haemorrhage, a large air bubble at the apex of the left ventricle, and bubbles in the right coronary artery. Transthoracic echocardiography showed numerous hyper-refringency areas in the cardiac left chambers, the left ventricular outflow tract, and in the ascending aorta consistent with a pulmonary venous air embolism which entered the left side of the heart (Fig. 1). No neurological changes were to be noted and brain CT scan and the subsequent brain MRI showed no abnormality. Within 1 h, the patient was put on hyperbaric oxygen therapy (HBOT). The HBOT session included a period of compression at 4 atmospheres absolute (ATA) for 10 min, followed by a treatment period at 100% oxygen and 1.9 ATA for 60 min, and then a decompression period of 15 min. Immediately after HBOT, the patient experienced a complete cardiac recovery with the normalization of CT scan, electric, and echocardiographic parameters. Troponin I was undetectable initially but had increased to 5 ng ml 21 6 h later, confirming an acute ST-elevation myocardial infarction (STEMI). The intensive care unit stay was uneventful and the patient was discharged home within 48 h.Pulmonary venous air embolism is a very rare event during transthoracic biopsy. 2 This complication may happen when the needle punctures an airway and a pulmonary vein inducing a parenchymal haemorrhage which promotes coughing. During coughing, elevated intrapulmonary pressure facilitates the passage of alveolar air into the pulmonary vein. 3 In this situation, a low air volume can induce a systemic air embolism with potential stroke or acute coronary ischaemia and fatal arrhythmias. 2 The diagnosis is not always obvious and must be considered in the presence of neurological or cardiac signs during the biopsy procedure. Besides CT scan, echocardiography appears to allow a rapid diagnosis. As for coronary angioplasty procedures during STEMI, 4 the reduction of gas volume in coronary arteries using HBOT should probably be carried out immediately. 3 Physicians should be aware of this life-threatening event which can also complicate radiofrequency ablation of metastatic lung tumours. 5 Emergency management protocol should be available in centres performing this kind of procedure.

This study did not confirm our hypothesis that short-current impulses (0.1 ms) make neurostimulation of peripheral nerves painless, by selectively depolarizing motor-neurons. Longer impulses (0.3 ms) shorten block performance time, probably by easier location of the nerves, but the clinical relevance of this finding is doubtful.

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