Related Experiment Videos
The effect of positive end-expiratory pressure ventilation on propofol concentrations during general anesthesia in
Eri Takizawa1, Naomi Ito, Junko Ishizeki
1Department of Anesthesiology, Graduate School of Medicine, Gunma University, 3-39-22 Showa-machi, Maebashi 371-8511, Japan.
Abstract:
The present study investigated the effects of positive end-expiratory pressure (PEEP) on propofol concentrations in humans. Eleven patients undergoing elective surgery were enrolled in this study. Anesthesia was induced with propofol, then maintained using 60% nitrous oxide in oxygen, fentanyl 10-20 microg/kg and continuous infusion of propofol. Vecuronium was used to facilitate the artificial ventilation of the lungs. Propofol was administered to all subjects via target-controlled infusion to achieve a propofol concentration of 6.0 microg/mL at intubation and 2.0 microg/mL after intubation. Before, during and after PEEP level of 10 cmH(2)O, cardiac output (CO) and effective liver blood flow (LBF) was measured using indocyanine green as an indicator and blood propofol concentration was determined using high-performance liquid chromatography. Data are expressed as median and range. After PEEP of 10 cmH(2)O was applied, CO and effective LBF was significantly decreased from 5.5 (3.8-6.8) L/min to 4.5 (3.2-5.8) L/min (P < 0.05), 0.78 (0.65-1.21) L/min to 0.65 (0.50-0.89) L/min (P < 0.05), respectively. Propofol concentration was significantly increased from 2.21 (1.46-2.63) microg/mL to 2.45(1.79-2.89) microg/mL (P < 0.05). These data indicate that propofol concentrations can be increased by PEEP, suggesting the possibility of overdosing following PEEP.
Related Concept Videos
Parenteral Anesthetics: Overview
Stages of General Anesthesia
Inhalational Anesthetics: Overview
General Anesthesia: Overview
General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain...
Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
Mechanical Ventilation II: Invasive Ventilation
Negative-Pressure Ventilators
Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an...