Chester C. Buckenmaier

Pain and combat injuries in soldiers returning from Operations Enduring Freedom and Iraqi Freedom: implications for research and practice.

Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) have resulted in a growing number of seriously injured soldiers who are evacuated to the United States for comprehensive medical care. Trauma-related pain is an almost universal problem among these war-injured soldiers, and several military and Department of Veterans Affairs initiatives have been implemented to enhance pain care across the continuum of medical services. This article describes several innovative approaches for improving the pain care provided to OEF and OIF military personnel during acute stabilization, transport, medical-surgical treatment, and rehabilitation and presents summary data characterizing the soldiers, pain management services provided, and associated outcomes. We also identify some of the pain assessment, classification, and treatment challenges emerging from work with this population and provide recommendations for future research and practice priorities.

Randomized Placebo-Controlled Study Evaluating Lateral Branch Radiofrequency Denervation for Sacroiliac Joint Pain

Background:Sacroiliac joint pain is a challenging condition accounting for approximately 20% of cases of chronic low back pain. Currently, there are no effective long-term treatment options for sacroiliac joint pain. Methods:A randomized placebo-controlled study was conducted in 28 patients with injection-diagnosed sacroiliac joint pain. Fourteen patients received L4–L5 primary dorsal rami and S1–S3 lateral branch radiofrequency denervation using cooling-probe technology after a local anesthetic block, and 14 patients received the local anesthetic block followed by placebo denervation. Patients who did not respond to placebo injections crossed over and were treated with radiofrequency denervation using conventional technology. Results:One, 3, and 6 months after the procedure, 11 (79%), 9 (64%), and 8 (57%) radiofrequency-treated patients experienced pain relief of 50% or greater and significant functional improvement. In contrast, only 2 patients (14%) in the placebo group experienced significant improvement at their 1-month follow-up, and none experienced benefit 3 months after the procedure. In the crossover group (n = 11), 7 (64%), 6 (55%), and 4 (36%) experienced improvement 1, 3, and 6 months after the procedure. One year after treatment, only 2 patients (14%) in the treatment group continued to demonstrate persistent pain relief. Conclusions:These results provide preliminary evidence that L4 and L5 primary dorsal rami and S1–S3 lateral branch radiofrequency denervation may provide intermediate-term pain relief and functional benefit in selected patients with suspected sacroiliac joint pain. Larger studies are needed to confirm these results and to determine the optimal candidates and treatment parameters for this poorly understood disorder.

Randomized, Double-blind, Placebo-controlled, Dose- response, and Preclinical Safety Study of Transforaminal Epidural Etanercept for the Treatment of Sciatica

Background:Recent evidence implicates the inflammatory cytokine tumor necrosis factor as a major cause of radiculopathy. Yet, whereas open-label studies with systemically delivered tumor necrosis factor inhibitors have yielded positive results, a placebo-controlled study failed to demonstrate efficacy. One variable that may have contributed to poor outcomes is low drug levels at the site of nerve inflammation. To date, no studies have evaluated the efficacy or safety of epidurally administered anti-tumor necrosis factor agents. Methods:A double-blind, placebo-controlled, dose-response study was conducted to evaluate an epidural tumor necrosis factor inhibitor. Twenty-four patients with subacute lumbosacral radiculopathy were randomly assigned to receive two transforaminal epidural injections of 2, 4, or 6 mg of entanercept 2 weeks apart in successive groups of eight. In each group, two patients received epidural saline. A parallel epidural canine safety study was conducted using the same injection doses and paradigm as in the clinical study. Results:The animal and human safety studies revealed no behavioral, neurologic, or histologic evidence of drug-related toxicity. In the clinical arm, significant improvements in leg and back pain were collectively noted for the etanercept-treated patients, but not for the saline group, one month after treatment. One patient in the saline group (17%), six patients in the 2-mg group (100%), and four patients each in the 4-mg and 6-mg groups (67%) reported at least 50% reduction in leg pain and a positive global perceived effect one month after treatment. Six months after treatment, the beneficial effects persisted in all but one patient. Conclusion:Epidural entanercept holds promise as a treatment for lumbosacral radiculopathy.

A double-blind, placebo-controlled, dose-response pilot study evaluating intradiscal etanercept in patients with chronic discogenic low back pain or lumbosacral radiculopathy.

Background:In recent years, convincing evidence has emerged implicating tumor necrosis factor α as a causative factor in radiculopathy and discogenic back pain. But although preliminary open-label studies demonstrated promising results for the treatment of low back pain with tumor necrosis factor-α inhibitors, early optimism has been tainted by a controlled study showing no significant benefit in sciatica. To determine whether outcomes might be improved by a more direct route of administration, the authors evaluated escalating doses of intradiscal etanercept in 36 patients with chronic lumbosacral radiculopathy or discogenic low back pain. Methods:A double-blind, placebo-controlled pilot study was conducted whereby six patients received 0.1, 0.25, 0.5, 0.75, 1.0, or 1.5 mg etanercept intradiscally in each pain-generating disc. In each escalating dose group of six patients, one received placebo. A neurologic examination and postprocedure leukocyte counts were performed in all patients at 1-month follow-up visits. In patients who experienced significant improvement in pain scores and function, follow-up visits were conducted 3 and 6 months after the procedure. Results:At 1-month follow-up, no differences were found for pain scores or disability scores between or within groups for any dose range or subgroup of patients. Only eight patients remained in the study after 1 month and elected to forego further treatment. No complications were reported, and no differences were noted between preprocedure and postprocedure leukocyte counts. Conclusions:Although no serious side effects were observed in this small study, a single low dose of intradiscal etanercept does not seem to be an effective treatment for chronic radicular or discogenic low back pain.

Continuous peripheral nerve block for battlefield anesthesia and evacuation

Peripheral nerve and continuous peripheral nerve block (CPNB) have the potential to be valuable techniques in combat anesthesia. We describe the first successful application of CPNB in the pain management and surgical management of a combat casualty as he was evacuated from the Iraqi battlefield to the United States.

Pain Following Battlefield Injury and Evacuation: A Survey of 110 Casualties from the Wars in Iraq and Afghanistan

OBJECTIVE Advances in regional anesthesia, specifically continuous peripheral nerve blocks (CPNBs), have greatly improved pain outcomes for wounded soldiers in Iraq and Afghanistan. pain management practice variations, however, do exist, depending on the availability of pain-trained military professionals deployed to combat support hospitals. an exploratory study was undertaken to examine pain and other outcomes during evacuation and at landstuhl regional medical center (lrmc), germany. DESIGN a mixed-methods, semistructured interview survey design was conducted on a convenience sample of wounded u.s. soldiers evacuated from iraq and afghanistan to lrmc. setting and patients. a total of 110 wounded soldiers evacuated from IRAQ and Afghanistan from July 2007 to February 2008 completed a pain survey at LRMC. Data were collected on demographics, injury mechanism, last 24-hour average, least, and worst, and pain now by using a 0-10 scale, and percent pain relief (from 0% [No relief] to 100% [Complete relief]). Similar items and measures of anxiety, distress, and worry during flight transport were measured (from 0 [None] to 10 [Extreme]). Responses were analyzed by using descriptive and correlational statistics, multiple linear regression, Mann-Whitney U-tests, and t-tests. The Walter Reed Army Medical Center, Human Use Committee approved this investigation. RESULTS Participants were typically male (99.1%), Caucasian (80%), and injured from improvised explosive devices (60%) and gunshots (21.8%). Average and worst pain scores were inversely correlated with pain relief during transport (r = -0.58 and r = -0.46, respectively; P < 0.001), and low to moderately positively correlated with increased anxiety, distress, and worry during transport (P < 0.05). Average percent pain relief achieved was 45.2% +/- 26.6% during transport and 64.5% +/- 23.5% while at LRMC (P < 0.001). Participants with CPNB catheters placed at LRMC reported significantly less pain right now (P = 0.031) and better pain relief (P = 0.029) than soldiers without CPNBs. CONCLUSIONS Our findings underscore the value of early aggressive pain management after major combat injuries. Increased pain was associated with increased anxiety, distress, and worry during transport, suggesting the need for psychological management along with analgesia. Regional anesthesia techniques while at LRMC contributed to better pain outcomes.

Anaesthetic Agents for Advanced Regional Anaesthesia A North American Perspective

Interest in the use of regional anaesthesia, particularly peripheral nerve blocks (PNBs) and continuous PNBs, has increased in recent years. Accompanying this resurgence in interest has been the development of new local anaesthetics and additives designed to enhance block duration and quality. This manuscript provides a literature-based review on accepted uses of local anaesthetics and adjuncts for a variety of regional anaesthesia techniques. A brief review of local anaesthetic pharmacodynamics describes the action of these drugs in preventing nerve depolarisation, thus blocking nerve impulses. Toxic adverse effects of local anaesthetics, specifically CNS and cardiac manifestations of excessive local anaesthetic blood concentrations and the direct neurotoxic properties of local anaesthetics, are discussed generally and specifically for many commonly used local anaesthetics. Clinically useful ester and amide local anaesthetics are evaluated individually in terms of their physical properties and toxic potential. How these properties impact on the clinical uses of each local anaesthetic is explored. Particular emphasis is placed on the long-acting local anaesthetic toxic potential of racemic bupivacaine compared with levobupivacaine and ropivacaine, which are both levorotatory stereoisomers. Guidelines for using ropivacaine and mepivacaine, based on the authors’ experience using advanced regional anaesthesia in a busy practice, is provided. Finally, epinephrine (adrenaline), clonidine and other local anaesthetic additives and their rationale for use is covered along with other future possibilities.

Preliminary Validation of the Defense and Veterans Pain Rating Scale (DVPRS) in a Military Population

BACKGROUND The Army Surgeon General released the Pain Management Task Force final report in May 2010. Among military providers, concerns were raised that the standard numeric rating scale (NRS) for pain was inconsistently administered and of questionable clinical value. In response, the Defense and Veterans Pain Rating Scale (DVPRS) was developed. METHODS The instrument design integrates pain rating scale features to improve interpretability of incremental pain intensity levels, and to improve communication and documentation across all transitions of care. A convenience sample of 350 inpatient and outpatient active duty or retired military service members participated in the study at Walter Reed Army Medical Center. Participants completed the five-item DVPRS-one pain intensity NRS with and without word descriptors presented in random order and four supplemental items measuring general activity, sleep, mood, and level of stress and the Brief Pain Inventory seven interference items. Using systematic sampling, a random sample was selected for a word descriptor validation procedure matching word phases to corresponding pain intensity on the NRS. RESULTS Parallel forms reliability and concurrent validity testing demonstrated a robust correlation. When the DVPRS was presented with the word descriptors first, the correlation between the two ratings was slightly higher, r = 0.929 (N = 171; P < 0.001), than ordering first without the descriptors, r = 0.882 (N = 177; P < 0.001). Intraclass correlation coefficient was 0.943 showing excellent alignment of word descriptors by respondents (N = 42), matching them correctly with pain level. CONCLUSIONS The DVPRS tool demonstrated acceptable psychometric properties in a military population.

Small-Dose Intrathecal Lidocaine Versus Ropivacaine for Anorectal Surgery in an Ambulatory Setting

Spinal anesthesia with the local anesthetic lidocaine has come under scrutiny because it is associated with transient neurologic symptoms (TNS). We designed this study to prospectively compare the efficacy of ropivacaine as an alternative to lidocaine in patients undergoing elective outpatient anorectal procedures. Seventy-two patients were randomized to receive either hyperbaric lidocaine 25 mg with fentanyl 20 &mgr;g (n = 37) or hyperbaric ropivacaine 4 mg with fentanyl 20 &mgr;g (n = 35). Patients were examined for motor block, sensory block, and block duration. Patients were contacted at 24, 48, 72, and 168 h and questioned about their perceptions of pain after the spinal with specific questions designed to diagnose TNS. There were no patients with TNS in either group. There was no significant difference between the lidocaine and ropivacaine groups in any of the outcomes studied. In conclusion, intrathecal hyperbaric small-dose ropivacaine with fentanyl is an acceptable anesthetic for anorectal surgery.

Double-blinded, placebo-controlled, prospective randomized trial evaluating the efficacy of paravertebral block with and without continuous paravertebral block analgesia in outpatient breast cancer surgery.

BACKGROUND Paravertebral block (PVB) is an effective alternative to general anesthesia for breast cancer surgery. Continuous paravertebral block (CPVB) anesthesia may extend postoperative analgesia at home and improve quality of early postoperative recovery of breast cancer patients. PURPOSE This double-blinded randomized trial was conducted to compare degree of pain, nausea, mood, level of symptom distress, and time to return to normal daily activity between PVB and PVB + CPVB in patients undergoing outpatient breast cancer surgery. PATIENTS AND METHODS Between July 2003 and April 2008 we randomly assigned 94 (73 evaluable) patients in a 1:1:1 ratio with early breast cancer to single injection PVB followed by CPVB infusion of 0.1% or 0.2% ropivacaine vs placebo (saline) for 48 hours postoperatively for unilateral breast cancer surgery without reconstruction. The primary study endpoint was the degree of pain, nausea, mood state, level of symptom distress, and recovery time. RESULTS Of the 468 patients assessed for eligibility, 94 consented and 21 with incomplete data or follow-up were excluded, leaving 73 subjects for analysis. There was no clinically significant difference in degree of postoperative pain, nausea, mood state, level of symptom distress, or return to normal activity among the three study groups. CONCLUSION The current study does not support the routine use of continuous paravertebral catheter anesthesia in patients undergoing operative treatment for breast cancer.