Anesthesia and analgesia
-
Anesthesia and analgesia · May 2010
Isoflurane anesthesia does not satisfy the homeostatic need for rapid eye movement sleep.
Sleep and general anesthesia are distinct states of consciousness that share many traits. Prior studies suggest that propofol anesthesia facilitates recovery from rapid eye movement (REM) and non-REM (NREM) sleep deprivation, but the effects of inhaled anesthetics have not yet been studied. We tested the hypothesis that isoflurane anesthesia would also facilitate recovery from REM sleep deprivation. ⋯ Unlike propofol, isoflurane does not satisfy the homeostatic need for REM sleep. Furthermore, the regulation and organization of hippocampal events during anesthesia are unlike sleep. We conclude that different anesthetics have distinct interfaces with sleep.
-
Anesthesia and analgesia · May 2010
The link between intravenous multiple pump flow errors and infusion system mechanical compliance.
IV drug delivery in intensive care often takes the form of simultaneous multiple infusions from separate infusion devices via either shared or individual fluid pathways. Because of the potency of the drugs administered and the acuity of the patients, accurate drug delivery is required. ⋯ We describe a mathematical model of a simple infusion system used to investigate and verify results reported from a simple experimental multiple pump fault scenario. The results suggest that flow degradation is attributable to small changes in infusion system extracorporeal volume, referred to as "compliance." The model may, by expansion, be used to determine the nature of fluid flow within other multiple pump systems, be applied to the design of future IV systems, and explain the need for small-volume infusion systems with small mechanical compliance.
-
Anesthesia and analgesia · May 2010
The effects of isoflurane pretreatment on cerebral blood flow, capillary permeability, and oxygen consumption in focal cerebral ischemia in rats.
We performed experiments to test whether isoflurane pretreatment produces vascular effects, especially at the levels of arterioles and capillaries affecting regional cerebral blood flow (rCBF), O(2) supply and consumption, or capillary permeability in focal cerebral ischemia. Because inducible nitric oxide synthase (iNOS) was implicated as one of the mechanisms of isoflurane preconditioning, the effect of iNOS inhibition on rCBF was also studied. ⋯ Our data demonstrate that isoflurane pretreatment improved rCBF and increased the regional O(2) supply and consumption in the focal ischemic area but did not affect capillary permeability during the early stage of focal cerebral ischemia. The isoflurane-induced increase in rCBF in the ischemic area became insignificant with inhibition of iNOS.