The ability of the Hon Cardiodynamic monitoring system to detect changes in the peripheral microcirculation in true versus false labor

Abstract

To evaluate the ability of the Hon Cardiodynamic Monitoring System (Hon CDMS) to differentiate true versus false labor through assessment of hemodynamic changes in the peripheral microcirculation. Twenty-two contracting pregnant women including 11 term contracting (TC) and 11 preterm contracting (PTC) were tested with the Hon CDMS. Contracting women were admitted with at least 6 contractions per hour, and were at least 1 cm dilated and 50% effaced. Contracting women who delivered or demonstrated cervical change within 24 hours of testing were considered to be in “true labor”. The remainder were considered to be in “false labor”. Hemodynamic parameters of heart rate (HR), pulse wave arrival time (PWAT), rapid ejection time (RET), and cutaneous pulse pressure (cPP) were evaluated on admission using the Hon CDMS. Findings were compared for true and false labor groups. P < .05 was considered significant. Twelve women were classified “true labor” (10 TC and 2 PTC) and 10 “false labor” (1 TC and 9 PTC). Using the Hon CDMS, cycling (changes in the hemodyamic parameters with contractions) were detected in all 12 true labor patients. Eight of the 10 false labor patients showed no cycling (1 TC and 9 PTC) and 2 had only sporadic cycling during the first 6 minutes of 36 minute testing. The predictive values of the Hon CDMS were: Sensitivity 100%, Specificity 80%, PPV 86%, and NPV 100%. The Hon CDMS by identifying cycling as concomitant cardiovascular changes with contractions may have the potential of providing useful data for providers to determine whether contracting gravidas are in true or false labor.