Transesophageal echocardiography detection of air embolism during endoscopic surgery and validity of hyperbaric oxygen therapy: Case report.

INTRODUCTION: Air embolism has the potential to be serious and fatal. In this paper, we report 3 cases of air embolism associated with endoscopic medical procedures in which the patients were treated with hyperbaric oxygen immediately after diagnosis by transesophageal echocardiography. In addition, we systematically review the risk factors for air embolism, clinical presentation, treatment, and the importance of early hyperbaric oxygen therapy efficacy after recognition of air embolism. PATIENT CONCERNS: We present 3 patients with varying degrees of air embolism during endoscopic procedures, one of which was fatal, with large amounts of gas visible in the right and left heart chambers and pulmonary artery, 1 showing right heart enlargement with increased pulmonary artery pressure and tricuspid regurgitation, and 1 showing only a small amount of gas images in the heart chambers. DIAGNOSES: Based on ETCO2 and transesophageal echocardiography (TEE), diagnoses of air embolism were made. INTERVENTIONS: The patients received symptomatic supportive therapy including CPR, 100% O2 ventilation, cerebral protection, hyperbaric oxygen therapy and rehabilitation. OUTCOMES: Air embolism can causes respiratory, circulatory and neurological dysfunction. After aggressive treatment, one of the 3 patients died, 1 had permanent visual impairment, and 1 recovered completely without comorbidities. CONCLUSIONS: While it is common for small amounts of air/air bubbles to enter the circulatory system during endoscopic procedures, life-threatening air embolism is rare. Air embolism can lead to serious consequences, including respiratory, circulatory, and neurological impairment. Therefore, early recognition of severe air embolism and prompt hyperbaric oxygen therapy are essential to avoid its serious complications.

Hyperbaric treatment of air or gas embolism: current recommendations.

Gas can enter arteries (arterial gas embolism, AGE) due to alveolar-capillary disruption (caused by pulmonary over-pressurization, e.g. breath-hold ascent by divers) or veins (venous gas embolism, VGE) as a result of tissue bubble formation due to decompression (diving, altitude exposure) or during certain surgical procedures where capillary hydrostatic pressure at the incision site is subatmospheric. Both AGE and VGE can be caused by iatrogenic gas injection. AGE usually produces stroke-like manifestations, such as impaired consciousness, confusion, seizures and focal neurological deficits. Small amounts of VGE are often tolerated due to filtration by pulmonary capillaries; however VGE can cause pulmonary edema, cardiac "vapor lock" and AGE due to transpulmonary passage or right-to-left shunt through a patient foramen ovale. Intravascular gas can cause arterial obstruction or endothelial damage and secondary vasospasm and capillary leak. Vascular gas is frequently not visible with radiographic imaging, which should not be used to exclude the diagnosis of AGE. Isolated VGE usually requires no treatment; AGE treatment is similar to decompression sickness (DCS), with first aid oxygen then hyperbaric oxygen. Although cerebral AGE (CAGE) often causes intracranial hypertension, animal studies have failed to demonstrate a benefit of induced hypocapnia. An evidence based review of adjunctive therapies is presented.

Massive portal venous gas embolism after scuba diving.

INTRODUCTION: Portal venous gas from a diving injury is an infrequent finding and only a few cases are described. We report a case of severe decompression sickness (DCS) associated with a massive amount of gas in the portal and mesenteric veins. CASE REPORT: A 49-year-old man suffered from DCS after two deep dives on the same day. He presented with cutaneous, neurological and pulmonary symptoms associated with hypoxaemia. He had no abdominal pain. A computed tomography (CT) scan showed large quantities of hepatic and portal venous gas and excluded other explanations for its presence. All symptoms disappeared with hyperbaric oxygen therapy and there were no further complications. DISCUSSION AND CONCLUSION: The role of portal venous gas in DCS is not obvious. Isolated portal venous gas seems to cause no obvious harm. Medical imaging should be considered for differential diagnosis and to prevent some complications, especially in divers presenting with abdominal pain.

Barotrauma and Arterial Gas Embolism: A Diving Emergencies Simulation Case for Emergency Medicine Residents.

Introduction: Arterial gas embolism (AGE) is a rare but severe complication of scuba diving. While AGE is most commonly encountered in coastal areas with high volumes of recreational divers, at-risk populations exist throughout the United States, making basic knowledge of the disease important for all emergency medicine (EM) physicians. Methods: We used a hypothetical simulation case to train EM residents on diagnosis and management of AGE. A 32-year-old male presented with shortness of breath and unilateral neurologic deficits immediately after scuba diving. Residents were challenged to emergently diagnose and treat tension pneumothorax followed by diagnosis and treatment of AGE. A resident, attending, and simulation technician ran the case for four separate simulation teams in the simulation center with the addition of chest tube supplies to the basic resuscitation bay setup. Teams were allowed to use the internet in real time as a reference tool. Results: Most teams arrived at the correct diagnosis using real-time internet searches, but none found the Divers Alert Network Emergency Hotline. Learners were debriefed both immediately and in a formal lecture. A follow-up survey showed good retention of knowledge. Discussion: This case fills a significant knowledge and training gap for many EM physicians. AGE is a rare but highly morbid complication of diving, and EM residents should have knowledge of the disease and available consultation resources. Most EM residents will not have the opportunity to treat a diver during training, and the simulation environment provides a means to teach and practice this skill set.

Hyperbaric oxygen therapy for cerebral air gas embolism following orthotopic heart transplant: case report.

Air gas embolism (AGE) is a rare complication of cardiac surgery, with high morbidity and mortality. We present a case of suspected AGE following orthotopic heart transplant. The patient received hyperbaric oxygen therapy with near-complete resolution of symptoms at follow-up. This case exemplifies the difficulty in diagnosis of AGE, the considerations involved in the treatment of a critical care patient in a hyperbaric chamber, and utility in treating a patient for AGE even after a delay in diagnosis.

Cerebrospinal vascular diseases misdiagnosed as decompression illness: the importance of considering other neurological diagnoses.

The diagnosis of decompression illness (DCI), which is based on a history of decompression and clinical findings, can sometimes be confounded with other vascular events of the central nervous system. The authors report three cases of divers who were urgently transported to a hyperbaric facility for hyperbaric oxygen treatment of DCI which at admission turned out to be something else. The first case, a 45-year-old experienced diver with unconsciousness, was clinically diagnosed as having experienced subarachnoid hemorrhage, which was confirmed by CT scan. The second case, a 49-year-old fisherman with a hemiparesis which occurred during diving, was diagnosed as cerebral stroke, resulting in putaminal hemorrhage. The third case, a 54-year-old fisherman with sensory numbness, ataxic gait and urinary retention following sudden post-dive onset of upper back pain, was diagnosed as spinal epidural hematoma; he also showed blood collection in the spinal canal. Neurological insults following scuba diving can present clinically with confusing features of cerebral and/or spinal DCI. We emphasize the importance of considering cerebral and/or spinal vascular diseases as unusual causes of neurological deficits after or during diving.

Air embolism: diagnosis and management.

Air embolism is an uncommon, but potentially life-threatening event for which prompt diagnosis and management can result in significantly improved patient outcomes. Most air emboli are iatrogenic. Arterial air emboli may occur as a complication from lung biopsy, arterial catheterization or cardiopulmonary bypass. Immediate management includes placing the patient on high-flow oxygen and in the right lateral decubitus position. Venous air emboli may occur during pressurized venous infusions, or catheter manipulation. Immediate management includes placement of the patient on high-flow oxygen and in the left lateral decubitus and/or Trendelenburg position. Hyperbaric oxygen therapy is the definitive treatment which may decrease the size of air emboli by facilitating gas reabsorption, while also improving tissue oxygenation and reducing ischemic reperfusion injury.

Pulmonary Air Embolism: An Infrequent Complication in the Radiology Suite.

BACKGROUND Air embolism can occur in a number of medical-surgical situations. Venous air embolism is frequently lethal when a substantial amount enters the venous circulation rapidly and can lead to significant morbidity if crossover to the systemic arterial circulation occurs. The diagnosis of massive air embolism is usually made on clinical grounds by the development of abrupt hemodynamic compromise. The true incidence, morbidity, and mortality of this event is unknown given the difficulties in diagnosis. CASE REPORT An inadvertent antecubital venous injection of 150 mL of air using a contrast power injector during a computed tomography (CT) is reported. Immediate imaging (CT) showed a significant amount of air in the right atrium and right ventricular cavity, and air mixed with contrast in the main pulmonary artery and proximal divisions of the pulmonary circulation. Patient condition deteriorated requiring mechanical ventilation for 48 hours. Condition improved over the next few days and patient was successfully extubated and discharged home. CONCLUSIONS Air embolism is a rare complication, the potential for this to be life threatening makes prevention and early detection of this condition essential. This condition should be suspected when patients experience sudden onset respiratory distress and/or experience a neurological event in the setting of a known risk factor. Treatment options include Durant's maneuver; left-lateral decubitus, head-down positioning; to decrease air entry into the right ventricle outflow tract, hyperbaric therapy, 100% O2 and supportive care.

[Diving accidents]. / Tauchunfälle.

Decompression injuries occur on account of the special hyperbaric effects during the emerge phase and require superior therapeutic knowledge. Vitally important is emergency treatment with high concentrated oxygen at an early stage. Sever decompression injuries require oxygenation in a hyperbaric treatment chamber.

Transient cortical blindness after intradiscal oxygen-ozone therapy.

A 54-year-old caucasian male developed bilateral blindness during an oxygen-ozone injection for disc herniation. The visual loss (VL) was immediately followed by severe frontal headache, vomiting, and nausea. The patient underestimated the VL showing Anton's syndrome, with a complete visual recovery after 2-month follow-up. Magnetic resonance data were consistent with recent ischemic lesions in bilateral vascular territories of posterior cerebral arteries.

Accuracy of a SET of Screening Parameters Developed for the Diagnosis of Arterial Gas Embolism: The SANDHOG Criteria.

BACKGROUND: Arterial gas embolism (AGE) is a major cause of morbidity and mortality in self-contained underwater breathing apparatus (SCUBA) diving and certain medical procedures. There are currently no well-defined criteria to diagnose AGE. Emergency physicians often find themselves facing a decision whether or not a patient with dive-related symptoms has an AGE and needs to be transferred to a hyperbaric facility. OBJECTIVES: The objective of this study was to test the accuracy of diagnostic criteria developed by the San Diego Hyperbaric Oxygen Group (SANDHOG) for the diagnosis of AGE. METHODS: This was a retrospective review of consultations completed by the Hyperbaric Medicine Department (HBO) at the University of California San Diego where the diagnosis of AGE was considered. HBO staff blinded to the purpose of the study identified potential cases of AGE. The criterion standard was the final diagnosis by a panel of HBO specialists also blinded to the purpose of this study. Descriptive statistics and comparisons evaluating SANDHOG criteria compared to the criterion standard were performed. RESULTS: Twenty-six patients were identified for inclusion. Twenty-three of 26 (88%) were SCUBA divers, 2 had intravascular gas injections, and 1 patient had a military training chamber accident. Nineteen of 26 (73%) patients were diagnosed with AGE. A SANDHOG score of 2 had 94.7% sensitivity (95% confidence interval [CI] 71.9-99.7), 85.7% specificity (95% CI 42.0-99.2), positive likelihood ratio of 6.6 (95% CI 1.1-40.8), and negative likelihood ratio of 0.06 (95% CI 0.01-0.43) for AGE. A SANDHOG score <2 had a negative predictive value of 100% for AGE. CONCLUSION: The SANDHOG criteria appear to be reliable in diagnosing AGE. AGE is unlikely with SANDHOG scores <2, whereas SANDHOG scores ≥2 resulted in high sensitivity and specificity for AGE. Emergency physicians may find this tool useful in evaluating patients for suspected AGE, and it may assist in determining whether to transfer the patient to a hyperbaric facility. Future studies should be performed to further examine and validate the accuracy and inter-rater reliability of this tool.

Case of vascular air embolism during holmium laser enucleation of the prostate.

Vascular air embolism is a rare complication during transurethral surgery. A case of air embolism during holmium laser enucleation of the prostate in a 76-year-old man is presented. During the step of morcellation, the patient's blood pressure suddenly oscillated up and down, and end-tidal CO2 and arterial saturation decreased. Transesophageal and transthoracic echocardiography showed air collection in the right atrium. It was also discovered that incorrect assembly of the tube from the morcellator caused rapid entrainment of air into the vein. Computed tomography and abdominal X-ray showed niveau formation in the femoral vein and air collection in the pelvic retroperitoneal space. The patient recovered with careful observation and was discharged 7 days after the operation with no sequelae. This report is presented to remind urologists of this unusual complication that can occur during holmium laser enucleation of the prostate procedures.

A systematic review of factitious decompression sickness.

We present a case of factitious decompression sickness (DCS) involving a patient emergently treated at a hyperbaric medicine facility in New Zealand. Patients with factitious disorder feign illnesses such as DCS in order to receive care and attention despite the lack of an underlying illness. Other studies have suggested that 0.6% to as many as 9.3% of hospital admissions are factitious in nature. Therefore we believe that factitious DCS is occurring more often than hyperbaric clinicians suspect. DCS can be life-threatening, and hyperbaric medicine clinicians will almost always "err on the side of caution" when patients are referred with symptoms of DCS. Because DCS can be diagnosed based on subjective symptoms and self-reported history, there are opportunities for factitious patients to receive hyperbaric therapy. The costs associated with factitious DCS include transport, staff resources and preventing patients with treatable conditions from accessing the hyperbaric chamber. We performed a systematic review of the literature and found eight additional reported cases of confirmed or suspected factitious DCS. We report our findings and recommendations for hyperbaric medicine specialists regarding the recognition and management of factitious DCS.

An unusual cerebral air embolism developing within the posterior circulation territory after a needle lung biopsy.

We herein report the case of a 75-year-old woman with a paradoxical cerebral air embolism (CAE). She developed a bilateral visual disturbance at the time of needle puncture during a computed tomography (CT)-guided percutaneous needle lung biopsy in the face down position. The air density within the descending aorta on chest CT suggested the presence of a cerebral air embolism. Brain MRI demonstrated increased signal intensity in the bilateral occipital lobes on diffusion-weighted images. Usually, CAE occurs predominantly in the right hemisphere for anatomical reasons. The face down position and the anatomical features of the right subclavian artery, which diverges backward from the brachiocephalic artery, might explain such a unique distribution of CAE in this patient.