|Year : 2016 | Volume
| Issue : 2 | Page : 76-78
To air is human, to liberate is divine!
Prakash Chand1, Neeraj Pandit1, Nirlep Gajiwala2, Ashok Thakkar2
1 Department of Cardiology, Dr. Ram Manohar Lohia Hospital and Postgraduate Institute of Medical Education and Research, New Delhi, India
2 Department of Clinical Trials, Sahajanand Medical Technologies Pvt. Ltd., Surat, Gujarat, India
|Date of Web Publication||6-Jun-2016|
Department of Cardiology, Dr. Ram Manohar Lohia Hospital and Postgraduate Institute of Medical Education and Research, New Delhi - 110 001
Source of Support: None, Conflict of Interest: None
Coronary artery air embolization is a rare complication of cardiac catheterization that leads to catastrophic consequences within seconds after an introduction of air bubbles in the coronary circulation. Rapid and aggressive management is essential to ensure the best chance of recovery in such cases. Here, we report an unusual occurrence of large air embolization during elective percutaneous transluminal coronary angioplasty in a 41-year-old male patient. The patient experienced sudden severe retrosternal chest pain, followed by loss of consciousness, hypotension, flattening of aortic pressure curve, and severe bradycardia. Immediate attempts were made to remove the air embolus by performing continuous saline flush through a guiding catheter and using other supportive resuscitation measures. The attempts were successful, which ultimately resulted in relieving patient's symptoms and offering an uneventful recovery.
Keywords: Air embolism, cardiac catheterization, intraoperative complication
|How to cite this article:|
Chand P, Pandit N, Gajiwala N, Thakkar A. To air is human, to liberate is divine!. Heart India 2016;4:76-8
| Introduction|| |
Coronary air embolism, resulting from iatrogenic introduction of air bubbles into coronary circulation, is a rare complication of cardiac catheterization, with a reported incidence of 0.1-0.3%.  Consequences of this complication depends on the amount of air that is introduced in the coronary vessels, and may range from clinically insignificant events to episodes of angina, myocardial infarction, cardiac arrest, and death.  Herein, we present a case of large air embolization during elective percutaneous transluminal coronary angioplasty (PTCA), with an episode of acute coronary event. Owing to the rapid and effective management measures, removal of coronary air embolism was successful and subsequent adverse events were prevented.
| Case report|| |
A 41-year-old male, a laborer by occupation, presented to our hospital with complaint of angina on exertion (Class III) for the past 1 month. The patient was nondiabetic, nonhypertensive, and chronic smoker. He was a known case of coronary artery disease and had suffered inferior-wall myocardial infarction. He had, elsewhere, received a bare-metal stent to the left circumflex coronary artery (LCX) about 4 years ago. On reviewing the history, patient disclosed that he had continued smoking and did not take prescribed anti-ischemic drugs for the past 2 years.
Echocardiogram of the patient revealed hypokinesia in inferoposterior wall, with 45% left-ventricular ejection fraction. The diagnostic coronary angiogram revealed 100% in-stent restenosis (ISR) to LCX stent while left anterior descending artery (LAD) and right coronary artery were normal [Figure 1]. The patient was advised for PTCA to LCX-ISR lesion and was encouraged to quit smoking and take anti-ischemic medications as prescribed.
|Figure 1: Stent in left circumflex coronary artery showing 100% in-stent restenosis|
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On the decided day, PTCA was performed through right femoral access. A bolus of unfractionated heparin (5000 units) was given intravenously. After the engagement of guiding catheter to the left main coronary artery, the LCX-ISR lesion was crossed with 0.014" guide wire. Then, the lesion was predilated with 2.5 mm × 12 mm Sprinter Legend balloon (Medtronic, Ireland). Contrast injection revealed dilated LCX segment with good distal flow, but the patient complained of sudden severe retrosternal chest pain, which was followed by loss of consciousness, hypotension, flattening of aortic pressure curve, and severe bradycardia. We immediately reviewed cineangiographic films which revealed inadvertent entry of multiple large air bubbles in the vessels, indicating obstruction of blood flow in both, LAD and LCX, arteries [Figure 2] and [Figure 3]. Immediately, multiple boluses of saline flush were forcefully injected through the catheter to dissipate air embolus. Simultaneously, the patient was treated with implantation of temporary transvenous pacemaker at the right-ventricular apex, along with constant supportive measures in the form of cardiopulmonary resuscitation, hyperbaric oxygen, and administration of dopamine infusion, atropine intravenous (IV), and adrenaline IV. The prompt measures we took were successful as the symptoms of the patient disappeared rapidly. After 5-10 min, the patient regained consciousness. Once the patient's hemodynamic status was stabilized, we confirmed the disappearance of air embolism and sufficient blood flow in LAD and LCX arteries [Figure 4]. After discussing with the cath lab team and patient's relatives, a decision was made to postpone the PTCA procedure. The patient was managed conservatively for 5 days in the hospital. He remained asymptomatic.
|Figure 2: Contrast injection revealed inadvertent entry of large air bubbles in left anterior descending and left circumflex arteries immediately after balloon predilatation|
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|Figure 3: Air embolism causing pulsatile coronary blood flow and abrupt cessation in the left anterior descending artery|
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|Figure 4: Continuous saline flush led to disappearance of air embolism and sufficient blood flow in left anterior descending and left circumflex arteries; temporary pacemaker was implanted to manage bradycardia|
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After about 45 days, the patient received 2.75 mm × 24 mm drug-eluting stent in the LCX-ISR lesion. The procedure was performed with precautions and was uneventful. After an overnight stay, the patient was discharged in stable condition with optimized medical therapy.
| Discussion|| |
In this report, we present a rare event of air embolism, which occurred only this time among the last 1000 PTCAs performed at our institution. In our patient, the air embolus was large enough to obstruct coronary blood flow, which led to symptoms of angina pectoris and cardiac arrest.
Khan et al. have reported an interesting finding that events of coronary air embolism were more frequent during PTCA than during diagnostic catheterization.  The possible causes of air embolization during PTCA are inadequate aspiration of guiding catheters, rupture of balloon during high inflation, the insinuation of air into catheters during balloon catheter or guide wire introduction and/or withdrawal, and movement of air from catheter to coronary system during intracoronary medication.  The cause of air embolization in our patient might be inadequate aspiration of guiding catheter; however, the exact mechanism could not be identified.
Air embolism during cardiac catheterization can be prevented by careful aspiration of catheters, vigilant flushing of coronary equipment, and fluoroscopic monitoring of guiding catheter advancement. However, if the condition occurs, the primary goal of management is to protect and maintain vital functions by providing hemodynamic support and promoting dissipation of air bubbles. Rapid and aggressive treatment is required to ensure the best chance of recovery.  An evidence-based management option for air embolization remains uncertain due to the rarity of such events.  Treatment may comprise:
- Hyperbaric oxygen therapy: To minimize ischemia and to establish a diffusion gradient that encourages significant reduction in the size of air bubble ,
- Intra-aortic balloon pumping and inotropic agents: To offer transient elevation in arterial blood pressure ,
- Forceful injection of saline or contrast medium: To allow fragmentation and dispersal of air bubble ,
- Rapid cardiopulmonary resuscitation: To maintain cardiac output and for forceful removal of air from the coronary vessels after assisting the fragmentation of large air bubbles 
- Guide wire: To disrupt distal air bubbles ,
- Thrombectomy catheters or over-the-wire balloon catheters: To achieve direct air bubble extraction ,
- Other supportive measures: Intracoronary adenosine, nitroprusside, and calcium-channel blockers to treat vasospasm and to improve coronary flow; atropine, adrenaline, dopamine to manage bradycardia. ,
Few cases of successful management of coronary air embolism using hyperbaric oxygen therapy,  cardiopulmonary resuscitation,  forceful injection of contrast medium,  intra-aortic balloon pumping,  or thrombectomy catheter, , are recently reported. In our patient, we chose forceful saline injection through the catheter to propel air bubbles to the terminal portion of the coronary artery. In addition to supportive measures such as cardiopulmonary resuscitation and hyperbaric oxygen, a temporary pacemaker was implanted to treat severe bradycardia. We strongly believe that our patient had recovered successfully due to early detection and rapid management of air embolism. To the best of our knowledge, the present case is a rare Indian report of successful management of coronary air embolism in cath lab. We are of the opinion that greater awareness about its etiology, preventive measures, and decisive management options will lead to safer practice of PTCA.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]