Author Block:

Giuseppe Ristagno, The Institute of Critical Care Medicine, Rancho Mirage, CA; Shijie Sun, The Institute of Critical Care Medicine, Rancho Mirage / Keck School of Medicine USC, Los Angeles, CA; Lei Huang, Yun-Te Chang, Ronald Grey, The Institute of Critical Care Medicine, Rancho Mirage, CA; Wanchun Tang, Max H Weil, The Institute of Critical Care Medicine, Rancho Mirage / Keck School of Medicine USC, Los Angeles, CA

Disclosure Block:

 G. Ristagno, None; S. Sun, None; L. Huang, None; Y. Chang, None; R. Grey, None; W. Tang, None; M.H. Weil, None.

Abstract Body:

Introduction. Previous studies demonstrated that coincident with gasping during cardiac arrest there is a prominent increase in stroke volumes in the absence of chest compression. In the present study, we investigated whether such increases are reflected in increases in cerebral microcirculatory blood flow. Methods. In an established model in Sprague-Dawley rats, end-tidal carbon dioxide tension (EtCO2) was continuously recordered, with the aid of an endotracheal tube and a capnometer (End-Tid IL 200; Instrumentation Laboratory, Lexington, MA). We performed a left craniectomy and created a window over the parieto-temporal surface of the cortex to allow for Orthogonal Polarization Spectral imaging CYTOSCAN A/R (Cytometrics Inc., Philadelphia, PA) such as to record cerebral blood flow through the surface cerebral vessels. Velocity of blood flow was graded from 0 i.e. “no flow” to 3 “normal” velocity on pial and penetrating vessels < 20 μm. Sudden increases in EtCO2 signaled the onset of and the magnitude of each gasp as previous described by our group. Results. Coincident with each gasp, both cerebral microcirculatory blood flow velocity and duration of flow were highly correleted with the corresponding increases in EtCO2 (Figure). Conclusion. Gasping produced prominent increases in cerebral microcirculatory blood flow velocity and duration of flow in close relationship to the magnitude of the gasp. Spontaneous gasping therefore produces not only ventilation and cardiac output but also striking increases in cerebral microcirculatory blood flow. Click here for Graphic