Background: The principal site for elimination of propofol is the liver. The clearance of propofol exceeds hepatic blood flow; therefore, extrahepatic clearance is thought to contribute to its elimination. This study examined the pulmonary kinetics of propofol using part of an indocyanine green (ICG) recirculatory model.
Methods: Ten sheep, immobilized in a hammock, received injections of propofol (4 mg/kg) and ICG (25 mg) via two semipermanent catheters in the right internal jugular vein. Arterial blood samples were obtained from the carotid artery. The ICG injection was given for measurement of intravascular recirculatory parameters and determination of differences in propofol and ICG concentration-time profiles. No other medication was given during the experiment, and the sheep were not intubated. The arterial concentration-time curves of ICG were analyzed with a recirculatory model. The pulmonary uptake and elimination of propofol was analyzed with the central part of that model extended with a pulmonary tissue compartment allowing elimination from that compartment.
Results: During the experiment, cardiac output was 3.90+/-0.72 l/min (mean +/- SD). The blood volume in heart and lungs, measured with ICG, was 0.66+/-0.07 l. A pulmonary tissue compartment of 0.47+/-0.16 l was found for propofol. The pulmonary first-pass elimination of propofol was 1.14+/-0.23 l/min. Thirty percent of the dose was eliminated during the first pass through the lungs.
Conclusions: Recirculatory modeling of ICG allows modeling of the first-pass pulmonary kinetics of propofol concurrently. Propofol undergoes extensive uptake and first-pass elimination in the lungs.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1097/00000542-199912000-00032 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A New Neuroanesthetic Protocol of Rendering Specialized Care in Treating Degenerative Lumbar Spine Diseases in High-Risk Patients: Prospective Analysis of the Results.
Sovrem Tekhnologii Med
December 2024
MD, DSc, Professor, Head of the Department of Neurosurgery and Innovative Medicine; Irkutsk State Medical University, 1 Krasnogo Vosstaniya St., Irkutsk, 664003, Russia; Chief of the Center of Neurosurgery; Russian Railways-Medicine Clinical Hospital, 10 Botkin St., Irkutsk, 664005, Russia; Professor, Department of Traumatology, Orthopedics and Neurosurgery; Irkutsk State Medical Academy of Postgraduate Education, 100 Yubileyny Microdistrict, Irkutsk, 664049, Russia.
Unlabelled: is to assess the effectiveness of a new neuroanesthetic protocol for treating degenerative lumbar spine diseases in high-risk patients.
Materials And Methods: Two groups of patients with a high risk of anesthesia and surgery determined by the authors' clinical decision support system (CDSS) have been prospectively studied. A new neuroanesthetic protocol was used in the experimental group (EG, n=25), while the control group (CG, n=25) underwent intravenous anesthesia based on propofol and fentanyl.
Cardiorespiratory effects of gamma-hydroxybutyric acid during isoflurane anaesthesia in pigs.
Vet Anaesth Analg
October 2024
Department of Large Animal Surgery, Anaesthesia and Orthopaedics, Ghent University, Merelbeke, Belgium.
Objective: To investigate the haemodynamic effects of gamma-hydroxybutyric acid (GHB) in isoflurane-anaesthetized pigs.
Study Design: Experimental, randomized, nonblinded, crossover study.
Animals: A group of six stress-resistant Landrace pigs (approximately 3 months old; three male, three female; bodyweight 39.
Population Pharmacokinetic Modelling of Norepinephrine in Healthy Volunteers Prior to and During General Anesthesia.
Clin Pharmacokinet
November 2024
Department of Anaesthesiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.
Article Synopsis
- Intraoperation hypotension (IOH) during surgery can have negative effects, leading to the routine use of norepinephrine (NE) to manage blood pressure under general anesthesia, although its pharmacokinetics during such conditions are not well understood.
- The study aimed to analyze the pharmacokinetics of NE in healthy volunteers in both awake and general anesthesia states, using a step-up dosing method and measuring plasma concentrations.
- Results indicated that a two-compartment model effectively described NE dynamics, finding that general anesthesia reduced NE clearance by 10%, with weight, age, and session (awake vs. anesthesia) being significant factors affecting its clearance.
Propofol-mediated loss of consciousness disrupts predictive routing and local field phase modulation of neural activity.
Proc Natl Acad Sci U S A
October 2024
Department of Psychology, Vanderbilt University, Nashville, TN 37235.
Article Synopsis
- Predictive coding helps the brain make guesses about what we will hear or sense next, which involves different brain waves working together.
- When monkeys were put to sleep with a drug, their brains stopped using these guessing signals, which changed how they reacted to unexpected sounds.
- This study shows that being aware of things (consciousness) is linked to how well the brain predicts and processes information, and when we’re unconscious, those predictions don’t work like they should.
Is the combination of interfascial plane blocks sufficient for awake breast cancer surgery? An observational, prospective, proof-of-concept study.
BMC Anesthesiol
September 2024
Department of Anesthesiology and Reanimation, Samsun University Faculty of Medicine, Samsun Training and Research Hospital, Barış Bulvarı Kadıköy Mahallesi No : 199 PK : 55090 İlkadım, Samsun, Turkey.
Article Synopsis
- Breast cancer surgery often requires anesthesia, with awake surgery gaining traction due to risks associated with general anesthesia and patient preference.
- A study from July 2022 to July 2023 tested ultrasound-guided fascial plane blocks for anesthesia in awake breast surgeries, enrolling 17 patients who met specific criteria.
- Results showed that 15 out of 17 patients achieved effective anesthesia, with high satisfaction rates and no complications, suggesting this method could reduce the need for general anesthesia in breast cancer surgeries.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!