Systemic air embolism during lung biopsy

Abstract

Editor'Percutaneous biopsy guided by computed tomographic (CT) scan is commonly used for the diagnosis of pulmonary lesions.1Tomiyama N Yasuhara Y Nakajima Y et al.CT-guided needle biopsy of lung lesions: a survey of severe complication based on 9783 biopsies in Japan.Eur J Radiol. 2006; 59: 60-64Abstract Full Text Full Text PDF PubMed Scopus (361) Google Scholar The occurrence of a systemic air embolism is a rare but potentially lethal complication.2Klein JS Zarka MA Transthoracic needle biopsy.Radiol Clin North Am. 2000; 38 (vii): 235-266Abstract Full Text Full Text PDF PubMed Scopus (96) Google Scholar A 57-yr-old man was admitted in our hospital for the investigation of three pulmonary lesions recently found on a chest CT scan. He had a rectal cancer 3 yr previously treated with radiotherapy, neoadjuvant chemotherapy, and an anterior resection. No comorbidity was to be noted. The patient was undergoing a left lung biopsy. The patient was placed prone and a coaxial biopsy system with a core biopsy needle was used. After local anaesthesia, the percutaneous biopsy was performed with CT scan-fluoroscopic guidance at the left lower lobe of the lung by an experienced radiologist. During the procedure, the patient suddenly presented with haemoptysis, cough, and acute chest pain. Clinical examination retrieved hypotension (systolic arterial pressure <60 mm Hg) and a severe bradycardia (<50 beats min−1). The procedure was immediately stopped. The patient was placed in the Trendelenburg position. He received i.v. saline solution and high-concentration oxygen by a facemask. The ECG showed significant elevation of ST segment at the posterior (II, III, aVF) and anterior (V1, V2, V3) leads. An immediate chest CT scan showed localized parenchymal 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−1 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.2Klein JS Zarka MA Transthoracic needle biopsy.Radiol Clin North Am. 2000; 38 (vii): 235-266Abstract Full Text Full Text PDF PubMed Scopus (96) Google Scholar 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.3Hiraki T Fujiwara H Sakurai J et al.Nonfatal systemic air embolism complicating percutaneous CT-guided transthoracic needle biopsy: four cases from a single institution.Chest. 2007; 132: 684-690Abstract Full Text Full Text PDF PubMed Scopus (115) Google Scholar In this situation, a low air volume can induce a systemic air embolism with potential stroke or acute coronary ischaemia and fatal arrhythmias.2Klein JS Zarka MA Transthoracic needle biopsy.Radiol Clin North Am. 2000; 38 (vii): 235-266Abstract Full Text Full Text PDF PubMed Scopus (96) Google Scholar 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,4White HD Chew DP Acute myocardial infarction.Lancet. 2008; 372: 570-584Abstract Full Text Full Text PDF PubMed Scopus (542) Google Scholar the reduction of gas volume in coronary arteries using HBOT should probably be carried out immediately.3Hiraki T Fujiwara H Sakurai J et al.Nonfatal systemic air embolism complicating percutaneous CT-guided transthoracic needle biopsy: four cases from a single institution.Chest. 2007; 132: 684-690Abstract Full Text Full Text PDF PubMed Scopus (115) Google Scholar Physicians should be aware of this life-threatening event which can also complicate radiofrequency ablation of metastatic lung tumours.5Burgoyne LL Pereiras LA Laningham F Shearer JR Bikhazi GB Hoffer FA Near-fatal acute bronchovenous fistula in a child undergoing radiofrequency ablation of a metastatic lung tumor.Paediatr Anaesth. 2008; 18: 1131-1133Crossref PubMed Scopus (7) Google Scholar Emergency management protocol should be available in centres performing this kind of procedure. None declared.