title: The effect of adding a background infusion to patient-controlled epidural labor analgesia on labor, maternal, and neonatal outcomes: a systematic review and meta-analysis.
abstract: BACKGROUND
  Patient-controlled epidural analgesia (PCEA) has gained popularity, but it is still unclear whether adding a background infusion confers any benefit.
  
  
  METHODS
  A systematic literature search in PubMed, Embase, CINAHL, LILACS, CENTRAL, Clinicaltrials.gov, and ISI WOS was performed to identify randomized controlled double-blind trials that compare PCEA-only with PCEA combined with a continuous infusion (PCEA + CI) in parturients. The data were subjected to meta-analyses using the random-effects model. Our primary outcome was the incidence of instrumental vaginal delivery. Secondary outcomes were incidences of spontaneous vaginal and cesarean deliveries, duration of labor, analgesic outcomes, maternal outcomes (visual analog scale scores for pain, maternal satisfaction, nausea, pruritus, hypotension), and neonatal outcomes (Apgar score, umbilical artery pH).
  
  
  RESULTS
  We identified 7 trials with a low risk of bias, reporting on 891 parturients, for inclusion in our systematic review. The risk of instrumental vaginal delivery was increased in the PCEA + CI group, risk ratio (RR) 1.66 (95% confidence interval 1.08-2.56, P = 0.02; I = 0%); the RR for cesarean delivery was 0.83 (95% confidence interval 0.61-1.13, I = 0%). The second stage of labor was prolonged (weighted mean difference 12.3 minutes, 95% confidence interval 5.1-19.5 minutes, P = 0.0008; I = 0%) in the PCEA + CI group. Fewer patients in the PCEA + CI group required physician-administered boluses (RR 0.35 [95% confidence interval 0.25-0.47, P < 0.00001; I = 0%]). No differences regarding maternal adverse events (nausea, pruritus, hypotension) or neonatal outcomes (Apgar scores <7, umbilical artery pH) were observed.
  
  
  CONCLUSIONS
  On the basis of current evidence, no conclusion can be drawn regarding the risks or benefits of adding a continuous background infusion to PCEA compared with PCEA-only epidural labor analgesia. Further high-quality studies involving a sufficient number of patients are required.
authors.affiliation: From the Department of Anaesthesia, Kantonsspital Baden, Baden, Switzerland; Department of Anesthesiology, Klinikum am Bruderwald, Bamberg, Germany; Department of Anesthesiology, University Hospital Aachen, Aachen, Germany; and Division of Preventive Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Heesen
authors.forename: Johannes
authors.initials: J
authors.lastname: Böhmer
authors.forename: Sven
authors.initials: S
authors.lastname: Klöhr
authors.forename: Thomas
authors.initials: T
authors.lastname: Hofmann
authors.forename: Rolf
authors.initials: R
authors.lastname: Rossaint
authors.forename: Sebastian
authors.initials: S
authors.lastname: Straube
mesh_terms: D015360:Analgesia, Epidural / Q000009:adverse effects / Q000379:methods*; D016362:Analgesia, Obstetrical / Q000009:adverse effects / Q000379:methods*; D016058:Analgesia, Patient-Controlled / Q000009:adverse effects / Q000379:methods*; D000700:Analgesics / Q000008:administration & dosage* / Q000009:adverse effects; D001034:Apgar Score; D002585:Cesarean Section; D016009:Chi-Square Distribution; D005113:Extraction, Obstetrical; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D007263:Infusions, Parenteral; D048949:Labor Pain / Q000188:drug therapy*; D007743:Labor, Obstetric / Q000187:drug effects; D016017:Odds Ratio; D010147:Pain Measurement; D036801:Parturition / Q000187:drug effects; D017060:Patient Satisfaction; D011247:Pregnancy; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000700:Analgesics