The usefulness of dual channel elastomeric pump for intravenous patient-controlled analgesia in geriatrics: a randomized, double-blind, prospective study

Abstract

Background: Intravenous patient-controlled analgesia (IV-PCA) is often used in the postoperative period. However, determining an appropriate opioid dose is difficult. A previous study suggested the usefulness of variable-rate feedback infusion. In this study, we used a dual-channel elastomeric infusion pump to provide changes in PCA infusion rate by pain feedback.

Methods: Ninety patients undergoing orthopedic surgery of American Society of Anesthesiologists grade I-III and 65 to 79 years of age participated in the study. All patients were given a dual-chamber PCA. Patients were randomly allocated to a treatment group (Group D; PCA drugs divided into both chambers) or control group (Group C; PCA drugs only in the constant flow chamber with normal saline in the adjustable flow chamber). The primary outcome was the amount of fentanyl consumption via PCA bolus. The secondary outcome variables were pain score, total fentanyl consumption, rescue analgesic use, patient satisfaction, recovery scores, and adverse events including postoperative nausea and vomiting (PONV).

Results: Group D showed decreased fentanyl consumption of the PCA bolus, a decrease in rescue analgesic use, and better patient satisfaction compared with group C. The incidence of PONV was much higher in group C. There was no difference in other adverse events.

Conclusions: We showed the usefulness of dual chamber IV-PCA to change the flow rate related to pain feedback without any complications. Our results suggest a noble system that might improve existing IV-PCA equipment.

Trial registration: The study registered at UMIN clinical trial registry (registered date: 05/03/2020, registration number: UMIN000039702 ).

Keywords: Dual chamber device; Elastomeric pump; Geriatrics; Patient-controlled analgesia; Variable-rate feedback.

Fig. 1

A schematic of the dual chamber IV-PCA regimen. This figure shows the composition of the dual chamber IV-PCA device and our regimen. The IV-PCA consists of two channels: a basal-bolus channel with a fixed flow rate infusion and a bolus function, and the other selector channel has an adjustable flow rate without bolus function. Group D: PCA drugs were divided into both chambers. Group C: PCA drugs were contained only in the constant flow chamber and normal saline contained in the adjustable flow chamber

Fig. 2

Changes in pain scores in the postoperative periods. There were no significant differences in the pain scores observed between the two groups (p = 0.081, multivariate analysis). At 6 h after arrival in the PACU, the pain score in group D was lower than that in group C (p < 0.001). Group D: PCA drugs were divided into both chambers. Group C: PCA drugs were contained only in the constant flow chamber with normal saline contained in the adjustable flow chamber. The plot is represented by ‘mean with SEM’ instead of ‘mean with SD’ for visibility (See Table 3)

Fig. 3

Changes in fentanyl consumption in the postoperative periods. A Total fentanyl consumption. There were no differences in total fentanyl consumption (p = 0.315, multivariate analysis). B Fentanyl consumption via bolus. Fentanyl consumption used as boluses were different between the two groups (p < 0.001, multivariate analysis). The amounts of fentanyl administered as bolus during postoperative 1–6, 6–12, and 12–24 h were significantly lower in group D compared to group C. Group D: PCA drugs were divided into both chambers. Group C: PCA drugs were contained only in the constant flow chamber with normal saline contained in the adjustable flow chamber. The plot is represented by ‘mean with SEM’ instead of ‘mean with SD’ for visibility