Zhong W, Zhong Y, Zeng JX et al. Celiac plexus block for treatment of pain associated with pancreatic cancer: a meta-analysis. Pain Pract. doi:10.1111/papr.12083 (2013) (Epub ahead of print).
An analysis of 151 records for celiac plexus block (CPB) for pancreatic cancer pain was carried out. From these, 37 full-text articles were assessed and seven ultimately met the inclusion criteria. Outcomes were assessed comparing patients receiving intraoperative, percutaneous and endoscopic CPB, to those receiving pharmaceutical analgesia. Meta-analysis yielded a significant improvement in pain scores at 4 weeks in the CPB group, but not at 8 weeks. Analgesic drug use was also assessed. Those undergoing CPB received significantly less opioid analgesia at 4 weeks and also on the day before death. Funnel plot analysis was carried out and demonstrated no evidence of publication bias. The adverse events reported most frequently were transient diarrhea and transient orthostatic hypotension.
– Written by Michael A Erdek
Mueller O, Diener HC, Danmann P et al. Occipital nerve stimulation for intractable chronic cluster headache or migraine: a critical analysis of direct treatment costs and complications. Cephalalgia doi:10.1177/0333102413493193 (2013) (Epub ahead of print).
Analysis was carried out on 27 patients with chronic cluster headache (n = 24) or chronic migraine (n = 3), who underwent temporary percutaneous trial followed by implantation of occipital nerve stimulation. Follow-up, carried out over a mean of 20 months, demonstrated that 93% of patients were responsive to treatment. Chronic migraine patients experienced a decrease in mean headache days from 27 to 20 and at least a 50% decrease in duration of headache attack. Chronic cluster headache patients experienced a decrease in mean daily attacks from five per day at a mean score of 8, down to three per day at a mean score of 5. There were 21 complications in 14 patients, requiring 13 reoperations. The most common causes for reoperation were local pain, lead breakage and infection. Per-case cost analysis yielded a cost of €28,186 (€9445 for hospitalization and €18,741 for hardware expenses).
– Written by Michael A Erdek
Nash P, Wiley K, Brown J et al. Functional magnetic resonance imaging identifies somatotopic organization of nociception in the human spinal cord. Pain 154, 776–781 (2013).
This is a very innovative report of the development of functional MRI technology to allow for imaging of the cervical spinal cord during the processing of acute heat pain information in normal volunteers. Very sophisticated methods of eliminating artifacts are required; whether or not others can replicate these steps in data analysis is unclear to this reader. Furthermore, the resolution size is 1.25 × 1.25 × 4 mm3, which is not capable of showing the lamination of the dorsal horn, although it does indicate the segmental innervation and discriminates between C-4 and C-6 inputs. In this report, the authors did not attempt to use different modalities of sensation, but exclusively used a heat stimulus reported by the patient as 7 on a 0–10 scale, which was contrasted with a warm, but not noxious, stimulus. This is, I suspect, the first of a series of reports on functional MRI of the spinal cord from a very successful laboratory. We should remember, however, that these studies have been carried out on normal volunteers and that they are, therefore, only relevant to acute pain until it has been shown that the same anatomical pathways and functional status are present in those who suffer from chronic pain.
– Written by John D Loeser
Perlas A, Kirkham KR, Billing R et al. The impact of analgesic modality on early ambulation following total knee arthroplasty. Reg. Anesth. Pain Med. 38(4), 334–339 (2013).
In this retrospective cohort study, the authors examined the analgesic and rehabilitation outcomes associated with 48-h continuous femoral nerve block, local infiltration analgesia or local infiltration analgesia plus adductor canal nerve block in patients undergoing a total knee arthroplasty under spinal anesthesia. Associated with moderate-to-severe pain, effective analgesia is essential to facilitate postoperative recovery in this patient population.
The authors retrospectively assessed patients undergoing total knee arthroplasty under spinal anesthesia in an 8-month period with a targeted review of 100 patients per group. The team reviewed records of eligible patients to identify the analgesic technique used and the primary outcome of distance walked on the first day after the operation. Secondary outcomes included: numeric rating pain scale scores, ambulation on the second and third postoperative days, opioid consumption, adverse effects and discharge disposition.
The authors observed that in the 298 eligible patients reviewed, patients treated with local infiltration analgesia and local infiltration plus adductor canal block demonstrated longer distances walked on the first day following operation than patients treated with continuous femoral nerve block (median values of 20, 30 and 0 m, respectively; p < 0.0001). The addition of the adductor canal block was associated with further improvement in early ambulation benchmarks and a higher rate of home discharge compared with local infiltration (88.2 vs 73.2%; p = 0.018). The authors reported that local infiltration, with or without adductor canal block, was associated with lower opioid consumption than continuous femoral nerve infusion and lower pain scores at rest and during movement for the first 24 h.
The study suggests that local infiltration analgesia is associated with improved early analgesia and ambulation, and that the addition of adductor canal nerve block is associated with further improvements in early ambulation and a greater incidence of home discharge.
– Written by Dominic Chamberlain
Fredrickson Fanzca MJ, Danesh-Clough TK, White R. Adjuvant dexamethasone for bupivacaine sciatic and ankle blocks: results from 2 randomized placebo-controlled trials. Reg. Anesth. Pain Med. 38(4), 300–307 (2013).
In this study, the authors performed two prospective, randomized, double-blind, placebo-controlled trials to assess whether the addition of dexamethasone 8 mg to bupivacaine for sciatic and ankle blocks prolonged block duration, thereby improving postoperative analgesia. A local anesthetic adjuvant, dexamethasone, has been demonstrated to prolong the time to first postoperative pain and improve postoperative analgesia following upper-limb brachial plexus block. However, a lack of systematically administered dexamethasone in controls in previous studies limits any potential interpretations.
Study participants were made up of 126 patients presenting for elective foot/ankle surgery under ankle (n = 60) or sciatic blocks (n = 66). The patients received 30 ml bupivicaine 0.5% plus dexamethasone 8 mg or saline 2 ml, with alternate solutions administered by intramuscular injection into the ipsilateral thigh. The authors assessed pain onset, numerically rated pain and supplementary tramadol consumption at 24 and 48 h.
The study results demonstrated that fewer dexamethasone group patients experienced pain at 24 h (13 vs 47%; p = 0.01), which was supported by multiple post hoc analyses for pain from 20 to 34 h in the sciatic study. In the ankle block study, no benefit was observed at any time. Pain-free survival curves for the first 48 h were not significantly different between groups in both studies and pooled analysis of the two studies further supported an absence of a significant dexamethasone effect (hazard ratio: 0.81; 95% CI: 0.58–1.53; p = 0.94). There were no differences between groups for worst and average pain, the requirement for tramadol and patient satisfaction.
The study demonstrated that substitution of systemic dexamethasone for perineural dexamethasone during bupivacaine sciatic and ankle blocks only had a minor analgesic enhancing effect. Considered in context alongside recent animal studies demonstrating dexamethasone neurotoxicity, the authors concluded that the perineural route for dexamethasone administration requires re-evaluation.
– Written by Dominic Chamberlain
Financial & competing interests disclosure
D Chamberlain is an employee of Future Science Group. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
No writing assistance was utilized in the production of this manuscript.