000K utf8 1100 2022$c2022-08-08 1500 eng 2050 urn:nbn:de:hbz:465-20240108-100207-7 2051 10.1177/08850666221119716 3000 Suleiman, Aiman 3010 Baedorf-Kassis, Elias N. 3010 Berra, Lorenzo 3010 Chamadia, Shubham 3010 Eikermann, Matthias 3010 Hammer, Maximilian 3010 Johnson-Akeju, Oluwaseun 3010 Munoz-Acuna, Ronny 3010 Rumyantsev, Sandra 3010 Santer, Peter 3010 Schaefer, Maximilian S. 3010 Wachtendorf, Luca J. 4000 Effects of Ketamine Infusion on Breathing and Encephalography in Spontaneously Breathing ICU Patients [Suleiman, Aiman] 4209 Background: Preclinical studies suggest that ketamine stimulates breathing. We investigated whether adding a ketamine infusion at low and high doses to propofol sedation improves inspiratory flow and enhances sedation in spontaneously breathing critically ill patients. Methods: In this prospective interventional study, twelve intubated, spontaneously breathing patients received ketamine infusions at 5 mcg/kg/min, followed by 10 mcg/kg/min for 1 h each. Airway flow, pressure, and esophageal pressure were recorded during a spontaneous breathing trial (SBT) at baseline, and during the SBT conducted at the end of each ketamine infusion regimen. SBT consisted of one-minute breathing with zero end-expiratory pressure and no pressure support. Changes in inspiratory flow at the pre-specified time points were assessed as the primary outcome. Ketamine-induced change in beta-gamma electroencephalogram power was the key secondary endpoint. We also analyzed changes in other ventilatory parameters respiratory timing, and resistive and elastic inspiratory work of breathing. Results: Ketamine infusion of 5 and 10 mcg/kg/min increased inspiratory flow (median, IQR) from 0.36 (0.29-0.46) L/s at baseline to 0.47 (0.32-0.57) L/s and 0.44 (0.33-0.58) L/s, respectively ( p = .013). Resistive work of breathing decreased from 0.4 (0.1-0.6) J/l at baseline to 0.2 (0.1-0.3) J/l after ketamine 10 mcg/kg/min ( p = .042), while elastic work of breathing remained unchanged. Electroencephalogram beta-gamma power (19-44 Hz) increased compared to baseline ( p < .01). Conclusions In intubated, spontaneously breathing patients receiving a constant rate of propofol, ketamine increased inspiratory flow, reduced inspiratory work of breathing, and was associated with an “activated” electroencephalographic pattern. These characteristics might facilitate weaning from mechanical ventilation. 4950 https://doi.org/10.1177/08850666221119716$xR$3Volltext$534 4950 https://nbn-resolving.org/urn:nbn:de:hbz:465-20240108-100207-7$xR$3Volltext$534 4961 https://duepublico2.uni-due.de/receive/duepublico_mods_00077505 5051 610 5550 brain activity 5550 critical care ventilation 5550 ICU sedation 5550 inspiratory flow 5550 Ketamine infusion 5550 mechanical ventilation 5550 spontaneous breathing trial 5550 weaning from ventilator