Pediatric Thoracic Trauma Mortality in Iraq and Afghanistan Compared to the United States National Trauma Data Bank.

INTRODUCTION: The authors compared pediatric thoracic patients in the Joint Theatre Trauma Registry (JTTR) to those in the National Trauma Data Bank (NTDB) to assess differences in patient mortality rates and mortality risk accounting for age, injury patterns, and injury severity. MATERIALS AND METHODS: Patients less than 19 years of age with thoracic trauma were identified in both the JTTR and NTDB. Multiple logistic regression, χ2, Student's t-test, or Mann-Whitney U test were used as indicated to compare the two groups. RESULTS: Pediatric thoracic trauma patients seen in Iraq and Afghanistan (n = 955) had a significantly higher mortality rate (15.1 vs. 6.0%, P <.01) than those in the NTDB (n = 9085). After controlling for covariates between the JTTR and the NTDB, there was no difference in mortality (odds ratio for mortality for U.S. patients was 0.74, 95% CI 0.52-1.06, P = .10). The patients seen in Iraq or Afghanistan were significantly younger (8 years old, interquartile ratio (IQR) 2-13 vs. 15, IQR 10-17, P <.01) had greater severity of injuries (injury severity score 17, IQR 12-26 vs. 12, IQR 8-22, P <.01), had significantly more head injuries (29 vs. 14%, P <.01), and over half were exposed to a blast. DISCUSSION: Pediatric patients with thoracic trauma in Iraq and Afghanistan in the JTTR had similar mortality rates compared to the civilian population in the NTDB after accounting for confounding covariates. These findings indicate that deployed military medical professionals are providing comparable quality of care in extremely challenging circumstances. This information has important implications for military preparedness, medical training, and casualty care.

Pediatric Thoracic Trauma in Iraq and Afghanistan.

Introduction: The objective of this study is to review available data on pediatric thoracic trauma seen at U.S. military treatment facilities in Iraq and Afghanistan and describe the scope of injuries, patterns seen, and associated mortality. The results were compared with adults injured in Iraq and Afghanistan and other reports of pediatric thoracic trauma in the literature. Materials and Methods: The investigators received approval from the Uniformed Services University of the Health Sciences' institutional review board before the study. The Joint Theatre Trauma Registry was queried for all patients with an ICD-9 code for thoracic trauma. Two-tailed Student's t-test, Mann-Whitney rank sum, χ2, ANOVA, or multiple logistic regression was used as indicated. Results: There were 955 patients under the age of 18 yr, just over 12% of all thoracic trauma. Penetrating injuries were common (73.6%), including gunshot wounds. The most common pediatric diagnoses were contusions (45%), pneumothorax (40%), and rib and/or sternal fractures (18%). The overall mortality for children was 15.2% compared with 13.8% and 9% for civilian adults and Coalition members with thoracic trauma, respectively. Mortality was inversely related to age among pediatric patients. Children under 2 yr of age had the highest mortality (25.1%). Patients under 12 yr of age were more likely to die than those between 12 and 18 (OR 2.02, 95% CI 1.27-3.22) yr. Thoracic vascular injuries and cardiac injuries resulted in the highest mortality among pediatric patients. The presence of a hemothorax was independently associated with an increased risk for mortality (OR 1.78, 95% CI 1.06-2.99) as was a concomitant head injury (OR 2.17, 95% CI 1.33-3.54). There was a 2.7% incidence of burns among pediatric patients with a high associated mortality (46.2%). Nearly one-half of all the children identified required a transfusion (47%). Conclusion: Penetrating injuries predominated and these children commonly required a transfusion. Mortality was inversely related to age. Children with a hemothorax or a concomitant head injury had significant increases in mortality. Children with thoracic injury as the result of a burn suffered the highest mortality.

The effect of lipid emulsion infusion on postmortem ropivacaine concentrations in swine: endeavoring to comprehend a soldier's death.

BACKGROUND: Lipid emulsion (20%) is advocated as a rescue drug for local anesthetic toxicity. No study has measured the impact of lipid emulsion therapy on postmortem local anesthetic serum levels. METHODS: We anesthetized Yorkshire swine (n = 11) and standard monitors were placed. The swine received 1.5 mg/kg/min IV ropivacaine until death (asystole). Blood samples were drawn before infusion (baseline) and at 5-minute intervals during the infusion for measurement of blood gases and free, bound, and total serum ropivacaine concentrations via high-performance liquid chromatography. Five swine received ropivacaine only, and 6 swine received ropivacaine plus a single bolus dose of 20% lipid emulsion (1 mg/kg) when the mean arterial blood pressure reached 50 mm Hg. Ropivacaine infusions were terminated at asystole and no resuscitation was initiated. Total ropivacaine dose and time to death were recorded. The swine were cooled (mean temperature, 25.5°C ± 0.8°C at 6 hours postmortem) to reflect morgue conditions. Serum samples were drawn at asystole, 1, 3, and 6 hours postmortem for analysis. Additionally, a craniotomy and laparotomy were performed at those times to remove 1.5 to 3 g each of brain, lung, liver, kidney, and muscle for analysis. RESULTS: Analysis of the postmortem serum ropivacaine concentrations in the control and the lipid-treated animals indicated that both the total (bound and not bound to proteins) and free (not bound to proteins) ropivacaine concentrations were significantly higher in the lipid-treated animals (P = 0.0094 and P = 0.0063, respectively). Furthermore, time had a significant effect on increasing the postmortem free ropivacaine concentrations (P = 0.0095). The lipid group had a statistically significant earlier onset of death (asystole) compared with the control group (P = 0.0274). Tissue analysis indicated that the ropivacaine concentration significantly decreased postmortem in the lung, kidney, and brain tissues of the lipid-treated animals (P = 0.0168, P = 0.0073, and P = 0.0018, respectively). Tissue drug concentrations in the control animals remained unchanged after death. CONCLUSIONS: Our data show that postmortem blood samples in swine that experience local anesthetic cardiovascular collapse and are treated with lipid emulsions will result in measurements that cannot be directly extrapolated to premortem drug concentrations.

Multicenter, randomized, comparative cost-effectiveness study comparing 0, 1, and 2 diagnostic medial branch (facet joint nerve) block treatment paradigms before lumbar facet radiofrequency denervation.

BACKGROUND: Among patients presenting with axial low back pain, facet arthropathy accounts for approximately 10-15% of cases. Facet interventions are the second most frequently performed procedures in pain clinics across the United States. Currently, there are no uniformly accepted criteria regarding how best to select patients for radiofrequency denervation. METHODS: A randomized, multicenter study was performed in 151 subjects with suspected lumbar facetogenic pain comparing three treatment paradigms. Group 0 received radiofrequency denervation based solely on clinical findings; group 1 underwent denervation contingent on a positive response to a single diagnostic block; and group 2 proceeded to denervation only if they obtained a positive response to comparative blocks done with lidocaine and bupivacaine. A positive outcome was predesignated as > or =50% pain relief coupled with a positive global perceived effect persisting for 3 months. RESULTS: In group 0, 17 patients (33%) obtained a successful outcome at 3 months versus eight patients (16%) in group 1 and 11 (22%) patients in group 2. Denervation success rates in groups 0, 1, and 2 were 33, 39, and 64%, respectively. Pain scores and functional capacity were significantly lower at 3 months but not at 1 month in group 2 subjects who proceeded to denervation compared with patients in groups 0 and 1. The costs per successful treatment in groups 0, 1, and 2 were $6,286, $17,142, and $15,241, respectively. CONCLUSIONS: Using current reimbursement scales, these findings suggest that proceeding to radiofrequency denervation without a diagnostic block is the most cost-effective treatment paradigm.

Back pain during war: an analysis of factors affecting outcome.

BACKGROUND: Back pain is the leading cause of disability in the world, but it is even more common in soldiers deployed for combat operations. Aside from battle injuries and psychiatric conditions, spine pain and other musculoskeletal conditions are associated with the lowest return-to-unit rate among service members medically evacuated out of Operations Iraqi and Enduring Freedom. METHODS: Demographic, military-specific, and outcome data were prospectively collected over a 2-week period at the Deployed Warrior Medical Management Center in Germany on 1410 consecutive soldiers medically evacuated out of theaters of combat operations for a primary diagnosis pertaining to back pain between 2004 and 2007. The 2-week period represents the maximal allowable time an evacuated soldier can spend in treatment before disposition (ie, return to theater or evacuate to United States) is rendered. Electronic medical records were then reviewed to examine the effect a host of demographic and clinical variables had on the categorical outcome measure, return to unit. RESULTS: The overall return-to-unit rate was 13%. Factors associated with a positive outcome included female sex, deployment to Afghanistan, being an officer, and a history of back pain. Trends toward not returning to duty were found for navy and marine service members, coexisting psychiatric morbidity, and not being seen in a pain clinic. CONCLUSIONS: The likelihood of a service member medically evacuated out of theater with back pain returning to duty is low irrespective of any intervention(s) or characteristic(s). More research is needed to determine whether concomitant treatment of coexisting psychological factors and early treatment "in theater" can reduce attrition rates.

Pediatric wartime admissions to US military combat support hospitals in Afghanistan and Iraq: learning from the first 2,000 admissions.

BACKGROUND: Humanitarian and civilian emergency care accounts for up to one-third of US military combat support hospital (CSH) admissions. Almost half of these admissions are children. The purpose of this study is to describe the features of pediatric wartime admissions to deployed CSHs in Iraq and Afghanistan. METHODS: A retrospective database review was conducted using the Patient Administration Systems and Biostatistics Activity. Details of 2,060 pediatric admissions to deployed CSHs were analyzed. RESULTS: Nontraumatic diagnoses were responsible for 25% of all pediatric admissions. Penetrating injuries (76.3%) dominate the trauma admissions. The primary mechanisms of injury were gunshot wound (39%) followed by explosive injuries (32%). Categorizing the injuries by location revealed 38.3% extremity wounds, 23.6% torso injuries, 23.5% head, face, and neck injuries, and 13.3% burns. More than half of the children required two or more invasive or surgical procedures, 19.8% needed a transfusion, and 5.6% required mechanical ventilation. The mortality rate was 6.9%. The primary cause of death involved head trauma (29.5%) and burns (27.3%), followed by infectious diagnoses (7.2%). The case fatality rate for head injury and burn patients was 20.1% and 15.9%, respectively, in contrast to the fatality rate for all other diagnoses at 3.8% (p < 0.01). Excluding emergency department deaths, mortality rates for Afghanistan (6.2%) and Iraq (3.9%) significantly differ (p < 0.02). CONCLUSION: Pediatric patients account for approximately 10% of all CSH admissions in Afghanistan and Iraq. Burns and penetrating head injury account for the majority of pediatric mortality at the CSH.

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.

Awake thyroidectomy under local anesthesia and dexmedetomidine infusion.

UNLABELLED: Dexmedetomidine (DEX) is an alpha-2 receptor agonist with sedative and analgesic properties. It has been reported to preserve the patient's ability to cooperate and provide opioid sparing properties. Patients with obstructive sleep apnea (OSA) have demonstrated an increased risk for oxygen desaturation following general anesthesia. We report a case of a 64-year-old male, ASA IV with severe chronic obstructive pulmonary disease, OSA, unilateral vocal cord dysfunction, gastro-esophageal reflux disease, and congestive heart failure undergoing an awake thyroidectomy under local anesthesia and a DEX infusion. The patient was given a loading dose of DEX of 1 mcg/kg and an infusion ranging from 0.2 to 1.0 g/kg/hr. He received a total of 250 mcg of fentanyl and 7.5 mg of ketorolac throughout the case. RESULTS: The patient tolerated the procedure well. He was able to cooperate with simple commands. His vital signs remained stable. He reported a pain score of 2 out of 10 in the recovery unit. CONCLUSIONS: This case demonstrates the successful use of a DEX infusion along with local anesthesia administered by the surgeon for an awake thyroidectomy.

The effect of opioid dose and treatment duration on the perception of a painful standardized clinical stimulus.

BACKGROUND AND OBJECTIVES: The concept of opioid-induced hyperalgesia has recently gained prominence as a contributing factor for opioid tolerance and long-term treatment failure. But whereas the preclinical data for this phenomenon are strong, the mixed clinical data derive primarily from experimental pain models conducted in volunteers and heroin addicts, and nonstandardized clinical stimuli, e.g., surgery. The primary objective of this study is to delineate the effect of opioid dose and treatment duration on pain intensity and unpleasantness ratings following a standardized clinical pain stimulus. METHODS: Three hundred and fifty-five patients, on a steady regimen of analgesic medications and scheduled for an interventional procedure, received a standardized subcutaneous injection of lidocaine prior to a full dose of local anesthetic. Before and immediately following the injection, subjects were asked to rate pain and unpleasantness intensity on a 0 to 10 numerical rating scale. Subjects were stratified into 6 groups based on opioid dosage. A control group of 27 volunteers who had no pain and were taking no analgesics were also injected. RESULTS: Both opioid dose and duration of treatment directly correlated with pain intensity and unpleasantness scores. Baseline pain intensity was also positively associated with both outcome variables. Gender was found to be associated with pain intensity and unpleasantness, with females scoring higher in both categories than males. Compared with patients not receiving opioid treatment, patients receiving opioid therapy were more likely to rate the standardized pain stimulus as being more unpleasant than painful. CONCLUSIONS: The results of this study bolster preclinical and experimental pain models demonstrating enhanced pain perception in subjects receiving opioid therapy. This simple clinical model may provide a useful tool in examining opioid-induced hyperalgesia.

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.

Clinical utility of the bispectral index score when compared to the University of Michigan Sedation Scale in assessing the depth of outpatient pediatric sedation.

This single blinded observational study compared the bispectral index (BIS) monitor with a validated pediatric sedation scale, the University of Michigan Sedation Scale (UMSS), to evaluate whether the BIS score can be used to judge the depth of sedation in pediatric outpatients. Thirty-eight children, with a mean age of 5.8 years, undergoing routine sedation for both noninvasive and gastrointestinal procedures, had simultaneous BIS and UMSS scores recorded. Sedation categories were defined as light, moderate, and deep for both UMSS and BIS. There was a moderate correlation between BIS and the UMSS, Spearman's r < -0.499. The correlation was poor for children receiving chloral hydrate, r < -0.213. The BIS score was not predictive of any specific UMSS score. The UMSS and BIS categories of sedation matched only 36% of the time. BIS underestimated the clinical level of sedation.

Intraoperative management: peripheral vascular surgery.

Lower extremity atherosclerotic disease affects nearly 10 million people in the United States. Recent advances in diagnostic imaging and interventional techniques help many patients avoid more invasive surgical procedures. Those reaching the operating room, however,represent a distilled subset of patients who are prone to significant comorbidities. We outline current treatment strategies and discuss anesthetic concerns and techniques for these complex patients.

Sleep deprivation for pediatric sedated procedures: not worth the effort.

OBJECTIVE: Sleep deprivation is commonly used to enhance the effectiveness of pediatric sedation and to decrease sedation failures. We reviewed our sedation database to evaluate the efficacy of sleep deprivation. METHODS: The entire pediatric sedation unit database (n = 5640) was reviewed retrospectively. Patients without complete data sets were excluded. The remaining patients were separated into 2 groups: 3272 patients who underwent noninvasive procedures and 1210 who underwent invasive procedures. A subgroup of noninvasive procedure patients <2 years old (n = 1398) was also analyzed. The sedation failure rate (%) and nursing care hours for both sleep-deprived and non-sleep-deprived patients were analyzed. RESULTS: In the noninvasive procedure group, the sedation failure rate was 5.7% for the sleep-deprived patients and 5.6% for the non-sleep-deprived patients, whereas the sedation failure rate for children <2 years old was 4.2% for sleep-deprived patients and 4.7% for non-sleep-deprived patients. The sedation failure rate in the invasive procedure group was 7.5% for sleep-deprived patients and 7.2% for non-sleep-deprived patients. Nursing care hours in the noninvasive procedure group were significantly longer for the sleep-deprived patients (4.5 +/- 1.6 hours) versus the non-sleep-deprived patients (3.8 +/- 1.6 hours). This finding was true also for the subgroup of children <2 years old (sleep-deprived patients: 4.2 +/- 1.4 hours; non-sleep-deprived patients: 3.5 +/- 1.4 hours). No difference was noted in nursing care hours for the invasive procedure group. CONCLUSIONS: Sleep deprivation had no effect in reducing the pediatric sedation failure rate. The patients having noninvasive procedures who were sleep deprived required significantly more nursing care hours than their non-sleep-deprived counterparts. Routine use of sleep deprivation for pediatric sedation should be critically reevaluated.

Using high-fidelity patient simulation and an advanced distance education network to teach pharmacology to second-year medical students.

The feasibility and acceptance of an Advanced Distance Education Network (ADEN) in bringing the simulated operating room (OR) to second-year medical students learning the pharmacology of anesthetic drugs is reviewed. A MedSim-Eagle (Binghamton, NY) full-scale mannequin simulator was used. Using an ADEN, students were linked in real time to a simulated OR where the anesthesiologist instructor was using a MedSim-Eagle patient simulator to present for discussion the physiologic effects of volatile anesthetics on cardiac output (CO), heart rate (HR), mean arterial pressure (MAP), and systemic vascular resistance (SVR). The use of simulation to present basic science principles of isoflurane and halothane's effect on CO, HR, MAP, and SVR in a clinical setting via an ADEN is feasible. Student acceptance of this method of education is high, as measured by a post-exercise survey. Ninety-five percent of students felt this exercise was a valuable use of their time; 93% felt the ADEN-delivered clinical simulation presentation contributed to their understanding of the pharmacology of anesthesia. Eighty-three percent of students preferred this integrated clinically oriented review to a didactic review of the material, and 92% of students who had experienced previous small group hands-on session simulation felt the ADEN-delivered session was the same or better.

Using High-Fidelity Patient Simulation and an Advanced Distance Education Network to Teach Pharmacology to Second-Year Medical Students.

The feasibility and acceptance of an Advanced Distance Education Network (ADEN) in bringing the simulated operating room (OR) to second-year medical students learning the pharmacology of anesthetic drugs is reviewed. A MedSim-Eagle (Binghamton, NY) full-scale mannequin simulator was used. Using an ADEN, students were linked in real time to a simulated OR where the anesthesiologist instructor was using a MedSim-Eagle patient simulator to present for discussion the physiologic effects of volatile anesthetics on cardiac output (CO), heart rate (HR), mean arterial pressure (MAP), and systemic vascular resistance (SVR). The use of simulation to present basic science principles of isoflurane and halothane's effect on CO, HR, MAP, and SVR in a clinical setting via an ADEN is feasible. Student acceptance of this method of education is high, as measured by a post-exercise survey. Ninety-five percent of students felt this exercise was a valuable use of their time; 93% felt the ADEN-delivered clinical simulation presentation contributed to their understanding of the pharmacology of anesthesia. Eighty-three percent of students preferred this integrated clinically oriented review to a didactic review of the material, and 92% of students who had experienced previous small group hands-on session simulation felt the ADEN-delivered session was the same or better.

Regional anesthesia in austere environments.

Military anesthesiologists must master the complexities of modern anesthesia at home, like their civilian counterparts, and also be prepared to provide effective, safe anesthesia in the chaotic and austere environment of the modern battlefield. This article describes the Army Regional Anesthesia Initiative and Operational Anesthesia Rotation programs designed to facilitate this difficult goal.