From the Research
Yes, hearing loss can occur after cardiac surgery and cardiopulmonary bypass (CPB), with a reported incidence of approximately 5.05 cases per 1000 operations in adults, according to the most recent and highest quality study 1. This complication is relatively uncommon but significant, and the hearing loss is typically sensorineural in nature, which may be temporary or permanent. Several mechanisms contribute to this risk, including:
- Microemboli traveling to the inner ear's blood vessels
- Hypoperfusion during surgery
- Ototoxic medications used perioperatively
- Inflammatory responses triggered by CPB The risk increases with longer bypass times, higher levels of hemodilution, and in patients with pre-existing hearing problems or vascular disease. Some key points to consider:
- The majority of cases of hearing loss were mild in the adult population (56.6%) 1
- In the pediatric population, 59.2% of hearing loss cases had moderate or worse hearing loss 1
- The hearing loss most often affects the higher frequencies, over 6000 Hz 1
- Early audiological evaluation is recommended if symptoms occur, as prompt intervention may help prevent permanent damage in some cases Patients should be informed of this potential complication before surgery, and those experiencing hearing changes postoperatively should report them promptly to their healthcare providers. It is also worth noting that the exact mechanisms of hearing loss after CPB are not fully understood and may involve multiple factors, including microembolism, hypoperfusion, and ototoxicity 2, 3, 4, 5.