Air embolism complicating gastrointestinal endoscopy: A systematic review

Cerebral arterial air embolism after esophageal stenting for recurrence of gastroesophageal junction cancer: a case report

Cerebral arterial air embolism (CAE) is a rare complication after esophageal stenting, but it can be life-threatening. It is especially a concern for those with a history of previous gastrointestinal cancer therapies. We report a case of CAE after esophageal stenting in a patient with recurrent gastroesophageal junction cancer and a history of multiple cancer treatments. A 71 year-old man with a history of a proximal gastrectomy, resection of the lower esophagus, chemotherapy, and radiation presented to our hospital 2 weeks after stenting with epigastric and back pain. Mediastinitis was suspected and conservative treatment was begun. The patient suddenly developed altered mental status, left hemiplegia, and anisocoria after drinking water. A brain computed tomography (CT) revealed right-sided predominance of multifocal CAE. Chest and abdominal CT showed a hematoma in the gastric and duodenal wall and an intraluminal hematoma from the esophagus, around the stent, to the upper ileum. CAE was thought to be due to rupture of the recurrent tumor. Unfortunately, despite intensive care, the patient died about 5 h after the onset of neurological symptoms. It has been reported that prior treatments, such as chemotherapy and radiotherapy, increase the risk of life-threatening adverse events, including CAE after esophageal stenting. Clinicians should keep in mind the possibility of CAE after esophageal stenting in patients with a history of multiple cancer treatments.

The i-EUS consensus on the management of pancreatic fluid collections - Part 1

Pancreatic fluid collections (PFCs), including pancreatic pseudocysts (PPs) and walled-off pancreatic necrosis (WON), are common complications of pancreatitis and pancreatic surgery. Historically, the treatment of these conditions has relied on surgical and radiological approaches; however, it has later shifted toward an endoscopy-based approach. With the development of dedicated lumen-apposing metal stents (LAMS), interventional Endoscopic Ultrasound (EUS)-guided procedures have become the standard approach for PFC drainage. However, there is still limited consensus on several aspects of the multidisciplinary management of PFCs. The interventional endoscopy and ultrasound (i-EUS) group is an Italian network of clinicians and scientists with special interest in biliopancreatic interventional endoscopy, especially interventional EUS. This manuscript describes the first part of the results of a consensus conference organized by i-EUS with the aim of providing evidence-based guidance on aspects such as indications for treating PFCs, the timing of intervention, and different technical strategies for managing patients with PFCs.

Air embolism complicating endoscopic retrograde cholangiopancreatography

Aim: Venous air embolism is a rare but potentially life threatening complication of endoscopic retrograde cholangiopancreatography. Diagnosis is difficult because of the lack of specific signs or symptoms. Case: A 62-year-old man underwent endoscopic retrograde cholangiopancreatography for choledocholithiasis. A cardiovascular collapse occurred during the procedure. The echocardiography showed air within the right ventricle. Aspiration of air from the right ventricle was done and saved the patient's life. Conclusion: We highlight through this case that increased awareness is essential for prompt recognition of the air embolism to allow life-saving therapy.

Investigation of air bubble behaviour after gas embolism events induced in a microfluidic network mimicking microvasculature

Gas embolism is a medical condition that occurs when gas bubbles are present in veins or arteries, decreasing blood flow and potentially reducing oxygen delivery to vital organs, such as the brain. Although usually reported as rare, gas embolism can lead to severe neurological damage or death. However, presently, only limited understanding exists regarding the microscale processes leading to the formation, persistence, movement, and resolution of gas emboli, as modulated by microvasculature geometrical features and blood properties. Because gas embolism is initially a physico-chemical-only process, with biological responses starting later, the opportunity exists to fully study the genesis and evolution of gas emboli using in vitro microfluidic networks mimicking small regions of microvasculature. The microfluidics networks used in this study, which aim to mimic microvasculature geometry, comprise linear channels with T-, or Y-junction air inlets, with 20, 40, and 60 μm widths (arterial or venous), and a 30 μm width honeycombed network (arterial) with three bifurcation angles (30°, 60°, and 90°). Synthetic blood, equivalent to 46% haematocrit concentrations, and water were used to study the modulation of gas embolism-like events by liquid viscosity. Our study shows that (i) longer bubbles with lower velocity occur in narrower channels, e.g., with 20 μm width; (ii) the resistance of air bubbles to the flow increases with the higher haematocrit concentration; and lastly (iii) the propensity of gas embolism-like events in honeycomb architectures increases for more acute, e.g., 30°, bifurcation angles. A dimensionless analysis using Euler, Weber, and capillary numbers demarcated the conditions conducive to gas embolism. This work suggests that in vitro experimentation using microfluidic devices with microvascular tissue-like structures could assist medical guidelines and management in preventing and mitigating the effects of gas embolism.

Venous air emboli during esophagoscopy confirmed by computed tomographic pulmonary angiography -a case report

BACKGROUND

Esophagogastroduodenoscopy (EGD) is vital for the diagnosis and treatment of various gastrointestinal conditions but carries a low risk of venous air embolism (VAE). We report a case of VAE during EGD, confirmed by computed tomographic pulmonary angiography (CTPA).

CASE

A 56-year-old male with a history of hypopharyngeal cancer underwent EGD for dysphagia-related esophageal dilation. Signs of VAE were noted, prompting swift interventions, including oxygen therapy, positional changes, and CTPA. CTPA revealed the Mercedes-Benz sign, pneumomediastinum, and a minimal pneumothorax. The patient's oxygen saturation improved within 30 min before undergoing CTPA, and he was discharged on postoperative day 4.

CONCLUSIONS

Timely recognition of VAE, resulting in appropriate interventions supported by CTPA, resulted in favorable patient outcomes.

Gas Embolism After a Patient's Ninth ERCP Procedure

Gas embolism is a rare and potentially fatal complication of endoscopic retrograde cholangiopancreatography (ERCP). We present a 66-year-old man who developed gas embolism after undergoing therapeutic ERCP for cholangitis. Some risk factors of gas embolism in this patient included stones in the common bile duct with cholangitis and a history of multiple ERCP procedures. Early diagnosis and rapid treatment of this potentially fatal complication resulted in our patient's full recovery.

Diffuse Bi-hemispheric Cortical Infarction Secondary to Cerebral Air Embolism After Elective Esophagogastroduodenoscopy: A Case Report and Review of Literature

Cerebral air embolism (CAE) is a rare entity and is more often secondary to iatrogenic causes. We present a rare case of CAE post esophagogastroduodenoscopy (EGD) with a shower of emboli resulting in diffuse cortical infarction. An 80-year-old man with gastroesophageal reflux disease underwent an elective EGD for esophageal dilatation. During the procedure, there was significant arterial and venous bleeding which subsided with treatment. After the procedure, the patient became comatose with the decerebrate extensor posturing to painful stimulation. Computed tomography without contrast revealed multiple foci of CAE. Diffusion-weighted magnetic resonance images performed at the same time showed numerous areas of acute ischemic lesions affecting primarily the Gray Matter, demonstrating both cortical micro air emboli and bi-hemispheric, global hypoperfusion leading to cortical ribboning pattern.  There have been less than 22 cases of CAE after EGD in the literature, most of which were middle cerebral arterial territory infarctions. Our clinical images represent one of the extremely rare cases showing a shower of emboli and global hypoperfusion-induced gray matter infarction due to CAE-causing brain herniation.

Gas Pressure From the Endoscope: An Unexplored Contributor to Morbidity and Mortality?

Background It has been shown that the incidence of venous air embolism and venous carbon dioxide (CO₂) embolism is high during endoscopic retrograde cholangiopancreatography (ERCP). We examined insufflating gas flow and maximum pressure produced by three types of commonly used endoscopes because we could not readily locate technical data for endoscope gas flow and maximum emitted pressure in the manufacturer's manuals. Methods We tested the Olympus GIF-Q180 used for esophagogastroduodenoscopy, the CF-Q180 used for colonoscopy, and the TJF-Q180 used for ERCP (Olympus America Inc., Center Valley, Pennsylvania). Under three different clinical gas insufflation scenarios, we measured in vitro maximum gas pressure transduced from a closed space created at the endoscope tip in a worst-case scenario analysis. Results We showed that it is readily possible to generate a pressure (>5-30 times normal central venous pressure) in the air space at the tip of all three endoscopes when insufflation is activated and the gas egress is limited. Conclusions These findings shed additional light on in vivo occurrences of gas embolism during gastrointestinal endoscopy. We postulate that in addition to using exclusively CO₂ as the insufflating gas, the risk of gas embolism can be further diminished by regulating insufflating gas pressure at the tip of endoscopes.

Acute air embolism caused by autotransfusion during percutaneous atrial septal defect closure: A case report

Atrial septal defect is a common congenital heart disease in adults and it is often asymptomatic. Percutaneous device closure is gaining popularity, but percutaneous repair of atrial septal defect leading to left atrial rupture and subsequent autotransfusion under high pressure leading to air embolism has not been reported yet.

Suspected cerebrovascular air embolism during endoscopic esophageal varices ligation under sedation with fatal outcome: A case report

BACKGROUND

Air embolism is a very rare, yet serious and potentially fatal complication of digestive endoscopic treatment. Air embolism is the result of air directly entering the arteries or veins. However, to recognize neurological dysfunction under sedation can be difficult. Therefore, it is extremely important to identify high-risk groups and take preventive measures.

CASE SUMMARY

Herein, we report a 74-year-old female patient with esophageal varices who suffered from consciousness disturbance after the third endoscopic ligation of esophageal varices under sedation. Combined with the patient’s imaging examination results and medical history, we highly suspected that the patient had developed paradoxical cerebral air embolism during endoscopic ligation. We learned that the patient died at a later follow-up. In order to be able to identify and prevent the occurrence of air embolism early, we summarize and analyze the risk factors, pathogenesis, clinical manifestations, prevention and treatment options of gastrointestinal endoscopy complicated by cerebral air embolism.

CONCLUSION

Electroencephalographic monitoring helps to recognize the occurrence of air embolism in time and increase the patient's chance of survival.

Anesthesia for Advanced Endoscopic Procedures

The gastrointestinal endoscopy paradigm is rapidly changing, and technological advancements are largely responsible. In tandem, anesthesia providers are adapting to the changing needs and demands. The challenges are unique. Complications arising from the procedures are both routine, such as aspiration and hypoxia, and procedure specific, such as bleeding, pneumothorax, pneumopericardium, and pneumoperitoneum. It is crucial for the anesthesia provider to have a good understanding of the techniques employed by the endoscopist. A higher index of suspicion is also essential to diagnose and appropriately manage many of the complications. In this review, an effort is made to discuss both procedural aspects and anesthesia challenges. We hope that both endoscopists and anesthesia providers will benefit from this review.

Massive cerebral air embolism following percutaneous transhepatic biliary drainage: A case report

RATIONALE

Cerebral air embolism from portal venous gas rarely occurs due to invasive procedures (e.g., endoscopic procedures, liver biopsy, or percutaneous transhepatic biliary drainage) that disrupt the gastrointestinal or hepatobiliary structures. Here, we report a rare case of fatal cerebral air embolism following a series of percutaneous transhepatic biliary drainage tube insertions.

PATIENT CONCERNS

A 50-year-old woman with a history of cholecystectomy, liver wedge resection, and hepaticojejunostomy for gallbladder cancer presented with altered mental status 1 week after percutaneous transhepatic biliary drainage tube placement.

DIAGNOSES

Extensive cerebral air embolism and acute cerebral infarction.

INTERVENTIONS

Brain computed tomography and magnetic resonance imaging, hyperbaric oxygen therapy, medical therapy.

OUTCOMES

Despite the use of hyperbaric oxygen therapy and medical treatment including vasopressors, the patient eventually died due to massive systemic air embolism.

LESSONS

To date, there have been no reports of cerebral air embolism due to percutaneous transhepatic biliary drainage with pronounced radiologic images. We reviewed previously reported fatal cases associated with endoscopic hepatobiliary procedures and assessed the possible mechanisms and potential causes of air embolism.

Cerebral Air Embolism After Gastrointestinal Procedure: A Case Report and Literature Review

Esophagogastroduodenoscopy (EGD) is one of the forefronts of minimally invasive modalities with excellent safety records and tremendous capability but despite its accolades and functions, there are still very rare complications including air embolism. It is a life-threatening condition that could lead to a significant increase in morbidity and mortality. However, there are limited data for incidence of air embolism in association with gastrointestinal endoscopy. Diagnosis of air embolism after or during gastrointestinal endoscopy might be a difficult task due to overlapping presentations with anesthesia effects on the cardiopulmonary and the neurological systems, as a result, there should be increased awareness allowing clinicians to quickly rule out air embolism in patient with altered mental status or cardiopulmonary changes after or during gastrointestinal endoscopy. Herein, we report a unique case of cerebral air embolism after EGD in a 79-year-old female patient. In addition, we also performed a systematic review of cases based on PRISMA guideline, with the aim to investigate the demographics and clinical outcomes associated with this complication. This systematic review of cases hopes to increase the awareness about this rare entity.

Two cases of fatal iatrogenic air embolism confirmed by autopsies

The occurrence of air embolism is highly related to medical operations, and air embolism can cause sudden death. Such situations require attention in forensic work. This article reports two cases of iatrogenic air embolism confirmed by autopsy. In case 1, air embolism occurred after hydrogen peroxide was used to irrigate and disinfect a wound on the patient's left forearm. Approximately 90 ml of 3% hydrogen peroxide solution was used in case 1, and this volume can produce approximately 890 ml of oxygen by complete decomposition, which is far more than the average lethal air embolism volume. Attention should be given to the risk of air embolism when using hydrogen peroxide for irrigation and disinfection. In case 2, air embolism occurred during left ureteroscopy and stent placement. Due to inappropriate processing, the normal saline pump infused air into the patient at a high pressure of 120 mmHg. Based on our autopsy findings, we discuss the pathways of arterial air embolism and cerebral air embolism. In addition to the air entrainment volume and accumulation rate, the location of air accumulation also significantly impacts the risk of air embolism. After an arterial air embolus develops into a coronary and/or cerebral air embolus, the lethal air volume drops to only a few milliliters.

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.

When in Trouble Think of the Bubble: Paradoxical Cerebral Arterial Gas Embolism after Endoscopic Retrograde Cholangiopancreatography

Air embolism (a result of direct communication with the vasculature and an external pressure gradient from the gastrointestinal or the biliary tract), although rare, is a potentially devastating adverse event seen in endoscopic retrograde cholangiopancreatography (ERCP) procedures. Whether venous, arterial, or paradoxical, the clinical presentation ranges from asymptomatic patients to cardiorespiratory arrest. This is of particular importance because it makes the diagnosis of air embolism even more difficult in an already sedated patient. Since early recognition increases the chances of patients' survival, endoscopists should be highly motivated and trained to recognize this complication as early as possible. With only 60 cases of air embolism reported (and even fewer related to paradoxical air embolism), we aimed to report a case of paradoxical cerebral air embolism in a patient undergoing ERCP due to a common bile duct stricture and to provide a mini-review of this clinical entity that can serve as a bedside quick reference guide for endoscopists worldwide.

Vaginal laceration leading to air embolism during consensual sexual intercourse

Vaginal injuries with clinical complications apart from local bleeding following sexual intercourse are thought to be rare events that have recently fostered a discussion on the topic. We report a case of a vaginal laceration resulting in death caused by air embolism in a non-pregnant woman during consensual sexual intercourse with digital and penile penetration. Hysterectomy and a preexisting vaginal injury were additional risk factors present in this case. Besides case history and autopsy findings, histological examination of the vaginal lesion and postmortem computer tomography (PMCT) helped in diagnosing the cause of death and underlying pathophysiological mechanisms.

Peroral Cholangioscopy: How Technology and Imaging Have Changed ERCP

Endoscopic retrograde cholangiopancreatography (ERCP) is the minimally invasive standard of care for the treatment of several biliary and pancreatic pathologies. One of the limitations of this technique is the lack of endoluminal vision within the biliary tree or Wirsung's duct. This limits the diagnostic accuracy of the procedure and reduces the effectiveness of many treatments. Technological progress and the use of increasingly ergonomic and high-definition imaging equipment have led to the dissemination of peroral cholangioscopy (POC). Thanks to the high quality of video image resolution, POC could well be a powerful tool used to characterize malignant biliary strictures. It could also allow targeted biopsies or local treatments, hence reducing the risk of complications and increasing outcomes. The technological improvement of the last generation of POC is opening new horizons in the treatment of biliopancreatic pathologies, thereby contributing to refine and enhance the ERCP management of several diseases in the near future.

Clinical Presentation, Diagnosis, and Management of Air Embolism During Endoscopic Retrograde Cholangiopancreatography

Endoscopic retrograde cholangiopancreatography (ERCP) is a minimally invasive procedure that is widely used by endoscopists and has a robust therapeutic profile. It uses endoscopy and imaging for a variety of diagnostic as well as therapeutic purposes. It is used for the management of a lot of pancreaticobiliary diseases such as obstructive jaundice, obstruction related to bile ducts, pancreatic biliary tumors, and traumatic or iatrogenic damage to the bile ducts. Other therapeutic interventions that can be done via ERCP include sphincterotomy, dilation of strictures, removal of biliary stones and placement of stents. Air embolism presents with cardiovascular, pulmonary, and neurologic signs and symptoms. Treatment of air embolism should be started early in suspected cases, and it should be in the differential diagnoses of various complications secondary to high risk of ERCP, especially if a cardiopulmonary compromise is present. Air embolism is rare but a serious complication associated with ERCP. The physicians must keep this in mind while performing ERCP in patients with predisposing risk factors. This review highlights the mechanism, causes, risk factors, pathophysiology, clinical signs, diagnostic modalities, treatment, and preventive measures to deal with this catastrophic complication.

The Way to Man's Heart Is through the Stomach

Organ systems do not exist in a vacuum. However, in an era of increasingly specialized medicine, the focus is often on the organ system alone. Many symptoms are associated with differential diagnoses from upper gastrointestinal (GI) and cardiovascular medical and surgical specialties. Furthermore, a large number of rare but deadly conditions cross paths between the upper GI tract and cardiovascular system; a significant proportion of these are iatrogenic injuries from a parallel specialty. These include unusual fistulae, herniae, and embolisms that transcend specialties. This review highlights these conditions and the shared anatomy and embryology of the two organ systems.

Air embolism secondary to endoscopy in hospitalized patients: results from the National Inpatient Sample (1998-2013)

Background:

Air embolism is a rare, but potentially catastrophic complication of endoscopic procedures. We herein evaluated the overall incidence of air embolism after endoscopy. We also measured mortality outcomes after air embolism.

Methods:

Patients who underwent endoscopy as an index procedure during hospitalization were selected from the National Inpatient Sample from 1998-2013. The primary outcome of interest was the incidence of air embolism after endoscopy. All-cause mortality after endoscopy was measured as a secondary outcome and the Charlson Comorbidity Index was calculated. Binary logistic regression was used to explore the effect of air embolism on inpatient mortality, using P<0.05 as level of significance.

Results:

A total of 2,245,291 patients met the inclusion criteria. Mean age at the time of procedure was 62.5 years. Esophagogastroduodenoscopy (EGD) was the most common endoscopic procedure, accounting for 80% of endoscopic procedures. Air embolism occurred in 13 cases, giving a rate of 0.57 per 100,000 endoscopic procedures. Air embolism was most common after endoscopic retrograde cholangiopancreatography (ERCP), occurring in 3.32 per 100,000 procedures, compared with 0.44 and 0.38 per 100,000 procedures for EGD and colonoscopy, respectively. The case fatality rate for post endoscopic air embolism was 15.4%. After adjusting for covariates, air embolism after endoscopy was independently associated with higher odds of inpatient mortality: odds ratio 10.35, 95% confidence interval 1.21-88.03 (P<0.03).

Conclusions:

Air embolism is most common after ERCP. It is frequently associated with disorders involving a breach to the gastrointestinal mucosa or vasculature. Though rare, it is an independent predictor of inpatient mortality.

Systemic air embolism as a complication of gastroscopy

Gastroscopy is a common medical procedure with a low complication rate. Most complications are related to respiratory or cardiovascular incidents, especially in sedated patients. Systemic air embolism secondary to gastroscopy is one of the most serious complications, which has been described in few case reports. We describe an interesting case of gastroscopy-related systemic air embolism in a 73-year-old patient.

Complications of endoscopic retrograde cholangiopancreatography: an imaging review

Endoscopic retrograde cholangiopancreatography (ERCP) has currently become an inseparable tool in the gastroenterologist's armamentarium for treatment of pancreaticobiliary disorders. Given the increase in number of therapeutic ERCP procedures today, the need for prompt and correct diagnosis of its complications is pivotal. This review discusses the mechanisms, risk factors, imaging findings and general management aspects of common and rare complications of ERCP. Furthermore, the review elaborates on imaging indications, recommended protocol and normal imaging findings post ERCP.

Nonoperating Room Anesthesia: Anesthesia in the Gastrointestinal Suite

Exponential growth in endoscopy suite procedures due to technological advances requires teamwork between anesthesiologists, endoscopists, nursing teams, and technical and support staff. The current standard of care for moderate sedation includes a combination of anxiolytic drugs and analgesic drugs and sometimes are not adequate to ensure patient safety, efficiency, and comfort. The use of anesthesia services can improve safety, recovery, turnovers, and efficiency. The article discusses comprehensive preoperative evaluation, optimization of comorbidities, and intraoperative airway management strategies to deliver safe and efficient anesthesia, given the need to share the airway and allow the use of carbon dioxide in the gastrointestinal suite.

Pneumodissection during Percutaneous Renal Ablation Resulting in Air Embolism: Percutaneous Management and a Review of the Literature

Percutaneous renal ablation is a nephron-sparing approach for selected patients with renal cell carcinoma. Common complications include hemorrhage, injury to the urinary collecting system, and abscess formation. The purpose of this article is to present a case of vascular air embolism as a complication of pneumodissection performed during percutaneous ablation of renal cell carcinoma, discuss its successful percutaneous management, review common complications of renal ablation, and outline steps physicians can take to lessen these complications.

Air Embolism during Upper Endoscopy: A Case Report

Air embolism is a rare complication of upper endoscopy and potentially causes life-threatening events. A 67-year-old man with a history of surgery of cardiac carcinoma and pancreatic neuroendocrine tumor underwent painless upper endoscopy because of tarry stools. During the procedure, air embolism developed, which caused decreased pulse oxygen saturation and delayed sedation recovery. He recovered with some weakness of the left upper limb in the intensive care unit without hyperbaric oxygen therapy. The etiology, clinical manifestations, and treatments of air embolism are discussed based on the literature reports. Although air embolism is uncommon in endoscopic examinations, the patients’ outcomes could be improved if clinicians are alert to this potential complication, and promptly start proper diagnostic and therapeutic measures.

Gas embolism during endoscopic retrograde cholangiopancreatography: diagnosis and management

Air embolism is rarely diagnosed and is often fatal. The diagnosis is often not made in a timely manner given the rapid and severe clinical deterioration that often develops, frequently leading to cardiac arrest. Many patients are only diagnosed post-mortem. With the increasing use of endoscopic retrograde cholangiopancreatography, air embolism should be considered in the differential diagnosis in patients who experience sudden clinical deterioration during or immediately after the procedure. Clinical suspicion is key in the diagnosis and management of air embolism. Use of precordial Doppler ultrasound and transesophageal echocardiogram can aid in the diagnosis of air embolism. Once the diagnosis is made, supportive management of airway, breathing and circulation is pivotal. Advanced cardiac life support should be initiated when necessary. Fluid resuscitation and vasopressors can improve cardiac output. Hyperbaric oxygen therapy should be considered when possible in cases of suspected cerebral air embolism cases to improve neurological outcome. A multidisciplinary team approach and effective communication with experts, potentially including an anesthesiologist, cardiologist, intensivist, radiologist and surgeon, can improve the outcome in air embolism.

Cholangioscopy in the digital era

Cholangioscopy allows direct visualization and subsequent therapeutic maneuvers of the biliary ductal system. With advances in endoscopic and imaging technology, cholangioscopy has become an important modality for the diagnosis of indeterminate biliary strictures and an essential therapeutic tool for difficult to remove biliary stones. Enhanced imaging and operability of the latest generation cholangioscopes have further expanded their clinical applications to include ductal tumor ablation, gallbladder drainage, access to difficult to reach branches of the biliary tree, and biliary foreign body manipulation. In this review, we discuss the technical evolution of cholangioscopy into the digital era and review the clinical evidence supporting its use in the diagnosis and therapy of biliary tract disease.

A case of retrograde venous air embolism causing cerebral infarction following upper gastrointestinal endoscopy: A novel pathophysiological mechanism

The incidence of cerebral infarction following upper gastrointestinal endoscopic procedures is well described in the existing literature, with most mechanisms involving arterial travel of the embolus. We describe a case of cerebral infarction not explained by previously described mechanisms and detail the proposed occurrence of retrograde venous air embolism causing cerebral infarction following an upper gastrointestinal endoscopic procedure.

Pediatric Endoscopic Procedure Complications

PURPOSE OF REVIEW

This review summarizes the current body of research, define high-risk patients and endoscopic processes, and outline evidence-based countermeasures aimed at minimizing the incidence of complications during endoscopy in children.

RECENT FINDINGS

Significant complications of endoscopy requiring emergency department or inpatient admission in otherwise healthy children are unusual, but more common with therapeutic procedures; risk from procedures increases incrementally with preoperative coexisting conditions. Duodenal hematoma is predominantly a pediatric endoscopic complication and is more likely in hematology-oncology patients. Air embolism is a well-defined endoscopic retrograde cholangiopancreatography (ERCP) complication in adults and is likely to increase in children with increased performance of pediatric ERCP. Increased physician expertise is the most often proposed countermeasure, especially in the context of endoscopy complications in the higher-risk patient and procedure. Endoscopy in children remains a very safe group of procedures, although a more detailed understanding of risk factors and ideal training and practice organization is lacking.

Massive air embolism as a complication of upper gastrointestinal endoscopy: A case report illustrating a stroke mimic, literature review, and suggested management

Cerebral air embolism should be considered in case of stroke symptoms during any invasive procedure. Transport to a hospital with neurosurgical/hyperbaric oxygen treatment (HBOT) facility could improve the outcome for the patient. Absence of air on computed tomography (CT) scan should not disqualify a patient from HBOT if air embolism is suspected.

Uncommon Occurrences of Air Embolism: Description of Cases and Review of the Literature

Many different risk factors have been associated with the occurrence of gas embolism making this potentially lethal complication easily avoidable. However, this condition can occur in circumstances not commonly reported. Three different and extremely uncommon cases of gas embolism are presented and discussed: the first was caused by the voluntary ingestion of hydrogen peroxide, the second occurred during a retrograde cholangiopancreatography, and the last followed the intrapleural injection of Urokinase. Whereas in the first patient the gas embolism was associated with only relatively mild digestive symptoms, in the remaining two it caused a massive cerebral ischemia and an extended myocardial infarction, respectively. Despite a hyperbaric oxygen therapy performed timely in each case, only the first patient survived. The classical risk factors associated with gas embolism like indwelling central venous catheters, diving accidents, etc. are rather well known and thus somewhat preventable; however, a number of less common and difficult-to-recognize causes can determine this condition, making the correct diagnosis elusive and delaying the hyperbaric oxygen therapy, whose window of opportunity is rather narrow. Thus, a gas embolism should be suspected in the presence of not otherwise explainable sudden neurologic and/or cardiovascular symptoms also in circumstances not typically considered at risk.

Vascular air embolism: A silent hazard to patient safety

PURPOSE

To narratively review published information on prevention, detection, pathophysiology, and appropriate treatment of vascular air embolism (VAE).

MATERIALS AND METHODS

MEDLINE, SCOPUS, Cochrane Central Register and Google Scholar databases were searched for data published through October 2016. The Manufacturer and User Facility Device Experience (MAUDE) database was queried for "air embolism" reports (years 2011-2016).

RESULTS

VAE may be introduced through disruption in the integrity of the venous circulation that occurs during insertion, maintenance, or removal of intravenous or central venous catheters. VAE impacts pulmonary circulation, respiratory and cardiac function, systemic inflammation and coagulation, often with serious or fatal consequences. When VAE enters arterial circulation, air emboli affect cerebral blood flow and the central nervous system. New medical devices remove air from intravenous infusions. Early recognition and treatment reduce the clinical sequelae of VAE. An organized team approach to treatment including clinical simulation can facilitate preparedness for VAE. The MAUDE database included 416 injuries and 95 fatalities from VAE. Data from the American Society of Anesthesiologists Closed Claims Project showed 100% of claims for VAE resulted in a median payment of $325,000.

CONCLUSIONS

VAE is an important and underappreciated complication of surgery, anesthesia and medical procedures.

Endoscopic Bubble Trouble: Hyperbaric Oxygen Therapy for Cerebral Gas Embolism During Upper Endoscopy

Gas embolism is a rare but potentially devastating complication of endoscopic procedures. We describe 3 cases of gas embolism which were associated with endoscopic procedures (esophagogastroduodenoscopy and endoscopic retrograde cholangiopancreatography). We treated these at our hyperbaric medicine center with 3 different outcomes: complete resolution, death, and disability. We review the literature regarding this unusual complication of endoscopy and discuss the need for prompt identification and referral for hyperbaric oxygen therapy. Additional adjunctive therapies are also discussed.

Two Cardiac Arrests Because of Venous Air Embolism During Endoscopic Retrograde Cholangiopancreatography: A Case Report

Venous air embolism is a rare but potentially catastrophic complication of endoscopic retrograde cholangiopancreatography. We report 2 cases of venous air embolism and subsequent cardiac arrests. During resuscitation efforts, a transesophageal echocardiogram was placed, which demonstrated significant air in the right heart. Although gastroenterologists seem to be more aware of this complication, it is underreported in the anesthesiology literature. As anesthesiologists continue to expand coverage to endoscopy suites, anesthesia providers must be aware of predisposing factors and maintain a high index of suspicion to recognize and treat in a timely manner to prevent serious adverse outcomes.

Systemic air embolism complicating upper gastrointestinal endoscopy: a case report with post-mortem CT scan findings and review of literature

Endoscopy of the gastrointestinal and biliary tract is a common procedure and is routinely performed for therapeutic and diagnostic purposes. Perforation, bleeding and infection are some of the more common reported side effects. Air embolism on the other hand, is a rare complication of gastrointestinal endoscopy. We report a 77-year-old African-American female with a history of pancreatic cancer, which was resected with a Whipple procedure. As part of diagnostic and therapeutic procedure, an endoscopic retrograde cholangiopancreatography was planned several months after the surgery. The patient's heart rate suddenly slowed to 40 bpm during the procedure and she became cyanotic and difficult to oxygenate after the endoscope was introduced and CO₂ gas was insufflated. A forensic autopsy was performed with post-mortem computed tomography (PMCT) and revealed extensive systemic air embolism. The detailed PMCT and autopsy findings are presented and current literature is reviewed.

Effects of carbon dioxide insufflation during direct cholangioscopy on biliary pressures and vital parameters: a pilot study in porcine models

BACKGROUND AND AIMS

Direct per-oral cholangioscopy allows endoscopic visualization of the biliary tract. Insufflation with carbon dioxide (CO₂) is an alternative to saline solution irrigation during direct cholangioscopy. There are no data on maximal CO₂ insufflation in direct cholangioscopy without causing biliary barotrauma or fatal gas embolism. We aimed to evaluate the safety of increasing CO₂ insufflation in direct cholangioscopy without causing biliary barotrauma or fatal gas embolism.

METHODS

This was an in vivo animal study. Four domestic pigs, under general endotracheal anesthesia, were used. The first animal was used to validate the feasibility of direct cholangioscopy and biliary pressure measurements, after which all animals underwent laparotomy, insertion of a pressure transducer in the cystic duct, and direct transpapillary placement of the cholangioscope. The common bile duct (CBD) and cystic duct were ligated to contain the instilled gas and exclusively expose the biliary tree. Insufflation of CO₂ started at 200 mL/min and was continuously increased until there was evidence of bile duct rupture (as measured by a drop in intraductal pressures) or instability of vital signs (hypotension, bradycardia, bradypnea, O₂ desaturation). Necropsy was performed on all animals to assess the liver and biliary system for evidence of barotrauma.

RESULTS

CO₂ was insufflated up to 8 L/min without causing bile duct rupture or instability in vital signs despite increasing CBD pressure with insufflation. There was significant correlation between CO₂ flow with partial pressure of CO₂ in arterial blood (PaCO₂) (coefficient, 0.96-1.00; P < .01) and end tidal expired CO₂ (EtCO₂) (coefficient, 0.94-1.00; P < .01). However, the pulse rate, respiratory rate, arterial blood pressure, and O₂ did not correlate with the amount of CO₂ flow. There was no evidence of hepatic or biliary barotrauma on necropsy.

CONCLUSIONS

This pilot experience in porcine models suggests that CO₂ insufflation is safe for direct cholangioscopy and does not result in biliary barotrauma or vital signs instability.