Resuscitation
-
Comparative Study
Pentoxifylline alone versus pentoxifylline combined with superoxide dismutase prolongs survival in a rat hemorrhagic shock model.
Pentoxifylline (PTX) and superoxide dismutase (SOD) have each proven effective in improving survival when administered during resuscitation in animal models of hemorrhagic shock. This study was conducted to determine if PTX and SOD combined would have synergistic effectiveness in the treatment of hemorrhagic shock. Sprague-Dawley rats (n = 40) were phlebotomized at 25 ml/kg for 2 min, then subjected to a 45-min ischemic period, and resuscitated with lactated Ringer's solution (LR) (50 ml/kg) over 1 h. ⋯ Animals were randomized into groups to receive one of the following agents during resuscitation: PTX in LR, SOD in LR, a combination of PTX and SOD in LR, or LR alone. PTX or SOD alone were effective in prolonging survival. However, the combination of PTX and SOD did not prolong survival above LR control.
-
Return of spontaneous circulation with CPR is a function of coronary perfusion pressure, which is determined by vasomotor tone and the force of compression. Vasomotor tone is affected by the relative stimulation of arterial vasoconstricting and vasorelaxing receptors by vasoactive substances. We measured the plasma levels of the endogenous vasoactive peptides arginine vasopressin (AVP) angiotensin II (ANG-II) and atrial natriuretic peptide (ANP) during cardiac arrest and resuscitation. ⋯ There were significant increases in the levels of these endogenous vasoactive peptides. This reflects the neuroendocrine response to global ischemia and CPR reperfusion. Plasma levels of these peptides may effect the vital organ perfusion pressures, response to exogenous vasopressors, and outcome of resuscitative efforts. Future therapies may be directed at enhancing or blocking the effect of these peptides so as to optimize perfusion pressure which is one of the principle determinants of outcome during CPR.
-
Epinephrine is used to increase coronary perfusion pressure and improve myocardial blood flow during cardiac arrest. Alternative vasopressors may have hemodynamic advantages over epinephrine. The purpose of this investigation was to test the effect of the vasopressor angiotensin II on myocardial blood flow in a swine model of cardiac arrest. ⋯ This fell to 15.1 +/- 19.9 with CPR alone, and rose to 66.9 +/- 69.8 following angiotensin II administration (P = 0.04; by two tailed T-test). Myocardial blood flow following ROSC further increased to 212.6 +/- 58.0. Angiotensin II in a dose of 50 micrograms/kg significantly increases myocardial blood flow in this model of cardiac arrest.
-
Comparative Study
End-tidal CO2 and plasma lactate level: a comparison of their use as parameters for evaluating successful CPR.
Serial changes of end-tidal CO2 (ETCO2) and plasma lactate levels during CPR have been described as useful to investigate or evaluate the results of CPR. However, there have been no reports comparing these parameters in the same model. By inducing cardiopulmonary arrest (2-7 min) in 28 Wistar rats, ETCO2 and serum lactate levels were studied after and just before CPR, respectively. ⋯ The lactate levels before CPR in two groups were significantly higher than those of control levels, however there was no significant difference just before the CPR between the two groups. ETCO2 during CPR is a useful indicator for determining the successful application of CPR. However, serum lactate levels sampled just before the onset of CPR did not prove to be a useful indicator of successful CPR in rats.