Peak plasma concentration of total and free bupivacaine after erector spinae plane and pectointercostal fascial plane blocks

Blood bupivacaine concentrations after pecto-serratus and serratus anterior plane injections of plain and liposomal bupivacaine in robotically-assisted mitral valve surgery: Sub-study of a randomized trial

STUDY OBJECTIVE

To investigate the timing of peak blood concentrations and potential toxicity when using a combination of plain and liposomal bupivacaine for thoracic fascial plane blocks.

DESIGN

Pharmacokinetic analysis.

SETTING

Operating room.

PATIENTS

Eighteen adult patients undergoing robotically-assisted mitral valve surgery.

INTERVENTIONS

Ultrasound-guided pecto-serratus and serratus anterior plane blocks using a mixture of 0.5% bupivacaine HCl up to 2.5 mg/kg and liposomal bupivacaine up to 266 mg.

MEASUREMENTS

Arterial plasma bupivacaine concentration.

MAIN RESULTS

Samples from 13 participants were analyzed. There was substantial inter-patient variability in plasma concentrations. A geometric mean maximum bupivacaine concentration was 1492 ng/ml (range 660 to 4650 ng/ml) at median time of 30 min after injection. In 4/13 (31%) patients, plasma bupivacaine concentrations exceeded our predefined 2000 ng/ml toxic threshold. A second much smaller peak was observed about 32 h after the injection. No obvious signs of local anesthetic toxicity were observed.

CONCLUSIONS

Combined injection of plain and liposomal bupivacaine for pecto-serratus/serratus anterior plane blocks produced a biphasic pattern, with the highest arterial plasma concentrations observed within 30 min. Maximum concentrations exceeded the potential toxic threshold in nearly a third of patients, but without clinical evidence of toxicity. Clinicians should not assume that routine combinations of plain and liposomal bupivacaine for thoracic fascial plane blocks are inherently safe.

Serum Levels of Bupivacaine After Bilateral Ultrasound-Guided Deep Parasternal Intercostal Plane Block in Cardiac Surgery with Median Sternotomy

OBJECTIVE

To evaluate systemic levels of bupivacaine after bilateral ultrasound-guided deep parasternal intercostal plan (PIP) block in cardiac surgical patients undergoing median sternotomy.

DESIGN

Prospective, observational study SETTING: Single institution; academic university hospital PARTICIPANTS: Twenty-eight adult patients undergoing cardiac surgery with median sternotomy received a PIP block with 2.5 mg/kg bupivacaine with or without dexamethasone and dexmedetomidine.

MEASUREMENTS

Arterial blood samples were analyzed for total serum bupivacaine concentration at 5, 15, 30, 45, 60, 90, 120, and 150 minutes after placement of PIP. Local anesthetic volume, local anesthetic adjuncts, time to extubation, postoperative pain scores, and opioid consumption were recorded.

MAIN RESULTS

The mean peak bupivacaine concentration was 0.60 ± 0.62 µg/mL, and the mean time to maximum concentration (Tmax) was 16.92 ± 12.97 minutes. Two patients (7.1%) had a concentration >2.0 µg/mL within 15 minutes of block placement. The mean Tmax of bupivacaine was significantly greater in patients who did not receive additives compared to those patients who did (22.86 ± 14.77 minutes v 10.0 ± 5.22 minutes; p = .004). The times to extubation and postoperative pain were not improved with additives.

CONCLUSIONS

Bilateral PIP placed at the end of cardiac surgery resulted in low systemic bupivacaine levels. The inclusion of additives shortened Tmax without improving outcome.

Superficial parasternal intercostal plane blocks in cardiac surgery: a systematic review and meta-analysis

PURPOSE

Traditional multimodal analgesic strategies have several contraindications in cardiac surgery patients, forcing clinicians to use alternative options. Superficial parasternal intercostal plane blocks, anesthetizing the anterior cutaneous branches of the thoracic intercostal nerves, are being explored as a straightforward method to treat pain after sternotomy. We sought to evaluate the literature on the effects of superficial parasternal blocks on pain control after cardiac surgery.

METHODS

We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs). We searched MEDLINE, Embase, CENTRAL, and Web of Science databases for RCTs evaluating superficial parasternal intercostal plane blocks in adult patients undergoing cardiac surgery via midline sternotomy published from inception to 11 March 2022. The prespecified primary outcome was opioid consumption at 12 hr. The risk of bias was assessed with the Cochrane Collaboration Risk of Bias Tool, and the quality of evidence was evaluated using the grading of recommendations, assessments, development, and evaluations. Outcomes were analyzed with a random-effects model. All subgroups were prespecified.

RESULTS

We reviewed 1,275 citations. Eleven RCTs, comprising 756 patients, fulfilled the inclusion criteria. Only one study reported the prespecified primary outcome, precluding the possibility of meta-analysis. This study reported a reduction in opioid consumption (-11.2 mg iv morphine equivalents; 95% confidence interval [CI], -8.2 to -14.1) There was a reduction in opioid consumption at 24 hr (-7.2 mg iv morphine equivalents; 95% CI,  -5.6 to -8.7; five trials; 436 participants; moderate certainty evidence). All five studies measuring complications reported that none were detected, which included a sample of 196 blocks.

CONCLUSION

The literature suggests a potential benefit of using superficial parasternal blocks to improve acute postoperative pain control after cardiac surgery via midline sternotomy. Future studies specifying dosing regimens and adjuncts are required.

STUDY REGISTRATION

PROSPERO (CRD42022306914); first submitted 22 March 2022.

Comparative retrospective review of perioperative analgesia using ultrasound-guided programmed intermittent erector spinae plane block for video-assisted thoracoscopic lobectomy

BACKGROUND

The retrospective cohort study was conducted to estimate the opioid-sparing anesthesia and limited side-effects with ultrasound (US)-guided ESPB using programmed intermittent bolus (PIB) or continuous infusion (CI) and standard opioid-based anesthesia in patients undergoing video-assisted thoracoscopic lobectomy (VATS).

METHODS

Patients underwent VATS were stratified into either control group or one of the two ESPB groups in a 1:2:2 ratio depending on whether PIB was implemented or not. The primary endpoint was intra- and post-operative opioids consumption over the first 48 h following surgery.

RESULTS

A total of 180 cases were included in the analysis. Cumulative perioperative opioid administration was found to be significantly different between PIB, CI and control group (both p < 0.001), and between PIB and CI group (p = 0.028). More specifically, the mean was 305.30 ± 51.35 mg, 339.68 ± 56.07 mg and 468.91 ± 79.84 mg in PIB, CI and control group. NRS scores at rest across all postoperative times were comparable in two ESPB groups, while significantly lower than control group, however, scores during exercising at postoperative 3, 6, 12 h were significantly lower in PIB group as compared to CI group. A wider anesthetized dermatomes with PIB was observed at 6, 24 and 48 h as opposed to the CI. The mean of levobupivacaine plasma concentration was significantly lower for PIB at postoperative 0.5, 12, 24 and 48 h after initiation than CI. However, local anesthetic toxicity was not observed in any of the two ESPB groups.

CONCLUSIONS

When US-guided ESPB using PIB was performed preoperatively, it contributed to the minimization of intra- and post-operative opioid consumption due to better analgesia with a wider anesthetic dermatome opposed to conventional CI, whereas, it was also associated with lower risk of local anesthetic toxicity because of lower plasma concentration of levobupivacaine.

Erector spinae plane block: the ultimate 'plan A' block?

The erector spinae plane block (ESPB) is one of seven 'Plan A' blocks proposed by Regional Anaesthesia UK, covering the key areas of commonly encountered surgeries and acute pain. Unlike the other six blocks, the ESPB can be performed at all levels of the spine and provides analgesia to most regions of the body, leading to the argument that the ESPB is the ultimate Plan A block. Current studies show a high level of evidence supporting use in thoracoabdominal surgery but a lack of benefit in upper and lower limb surgery compared with local infiltration and other Plan A blocks. Thus, there is insufficient evidence to support the claim that the erector spinae plane block is the ultimate Plan A block.