessment of the lungs, mediastinum, soft tissues, thoracic cage and all visible artifacts (lines and tubes) is likely to elucidate most of the possible causes of hypoxaemia. CT is used as a secondary test when the diagnosis is not clear or cannot be visualised on plain film. The chest x-ray should be evaluated thoroughly, taking into consideration the position of the patient and the procedures recently undertaken, and reviewed in series with previous imaging. This chapter describes and illustrates common and important causes of hypoxia in this group of post-interventional patients.