Peripheral air embolism

A 51-year-old man had venesection for haemochromatosis at his local clinic. After application of a tourniquet, a 14 gauge intravenous cannula was attached to intravenous tubing and a plastic collection bag, and inserted into a right antecubital fossa vein. Upon completion of the procedure, the tourniquet was released without previous clamping of the tubing system. The patient had a sudden gurgling sensation travelling up his arm, which was followed by severe central crushing chest pain with radiation to the jaw and left arm, severe dyspnoea, and left sided hemiparesis and dysphasia. Medical emergency services were contacted and the patient was transferred to hospital.On arrival he was hypoxic (oxygen saturation of 88% on room air). The left hemiplegia resolved within 15 minutes and the hypoxia, chest pain, and dyspnoea improved with application of high fl ow oxygen therapy. His initial ECG showed T-wave inversion inferiorly, which resolved within 12 hours of admission (appendix). Troponin I was raised at 0·14 μg/L (ref 0–0·08 μg/L) and fell to 0·08 6 hours later. Computed tomographic pulmonary angiography (CTPA) showed a fi lling defect in a subsegmental branch of the lingula (fi gure), which was suggestive of pul mon-ary embolism. Non-contrast CT brain scan was normal. 320-slice CT scan of the coronary arteries did not reveal any coronary abnormality but did show a patent foramen ovale. Transthoracic echocardiography with bubble study showed evidence of right-to-left shunting during both normal respiration and with Valsalva. Estimated baseline right heart pressures were normal. Transoesophageal echocardiogram confi rmed a patent foramen ovale and the passage of bubbles (appendix). The patient had an uncomplicated recovery and declined interventional closure of his patent foramen ovale.We postulate that air emboli were created when the tourniquet was released, resulting in pulmonary embolism with air emboli also crossing the patent foramen ovale to cause transient cerebral and myocardial ischaemia. Systemic air embolism and paradoxical air embolism through a cardiac defect have been well described and can occur in many types of vascular intervention.