380 MMHG TO ATM SKIN
380 MMHG TO ATM MAC

MAC is analogous to the pharmacologic effective dose (ED 50) of drugs. MAC is inversely related to anesthetic potency and, therefore, with its lipid solubility (Meyer-Overton theory).

MAC has been determined in different age groups, under different conditions, and for all inhalation anesthetic agents ( Table 62-1), allowing for comparison of the potency of the different agents.

380 MMHG TO ATM SKIN

Minimum alveolar concentration (MAC) is the alveolar concentration of an inhalation anesthetic agent at 1 atm and at steady-state concentration necessary to suppress a gross purposeful movement in 50% of patients in response to a skin incision. Therefore, a method for quantifying the amount of inhalation agent necessary for anesthesia has been devised. However, for inhalation anesthetic agents, the mass of drug and patient weight have little to do with the intensity of the drug effect. Thus, you will need to dial a higher concentration at high elevation to attain the same clinical effect as at sea level with desflurane (Tec-9) vaporizer.CHAPTER 62 Minimum alveolar concentrationДosing for most drugs is based on mass of drug per kilogram of patient body weight. But when that 5% desflurane leaves the vaporizer at high altitude, what is delivered to the patient is 5% of a decreased ambient pressure, so the partial pressure of desflurane in the alveoli will be much less that it would be at sea level. of the gas,in atm, assuming no change in moles or temperature a) 2.4 atm b). So at any altitude, when you dial 5%, it will give you 5%. 13) The volume of a gas with an initial pressure of 380 mmHg atm increases.

The number on the dial reflects the percentage that will be delivered. Thus, the vaporizer slightly overcompensates for the reduced atmospheric pressureвЂ¦ Note that this does NOT apply to the desflurane vaporizerвЂњ(Source 1).ДЄlternatively, the desflurane vaporizer is electrically heated to 39 degrees centigrade, which creates a vapor pressure of 2 atmospheres inside the vaporizer, regardless of ambient pressure.

However, our vaporizer, set for 1.1%, is actually producing 1.7%, or a partial pressure of 9.9 mm Hg. You can also convert standard atmosphere to pascal, exapascal, petapascal, terapascal, gigapascal, megapascal, kilopascal, hectopascal, dekapascal, decipascal, centipascal, millipascal, micropascal, nanopascal, picopascal, femtopascal, attopascal, newton/square meter, newton/square centimeter, newton. However, according to DaltonвЂ™s law, the partial pressure of isoflurane delivered would be approximately the same at both altitudes since 2% isoflurane at 760mm Hg (15.2 mm Hg) is the same as 4% isoflurane at 380mm Hg (15.2 mm Hg).ДЄccording to Shafer, who presents an example on Stanford UniversityвЂ™s website, вЂњwe find that to deliver 8.4 mm Hg (1 MAC) of isoflurane at 8000 feet, we need an anesthetic concentration of 1.5%. 1 atm 760.02006282298 mmHg / Convert standard atmosphere to millimeter mercury (0C). Therefore, the settings that delivered 2% isoflurane now deliver 4% isoflurane. Where VO=vapor output (ml), CG= carrier gas flow(mL.min), SVP=saturated vapor pressure (mm Hg) at room temp, and Pb is barometric pressure (mm Hg)ДЄt a higher altitude where the barometric pressure is ВЅ that at sea level, the amount of isoflurane vapor output increases due to the lower barometric pressure. However, if the question relates to volume concentration then use equation: So if you are doing anesthesia with isoflurane at high altitude, setting the dial to 1% will have the same effect as it would at sea level. The partial pressure of the anesthetic agent is what determines whether a patient is anesthetized, and it does not change at different altitudes. Gas pressure is measured in units such as torr, mmHg, atm, and Pa. Even though the units on the dial are percentages, itвЂ™s actually partial pressure that is determined. A gas exerts pressure, the force of the gas particles striking the walls of its container. They automatically compensate for changes in altitude because they put out a partial pressure that is determined by the position of the dial. Modern conventional vaporizers (for halothane, isoflurane, sevoflurane) are agent specific, temperature compensated, variable bypass vaporizers. A gas sample contained in a cylinder equipped with a moveable piston occupied 300. Since most of us work at about 1 atmosphere, we can still think in terms of % concentration, but what is physiologically important is the partial pressure (mm Hg), not the concentration. The definition of MAC is the concentration of the vapor (measured as a percentage at 1 atmosphere, i.e the partial pressure) that prevents the reaction to a standard surgical stimulus in 50% of subjects.

380 mmhg to atm