EP122 Remifentanil patient-controlled analgesic efficacy at different cervical dilations: a retrospective single-centre study

<h3>Background and Aims</h3> The analgesic effectiveness of remifentanil patient-controlled analgesia (Remifentanil-PCA) may vary based on the stage of labor and parity, potentially influencing satisfaction with labor analgesia. The primary aim was to evaluate the degree of pain reduction considering different cervical dilations in both nulliparous and multiparous women. <h3>Methods</h3> Women who were ≥37 weeks pregnant with singleton cephalic fetuses, either by spontaneous onset or induction of labor, were included. From the Labour Record form, demographic and obstetric data and the onset of analgesia categorized by cervical dilation (1–3 cm, 4–6 cm, 7–9 cm, and full dilation) were collected. From the Remifentanil-PCA form, analgesia onset and duration (the time interval between the start of analgesia and the delivery), initial Visual Analog Scale (VAS0), VAS after the first hour of analgesia (VAS1), the lowest VAS (VASmin), the pain reduction during the first hour of analgesia (VAS0 - VAS1), satisfaction with labor analgesia (dissatisfied, moderately or very satisfied), and the complication rates were obtained. <h3>Results</h3> 513 nulliparas and 523 multiparas who delivered between January-1 and December-31, 2019 were reviewed. No differences were found in age, BMI, labour induction, OP positioning, blood loss &gt;500 ml, or neonatal outcomes. Nulliparas exhibited a higher gestational age, longer labor duration, and increased CS and vacuum extractions rates. No differences were found in VAS0, VAS1, or pain intensity reduction (VAS₀ - VAS₁) regardless of the stage of labor or parity. A higher proportion of multiparas reported moderate (p &lt; 0.001) and high satisfaction (p &lt; 0.001) with remifentanil-PCA. Remifentanil-PCA consistently provided mild to moderate pain intensity reduction (figure 1). No serious complications were observed. <h3>Conclusions</h3> Remifentanil-PCA demonstrates consistent effectiveness regardless of the stage of labour or parity, suggesting that it can be administered at any point during labor. Its availability for immediate analgesic effect further enhances the flexibility of its use in clinical practice.