C-Fiber Loss as a Possible Cause of Neuropathic Pain in Schwannomatosis.

Schwannomatosis is the third form of neurofibromatosis and characterized by the occurrence of multiple schwannomas. The most prominent symptom is chronic pain. We aimed to test whether pain in schwannomatosis might be caused by small-fiber neuropathy. Twenty patients with schwannomatosis underwent neurological examination and nerve conduction studies. Levels of pain perception as well as anxiety and depression were assessed by established questionnaires. Quantitative sensory testing (QST) and laser-evoked potentials (LEP) were performed on patients and controls. Whole-body magnetic resonance imaging (wbMRI) and magnetic resonance neurography (MRN) were performed to quantify tumors and fascicular nerve lesions; skin biopsies were performed to determine intra-epidermal nerve fiber density (IENFD). All patients suffered from chronic pain without further neurological deficits. The questionnaires indicated neuropathic symptoms with significant impact on quality of life. Peripheral nerve tumors were detected in all patients by wbMRI. MRN showed additional multiple fascicular nerve lesions in 16/18 patients. LEP showed significant faster latencies compared to normal controls. Finally, IENFD was significantly reduced in 13/14 patients. Our study therefore indicates the presence of small-fiber neuropathy, predominantly of unmyelinated C-fibers. Fascicular nerve lesions are characteristic disease features that are associated with faster LEP latencies and decreased IENFD. Together these methods may facilitate differential diagnosis of schwannomatosis.

Pediatric Lawnmower Injuries.

OBJECTIVE: The aim of this study was to evaluate demographics, characteristics, and mechanisms of injuries caused by lawnmowers in children. METHODS: Chart review from 1990 to 2010 at a level I pediatric trauma center identified patients younger than 18 years with lawnmower injuries. Demographics and characteristics of the injuries were analyzed by descriptive statistical analysis. RESULTS: The study identified 88 subjects, with 80% males and 42% of the subjects younger than 5 years. When the lawnmower type was specified, riding lawnmowers caused the majority of injuries (72%). The most common mechanism of injury was related to slipping under lawnmower/being run over (51%). The most common injuries were lacerations (36%), fractures (27%), and amputations (22%); lower extremities were injured more frequently than other body areas (62%). The majority of patients (76%) required hospitalization with a mean length of stay (LOS) of 9.7 days and a mean number of procedures of 4. Complications included 6 infections, 1 tissue necrosis, and 1 death from hemorrhagic shock. Riding-lawnmower injuries were associated with younger children (P < 0.0001). Riding lawnmowers and younger age were associated with longer hospital LOS (P = 0.01, 0.006) and increased number of procedures (P = 0.03, 0.003, respectively). CONCLUSIONS: Lawnmower injuries are still prevalent in children despite national safety recommendations. Injuries seen with riding lawnmowers were associated with younger age, higher number of procedures, longer LOS, and more severe injuries.

A randomized comparison of nitrous oxide plus hematoma block versus ketamine plus midazolam for emergency department forearm fracture reduction in children.

OBJECTIVES: Ketamine provides effective and relatively safe sedation analgesia for reduction of fractures in children in the emergency department. However, prolonged recovery and adverse effects suggest the opportunity to develop alternative strategies. We compared the efficacy and adverse effects of ketamine/midazolam to those of nitrous oxide/hematoma block for analgesia and anxiolysis during forearm fracture reduction in children. METHODS: Children 5 to 17 years of age were randomly assigned to receive intravenous ketamine (1 mg/kg)/midazolam (0.1 mg/kg; max: 2.5 mg) or 50% nitrous oxide/50% oxygen and a hematoma block (2.5 mg/kg of 1% buffered lidocaine). All of the children received oral oxycodone 0.2 mg/kg (max: 15 mg) at triage > or = 45 minutes before reduction. Videotapes were obtained before (baseline), during (procedure), and after (recovery) reduction and scored using the Procedure Behavioral Checklist by an observer blinded to study purpose. The primary outcome measure was the mean change in Procedure Behavioral Checklist score from baseline to procedure, with greater change indicating greater procedure distress. Other outcome measures of efficacy included recovery times and visual analog scale scores to assess patient distress, parent report of child distress, and orthopedic surgeon satisfaction with sedation. Adverse effects were assessed during the emergency visit and by telephone 1 day after reduction. Data were analyzed using repeated measures, that is, analysis of variance, chi2, and t tests. RESULTS: There were 102 children (mean age: 9.0 +/- 3.0 years) who were randomly assigned. There was no difference in age, race, gender, and baseline Procedure Behavioral Checklist scores between ketamine/midazolam (55 subjects) and nitrous oxide/hematoma block (47 subjects). Mean changes in Procedure Behavioral Checklist scores were very small for both groups. The mean change in Procedure Behavioral Checklist was less for nitrous oxide/hematoma block, and patients and parents reported less pain during fracture reduction with nitrous oxide/hematoma block. Recovery times were markedly shorter for nitrous oxide/hematoma block compared with ketamine/midazolam. Orthopedic surgeons were similarly satisfied with the 2 regimens. Of the ketamine/midazolam subjects, 11% had O2 saturations < 94%. Other adverse effects occurred in both groups, but more often in ketamine/midazolam both during the emergency visit and at 1-day follow-up. CONCLUSIONS: In children who had received oral oxycodone, both nitrous oxide/hematoma block and ketamine/midazolam resulted in minimal increases in distress during forearm fracture reduction at the doses studied. The nitrous oxide/hematoma block regimen had fewer adverse effects and significantly less recovery time.

Differentiation between septic arthritis and transient synovitis of the hip in children with clinical prediction algorithms.

BACKGROUND: Differentiation between septic arthritis and transient synovitis of the hip in children can be difficult. Kocher et al. recently developed a clinical prediction algorithm for septic arthritis based on four clinical variables: history of fever, non-weight-bearing, an erythrocyte sedimentation rate of >or=40 mm/hr, and a serum white blood-cell count of >12000/mm(3) (>12.0 x 10(9)/L). The purpose of this study was to apply this clinical algorithm retrospectively to determine its predictive value in our patient population. METHODS: A retrospective review was performed to identify all children who had undergone a hip arthrocentesis for the evaluation of an irritable hip at our institution between 1992 and 2000. One hundred and sixty-three patients with 165 involved hips satisfied the criteria for inclusion in the study and were classified as having true septic arthritis (twenty hips), presumed septic arthritis (twenty-seven hips), or transient synovitis (118 hips). RESULTS: Patients with septic arthritis (true and presumed; forty-seven hips) differed significantly (p < 0.05) from patients with transient synovitis (118 hips) with regard to the erythrocyte sedimentation rate, differential of serum white blood-cell count, total white blood-cell count and differential in the synovial fluid, gender, previous health-care visits, and history of fever. If the four independent multivariate predictors of septic arthritis proposed by Kocher et al. were present, the predicted probability of the patient having septic arthritis was 59% in our study, in contrast to the 99.6% predicted probability in the patient population described by Kocher et al. Statistical analyses demonstrated that the best model to describe our patient population was based on three variables: a history of fever, a serum total white blood-cell count of >12000/mm(3) (>12.0 x 10(9)/L), and a previous health-care visit. When all three variables were present, the predicted probability of the patient having septic arthritis was 71%. CONCLUSIONS: Although the use of a clinical prediction algorithm to differentiate between septic arthritis and transient synovitis may have improved the utility of existing technology and medical care to facilitate the diagnosis at the institution at which the algorithm originated, application of the algorithm proposed by Kocher et al. or of our three-variable model does not appear to be valid at other institutions.

Emergency department management of pain and anxiety related to orthopedic fracture care: a guide to analgesic techniques and procedural sedation in children.

Orthopedic fractures and joint dislocations are among the most painful pediatric emergencies. Safe and effective management of fracture-related pain and anxiety in the emergency department reduces patient distress during initial evaluation and often allows definitive management of the fracture. No consensus exists on which pharmacologic regimens for procedural sedation/analgesia are safest and most effective. For some children, control of fracture pain is the primary goal, whereas for others, relief from anxiety is an additionally important objective. Furthermore, strategies for the management of fracture pain may vary by fracture location and patient characteristics; thus, no single regimen is likely to provide the best means of analgesia and anxiolysis for all patients. Effective analgesia can be provided by local or regional anesthesia, such as hematoma, Bier, or nerve blocks. Alternatively, induction of deep sedation with analgesic agents such as ketamine or fentanyl, often combined with sedative-anxiolytic agents such as midazolam, may be used to manage distress associated with fracture reduction. A combination of local anesthesia with moderate sedation, for example nitrous oxide, is another attractive option.

Sedation for peritonsillar abscess drainage in the pediatric emergency department.

OBJECTIVE: To evaluate the use of intravenous (IV) sedation in children during peritonsillar abscess (PTA) incision and drainage in the emergency department (ED). DESIGN: Retrospective review of medical records of children with a diagnosis of PTA. SETTING: The ED of a large, urban, academic children's hospital. PATIENTS: Consecutive patients 18 years or younger presenting from April 1995 to November 1998. METHODS: Information was retrieved from a time-based sedation record that included age, sex, ASA classification, time since last liquid or solid, agent and dose, level of sedation (A=alert, V=response to voice, P=purposeful response to pain, U=unresponsive), vital signs, complications, recovery time, and disposition. RESULTS: Forty-two patients had incision and drainage performed with IV sedation in the ED. Mean age was 11.3 +/- 4.3 years (range 4-18 years); 57% were African-American, and 64% were female. Agents used included ketamine plus midazolam (K/M) (n = 36, 86%), morphine plus midazolam (n = 3, 7%), meperidine plus midazolam (n = 2, 5%), and nitrous oxide plus midazolam (n = 1, 2%). No cardiorespiratory complications, including laryngospasm, occurred. Vomiting occurred in 1 patient who received meperidine and midazolam. The deepest level of sedation reached included: 12% A, 64% V, and 24% P. No patient who had an abscess drained in the ED with IV sedation was admitted, and mean recovery time was 81.0 +/- 30.1 minutes. CONCLUSIONS: IV sedation in children for incision and drainage of PTA by skilled personnel in the ED may eliminate the need for admission and surgical drainage in the operating room. K/M was used most frequently, without adverse effect, and all patients were discharged from the ED. Because K/M may result in deep sedation, appropriate personnel and equipment must be present.