Air Embolism during Arthrography for Developmental Dysplasia of the Hip
The patient was an 8-month-old female infant with left DDH. She had been diagnosed with dislocation of the left hip at another hospital at the age of 3 months, and she was treated with a Pavlik harness for 4 weeks. However, her left hip was not reduced, and she was admitted to our institution at the age of 8 months. The anteroposterior radiograph showed that the left femoral head was completely dislocated and had shifted to the lateral and proximal side (). She did not have the abnormality at the time of birth; in addition, no past illness, allergy, or family history of DDH were noted. At our institution, she underwent closed reduction under general anesthesia. Her hip joint was reduced; however, it was unstable, and the femoral head was easily dislocated when we decreased the hip abduction angle down to 60°.\nSubsequently, arthrography was performed to verify the reduction and to analyze the obstructive factors and afferent nature of the femoral head. First, the legs were maintained in the frog-leg position, and then, a 23-gauge Cathelin needle was inserted in the central part of the femoral proximal epiphyseal line using the anterior approach. After confirming that blood was not aspirated, 1 mL of air was injected to confirm that the Cathelin needle was accurately sited in the joint; subsequently, we injected 1 mL of the contrast medium.\nTwo minutes after air injection, the endtidal carbon dioxide (ETCO2) concentration decreased suddenly from 37 mmHg to 19 mmHg, and the blood oxygen concentration decreased from 99% to 97% (). The anesthesiologist noticed the change, and he increased oxygenation from 33% oxygen to 100% under observation. The blood oxygen concentration and ETCO2 concentration gradually improved and returned to normal values after 2 min and 12 min, respectively. Other vital signs such as blood pressure and pulse rate remained unchanged. An arthrogram showed good reduction of the femoral head. Plaster cast fixation was performed at an abduction angle of approximately 70°. After the operation, she was placed in a plaster cast, abduction brace, and Pavlik harness, for 4 weeks each. At the latest examination performed at the age of 4 years, the patient had not experienced any recurrence of dislocation.