Background: We aimed to measure propofol concentrations in exhaled air with an ion mobility spectrometer coupled to a multicapillary column for pre-separation (MCC-IMS). In addition, we aimed to compare the values of these measurements with serum propofol concentrations, as determined by gas chromatography-mass spectrometry (GC-MS).
Methods: Thirteen patients, ASA I or II, undergoing elective ENT surgery were studied. Anaesthesia was induced with propofol 2.1 (0.7) mg kg(-1), rocuronium 0.5 (0.1) mg kg(-1), and remifentanil 0.5 microg kg(-1) min(-1). After tracheal intubation, anaesthesia was maintained with a continuous infusion of propofol 3.9 (1.8) mg kg(-1) h(-1) and remifentanil 0.5 microg kg(-1) min(-1). Simultaneously, a venous blood sample was obtained. Propofol concentrations in serum were determined by GC-MS and compared with the height of the respective propofol signals achieved by MCC-IMS.
Results: Twenty-four pairs of samples were obtained. The comparison of propofol concentrations in exhaled air and serum presented a bias of -10.5% and a precision of +/- 12.3%. With these values, the 95% limits of agreement were 14.1% and -35.1%.
Conclusions: MCC-IMS may be a suitable method to determine propofol concentrations in exhaled air, and may be used to predict propofol concentrations in serum.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/bja/aep312 | DOI Listing |
Front Pharmacol
January 2025
Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, Guangdong Province, China.
Purpose: The incidence of hemodynamic instability associated with dexmedetomidine (DEX) sedation has been reported to exceed 50%, with substantial inter-individual variability in response. Genetic factors have been suggested to contribute significantly to such variation. The aim of this study was to identify the clinical, pharmacokinetic, and genetic factors associated with DEX-induced hemodynamic instability in pediatric anesthesia patients.
View Article and Find Full Text PDFBJA Open
March 2025
Department of Anaesthetics, Royal Prince Alfred Hospital, Sydney, NSW, Australia.
Background: Intraoperative awareness, without explicit recall, occurs after induction of anaesthesia in approximately 10% of persons under 40 yr of age. Most anaesthetic agents minimally suppress the noradrenergic system. We hypothesised that addition of dexmedetomidine, which suppresses noradrenergic activity, may reduce encephalographic (EEG) arousal in response to tracheal intubation; such an effect would lay the foundation for future studies of dexmedetomidine in reducing intraoperative awareness.
View Article and Find Full Text PDFPain
December 2024
Department of Cell and Developmental Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
The mesopontine tegmental anesthesia area (MPTA) is a focal brainstem locus which, when exposed to GABAergic agents, induces brain-state transitioning from wakefulness to unconsciousness. Correspondingly, MPTA lesions render animals relatively insensitive to GABAergic anesthetics delivered systemically. Using chemogenetics, we recently identified a neuronal subpopulation within the MPTA whose excitation induces this same pro-anesthetic effect.
View Article and Find Full Text PDFBMC Vet Res
January 2025
Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China.
Background: Mixed exhaled air has been widely used to determine exhaled propofol concentrations with online analyzers, but changes in dead space proportions may lead to inaccurate assessments of critical drug concentration data. This study proposes a method to correct propofol concentration in mixed air by estimating pulmonary dead space through reconstructing volumetric capnography (Vcap) from time-CO and time-volume curves, validated with vacuum ultraviolet time-of-flight mass spectrometry (VUV-TOF MS).
Methods: Existing monitoring parameters, including time-volume and time-CO curves, were used to determine Vcap.
Pharmaceutics
December 2024
Department of Pharmaceutical Sciences, School of Pharmacy and Nutrition, University of Navarra, 31008 Pamplona, Spain.
: Despite the known impact of propofol and remifentanil on hemodynamics and patient outcomes, there is a lack of comprehensive quantitative analysis, particularly in surgical settings, considering the influence of noxious stimuli. The aim of this study was to develop a quantitative semi-mechanistic population model that characterized the time course changes in mean arterial pressure (MAP) and heart rate (HR) due to the effects of propofol, remifentanil, and different types of noxious stimulation related to the clinical routine. : Data from a prospective study were used; the study analyzed the effects of propofol and remifentanil general anesthesia on female patients in physical status of I-II according to the American Society of Anesthesiologists (ASA I-II) undergoing gynecology surgery.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!