Venous air embolism may be difficult to diagnose and requires a high level of suspicion because it may mimic other conditions [1] [2]. Patients have an invasive procedure in the recent history and present with respiratory and neurological symptoms, such as dyspnea, tachypnea, gasps [3] and cough, as well as seizures, vertigo, syncope, agitation, ataxia and sense of "impeding doom." These signs have an acute character. The neurological situation rapidly progresses in severe cases from an altered mental status to focal deficits and coma. Victims may also complain about chest pain and impaired vision and speech. However, this ailment is not always iatrogenic and may be encountered after hydrogen peroxide ingestion, scuba diving, decompression or penetrating trauma.

Severe cases, where the amount of air that enters circulation, as well as its entrance rate are high, present with cardiovascular collapse and organ failure [4]. The position of the body during the event is also important: if air has entered the venous system while sitting, it will reach the cerebral circulation, while a recumbent position favors gas entrance in the pulmonary circulation, causing pulmonary hypertension, release of endothelin-1 from the pulmonary vascular endothelium [5], right ventricle decompensation, diminished ventricular preload and systemic hypotension [6]. An arterio-venous or cardiac shunt, such as an atrial or ventricular septal defect or patent foramen ovale makes arterial embolization possible, with consequences like a stroke or myocardial infarction [7].

• Dyspnea

  This exam offers additional information, related to heart structure and function, the presence and severity of pulmonary hypertension, thus being useful in excluding other causes of acute dyspnea and chest pain. [symptoma.com]

  At the end of the examination, when the patient got down from the examining table, he had acute dyspnea, weakness of the arms and legs, and dizziness. He did not lose consciousness. [nejm.org]

  Pulmonary symptoms in awake patients include dyspnea, coughing, lightheadedness, and chest pain. As the patient gasps for air resulting from dyspnea, there can be a further reduction in intrathoracic pressure and hence more air entrainment. [mhmedical.com]

  She was seen in the hospital with a one-year history of worsening exertional dyspnea (NYHA grade III), deteriorating exercise tolerance and episodic paroxysmal nocturnal dyspnea. [omicsonline.org]

  […] introduced air, as well as patient’s position Sitting position – venous emboli in cerebral circulation Seizure, coma Supine position Impaired right ventricular function (decreased cardiac output and hypotension) Microemboli to pulmonary vasculature (dyspnea [renalandurologynews.com]

• Painful Cough

  The symptoms that may be seen include : Difficulty breathing Dizziness or lightheadedness Chest pain Cough Nausea Occasional gasping Anxiety Disorientation In addition, there are various signs showing disruption in the heart activity, breathing, brain [healthhype.com]

• Chest Pain

  This exam offers additional information, related to heart structure and function, the presence and severity of pulmonary hypertension, thus being useful in excluding other causes of acute dyspnea and chest pain. [symptoma.com]

  Introduction A CTPA was performed on a 45 year old male who presented with central chest pain and a past history of PE and DVT. Results No PE detected. [wikiradiography.net]

  Pain (see Chest Pain, [[Chest Pain]]): due to myocardial ischemia Crepitus over Superficial Vessels : observed rarely in setting of massive air embolus Hypotension (see Hypotension, [[Hypotension]]) Mill Wheel Murmur : churning sound heard throughout [mdnxs.com]

  Commonly reported clinical manifestations include sudden dyspnea, chest pain, hypotension and/or convulsions 4. Etiology They can arise from both iatrogenic and non-iatrogenic causes. [radiopaedia.org]

  Pulmonary symptoms in awake patients include dyspnea, coughing, lightheadedness, and chest pain. As the patient gasps for air resulting from dyspnea, there can be a further reduction in intrathoracic pressure and hence more air entrainment. [mhmedical.com]

• Decompression Sickness

  In cases of decompression sickness, the pressure forces the bubbles of nitrogen to dissolve back into the bloodstream. [nhs.uk]

  Air embolism and decompression sickness. In Rippe, 3rd ed, 1996 � Charles Gomersall July 1999 [aic.cuhk.edu.hk]

  A pulmonary barotrauma is usually obvious and may present quite differently from decompression sickness. [ citation needed ] Decompression sickness (DCS): Inert gas bubbles form in the bloodstream if the gas dissolved in the blood under pressure during [en.wikipedia.org]

  sickness (neurologic impairment from nitrogen bubbles) was made by DAN for the four years 1987-1990 (Corson 1991). 1, record 1, English, - arterial%20gas%20embolism Record 1, French Record 1, Domaine(s) Appareil respiratoire Plongée sous-marine (Sports [btb.termiumplus.gc.ca]

  Here it is known as decompression sickness, or more commonly as the bends. However, most instances of a venous air embolism occur within the hospital environment from catheterization or surgical procedures where a person is sitting upright. [healthitalk.com]

• Tachycardia

  These signs included a decrease in arterial haemoglobin oxygen saturation as measured by pulse oximetry, decreased end-tidal carbon dioxide level and tachycardia. [ncbi.nlm.nih.gov]

  EKG (nonspecific): ST elevation, tachyarrhythmias Head CT: If neurologic deficits The presence of acute hypoxia, tachycardia and/or hypotension in a relevant clinical scenario is concerning for air embolism. [clinicaladvisor.com]

  The electrocardiogram may show right ventricular strain pattern, tachycardia, and tachyarrhythmia. A thoracic X-ray can identify a dilated pulmonary artery, the presence of pulmonary edema or that of gas in the pulmonary vascular system. [symptoma.com]

• Dizziness

  At the end of the examination, when the patient got down from the examining table, he had acute dyspnea, weakness of the arms and legs, and dizziness. He did not lose consciousness. [nejm.org]

  Symptoms of an air or gas embolism after diving Symptoms of an air or gas embolism after diving include: joint or muscle pain low blood pressure, which may cause dizziness an irregular heartbeat breathlessness and fast breathing blurred vision chest pain [nhs.uk]

  The symptoms that may be seen include : Difficulty breathing Dizziness or lightheadedness Chest pain Cough Nausea Occasional gasping Anxiety Disorientation In addition, there are various signs showing disruption in the heart activity, breathing, brain [healthhype.com]

  /Lightheadedness (see Dizziness, [[Dizziness]]) Focal Neurologic Deficits Headache (see Headache, [[Headache]]) Obtundation/Coma (see Obtundation-Coma, [[Obtundation-Coma]]) Seizures (see Seizures, [[Seizures]]) Vision Loss (see Vision Loss, [[Vision [mdnxs.com]

Blood workup should include an arterial blood gas assessment, demonstrating hypoxemia and hypercapnia. Metabolic acidosis can also be encountered, as can respiratory alkalosis. The presence of air in the right ventricle and outflow tract can be determined by clinical examination due to the presence of a specific murmur audible over the precordial area and compared to a moving mill wheel and by transesophageal echocardiography [8]. This exam offers additional information, related to heart structure and function, the presence and severity of pulmonary hypertension, thus being useful in excluding other causes of acute dyspnea and chest pain [9]. Doppler echography is useful in the direct detection of the air embolus [10] and it can be performed in various territories [3]. Computed tomography and magnetic resonance imaging offer the same information. The electrocardiogram may show right ventricular strain pattern, tachycardia, and tachyarrhythmia. A thoracic X-ray can identify a dilated pulmonary artery, the presence of pulmonary edema or that of gas in the pulmonary vascular system.

The most sensitive, although not the widely available method for venous air embolism detection remains the end-tidal nitrogen monitoring. Despite its sensitivity, this method’s use is limited by hypotension. End-tidal carbon dioxide monitorization is less specific.

If a pulmonary artery catheter is in place, it will show the abrupt increase of the pulmonary pressure. In cases where the patient has a central venous catheter, air can be aspirated through its lumen, making the diagnosis clear.

• Pulmonary Infiltrate

  Despite immediate treatment the patient's gas exchange progressively worsened during surgery and a chest X-ray showed extensive bilateral pulmonary infiltrates. [ncbi.nlm.nih.gov]

Early detection together with aggressive treatment is the only way in the management of intraoperative venous air embolism. [ncbi.nlm.nih.gov]

The clinical significance and prognosis in this setting requires further investigation. [ncbi.nlm.nih.gov]

While the chapters discuss definitions, pathophysiology, clinical course, complications, and prognosis, the primary emphasis is devoted to patient management. [books.google.com]

Prognosis The prognosis in air embolism is largely dependent on the rate and volume of air entrained into the circulation and the patient’s underlying comorbidities. Overall mortality ranges from 50%-80%. [clinicaladvisor.com]

Immediate HBOT, once VAE is diagnosed, is recommended; however, prognosis may still be good if therapy is initiated beyond 6 hours of event. [emedicine.medscape.com]

Treatment and prognosis The risk of death is affected by both the amount of gas and the speed of introduction; the minimum lethal volume and injection rate in humans are thought to be around 300-500 mL and 100 mL/sec, respectively 4. [radiopaedia.org]

Etiology They can arise from both iatrogenic and non-iatrogenic causes. Iatrogenic causes Venous gas embolism is a well-known complication of thoracic trauma, surgery, and a variety of diagnostic and therapeutic procedures. [radiopaedia.org]

Brandner P, Neis KJ, Ehmer C: The etiology, frequency, and prevention of gas embolism during CO(2) hysteroscopy. J Am Assoc Gynecol Laparosc 1999;6:421-428. [karger.com]

The etiology, frequency, and prevention of gas embolism during CO2 hysteroscopy. J Am Assoc Gynecol Laparosc 1999; 6:421-8. [PubMed] Leibowitz D, Benshalom N, Kaganov Y, Rott D, Hurwitz A, HamaniY. [apicareonline.com]

The fall was no more than 1-6 mmHg even where mean arterial pressure was deliberately decreased by 43%. [16] Similar observations have also been reported during hypotension of various etiologies. [15] We observed 22% incidence of VAE in the present series [neurologyindia.com]

Epidemiology Incidence : increasing frequency (due to increasing risk factors) Etiology Cardiothoracic Surgery/Procedures Cardiopulmonary Bypass (see Cardiopulmonary Bypass, [[Cardiopulmonary Bypass]]): venous air embolism Fine Needle Aspiration (FNA) [mdnxs.com]

Dog model: 0.5 mL/kg/min led to cardiorespiratory failure ( Adornato 1978 ) Human data: 200-500 mL air introduced at 100 mL/sec was acutely fatal (~3–5 mL/kg), other estimates suggest < 50 mL of air ( O’Dowd 2013, Feil 2015 ) Epidemiology Central lines [coreem.net]

Epidemiology Occurs particularly in patients undergoing medical or surgical procedures, particularly those in a sitting position (neurosurgical) or where vasculature is exposed to air or manipulated or requiring air insufflation (laparoscopic procedures [clinicaladvisor.com]

[ edit ] In terms of the epidemiology of air embolisms one finds that the intra-operative period to have the highest incidence. [en.wikipedia.org]

Epidemiology Incidence : increasing frequency (due to increasing risk factors) Etiology Cardiothoracic Surgery/Procedures Cardiopulmonary Bypass (see Cardiopulmonary Bypass, [[Cardiopulmonary Bypass]]): venous air embolism Fine Needle Aspiration (FNA) [mdnxs.com]

Awareness of the pathophysiology and echocardiographic appearance of venous air embolism may aid in prompt recognition and potential therapy for this lethal complication of mechanical ventilation. [ncbi.nlm.nih.gov]

We present the current data regarding the pathophysiology of microemboli and their clinical consequences. Read More… Pathophysiology and clinical implications of microbubbles during hemodialysis. [clearlinemd.com]

introduction of a small volume of air into venous circulation usually well tolerated - primary pathophysiological event is intense vasoconstriction of pulmonary circulation (air lock effect interferes with RV outflow). [aic.cuhk.edu.hk]

While the chapters discuss definitions, pathophysiology, clinical course, complications, and prognosis, the primary emphasis is devoted to patient management. [books.google.com]

Awareness of VAE or its prevention did not correlate with the level of physician training, experience, or specialty. After the educational intervention, concern for and awareness of proper methods of prevention of VAE improved (p < .001). [ncbi.nlm.nih.gov]

Conclusions Venous air embolisms are preventable, and can lead to sizeable indemnity awards. [sages.org]

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