End-organ protection in cardiac surgery

Mortality and morbidity postcardiac surgery with cardiopulmonary bypass (CPB) remain relative stable over the last decades, while the number of patients with increased comorbidity and more complex cardiac disease increases. Nevertheless, end-organ dysfunction and/or failure remain an issue. Multiple perioperative variables, such as non-optimal oxygen delivery, manipulation of the aorta, hyperlactatemia, type of anesthesia, surgical procedure and myocardial protection can be hold responsible for end-organ failure postcardiac surgery. However, it becomes more and more evident that also pre-existing factors, such as metabolic syndrome, renal insufficiency, hypertension, stroke and infection exacerbate mortality and morbidity. Unfortunately, these predisposing risk factors cannot be influenced perioperatively. Therefore, therapy should focus on controlling perioperative variables that, in combination with the predisposing factors, will further exacerbate organ dysfunction. In order to achieve this, more emphasis should be given to a patient-specific, goal-directed perfusion approach. This review will mainly focus on the impact of perioperative variables.

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

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

[Retrograde cavernous sinus air embolism after central venous catheter removal]

Air embolism is a rare, but occasionally fatal complication of peripheral and central venous catheterization. We present a case of an 89-year-old female, who had a central venous catheter placed in her right jugular vein during the perioperative period for right femoral subtrochanteric fracture. On the day following her operation, level of consciousness worsened a few minutes after the catheter was removed. CT scan showed air bubbles in bilateral cavernous sinuses and brachiocephalic vein. Administration of 100% oxygen was started, and she regained consciousness a few hours later, finally air bubbles disappeared on a CT scan performed 10 hours after onset. Air embolism should be taken into consideration when treating venous catheters, and appropriate O₂ administration and radiological examinations must be performed immediately if level of consciousness or vital signs deteriorate.

[Hyperbaric oxygen therapy for air embolism complicating computed tomography (CT)-guided needle marking of the lung]

Preoperative computed tomography( CT)-guided marking with a short hook wire for small sized lung tumors has become popular along with the spread of thoracoscopic surgery. Systemic arterial air embolism is a very rare but potentially fatal complication. The patient was a 79-year-old man who was found to have a mixed ground glass opacity shadow on chest CT. Almost immediately after marking, he lost consciousness and complete atrio-ventricular (AV) block was found on the electrocardiogram (ECG) monitor. Brain CT showed intravascular air bubbles in the right frontal lobe. Two hours later, his conscious level was recovered completely but remained left hemiplegia. Five hours later, he was transported to another hospital for hyperbaric oxygen therapy. After 3 episodes of the treatment, left hemiplegia recovered with slight sense disorder in the left little finger. When neurologic findings are remained after air embolism, hyperbaric oxygen therapy should be arranged immediately.

Coronary air embolism

The case report of acute coronary episode caused by air embolism associated with the removal of central vascular access, published in "Anaesthesiology Intensive Therapy"1/2012 aroused much interest [1]. Iatrogenic gas emboli are rare, albeit dramatic complications of therapeutic interventions,which result in persistent neurological symptoms in over 40% of cases [2].

Cerebral venous air embolism treated with hyperbaric oxygen: a case report

We present a case of cerebral venous gas embolism. Our patient made a complete neurological recovery after hyperbaric oxygen therapy (HBOT). The principles of HBOT, compressing and eliminating air bubbles and decreasing Β-2 integrin function, thus improving microcirculation, can only be beneficial in a situation where neurological damage is likely. Retrograde cerebral venous gas embolism is a less well recognised variant of gas embolism than the arterial variant. Its existence as a different entity is better recognised in the forensic medicine and radiology literature than in other disciplines. There is evidence in the literature of patients dying from this complication and others seemingly experiencing very little effect. This case report highlights this condition, to encourage others to look out for it and report outcomes, and to serve as a reminder that peripheral lines may be a potential cause of gas embolism, although the portal of air entry in our case remains uncertain.

Massive air embolism from continuous venovenous haemofiltration causing electromechanical dissociation in a cardiac surgical patient

Venous air embolism is a rare but life-threatening complication of continuous venovenous haemofiltration. We report a case of massive venous air embolism associated with haemofiltration in a 75-year-old man after complicated cardiac surgery. Haemofiltration circuitry and air detector alarms are not infallible and air embolism should be considered in patients receiving such therapy who develop cardiopulmonary instability. We discuss our early intervention, which focused on restoration of the circulation, prevention of further air entry, retrieval of air and supportive care. The use of transoesophageal echocardiography for diagnosis of air embolism and to aid the insertion of a pulmonary artery catheter for air aspiration was essential for management.

Complete neurological recovery after systemic air embolism during endoscopic retrograde cholangiopancreatography

Systemic air embolisms are a rare but often a fatal complication of endoscopic retrograde cholangiopancreatography (ERCP). Only few cases have been reported in scientific studies. This paper concerns a case of a systemic air embolism that occurred during endoscopic sphincterotomy for gallstone removal in a 79-year-old-woman and discusses possible mechanisms. The basic vital and neurologic signs of the woman deteriorated abruptly towards the end of the procedure. It was believed to be an air embolism and an urgent transthoracic echocardiography was ordered which confirmed the etiological diagnosis. Supportive measures were initiated: she was administered 100% oxygen, she was placed head down, left lateral position and fluid resuscitation was started to increase venous pressure. We considered hyperbaric oxygen therapy for neurological injury but, despite the severe initial presentation, she had a complete clinical recovery with only conservative treatment. Present experience stresses the importance of the awareness of this uncommon complication: a close vigilance of the anesthetists during ERCP is critical to ensure early diagnosis and a timely intervention.

Air in the heart: what should one do?

Air embolism is a serious and frequently underrecognized complication of vascular access device placement. Improper precautions during vascular catheter insertion result in inadvertent introduction of air into the vasculature. Systemic embolization into the cerebral, pulmonary, and coronary circulations can be catastrophic. We present a case of intracardiac air embolism after placement of a central venous catheter managed conservatively.

Observation of increased venous gas emboli after wet dives compared to dry dives

INTRODUCTION

Testing of decompression procedures has been performed both in the dry and during immersion, assuming that the results can be directly compared. To test this, the aim of the present paper was to compare the number of venous gas bubbles observed following a short, deep and a shallow, long air dive performed dry in a hyperbaric chamber and following actual dives in open water.

METHODS

Fourteen experienced male divers participated in the study; seven performed dry and wet dives to 24 metres' sea water (msw) for 70 minutes; seven divers performed dry and wet dives to 54 msw for 20 minutes. Decompression followed a Bühlmann decompression procedure. Immediately following the dive, pulmonary artery bubble formation was monitored for two hours. The results were graded according to the method of Eftedal and Brubakk.

RESULTS

All divers completed the dive protocol, none of them showed any signs of decompression sickness. During the observation period, following the shallow dives, the bubbles increased from 0.1 bubbles per cm ² after the dry dive to 1.4 bubbles per cm ² after the wet dive. Following the deep dives, the bubbles increased from 0.1 bubbles per cm ² in the dry dive to 2.4 bubbles per cm ² in the wet dive. Both results are highly significant (P = 0.0001 or less).

CONCLUSIONS

The study has shown that diving in water produces significantly more gas bubble formation than dry diving. The number of venous gas bubbles observed after decompression in water according to a rather conservative procedure, indicates that accepted standard decompression procedures nevertheless induce considerable decompression stress. We suggest that decompression procedures should aim at keeping venous bubble formation as low as possible.

A case of hepatic portal venous gas as a complication of endoscopic balloon dilatation

The development of hepatic portal venous gas (HPVG) is rare but it might be associated with serious disease and poor clinical outcome. Recently, several iatrogenic causes of HPVG have been reported. HPVG as a complication of endoscopic balloon dilatation is a previously unreported event. We experienced a case of HPVG after endoscopic balloon dilatation in a 31 yr-old man with pyloric stricture due to corrosive acids ingestion. The patient was treated conservatively with fluid resuscitation, antibiotics and Levin tube with natural drainage. Five days later, the follow-up CT scan showed spontaneous resolution of HPVG. This case reminded us the clinical importance and management strategy of HPVG. We report here a case of iatrogenic HPVG with a review of relevant literature.

Hyperbaric oxygen treatment to eliminate a large venous air embolism: a case study

Gas embolism, the entry of gas into vascular structures, can result in serious morbidity and death. It is an inadvertent clinical problem, but it also occurs in non-clinical environments. Gas embolisms result from procedures performed in almost all clinical specialties, thus making it a problem about which all clinicians should be aware. In most cases, gas embolism is air embolism, although it can result from the introduction of gases such as carbon dioxide, nitrous oxide and nitrogen. Gas embolism takes two forms, venous and arterial, distinguished by the mechanism of gas entry and the site where the emboli ultimately lodge. Techniques used to eliminate embolisms including administration of 100% oxygen, placing the patient in lateral decubitus, and Trendelenburg position for no longer than 10 minutes, removing the embolism with a catheter, surfactants and hyperbaric oxygen therapy (HBO2T). For venous gas embolisms surgical removal is recommended, while for arterial embolisms, HBO2T is highly recommended. Here we report on a patient who inadvertently received a venous infusion of 150 ml air resulting in a major embolism, and who underwent HBO2T, recovered well, and suffered no adverse events. This result suggests that it is important to consider HBO2T as a recommended application for patients with venous embolisms.

Crisis checklists for the operating room: development and pilot testing

BACKGROUND

Because operating room crises are rare events, failure to adhere to critical management steps is common. We sought to develop and pilot a tool to improve adherence to lifesaving measures during operating room crises.

STUDY DESIGN

We identified 12 of the most frequently occurring operating room crises and corresponding evidence-based metrics of essential care for each (46 total process measures). We developed checklists for each crisis based on a previously defined method, which included literature review, multidisciplinary expert consultation, and simulation. After development, 2 operating room teams (11 participants) were each exposed to 8 simulations with random assignment to checklist use or working from memory alone. Each team managed 4 simulations with a checklist available and 4 without. One of the primary outcomes measured through video review was failure to adhere to essential processes of care. Participants were surveyed for perceptions of checklist use and realism of the scenarios.

RESULTS

Checklist use resulted in a 6-fold reduction in failure of adherence to critical steps in management for 8 scenarios with 2 pilot teams. These results held in multivariate analysis accounting for clustering within teams and adjusting for learning or fatigue effects (11 of 46 failures without the checklist vs 2 of 46 failures with the checklist; adjusted relative risk = 0.15, 95% CI, 0.04-0.60; p = 0.007). All participants rated the overall quality of the checklists and scenarios to be higher than average or excellent.

CONCLUSIONS

Checklist use can improve safety and management in operating room crises. These findings warrant broader evaluation, including in clinical settings.

Massive air embolism in a Fontan patient

Most institutions performing cardiopulmonary bypass for congenital heart disease patients use an integrated hard shell cardiotomy and venous reservoir attached to an oxygenator. It is of paramount importance that the integrated reservoir be vented so as not to cause pressurization. A pressurized sealed cardiotomy has been reported to occur secondary to issues with vacuum assisted venous drainage systems as well as improper venting in general. We report a case of air embolus caused by retrograde propulsion of air through the venous line secondary to a pressurized cardiotomy reservoir in a patient with Fontan circulation. The mechanism of cardiotomy pressurization is described, and the scenario simulated in a mock circuit.

Case reports: hyperbaric oxygen therapy for the treatment of cerebral air embolism

Cerebral air embolism is one of the most deleterious disorders that may affect divers, but it is also a possible complication of surgeries and medical procedures. We report our experience with iatrogenic cerebral air embolism and hyperbaric oxygen treatment.

Systemic arterial air embolism after percutaneous lung biopsy

Systemic arterial air embolism is a rarely encountered but much feared complication of percutaneous lung biopsy. We present a comprehensive review of iatrogenic air embolism post-lung biopsy, a complication that is often suboptimally managed. This review was inspired by our own institutional experience and we use this to demonstrate that excellent outcomes from this complication can be seen with prompt treatment using hyperbaric oxygen chamber therapy, after initial patient stabilization has been achieved. Pathophysiology, clinical features, and risk factors are reviewed and misconceptions regards venous versus arterial air embolism are examined. An algorithm is provided for radiologists to ensure suspected patients are appropriately managed with more favourable outcomes.

Electrocardiogram and X-ray findings associated with iatrogenic pulmonary venous gas embolism

Iatrogenic venous gas embolism (VGE) has been described in cases of patients with hemodialysis catheters and other thoracic central lines. When VGE is present, it may lead to large gas bubbles in the right heart or pulmonary circulation. We reviewed a case of a 52-year-old male hemodialysis patient who inadvertently received an unknown amount of air through a faulty connection in his line during hemodialysis treatment. The patient was symptomatic with chest pain and was found to have an ECG indicative of acute right heart strain and an unusual bulging of his right mediastinum on X-ray. An emergency consult was called for hyperbaric oxygen therapy (HBO2T) due to the known indications for therapy. The patient had a full recovery after HBO2T and had complete relief of his chest pain after compression. Repeat decubitus chest X-ray and ECG post-HBO2T showed resolution of the mediastinal bulge, and ECG had reverted to the patient's baseline tracing. Iatrogenic pulmonary VGE may be diagnosed with the aid of ECG and X-ray findings when correlated with historical and other clinical elements. HBO2 treatment success may be correlated with reversal of ECG and X-ray findings in patients with clinical improvement.

Simple active air evacuation procedure for right ventricular failure caused by intracoronary air embolism

In cardiac surgical cases such as valve replacement, right ventricular failure caused by intracoronary air embolism sometimes occurs after aortic declamping and during weaning from cardiopulmonary bypass (CPB). The details are reported of a de-airing method which involves simply rotating the arterial cannula towards the base of the heart, with no need for a particular circuit. This method was used in ten patients who, following open-heart surgery, suffered postoperative right ventricular failure due to air embolism in the right coronary artery that did not respond to other de-airing methods. The technique resolved the problem in all patients, who were quickly weaned from CPB and ultimately discharged. Rotation of the arterial cannula may represent a simple means of resuscitating patients who have suffered right ventricular dysfunction that is unrelieved by other, conventional methods.

A case report of cerebral air embolism after esophagogastroduodenoscopy: diagnosis and management in the emergency department

BACKGROUND

Esophagogastroduodenoscopy (EGD) is a rare cause of cerebral air embolism (CAE). To our knowledge, there are only eight previously reported such cases in the history of the procedure.

OBJECTIVE

To identify clinical causes of CAE that can present to the emergency department (ED) and to understand the appropriate management of CAE.

CASE REPORT

A 71-year-old man presented with new-onset left-sided hemiparesis and dysarthria 2h after undergoing an outpatient EGD. The patient was diagnosed with CAE in the ED after undergoing a computed tomography scan of the brain without contrast.

CONCLUSION

The diagnosis of CAE is based on a thorough history and obtaining urgent radiographic imaging of the brain. The definitive treatment of CAE involves hyperbaric oxygen.

Decompression illness

Decompression illness is caused by intravascular or extravascular bubbles that are formed as a result of reduction in environmental pressure (decompression). The term covers both arterial gas embolism, in which alveolar gas or venous gas emboli (via cardiac shunts or via pulmonary vessels) are introduced into the arterial circulation, and decompression sickness, which is caused by in-situ bubble formation from dissolved inert gas. Both syndromes can occur in divers, compressed air workers, aviators, and astronauts, but arterial gas embolism also arises from iatrogenic causes unrelated to decompression. Risk of decompression illness is affected by immersion, exercise, and heat or cold. Manifestations range from itching and minor pain to neurological symptoms, cardiac collapse, and death. First-aid treatment is 100% oxygen and definitive treatment is recompression to increased pressure, breathing 100% oxygen. Adjunctive treatment, including fluid administration and prophylaxis against venous thromboembolism in paralysed patients, is also recommended. Treatment is, in most cases, effective although residual deficits can remain in serious cases, even after several recompressions.

Simultaneous left ventricular and cerebral artery air embolism after computed tomographic-guided transthoracic needle biopsy of the lung

Air embolism is rare and potentially fatal. Its early recognition and prompt treatment can help to prevent life-threatening sequelae. Herein, we report the case of a 75-year-old man who underwent a computed tomographic-guided lung biopsy of a left-lower-lobe pulmonary nodule. A few minutes after the procedure, he experienced numbness and weakness in his right hand; this lasted for approximately 10 minutes and resolved on its own. Similar symptoms developed in his left hand and subsided in 5 minutes. His speech then became garbled. An urgent computed tomographic scan of the head showed no acute abnormality. Review of the chest computed tomographic scans that were performed during the biopsy revealed 10 cc of air in the left ventricular cavity. The patient was placed on 100% forced inspiratory oxygen and was kept in the Trendelenburg position on his left side. After 4 hours, computed tomography revealed that the air had been absorbed into the circulation. The patient had no residual neurologic deficits. In addition to reporting this case, we discuss possible causes of air embolism and the management of the condition after percutaneous lung biopsy.