Comparison of the effects of desflurane and sevoflurane on middle ear pressure: a randomized controlled clinical trial

Acute Intraoperative Tympanic Membrane Rupture in Patient Anesthetized With Desflurane Without Nitrous Oxide: A Case Report

We report a case of acute intraoperative tympanic membrane (TM) rupture in a patient anesthetized with desflurane without N2O. The patient was undergoing endoscopic retrograde cholangiopancreatography (ERCP) to treat ascending cholangitis. TM rupture is known to occur with N2O but has not been reported in the literature with the use of inhaled volatile anesthetics without N2O. We suspect that several factors contributed to this complication, including prone positioning, a remote history of ear trauma, and the selection of desflurane as the maintenance anesthetic as opposed to a vapor with a higher blood-gas partition coefficient.

Effects of General Anaesthesia on the Middle Ear Pressure

OBJECTIVE

Inhalation agents can have different effects on the middle ear pressure (MEP). We aimed to investigate the effect of sevoflurane and desflurane, the agents used in patients who do not have any ear pathology and who undergo surgery under general anaesthesia, on MEP.

METHODS

Fifty adult patients who were scheduled to undergo inguinal hernia and lower extremity surgery were included in our study. All patients were aged between 20 and 60 years and belonged to the American Society of Anesthesiologists (ASA) I-III class. Patients were divided into two groups, according to the inhalation agent administered for the surgery: sevofluran, Group S (n=25); and desfluran, Group D (n=25). Anaesthetic agents, intraoperative end tidal carbon dioxide and airway pressures were recorded. The MEP was measured for both ears preoperatively, at the intraoperative 5th, 10th, 15th minutes, and at the postoperative 10th and 30th minutes.

RESULTS

The MEP at the intraoperative 10th minute was significantly higher in Group D compared to Group S. In Group D, the MEP increased significantly at the intraoperative 10th and 15th minutes, and postoperative 30th minute, compared to preoperative values. In Group S, the MEP increased significantly at the postoperative 10th minute, compared to preoperative values.

CONCLUSION

We found that desflurane increases the MEP during the intraoperative and postoperative period, compared to sevoflurane.

Do Intubation Devices Affect Middle Ear Pressure Dynamics?

Our study aimed to investigate the effects of different intubation devices on middle ear pressure (MEP) dynamics by evaluating MEP during stages of anesthesia.Sixty-one consecutive patients were randomly assigned to 2 groups: the classical endotracheal intubation group and the Baska Mask (a new laryngeal mask [LMA]) group. All patients received the same anesthesia protocol. The right and left MEP values of the patients were measured and recorded preoperatively, during the induction of anesthesia, at the time of intubation and at 5th minute of anesthesia.In group 1, the pressure values measured in the right ear during anesthesia induction, at the time of intubation and at 5th minute of anesthesia were 10.97 ± 27.06, 16.77 ± 29.40, and 21.64 ± 90.31, respectively, compared to left ear values of 8.61 ± 26.39, 18.77 ± 37.84, and 38.61 ± 56.96 daPa, respectively. In group 2, MEP values measured in the right ear during anesthesia induction, at the time of intubation, and at 5th minute of anesthesia were 9.53 ± 20.43, 22.30 ± 41.50, and 20.60 ± 46.85 daPa, respectively, compared to left ear values of -4.26 ± 25.17, 6.20 ± 26.56, and 30.30 ± 65.17 daPa, respectively. MEP was statistically significantly increased in the classical endotracheal intubation group compared to the LMA group.We found that the increase in pressure is lower in patients receiving LMA compared to classical endotracheal intubation. The Baska Mask LMA is recommended in selected patients to prevent complications of MEP elevation.