Paradoxical air embolism from a central venous catheter

Abstract

Editor—A 66-yr-old female, non-smoking patient without relevant comorbidities underwent an uneventful right nephrectomy for renal cell carcinoma. Before surgery, a triple-lumen 7 F catheter was placed in the right internal jugular vein for perioperative haemodynamic management. The following post-surgical period was unremarkable. On postoperative day 4 before removal, the caps of the central venous catheter were disconnected with the patient sitting in an upright position. Immediately after disconnection of the caps and removal of the catheter, the patient lost consciousness, then became cardiopulmonary unstable followed by cardiac arrest. Immediately after successful cardiopulmonary resuscitation, the initial ECG, which was performed upon arrival on the ICU, showed significant ST-segment elevation in leads II, III, aVF and depression in aVL, consistent with acute posterior myocardial infarction. A coronary angiogram was performed, but no evidence of coronary artery occlusion was found. Two hours after the initial cardiac arrest, the ST-segment had returned to normal. Analgosedation (propofol and fentanyl), which was initiated after cardiopulmonary resuscitation, was terminated. However, as the patient regained consciousness 3 h after removal of the central line, she had a complete left-sided hemiplegia. An emergency CT of the brain demonstrated no specific abnormality. Given the direct chronological coincidence, cerebral air embolism was suspected as the most likely reason for the focal neurological deficit. Treatment was symptomatic, including administration of oxygen 100% (because of air embolus), i.v. fluids, serum glucose <6.6 mmol litre−1, systolic arterial pressure between 110 and 190 mm Hg, normocapnia, and early mobilization of the patient. In order to explore the route of air into the cerebral and coronary vasculature, a transoesophageal echocardiogram was performed. A large patent foramen ovale measuring 1.5×1 cm could be identified, suggestive of paradoxical air embolism. A bubble study demonstrated instant and massive pass from the right to left chambers (Fig. 1). Fortunately, recovery of the patient was remarkably fast; on re-examination 4 h later, motor strength of the left arm and leg had almost returned to normal, and cardiopulmonary situation remained unchanged. After an uneventful 3 days, the patient was discharged from the hospital without any neurological or cardiac residual symptoms. Venous air emboli can paradoxically enter the arterial circulation through a patent foramen ovale and cause major harm.1Heckmann JG Lang CJG Kindler K Huk W Erbguth FJ Neundörfer B Neurologic manifestations of cerebral air embolism as a complication of central venous catheterization.Crit Care Med. 2000; 28: 1621-1625Crossref PubMed Scopus (187) Google Scholar, 2Novack V Shefer A Almog Y Coronary air embolism after removal of central venous catheter.Heart. 2006; 92: 39Crossref PubMed Scopus (3) Google Scholar, 3Fathi AR Eshtehardi P Meier B Patent foramen ovale and neurosurgery in sitting position: a systematic review.Br J Anaesth. 2009; 102: 588-596Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar Patent foramen ovale can be found in at least 25% of the general population.4Hagen PT Scholz DG Edwards WD Incidence and size of patent foramen ovale during the first 10 decades of life: an autopsy study of 965 normal hearts.Mayo Clin Proc. 1984; 59: 17-20Abstract Full Text Full Text PDF PubMed Scopus (2030) Google Scholar The patent foramen ovale is usually functionally closed, unless the right atrial pressure exceeds the left atrial pressure, allowing right-to-left shunting. In the case reported, significant right-to-left shunting was observed as most likely a significant amount of air passed from the right over to the left ventricle, presumably because left atrial pressure was low because of postoperative dehydration, systemic hypotension, and an upright position. This case presents the need for awareness of this rare but potentially life-threatening complication. Furthermore, sudden neurological or cardiac events after manipulation of a central venous line should call attention to a possible paradoxical air embolus. No specific treatment is available, but administration of oxygen 100% and i.v. fluids seems prudent.5Doostan DK Steffenson SL Snoey ER Cerebral and coronary air embolism: an intradepartmental suicide attempt.J Emerg Med. 2003; 25: 29-34Abstract Full Text Full Text PDF PubMed Scopus (6) Google Scholar To prevent such events, any manipulation of central venous lines should be undertaken in the supine position while the spontaneous breathing patient is exhaling.6Turnage WS Harper JV Venous air embolism occurring after removal of a central venous catheter.Anesth Analg. 1991; 72: 559-560Crossref PubMed Scopus (27) Google Scholar However, even with severe neurological and cardiac effects, outcome may not be fatal. Download .zip (.0 MB) Help with zip files Download .zip (.0 MB) Help with zip files