From: Isoflurane Differentially Affects Neurogenesis and Long-term Neurocognitive Function in 60-day-old and 7-day-old Rats Anesthes. 2009;110(4):834-848. doi:10.1097/ALN.0b013e31819c463d Figure Legend: Fig. 1. Minimum alveolar concentration (MAC), physiologic variables, and survival during 4-h isoflurane in rats. MAC was determined using the response to tail clamping of ten or more simultaneously anesthetized rats. A second order polynomial fit was applied to the MAC data of postnatal day (P)7 rats (  A  ). Blood withdrawn blindly from the left cardiac ventricle under general (  isoflurane groups  ) or local anesthesia (  control  ) was analyzed in a blood gas analyzer and oxygen tension (  B  ), glucose concentration (  C  ), carbon dioxide tension (  D  ), and pH (  E  ) were determined. Only one sample was obtained per P7 rat, whereas four blood samples were drawn from every P60 cardiorespiratory control rat (n = 6). Data are medians and interquartile ranges except glucose concentrations (median, range) and survival (  F  ); mean, 95% confidence interval). Only those rats that awoke from anesthesia were considered survivors. Two rats in the P7 isoflurane group survived 4 h of isoflurane but died before awakening from anesthesia. None of the unanesthetized control animals died (not shown). FiO2= fraction of inspired oxygen; PCO2= partial pressure of carbon dioxide; PO2= partial pressure of oxygen.  Date of download: 12/21/2017 Copyright © 2017 American Society of Anesthesiologists. All rights reserved.