Sudden Coma and Quadriplegia in a Hemodialysis Patient

Discussion

In hemodialysis-related air embolism, air bubbles may arise from incomplete priming or a loosened tube connection and then enter the extracorporeal circuit (1). Nowadays, life-threatening air embolism during hemodialysis is rare due to the addition of air bubble detectors and air chamber to modern hemodialysis machines. However, air embolism may still occur during placement of a hemodialysis catheter, with accidental disconnection, or at its removal (1). Air embolism is due to the suicidal cutting of catheter in this patient.

There are three migration pathways of air bubbles (2): retrogradely to the cerebral venous system, to pulmonary circulation, and paradoxically to systemic circulation or coronary arteries. The distribution of the cerebral air embolism indicates retrograde migration mechanism in this patient. The retrograde air embolism could be facilitated by the patient’s upright posture and valvular insufficiency and may cause severe neurologic sequelae: alerted consciousness, seizure, focal neurologic deficit, and brain edema (2). Most of these signs are compatible with our patient. No trapped air was found in the pulmonary vessels or right ventricular outflow tract in the computer tomography pulmonary angiogram, which excluded the prominent air migration to pulmonary circulation in this patient. The paradoxical arterial air embolism, which is associated with massive air in pulmonary circulation or cardiac septal defect, may cause myocardial infarction. However, the following ST-elevation myocardial infarction (STEMI) in this patient may have been unrelated to paradoxical arterial air embolism due to infarction in single coronary territory (V2–V6), preexisting atherosclerosis, and lack of cardiac septal defect.

In terms of management, further entry of gas should be prevented after the diagnosis of air embolism is considered. Supportive care with oxygen and intravenous fluid should be offered. Oxygen therapy may reduce the size of emboli, and intravenous fluid may increase the venous pressure and prevent further entry of gas (3). Finally, our patient underlines that late-life depression, especially in groups with ESKD, should be identified and managed with proper support (4).