Lumbar paravertebral blockade as intractable pain management method in palliative care

Abstract

Optimal symptoms control in advanced cancer disease, with refractory to conventional pain treatment, needs an interventional procedure. This paper presents coadministration of local anesthetic (LA) via paravertebral blockade (PVB) as the alternative to an unsuccessful subcutaneous fentanyl pain control in a 71-year old cancer patient with pathological fracture of femoral neck, bone metastases, and contraindications to morphine. Bupivacaine in continuous infusion (0.25%, 5 mL · hour−1) or in boluses (10 mL of 0.125%–0.5% solution), used for lumbar PVB, resulted in pain relief, decreased demand for opioids, and led to better social interactions. The factors contributing to an increased risk of systemic toxicity from LA in the patient were: renal impairment; heart failure; hypoalbuminemia; hypocalcemia; and a complex therapy with possible drug-drug interactions. These factors were taken into consideration during treatment. Bupivacaine’s side effects were absent. Coadministered drugs could mask LA’s toxicity. Elevated plasma α1-acid glycoprotein levels were a protective factor. To evaluate the benefit-risk ratio of the PVB treatment in boluses and in constant infusion, bupivacaine serum levels were determined and the drug plasma half-lives were calculated. Bupivacaine’s elimination was slower when administered in constant infusion than in boluses (t½ = 7.80 hours versus 2.64 hours). Total drug serum concentrations remained within the safe ranges during the whole treatment course (22.9–927.4 ng mL−1). In the case presented, lumbar PVB with bupivacaine in boluses (≤ 137.5 mg · 24 hours−1) was an easy to perform, safe, effective method for pain control. Bupivacaine in continuous infusion (≤150 mg · 12 hours−1) had an acceptable risk-benefits ratio, but was ineffective.

Bupivacaine administered intrathecally versus rectally in the management of intractable rectal cancer pain in palliative care

“…In the Lapmahapaisan et al study on 25 patients with spinal anesthesia, 20 mL of 0.5% bupivacaine generated plasma drug concentrations equal to 176.30–1,383.99 ng/mL and was safe. 39 In our previous study, 42 a paravertebral blockage with 12.5–50 mg of bupivacaine in boluses (total daily dose was 137.50 mg) caused total plasma drug concentration to range from 22.9–573.5 ng/mL and provided for a safe, effective analgesia. On the other hand, bupivacaine concentrations in the 810–2,700 ng/mL range caused mild CNS toxicity (facial tingling, tinnitus, visual disturbances) in normal humans after IV bupivacaine infusion.…”