Temperature rises in the round window caused by various light sources during insertion of rigid endoscopes: an experimental animal study.

OBJECTIVES: The instruments used in endoscopic surgery include rigid endoscopes of different diameters and angles, sources of light and monitors. In this study, we explored temperature rises in the round window caused by insertion of rigid endoscopes of different diameters into the middle ear; the endoscopes were fitted with different light sources. DESIGN: An experimental animal study. SETTING: We subjected seven guinea pigs to simulate otological surgery at room temperature. We monitored body temperatures, along with temperature rises caused by the use of 0° rigid endoscopes of diameters 3 or 4 mm, fitted with light sources including a halogen light, a light-emitting diode (LED) and a xenon light. Data were collected every second from a sensor placed in the round window. PARTICIPANTS: An experimental study on 7 guinea pigs. MAIN OUTCOME MEASURES: Rise of the temperature on round window. RESULTS: Rigid endoscopes caused the temperature of the tympanum to rise when xenon and halogen light sources were used, regardless of endoscope diameter. However, the temperature rise was less when a LED light source was employed. CONCLUSION: The endoscopic instruments used in middle ear surgery caused the temperature of the round window to rise. The rise varied with endoscope diameter and the type of light source used.

Evaluation of preoperative and postoperative S-100B levels in children with chronic adenotonsillar hypertrophy: preliminary results.

OBJECTIVES: Upper air obstruction leads hypoxia, it is also known that S-100B levels increase by glial activations indicate cerebral hypoxic injury. This study aimed to evaluate the preoperative and postoperative S-100B levels in children with chronic adenotonsillar hypertrophy. PATIENTS AND METHODS: The study comprised 40 patients with indications for tonsillectomy and/or adenoidectomy following a diagnosis of chronic adenotonsillar hypertrophy and 40 age-gender matched control patients. Blood samples were taken from the patients preoperatively and at four weeks postoperatively. Preoperative and postoperative serum S-100B levels were analyzed. RESULTS: The serum S-100B levels in the preoperative period were found to be significantly higher compared to those of the control group (p < 0.05). The S-100B levels were significantly decreased in the postoperative period (p < 0.05). CONCLUSIONS: The development of chronic adenotonsillar hypertrophy would play a role in increased S-100B levels. This indicates that neuronal damage would exists in patients with chronic adenotonsillar hypertrophy.