The effect of continuous bilateral parasternal block with lidocaine on patient-controlled analgesia opioid requirement and recovery after open heart surgery: a double-blind randomised controlled trial

Abstract

Background

We hypothesised that a continuous 72-h bilateral parasternal infusion of lidocaine at 2×35 mg h⁻¹ would decrease pain and the inflammatory response after sternotomy for open heart surgery, subsequently improving quality of recovery.

Methods

We randomly allocated 45 participants to a 72-h bilateral parasternal infusion of lidocaine or saline commencing after wound closure. The primary outcome was the cumulative patient-controlled analgesia (PCA) morphine consumption at 72 h. Secondary outcomes included total morphine requirement, pain, peak expiratory flow, and serum interleukin-6 concentration. In addition, we used an eHealth platform for a 3-month follow-up of pain, analgesic use, and Quality of Recovery-15 scores.

Results

The 72-h PCA morphine requirement was significantly lower in the lidocaine than the saline group (10 mg [inter-quartile range: 5–19 mg] and 28.2 mg [inter-quartile range: 16–42.5 mg], respectively; P=0.014). The total morphine requirement (including morphine administered before the start of PCA) was significantly lower at 24, 48, and 72 h. Pain was well controlled with no difference in pain scores between treatment groups. The peak expiratory flow was lower in the lidocaine group at 72 h. Interleukin-6 concentrations showed no difference at 24, 48, or 72 h. Quality of Recovery-15 scores did not differ between treatment groups at any time during the 3-month follow-up.

Conclusions

After sternotomy for open heart surgery, a 72-h bilateral parasternal lidocaine infusion significantly decreased PCA and total morphine requirement. However, neither signs of decreased inflammatory response nor an improvement in recovery was seen.

Clinical trial registration

EudraCT number 2018-004672-35.