title: A comparison of serum ionized calcium in arterial and mixed venous blood during CPR.
abstract: Changes in the actual ionized calcium level (aCa2+) of serum in arterial and mixed venous blood during CPR were investigated in 22 patients with intrinsic cardiopulmonary arrest. Measurements were carried out at an average of 5.4 +/- 0.6 minutes (group 1) and 30 minutes (group 2) after the beginning of CPR, using simultaneously taken blood samples. The aCa2+ of groups 1 and 2 revealed no difference between arterial and mixed venous bloods. As CPR proceeded, the aCa2+ of both bloods diminished, and group 2 had a significantly lower value than did group 1 (arterial blood: 2.36 +/- 0.04 mEq/L vs 2.09 +/- 0.09 mEq/L, P less than .01; mixed venous blood: 2.37 +/- 0.05 mEq/L vs 2.13 +/- 0.06 mEq/L, P less than .001). Conversely, pH values were significantly higher for arterial blood rather than for mixed venous blood, but there was no significant change in pH between groups 1 and 2 (arterial blood, 7.11 +/- 0.05 vs 7.14 +/- 0.04; mixed venous blood, 6.93 +/- 0.04 vs 6.98 +/- 0.03). Furthermore, an analysis of the aCa2+ serum level measurements was carried out in relation to survivors and nonsurvivors and to the presence or absence of a witness at the time of the cardiac arrest. In all groups, there was no difference in aCa2+ between arterial and mixed venous blood. As CPR proceeded, however, the aCa2+ showed a significant decrease in all groups. This decrease was accompanied by a pH increase in arterial blood of patients with a witnessed cardiac arrest and in mixed venous and arterial blood of survivors.
authors.affiliation: Department of Emergency and Critical Care, Sapporo City General Hospital, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Gando
authors.forename: I
authors.initials: I
authors.lastname: Tedo
authors.forename: M
authors.initials: M
authors.lastname: Kubota
mesh_terms: D000368:Aged; D001158:Arteries; D002118:Calcium / Q000097:blood*; D004630:Emergencies; D005260:Female; D006323:Heart Arrest / Q000097:blood* / Q000401:mortality; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D012151:Resuscitation; D014680:Veins
chemical_list: D002118:Calcium