Acute and Chronic Pain on the Battlefield: Lessons Learned from Point of Injury to the United States.

Historically, war tends to accelerate innovation within military medicine. In this article, the authors argue this truism has recurred in the case of acute and chronic pain management for combatants in the global war on terrorism (GWOT). Advances in regional anesthesia techniques and multimodal acute pain care are highlighted in light of the typical weapons, injuries, and comorbid conditions of the modern combat era. Reported success of providing chronic pain care in the war theater during GWOT is discussed in the context of operational requirements for current and future wars. A description is provided of the Pain Management Task Force (PMTF) and Pain Campaign Plan which was initiated during GWOT. The PMTF effort enhanced pain education and clinical pain care through leadership and organizational changes, which created broader access to pain treatments for patients and more standardized treatment capabilities across the enterprise.

Research design considerations for single-dose analgesic clinical trials in acute pain: IMMPACT recommendations.

This article summarizes the results of a meeting convened by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) on key considerations and best practices governing the design of acute pain clinical trials. We discuss the role of early phase clinical trials, including pharmacokinetic-pharmacodynamic (PK-PD) trials, and the value of including both placebo and active standards of comparison in acute pain trials. This article focuses on single-dose and short-duration trials with emphasis on the perioperative and study design factors that influence assay sensitivity. Recommendations are presented on assessment measures, study designs, and operational factors. Although most of the methodological advances have come from studies of postoperative pain after dental impaction, bunionectomy, and other surgeries, the design considerations discussed are applicable to many other acute pain studies conducted in different settings.

Advanced regional anesthesia morbidity and mortality grading system: regional anesthesia outcomes reporting (ROAR).

OBJECTIVE: A regional anesthesia complication grading system (regional anesthesia outcomes reporting [ROAR]) was developed and applied to 1,213 consecutive patients over a 14-month period. The goal of the project was the creation of a system to standardize complication reporting in the regional anesthesia literature. DESIGN: Patient demographics, status as a war casualty, regional block procedure-specific details, and complication grade were entered into an Internet-based, encrypted Department of Defense database. Regional anesthesia complications were later graded and subcategorized depending on what phase of the block the procedural adverse event took place. RESULTS: One thousand ninety-eight (90.5%) patients had neither regional anesthesia associated technical difficulties or more severe complications. Of a total of 147 cases with adverse events among 115 patients (1.3 per patient), the majority (63.3%, 93/147) were low-grade complications resulting in no significant morbidity. The most common complications resulting in patient morbidity were failed block requiring catheter removal and/or supplemental block (35.4%, 17/48). High grade complications represented only 4.1% (6/147) of all peri-procedural morbidity. These complications included pneumothorax requiring tube thoracostomy, transient laryngeal nerve dysfunction, and cancellation of planned operation after peripheral nerve block or catheter placement. CONCLUSIONS: The value of the ROAR system is that it identifies important issues in risk management in regional anesthesia, thereby providing opportunities for further investigation and clinical practice refinement. Furthermore, it provides for a common language when reporting outcomes in the regional anesthesia literature. Use of the ROAR system will provide consistency in outcomes reporting and facilitate comparisons between methods and procedures.

Quality of reporting of regional anesthesia outcomes in the literature.

OBJECTIVE: Consistent and reliable standards for reporting of regional anesthetic adverse events are lacking. The quality of reporting of regional anesthetic morbidity has not been assessed critically. AIM: To evaluate quality of regional anesthesia outcomes reporting. Methods. Published retrospective or prospective observational cohort or randomized controlled trials in peer-reviewed journals were reviewed, and judged according to seven criteria related to quality of reporting of regional anesthesia complications: method of accrual, duration of data collection, definition of complication, morbidity and mortality rates, grade of complication severity, exclusion criteria, and study follow up. Differences in reporting outcomes according to study design, sample size and time period were compared. RESULTS: Ninety-one articles published from 1996-2006 involving 8,833 patients were analyzed. The majority of studies (75%) met < or =4 reporting criteria. Recently published, prospective studies with >200 patients were associated with significantly higher-quality reporting (P < 0.05). Fewer than 50% of studies reported at least one recognized, accepted complication with defined criteria or indicated duration of follow up. Reporting compliance was worse (29%) for reporting of actual morbidity rates, and complications leading to death. Complication severity grading related to regional anesthesia was reported in 2% of studies. CONCLUSION: Consistent and comparative regional anesthesia outcome data are lacking in peer-reviewed journals. A graded regional anesthetic morbidity and mortality system according to the intensity of therapy required for the treatment of the defined complication is proposed, along with a structured format for the reporting of regional anesthesia complications according to defined reporting standards.

Utilidad de los anestésicos locales en anestesia regional / Local anesthetics for regional anesthesia: an update

La anestesia regional en el siglo XXI, específicamente el bloqueos nervioso periférico y el bloqueo continuo de nervios periféricos, siguen gozando de una popularidad sin precedentes. A pesar de este resurgimiento de la popularidad, la investigación de un anestésico local nuevo y de acción más prolongada e inyectable con mejor perfil de seguridad sigue siendo un objetivo distante y difícil de lograr. Se han creado pocos anestésicos locales nuevos para uso clínico desde comienzos de la década de 1970. Los esfuerzos por mejorar la eficacia, la duración y la seguridad de los anestésicos locales inyectables incluyen aditivos y la nueva tecnología de localización de la aguja. Cualquier explicación convincente de los anestésicos locales de uso frecuente utilizados en la anestesia regional debe incluir un resumen detallado de la toxicidad de los anestésicos locales que incluya prevención, detección y tratamiento. Se plantea un enfoque específico sobre la aparición reciente de intralipid como tratamiento de la cardiotoxicidad inducida por anestésicos locales. Esta revisión de los anestésicos locales examinará la farmacología básica, explorará las tendencias actuales en la práctica de la anestesia regional y describirá los adelantos recientes en el uso clínico de los anestésicos locales y sus aditivos.

Regional anesthesia in the 21st century, specifically peripheral nerve blocks (PNBs) and continuous peripheralnerve blocks (CPNBs), continues to enjoy unparalleled popularity. Despite this resurgence in popularity, thesearch for a new, longer-acting local anesthetic (LA) forinjection with an improved safety profile remains anelusive and distant goal. A paucity of new local anestheticshas been developed for clinical use since the early 1970’s.Efforts to improve the efficacy, duration, and safety ofinjected LAs include drug additives to LAs and new need lelocalization technology. Any cogent discussion of the common LAs used with regional anesthesia must includea thorough summary of LA toxicity to include prevention,detection, and treatment. A specific focus on the recentemergence of Intralipid as a treatment for local anestheticinducedcardiac toxicity will ensue. This LA review willexamine basic pharmacology, explore current trends in regional anesthesia practice, and describe recent developments in the clinical use of LA and additives.

Lumbar zygapophysial (facet) joint radiofrequency denervation success as a function of pain relief during diagnostic medial branch blocks: a multicenter analysis.

BACKGROUND CONTEXT: The publication of several recent studies showing minimal benefit for radiofrequency (RF) lumbar zygapophysial (l-z) joint denervation have led many investigators to reevaluate selection criteria. One controversial explanation for these findings is that the most commonly used cutoff value for selecting patients for l-z (facet) joint RF denervation, greater than 50% pain relief after diagnostic blocks, is too low and hence responsible for the high failure rate. PURPOSE: To compare l-z joint RF denervation success rates between the conventional greater than or equal to 50% pain relief threshold and the more stringently proposed greater than or equal to 80% cutoff for diagnostic medial branch blocks (MBB). STUDY DESIGN/SETTING: Multicenter, retrospective clinical data analysis. PATIENT SAMPLE: Two hundred and sixty-two patients with chronic low back pain who underwent l-z RF denervation at three pain clinics. OUTCOME MEASURES: Outcome measures were greater than 50% pain relief based on visual analog scale or numerical pain rating score after RF denervation persisting at least 6 months postprocedure, and global perceived effect (GPE), which considered pain relief, satisfaction and functional improvement. METHODS: Data were garnered at three centers on 262 patients who underwent l-z RF denervation after obtaining greater than or equal to 50% pain relief after diagnostic MBB. Subjects were separated into those who received partial (greater than or equal to 50% but less than 80%) and near-complete (greater than or equal to 80%) pain relief from the MBB. Outcomes between groups were compared with multivariate analysis after controlling for 14 demographic and clinical variables. RESULTS: One hundred and forty-five patients obtained greater than or equal to 50% but less than 80% pain relief after diagnostic MBB, and 117 patients obtained greater than or equal to 80% relief. In the greater than or equal to 50% group, success rates were 52% and 67% based on pain relief and GPE, respectively. Among patients who experienced greater than 80% relief from diagnostic blocks, 56% obtained greater than or equal to 50% relief from RF denervation and 66% had a positive GPE. CONCLUSIONS: Using more stringent pain relief criteria when selecting patients for l-z joint RF denervation is unlikely to improve success rates, and may lead to misdiagnosis and withholding a potentially valuable treatment from good candidates.

Responding to challenges in modern combat casualty care: innovative use of advanced regional anesthesia.

BACKGROUND: The war in Iraq has resulted in a high incidence of severe extremity injury requiring multiple surgical procedures and extensive rehabilitation. We describe the use of advanced regional anesthesia to meet this significant medical challenge. METHODS: From March 2003 to December 2004, 4,100 casualties have been evacuated to Walter Reed Army Medical Center (WRAMC). Of 1,400 inpatients, 750 have been battle-injured with 500 having extremity injuries. Of these, 287 (57%) received surgical care incorporating regional anesthesia including single-injection peripheral nerve blocks and continuous peripheral and epidural infusion catheters. Wounding, surgical, anesthetic, and outcomes data have been prospectively collected. RESULTS: Over 900 operations (mean 4+/-2/patient) were performed on 287 casualties prior to arrival at WRAMC, and 634 operations (mean 2+/-1/patient) were performed at WRAMC. Thirty-five percent of this cohort was amputees. In the study group, 646 advanced regional anesthesia procedures, including 361 continuous peripheral nerve blocks (CPNBs), were performed with a mean catheter infusion time of 9 days (1-34). Catheter-related complications occurred in 11.9% of casualties and were technical or minor in nature. Catheter-related infection rate was 1.9%. In 126 casualties with indwelling CPNB catheters, a significant decrease in pain score over 7 days was apparent (mean 3.7+/-0.2 to 2.2+/-0.2, P<0.001). CONCLUSION: Advanced regional anesthetic techniques allowed for safe perioperative surgical anesthesia and analgesia in the management of the modern combat casualty.