Factors associated with favorable response to hyperbaric oxygen therapy among patients presenting with iatrogenic cerebral arterial gas embolism

Air emboli during neuroendovascular procedure treated with hyperbaric oxygen therapy

Air embolism is a rare complication of endovascular procedures with hyperbaric oxygen therapy (HBOT) as a potential treatment. We report a male patient in his 40s presented to the emergency department with the following fluctuating symptoms: headache, aphasia, bilateral arm and hand weakness, numbness and blurry vision. Medical history included remote vertebral artery dissection, hypertension and tobacco use. Initial head CT was normal; CT angiogram revealed bilateral internal carotid artery dissections with significant stenosis. He was taken for emergent carotid intervention. During the intervention, the patient developed agitation, bradycardia and respiratory distress, necessitating intubation. Dyna CT revealed air emboli. HBOT was initiated, leading to complete resolution of air emboli and small haemorrhages after one session. Post-treatment, the patient showed neurological improvement, was extubated and later discharged with mild residual aphasia and dysarthria. This case underscores air emboli as a rare complication in the neurointerventional suite and highlights HBOT as a feasible treatment.

Early hyperbaric oxygen therapy is associated with favorable outcome in patients with iatrogenic cerebral arterial gas embolism: systematic review and individual patient data meta-analysis of observational studies

BACKGROUND

Iatrogenic cerebral arterial gas embolism (CAGE) caused by invasive medical procedures may be treated with hyperbaric oxygen therapy (HBOT). Previous studies suggested that initiation of HBOT within 6-8 h is associated with higher probability of favorable outcome, when compared to time-to-HBOT beyond 8 h. We performed a group level and individual patient level meta-analysis of observational studies, to evaluate the relationship between time-to-HBOT and outcome after iatrogenic CAGE.

METHODS

We systematically searched for studies reporting on time-to-HBOT and outcome in patients with iatrogenic CAGE. On group level, we meta-analyzed the differences between median time-to-HBOT in patients with favorable versus unfavorable outcome. On individual patient level, we analyzed the relationship between time-to-HBOT and probability of favorable outcome in a generalized linear mixed effects model.

RESULTS

Group level meta-analysis (ten studies, 263 patients) shows that patients with favorable outcome were treated with HBOT 2.4 h (95% CI 0.6-9.7) earlier than patients with unfavorable outcome. The generalized linear mixed effects model (eight studies, 126 patients) shows a significant relationship between time-to-HBOT and probability of favorable outcome (p = 0.013) that remains significant after correcting for severity of manifestations (p = 0.041). Probability of favorable outcome decreases from approximately 65% when HBOT is started immediately, to 30% when HBOT is delayed for 15 h.

CONCLUSIONS

Increased time-to-HBOT is associated with decreased probability of favorable outcome in iatrogenic CAGE. This suggests that early initiation of HBOT in iatrogenic CAGE is of vital importance.

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.

Iatrogenic stroke caused by cerebral air embolism and acute reperfusion therapy using hyperbaric oxygen

Objective:

Air embolisms are mostly iatrogenic and a rare yet dreaded complication following percutaneous procedures. Intravascular entrapment of air can result in occlusion of end arteries and subsequent tissue ischemia and infarction. Cerebrovascular occlusions caused by air embolisms are time-sensitive and an uncommon cause of ischemic stroke, warranting an alternative acute management and reperfusion strategy.

Methods:

During a CT-guided lung biopsy, the patient developed left-sided paresis and sensory deficits prior to loss of consciousness. CT revealed air in the aorta, both ophthalmic arteries and vessels in the right parietal region. The patient was swiftly air-lifted to the nearest hyperbaric oxygen chamber for an alternate emergency reperfusion therapy. The following eight days the patient received hyperbaric oxygen therapy and gradually improved. Nine days after symptom onset he was discharged with a minor left facial palsy.

Conclusions

Cerebrovascular occlusions are critical events regardless of etiology. Air embolism is rare but potentially catastrophic and can occur during both percutaneous procedures and surgeries. Vigilance and knowledge of this potential complication are needed to rapidly provide beneficial treatment. That is, high flow oxygen and correct positioning pending hyperbaric oxygen therapy.

Decompression Illness in Repetitive Breath-Hold Diving: Why Ischemic Lesions Involve the Brain?

Nitrogen (N₂) accumulation in the blood and tissues can occur due to breath-hold (BH) diving. Post-dive venous gas emboli have been documented in commercial BH divers (Ama) after repetitive dives with short surface intervals. Hence, BH diving can theoretically cause decompression illness (DCI). “Taravana,” the diving syndrome described in Polynesian pearl divers by Cross in the 1960s, is likely DCI. It manifests mainly with cerebral involvements, especially stroke-like brain attacks with the spinal cord spared. Neuroradiological studies on Ama divers showed symptomatic and asymptomatic ischemic lesions in the cerebral cortex, subcortex, basal ganglia, brainstem, and cerebellum. These lesions localized in the external watershed areas and deep perforating arteries are compatible with cerebral arterial gas embolism. The underlying mechanisms remain to be elucidated. We consider that the most plausible mechanisms are arterialized venous gas bubbles passing through the lungs, bubbles mixed with thrombi occlude cerebral arteries and then expand from N₂ influx from the occluded arteries and the brain. The first aid normobaric oxygen appears beneficial. DCI prevention strategy includes avoiding long-lasting repetitive dives for more than several hours, prolonging the surface intervals. This article provides an overview of clinical manifestations of DCI following repetitive BH dives and discusses possible mechanisms based on clinical and neuroimaging studies.

[What is the Best Therapeutic Strategy for Decompression Illness? First Aid Oxygen Inhalation and Hyperbaric Oxygen Therapy]

Decompression illness (DCI), a syndrome following inadequate reduction in environmental pressure, has two forms: decompression sickness and arterial gas embolism after pulmonary barotrauma. Recompression therapy using oxygen, a kind of hyperbaric oxygen therapy, has been considered the gold standard treatment for DCI, although there is no randomized controlled trial evidence for its use. We evaluated the effectiveness of recompression therapy in treating DCI by reviewing the reported therapeutic results of serious DCI, especially neurological disorders. Early or ultra-early recompression therapy did not dramatically improve clinical recovery from DCI symptoms, including spinal cord disorders. In contrast, early first aid normobaric oxygen inhalation highly improved or stabilized clinical conditions of DCI. Based on these clinical results, the international committee for hyperbaric and diving medicine has stated that cases of mild DCI may be managed without recompression therapy. Further work is needed to clarify the clinical utility of recompression therapy for spinal injury as a common symptom of DCI. We also point out that the Japanese decree "Ordinance on Safety and Health of Work under High Pressure", which describes work under hyperbaric environments, has some serious issues and should be amended on the basis of scientific evidence.

Paradoxical carbon dioxide embolism during laparoscopic surgery without intracardiac right-to-left shunt: two case reports and a brief review of the literature

We herein report two cases of paradoxical carbon dioxide (CO₂) embolism during laparoscopic nephrectomy and hepatic left lateral lobectomy without evidence of a right-to-left shunt or obvious rupture of blood vessels. Transesophageal echocardiography detected paradoxical CO₂ embolism before the end-tidal CO₂ partial pressure (P_ETCO₂) dropped from baseline. The pneumoperitoneum was reduced or stopped immediately after detection of the embolism. One patient developed a postoperative epileptiform seizure. In the other patient, many gas bubbles were drawn out from the central venous line. We speculate that rapid introduction of pneumoperitoneum pushed a large amount of CO₂ into the abdominal blood vessels, exceeding the gas exchange capacity of the lung and causing CO₂ bubble formation in the left-side cardiac system. These two cases indicate that intraoperative transesophageal echocardiography can reduce the influence of CO₂ embolism during laparoscopic tumor surgery by early diagnosis of the embolism and provide helpful information to establish a list of differential diagnoses of postoperative complications.

Cerebral arterial gas embolism proven by computed tomography following transthoracic echocardiography using bubble contrast

A 75 year-old male developed features of an acute stroke following bubble contrast echocardiography, which was shown on emergent computed tomography scanning to be a result of cerebral arterial gas embolism (CAGE) to the left middle cerebral artery. Ischaemic stroke symptoms have previously been reported as a rare complication of bubble contrast echocardiography. Radiologically proven CAGE from bubble contrast echocardiography had not been reported at the time this case occurred. Immediate provision of 100% oxygen and administration of hyperbaric oxygen are recommended treatments for CAGE and were associated with a substantial recovery for this patient.

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.

Cerebral air embolism following an endoscopic variceal ligation: A case report

BACKGROUND

Cerebral air embolism (CAE) is a rare but potentially devastating complication of endoscopic procedures. Only 3 cases, to our knowledge, have been reported.

CASE PRESENTATION

A 50-year-old female patient presented with hepatitis C virus-related hepatic cirrhosis, emergency endoscopy and endoscopic variceal ligation was performed in an awakened state. CAE occurred during procedure, the patient passed away the next day in the intensive care unit.

CONCLUSIONS

CAE is a rare but potentially devastating complication in endoscopic procedures. We need more preventive tools and treatments.

Cerebral Artery Gas Embolism Following Navigational Bronchoscopy

INTRODUCTION

Cerebral artery gas embolism (CAGE) is a rare but serious adverse event with potentially devastating neurologic sequelae. Bronchoscopy is a frequently performed procedure but with only a few reported cases of CAGE.

METHODS

We report the first documented case of CAGE associated with electromagnetic navigational bronchoscopy.

RESULTS

A 61-year-old man with a left lower lobe nodule underwent electromagnetic navigational bronchoscopy. The target lesion underwent transbronchial biopsy, brushing and an end-procedure lavage. Following the procedure, he developed seizures, evidence of hypoxic injury and cerebral edema, and air emboli were seen on computed tomography imaging. He then underwent treatment with hyperbaric oxygen with a full and complete neurologic recovery. Review of other cases reported in the literature suggests improved neurologic outcomes with hyperbaric oxygen treatment.

CONCLUSIONS

Biopsy techniques performed during bronchoscopy and electromagnetic navigational bronchoscopy can result in CAGE. Comparison with other reported cases suggests improved neurologic outcomes in those treated with hyperbaric oxygen. Prompt recognition of this complication and timely treatment with hyperbaric oxygen are the cornerstones to recovery.

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.

Delayed hyperbaric oxygen therapy for air emboli after open heart surgery: case report and review of a success story

Background

The current case describes a rare diagnosis of iatrogenic air emboli after elective cardiopulmonary bypass that was successfully treated with delayed hyperbaric oxygen therapy, with good clinical evolution in spite of rare complications.

Case presentation

A 35 years old male was admitted to the intensive care unit (ICU) for post-operative management after being placed on cardiopulmonary bypass (CPB) for an elective ventricular septal defect closure and aortic valvuloplasty. The patient initially presented with pathologically late awakening and was extubated 17 h after admission. Neurologic clinical status after extubation showed global aphasia, mental slowness and spatio-temporal disorientation. The injected cerebral CT scan was normal; the EEG was inconclusive (it showed metabolic encephalopathy without epileptic activity); and the cerebral MRI done 48 h after surgery showed multiple small subcortical acute ischemic lesions, mainly on the left fronto- parieto- temporo-occipital lobes. He was taken for hyperbaric oxygen therapy (HOT) over 54 h after cardiac surgery. The first session ended abruptly after 20 min when the patient suffered a generalised tonico-clonic seizure, necessitating a moderately rapid decompression, airway management, and antiepileptic treatment. In total, the patient received 7 HOT sessions over 6 days. He demonstrated full neurological recovery at 4 weeks and GOS (Glasgow Outcome Scale) of 5 out of 5 even after a long delay in initial management. Convulsions are a rare complication of HOT either due to reperfusion syndrome or hyperoxic toxicity and can be managed. Prior imaging by MRI or tympanic paracentesis (myringotomy) should not add further delay of treatment.

Conclusion

HOT should be initiated upon late awakening and/or neurologic symptoms after CPB heart surgery, after exclusion of formal counter-indications, even if the delay exceeds 48 h.

Central line complications

Central venous access is a common procedure performed in many clinical settings for a variety of indications. Central lines are not without risk, and there are a multitude of complications that are associated with their placement. Complications can present in an immediate or delayed fashion and vary based on type of central venous access. Significant morbidity and mortality can result from complications related to central venous access. These complications can cause a significant healthcare burden in cost, hospital days, and patient quality of life. Advances in imaging, access technique, and medical devices have reduced and altered the types of complications encountered in clinical practice; but most complications still center around vascular injury, infection, and misplacement. Recognition and management of central line complications is important when caring for patients with vascular access, but prevention is the ultimate goal. This article discusses common and rare complications associated with central venous access, as well as techniques to recognize, manage, and prevent complications.

Effects of high-pressure oxygen therapy on brain tissue water content and AQP4 expression in rabbits with cerebral hemorrhage

To investigate the effects of different atmosphere absolutes (ATA) of high-pressure oxygen (HPO) on brain tissue water content and Aquaporin-4 (AQP4) expression in rabbits with cerebral hemorrhage. 180 New Zealand white rabbits were selected and randomly divided into normal group (n = 30), control group (n = 30) and cerebral hemorrhage group (n = 120), and cerebral hemorrhage group was divided into group A, B, C and D with 30 rabbits in each group. The groups received 1.0, 1.8, 2.0 and 2.2 ATA of HPO treatments, respectively. Ten rabbits in each group were killed at first, third and fifth day to detect the brain tissue water content and change of AQP4 expression. In cerebral hemorrhage group, brain tissue water content and AQP4 expression after model establishment were first increased, then decreased and reached the maximum on third day (p < 0.05). Brain tissue water content and AQP4 expression in control group and cerebral hemorrhage group were significantly higher than normal group at different time points (p < 0.05). In contrast, brain tissue water content and AQP4 expression in group C were significantly lower than in group A, group B, group D and control group (p < 0.05). In control group, AQP4-positive cells significantly increased after model establishment, which reached maximum on third day, and positive cells in group C were significantly less than in group A, group B and group D. We also found that AQP4 expression were positively correlated with brain tissue water content (r = 0.719, p < 0.05) demonstrated by significantly increased AQP4 expression along with increased brain tissue water content. In conclusion, HPO can decrease AQP4 expression in brain tissue of rabbits with cerebral hemorrhage to suppress the progression of brain edema and promote repairing of injured tissue. 2.0 ATA HPO exerts best effects, which provides an experimental basis for ATA selection of HPO in treating cerebral hemorrhage.