[Continuous paravertebral analgesia versus intravenous analgesia in minimally invasive cardiac surgery by mini-thoracotomy]

Local anesthetic dosing and toxicity of adult truncal catheters: a narrative review of published practice

BACKGROUND/IMPORTANCE

Anesthesiologists frequently use truncal catheters for postoperative pain control but with limited characterization of dosing and toxicity.

OBJECTIVE

We reviewed the published literature to characterize local anesthetic dosing and toxicity of paravertebral and transversus abdominis plane catheters in adults.

EVIDENCE REVIEW

We searched the literature for bupivacaine or ropivacaine infusions in the paravertebral or transversus abdominis space in humans dosed for 24 hours. We evaluated bolus dosing, infusion dosing and cumulative 24-hour dosing in adults. We also identified cases of local anesthetic systemic toxicity and toxic blood levels.

FINDINGS

Following screening, we extracted data from 121 and 108 papers for ropivacaine and bupivacaine respectively with a total of 6802 patients. For ropivacaine and bupivacaine, respectively, bolus dose was 1.4 mg/kg (95% CI 0.4 to 3.0, n=2978) and 1.0 mg/kg (95% CI 0.18 to 2.1, n=2724); infusion dose was 0.26 mg/kg/hour (95% CI 0.06 to 0.63, n=3579) and 0.2 mg/kg/hour (95% CI 0.06 to 0.5, n=3199); 24-hour dose was 7.75 mg/kg (95% CI 2.1 to 15.7, n=3579) and 6.0 mg/kg (95% CI 2.1 to 13.6, n=3223). Twenty-four hour doses exceeded the package insert recommended upper limit in 28% (range: 17%-40% based on maximum and minimum patient weights) of ropivacaine infusions and 51% (range: 45%-71%) of bupivacaine infusions. Toxicity occurred in 30 patients and was associated with high 24-hour dose, bilateral catheters, cardiac surgery, cytochrome P-450 inhibitors and hypoalbuminemia.

CONCLUSION

Practitioners frequently administer ropivacaine and bupivacaine above the package insert limits, at doses associated with toxicity. Patient safety would benefit from more specific recommendations to limit excessive dose and risk of toxicity.

Postoperative pain treatment with erector spinae plane block and pectoralis nerve blocks in patients undergoing mitral/tricuspid valve repair - a randomized controlled trial

Background

Effective postoperative pain control remains a challenge for patients undergoing cardiac surgery. Novel regional blocks may improve pain management for such patients and can shorten their length of stay in the hospital.

To compare postoperative pain intensity in patients undergoing cardiac surgery with either erector spinae plane (ESP) block or combined ESP and pectoralis nerve (PECS) blocks.

Methods

This was a prospective, randomized, controlled, double-blinded study done in a tertiary hospital. Thirty patients undergoing mitral/tricuspid valve repair via mini-thoracotomy were included. Patients were randomly allocated to one of two groups: ESP or PECS + ESP group (1:1 randomization). Patients in both groups received a single-shot, ultrasound-guided ESP block. Participants in PECS + ESP group received additional PECS blocks. Each patient had to be extubated within 2 h from the end of the surgery. Pain was treated via a patient-controlled analgesia (PCA) pump. The primary outcome was the total oxycodone consumption via PCA during the first postoperative day. The secondary outcomes included pain intensity measured on the visual analog scale (VAS), patient satisfaction, Prince Henry Hospital Pain Score (PHHPS), and spirometry.

Results

Patients in the PECS + ESP group used significantly less oxycodone than those in the ESP group: median 12 [interquartile range (IQR): 6–16] mg vs. 20 [IQR: 18–29] mg (p = 0.0004). Moreover, pain intensity was significantly lower in the PECS + ESP group at each of the five measurements during the first postoperative day. Patients in the PECS + ESP group were more satisfied with pain management. No difference was noticed between both groups in PHHPS and spirometry.

Conclusions

The addition of PECS blocks to ESP reduced consumption of oxycodone via PCA, reduced pain intensity on the VAS, and increased patient satisfaction with pain management in patients undergoing mitral/tricuspid valve repair via mini-thoracotomy.

Trial registration

The study was registered on the 19th July 2018 (first posted) on the ClinicalTrials.gov identifier: NCT03592485.

Bilateral thoracic paravertebral block combined with general anesthesia vs. general anesthesia for patients undergoing off-pump coronary artery bypass grafting: a feasibility study

BACKGROUND

Whether thoracic paravertebral block (PVB) is useful in patients undergoing off-pump coronary artery bypass grafting (OPCABG) remains unknown. This study aimed to investigate the feasibility of bilateral PVB combined with general anesthesia (GA) in patients undergoing OPCABG.

METHODS

This feasibility study assessed 60 patients scheduled for OPCABG at the Qingdao Municipal Hospital in 2016-2017. Patients were randomly assigned to receive nerve stimulator-guided bilateral PVB combined with GA (PVB + GA) or GA alone (n = 30/group). Patients were asked to rate rest and cough pain hourly after the surgery. The primary endpoint was the visual analogue scale (VAS) pain score within 48 h postoperatively. Secondary endpoints were rescue analgesia and morphine consumption, fentanyl dose within 48 h postoperatively, as well as operative time, time to extubation, intensive care unit (ICU) stay, hospital stay and other postoperative adverse events.

RESULTS

Both rest and cough pains were lower in the PVB + GA group at 12, 24, 36, and 48 h after surgery compared with the GA group. There were fewer patients who needed rescue analgesia in the PVB + GA group at 12 and 24 h than in the GA group. Morphine consumptions at 24 and 48 h were lower in the PVB + GA group compared with the GA group. Time to extubation (P = 0.035) and ICU stay (P = 0.028) were shorter in the PVB + GA group compared with the GA group. AEs showed no differences between the two groups.

CONCLUSIONS

Nerve stimulator-guided bilateral thoracic PVB combined with GA in OPCABG is associated with a reduced rescue analgesia and morphine consumption, compared to GA.

A case series of continuous paravertebral block in minimally invasive cardiac surgery

Background

Minimally invasive cardiac surgery (MICS), via minithoracotomy, is thought to be a fast track to extubation and recovery after surgery. For this, good coverage analgesia is essential. Epidural anesthesia, a standard technique for thoracic surgery, has high risk of complications, such as epidural abscess and spinal hematoma in open-heart surgery. Based on the hypothesis that continuous paravertebral block (CPVB), a less invasive regional anesthetic technique, is safe and effective in open-heart surgery, we applied CPVB to MICS with thoracotomy.

Findings

To assess whether CPVB could be used in open-heart surgery with fewer potential complications, we investigated our medical records of the 87 adult patients who underwent MICS at Akashi Medical Center, Hyogo, Japan, between March 2009 and May 2016. We collected data of CPVB-related complications, postextubation respiratory failure, duration of intubation, and other analgesic use from hospital clinical records. We observed no severe CPVB-related complications, such as hematoma, neuropathy, or abscess. PT-INR longer than 1.1 was associated with CPVB-related minor bleeding. Forty-three patients (47.4%) were extubated within 1 h after surgery, and there were no postextubation respiratory failures in any patients.

Conclusions

We observed no cases of severe CPVB-related complications or postextubation respiratory failure in any of our patients who underwent MICS. Preoperative prolongation of PT-INR was associated with CPVB-related minor bleeding.

Continuous bilateral thoracic paravertebral blockade for analgesia after cardiac surgery: a randomised, controlled trial

BACKGROUND

Continuous bilateral thoracic paravertebral blockade has been used for analgesia after cardiac surgery, but its efficacy has never been formally tested.

METHOD

Fifty adult patients were enrolled in a double-blind, randomised, controlled study of continuous bilateral thoracic paravertebral infusion of 0.5% lidocaine (1 mg.kg^-1.hr^-1) for analgesia after coronary surgery. Control patients received a subcutaneous infusion of lidocaine at the same rate through catheters inserted at the same locations as the study group. The primary outcome was morphine consumption at 48 hours using patient-controlled analgesia (PCA). Secondary outcomes included pain, respiratory function, nausea and vomiting. Serum lidocaine concentrations were measured on the first two post-operative days.

RESULTS

There was no difference in morphine consumption or in any other outcome measure between the groups. Serum lidocaine concentrations increased during the study, with a maximum of 5.9 mg.l^-1. There were no adverse events as a consequence of the study.

CONCLUSION

Bilateral paravertebral infusion of lidocaine confers no advantage over systemic lidocaine infusion after cardiac surgery.

CLINICAL TRIAL REGISTRATION

ISRCTN13424423 ( https://www.isrctn.com ).

Does Paravertebral Blockade Facilitate Immediate Extubation after Totally Endoscopic Robotic Mitral Valve Repair Surgery?

Objective

Immediate extubation of select patients in the operating room after cardiac surgery has been shown to be safe and may result in improved hemodynamics and decreased cost perioperatively. The aim of this study was to evaluate whether the addition of paravertebral blockade (PVB) to general anesthesia facilitates extubation in the operating room in patients undergoing totally endoscopic robotic mitral valve repair (TERMR).

Methods

A review of 65 consecutive patients who underwent TERMR between January 2012 and June 2013 at a single institution was conducted. Patients were divided into two groups, one group that received PVB and general anesthesia and a second group that received general anesthesia alone. The data analyzed included quantities of anesthetic administered during surgery and the location of extubation after surgery.

Results

A total of 34 patients received PVB and general anesthesia, whereas 31 received general anesthesia alone. The two groups had similar demographic and surgical data. Patients in the PVB and general anesthesia group were more likely to be extubated in the operating room (67.6%, n = 23 vs 41.9%, n = 13, P = 0.048) and required less intraoperative fentanyl (3.41 μg/kg vs 4.90 μg/kg, P = 0.006). There were no adverse perioperative events in either group related to PVB or extubation.

Conclusions

The addition of PVB to general anesthesia for perioperative pain control facilitated extubation in the operating room in patients undergoing TERMR. Paravertebral blockade allowed for lower intraoperative fentanyl dosing, which may account for the increased incidence of immediate extubation. A detailed prospective study is warranted.