Boselli et al.  are to be congratulated on their excellent study of patient-controlled epidural analgesia in labor.1The merit of a background infusion in addition to boluses of epidural solution on patient demand has been contested for many years.2,3The finding by Ferrante et al.  that some rates of infusion appeared to reduce the requirement for additional supplementary boluses4may have influenced North American practice, where continuous infusion techniques are popular and physician workload is an important issue.5In contrast, demand-only patient-controlled epidural analgesia is also associated with good efficacy and high maternal satisfaction. Even in countries where midwife-administered supplementation is not permitted, such as Belgium, patient-controlled epidural analgesia is usually delivered without a background infusion (verbal communication, May, 2004, Marc Van de Velde, M.D., Ph.D., Professor, Department of Anesthesiology, U.Z. Gasthuisberg, Leuven, Belgium).

Boselli et al.  are incorrect, however, in stating that only two studies have previously compared the efficacy and local anesthetic consumption of patient-controlled epidural analgesia with or without background infusion. I conducted the first of such studies in 1991 and no benefit from a background infusion was found, albeit in a small sample (n = 52) and with only one rate of background infusion (4 ml/h).6 

Although it is an oversimplification to suggest that “one regimen fits all” for patient-controlled epidural analgesia during labor, Boselli et al.  provide more compelling evidence that the routine use of a background infusion is not beneficial; indeed that it increases drug consumption and cost without improving maternal comfort or satisfaction.

University of Western Australia and King Edward Memorial Hospital for Women, Perth, Australia.

Boselli E, Debon R, Cimino Y, Rimmele T, Allaouchiche B, Chassard D: Background infusion is not beneficial during labor patient-controlled analgesia with 0.1% ropivacaine plus 0.5 μg/ml sufentanil. Anesthesiology 2004;100:968–72
Paech MJ: Patient controlled epidural analgesia for labor (letter). Anesth Analg 1995; 80:1064
White PF, Gambling DR, Parker RK: Role of continuous background infusion with patient-controlled analgesia (letter). Anesth Analg 1995; 80:646
Ferrante FM, Rosinia FA, Gordon C, Datta S: The role of continuous background infusions in patient-controlled epidural analgesia for labor and delivery. Anesth Analg 1994; 79:80–4
D’Angelo R: Epidural PCA during labor. ASA Newsletter 2001; 65:116–8
Paech MJ: Patient-controlled epidural analgesia in labour: Is a continuous infusion of benefit? Anaesth Intensive Care 1992; 20:15–20