Randomised controlled pilot study to investigate the effectiveness of thoracic epidural and paravertebral blockade in reducing chronic post-thoracotomy pain: TOPIC feasibility study protocol

Ropivacaine pharmacokinetics in the arterial and venous pools after ultrasound-guided continuous thoracic paravertebral nerve block

Background and Aims

Although thoracic paravertebral blockade (TPVB) is employed in thoracic surgery to ensure satisfactory postoperative analgesia, large doses of anesthetics are required and manifestations of local anesthetic systemic toxicity (LAST) may appear. Currently, there are limited data on the pharmacokinetics of ropivacaine after continuous TPVB. The aim of this prospective study was to investigate ropivacaine kinetics, in the arterial and venous pools, after continuous TPVB and assess the risk of LAST.

Material and Methods

Immediately after induction of general anesthesia, an ultrasound-guided continuous TPVB at T5 or T6 or T7 thoracic level was performed in 18 adult patients subjected to open thoracotomy. A 25-ml single bolus injection of ropivacaine 0.5% was administered through thoracic paravertebral catheter, followed by a 14 ml/h continuous infusion of ropivacaine 0.2% starting at the end of surgery. Quantification of total ropivacaine concentrations was performed using a validated high-performance liquid chromatography method. Population pharmacokinetic models were developed separately for arterial and venous ropivacaine data.

Results

The best model was one-compartment disposition with an additional pre-absorption compartment corresponding to thoracic paravertebral space. Gender had a significant effect on clearance, with females displaying lower elimination than males. Some patients had ropivacaine concentrations above the toxic threshold, but none displayed evidence of LAST. Continuous thoracic paravertebral nerve blocks provided adequate postoperative analgesia.

Conclusion

Ropivacaine doses at the upper end of clinical use (800 mg/d) did not inflict the manifestations of LAST and provided adequate postoperative pain control. Pharmacokinetic models were developed, and the effect of gender was identified.

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.

Randomised controlled trial to investigate the effectiveness of thoracic epidural and paravertebral blockade in reducing chronic post-thoracotomy pain (TOPIC): a pilot study to assess feasibility of a large multicentre trial

OBJECTIVES

Thoracotomy is considered one of the most painful surgical procedures. The incidence of chronic post-thoracotomy pain (CPTP) is up to 50%. Paravertebral blockade (PVB) may be superior to thoracic epidural blockade (TEB) in preventing CPTP. The specific objective of this pilot study was to assess the feasibility of conducting a larger trial to determine whether PVB at thoracotomy is more effective in reducing CPTP compared with TEB.

DESIGN

A randomised, parallel, external pilot study was conducted to assess whether a large randomised trial of TEB and PVB with CPTP as the primary outcome is feasible.

SETTING

Two adult thoracic centres in the UK.

PARTICIPANTS

All adult patients admitted for elective open thoracotomy. Participants were excluded if they were American Society of Anesthesiologists physical status IV or V; or if there is contraindication to local anaesthetics; infection near the proposed puncture site; coagulation/thoracic spine disorders; required chest wall resection or emergency thoracic surgery or had a previous thoracotomy.

RESULTS

All patients presenting for thoracotomy were screened over a 12-month period with 194 found to be eligible. Of these, 69 (36%) were randomised (95% CI 29% to 42%). Discounting five participants who died, 54 of 64 participants (84%) returned questionnaire booklets at 6 months. The number of participants indicating at least a moderate level of chest pain at 6 months was lower with PVB but with high levels of uncertainty (RR: 0.7; 95% CI 0.3 to 1.7 for worst pain; RR: 0.3; 95% CI 0.0 to 2.8 for average pain). There were no safety concerns.

CONCLUSIONS

A large, multicentre randomised controlled trial of PVB versus TEB is feasible as it is possible to randomise and follow up participants with high fidelity. Pain scores were lower on average with PVB compared with TEB but a much larger trial is required to confirm this reliably.

TRIAL REGISTRATION NUMBER

ISRCTN45041624.

Assessment of postoperative pain management and comparison of effectiveness of pain relief treatment involving paravertebral block and thoracic epidural analgesia in patients undergoing posterolateral thoracotomy

Background

TEA (thoracic epidural analgesia) is considered a basic method of analgesia used in thoracic surgeries. PVB (paravertebral block) is an alternative method. The thesis compares effectiveness of both methods in postoperative analgesia with particular focus on assessment of the postoperative pain management quality.

Methods

The study involved 2 groups of patients, each consisting of 30 patients undergoing posterolateral thoracotomy. The study group involved patients anesthetized applying PVB method, while the control group involved patients anesthetized with TEA. Hemodynamic and respiratory parameters as well as severity of pain assessed using NRS (numeric rating scale) during the first 3 days after the surgery, number of days of hospitalization, and the need to use additional pain relievers were taken into account in both groups. Evaluation of postoperative pain management quality was performed applying Clinical Quality Indicators in Postoperative Pain Management.

Results

No statistical significance was demonstrated between the groups in respect of hemodynamic and respiratory parameters values, the need to use additional pain relievers and the number of days of hospitalization. There was no statistically significant difference between the groups in respect of general assessment of pain management quality, except for the assessment of the lowest level of pain within the last 24 h of measurement. This result in TEA group was statistically significantly lower than the one in PVB group (p = 0.019).

Conclusions

In the assessment of postoperative pain management quality both analyzed methods are statistically significantly different only in the category of “lowest level of pain within the last 24 hours of measurement”, to the benefit of TEA group. No statistically significant difference has been observed between the two study groups with respect to the remaining parameters.

Trial registration

KB-0012/71/15. Date of registration 22 June 2015.

Paravertebral catheter analgesia for minimally invasive Ivor Lewis oesophagectomy

Background

Oesophagectomy is a major complex operation associated with significant morbidity and mortality. Epidural analgesia has long been the gold standard postoperative analgesia but is associated with side-effects like hypotension, epidural haematoma and infection. In an attempt to lower morbidity and enhance recovery postoperatively, we have adopted the use of paravertebral catheter analgesia (PVCA) for patients undergoing totally minimal invasive oesophagectomy (TMIO).

Methods

Our objective was to review the current literature about the use of both PVCA and epidural analgesia. In addition, we evaluated the effect of PVCA in a large group of patients undergoing TMIO for cancer. We reviewed the records of 100 consecutive patients who had a TMIO with PVCA, spinal morphine, and PCA. Prospective independent scoring of postoperative pain, length of stay, high-dependency unit (HDU) stay, PVCA failure, the use of patient-controlled analgesia (PCA), and the use of vasoconstrictor medication postoperatively was analysed.

Results

One hundred consecutive patients received PVCA with PCA after the TMIO. Catheter related failures occurred in 4 cases. The median pain score over each of the 5 days were 0. The average pain score was highest in the first 24 hours and decreased over the next 4 days postoperatively. The use of PCA was highest in the first 2 days and reduced daily over the subsequent 3 days. Seven patients required rescue analgesia in the form of intercostal nerve (ICN) block. Spinal morphine was successful in 94% of cases. Vasoconstrictors were required in 19% on day 1 and 3% on day 2, postoperatively.

Conclusions

Intraoperative placement of PVCA results in good postoperative pain control after a TMIO. This technique is simple, safe, reproducible and with very low failure rates. Therefore, it should be used instead of epidural catheter analgesia.

[Evaluation Index of Enhanced Recovery After Surgery: Status and Progress of Patient Report Outcomes in Thoracic Surgery]

加速康复外科临床应用的良好效果体现在降低围手术期并发症的发生率并缩短住院时间，但对围术期的患者症状管理及术后患者生活质量的关注不够高。从患者报告的资料角度评估临床疗效越来越受到重视。结合目前国内外关于病人报告结局的研究成果，本文系统论述了病人报告结局的概念内涵、研究意义及在胸外科的临床应用现状，提出借鉴国外病人报告的临床结局研究模式，开展有中国特色的结合学科特点的相关研究，并对已有的文献报告进行总结及分析。