Continuous right thoracic paravertebral block following bolus initiation reduced postoperative pain after right-lobe hepatectomy: a randomized, double-blind, placebo-controlled trial

Abstract

Background and objectives: We hypothesized that continuous right thoracic paravertebral block, following bolus initiation, decreases opioid consumption after right-lobe hepatectomy in patients receiving patient-controlled intravenous analgesia with sufentanil.

Methods: Patients undergoing right-lobe hepatectomy with a right thoracic paravertebral catheter placed at T7 30 minutes before surgery were randomly assigned to receive through this catheter either a 10-mL bolus of 0.2% ropivacaine before emergence, followed by a continuous infusion of 6 mL/h for 24 hours (PVB group), or saline at the same scheme of administration (control group). All patients were started on patient-controlled intravenous analgesia with sufentanil in the postanesthesia care unit. The primary outcome measure was total sufentanil consumption during the first 24 postoperative hours. P = 0.05 was considered as significant. For the multiple comparisons of data at 5 different time points, the P value for the 0.05 level of significance was adjusted to 0.01.

Results: Sixty-six patients were assessed for eligibility, and a PVB catheter was successfully placed for 48 patients. Data were analyzed on 22 patients in group PVB and 22 patients in the control group. The cumulative sufentanil consumption in the PVB group (54.3 ± 12.1 μg) at 24 postoperative hours was more than 20% less than that of the control group (68.1 ± 9.9 μg) (P < 0.001). There was also a significant difference in pain scores (numerical rating scale) between groups, where the PVB group had lower scores than did the control group at rest and with coughing for the first 24 hours (P < 0.001).

Conclusions: Continuous right thoracic paravertebral block, following bolus initiation, has an opioid-sparing effect on sufentanil patient-controlled intravenous analgesia for right-lobe hepatectomy patients and reduces numerical rating scale pain scores at rest and with coughing in the first 24 postoperative hours.

Trial registration: ClinicalTrials.gov NCT01691937.

Conflict of interest statement

The authors declare no conflict of interest.

Figures

FIGURE 1

CONSORT patient flow diagram.

FIGURE 2

Cumulative sufentanil consumption in the first 24 postoperative hours. Data are presented as mean and SD. Differences of cumulative sufentanil consumption at each time point between the 2 groups were compared with repeated-measures ANOVA followed by Student t test. The Bonferroni correction was performed on the raw P value. Patients in the paravertebral group consumed less sufentanil than did patients in the control group at each time point.

FIGURE 3

Cumulative frequency of PCIA in the first 24 postoperative hours. Data were presented as mean and SD. Differences of cumulative frequency of PCIA at each time point between the 2 groups were compared with repeated-measures ANOVA followed by Student t test. The Bonferroni correction was performed on the raw P value. The cumulative frequency of PCIA at each time point in the control group was more compared with the paravertebral group.

FIGURE 4

Pain scores at rest in the first 24 postoperative hours. The NRS data are displayed in box-and-whisker plots. Median (quadrate in the box), interquartile range (box), and range not including outliers (error bars) are shown. Outliers (>1.5 box lengths) and extremes (>3 box lengths) are represented by circles and asterisks, respectively. Differences of NRS scores at each time point between the 2 groups were analyzed using the Mann-Whitney U test. The Bonferroni correction was performed on the raw P value. The NRS scores at rest at each time point in the control group were higher compared with the paravertebral group. NRS (0–10), where 0 indicates no pain, and 10 indicates the most severe pain.

FIGURE 5

Pain scores on coughing in the first 24 postoperative hours. The NRS data are displayed in box-and-whisker plots. Median (quadrate in the box), interquartile range (box), and range not including outliers (error bars) are shown. Outliers (>1.5 box lengths) and extremes (>3 box lengths) are represented by circles and asterisks, respectively. Differences of NRS scores at each time point between the 2 groups were analyzed using the Mann-Whitney U test. The Bonferroni correction was performed on the raw P value. The NRS scores on coughing at each time point in the control group were higher compared with the paravertebral group. NRS (0–10), where 0 indicates no pain, and 10 indicates the most severe pain.