Effects of Total Intravenous Anesthesia and Low- and High-Flow Anesthesia Implementation on Middle Ear Pressure

The middle ear is an air-filled lacuna in the temporal bone. Inhaled anesthetic agents increase the pressure of this lacuna. Therefore, attention must be paid in choosing not only anesthetic agents but also anesthetic method.

This study compared the effects of high-flow total intravenous anesthesia (TIVA) and low- and high-flow desflurane anesthesia on middle ear pressure.

Randomized prospective double-blind study.

In this retrospective double-blind study, 90 patients (20-65 years old) scheduled to undergo elective thyroidectomies were divided into three randomized anesthesia groups: high-flow desflurane (Group I), low-flow desflurane (Group II), and high-flow TIVA (propofol, remifentanil) (Group III). The hemodynamic and respiratory parameters and tympanometry were measured before induction (T1), 10 minutes after intubation (T2), 10 minutes before the end of the operation (T3), and 5 (T4), 10 (T5), 15 (T6), and 30 (T7) minutes after the operation.

No statistically significant differences were found in the age, gender, weight, height, body mass index, surgery duration, and anesthetic duration (p > 0.05). There were no statistically significant differences at T1, T3, T4, T5, T6, and T7 (p > 0.007), but there was a significant difference at T2 (p < 0.001), with Groups II and III having lower pressure than Group I (p < 0.001).

The high-flow desflurane group had higher postinduction middle ear pressure values. Therefore, low-flow anesthesia and TIVA can be used more safely in middle ear surgeries, provided that a well-equipped anesthetic device and appropriate monitoring conditions are available.