Modeling mechanisms of skull base injury for drivers in motor vehicle collisions.

OBJECTIVE: To develop biomechanical variable models for driver skull base injury mechanisms in motor vehicle collisions. STUDY DESIGN: Retrospective database review. METHODS: Biomechanical collision variables and safety restraint data were analyzed for Crash Injury Research and Engineering Network skull base trauma subjects enrolled during the recruitment period between 1996 and 2005. RESULTS: For drivers satisfying inclusion criteria (n = 26), injury resulted from contact with rigid vehicle structural elements in 82%, and occurred in 50% despite both seatbelt and air bags. Eight percent used neither seatbelts nor air bags. Seventy-two percent involved vector velocity changes greater than 30 mph. The relative morbidity of skull base injuries was also detailed. CONCLUSION: The majority of driver skull base injuries resulted from contact with rigid vehicle structural elements in high velocity crashes. Seatbelt and air bag use could not be definitively correlated with skull base injury. CLINICAL SIGNIFICANCE: Injury mechanism models can be developed that facilitate further investigations to determine impact and scope on a national scale.     

Medical management of chronic pancreatitis

慢性胰腺炎的临床表现包括疼痛、脂肪泻和糖尿病。在西方国家，慢性胰腺炎最常见的病因是酗酒。70％以上的病人在就诊时有疼痛的临床表现，而且，这些患者中又有75％以上会在几年之后出现疼痛减轻或完全消失。对于所有的慢性胰腺炎的病人来说，均应排除非胰源性疼痛和胆道梗阻、胰腺假性囊肿等胰腺局部并发症。应建议所有慢性胰腺炎病人戒烟、戒酒。阿片类镇痛剂仅应用于治疗疼痛严重的病人。尽管有报道认为胰酶替代治疗有助于止痛，但是，对于已经确诊的慢性胰腺炎病人来说，该疗法无效。激素类药物进行腹腔神经丛阻滞术可能有助于病人度过剧烈疼痛期。顽固性疼痛是进行胰液引流或胰腺切除的适应证。建议应用适量胰酶替代联合(或不联合)制酸剂治疗营养不良。慢性胰腺炎导致的糖尿病与原发性糖尿病的治疗原则相似。     

Red blood cell methotrexate and folate levels in children with acute lymphoblastic leukemia undergoing therapy: a Pediatric Oncology Group pilot study

Summary We enrolled children with acute lymphoblastic leukemia (ALL) in a Pediatric Oncology Group (POG) pilot study to monitor erythrocyte (RBC) methotrexate (MTX) and folate (F) levels before and during treatment. The mean value for RBCF at diagnosis was 0.86±0.46 nmol/ml RBC in the 214 patients who achieved remission and 1.21±0.74 nmol/ml RBC in the 10 patients who did not (P=0.020). Folate levels tended to increase during remission induction, but they dropped following an intensive consolidation with methotrexate to levels that were sustained throughout chemotherapy treatment. Methotrexate levels reached mean values of approximately 0.15 nmol/ml RBC at the end of an intensive methotrexate consolidation, then fell to levels that were sustained throughout maintenance therapy. There was a weak correlation between improved event-free survival and higher RBCMTX levels after consolidation, but no correlation was found between improved survival and the level of RBCMTX or RBCF during maintenance therapy. A larger study with more complete data is needed to determine whether RBCMTX or RBCF might be useful in predicting event-free survival in patients with ALL.This work was supported in part by grants from the National Cancer Institute and the National Institute of Health (CA-30969, CA-28476, CA29139, CA-159-89, and CA-33587)     

Difficult or Impossible Ventilation after Sufentanil-induced Anesthesia Is Caused Primarily by Vocal Cord Closure

Introduction: Opioid-induced rigidity often makes bag-mask ventilation difficult or impossible during induction of anesthesia. Difficult ventilation may result from chest wall rigidity, upper airway closure, or both. This study further defines the contribution of vocal cord closure to this phenomenon.

Methods: With institutional review board approval, 30 patients undergoing elective cardiac surgery participated in the study. Morphine (0.1 mg/kg) and scopolamine (6 micro gram/kg) given intramuscularly provided sedation along with intravenous midazolam as needed. Lidocaine 10% spray provided topical anesthesia of the oropharynx. A fiberoptic bronchoscope positioned in the airway photographed the glottis before induction of anesthesia. A second photograph was obtained after induction with 3 micro gram/kg sufentanil administered during a period of 2 min. A mechanical ventilator provided 10 ml/kg breaths at 10/min via mask and oral airway with jaw thrust. A side-stream spirometer captured objective pulmonary compliance data. Subjective airway compliance was scored. Pancuronium (0.1 mg/kg) provided muscle relaxation. One minute after the muscle relaxant was given, a third photograph was taken and compliance measurements and scores were repeated. Photographs were scored in a random, blinded manner by one investigator. Wilcoxon signed rank tests compared groups, with Bonferroni correction. Differences were considered significant at P <0.05.

Results: Twenty-eight of 30 patients exhibited decreased pulmonary compliance and closed vocal cords after opioid induction. Two patients with neither objective nor subjective changes in pulmonary compliance had open vocal cords after opioid administration. Both subjective and objective compliances increased from severely compromised values after narcotic-induced anesthesia to normal values (P = 0.000002) after patients received a relaxant. Photo scores document open cords before induction, progressing to closed cords after the opioid (P = 0.00002), and opening again after a relaxant was administered (P = 0.00005).     

Developing a VATS lobectomy programme--can VATS lobectomy be taught?

OBJECTIVE: Although VATS lobectomy has been demonstrated to be safe and effective, the technique is not widely practiced. This may, in part, reflect difficulty in acquiring appropriate skills. We have evaluated the effect of experience and training on surgical outcomes during the development and establishment of a VATS lobectomy programme. METHODS: Data were collected prospectively on 276 consecutive VATS lobectomies under the care of a single consultant as either the primary surgeon or supervising four trainees. The series was divided into cohorts of 46 patients. These comprised one trainee cohort and five sequential consultant cohorts. Statistical analysis utilised standard tests of significance. RESULTS: Increasing experience with the VATS lobectomy programme was associated with a significant reduction in operating time but intraoperative blood loss and postoperative stay were not influenced by increasing consultant surgical experience. Training was associated with a mean increase of 22 min operative time (p=0.0005) but no increase in intraoperative blood loss, morbidity, mortality or postoperative stay. The 46 trainee operative times were similar to the first 46 consultant cases. CONCLUSIONS: VATS lobectomy can be safely taught to trainee thoracic surgeons. However, in view of the limited number of centres undertaking VATS lobectomy, training should be coordinated at a national level to concentrate experience and improve uptake of this technique.