SUMMARY

Volatile anesthetics exert profound effects on the cardiovascular system by altering the inotropic, chronotropic, dromotropic, and lusitropic state of the heart. These agents also have significant actions on the preload and afterload systems. The pharmacologic effects cause dramatic changes in hemodynamics that may be accentuated in patients with underlying cardiovascular disease. Less profound but equally important effects are observed with nitrous oxide and xenon. Some of the volatile anesthetics have been shown to be cardioprotective, directly reducing the sequelae of ischemia and reperfusion injury. The use of inhalational anesthetics requires clear understanding of their complex cardiovascular pharmacology.

216

Figure 7-25 Histograms show the effects of isoflurane (ISO) and xenon on the preload recruitable stroke work slope (M_W , top panel), the peak rate of increase of left ventricular pressure (+dP/dt_max , middle panel), and percent segment shortening (%SS, bottom panel) in normal (red bars) and cardiomyopathic (gray bars) dogs receiving 1.5 minimum alveolar concentration (MAC) of isoflurane in the presence and absence of 30%, 50%, and 65% xenon. *, Significantly (P < .05) different from control; †, significantly (P < .05) different from ISO alone; ‡, significantly (P < .05) different from ISO and 30% xenon; ¶, significantly (P < .05) different from the corresponding value in normal dogs.