Evaluation of a needle pH electrode for continuous tissue-pH monitoring during labor. Characteristics during acidosis in the rat.
A prototype of a needle tissue-pH (t-pH) electrode designed for continuous t-pH monitoring of the human fetus during labor is described and evaluated in vitro and in vivo in the rat. Respiratory acidosis was induced by ventilation with 5% carbon dioxide, and t-pH measured by the needle electrode compared to simultaneous t-pH measured by the Kontron-Roche electrode and to arterial blood pH. A close correlation between the two t-pH electrodes was demonstrated (r = 0.80, P < 0.001). Furthermore, a close correlation was found between t-pH and arterial blood pH during the first 15 min of acidosis (r = 0.82, P< 0.001). It is concluded that the needle electrode fulfils nearly all theoretical demands to a t-pH electrode for clinical use.
Nickelsen
C
C
Department of Obstetrics and Gynaecology, Rigshospitalet, Copenhagen, Denmark.
Weber
T
T
Hansen
A J
AJ
Hansen
A
A
Zeuthen
T
T
D000142:Acidosis, Respiratory / Q000503:physiopathology*; D000818:Animals; D004566:Electrodes; D004867:Equipment Design; D005260:Female; D005323:Fetal Monitoring / Q000295:instrumentation*; D006863:Hydrogen-Ion Concentration; D007744:Obstetric Labor Complications; D011247:Pregnancy; D051381:Rats