Evaluation of Fever Occurring in Labor in Patients Receiving Epidural Anesthesia
Evaluation of Fever Occurring in Labor in Patients Receiving Epidural Anesthesia
Briefly, the investigators propose to evaluate nulliparous (first time mothers) patients
 beyond 36 0/7 weeks' gestation in active labor who already have received epidural anesthesia
 and have an intrauterine pressure catheter (IUPC) in place. Any patient who then develops a
 single temperature elevation of > 38 degrees will be eligible for inclusion and consented for
 the study. Maternal blood will be drawn immediately, one hour later and at delivery. Amniotic
 fluid will be aspirated from the pressure catheter; the first 1-2 cc will be discarded and
 the remainder will be evaluated for gram stain, culture, glucose level, interleukin-6 (IL-6),
 and proteomics. All placentas will be sent for routine pathologic examination. Cord blood
 will be obtained at birth for routine studies. Both maternal and cord blood will be sent for
 proteomic evaluation (defined). The patients with amniotic fluid that has a positive gram
 stain and culture will be defined as the infected group, and the patients with amniotic fluid
 that has a negative gram stain and culture will be defined as the uninfected group.
 Differences in clinical presentation and laboratory assessments, including proteomics, will
 be compared between the two groups to determine if there are any markers that might prove to
 be useful in distinguishing between these two entities (epidural fever with and without
 actual infection).
Historically the diagnosis of chorioamnionitis (an infection of the membranes surrounding the
 fetus) for patients in labor has been made on the basis of multiple clinical variables such
 as maternal fever, fetal tachycardia, uterine tenderness, or foul smelling vaginal discharge.
 The diagnosis also takes into account a clinical picture consistent with risk factors such as
 prolonged labor and prolonged rupture of membranes. Since most of these findings are not
 specific, chorioamnionitis becomes the diagnosis of exclusion unless there is another
 explanation for the fever. Randomized studies have clearly shown that maternal antibiotics
 and neonatal septic work-ups are indicated once the diagnosis of chorioamnionitis has been
 made. Neonatal sepsis is a severe infection of the blood stream. Such policies have important
 implications for health care providers, on the impact of medical costs, and on the duration
 of hospital stay. This becomes especially true for the newborn that is transferred to the
 neonatal intensive care unit (NICU) for sepsis evaluation. Often times, these newborns are
 prophylactically treated with antibiotics based on the suspicion of an infection, while
 waiting for finalized blood culture results. Since newborn sepsis is such a difficult
 diagnosis to make, many more newborns are treated than actually have the disease and the
 length of their hospital stay may be significantly increased.

 Over the past 15 years, both observational and randomized trials have observed an increase in
 maternal fever associated with epidural anesthesia in labor. These trials have shown
 increased ranges from 10 - 15% over baseline rates and an increased relative risk of 1.5 to
 15 fold, and even up to 70 fold in one study, over the rates seen in women not receiving
 epidural anesthesia. After correcting for duration of labor and other confounding variables,
 these increases remained present. Since epidural fever is virtually impossible to distinguish
 from chorioamnionitis-related fever, these women are almost all treated with antibiotics and
 given the diagnosis of infection. This approach also has tremendous impact on the evaluation
 and care of the newborn. Two specific studies evaluated this impact on the neonate. Lieberman
 found that babies of mothers given epidural anesthesia were more likely to be evaluated for
 sepsis (34 vs. 9%) and treated with antibiotics (15 vs. 4%). Similarly, Philips found the
 same increase (25 vs. 16% and 19 vs. 11%). Both studies had very low rates of confirmed
 neonatal sepsis. On a national basis, the cost of this confusion nationally is tremendous.

 There is one known way to distinguish between true chorioamnionitis in labor and
 non-infectious fever due to the epidural anesthesia. Gibbs and colleagues found that amniotic
 fluid aspirated from an intrauterine pressure catheter, a device commonly utilized for
 monitoring contractions in labor, could be used to accurately make the diagnosis of infection
 using gram stain and culture. More recently, many papers have shown that low glucose levels
 and elevated IL-6 in amniotic fluid were also accurate tests for infection. While these
 markers could in theory be used for distinguishing between epidural fever and true
 chorioamnionitis, most patients do not require such a device and this approach would not
 likely gain widespread favor. Alternatively, however, this approach could be used as a
 research tool in women who already have such a catheter in place to determine if there are
 additional non-invasive clinical or laboratory markers to distinguish one from the other.

 Recently proteomic assessment has become an extremely effective tool in determining if there
 are certain markers for various diseases. Proteomics is the determination of the structure,
 function, and expression of all of the corresponding proteins that are encoded within the
 genome structure. It can also be defined as the "fingerprint" of a disease process. It
 involves running tandem mass spectometry on the fluid of interest. Such an approach could be
 extremely valuable both in determining whether the mother actually has chorioamnionitis and,
 if so, whether there are better markers for neonatal sepsis.
Inclusion Criteria:

 -  Nulliparous

 -  Maternal age > 18 years of age

 -  Estimated gestational age (EGA) > 36 0/7 weeks

 -  Active labor (> 4 cm dilated)

 -  Epidural anesthesia

 -  IUPC in place prior to development of fever

 -  Temperature of > 38 degrees

 -  Consents to study

 Exclusion Criteria:

 -  Multiparous

 -  Maternal age < 18 years of age

 -  External tocometer