Pulmonary air embolism in severe head injury

Spontaneous Air Embolism Following Contrast Injection: A Diagnostic Challenge in a Post-COVID-19 Patient

A 72-year-old male with a complex medical history, including chronic obstructive pulmonary disease (COPD), hypertension, atrial fibrillation, and a recent COVID-19 infection, presented to the emergency department with shortness of breath and chest pain. Physical examination revealed stable vital signs but notable bilateral decreased air entry and diffuse wheezing. A computed tomography angiogram (CTA) of the chest confirmed a small to moderate volume of air embolism within the main pulmonary artery and right ventricle, with no evidence of pulmonary embolism. The air embolism was suspected to have been introduced during a contrast injection for the CT scan, as no other iatrogenic factors, recent invasive procedures, or history of lung trauma were present. Initial management included repositioning the patient to a supine position and administering 100% oxygen, which was critical in stabilizing his condition. Despite the ongoing symptoms of shortness of breath, the patient's condition improved with supportive care focused on managing COPD exacerbation. Spontaneous air embolism without decompression sickness or prior instrumentation is exceptionally rare, particularly in a post-COVID-19 patient, making this case notable. It highlights the critical need for prompt recognition, thorough evaluation, and appropriate management of air embolism in complex medical scenarios to prevent life-threatening complications. This case also underscores the importance of considering iatrogenic causes, such as contrast injection, in the differential diagnosis, especially following recent imaging studies.

Gas embolism and massive blunt force trauma to sea turtles entrained in hopper dredges in North and South Carolina, USA

Decompression sickness (DCS) has been described mainly in loggerhead turtles Caretta caretta bycaught in trawls and gillnets. Here we present cases of gas emboli (GE) in 8 green turtles Chelonia mydas and 2 Kemp's ridleys Lepidochelys kempii entrained in hopper dredges that were working at 8.8-15.2 m depths during shipping channel maintenance or beach renourishment activities. Turtle weights ranged from 2.2 to 6.7 kg. All were found alive with blunt force injuries from passage through the dredge and were taken to rehabilitation facilities. Four green turtles died or were euthanized within 24 h. Six turtles survived. Radiographic or ultrasonographic evidence of GE was detected in 4 turtles, including 3 mortalities. Computed tomography (CT) revealed perirenal and cervical GE in 4 turtles, including 1 mortality. No GE were detected in 2 of the survivors. Upon necropsy, GE were found in mesenteric vessels, the right atrium, and kidneys. Histopathology confirmed that tissues were in a good state of preservation without evidence of bacterial overgrowth or putrefactive gas formation. Death likely resulted primarily from massive tissue trauma from the dredge, but moderate GE could have led to DCS and complicated recovery. The surviving turtles weighed less than those that did not survive. Besides hypothesized stress/exercise-induced circulatory changes of blood through the lungs and pressure reduction of forced surfacing from depth, drastic pressure change within the dredge pipes before and after the pump could contribute to GE. Hopper dredge entrainment is an additional cause of GE and potential DCS in sea turtles.

Intraoperative Management of Large Resuscitation-Associated Venous Air Embolism (VAE) for Emergent Neurological Surgery

Venous air embolism (VAE) is a well-described phenomenon that may have life-threatening cardiopulmonary and neurological consequences. Accidental administration of air during resuscitation while using a rapid infuser is rare. Furthermore, there is a paucity of published data describing the intraoperative management of VAE during emergent nonseated neurological surgery. We report a 22-year-old previously healthy female who experienced a motor vehicle accident with severe facial and head trauma, and mixed subdural and epidural hematomas with an 8 mm midline shift. Computed tomography revealed significant air entrainment in the right heart and main pulmonary artery, with venous air tracking from the right axillary vein. Given her age, lack of preexisting cardiac comorbidities, hemodynamic stability, and critical cerebral herniation risk, further cardiac evaluation was deferred, and the patient was transferred to the operating room for emergent decompressive craniotomy. Intraoperatively, she experienced acute decrease in mean arterial pressure and end-expiratory carbon-dioxide with loss of pulse oximetry waveform concerning for obstructive VAE physiology. She was responsive to fluid resuscitation and epinephrine administration and did not experience any recurrence of obstructive VAE. This challenging case report describes positive neurologic and hemodynamic outcomes after resuscitation-associated VAE and cardiopulmonary collapse during emergency neurosurgery. Comprehensive evaluation of risk, urgency of procedure, and need for diagnostic monitoring and treatment should be personalized.

Delayed lethal pulmonary air embolism after a gunshot head injury

We present a case of a young male patient with a fatal pulmonary air embolism following a penetrating gunshot head injury. He suffered from severe head trauma including a laceration of the superior sagittal sinus. Operative neurosurgical intervention did not establish a watertight closure of the wounds. Eight days after the trauma, the patient suddenly collapsed and died after an attempt to mobilise him to the vertical. Forensic autopsy indicated pulmonary air embolism as the cause of death. Retrospectively, we postulate an entry of air to the venous system via the incompletely occluded wounds and the lacerated superior sagittal sinus while mobilisation to the vertical created a negative pressure in the dural sinus.

Intrahepatic gas at postmortem computed tomography: forensic experience as a potential guide for in vivo trauma imaging

BACKGROUND

Until August 2004 there were 106 forensic cases examined with postmortem multislice computed tomography (MSCT) and magnetic resonance (MR) imaging before traditional autopsy within the Virtopsy project. Intrahepatic gas (IHG) was a frequent finding in postmortem MSCT examinations. The aim of this study was to investigate its cause and significance.

METHODS

There were 84 virtopsy cases retrospectively investigated concerning the occurrence, location, and volume of IHG in postmortem MSCT imaging (1.25 mm collimation, 1.25 mm thickness). We assessed and noted the occurrence of intestinal distention, putrefaction, and systemic gas embolisms and the cause of death, possible open trauma, possible artificial respiration, and the postmortem interval. We investigated the relations between the findings using the contingency table (chi2 test) and the comparison of the postmortem intervals in both groups was performed using the t test in 79 nonputrefied corpses.

RESULTS

IHG was found in 47 cases (59.5%). In five of the cases, the IHG was caused or influenced by putrefaction. Gas distribution within the liver of the remaining 42 cases was as follows: hepatic arteries in 21 cases, hepatic veins in 35 cases, and portal vein branches in 13 cases; among which combinations also occurred in 20 cases. The presence of IHG was strongly related to open trauma with systemic gas. Pulmonary barotrauma as occurring under artificial respiration or in drowning also caused IHG. Putrefaction did not seem to influence the occurrence of IHG until macroscopic signs of putrefaction were noticeable.

CONCLUSIONS

IHG is a frequent finding in traumatic causes of death and requires a systemic gas embolism. Exceptions are putrefied or burned corpses. Common clinical causes such as necrotic bowel diseases appear rarely as a cause of IHG in our forensic case material.