Venous Air Embolism Research Articles

Finding the bubble: atypical and unusual extrapulmonary air in the chest

ObjectiveTo describe the radiologic findings of extrapulmonary air in the chest and to review atypical and unusual causes of extrapulmonary air, emphasizing the importance of the diagnosis in managing these patients. ConclusionIn this article, we review a series of cases collected at our center that manifest with extrapulmonary air in the thorax, paying special attention to atypical and uncommon causes. We discuss the causes of extrapulmonary according to its location: mediastinum (spontaneous pneumomediastinum with pneumorrhachis, tracheal rupture, dehiscence of the bronchial anastomosis after lung transplantation, intramucosal esophageal dissection, Boerhaave syndrome, tracheoesophageal fistula in patients with esophageal tumors, bronchial perforation and esophagorespiratory fistula due to lymph-node rupture, and acute mediastinitis), pericardium (pneumopericardium in patients with lung tumors), cardiovascular (venous air embolism), pleura (bronchopleural fistulas, spontaneous pneumothorax in patients with malignant pleural mesotheliomas and primary lung tumors, and bilateral pneumothorax after unilateral lung biopsy), and thoracic wall (infections, transdiaphragmatic intercostal hernia, and subcutaneous emphysema after lung biopsy).

Whole-body vibration preconditioning reduces the formation and delays the manifestation of high-altitude-induced venous gas emboli.

What is the central question of this study? Is performing a 30-min whole-body vibration (WBV) prior to a continuous 90-min exposure at 24,000ft sufficient to prevent venous gas emboli (VGE) formation? What is the main finding and its importance? WBV preconditioning significantly reduces the formation and delays the manifestation of high-altitude-induced VGE. This study suggests that WBV is an effective strategy in lowering decompression stress. Rapid decompression may give rise to formation of venous gas emboli (VGE) and resultantly, increase the risk of sustaining decompression sickness. Preconditioning aims at lowering the prevalence of VGE during decompression. The purpose of this study was to investigate the efficacy of whole-body vibration (WBV) preconditioning on high-altitude-induced VGE. Eight male subjects performed, on separate days in a randomised order, three preconditioning strategies: 40-min seated-rest (control), 30-min seated-rest followed by 150 knee-squats performed over a 10-min period (exercise) and 30-min WBV proceeded by a 10-min seated-rest. Thereafter, subjects were exposed to an altitude of 24,000ft (7315 m) for 90min whilst laying in a supine position and breathing 100% oxygen. VGE were assessed ultrasonically both during supine rest (5-min intervals) and after three fast, unloaded knee-bends (15-min intervals) and were scored using a 5-grade scale and evaluated using the Kisman Integrated Severity Score (KISS). There was a significant difference in VGE grade (P<0.001), time to VGE manifestation (P=0.014) and KISS score following knee-bends (P=0.002) across protocols, with a trend in KISS score during supine rest (P=0.070). WBV resulted in lower VGE grades (median (range), 1 (0-3)) and KISS score (2.69±4.56a.u.) compared with control (2 (1-3), P=0.002; 12.86±8.40a.u., P=0.011) and exercise (3 (2-4) , P<0.001; 22.04±13.45a.u., P=0.002). VGE were detected earlier during control (15±14min, P=0.024) and exercise (17±24min, P=0.032) than WBV (54±38min). Performing a 30-min WBV prior to a 90-min continuous exposure at 24,000ft both delays the manifestation and reduces the formation of VGE compared with control and exercise preconditioning.

Delayed cerebral infarction due to cerebral venous air emboli after cardiac arrest

Delayed cerebral infarction due to cerebral venous air emboli after cardiac arrest

Outcomes after semisitting and lateral positioning in large vestibular schwannoma surgery: A single-center comparison

ObjectiveThe semisitting position (SSP) and lateral position (LP) in vestibular schwannoma (VS) surgery each have advantages and disadvantages, and which position is superior overall is debatable. Our objective was to determine the optimal position for surgical treatment of VSs with a diameter ≥3 cm. MethodsWe retrospectively evaluated consecutive patients with a large VS treated between January 2010 and July 2020. Patients were grouped by surgical position and analyzed. ResultsWe enrolled 259 patients (LP group, n = 156; SSP group, n = 103). The resection extent was not significantly different between the SSP (gross-total resection [GTR], n = 89 [88.1%], near-total resection [NTR], n = 10 [9.9%], subtotal resection [STR], n = 2 [2.0%]) and LP (GTR, n = 125 [80.1%]; NTR, n = 24 [15.4%]; STR, n = 7 [4.5%]) groups. The rate of GTR with facial nerve (FN) functional preservation was higher in the SSP group than in the LP group (P = 0.014) at eight days after the operation. However, during follow-up (SSP group median, 31.5 months; LP group median, 19.5 months), there was no significant between-group difference in FN functional preservation. Two patients in the SSP group required conversion to the LP due to severe intraoperative venous air embolism (VAE). ConclusionCompared with the LP, the SSP did not produce significantly better FN outcomes in patients with a large VS. The duration of surgery was significantly longer in SSP cases than in LP cases. Given the risk of VAE associated with the SSP, the selection of the optimal surgical position should be made with caution on an individual basis.

Anesthetic challenges involved in successful resuscitation of a child from cardiac arrest secondary to massive hemorrhage and possible venous air embolism while undergoing fronto-orbital advancement surgery for metopic craniosynostosis

A one year 3 month old child undergoing fronto-orbital advancement surgery for metopic craniosynostosis had severe bleeding when the surgeon attempted to remove bone flap. Head-end elevation was given at the surgeon’s request to reduce bleeding. Immediately there was a drastic fall in end tidal carbon dioxide (ETCO) and arterial saturation (SpO). Considering air embolism, fraction of inspired oxygen (FiO) was increased to 100% and the surgeon filled the field with saline and covered the area with wet gauze. The operating table was leveled. The child continued to deteriorate with the cardiac rhythm changing to pulseless electrical activity and asystole. Incremental bolus doses of adrenaline, blood products transfusion, fluid bolus and infusion of inotropes were given. Chest compression was not done as the endotracheal tube was fixed to the chest of the patient. Tube dislodgement without access to the head-end of the patient would have been a disaster. The child became hemodynamically stable, the surgery continued and the child was extubated the next day. Other than focal seizures which responded to levetiracetam, the child had no neurological deficits.

Epilepsy and Anesthesia

Epilepsy is one of the most common neurological conditions with the worldwide prevalence as high as 1%.1,2,3 Epilepsy can be classified into three categories: (1) generalized epilepsies, (2) focal epilepsies, and (3) a new group of combined generalized and focal epilepsies.8 Treatment of epilepsy begins with the initiation of an antiepileptic drug (AED). Patients who continue to seizure despite adequate therapy with two AEDs may require surgical interventions.1 There are many different surgical procedures that may be used in the management of epilepsy, including temporal lobectomy, extratemporal resections, hemispherectomy, vagal nerve stimulation (VNS), and deep brain stimulation (DBS). Epilepsy surgery often requires intraoperative localization of the epileptic focus. This can be achieved with intraoperative electrocorticography (ECoG). Many of our anesthetic drugs interfere with the intraoperative EEG recording, and a knowledge of their properties is required to provide a safe anesthetic. Anesthesia for epilepsy surgery can be done in one of three ways: (1) awake with local anesthesia, (2) general anesthesia, and (3) the asleep-awake-asleep technique. Complications including hemorrhage, venous air embolism, and status epilepticus may occur and require prompt treatment by the anesthesiologist. A thorough knowledge of neuroanesthesia is required to provide appropriate care to the epileptic patient. This review contains 3 figures, 4 tables, and 51 references. Keywords: Awake craniotomy, electrocorticography, epilepsy, neuroanesthesia, perioperative care, status epilepticus, treatment, temporal lobe surgery, intraoperative electrocorticography

Compressions for Portal Vein Air Embolism Evacuation

Laparoscopic entry into the abdomen with subsequent insufflation can be achieved via an open or closed approach. A risk that is often overlooked as a result of its rarity is a venous air embolism (VAE) from carbon dioxide (CO 2 ) insufflation. Although both closed and open techniques of entry into the abdomen contribute to an extremely low risk for VAE, when the effects are clinically significant the mortality rate has been reported to be as high as 28%. In this report we present a case of a 64-year-old female who underwent a closed approach for entry into the abdomen for elective hepatic cystectomy, who subsequently went into cardiopulmonary arrest and was found to have imaging findings suggestive of VAE localized to the portal vein. Successful management decisions presented in this case report will serve as possible options for physicians to employ when encountering a similar intraoperative complication. J Curr Surg. 2021;11(2):42-45 doi: https://doi.org/10.14740/jcs436

Prompt intervention can avert catastrophic outcome of portal venous air embolism during ERCP

Prompt intervention can avert catastrophic outcome of portal venous air embolism during ERCP

Hyperoxic Effects on Decompression Strain During Alternating High and Moderate Altitude Exposures.

INTRODUCTION: In fighter aircraft, long-duration high-altitude sorties are typically interrupted by refueling excursions to lower altitude. In normoxia, excursions to moderate cabin altitude may increase the occurrence of venous gas emboli (VGE) at high cabin altitude. The aim was to investigate the effect of hyperoxia on VGE and decompression sickness (DCS) during alternating high and moderate altitude exposure.METHODS: In an altitude chamber, 13 healthy men were exposed to three different conditions: A) 90 min at 24,000 ft (7315 m) breathing normoxic gas (54% O₂; H-NOR); B) 90 min at 24,000 ft breathing hyperoxic gas (90% O₂; H-HYP); and C) three 30-min exposures to 24,000 ft interspersed by two 30-min exposures to 18,000 ft (5486 m) breathing 90% O₂ (ALT-HYP). VGE occurrence was evaluated from cardiac ultrasound imaging. DCS symptoms were rated using a scale.RESULTS: DCS occurred in all conditions and altogether in 6 of the 39 exposures. The prevalence of VGE was similar in H-NOR and H-HYP throughout the exposures. During the initial 30 min at 24,000 ft, the prevalence of VGE was similar in ALT-HYP as in the other two conditions, whereas, after the first excursion to 18,000 ft, the VGE score was lower in ALT-HYP than in H-NOR and H-HYP.DISCUSSION: Hyperoxic excursions from 24,000 to 18,000 ft reduces VGE occurrence, presumably by facilitating diffusive gas exchange across the bubble surfaces, increasing the share of bubble content contributed by oxygen. Still, the excursions did not abolish the DCS risk.Ånell R, Grönkvist M, Gennser M, Eiken O. Hyperoxic effects on decompression strain during alternating high and moderate altitude exposures. Aerosp Med Hum Perform. 2021; 92(4):223230.

Venous air embolism during stifle arthroscopy in a horse

SummaryThis case report describes venous air embolism as a complication of stifle joint arthroscopy in a 16‐year‐old French Saddle Pony. Carbon dioxide was used to achieve joint distension during the procedure and accidentally entered the vasculature, causing the embolism. The diagnosis was based on a sudden onset of laboured breathing, tachycardia and dropping end‐tidal carbon dioxide (PE'CO2) and was confirmed by arterial blood gas analysis showing hypercapnia and large PE'CO2—arterial partial pressure of carbon dioxide (PaCO2) difference. This complication was treated by increasing the fraction of inspired oxygen (FIO2) and immediate ceasing of further gas insufflation. The horse suffered no further complications. To our knowledge, this is the first publication reporting this complication during arthroscopy in a horse. Awareness of this complication should be raised between veterinarians performing arthroscopies when using gas as the distending agent. A high index of suspicion and early recognition of the embolism can improve chances for full and unremarkable recoveries.

Buscando la burbuja: aire torácico extrapulmonar atípico e inusual

ObjectiveTo describe the radiologic findings of extrapulmonary air in the chest and to review atypical and unusual causes of extrapulmonary air, emphasizing the importance of the diagnosis in managing these patients. ConclusionIn this article, we review a series of cases collected at our center that manifest with extrapulmonary air in the thorax, paying special attention to atypical and uncommon causes. We discuss the causes of extrapulmonary according to its location: mediastinum (spontaneous pneumomediastinum with pneumorrhachis, tracheal rupture, dehiscence of the bronchial anastomosis after lung transplantation, intramucosal esophageal dissection, Boerhaave syndrome, tracheoesophageal fistula in patients with esophageal tumors, bronchial perforation and esophagorespiratory fistula due to lymph-node rupture, and acute mediastinitis), pericardium (pneumopericardium in patients with lung tumors), cardiovascular (venous air embolism), pleura (bronchopleural fistulas, spontaneous pneumothorax in patients with malignant pleural mesotheliomas and primary lung tumors, and bilateral pneumothorax after unilateral lung biopsy), and thoracic wall (infections, transdiaphragmatic intercostal hernia, and subcutaneous emphysema after lung biopsy).

Open chest and pericardium facilitate transpulmonary passage of venous air emboli.

Transpulmonary passage of air emboli can lead to fatal brain- and myocardial infarctions. We studied whether pigs with open chest and pericardium had a greater transpulmonary passage of venous air emboli than pigs with closed thorax. We allocated pigs with verified closed foramen ovale to venous air infusion with either open chest with sternotomy and opening of the pleura and pericardium (n=8) or closed thorax (n=16). All pigs received a five-hour intravenous infusion of ambient air, starting at 4-6mL/kg/h and increased by 2mL/kg/h each hour. We assessed transpulmonary air passage by transesophageal M-mode echocardiography and present the results as median with inter-quartile range (IQR). Transpulmonary air passage occurred in all pigs with open chest and pericardium and in nine pigs with closed thorax (56%). Compared to pigs with closed thorax, pigs with open chest and pericardium had a shorter to air passage (10minutes (5-16) vs. 120minutes (44-212), P<.0001), a smaller volume of infused air at the time of transpulmonary passage (12mL (10-23) vs.170mL (107-494), P<.0001), shorter time to death (122minutes (48-185) vs 263minutes (248-300, P=.0005) and a smaller volume of infused air at the time of death (264mL (53-466) vs 727mL (564-968), P=.001). In pigs with open chest and, infused air and time to death correlated strongly (r=0.95, P=.001). Open chest and pericardium facilitated the transpulmonary passage of intravenously infused air in pigs.

Variability in venous gas emboli following the same dive at 3,658 meters

Exposure to a reduction in ambient pressure such as in high-altitude climbing, flying in aircrafts, and decompression from underwater diving results in circulating vascular gas bubbles (i.e., venous gas emboli [VGE]). Incidence and severity of VGE, in part, can objectively quantify decompression stress and risk of decompression sickness (DCS) which is typically mitigated by adherence to decompression schedules. However, dives conducted at altitude challenge recommendations for decompression schedules which are limited to exposures of 10,000 feet in the U.S. Navy Diving Manual (Rev. 7). Therefore, in an ancillary analysis within a larger study, we assessed the evolution of VGE for two hours post-dive using echocardiography following simulated altitude dives at 12,000 feet. Ten divers completed two dives to 66 fsw (equivalent to 110 fsw at sea level by the cross correction method) for 30 minutes in a hyperbaric chamber. All dives were completed following a 60-minute exposure at 12,000 feet. Following the dive, the chamber was decompressed back to altitude for two hours. Echocardiograph measurements were performed every 20 minutes post-dive. Bubbles were counted and graded using the Germonpré and Eftedal and Brubakk method, respectively. No diver presented with symptoms of DCS following the dive or two hours post-dive at altitude. Despite inter- and intra-diver variability of VGE grade following the dives, the majority (11/20 dives) presented a peak VGE Grade 0, three VGE Grade 1, one VGE Grade 2, four VGE Grade 3, and one VGE Grade 4. Using the cross correction method for a 66-fsw dive at 12,000 feet of altitude resulted in a relatively low decompression stress and no cases of DCS.

Acclimatization to diving: a systematic review

Multiday hyperbaric exposure has been shown to reduce the incidence of decompression sickness (DCS) of compressed-air workers. This effect, termed acclimatization, has been addressed in a number of studies, but no comprehensive review has been published. This systematic review reports the findings of a literature search. PubMed, Ovid Embase, The Cochrane Library and Rubicon Research Repository were searched for studies reporting DCS incidence, venous gas embolism (VGE) or subjective health reports after multiday hyperbaric exposure in man and experimental animals. Twenty-nine studies fulfilled inclusion criteria. Three epidemiological studies reported statistically significant acclimatization to DCS in compressed- air workers after multiday hyperbaric exposure. One experimental study observed less itching after standardized simulated dives. Two human experimental studies reported lower DCS incidence after multiday immersed diving. Acclimatization to DCS has been observed in six animal species. Multiday diving had less consistent effect on VGE after hyperbaric exposure in man. Four studies observed acclimatization while no statistically significant acclimatization was reported in the remaining eight studies. A questionnaire study did not report any change in self-perceived health after multiday diving. This systematic review has not identified any study suggesting a sensitizing effect of multiday diving, and there is a lack of data supporting benefit of a day off diving after a certain number of consecutive diving days. The results suggest that multiday hyperbaric exposure probably will have an acclimatizing effect and protects from DCS. The mechanisms causing acclimatization, extent of protection and optimal procedure for acclimatization has been insufficiently investigated.

Treat Venous Air Embolism Induced Acute Hypoxemic Respiratory Failure during Retinal Surgery by ECMO (V-V Mode).

Treat Venous Air Embolism Induced Acute Hypoxemic Respiratory Failure during Retinal Surgery by ECMO (V-V Mode).

Application of a new hyperbaric oxygen therapy protocol in patients with arterial and venous gas embolism due to hydrogen peroxide poisoning

Hydrogen peroxide (H2O2) ingestion can cause vascular gas embolism (GE). Hyperbaric oxygen therapy (HBO2) is known to improve neurological abnormalities in patients with arterial gas embolism (AGE). Previously, HBO2 based on the U.S. Navy Table 6 diving protocol has been adopted for treating AGE and preventing the progression of portal venous GE, caused by H2O2 ingestion, to AGE. However, the indication and protocol for HBO2 have not been established for GE related to H2O2 ingestion. Herein, we describe a case in which GE caused by H2O2 ingestion was treated using HBO2 with a short protocol. A 69-year-old female patient presented with abdominal pain, vomiting, and transient loss of consciousness after ingesting 35% H2O2. Computed tomography revealed gastric wall and portal venous gas. She was administered an HBO2 protocol with 2.8-atmosphere absolute (ATA) compression for 45 minutes. This was followed by a 2.0-ATA treatment for 60 minutes with a five-minute air break, after which all gas bubbles disappeared. After HBO2 treatment, brain magnetic resonance imaging revealed focal cytotoxic edema lesions; however, the patient was discharged without additional symptoms.

Fatal venous air embolism during lumbar spondylolisthesis surgery

Fatal venous air embolism during lumbar spondylolisthesis surgery

Awake surgery in sitting position for chronic subdural hematoma.

Chronic subdural hematoma (CSDH) is a common pathology in neurosurgery, especially in the elderly patients, and its incidence is likely to double in the next decade. Considering various features of CSDH and the procedure itself, a sitting position may retain the best characteristics of classic positioning, while offering additional comfort for both the patient and the surgeon. The aim of this study was to describe the technical aspects of this procedure in the sitting position, to evaluate safety and discuss the benefits and shortcomings of this modification. This study included a series of 55 patients surgically treated for CSDH in a sitting position at our department between December 2017 and September 2019, representing all the patients operated on during the study period by a single surgeon. Bilateral hematomas were present in 19 patients. Outcomes, during the 6-month follow-up period, were defined as good (CSDH and symptoms resolved) or poor (lethal outcome or reoccurrence). All complications were noted, with emphasis on pneumocephalus, and complications related to the sitting position: tension pneumocephalus, venous air embolism, and compression nerve injury. Complications previously associated with the sitting position were not noted. The Glasgow Coma Scale and Markwalder Grading Scale scores improved significantly after the surgery (p < 0.001 and p = 0.018). Complications were noted in 17 patients (30.9%), and included 5 cerebrospinal fluid drainages, 3 hematoma reoccurrences, 2 wound infections, and 9 more single-occurring complications. The in-hospital mortality was 5.4% (3 out of 55 patients), while the overall mortality was 16.4% within the 6-month follow-up period. In our series, even the severely ill patients tolerated the position well. No complications associated with the sitting position were noted. Future studies should confirm the safety of this position and evaluate the potential advantages for both the patient and the surgeon.

An echo from the past: Building a Doppler repository for big data in diving research

Decompression sickness (DCS) remains a major operational concern for diving operations, submarine escape and high-altitude jumps. Aside from DCS symptoms, venous gas emboli (VGE) detected with ultrasound postdive are often used as a marker of decompression stress in humans, with a specificity of 100% even though the sensitivity is poor [1]. Being non-invasive, portable and non-ionizing, ultrasound is particularly suited to regular and repeated monitoring. It could help elucidate interand intra-subject variability in VGE and DCS susceptibility, but analyzing these recordings remains a cumbersome task [2].

A fully automated method for late ventricular diastole frame selection in post-dive echocardiography without ECG gating

Venous gas emboli (VGE) are often quantified as a marker of decompression stress on echocardiograms. Bubblecounting has been proposed as an easy to learn method, but remains time-consuming, rendering large dataset analysis impractical. Computer automation of VGE counting following this method has therefore been suggested as a means to eliminate rater bias and save time. A necessary step for this automation relies on the selection of a frame during late ventricular diastole (LVD) for each cardiac cycle of the recording. Since electrocardiograms (ECG) are not always recorded in field experiments, here we propose a fully automated method for LVD frame selection based on regional intensity minimization. The algorithm is tested on 20 previously acquired echocardiography recordings (from the original bubble-counting publication), half of which were acquired at rest (Rest) and the other half after leg flexions (Flex). From the 7,140 frames analyzed, sensitivity was found to be 0.913 [95% CI: 0.875-0.940] and specificity 0.997 [95% CI: 0.996-0.998]. The method’s performance is also compared to that of random chance selection and found to perform significantly better (p&lt;0.0001). No trend in algorithm performance was found with respect to VGE counts, and no significant difference was found between Flex and Rest (p&gt;0.05). In conclusion, full automation of LVD frame selection for the purpose of bubble counting in postdive echocardiography has been established with excellent accuracy, although we caution that high quality acquisitions remain paramount in retaining high reliability.