RESUMO
A porcine model of cardiac arrest with irreversible electromechanical dissociation was associated with highly significant decreases in colloid osmotic pressure in the absence of increases in hematocrit during the initial half hour of CPR. Pulmonary edema was typically observed. These observations are best explained by increases in capillary permeability to plasma proteins. The progression of acidemia was remarkably slow; arterial blood pH remained normal for more than 16 min. Even though there was significant lactic acidosis, concurrent respiratory alkalosis during CPR accounted for the greatly delayed onset of acidemia. There was also an as-yet unexplained increase in plasma osmolality.
Assuntos
Parada Cardíaca/fisiopatologia , Animais , Bicarbonatos/sangue , Pressão Sanguínea , Dióxido de Carbono/sangue , Eletrólitos/sangue , Parada Cardíaca/sangue , Parada Cardíaca/terapia , Hematócrito , Concentração de Íons de Hidrogênio , Concentração Osmolar , Ressuscitação , SuínosRESUMO
Utilizing a well-established porcine model of cardiac arrest, we found that end-tidal CO2 concentration (ETCO2) strikingly decreased to approximately 24% of control levels, immediately after cardiac arrest and before precordial compression. During precordial compression, ETCO2 progressively increased to 46% of control values in successfully resuscitated animals but only to 26% in animals which failed to respond to resuscitation efforts. After successful resuscitation, ETCO2 rapidly returned to baseline values. These data indicate that ETCO2 may be a useful monitor for assessing the adequacy of CPR.