Air Embolism: Diagnosis, Clinical Management and Outcomes

Abstract

Air embolism is a rare but potentially fatal complication of surgical procedures. Rapid recognition and intervention is critical for reducing morbidity and mortality. We retrospectively characterized our experience with air embolism during medical procedures at a tertiary medical center. Electronic medical records were searched for all cases of air embolism over a 25-year period; relevant medical and imaging records were reviewed. Sixty-seven air embolism cases were identified; the mean age was 59 years (range, 3-89 years). Ninety-four percent occurred in-hospital, of which 77.8% were during an operation/invasive procedure. Vascular access-related procedures (33%) were the most commonly associated with air embolism. Clinical signs and symptoms were related to the location the air embolus; 36 cases to the right heart/pulmonary artery, 21 to the cerebrum, and 10 were attributed to patent foramen ovale (PFO). Twenty-one percent of patients underwent hyperbaric oxygen therapy (HBOT), 7.5% aspiration of the air, and 63% had no sequelae. Mortality rate was 21%; 69% died within 48 hours. Thirteen patients had immediate cardiac arrest where mortality rate was 53.8%, compared to 13.5% (p = 0.0035) in those without. Air emboli were mainly iatrogenic, primarily associated with endovascular procedures. High clinical suspicion and early treatment are critical for survival.

Keywords: air embolus; angiography; embolization.

Figure 1

This image shows a computed tomography (CT) brain of a 50-year-old female in the medical intensive care unit who became unresponsive shortly after removal of an internal jugular line. CT brain (A–C) was performed showing gas within the right frontal lobe in distribution, suggesting an intravascular location (arrow, A and B), together with diffuse loss of gray-white matter differentiation, most prominently in the central deep nuclei (arrowhead). There was evidence of mass effect, with effacement of the basal cisterns (C), and the dense cerebellum sign (*) related to relative sparing of the cerebellar hemispheres.

Figure 2

CT imaging of a 20-year-old female with paraspinal tumor seen on axial contrast enhanced CT (A). She became profoundly hypotensive during spinal surgery for resection of this malignant nerve sheath tumor. Air was noted in an infusion bag. CT brain at baseline (B) was normal, revealing normal volume of cerebrospinal fluid (CSF) around the cerebral hemispheres (arrowheads). Serial CT studies of the brain performed over the coming days revealed progressively worsening cerebral edema. CT brain at three days (C) shows effacement of CSF and diffuse cerebral swelling. She was managed with hyperbaric oxygen treatment and an intracranial pressure monitor was placed. CT brain performed 19 months later showed essentially normal appearances of the brain (D), with return of normal CSF spaces (arrowheads). The patient recovered from the air embolism, but died 25 months later from metastatic disease.

Figure 3

Changes in end-tidal CO₂ monitoring during intraoperative air embolism from the anesthesia record of a 76-year woman undergoing hemicraniectomy for traumatic intracranial hemorrhage. Approximately 5 min after the cranium was opened, a sudden decrease in end-tidal CO₂ was noted (circled, curved arrow) followed by a rapid decrease in both the systolic (BPS) and diastolic (BPD) blood pressure (circled, straight arrow). Immediate measures were taken, including lowering the head and flooding the field with water. However, 3 min after the change in CO₂ was detected, the patient suffered a pulseless electrical activity (PEA) cardiac arrest, and expired 1 h later despite resuscitative measures.