A Study to Determine the Utility of a Cardiodynamic Monitoring System to Differentiate False and True Labor in Pregnant Women Presenting with Symptoms of Preterm Labor Kevin M. Proctor, BA, Cristina Martinez, Rosiane Mattar, MD, Risa Ramsey, RN, PHD(c), MBA, CCRC, Lucinda Del Mar, MD, RA University of Tennessee Health Science Center, Department of Obstetrics and Gynecology, Memphis, TN, USA; Universidade Federal de São Paulo/ Escola Paulista de Medicina, Centro Obstetrico, São Paulo, SP, Brazil.  Yale University, Department of History of Science and Medicine,  Christian Brother’s University, Department of Biology,  Universidade Federal de São Paulo/ Escola Paulista de Medicina,  University of Tennessee, Department of Obstetrics and Gynecology, University of Tennessee, Department of Obstetrics and Gynecology
Background • Nearly 10% of pregnancies develop some form of complications. • Of these, preterm delivery is a chief concern, producing immature infants, which face potential disabilities. • Though tocodynamometry has been used as a method of diagnosis, it is only 50% effective. • “False labor” and “true labor” are exceptionally difficult to distinguish at term. • Stress and progesterone / estrogen imbalance are among the main causes of preterm labor. • The inability to differentiate between these two forms of labor can lead to unnecessary medical expenses and inaccurate/inappropriate management of labor, resulting in maternal and fetal health risks and morbidity.
Background continued • Previous studies have made a connection between hemodynamic parameters and uterine contractions • Thus, concominant observance of uterine contractions and cardiodynamic monitoring are potentially useful as a means of determining true labor from false labor. • During this study we used a monitoring system created by Dr. Edward H. Hon, a renowned researcher working out of King/ Drew Medical Center in Los Angeles, California. • This system uses a noninvasive cardiovascular recording technique, which could potential aid in monitoring vascular motility and the cardiovascular system of patients experiencing preterm labor. • Through pursuing this research project it is hoped that this investigation would lead to the development of a screening management tool that will aid in the identification of patients who are experiencing false labor from those experiencing true preterm labor.
AIMS • Through this study we are interested in highlighting the differences between the hemodynamic paremeter of Rapid Ejection Time (RET),Cutaneous pulse pressure (cPP),Heart Rate (HT) and Pulse Wave Arrival Time of patients experiencing false labor versus those experiencing true preterm labor. • In addition, how the hemodynamic parameters values change through the labor management of a patient once admitted: on admissions, one hour post hydration, one hour post tocolysis, and twenty four hours after cessation of contractions.
Instrumentation: • A cutaneous pulse pressure (cPP) transducer is applied over the phalanx of the patient’s finger • An ECG electrode is attached to the patients chest • The cPP transducer and the ECG electrode are plugged into a data processing unit, which is connected to a laptop and to a printer • Hewlett Packard Series 50 XM for monitoring tocodynamometry • The data including cPP, HR, RET and PWAT is displayed as graph
ELECTRO- ---> Electrodes ---> CARDIOGRAM Micro- Laptop ----> ---> ---> Printer Computer Computer Pressure CUT ANEOUS ---> T ransducer ---> PULSE PRESSURE Instrumentation Models
Our role in the hospital • Two six hour shifts (8am-2pm and 2pm-8pm)* • Remaining in obstetrics ward screening incoming patients. • Admitted patients were screened, the majority of which could not be included. • Those meeting all inclusion criteria were explained the study and had to sign a consent form. • Participating women were given a complimentary item of clothing for their new born. *On call, if case presented itself
Inclusion Criteria • Pregnant women between the age of 16 and 40 years old • Gestational age between 24 and 37 weeks. • Uterine Contractions of 6 per hour or less that 3 contractions in 30 minutes and at least one of the followings: a)Cervical dilation of 1cm or less and 50% thinning of the cervix b) Constant increase in cervical dilation or thinning of the cervix
Exclusion Criteria Maternal factors • Premature membrane rupture • Diagnosis of abruptio placentae, placenta previa or vaginal bleeding • Suspected chorioamnionitis • Severe preeclampsia or eclampsia • Cerclage Fetal factors • IUGR (Intrauterine growth restriction) • Fetal distress • Fetal death
Procedures The Test Consisted of: • Applying the (cPP) transducer on the finger of the patient’s left hand. • The transducer measure the blood flow and small changes in blood vessels from the skin of the fingertip. • Placing an ECG electrode to the suprasternal area (upper chest) of the patient • The electrode recorded the electrical activity of the mother’s heart • The fetal heart rate and the mother’s uterine contraction were monitored using a Hewlett Packard Series 50 XM • This procedure only takes 12 minutes
Testing Administration • Testing was to take place at: • Admissions • One hour post hydration • One hour post tocolytis • After 24 hours of cessation of contractions if not previously discharged from the hospital
Data Patients admitted before or after shift hours are not included, though patients meeting inclusion criteria and seen outside of shift hours were included.
Villa Mariana June 6, 2003 – June 30, 2003
July 1, 2003 – August 7, 2003 Dr. Pricila and Dr. Rosiane, our mentors in Brazil.
The Staff To fill the lulls in time between admitted patients, we frequently observed births and surgical procedures.
Results • This study is being continued at the University of Tennessee Health Science Center, Department of Obstetrics and Gynecology in Memphis, TN.