Air Embolism Research Articles

Systemic air embolism associated with endoscopic retrograde cholangiopancreatography: A case report

BACKGROUND Endoscopic retrograde cholangiopancreatography (ERCP) is a key procedure for diagnosing and treating biliary and pancreatic disorders. Although effective, it carries risks, including rare but severe complications such as air embolism. CASE SUMMARY We report a case of a 58-year-old man who developed extensive air embolism during ERCP. He previously underwent a Whipple procedure and experienced a sudden drop in vital signs and loss of consciousness. Immediate intervention with hyperbaric oxygen therapy and supportive care led to gradual recovery. Imaging confirmed widespread air embolism, which resolved with continued treatment. CONCLUSION Air embolism is a rare, critical complication of ERCP, especially in patients with prior surgery such as pancreaticoduodenectomy. Early detection and prompt treatment, including hyperbaric oxygen therapy, are crucial for favorable outcomes.

Is there a rationale for hyperbaric oxygen therapy in the patients with Post COVID syndrome? : A critical review.

The SARS-CoV-2 pandemic has resulted in 762 million infections worldwide from 2020 to date, of which approximately ten percent are suffering from the effects after infection in 2019 (COVID-19) [1, 40]. In Germany, it is now assumed that at least one million people suffer from post-COVID condition with long-term consequences. These have been previously reported in diseases like Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS). Symptoms show a changing variability and recent surveys in the COVID context indicate that 10-30 % of outpatients, 50 to 70% of hospitalised patients suffer from sequelae. Recent data suggest that only 13% of all ill people were completely free of symptoms after recovery [3, 9]. Current hypotheses consider chronic inflammation, mitochondrial dysfunction, latent viral persistence, autoimmunity, changes of the human microbiome or multilocular sequelae in various organ system after infection. Hyperbaric oxygen therapy (HBOT) is applied since 1957 for heart surgery, scuba dive accidents, CO intoxication, air embolisms and infections with anaerobic pathogens. Under hyperbaric pressure, oxygen is physically dissolved in the blood in higher concentrations and reaches levels four times higher than under normobaric oxygen application. Moreover, the alternation of hyperoxia and normoxia induces a variety of processes at the cellular level, which improves oxygen supply in areas of locoregional hypoxia. Numerous target gene effects on new vessel formation, anti-inflammatory and anti-oedematous effects have been demonstrated [74]. The provision of intermittently high, local oxygen concentrations increases repair and regeneration processes and normalises the predominance of hyperinflammation. At present time only one prospective, randomized and placebo-controlled study exists with positive effects on global cognitive function, attention and executive function, psychiatric symptoms and pain interference. In conclusion, up to this date HBO is the only scientifically proven treatment in a prospective randomized controlled trial to be effective for cognitive improvement, regeneration of brain network and improvement of cardiac function. HBOT may have not only theoretical but also potential impact on targets of current pathophysiology of Post COVID condition, which warrants further scientific studies in patients.

Coronary air embolism causing myocardial infarction following a blunt chest trauma.

Coronary air embolism causing myocardial infarction following a blunt chest trauma.

Abstract 4135360: Eosinophilic Myocarditis: An Atypical Presentation with a Labile Course: A Case Report

Case presentation: A 64-year-old man presented with one day of chest pain. Initial evaluation showed elevated cardiac enzymes (CE) and normal eosinophil count. Electrocardiogram (EKG) was unremarkable. Transthoracic echocardiogram (TTE) showed an ejection fraction (EF) of 40% and a moderate-large pericardial effusion with signs of tamponade. Pericardiocentesis was deferred due to the lack of a safe window. Left and right heart catheterization showed no occlusive disease or chamber pressure equalization. The patient developed worsening shock, raising suspicion for myocarditis and prompting an endomyocardial biopsy (EMB). He was placed on extracorporeal membrane oxygenation (ECMO) on day 3. The EMB resulted as eosinophilic myocarditis (EM), and high dose Methylprednisolone was started. He was decannulated from ECMO on day 10. Intra-operative transesophageal echocardiogram (TEE) post-decannulation showed a normal EF without segmental abnormalities. Three hours later, a rise in CEs was noted, and EKG showed ST elevations inferiorly. TTE showed a reduced EF with multiple segmental abnormalities concerning for myocardial infarction. A repeat coronary angiogram was unremarkable. Due to the residual pericardial effusion, the patient underwent a pericardial window draining 200 cc of serosanguinous fluid. Intra-operative TEE showed an EF of 20% with no improvement after drainage. He had a cardiac arrest during the procedure and was placed back on ECMO. High-dose steroids were resumed along with intravenous immunoglobulin. Despite interventions, the patient continued to deteriorate and he ultimately expired. Discussion: EM has high mortality and a variable course, often requiring EMB for diagnosis. As in our case, about 25% of cases present without peripheral eosinophilia. Pericardial effusion occurs in 34% of cases and tamponade in 6%. A distinct feature of this case is the decompensation associated with ST elevation and segmental abnormalities, thought initially to be myocardial infarction (MI), after an initial response to steroids. While the etiology of such decompensation is unclear, relapsing EM in the setting of tapering steroids is one explanation, as myocarditis and MI can share similar clinical features. Another explanation is cardiac tamponade, which has also been reported to mimic MI and myocarditis. Air embolism from ECMO decannulation is another possibility, though air embolisms may include cerebrovascular pathology, which was not observed.

Outcomes and Complications of Posterior Fossa Surgery in Sitting Versus Park-Bench Positions

Background/Objectives: Patient positioning during surgery can influence intra- and postoperative complications. Therefore, we assessed the impact of the sitting and park-bench positions on anesthetic parameters and complications in neurosurgical patients. Methods and Patients: For this retrospective study, 314 adults who underwent neurosurgical procedures for posterior fossa pathologies were divided into two groups: sitting (n = 231) and park-bench (n = 83). The following data were collected, monitored, recorded, and compared: age, sex, tumor type, surgical approach, cardiovascular and respiratory complications, and postoperative surgical complications. The association of hypotension with the position was further investigated through multivariate logistic regression models by adjusting for CO2 decrease, desaturation, and documented gas embolism. Results: The average age was significantly lower in the sitting group (55 years, interquartile range (IQR) = 43–63; female proportion = 59.74%) than in the park-bench group (62 years, IQR = 45–74; female proportion = 57.83%) (p < 0.001). Cerebellopontine angle tumors were detected in 37.23% of the patients who underwent an operation in the sitting position and in 7.26% who underwent an operation in the park-bench position (p < 0.001). Patients in the sitting position had significantly greater anesthetic complication (91.77% vs. 71.08%, p < 0.001), hypotension (61.9% vs. 16.87%), and >2 mmHg CO2 decrease (35.06% vs. 15.66%, p < 0.001) incidences. Hypoxemia and death occurred more frequently in the park-bench group (8.43% vs. 1.73% and 6.03% vs. 1.3%, respectively). Conclusions: Compared with the park-bench position, the sitting position was associated with a greater specific anesthetic complication incidence and lower postoperative mortality rate, indicating a need for careful risk-benefit assessment when selecting each individual patient’s surgical position.

Gas embolism in double-balloon endoscopic retrograde cholangiography with carbon dioxide insufflation.

Gas embolism in double-balloon endoscopic retrograde cholangiography with carbon dioxide insufflation.

Delayed-Onset Arterial Gas Embolism After Underwater Egress Training

BACKGROUND: Arterial gas embolism (AGE) may occur while breathing compressed air and failing to exhale during ascent to compensate for gas expansion as pressure decreases. Trauma to the lungs from over-pressurization may result in air bubbles entering the pulmonary veins and subsequently the systemic circulation, causing obstructed blood flow and inflammatory cascades. AGEs are known to always manifest within 10 min of surfacing from depth. In underwater egress training (UET), which is mandatory for U.S. Marines, service members learn to escape from a tilt-wing or rotor aircraft after it submerges and inverts in water. CASE REPORT: We report a case of cerebral AGE in which the victim experienced neurological symptoms more than 1 h after completing UET at a depth between only 3.28–6.56 ft (1–2 m). The patient was treated with a U.S. Navy Treatment Table 6 and experienced complete resolution of symptoms. DISCUSSION: This case is one of only two AGEs reported with symptom onset occurring after 10 min of surfacing from depth to be published. AGE at depths between 1–2 m has only been reported on three other occasions, and dysbarism injuries during UET are also exceedingly rare. This case demonstrates a situation in which all three events occurred, highlighting the need for increased awareness and clinical consideration of delayed AGE in similar scenarios despite the commonly held belief that AGEs do not occur outside of 10 min of surfacing. Harvey SE, Reynolds RP, Fisher JF. Delayed-onset arterial gas embolism after underwater egress training. Aerosp Med Hum Perform. 2024; 95(11):867–870.

Role of 3D-electro-anatomical mapping on procedural characteristics and outcomes in pulsed-field ablation for atrial fibrillation

Abstract Introduction While the utilization of dedicated 3D-electro-anatomical mapping (EAM) systems for catheter ablation of atrial fibrillation (AF) is crucial using radiofrequency, its potential benefits in pulsed-field ablation (PFA) remain uncertain. This is of particular interest, since some PFA ablation systems will soon be available with integrated 3D-EAM capabilities. Objectives To compare the procedural characteristics and outcomes of patients undergoing PFA for pulmonary vein isolation (PVI) with mapping and with no mapping. Methods We prospectively enrolled patients undergoing their first PVI at a tertary referral center. In patients undergoing PVI with mapping, a multipolar mapping catheter was used to create voltage maps during sinus rhythm pre- and post-ablation. In the non-mapping group PVI was confirmed by assessing entrance block via the PFA catheter. The first 30 cases with mapping were excluded to account for a potential learning curve. Results A total of 197 consecutive patients were included (age 65 [interquartile range (IQR) 58 – 72] years; indexed left atrial volume 40 [IQR 35 – 44] mL/m2). Among these, 127 patients (64%) underwent PVI with mapping and 70 patients (36%) with no mapping. The median procedure duration, left atrial dwell time and the fluoroscopic time for the mapping vs the non-mapping group were 55 [IQR 45 – 67] min vs. 28 [IQR 23 – 35] min (p < 0.001), 38 [IQR 30 – 49] min vs. 15 [IQR 11 – 21] min (p < 0.001), 11 [IQR 9 – 14] min vs. 8 [IQR 7 – 11] min (p < 0.001), respectively. In the mapping group in 9% (11/127 patients) at least 1 PV was incompletely isolated and required additional applications. Acute PVI success was 100%. There were two complications in the mapping group (one stroke, one coronary artery air embolism) and none were observed in the non-mapping group. The recurrence rate of atrial arrythmias during a median follow-up of 267 [IQR 164 – 419] days was 14% in the mapping group and 17% in the non-mapping group, p = 0.728. Conclusion In conclusion, the use of PFA with no mapping was associated with a significant decrease in procedural characteristics, while AF-recurrence was not significantly different. The routine use of mapping for PFA-PVI may not be needed.Figure 1

The Emboless® venous chamber efficiently reduces air bubbles: a randomized study of chronic hemodialysis patients

Abstract Background When blood passes the extracorporeal circuit, air microbubbles (MBs) contaminate the blood. Some MBs will end up as microemboli in the lung, heart, and brain. MB exposure has no medical purpose and is considered as bio-incompatibility. Selecting venous chambers with high removal rate of MBs is warranted to reduce the risks of air bio-incompatibility. The primary aim was to compare the Fresenius 5008 (F5008-VC) and the Emboless® (Emboless-VC) venous chambers regarding the elimination of MBs in the return bloodline during hemodialysis (HD). Methods Twenty patients underwent 80 sessions of cross-over HD using both the F5008-VC and the Emboless-VC randomized such that half started with the F5008-VC and half with the Emboless-VC. For 32 of the 80 sessions measurements were also performed during hemodiafiltrations (HDF) after the initial HD. MBs were measured with an ultrasound device (within the size range of 20-500µm) at the ‘Inlet’ and ‘Outlet’ bloodline of the venous chambers. The Wilcoxon pairwise test compared the percentage of MB elimination between venous chambers. Results During HD, the median reduction of MBs for the Outlet was 39% with the F5008-VC and 76% with the Emboless-VC (p<0.001). During HDF, the reduction was 28% with the F5008-VC and 70% with the Emboless-VC (p<0.001). Conclusion Fewer MBs and subsequently fewer microemboli entered the bloodline of the patient using the Emboless-VC compared to the F5008-VC venous chamber during HD and during HDF. Venous chambers with a high removal rate of MBs will reduce the extent of air emboli.

Evaluation of a Physiologic-Driven Closed-Loop Resuscitation Algorithm in an Animal Model of Hemorrhagic Shock.

Appropriate resuscitation from hemorrhagic shock is critical to restore tissue perfusion and to avoid over-resuscitation. The objective of this study was to test the ability of a closed-loop diagnosis and resuscitation algorithm called resuscitation from shock using functional hemodynamic monitoring using invasive monitoring (ReFit1) and minimally invasive monitoring (ReFit2) to identify, treat, and stabilize a porcine model of severe hemorrhagic shock. We created a ReFit algorithm using dynamic hemodynamic parameters of pulse pressure variation (PPV), stroke volume variation (SVV), dynamic arterial elastance (Eadyn = PPV/SVV), driven by mean arterial pressure (MAP), mixed venous oxygen saturation, and heart rate targets to define the need for fluids, vasopressors, and inotropes. University-based animal laboratory. Twenty-seven female pigs. Anesthetized, intubated, and ventilated (8 mL/kg) pigs were bled at 10 mL/min until a MAP of less than 40 mm Hg, held for 30 minutes, then resuscitated. The ReFit algorithm used the above dynamic parameters to drive computer-controlled infusion pumps to deliver blood, lactated Ringer's solution, norepinephrine, and in ReFit1 dobutamine. In four animals, after initial resuscitation from hemorrhagic shock, the ability of the ReFit1 algorithm to treat acute air embolism-induced pulmonary hypertension and right heart failure was also tested. In 10 ReFit1 and 17 ReFit2 animals, the time to stabilization from shock was not dissimilar to open controlled resuscitation performed by an expert physician (52 ± 12, 50 ± 13, and 60 ± 15 min, respectively) with similar amounts of fluids and norepinephrine needed. In four ReFit1 animals after initial stabilization, the algorithm successfully resuscitated the animals after inducing an acute air embolism right heart failure, with all animals recovering stability within 30 minutes. Our physiologically based functional hemodynamic monitoring-centered closed-loop resuscitation system can effectively diagnose and treat cardiovascular shock due to hemorrhage and air embolism.

Combining occlusion of the right hepatic vein with the Pringle maneuver in laparoscopic anatomic right posterior liver resection.

Laparoscopic right posterior anatomic resection (LRPAR) presents challenges due to uncontrollable hemorrhage from the inferior vena cava and the risk of carbon dioxide (CO2) gas embolism. However, there is a lack of research specifically addressing the safe exposure of right hepatic vein (RHV). Herein, we introduced a novel technique of combining occlusion of the RHV with the Pringle maneuver and presented the outcomes of our initial series. All consecutive patients who underwent LRPAR using this novel technique were enrolled in this study from March 2021 to January 2024. The demographic characteristics, perioperative outcomes and follow-up data were collected and analyzed. A total of 12 patients underwent LRPAR using the technique of double occlusion during study period. All the procedures were performed laparoscopically, with no conversions to open surgery. The median operative time was 203min (range of 172-279min) and the median blood loss was 200ml (range of 50-280ml). No patient received a blood transfusion during the perioperative period. Of note, the main trunk of the RHV was fully exposed on the cutting surface in all cases, and no evidence of CO2 gas embolism was observed following double occlusion. None of the patients suffered from Clavien-Dindo grade II or higher postoperative complications, and the perioperative mortality was nil. The median postoperative stay was 5days (range of 5-7days). The median hospitalization cost was 43,048.5 RMB (40,240.35-57,921.53 RMB). At a median follow-up period of 24months (range of 4-35months), all patients were alive with normal daily living and no disease recurrence was observed. Combining occlusion of the right hepatic vein with the Pringle maneuver appears to be a feasible and expected technique for securing the exposure of RHV in LRPAR. Further follow-up and well-designed prospective comparative studies are needed to validate the feasibility and efficacy of this technique.

A human cadaveric model for venous air embolism detection tool development.

A human cadaveric model combining standard lung protective mechanical ventilation and modified cardiac bypass techniques was developed to allow investigation into automated modes of detection of venous air emboli (VAE) prior to in vivo human or animal investigations. In this study, in order to create an artificial cardiopulmonary circuit in a cadaver that could mimic VAE physiology, the direction of flow was reversed from conventional cardiac bypass. Normal saline was circulated in isolation through the heart and lungs as opposed to the peripheral organs by placing the venous cannula into the aorta and the arterial cannula into the inferior vena cava with selective ligation of other vessels. Mechanical ventilation and this reversed cardiac bypass scheme allowed preliminary detection of VAE independently but not in concert in our current simulation scheme due to pulmonary edema in the cadaver. A limited dissection approach was used initially followed by a radical exposure of the great vessels, and both proved feasible in terms of air signal detection. We used electrical impendence as a preliminary tool to validate detection in this cadaveric model however we theorize that it would work for echocardiographic, intravenous ultrasound or other novel modalities as well. A cadaveric model allows monitoring technology development with reduced use of animal and conventional human testing.

Coronary Air Embolism During Lung Biopsy: A Rare but Insidious Problem

Coronary Air Embolism During Lung Biopsy: A Rare but Insidious Problem

Induction of Cerebral Arterial Gas Embolism in Rat.

We present a methodological approach for preclinical research of cerebral arterial gas embolism (CAGE), a condition characterized by gas bubbles within the cerebral circulation causing multifocal ischemia. The current work describes two surgical methods to induce CAGE in the rat: one with injection of air via the external carotid artery (ECA), thereby sacrificing the vessel, and one via direct injection into the common carotid artery (CCA). Male Wistar rats were used and divided into groups (n=5) to undergo either the ECA- or CCA-entry method with injection of different air emboli volumes (6000, 7000 and 8000 nL) or sham surgery. A custom-made bubble generator was used to produce gas emboli with consistent size, and open-source software was developed for real-time bubble analysis. The comparison between the two methods revealed the CCA approach to be superior in terms of consistent bubble production within the bubble generator, reduced embolization time and fewer complications.

Fatal Consequences of Head Trauma: A Case Report of Venous Air Embolism Complicated by Substance Abuse and Liver Disease

Fatal Consequences of Head Trauma: A Case Report of Venous Air Embolism Complicated by Substance Abuse and Liver Disease

Air embolism during unsuccessful transcatheter closure of secundum atrial septal defect in a patient with an undetected left-sided inferior vena cava.

A 46-year-old man with a history of secundum atrial septal defect and interstitial lung disease was admitted to the hospital for a planned transcatheter closure of the atrial septal defect. Following multiple failed attempts to place a right femoral vein catheter, the procedure was aborted. Another attempt was made to the left femoral vein, but that attempt was complicated by an unfamiliar resistance. Even though resistance was met during insertion, the catheter was further inserted until a position in the inferior vena cava above the liver was obtained at fluoroscopy. Simultaneously, the patient became unresponsive. The procedure was immediately aborted and the atrial septal defect closure was not completed. Air embolism to the heart and brain was detected using echocardiography and computed tomography. The patient died 15 days after the procedure. Death was attributed to severe cerebral edema due to air embolism. The autopsy revealed a left-sided inferior vena cava. This case report demonstrates that unexpected congenital vascular anomalies complicating a routine transcatheter closure of the atrial septal defect can result in a fatal outcome.

Right-to-left-shunts in patients scheduled for neurosurgical intervention in semi-sitting position – a literature review based on two case scenarios

BackgroundNeurosurgery performed in the semi-sitting position provides advantages for certain procedures. However, this approach is associated with potential complications, particularly venous air embolism. Due to typically negative venous pressure at the wound site, air can be drawn into the veins. This risk is especially high in patients presenting with an intra- or extracardiac right-to-left-shunt. Transoesophageal echocardiography can be used to detect a patent foramen ovale or other possible pulmonary-systemic shunt before placing the patient in the sitting position.Case presentationIn this report, we present two young patients undergoing scheduled microsurgical vestibular schwannoma removal in a semi-sitting position who were diagnosed with congenital heart defects during routine perioperative assessment to detect possible intracardiac right-to-left shunts, using pre- and intraoperative transesophageal echocardiography (TEE) and additionally conducting an agitated saline bubble study under Valsalva manoeuvre. Patient A was diagnosed with a persistent left superior vena cava and Patient B with an unroofed coronary sinus (UCS). These findings confronted the anesthesiological and surgical teams with difficult individual decisions regarding further perioperative management.ConclusionsPerioperative transesophageal echocardiography is a diagnostic tool to both detect intraoperative position-related air embolisms and to rule out intracardiac right-to-left shunts, e.g. a patent foramen ovale, in order to decide for or against a (semi-)sitting position. Depending on the surgical circumstances a semi-sitting positioning of patients presenting with an intracardiac right-to-left-shunt, e.g. a PFO, can be feasible in individual cases if there is an implemented therapeutic algorithm to immediately terminate significant venous air entry. However, since certain other intra- or extracardiac right-to-left-shunts, such as here presented PLSVC or UCS, are rare, there is no definitive way of estimating the amount of entered air through detected shunts or anomalous vessels. Therefore, it is recommended to avoid a (semi-)sitting position in favour of a lateral or prone position for a patient undergoing intracranial surgery, once the perioperative TEE shows air bubbles in the left atrium or ventricle whose origins cannot be defined solely through TEE for certain in order to ensure patient safety by minimizing the risk of intraoperative paradoxical air embolisms.

Gas Embolism Complicating Endoscopic Retrograde Cholangiopancreaticography: Case Report of a Complex Condition

Gas Embolism Complicating Endoscopic Retrograde Cholangiopancreaticography: Case Report of a Complex Condition

Risk factors associated with air embolism following computed tomography-guided percutaneous lung biopsy: a retrospective case-control study.

Retrospective analysis to identify the risk factors for air embolism following computed tomography (CT)-guided percutaneous transthoracic needle biopsy (TNB). A retrospective analysis of patients who underwent CT-TNB at The First Affiliated Hospital of Zhengzhou University and Xuzhou Cancer Hospital from January 2017 to December 2021 was performed. A total of 21 factors relevant to air embolisms were collected. Risk factors associated with air embolisms were determined by the least absolute shrinkage and selection operator (LASSO). The receiver-operator characteristic (ROC) was used to assess the ability of these factors to identify air embolisms. Of these 32,748 patients, 28 experienced air embolisms (19 at The First Affiliated Hospital of Zhengzhou University (incidence, 1.46%) and nine at Xuzhou Cancer Hospital (incidence, 0.69%); total incidence, 2.16%). Only seven patients exhibited symptoms (symptom rate, 25.00%). A total of 21 patients were asymptomatic at the time of swept-source CT. No deaths occurred. We found through univariate and multivariate analysis that eight out of these 21 factors are associated with the occurrence of air embolism. The area under the ROC curve was 0.721, indicating good predictive power (P<0.05). Cough during the procedure, hemoptysis during the procedure, the distance between the mass and the pulmonary vein, the presence of a cavity in the lesion, lesion location, number of samples, abnormalities in the patient's coagulation mechanism, and the puncture position may be the risk factors for air embolism in CT-TNB.

Middle cerebral artery hypodense dot sign in iatrogenic air embolism.

Air embolism is a rare cause of stroke, usually associated with medical procedures, with gastrointestinal endoscopy rarely implicated. Here, we present a case of a patient who experienced cerebral air embolism post-gastroscopy, presenting with aphasia and right hemiparesis due to left M2 occlusion with spontaneous and complete recovery. CT scan revealed a hypodense defect in the left Sylvian fissure, representing a "hypodense dot sign" suggestive of an air embolism. The hypodense MCA sign, previously described in fat embolism cases, could also indicate air embolism, supporting prompt diagnosis and proper intervention.