Biomedical subjects

Helge Schoenfeld

Publications and source records attributed to Helge Schoenfeld.

7 recordsLinked to original sources

PubMed2007

Predictors of loss to follow-up in young patients with minor trauma after screening and written intervention for alcohol in an urban emergency department.

OBJECTIVE: In health promotion studies, young age, male gender, low education, and substance use have been found to be relevant predictors of loss to follow-up. The purpose of this study was to assess factors of loss to follow-up after screening and tailored brief advice for alcohol problems in an emergency department setting. METHOD: A randomized controlled intervention study was conducted and followed up at 12 months. At baseline (T0), 2,562 consecutive trauma patients (62.1% male) were screened for substance use (smoking, alcohol consumption, and illicit drug use) and for socioeconomic factors (income, relationship status, and education). Patients with five points or more in the Alcohol Use Disorders Identification Test randomly received tailored brief advice on alcohol and were followed up at 3 (T3), 6 (T6), 9 (T9), and 12 months (T12). RESULTS: At baseline, median age was 32 years (range: 18-89). There was a loss of 950 participants (37.1%) from T0 to T12. Loss to follow-up was strongly dependent on social factors. In participants with a high school diploma, only smoking was predictive of loss to follow-up (odds ratio [OR] = 1.81, 95% confidence interval [CI] = 1.43-2.29). In participants with no high school diploma, alcohol problems alone predicted loss to follow-up (medium level of alcohol problems, OR = 1.57, 95% CI = 1.09-2.27; high level of alcohol problems, OR = 1.62, 95% CI = 0.96-2.76; p = .017). Smoking (OR = 1.35, 95% CI = 0.97-1.89) and, for smokers, age 18-31 years (OR = 1.65, 95% CI = 0.98-2.78) showed a tendency toward an increased risk of loss to follow-up. CONCLUSIONS: After screening and a brief intervention in an emergency department, substance use and differences in education level predicted loss to follow-up. Patients with alcohol problems and no high school diploma are at increased risk of becoming lost to follow-up.

Adolescent↗

PubMed2006

Intervention at the level of the neuroendocrine-immune axis and postoperative pneumonia rate in long-term alcoholics.

RATIONALE: Postoperative pneumonia is three to four times more frequent in patients with alcohol use disorders followed by prolonged intensive care unit (ICU) stay. Long-term alcohol use leads to an altered perioperative hypothalamus-pituitary-adrenal (HPA) axis and immunity. OBJECTIVES: The aim of this study was to evaluate HPA intervention with low-dose ethanol, morphine, or ketoconazole on the neuroendocrine-immune axis and development of postoperative pneumonia in long-term alcoholic patients. METHODS: In this randomized, double-blind controlled study, 122 consecutive patients undergoing elective surgery for aerodigestive tract cancer were included. Long-term alcohol use was defined as consuming at least 60 g of ethanol daily and fulfilling the Diagnostic and Statistical Manual of Mental Disorders IV criteria for either alcohol abuse or dependence. Nonalcoholic patients were included but only as a descriptive control. Perioperative intervention with low-dose ethanol (0.5 g/kg body weight per day), morphine (15 mug/kg body weight per hour), ketoconazole (200 mg four times daily), and placebo was started on the morning before surgery and continued for 3 d after surgery. Blood samples to analyze the neuroendocrine-immune axis were obtained on the morning before intervention and on Days 1, 3, and 7 after surgery. MEASUREMENTS AND MAIN RESULTS: In long-term alcoholic patients, all interventions decreased postoperative hypercortisolism and prevented impairment of the cytotoxic T-lymphocyte type 1:type 2 ratio. All interventions decreased the pneumonia rate from 39% to a median of 5.7% and shortened intensive care unit stay by 9 d (median) compared with the placebo-treated long-term alcoholic patients. CONCLUSIONS: Intervention at the level of the HPA axis altered the immune response to surgical stress. This resulted in decreased postoperative pneumonia rates and shortened intensive care unit stay in long-term alcoholic patients.

APACHE↗

PubMed2006

Volume-reduced platelet concentrates.

Volume-reduced platelet concentrates (PCs) can be a useful option for transfusing a high number of platelets in the smallest possible plasma volume, especially in neonatal and other pediatric patients. In addition to decreasing the risk of circulatory overload, volume-reduced PCs contain less plasma, which may reduce the likelihood of adverse plasma-related transfusion reactions. Volume reduction can be achieved either during collection and processing of apheresis PCs (primary volume reduction) or, subsequently, by recentrifugation of stored PCs (secondary volume reduction). There is no standard method for preparing volume-reduced PCs. Although in vitro data suggest impaired platelet function with some methods of volume-reducing PCs, in vivo studies show acceptable hemostatic function, posttransfusion recovery, and platelet count increments for both primary and secondary volume-reduced PCs. This review presents an overview of recent studies on functional characteristics of different types of volume-reduced PCs.

Blood Platelets↗

PubMed2005

The functional integrity of platelets in volume-reduced platelet concentrates.

Premature and low-birth-weight infants usually require small-volume platelet transfusions to treat thrombocytopenia. Also, infants undergoing open-heart surgery with extracorporeal circulation and with compromised cardiac function are at risk for excessive intravascular volume. The small-volume platelet substitution can be achieved by dispensing an aliquot from the unit of a standard single-donor platelet concentrate (PC). Alternatively, there is an indication for volume reduction of PCs to maximize the number of platelets transfused in the smallest possible volume. We determined the spontaneous and induced activation of platelets before and after volume reduction in 20 consecutive single-donor-apheresis PCs. After a mean storage time of 2 days, the PCs were plasma-depleted by centrifugation. Spontaneous, adenosine diphosphate (ADP)-induced, and collagen-induced activation were determined by flow cytometry. Furthermore, ADP- and collagen-induced aggregation were measured. A total of 33.8% of platelets in standard PCs were activated spontaneously. Volume reduction of PCs led to a mild but significant increase of spontaneous activation of platelets (43.2%). Additionally, volume reduction resulted in an impaired ADP-induced aggregability of platelets, whereas collagen induction was unaffected. Transfusion of volume-reduced PCs is an effective alternative to use of standard PCs in patients at frequent risk for excessive intravascular volume, because equal volumes increase the platelet count twice as effectively.

Adenosine Diphosphate↗

PubMed2004

Platelet activity in washed platelet concentrates.

Life-threatening anaphylaxis or febrile nonhemolytic transfusion reactions after transfusion of platelet concentrates (PCs) is a serious clinical problem caused by the sensitizing of recipients to plasma components, such as immunoglobulin A, or by cytokines. There is a possible indication for washing of PCs in these thrombocytopenic patients. However, only platelets that show activation after physiological stimulation are useful. We determined the spontaneous and induced activation of platelets before and after washing. We investigated 11 consecutive single-donor-apheresis PCs. After production and leukocyte-depletion the PCs were washed in 15%, acid-citrate-dextrose-solution. The spontaneous and the adenosine diphosphate (ADP)-induced, as well as collagen-induced activation, were determined by flow cytometry. Additionally, ADP- and collagen-induced aggregation were measured. Unwashed platelets (16.1%) were activated spontaneously. The washing of PCs led to a threefold increase of spontaneous activation of platelets (47.4%). Because of increased spontaneous activation after washing we could demonstrate cytometrically a loss of induced activation of washed platelets. Furthermore, washing resulted in an impaired ADP-induced aggregability of platelets. These results have led us to reduce the frequency of washing of PCs in our institution, where the only current indication for washing of PCs is in patients with a history of severe nonhemolytic transfusion reactions.

Adenosine Diphosphate↗

PubMedDate not supplied

The role of contrast-enhanced spiral CT imaging versus chest X-rays in surgical therapeutic concepts and thoracic aortic injury: a 29-year Swiss retrospective analysis of aortic surgery.

BACKGROUND: Blunt chest trauma accounts for 90% of chest trauma in the civilian population in Europe and the United States and causes 20% of trauma-related deaths. Missed aortic injuries can rupture and lead to subsequent death of the patient. MATERIALS AND METHODS: This retrospective study compared two different imaging strategies, chest X-rays compared to additional contrast-enhanced spiral CT imaging, in patients suffering from blunt thoracic trauma. The study also questioned whether the additional information obtained from CT scans changed further surgical therapeutic concepts or the decision for immediate surgery. RESULTS: Between 1971 and 2001, 39 patients were detected with thoracic trauma and aortic lesions. Of the 28 patients who underwent initial CT scanning, 12 (31%) had an emergency thoracotomy (sternotomy) performed on them, which the other 16 did not require. In four (10%) of these 16 patients, the aorta was stabilised and a possible leak was covered with endovascular stenting. In another eight (21%) of them, the concomitant injuries were initially treated and, following regular check-ups, an elective repair of the aortic lesion was performed after a number of months. In four (10%) patients with intramural haematomas or minor leakage, no intervention was necessary. Eleven (28%) patients did not have a chest CT scan on admission and the diagnosis of a contained aortic rupture was missed. They were readmitted to the hospital between four months and 29 years after the initial accident with symptomatic posttraumatic pseudo-aneurysm of the thoracic aorta. CONCLUSIONS: We believe that helical CT evaluation of the mediastinum should be performed in all patients who undergo blunt thoracic trauma, irrespective of chest radiographic findings. Missed diagnoses can occur after angiography or ultrasound alone, and false-positive diagnoses can also be made. Following the current literature, we therefore recommend a primary routine chest CT scan in all patients with a history of motor vehicle accident (MVA) at a speed of more than 16 km/h (unrestrained) or 48 km/h (restrained). Furthermore, we recommend a CT scan even if the height fallen was as little as seven metres.

Adolescent↗

PubMedDate not supplied

Cryopreservation of platelets at the end of their conventional shelf life leads to severely impaired in vitro function.

Storage time for platelet concentrates (PCs) is limited to five days due to 'aging' of the platelets and an increasing risk of bacterial proliferation. Storage time can be prolonged by cryopreservation. We investigated in vitro function of six consecutive PCs at the end of their conventional shelf life followed by cryopreservation for 24 hours. Spontaneous, adenosine diphosphate (ADP)-induced and collagen-induced activation before and after cryopreservation were determined by flow cytometry. Additionally, ADP- and collagen-induced aggregation was measured. After cryopreservation two-thirds of the platelets were spontaneously activated, twice as many as before the procedure (p < 0.001). ADP-induced activation was significantly reduced (p = 0.014). Collagen-induced activation was unchanged. Aggregation stimulated by ADP and collagen was significantly reduced (p = 0.005 and p = 0.009, respectively). Our results show severely impaired in vitro function of platelets after storage at 22 degrees C for five days followed by cryopreservation. Cryopreservation of PCs after a storage time of five days cannot be recommended.

Adenosine Diphosphate↗