Biomedical subjects

Robert Benjamin

Publications and source records attributed to Robert Benjamin.

5 recordsLinked to original sources

PubMed2005

Multilevel en bloc spondylectomy and chest wall excision via a simultaneous anterior and posterior approach for Ewing sarcoma.

STUDY DESIGN: A case study of a patient with Ewing sarcoma of T8 and T9 with paravertebral and chest wall involvement, who underwent neoadjuvant chemotherapy and subsequent multilevel en bloc spondylectomy and chest wall excision using a simultaneous anterior and posterior approach. OBJECTIVE: To show the feasibility of treating Ewing sarcoma of the thoracic spine with paravertebral and chest wall extension by multiagent chemotherapy followed by a multilevel en bloc spondylectomy and chest wall excision using a simultaneous anterior and posterior approach. SUMMARY OF BACKGROUND DATA: Ewing sarcoma is a primary malignant bone tumor that occasionally involves the spinal column. Most patients with Ewing sarcoma of the spine are treated with systemic chemotherapy followed by definitive local control. Radiation therapy is the usual mode of local control in these patients because the spinal column has historically been considered a surgically inaccessible site where wide surgical margins are difficult to obtain. However, en bloc spondylectomy techniques have been described that can probably further decrease the risk of local recurrence, thereby minimizing or even eliminating the need for radiation therapy. To our knowledge, a combined en bloc spondylectomy and chest wall excision in a patient with Ewing sarcoma in the spine has not been previously reported. METHODS: Neoadjuvant chemotherapy consisting of vincristine, doxorubicin, and cyclophosphamide was administered. After completion of the chemotherapy, an en bloc spondylectomy of T8 and T9 with removal of the chest wall was achieved using a simultaneous anterior and posterior approach to the spine. A stackable carbon fiber cage filled with autograft and allograft bone was inserted between T7 and T10. The spine was stabilized with anterior and posterior instrumentation. The chest wall was reconstructed with contoured polymethylmethacrylate and polypropylene (Marlex, Textile Development Associates, Inc., Franklin Square, NY) mesh. RESULTS: The patient maintained normal neurologic function, and pain was lessened. The margins were free of tumor, and tumor necrosis was 100%. After surgery, radiotherapy was not administered. No local tumor recurrence or distant metastases were evident at the last follow-up. Balance in the coronal and sagittal planes was maintained. The patient has returned to work and resumed normal activities of daily living. CONCLUSIONS: Multilevel en bloc spondylectomy and chest wall excision performed using a simultaneous anterior and posterior approach is a safe and effective technique that may be used to achieve adequate margins in select patients with malignant tumors involving the thoracic spine and chest wall. This technique can eliminate the need for radiation therapy in patients with Ewing sarcoma and probably decreases the risk of local recurrence compared with radiation therapy alone.

Adult↗

PubMed2005

Can near-infrared spectroscopy identify the severity of shock in trauma patients?

BACKGROUND: Our recent experimental study showed that peripheral muscle tissue oxygen saturation (StO2), determined noninvasively by near-infrared spectroscopy (NIRS), was more reliable than systemic hemodynamics or invasive oxygenation variables as an index of traumatic shock. The purpose of this study was to establish the normal range of thenar muscle StO2 in humans and the relationship between shock state and StO2 in trauma patients. METHODS: This was a prospective, nonrandomized, observational, descriptive study in normal human volunteers (n = 707) and patients admitted to the resuscitation area of our Level I trauma center (n = 150). To establish a normal StO2 range, an NIRS probe was applied to the thenar eminence of volunteers (normals). Subsequently, in a group of trauma patients, an NIRS probe was applied to the thenar eminence and data were collected and stored for offline analysis. StO2 monitoring was performed continuously and noninvasively, and values were recorded at 2-minute intervals. Five moribund trauma patients were excluded. Members of our trauma faculty, blinded to StO2 values, classified each patient into one of four groups (no shock, mild shock, moderate shock, and severe shock) using conventional physiologic parameters. RESULTS: Mean +/- SD thenar StO2 values for each group were as follows: normals, 87 +/- 6% (n = 707); no shock, 83 +/- 10% (n = 85); mild shock, 83 +/- 10% (n = 19); moderate shock, 80 +/- 12% (n = 14); and severe shock, 45 +/- 26% (n = 14). The thenar StO2 values clearly discriminated the normals or no shock patients and the patients with severe shock (p < 0.05). CONCLUSION: Decreased thenar muscle tissue oxygen saturation reflects the presence of severe hypoperfusion and near-infrared spectroscopy may be a novel method for rapidly and noninvasively assessing changes in tissue dysoxia.

Adult↗

PubMed2004

Long-term silicone central venous catheters impregnated with minocycline and rifampin decrease rates of catheter-related bloodstream infection in cancer patients: a prospective randomized clinical trial.

PURPOSE: To evaluate the efficacy of long-term nontunneled silicone catheters impregnated with minocycline and rifampin (M-R) in reducing catheter-related bloodstream infections. PATIENTS AND METHODS: This prospective, randomized, double-blind clinical trial was conducted at M.D. Anderson Cancer Center, a tertiary care hospital in Houston, TX. All patients in the trial had a malignancy. RESULTS: Between September 1999 and May 2002, 356 assessable catheters were used: 182 M-R and 174 nonimpregnated. The patients' characteristics were comparable between the two study groups. The mean (+/- standard deviation) duration of catheterization with M-R catheters was comparable to that of nonimpregnated catheters (66.21 +/- 30.88 v 63.01 +/- 30.80 days). A total of 17 catheter-related bloodstream infections occurred during the course of the study. Three were associated with the use of M-R catheters and 14 were associated with the nonimpregnated catheters, with a rate of catheter-related bloodstream infection of 0.25 and 1.28/1,000 catheter-days, respectively (P = .003). Gram-positive cocci accounted for the majority of the organisms causing the infections. There were no allergic reactions associated with M-R catheters. CONCLUSION: Long-term nontunneled central venous catheters impregnated with minocycline and rifampin are efficacious and safe in reducing catheter-related bloodstream infections in cancer patients.

Anti-Bacterial Agents↗

PubMed2004

Outcomes of treatment pathways in outpatient treatment of low risk febrile neutropenic cancer patients.

BACKGROUND: We treated low-risk febrile neutropenic cancer patients utilizing two standard outpatient antibiotic pathways: oral ampicillin/clavulanate (500 mg) and ciprofloxacin (500 mg) or intravenous ceftazidime (2 g) and clindamycin (600 mg) every 8 h. The objectives were to determine the success of outpatient treatment of low-risk febrile neutropenia, to identify factors predicting outpatient failure, and to determine mortality related to the febrile episode. METHODS: Eligibility criteria included solid tumor diagnosis, stable vital signs, temperature > or =38.0 degrees C, absolute neutrophil count (ANC) of <1000/ml, patient compliance, no significant organ dysfunction, ability to tolerate oral medication and fluids for oral pathway, residence within 30 miles of the institution, 24-h caregiver, and telephone and transportation access. RESULTS: There were 257 febrile episodes in 191 patients meeting the criteria. Patients were treated during March 1998 through February 2000. Median age was 48 (range, 17-77) years, and 60% (n = 153) had an entry ANC of <100/ml; 205 (80%) febrile episodes successfully responded to outpatient treatment, and 52 (20%) were hospitalized. Logistic regression analysis showed the following were related to hospitalization: mucositis >grade 2 (p < 0.002); Zubrod performance status > or =2 (p = 0.029); ANC <100/ml (p = 0.039), and age > or =70 years (p = 0.048). CONCLUSIONS: Outpatient treatment of low-risk febrile neutropenic cancer patients utilizing standard treatment pathways is associated with minimal morbidity and mortality and should be considered an acceptable standard of care with appropriate infrastructure available to provide strict and careful follow-up while on treatment. Certain factors are associated with higher risk of hospitalization and should be further examined in eligible patients with low-risk febrile neutropenia.

Adolescent↗

PubMed2004

Secondary ultrasound examination increases the sensitivity of the FAST exam in blunt trauma.

INTRODUCTION: Approximately one third of stable patients with significant intra-abdominal injury do not have significant intraperitoneal blood evident on admission. We hypothesized that a delayed, repeat ultrasound study (Secondary Ultrasound--SUS) will reveal additional intra-abdominal injuries and hemoperitoneum. METHODS: We performed a prospective observational study of trauma patients at our Level I trauma center from April 2003 to December 2003. Patients underwent an initial ultrasound (US), followed by a SUS examination within 24 hours of admission. Patients not eligible for a SUS because of early discharge, operative intervention or death were excluded. All US and SUS exams were performed and evaluated by surgical/emergency medicine house staff or surgical attendings. RESULTS: Five hundred forty-seven patients had both an initial US and a SUS examination. The sensitivity of the initial US in this patient population was 31.1% and increased to 72.1% on SUS (p < 0.001) for intra-abdominal injury or intra-abdominal fluid. The specificity for the initial US was 99.8% and 99.8% for SUS. The negative predictive value was 92.0% for the initial US and increased to 96.6% for SUS (p = 0.002). The accuracy of the initial ultrasound was 92.1% and increased to 96.7% on the SUS (p < 0.002). No patient with a negative SUS after 4 hours developed clinically significant hemoperitoneum. CONCLUSION: A secondary ultrasound of the abdomen significantly increases the sensitivity of ultrasound to detect intra-abdominal injury.

Abdomen↗