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Biomedical subjects

U Obertacke

Publications and source records attributed to U Obertacke.

At least 55 records · Page 3Linked to original sources
PubMed1997

Regulation of whole blood tumor necrosis factor production upon endotoxin stimulation after severe blunt trauma.

BACKGROUND: Trauma has been recognized to be accompanied by alterations of leukocyte functions such as cytokine release. The regulatory principles involved in these changes are still poorly defined. To further characterize leukocyte function after multiple trauma, endotoxin-stimulated tumor necrosis factor (TNF) production of trauma patients' whole blood and a possible regulatory mechanism were studied. METHODS: Endotoxin responsiveness in trauma patients (n = 18, Injury Severity Score = 24 +/- 7) was assayed ex vivo using a whole blood model. TNF release and TNFalpha mRNA levels were determined during a 14-day period. Furthermore, the influence of patients' sera on whole blood TNF production was evaluated. MAIN RESULTS: The capacity of trauma patients' whole blood to produce TNF was reduced for 2 to 6 days after trauma and was equally evident for both TNF release and TNFalpha mRNA levels. The reduction of TNF coincides with the appearance of an inhibitory activity for TNF production in trauma patients' sera. No correlation was found between the inhibitory activity and soluble TNF receptors, endotoxin-neutralizing molecules, inhibitory cytokines (interleukin 10 and transforming growth factor beta), or prostaglandins. CONCLUSIONS: Major trauma leads to the appearance of a circulating inhibitory activity for TNF synthesis that may potentially contribute to an anti-inflammatory response in patients with multiple trauma. The elucidation of its structural and functional properties may contribute to the understanding of the pathogenesis of severely injured patients.

Adolescent↗
PubMed1996

[Integrated concept for implementing clinical training in emergency medicine].

Since 1993 special lectures in emergency medicine are part of curriculum in the study of medicine at German universities. To intensify practical teaching in this field an integrative concept was followed in performing emergency training, the experiences of which are described in this paper. Seminars dealing with the most important subjects of preclinical care were combined with practical training blocks such as attendance at operations of the preclinical emergency physician service, resuscitation training using computerised resuscitation models (Mega Code), and an anatomical training course for endotracheal intubation, coniotomy, thoracic drainage, or central venous catheterisation on a corpse. If supported by physicians, senior students may supervise groups of 4 to 5 students during the Mega Code training in a tutorial system, thus allowing to intensify practical education. Since the integrative concept is based on cooperation of different medical specialties, the students expect one or two physicians to be chiefly responsible for the entire course. Additional dates during the semester interfere with the students' leisure activities and require individual practical activity. This means giving up a passively receptive attitude. However, as reflected by the results of the exams and questionnaires, response to this step of improvement in Emergency Medical Education has been very positive. Future efforts are directed at including more physicians as practical supervisors, scattering of training dates, an increase in compulsory practical participation such as one-day attendance at an intensive care unit, and intensified exams on practical issues. However, the improvement of the quality of teaching is imperative in the job planning of the medical profession.

Clinical Clerkship↗
PubMed1996

Nailing versus plating in thoracic trauma: an experimental study in sheep.

In this study, femoral intramedullary pressure, fat embolization, and pulmonary response were measured during reamed and unreamed nailing and plating of femoral fractures after blunt thoracic trauma. Intramedullary peak pressures of 425 mm Hg (mean 205 mm Hg) occurred in the reamed nail group (group I) during reaming with the 9-mm reamer, while in the unreamed nail group (group II) peak values were seen during nail insertion (330 mm Hg) with a mean of 203 mm Hg. Plating never led to a pressure rise over 67 mm Hg (mean 37 mm Hg). In reamed nailing, the most intense embolism was identified under ultrasound imaging with the large awl and with the 9.0-mm reamer (mean 2.2) and in the unreamed nail group during nail insertion (mean 2.8). Minimal echoes appeared during plating. The pulmonary arterial pressure did not vary significantly postoperatively between the three groups (p < 0.08). Our findings indicate that intramedullary fracture fixation causes a higher increase of intramedullary pressure and more fat and bone marrow embolization than extramedullary ones. Nevertheless, only minimal differences in the pulmonary hemodynamic response (pulmonary arterial pressure) were noted even in the presence of thoracic trauma.

Animals↗
PubMed1996

Effect of lung contusion on surfactant composition in multiple-trauma patients.

OBJECTIVE: The aim of this study was to investigate alterations of the surfactant system in multiple-trauma patients (MTP) with lung contusion and the influence of single- or multiple-organ dysfunction syndrome (OF/MOF) on the surfactant system. SETTING: University hospital, trauma-intensive care unit. DESIGN: Prospective, nonrandomized study. METHODS: MTP with an Injury Severity Score > 19 points have been recorded prospectively since 1992. Bronchoalveolar lavages were obtained daily either until day 14 or extubation. Three groups of MTP were compared: noL: MTP, no lung contusion (n = 14); LuCo-: MTP, lung contusion, no OF/MOF (n = 17); LuCo+: MTP, lung contusion, with OF/MOF (n = 10). Also, surfactant samples of 11 healthy volunteers (Con) were investigated and compared with MTP. All data were presented as mean +/- SEM. Statistical analysis were performed using programs of SPSS 6.0.1. (univariate ANOVA, Fisher's Exact Test, p < = 0.05). RESULTS: There were no differences in sex and age. Injury Severity Score was significantly impaired in group LuCo+ (44 +/- 4), compared with groups noL (31 +/- 3) and LuCo- (34 +/- 3). Group noL showed no statistical differences for lung function, total protein, and total phospholipid content of the bronchoalveolar lavage compared with group LuCo-. Furthermore, the relative content of phosphatidylcholine and phosphatidylglycerol in total phospholipids and surfactant-associated protein A were not significantly altered compared with group LuCo-. Lung function in group LuCo+ was significantly impaired and led to hypoxemia on the day of trauma. Total protein content and total phospholipids were significantly elevated in group LuCo+ compared with groups noL and LuCo- on the first day. Also, the relative content of phosphatidylcholine was significantly increased in group LuCo+ up to day 4, compared with groups noL and LuCo-. In comparison with groups noL and LuCo-, a significant decrease of the relative content of phosphatidylglycerol was obtained in group LuCo+ up to day 7. The surfactant-associated protein A was increased in group LuCo+ during the whole observation time, compared with the other groups. CONCLUSIONS: Multiple trauma leads to alterations in the surfactant system. The composition of surfactant was not further influenced by lung contusion alone. Only MTP with OF/MOF during the intensive care unit treatment showed significant alterations in surfactant composition and a decrease in lung function.

Adolescent↗
PubMed1996

[Treatment outcome of surgical thoracic wall stabilization of the unstable thorax with and without lung contusion].

Between 1988 and 1994, 295 patients with blunt chest trauma were treated. Forty-two patients had flail chest, requiring mechanical ventilation. Open reduction and osteosynthesis (ASIF reconstruction plates or isoelastic rip clamps) of the chest wall were performed in 20 patients. For the purpose of analysis we separated the patients into five groups: group I (n = 10) had chest wall stabilization in flail chest without pulmonary contusion (average ISS 31.0, AIS-thorax 4.1); group II (n = 10) had chest wall stabilization in flail chest with pulmonary contusion (average ISS 37.0, AIS-thorax 4.3); group III (n = 18) had fail chest without pulmonary contusion (average ISS 36.3, AIS-thorax 4.2); group IV (n = 4) had flail chest with pulmonary contusion (average ISS 37.8, AIS-thorax 4.0); group V (n = 29) had pulmonary contusion without flail chest (average ISS 34.5. AIS-thorax 4.1). With open reduction and internal fixation of unstable chest wall segments, the duration of ventilatory support, mortality and pneumonia were significantly reduced to 6.5 (1-25) days in group I (mortality rate 0%, incidence of pneumonia 10%) compared to group III (duration of ventilatory support 26.7 days, mortality rate 39%, incidence of pneumonia 16%). Eighty percent of the patients in group I were extubated within 5 days postoperatively. In group II 4 patients underwent emergency thoracotomy for intrathoracic injuries (3 of them died between 4 h and 31 days) and 2 patients for laceration of the lung. In all these cases the chest wall was stabilized after thoracotomy. One patient was stabilized for a deformation of the chest wall and two for paradoxical movement of the chest wall during weaning from the respirator. The mean duration of ventilation in group II was 30.8 (10-112) days (mortality rate 30%, incidence of pneumonia 30%). No complications related to the osteosynthesis arose during the follow-up. In conclusion, the best indication for early operative chest wall stabilization is flail chest without pulmonary contusion, leading to a significant reduction in the duration of ventilatory support. Secondary stabilization is recommended in patients with pulmonary contusion showing paradoxical movement of the chest wall during weaning from the respirator.

Adult↗
PubMed1996

[Emergency care and treatment costs of polytrauma patients].

Treatment costs of emergency therapy, surgery and intensive care were analysed in 20 randomly chosen, representative patients with severe multiple trauma (mean ISS 32 p). For an average stay of about 22.5 days on ICU, the total costs were DM 106924.36 (about 70,000 US $). DM 39,635.88 (= 37%) were the costs for physicians and nurses; DM 67,289.08 (= 63%) were needed for materials, X-rays, laboratory investigations, drugs and blood components. The whole treatment caused daily costs of DM 4752.22 or DM 3.30/min. The first emergency diagnostic procedures and emergency therapy take a mean time of 451.9 min from admission to the beginning of the ICU treatment and by itself already generates costs of about DM 12325.99. In Germany, a new way of compensation by a diagnosis-related group was introduced in 1996. These data suggest that treatment of severe multiple trauma is very expensive and trauma care could be economically harmful for smaller hospitals. We conclude that treatment of multiply injured patients (ISS > 16 p) should be compensated for by a special daily amount of about DM 5000 (about 3500 US $) for selected trauma centres.

Adolescent↗
PubMed1995

Does lung contusion affect both the traumatized and the noninjured lung parenchyma? A morphological and morphometric study in the pig.

Isolated unilateral lung contusion (LC) was induced in 12 pigs to determine the pathophysiological role of LC in the high mortality after multiple injury. The Horovitz quotient, pulmonary vascular resistance, mean pulmonary artery pressure, mixed venous oxygen consumption, inspiratory pressure and compliance were significantly decreased in the LC group as compared to controls. The number of polymorphonuclear granulocytes, the microvascular permeability of albumine and the Wilhelmy balance as determined by bronchoalveolar lavage were significantly increased after lung contusion. As indicators of a systemic reaction we found elevated plasma levels of the terminal complement complex and decreased levels of the complement factor 3a after LC. The morphological assessment revealed changes such as those encountered during the early phase of adult respiratory distress syndrome, with granulocyte sticking, endothelial cell adhesion and transendothelial diapedesis. Morphometric analysis demonstrated a significant decrease in alveolar diameter in both the injured and the contralateral lung due to impaired surfactant surface activity. A distinct increase in septal diameter, related to edema and caused by increased microvascular permeability, was found in the injured lungs. These findings emphasize that LC leads to a generalized impairment of the entire lung, which may lead to progressive lung failure.

Albumins↗
PubMed1995

Morphometry of experimental lung contusion: an improved quantitative method.

Alterations of lung tissue following pulmonary contusion are mainly assessed qualitatively. Quantitative examinations were limited up to now, to investigations in X-ray and computer tomography images, since morphometry of contused and normal biotic lung tissues seemed to be methodologically unfeasible. In order to overcome this shortcoming, the lungs of pigs were examined after unilateral lung contusion. In semithin sections, the thickness distribution of the interstitium and the volume distribution of the alveolar cavities were studied. Using an image analysis system a sequence of detection, erosion and skeletonisation steps were used to recognize the septal tissue correctly. The percent distributions were calculated from chord measurements after a sequence of erosion steps. It turned out that this technically simple procedure enabled highly reliable and valid results to be obtained, concerning the morphometric analysis of the alterations in the contused, as well as in the non-injured lungs.

Animals↗
PubMed1995

[Intermittent dorso-ventral positioning in therapy of severe post-traumatic lung failure].

The influence of intermittent prone positioning on pulmonary gas exchange and parenchymal densities was investigated in ten patients. Three patients fulfilled the criteria of "severe ARDS"; seven patients had moderate lung injury as documented by the "lung injury score" (LIS). Nine out of ten were trauma patients and had an average injury severity score of 32.3. The oxygenation index (paO2/FiO2) improved in all patients after prone positioning, showing an increase of 81 +/- 47 (20-197) mmHg (MV +/- SD). Total static lung compliance showed an increase of 7.6 (0-16) ml/mbar. Patients with ARDS benefitted especially from intermittent prone positioning, resulting in a substantial improvement of the LIS of 0.91 (0.75-1.0) points. In moderate lung injury the LIS improved 0.5 (0.25-1.0) points. In lung computerized tomography, we observed the disappearance of posterobasal densities. Repeated prone positioning may therefore be used in ARDS patients as well as in patients with moderate lung injury.

Adolescent↗
PubMed1994

[Primary diagnosis and follow-up after thoracic trauma and lung contusion].

In 212 patients after injury of the thorax (54 males, 158 females; penetrating (15), blunt (197), multiple trauma (128)) 158 cases demonstrated rib fractures and 103 radiological proven pneumo- or hematothoraces or sometimes both, 108 of 138 had to be drained. 96.5% of the effusions and 98% of the pneumothoraces were clinical confirmed. 93.5% of 97 pulmonary contusions (79 unilateral, 18 bilateral) were detected by bronchoscopy within 10 h, 72% by x-ray. Caused by anatomical problems or for additional diagnosis 4 patients underwent thoracic CT. During ICU treatment 31 patients developed septic complications without detection in x-ray studies. In CT (n = 64) we found: 5 empyema, 13 pleural effusions, 4 pneumothoraces, 4 pneumocysts, 72 condensations of a lobe. After CT we performed: 9 resections of the lower lobe, 1 pneumectomy, 1 decortication, 7 thoracotomies with drainage, 8 drainages. To detect a septic focus under treatment the CT proved being an important diagnostic tool in chest trauma and lung contusion.

Adult↗
PubMed1994

[Pathophysiologic consequences of various osteosynthesis procedures in polytrauma patients. Part I: Experimental studies of intramedullary pressure development in reamed and unreamed intramedullary nailing and plate osteosynthesis of the femur].

The aim of this study was to measure the intramedullary pressure (IP) of a) a reamed intramedullary nail (RN), b) an unreamed intramedullary nail (UN), and c) the AO-plate (PL) for stabilization of an experimental fracture of a sheep femur. The increase in IP whilst reaming or introducing intramedullary nails in long bone fractures is often said to be responsible for fat intravasation and secondary systemic and pulmonary damage after severe blunt trauma. 21 sheep were studied, 7 in each group (RN, UN, PL). The animal study was permitted by the local authorities. Under general anesthesia, the femoral fractures were produced by an oscillating saw, osteosynthesis was then performed whilst continuously measuring IP with a supracondylar IP-transducer-device. The results show similar intramedullary pressures measured during RN and during UN (maximal IP: UN: 203 mmHg, range 76-330; RN: 212 mmHg, range 70-425). The alternative extramedullary PL is not accompanied with any relevant increase of IP (maximal IP: 35 mmHg, range 16-70). In conclusion, RN and UN are not safe procedures concerning the danger of fat-intravasation by IP.

Animals↗
PubMed1993

[Results of treatment after conservative and surgical management of proximal humerus fractures].

The proximal fracture of the humerus is still the domain of conservative treatment. In 80% of our patients the humerus fracture was not operated. The remaining 20% were treated surgically. Neer's classification was used for a differentiated approach. In case of surgical therapy the guiding principle should be to choose the least invasive surgical treatment offering the greatest benefit. Minimal treatment should be preferred to prevent necrosis. Further, one should strive to gain an axial adjustment of the fracture rather than placing too much emphasis on compression. The aim should be an early and graded treatment and an early functional therapy. In fractures III, IV and V according to Neer, minimal osteosynthesis should be preferred. This will, if the fracture is not accompanied by other injuries and if there is adequate physiotherapy after surgery, result in a recovery of the function. In relatively young patients with solid spongiosa, good stability and anatomical restoration can be achieved by osteosynthesis. Unfortunately in fractures II and IV according to Neer, as well as in four-segment-fractures unsatisfactory results can not be avoided. In such cases minimal surgery should be performed. Implantation of a shoulder prosthesis is indicated only in case of a secondary painful arthrosis. The only cases in which primary alloarthroplasty is indicated are fractures of group II. In these cases implantation is promising because of the totally preserved muscular insertion. In four-segment and luxation fractures, atraumatic surgical reconstruction should be aimed at.

Adolescent↗
PubMed1993

[Repeated routine determination of pulmonary microvascular permeability after polytrauma].

We present a technique to measure pulmonary microvascular permeability for albumin in patients with multiple trauma by means of bronchoalveolar lavage (BAL). Routine laboratory tests for the analysis of BAL fluids are used. The results were clinically validated in 10 healthy volunteers and 12 patients with multiple trauma in a first prospective study. Additionally, another 11 severely traumatized and 24 less traumatized patients were evaluated in a second prospective study. Normal values (> 0.09 +/- 0.02), posttraumatic physiological ranges (< 0.35), and a "high risk" range (> 0.5) for pulmonary microvascular permeability for albumin were developed. There was a high correlation between the first posttraumatic values of pulmonary microvascular permeability and the required duration of intensive care treatment (r = 0.81), the duration of continuous mandatory ventilation (r = 0.78) and the mean lung injury score by Murray (r = 0.76). We conclude that the presented method is harmless and useful to describe the post-traumatic course of pulmonary microvascular permeability.

Adult↗
PubMed1992

Generation of anaphylatoxin C3a in plasma and bronchoalveolar lavage fluid in trauma patients at risk for the adult respiratory distress syndrome.

OBJECTIVE: To determine the generation of anaphylatoxin C3a in plasma and bronchoalveolar lavage fluid in trauma patients at risk for the adult respiratory distress syndrome (ARDS). DESIGN: Prospective study. SETTING: ICU in a university hospital. PATIENTS: Severely traumatized patients at risk for the ARDS (n = 25). INTERVENTION: EDTA plasma samples and bronchoalveolar lavage fluid were obtained. MEASUREMENTS AND MAIN RESULTS: Complement proteins C3, C4, C5, and the inhibitors C1-inhibitor, Factor H, and Factor I were quantitated in EDTA-plasma samples obtained every 6 hrs during the first 48 hrs after ICU admission and every morning from days 4 to 14 after injury. In bronchoalveolar lavage fluid, the complement activation production of C3a-desArg was quantitated and the volume of epithelial lining fluid was calculated. All patients showed a decrease of the complement proteins C3, C4, C5 and of the inhibitors C1-inhibitor, Factor H, and Factor I during the first 24 hrs, indicating complement consumption. Patients developing ARDS (n = 11) showed significantly higher C3 concentrations and a higher C3a/C3 ratio in the first few hours after multitrauma. Follow-up bronchoalveolar lavages demonstrated highly increased amounts of C3a in epithelial lining fluid during the first 24 hrs, mainly in ARDS patients and, to a lesser degree, in non-ARDS patients. To determine the origin of C3a in bronchoalveolar lavages, the ratio of C3a in epithelial lining fluid and plasma was calculated. CONCLUSION: The C3a of epithelial lining fluid to plasma ratio was extremely high in patients developing ARDS, but even the non-ARDS group had a ratio greater than 1, indicating that a substantial local complement activation occurs in the lung.

Adult↗
PubMed1992

Leukotriene generation in patients with multiple injuries.

We determined the generation and metabolism of lipoxygenase products in isolated granulocyte fractions of patients with multiple trauma (n = 9) and compared the results with those of healthy volunteers (n = 8). The supernatants of stimulated cells were analyzed by high-performance liquid chromatography. During the first week after injury a significantly reduced capacity to generate LTB4 and an increased metabolism of LTB4 into omega-oxidated products (20-OH-LTB4 and 20-COOH-LTB4) were observed after stimulation of the granulocytes with Ca ionophore. The depressed leukotriene production could be partly abrogated by the addition of arachidonic acid. These findings are comparable with alterations previously described in severely burned patients with postburn sepsis. Additionally, an elevated production of LTC4 by peripheral granulocyte fractions was observed in two patients suffering from adult respiratory distress syndrome (ARDS) as well as an increased number of eosinophils during the time of lung dysfunction. Analysis of bronchoalveolar lavage in patients with multiple trauma (11 patients with ARDS and 11 patients without ARDS) by a specific radio-immunoassay confirmed an elevated production of cysteinyl-leukotrienes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Surfactant protein A (SP-A) is decreased in acute parenchymal lung injury associated with polytrauma.

To further investigate if the pulmonary surfactant system is altered in acute parenchymal lung injury of adults following polytrauma we measured SP-A level and phospholipid composition in 150 sequentially obtained lung lavage samples from poly-traumatized patients (n = 19) beginning at the day of trauma and ending 18 days later or when the patient was extubated. Out of the 19 patients studied 10 had severe parenchymal lung injury (ARDS), nine had moderate lung injury. SP-A was measured using a two-monoclonal sandwich ELISA-assay. Phospholipids were separated using high-performance liquid chromatography and their composition was calculated by comparison with standard phospholipid mixtures. We found immunoreactive SP-A concentrations ranging from 0.1 micrograms ml-1 to 8.5 micrograms ml-1 lung lavage fluid obtained from all patients. The mean SP-A concentration in patients who had severe parenchymal lung injury (ARDS) was 1.06 +/- 0.16 micrograms ml-1 lavage fluid, the mean concentration in patients who had only moderate parenchymal lung injury was 1.92 +/- 0.18 micrograms ml-1 lavage fluid. Both concentrations were lower than in healthy controls (2.74 +/- 0.3 micrograms ml-1 lavage fluid; n = 12). In patients who had moderate lung injury the SP-A level normalized, but in patients who had severe lung injury the SP-A level remained low during the timespan examined. SP-A alterations did not correlate to changes in phospholipid composition as determined in lung lavage samples of individual patients. We conclude that alveolar SP-A concentrations decrease in polytraumatized patients who have acute parenchymal lung injury soon after the trauma occurs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Procoagulant activity in bronchoalveolar lavage of severely traumatized patients--relation to the development of acute respiratory distress.

In a prospective study in severely traumatized patients, procoagulant activity (PCA) was determined in bronchoalveolar lavage fluids (BAL). Bronchoscopy with lavage was serially performed during the first 15 days after injury (in total 148 samples of 25 patients). PCA was measured as recalcification times in the absence or presence of excess phosphatidylethanolamine and translated into procoagulant unit equivalents using standard thromboplastin. The data were correlated to the extent of respiratory failure in the injured patients and were compared to PCA in 29 lavage samples obtained from 10 healthy control subjects. A several-fold increase in BAL PCA was noted in all trauma victims, evident already within the first 24 h after injury. A progressive rise in PCA occurred from the 4th posttraumatic day and was highly significantly more pronounced in patients developing serious respiratory failure than in those with only mild pulmonary dysfunction. Significant correlations were noted between PCA increase and alveolar protein-leakage, granulocyte-influx and surfactant alterations, however with correlation coefficients not surpassing 0.55. We conclude that a marked increase in procoagulant activity occurs in severely injured patients, which may favour alveolar fibrin deposition and is related to the development of acute respiratory failure.

Blood Coagulation Factors↗