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Anaesthesia, Critical Care & Pain... Oct 2022Inhaled sedation with halogenated agents, such as isoflurane or sevoflurane, is now feasible in intensive care unit (ICU) patients through dedicated vaporisers and... (Review)
Review
Inhaled sedation with halogenated agents, such as isoflurane or sevoflurane, is now feasible in intensive care unit (ICU) patients through dedicated vaporisers and scavenging systems. Such a sedation strategy requires specific equipment and adequate training of ICU teams. Isoflurane and sevoflurane have ideal pharmacological properties that allow efficient, well-tolerated, and titratable light-to-deep sedation. In addition to their function as sedative agents, these molecules may have clinical benefits that could be especially relevant to ICU patients. Our goal was to summarise the pharmacological basis and practical aspects of inhaled ICU sedation, review the available evidence supporting inhaled sedation as a viable alternative to intravenous sedation, and discuss the remaining areas of uncertainty and future perspectives of development.
Topics: Anesthetics, Inhalation; Critical Care; Humans; Hypnotics and Sedatives; Intensive Care Units; Isoflurane; Sevoflurane
PubMed: 35907598
DOI: 10.1016/j.accpm.2022.101133 -
Current research progress of isoflurane in cerebral ischemia/reperfusion injury: a narrative review.Medical Gas Research 2022Cerebral ischemia/reperfusion injury is an important factor leading to poor prognosis in ischemic stroke patients. Therefore, it is particularly important to find... (Review)
Review
Cerebral ischemia/reperfusion injury is an important factor leading to poor prognosis in ischemic stroke patients. Therefore, it is particularly important to find effective remedial measures to promote the health of patients to return to society. Isoflurane is a safe and reliable anesthetic gas with a long history of clinical application. In recent years, its protection function to human body has been widely recognized, and nowadays isoflurane for cerebral protection has been widely studied, and the stable effect of isoflurane has satisfied many researchers. Basic studies have shown that isoflurane's protection of brain tissue after ischemia/reperfusion involves a variety of signaling pathways and effector molecules. Even though many signaling pathways have been described, more and more studies focus on exploring their mechanisms of action, in order to provide strong evidence for clinical application. This could prompt the introduction of isoflurane therapy to clinical patients as soon as possible. In this paper, several confirmed signaling pathways will be reviewed to find possible strategies for clinical treatment.
Topics: Anesthetics, Inhalation; Brain Ischemia; Humans; Isoflurane; Reperfusion Injury; Signal Transduction
PubMed: 34854416
DOI: 10.4103/2045-9912.330689 -
Journal of Acupuncture and Meridian... Jun 2018The present study aimed to determine whether isoflurane interferes with the analgesic effects of acupuncture (Ac) and electroacupuncture (EA), using a neuropathic pain...
The present study aimed to determine whether isoflurane interferes with the analgesic effects of acupuncture (Ac) and electroacupuncture (EA), using a neuropathic pain (NP) rat model. In total, 140 male Wistar rats were used; isoflurane-induced nociceptive response was evaluated using the von Frey test, serum calcium-binding protein β (S100β) levels and nerve growth factor (NGF) levels in the left sciatic nerve. The NP model was induced by chronic constriction injury of the sciatic nerve at 14 days after surgery. Treatment was initiated after NP induction with or without isoflurane anesthesia (20 min/day/8 days). The von Frey test was performed at baseline, 14 days postoperatively, and immediately, 24 h, and 48 h after the last treatment. Results of the nociceptive test and three-way analysis of variance were analyzed by generalized estimating equations, the Bonferroni test, followed by Student-Newman-Keuls or Fisher's least significant difference tests for comparing biochemical parameters (significance defined as p ≤ 0.05). At baseline, no difference was noted in the nociceptive response threshold among all groups. Fourteen days after surgery, compared with other groups, NP groups showed a decreased pain threshold, confirming establishment of NP. Ac and EA enhanced the mechanical pain threshold immediately after the last session in the NP groups, without anesthesia. Isoflurane administration caused increased nociceptive threshold in all groups, and this effect persisted for 48 h after the last treatment. There was an interaction between the independent variables: pain, treatments, and anesthesia in serum S100β levels and NGF levels in the left sciatic nerve. Isoflurane enhanced the analgesic effects of Ac and EA and altered serum S100β and left sciatic nerve NGF levels in rats with NP.
Topics: Acupuncture Analgesia; Analgesics; Animals; Disease Models, Animal; Electroacupuncture; Isoflurane; Male; Neuralgia; Rats; Rats, Wistar; Sciatic Nerve
PubMed: 29436370
DOI: 10.1016/j.jams.2018.01.004 -
Medical Gas Research 2019Central nervous system injuries are a leading cause of death and disability worldwide. Although the exact pathophysiological mechanisms of various brain injuries vary,... (Review)
Review
Central nervous system injuries are a leading cause of death and disability worldwide. Although the exact pathophysiological mechanisms of various brain injuries vary, central nervous system injuries often result in an inflammatory response, and subsequently lead to brain damage. This suggests that neuroprotection may be necessany in the treatment of multiple disease models. The use of medical gases as neuroprotective agents has gained great attention in the medical field. Medical gases include common gases, such as oxygen, hydrogen and carbon dioxide; hydrogen sulphide and nitric oxide that have been considered toxic; volatile anesthetic gases, such as isoflurane and sevoflurane; and inert gases like helium, argon, and xenon. The neuroprotection from these medical gases has been investigated in experimental animal models of various types of brain injuries, such as traumatic brain injury, stroke, subarachnoid hemorrhage, cerebral ischemic/reperfusion injury, and neurodegenerative diseases. Nevertheless, the transition into the clinical practice is still lagging. This delay could be attributed to the contradictory paradigms and the conflicting results that have been obtained from experimental models, as well as the presence of inconsistent reports regarding their safety. In this review, we summarize the potential mechanisms underlying the neuroprotective effects of medical gases and discuss possible candidates that could improve the outcomes of brain injury.
Topics: Animals; Brain Injuries; Gases; Helium; Humans; Hydrogen; Hyperbaric Oxygenation; Isoflurane; Neuroprotective Agents
PubMed: 31249256
DOI: 10.4103/2045-9912.260649 -
The Veterinary Clinics of North... Mar 1992Isoflurane offers many advantages over other inhalational anesthetics. Its faster induction and recovery, relative sparing effect on cardiovascular function and cerebral... (Review)
Review
Isoflurane offers many advantages over other inhalational anesthetics. Its faster induction and recovery, relative sparing effect on cardiovascular function and cerebral blood flow autoregulation, and negligible metabolism make this drug particularly useful in the anesthetic management of the debilitated, aged, or unusual veterinary patient.
Topics: Anesthesia, Inhalation; Animals; Birds; Cats; Costs and Cost Analysis; Dogs; Humans; Isoflurane
PubMed: 1585568
DOI: 10.1016/s0195-5616(92)50626-x -
Journal of Neuroscience Methods Jan 2022Anesthetized animal models are used extensively during neurophysiological and behavioral studies despite systemic effects from anesthesia that undermine both accurate...
BACKGROUND
Anesthetized animal models are used extensively during neurophysiological and behavioral studies despite systemic effects from anesthesia that undermine both accurate interpretation and translation to awake human physiology. The majority of work examining the impact of anesthesia on cerebral blood flow (CBF) has been restricted to before and after measurements with limited spatial resolution.
NEW METHOD
We used multi-exposure speckle imaging (MESI), an advanced form of laser speckle contrast imaging (LSCI), to characterize the dynamics of isoflurane anesthesia induction on cerebral vasculature and blood flow in the mouse brain.
RESULTS
The large anatomical changes caused by isoflurane are depicted with wide-field imagery and video highlighting the induction of general anesthesia. Within minutes of exposure, both vessel diameter and blood flow increased drastically compared to the awake state and remained elevated for the duration of imaging. An examination of the dynamics of anesthesia induction reveals that blood flow increased faster in arteries than in veins or parenchyma regions.
COMPARISON WITH EXISTING METHODS
MESI offers robust hemodynamic measurements across large fields-of-view and high temporal resolutions sufficient for continuous visualization of cerebrovascular events featuring major changes in blood flow.
CONCLUSION
The large alterations caused by isoflurane anesthesia to the cortical vasculature and CBF are readily characterized using MESI. These changes are unrepresentative of normal physiology and provide further evidence that neuroscience experiments would benefit from transitioning to un-anesthetized awake animal models.
Topics: Animals; Cerebrovascular Circulation; Hemodynamics; Isoflurane; Mice; Vasodilation; Wakefulness
PubMed: 34863840
DOI: 10.1016/j.jneumeth.2021.109434 -
British Journal of Anaesthesia Dec 1981
Comparative Study
Topics: Abnormalities, Drug-Induced; Animals; Brain; Cardiovascular System; Halothane; Hemodynamics; Humans; Isoflurane; Methyl Ethers; Mice; Neoplasms
PubMed: 7317242
DOI: 10.1093/bja/53.12.1243 -
Anesthesiology Mar 2008Thirty-six halogenated Me Et ethers have been synthesized for evaluation as volatile anesthetics. Eleven of the ethers were too unstable to test, and, of the remaining... (Review)
Review
Thirty-six halogenated Me Et ethers have been synthesized for evaluation as volatile anesthetics. Eleven of the ethers were too unstable to test, and, of the remaining 25, 13 had promising anesthetic properties in mice and are suitable for study in larger animals. Those ethers having one H with at least 2 halogens other than F or 2 or more H with at least one Br or Cl were the best anesthetics.
Topics: Animals; Chemistry, Pharmaceutical; Desflurane; Drug Design; Enflurane; Humans; Hydrocarbons, Fluorinated; Isoflurane; Methyl Ethers; Sevoflurane
PubMed: 18292690
DOI: 10.1097/ALN.0b013e31816499cc -
Anaesthesia Feb 2014
Topics: Anesthesia, Inhalation; Anesthetics, Inhalation; Desflurane; Equipment Contamination; Equipment Failure; Humans; Isoflurane; Nebulizers and Vaporizers
PubMed: 24443867
DOI: 10.1111/anae.12566 -
Anesthesiology Nov 2017Increasing numbers of patients with obstructive lung diseases need anesthesia for surgery. These conditions are associated with pulmonary ventilation/perfusion (VA/Q)...
BACKGROUND
Increasing numbers of patients with obstructive lung diseases need anesthesia for surgery. These conditions are associated with pulmonary ventilation/perfusion (VA/Q) mismatch affecting kinetics of volatile anesthetics. Pure shunt might delay uptake of less soluble anesthetic agents but other forms of VA/Q scatter have not yet been examined. Volatile anesthetics with higher blood solubility would be less affected by VA/Q mismatch. We therefore compared uptake and elimination of higher soluble isoflurane and less soluble desflurane in a piglet model.
METHODS
Juvenile piglets (26.7 ± 1.5 kg) received either isoflurane (n = 7) or desflurane (n = 7). Arterial and mixed venous blood samples were obtained during wash-in and wash-out of volatile anesthetics before and during bronchoconstriction by methacholine inhalation (100 μg/ml). Total uptake and elimination were calculated based on partial pressure measurements by micropore membrane inlet mass spectrometry and literature-derived partition coefficients and assumed end-expired to arterial gradients to be negligible. VA/Q distribution was assessed by the multiple inert gas elimination technique.
RESULTS
Before methacholine inhalation, isoflurane arterial partial pressures reached 90% of final plateau within 16 min and decreased to 10% after 28 min. By methacholine nebulization, arterial uptake and elimination delayed to 35 and 44 min. Desflurane needed 4 min during wash-in and 6 min during wash-out, but with bronchoconstriction 90% of both uptake and elimination was reached within 15 min.
CONCLUSIONS
Inhaled methacholine induced bronchoconstriction and inhomogeneous VA/Q distribution. Solubility of inhalational anesthetics significantly influenced pharmacokinetics: higher soluble isoflurane is less affected than fairly insoluble desflurane, indicating different uptake and elimination during bronchoconstriction.
Topics: Anesthetics, Inhalation; Animals; Animals, Newborn; Bronchoconstriction; Desflurane; Isoflurane; Pulmonary Ventilation; Respiration, Artificial; Swine; Ventilation-Perfusion Ratio
PubMed: 28857808
DOI: 10.1097/ALN.0000000000001847