Subjects
hernias
DERMOID CYSTS, MINOR, CNS INFECTIONS
The study protocol was approved by the ethics committee of the Ludwig-Maximilians University Munich. This sample size was chosen in order to additionally perform a correlation analysis of the impedance and volume curves. A sample size of 19 participants was calculated. Taking into account 15% possible dropouts, 23 patients were included. Written informed consent was obtained from the parents or legal guardians before participation in the study. Pediatric patients receiving balanced general anesthesia (for induction: intravenous application of propofol 1% and sufentanil or alfentanil, for maintenance: inhalation application of sevoflurane) without using neuromuscular blockers as part of elective surgery, with a chest circumference between 36 and 70 cm and a tidal volume > 20 ml were included. A PEEP of 5 mbar was chosen for all patients. The ventilation pressure was chosen to achieve a tidal volume of 6 ml/kg/body weight. The highest driving pressure required was 11 mbar, the lowest 5 mbar. Patients with a permanent or temporary pacemaker, defibrillator or other implanted medical devices that deliver electrical energy were excluded. Patients in whom the application of the electrode belt could have been affected by wound care or infections in the chest area and female patients in whom pregnancy could not be excluded were not included. Measurements were taken during minor procedures such as closure of inguinal hernias, circumcision, orchidopexy or removal of dermoid cysts. The duration of sedation was shorter than one hour in all patients.