Fig. 4. Sevoflurane anesthesia in infancy: Minimum alveolar concentration (MAC) survival and arterial blood gas analyses. Inspired MAC of sevoflurane, as determined by tail clamping, of postnatal day 7 rats (n = 30) during two separate 4-h anesthetic exposures (A ). Survival of postnatal day 7 rats over 4 h of sevoflurane at 1 MAC during three separate anesthetic exposures (B ). Sevoflurane-depressed respiration and caused hypercarbia (C ) but not hypoxemia (D ).