Fatal air embolism following penetrating lung trauma: an autopsy study

Fatal systemic (paradoxical) air embolism diagnosed by postmortem funduscopy

Air embolism is often unrecognized and underreported. Published case reports or case series describe only rare fundal examinations of retinal air emboli (RAE)-a distinctive sign of systemic air embolism. We report an infant, found unresponsive at home, who died in the emergency department after unsuccessful resuscitative efforts. Before the autopsy, diagnostic RAE were recognized and imaged during postmortem funduscopy. Postmortem radiography and an autopsy confirmed systemic (paradoxical) air embolism due to inflicted abdominal and thoracic blunt force injuries. While a few descriptions and illustrations of RAE occur in case reports, we found no published photographic images of RAE in infants, children, or adults. This case report describes and photographically documents classic RAE associated with fatal systemic (paradoxical) air embolism. Complementing postmortem radiography and judicious autopsy techniques, the detection of RAE can aid pathologists in diagnosing systemic air embolism.

Western Trauma Association critical decisions in trauma: resuscitative thoracotomy

BACKGROUND

In the past three decades, there has been a significant clinical shift in the performance of resuscitative thoracotomy (RT), from a nearly obligatory procedure before declaring any trauma patient deceased to a more selective application of RT. We have sought to formulate an evidence-based guideline for the current indications for RT after injury in the patient.

METHODS

The Western Trauma Association Critical Decisions Committee queried the literature for studies defining the appropriate role of RT in the trauma patient. When good data were not available, the Committee relied on expert opinion.

RESULTS

There are no published PRCT and it is not likely that there will be; recommendations are based on published prospective observational and retrospective studies, as well as expert opinion of Western Trauma Association members. Patients undergoing cardiopulmonary resuscitation (CPR) on arrival to the hospital should be stratified based on injury and transport time. Indications for RT include the following: blunt trauma patients with less than 10 minutes of prehospital CPR, penetrating torso trauma patients with less than 15 minutes of CPR, patients with penetrating trauma to the neck or extremity with less than 5 minutes of prehospital CPR, and patients in profound refractory shock. After RT, the patient's intrinsic cardiac activity is evaluated; patients in asystole without cardiac tamponade are declared dead. Patients with a cardiac wound, tamponade, and associated asystole are aggressively treated. Patients with an intrinsic rhythm following RT should be treated according to underlying primary pathology. Following several minutes of such treatment as well as generalized resuscitation, salvageability is reassessed; we define this as the patient's ability to generate a systolic blood pressure of greater than 70 mm Hg with an aortic cross-clamp if necessary.

CONCLUSION

The success of RT approximates 35% for the patient arriving in shock with a penetrating cardiac wound and 15% for all patients with penetrating wounds. Conversely, patient outcome is relatively poor when RT is performed for blunt trauma, 2% survival for patients in shock and less than 1% survival for patients with no vital signs. Patients undergoing CPR on arrival to the hospital should be stratified based on injury and transport time to determine the utility of RT. This algorithm represents a rational approach that could be followed at trauma centers with the appropriate resources; it may not be applicable at all hospitals caring for the injured. There will be patient, personnel, institutional, and situational factors that may warrant deviation from the recommended guideline. The annotated algorithm is intended to serve as a quick bedside reference for clinicians.

Arterielle Luftembolie nach Polytraumatisierung bei Sturz aus dem 10. Stock

We report about the case of a 20-year-old patient who fell from the tenth floor. The patient suffered multiple injuries and systemic gas embolism. He survived his injuries despite CPR, massive transfusion, development of ARDS and SIRS with minimal neurological deficit. The possible pathogenesis of the systemic gas embolism as well as the therapy are discussed. Besides stabilizing the circulation with i.v. fluids, blood transfusion and catecholamine therapy, the use of hyperbaric oxygenation was the decisive therapeutic measure.

Emergency department thoracotomy for the critically injured patient: Objectives, indications, and outcomes

In the past three decades there has been a significant clinical shift in the performance of emergency department thoracotomy (EDT), from a nearly obligatory procedure before declaring any trauma patient to select patients undergoing EDT. The value of EDT in resuscitation of the patient in profound shock but not yet dead is unquestionable. Its indiscriminate use, however, renders it a low-yield and high-cost procedure. Overall analysis of the available literature indicates that the success of EDT approximates 35% in the patient arriving in shock with a penetrating cardiac wound, and 15% for all penetrating wounds. Conversely, patient outcome is relatively poor when EDT is done for blunt trauma; 2% survival in patients in shock and less than 1% survival with no vital signs. Patients undergoing CPR upon arrival to the emergency department should be stratified based upon injury and transport time to determine the utility of EDT. The optimal application of EDT requires a thorough understanding of its physiologic objectives, technical maneuvers, and the cardiovascular and metabolic consequences.

Systemic air embolism after intercostal chest drain insertion and positive pressure ventilation in chest trauma

Systemic air embolism is a potentially lethal often unrecognised complication of severe chest trauma. We present a case of delayed diagnosis of cerebral air embolism in a patient with severe thoracic trauma. The initiation of positive pressure ventilation, systemic hypotension, intraparenchymal chest drains and aerial transfer to an intensive care unit were all factors contributing to the development of systemic air embolism. The common clinical features, diagnostic tests and management of systemic air emboli are discussed.

Lung isolation for the prevention of air embolism in penetrating lung trauma. A case report

PURPOSE

To illustrate a new airway and ventilatory management strategy for patients with unilateral penetrating lung injury. Emphasis is placed on avoiding positive pressure ventilation (PPV)-induced systemic air/gas embolism (SAE) through traumatic bronchiole-pulmonary venous fistulas.

CLINICAL FEATURES

A 14-yr-old male, stabbed in the left chest, presented with hypovolemia, left hemopneumothorax, an equivocal acute abdomen, and no cardiac or neurological injury. In view of the risk of SAE, we did not ventilate the left lung until any fistulas, if present, had been excised. After pre-oxygenation, general anesthesia was induced and a left-sided double-lumen tube (DLT) was placed to allow right-lung ventilation. Bronchoscopy was performed. The surgeons performed a thorascopic wedge resection of the lacerated lingula. Upon completion of the repair, two-lung ventilation was instituted while the ECG, pulse oximetry, PETCO2, and blood pressure were monitored. Peak inflation pressure was increased slowly and was well tolerated up to 50 cm H2O. The patient's intravascular status was maintained normal.

CONCLUSION

Patients with lung trauma are at risk of developing SAE when their lungs are ventilated with PPV. In a unilateral case, expectant non-ventilation of the injured lung until after repair is recommended.

Can one lung ventilation prevent air embolism in the lung injury victim?

The current literature indicates that patients with hilar lung injury who are receiving positive pressure ventilation are at risk for systemic air embolism, but no studies have yet tested an alternative to the current management: immediate thoracotomy and hilar clamping. We wanted to demonstrate that one lung ventilation of the uninjured lung protects against the formation of arterial air embolism in the presence of contralateral hilar lung injury.In 6 juvenile swine, the right bronchus was selectively ventilated, and ultrasound of the abdominal aorta was used to detect air emboli. The hilum of the left lung was stabbed with a scalpel; after a brief period of monitoring to detect air emboli, the tip of the endotracheal tube was withdrawn into the trachea and the left lung ventilated.Air emboli were detected in 2 animals. The air emboli did not form while the lung was isolated, but they did appear immediately when the endotracheal tube was withdrawn into the trachea. Air was also noted in the chambers of the heart and coronary arteries, and led to fibrillation and death.One lung ventilation appears to protect against arterial air embolism in unilateral hilar lung injury. (Curr Surg 57:349-353)

Gas Embolism: Part II. Arterial Gas Embolism and Decompression Sickness

Gas emboli syndromes are known to occur in many different settings, and they may result in life-threatening emergencies. Venous gas embolization was discussed previously in Part I of this review. Gas emboli that gain access to the arterial circulation or that result from exposures to decreased ambient pressures in the environment are discussed in Part II. The prevalence of arterial gas emboli and decompression sickness are likely not as high as for venous gas emboli. Most cases are preventable, and prompt treatment is frequently effective. Once present, gas bubbles generally distribute themselves throughout the body based on the relative blood flow at the time, thus making the nervous system, heart, lung, and skin the primary organ systems involved. Both mechanical and biophysical effects lead to intravascular and extracellular alterations that result in tissue injury. The clinical manifestations of these disorders are varied, and a high index of suspicion in the appropriate settings will aid health care providers in prompt recognition of these problems and allow timely intervention with specific therapy. Management of arterial gas emboli and decompression sickness is similar, with a focus on hyberbaric chamber therapy and intermittent hyperoxygenation. Recompression schedules in current use have withstood the test of time. Research continues to refine our understanding of these diseases and to optimize the treatment regimens available.

Morbidity and Mortality After Traumatic Pneumonectomy: The Effect of Compromised Oxygenation and Cardiac Function

I describe the pathophysiological and hemodynamic events that occur after an emergency pneumonectomy for trauma and how they impact on subsequent mortality. Four patients were identified as requiring an emergency right pneumonectomy for trauma at a level 1 Urban Trauma Center within a 39-month period. A retrospective review of their hospital course served as the basis for our analysis. Three patients sustained gunshot wounds and one patient was a victim of blunt trauma. Hemodynamic data were available for three patients who survived more than 24 hours. All patients presented in shock and required massive transfusion. One patient died in the operating room due to air embolism and shock. After pneumonectomy, there was an increase in pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) more than 2 times normal, which coincided with a decrease in stroke volume, cardiac output, and right and left ventricular stroke work (RVSW/LVSW). The RVSW gradually increased to above normal levels by postoperative day 5, whereas the LVSWI remained below normal. Adult respiratory distress syndrome (ARDS) developed in all patients early in the postoperative period. There was evidence of oxygen delivery (DO2) dependent of oxygen consumption (VO2) and the DO2 remained below normal despite inotrope administration. The remaining three patients died 7 to 13 days after surgery due to various combinations of ARDS, cardiac failure, and sepsis. Until we have better methods to decrease PAP selectively, traumatic pneumonectomy should be avoided if possible, especially when it involves the right side or is associated with a contralateral lung injury. Early operative intervention and control of the pulmonary hilum may lessen the severity of shock. The hemodynamic changes that occur after pneumonectomy for trauma becomes additive in the presence of ARDS. This combination results in inadequate cardiac function, oxygen transport, and, ultimately, death.

Elevation of serum creatine kinase in divers with arterial gas embolization

BACKGROUND

Arterial gas embolism due to pulmonary barotrauma and the resultant cerebral gas embolism are catastrophic complications of diving. Previous studies have only rarely noted evidence of gas embolism to noncranial sites.

METHODS

Among 142 persons with diving-related injuries evaluated between January 1982 and July 1991, we identified 29 who had arterial gas embolism and who underwent biochemical studies indicative of muscle injury. Of the 29 patients, 4 were excluded because cardiopulmonary resuscitation had been performed and 3 were excluded because the duration of their dives met or exceeded standard limits set for dives not requiring staged decompression. The outcome at the time of hospital discharge in the remaining 22 patients was correlated with clinical factors and the results of biochemical studies. We also studied 22 subjects after uncomplicated dives and 11 patients who had sustained blunt trauma.

RESULTS

All the patients with diving-associated gas embolism had elevated serum creatine kinase activity (normal, < or = 175 U per liter); the values were markedly elevated (> 900 U per liter) in 14. The MB isoenzyme of creatine kinase was detected in the serum of 13 of 20 patients in whom it was measured and was > or = 4 percent of total creatine kinase activity in 6 patients. In three patients electrocardiography showed myocardial injury. Changes in serum creatine kinase activity of similar magnitude were not present in the subjects who had uncomplicated dives or in the patients with blunt trauma. Thirteen patients recovered fully, four had minor residual neurologic deficits, three were severely impaired, and two died. Logistic-regression analysis revealed a significant correlation between peak serum creatine kinase values and clinical outcome.

CONCLUSIONS

Biochemical evidence of muscle injury is frequently found after diving-associated arterial gas embolism. The correlation between serum creatine kinase activity and outcome suggests that serum creatine kinase is a marker of the size and severity of arterial gas embolism.

Anesthetic problems. Venous air embolism, airway difficulties, and massive transfusion

Perioperative anesthetic complications require the coordinated efforts of both the surgical and anesthesia teams. These complications, or their sequelae, have significant influence on the care of the patient in the preoperative, intraoperative, and postoperative periods.

Systemic arterial air embolism in penetrating lung injury

Systemic arterial air embolism is frequently unrecognized as a cause of death among patients with isolated penetrating lung injury. Between 1975 and 1983 at Parkland Memorial Hospital, the complication of systemic arterial air embolism developed in 9 patients with penetrating lung injury (six gunshots and three stabbings). Eight patients were either in profound shock or experienced cardiac arrest and all were intubated and on positive-pressure ventilation, frequently on a manual resuscitator bag before or at the time of diagnosis. The diagnosis was made by direct visualization of air in the coronary vessels in all 9 patients, and in 3 air was also aspirated from the left ventricular apex and aortic root. In addition, 5 patients had clinically significant hemoptysis. At operation, only an isolated injury to the lung was found in 7 of the 9 patients. Arterial air embolism is a highly lethal complication; 6 of our patients died, a mortality rate of 66%. Thus, it clearly behooves us to be more alert to the possible occurrence of this complication among all victims of penetrating chest trauma. We must accept that systemic arterial air embolism is an established complication of penetrating lung injury and must recognize that it occurs much more frequently than has been previously reported. Prompt diagnosis coupled with aggressive efforts at cardiopulmonary resuscitation is crucial for successful management of patients with air embolism.