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Biomedical subjects

K G Kanz

Publications and source records attributed to K G Kanz.

At least 19 recordsLinked to original sources
PubMed2001

S-100b, sE-selectin, and sP-selectin for evaluation of hypoxic brain damage in patients after cardiopulmonary resuscitation: pilot study.

S-100b is thought to be a screening marker of hypoxic brain damage in patients with cardiac arrest. However, the time-dependent occurrence and relevance of increased S-100b serum levels in out-of-hospital patients with cardiopulmonary resuscitation (CPR) is still discussed. The purpose of our study was to evaluate the diagnostic utility of S-100b measurements in comparison to that of adhesion molecules sE-selectin and sP-selectin in patients with CPR. Sixteen out-of-hospital patients (median age 69.6 years; range 59.2-82.2 years) suffering from cardiac arrest due to ventricular fibrillation, asystole, or electromechanical dissociation were recruited prospectively. Blood samples were drawn on scene after the return of spontaneous circulation (ROSC) and 12 hours after successful CPR. The reference group consisted of 10 patients with isolated severe head trauma (SHT) (Glasgow Coma Score </ or =8), and the control group comprised 20 healthy volunteers. Serum concentrations of S-100b, determined by immunoluminometric assay, were compared with serum levels of sE-selectin and sP-selectin measured by an enzyme-linked immunosorbent assay and correlated with the patients' survival. In the CPR group, S-100b serum levels (2.37 ng/ml; 1.37-4.09 ng/ml) at study entry (11.6 minutes after arriving on scene) did not significantly differ from those of SHT patients (2.88 ng/ml; 1.78-8.81 ng/ml). Both groups showed significant differences from the healthy controls (0.04 ng/ml; 0.01-0.82 ng/ml). At 12 hours after CPR the serum levels had decreased to 0.41 ng/ml (0.24-0.51 ng/ml) but continued to be significantly elevated compared to that of the control group. sE-selectin values in serum increased from 56.00 ng/ml (38.50-85.50 ng/ml) on scene to 79.00 ng/ml (52.00-127.00 ng/ml) after 12 hours (p < 0.05). The first measurements differed significantly from serum levels of the control group (22.50 ng/ml; 14.00-34.00 ng/ml) and from those of the SHT group (45.00 ng/ml; 39.00-63.75 ng/ml). At 12 hours after study entry the sE-selectin values were not significantly different from those of the SHT group (51.50 ng/ml; 39.00-95.88 ng/ml). sP-selectin serum levels increased slightly from 199.50 ng/ml (184.25-227.25 ng/ml) to 247.00 ng/ml (206.50-354.75 ng/ml). First and second measurements did not reveal any significant differences in either the SHT group or the healthy controls. When correlated with survival, S-100b measurements exhibited constantly high serum levels for patients, decreasing within the first 24 hours, whereas they decreased significantly in patients with longer survival. sP-selectin values on scene slightly increased in cases of survivals less than 24 hours after CPR. sE-selectin serum levels always remained within normal levels and revealed no significance later on. In contrast to the endothelium-derived adhesion molecules sE-selectin and sP-selectin, comparison of measurements of specific neuroprotein S-100b early after cardiac arrest and 12 hours later seem to provide an indication of the severity of hypoxic brain damage and the prognosis after CPR. Further investigations are required to better understand the CPR-related mechanisms of blood-brain barrier damage.

Aged↗
PubMed2001

Evaluation of S-100b as a specific marker for neuronal damage due to minor head trauma.

Management of patients with minor head trauma (MHT) continues to be debated in the literature. Measurement of S-100b in serum has been introduced into the discussion as an additional screening tool for intracerebral injuries because routine cranial computed tomography (CCT) of a large number of patients causes logistic difficulties, and the neurologic examination is often impaired by a high frequency of coincidental intoxication. The aim of our study was to determine the diagnostic value of measuring S-100b in the serum of MHT patients to identify risk groups. Additional validity should be aquired by a comparison with plasma levels of polymorphonuclear neutrophil (PMN) elastase an established general trauma marker. A series of 52 patients with MHT were included in the prospective study. At admission the patients underwent a routine CCT scan to detect intracerebral lesions, and blood samples were drawn to investigate circulating levels of S-100b and PMN elastase. For comparison, data for a positive control group of 10 severe head trauma patients (initial Glasgow Coma Scale score < 8) and for a negative control group with 20 healthy volunteers were obtained. The interval between MHT and admission to our hospital was 73.4 +/- 47.0 minutes. The initial S-100b serum levels of MHT patients were 0.470 +/- 0.099 ng/ml, those of the positive control group were 7.16 +/- 3.77 ng/ml, and those of the negative control group were 0.05 +/- 0.01 ng/ml. Relevant pathologic CCT scans were detected in 28.8% of MHT patients; one patient of that group was subjected to immediate surgical intervention (1.9%). At a cut-off point of 0.1 ng/ml, the sensitivity of positive S-100b levels reached 100% and the specificity 40.5%. Plasma levels of PMN elastase reached 60.52 +/- 10.75 ng/ml in the MHT group, 66.4 +/- 14.92 ng/ml in the severely head-injured group, and 23.26 +/- 1.53 ng/ml in the negative control group. Serum levels of S-100b seem to be a highly sensitive but not very specific marker for isolated neurotrauma. Measurement of this parameter may be helpful as an additional screening tool to identify high risk groups in the cohort of MHT patients.

Autoantigens↗
PubMed2001

Early cellular brain damage and systemic inflammatory response after cardiopulmonary resuscitation or isolated severe head trauma: a comparative pilot study on common pathomechanisms.

Severe neurological deficits are common characteristics of patients surviving cardiopulmonary resuscitation (CPR) or isolated severe head trauma (SHT). For comparative evaluation of underlying pathomechanisms, 22 patients with out-of-hospital cardiac arrest and successful CPR as well as 10 patients with SHT were included in our prospective study. Circulating S-100B was determined as an indicator of cellular brain damage. Interleukin-8 (IL-8), soluble E-selectin (sE-selectin) and polymorphonuclear (PMN-) elastase were measured as markers of systemic inflammation following whole body ischaemia and reperfusion injury. Venous blood samples were drawn on scene (median time 11.0 min after starting basic life support) and in the intensive care unit (median time 12.5 h thereafter) in CPR patients and at admission to hospital (median time 43.8 min after trauma) and approx. 12 h later in SHT patients. Biochemical parameters in these samples were compared with specimens taken from 20 healthy volunteers. Initial median S-100B levels of the CPR and SHT patients were both significantly increased compared with the controls. Twelve hours later, significant falls in S-100B revealed no differences between the two patient groups, but did not reach control values. Median IL-8 and sE-selectin levels entry to the study were elevated in both patient groups compared with controls and showed further rises within the following 12 h. Finally, increased initial median levels of PMN-elastase revealed significant differences between the patient groups and between patients and controls. Twelve hours later, median PMN-elastase values were equally elevated in the CPR and SHT subjects. Our preliminary data suggest similar pathomechanisms occurring after both CPR and SHT. Both clinical entities seem to be associated with early transient cellular brain damage as shown by prolonged rapidly increasing and subsequent fall in S-100B serum levels. In contrast, the prolonged elevation of circulating IL-8, sE-selectin and PMN-elastase may indicate a very similar systemic inflammatory response by endothelial cells and neutrophils initiated by ischaemia and reperfusion injury in both conditions. Further studies should be carried out to determine the cause and the prognostic value of these biochemical parameters in relation to long-term neurological outcome.

Aged↗
PubMed2000

Influence of alcohol exposure on S-100b serum levels.

Recent assessment of the glia cell-derived neuroprotein S-100b in serum has been considered as a screening method for possibly occult brain injury in patients with minor head trauma (MHT). Since MHT is associated with alcohol intoxication in up to 50% of patients requiring emergency treatment, the blood-brain barrier (BBB) as well as neuronal cell integrity may be also affected by alcohol abuse. So far, however, no valid data are available on the release of S-100b after alcohol exposure. Thus, the aim of our study was to investigate S-100b serum levels in a controlled alcohol exposure paradigm. 22 healthy volunteers were included in the study, blood samples were drawn prior to and about 90 minutes after drinking. The amount of alcohol was adjusted to the body weight. A mean of 66.7 +/- 14.81 g was consumed giving raise to a blood alcohol concentration of 0.827 +/- 0.158@1000. S-100b serum levels assayed by a luminescence immunoassay were compared with those of MHT patients. The still preliminary results suggest no increase of the serum S-100b levels (0.0509 +/- 0.048 ng/ml versus 0.0422 +/- 0.044 ng/ml) after moderate alcohol consumption. In contrast, MHT patients with alcohol intoxication (1.6 +/- 0.77@1000) revealed a significant up to 10fold elevation of S-100b serum levels. Because of the much higher blood alcohol concentration in the MHT patients compared to the control collective, a potential relationship between excessive alcohol consumption and the release of S-100b in minor head trauma can still not be excluded. Further investigations on this topic are in progress.

Adult↗
PubMed2000

S-100b as a screening marker of the severity of minor head trauma (MHT)--a pilot study.

Due to its neural tissue specificity S-100b is considered as a screening marker of cerebral injury in head trauma patients. However, the occurrence and relevance of an increased S-100b serum level in minor head trauma (MHT) is still debated. Therefore, the purpose of our study was to evaluate the diagnostic utility of S-100b measurements in a level I trauma center emergency room (ER). Eighty patients presenting with clinical symptoms of MHT (GCS score of 13-15, transitory loss of consciousness, amnesia, nausea) were prospectively recruited. Blood samples were drawn at 0 h, 6 h and 24 h after admission, and a cerebral computed tomography (CT) was performed. The reference group consisted of 10 patients with severe head injury (GCS score < 8), the control group of 20 healthy volunteers. Concentrations of S-100b in serum were determined by an immunoluminometric assay. The results were compared with the plasma levels of polymorphonuclear (PMN) elastase as an established general trauma marker. In the MHT group, the S-100b serum level revealed 1.26 +/- 0.57 ng/ml at study entry (73.46 +/- 47.53 min after trauma). In comparison, the S-100b concentration was significantly elevated in patients with severe head trauma (5.26 +/- 1.65 ng/ml, p = 0.009), but no significant difference became evident in relation to the control group (0.05 +/- 0.01 ng/ml). Starting values of PMN elastase in plasma amounted to 66.40 +/- 14.92 ng/ml in severe trauma, and to 60.52 +/- 10.75 ng/ml in MHT showing significant differences only in relation to the control group (23.36 +/- 1.53 ng/ml). When correlated with the severity of the later clinical course, the first S-100b measurements exhibited steadily increasing values as demonstrated in MHT outpatients (0.29 +/- 0.11 ng/ml), MHT in-hospital patients (0.70 +/- 0.19 ng/ml) and MHT intensive care unit patients (5.03 +/- 3.18 ng/ml). PMN elastase levels revealed no significant differences concerning the three MHT subgroups. Thus, in contrast to the general trauma marker PMN elastase, assessment of the specific neuroprotein S-100b early after traumatic insult appears to be a promising laboratory marker for the prognosis of the severity of brain injury in MHT patients. Nevertheless, further investigations are required to better understand its predictive value.

Biomarkers↗
PubMed2000

Do we face a fourth paradigm shift in medicine--algorithms in education?

Medicine has evolved toward rationalization since the Enlightenment, favouring quantitative measures. Now, a paradigm shift toward control through formalization can be observed in health care whose structures and processes are subjected to increasing standardization. However, educational reforms and curricula do not yet adequately respond to this shift. The aim of this article is to describe innovative approaches in medical education for adapting to these changes. The study design is a descriptive case report relying on a literature review and on a reform project's evaluation. Concept mapping is used to graphically represent relationships among concepts, i.e. defined terms from educational literature. Definitions of 'concept map', 'guideline' and 'algorithm' are presented. A prototypical algorithm for organizational decision making in the project's instructional design is shown. Evaluation results of intrinsic learning motivation are demonstrated: intrinsic learning motivation depends upon students' perception of their competence exhibiting path coefficients varying from 0.42 to 0.51. Perception of competence varies with the type of learning environment. An innovative educational format, called 'evidence-based learning (EBL)' is deduced from these findings and described here. Effects of formalization consist of structuring decision making about implementation of different learning environments or about minimizing variance in teaching or learning. Unintended effects of formalization such as implementation problems and bureaucracy are discussed. Formalized tools for designing medical education are available. Specific instructional designs influence students' learning motivation. Concept maps are suitable for controlling educational quality, thus enabling the paradigm shift in medical education.

Algorithms↗
PubMed2000

[Implementation of a quality management system for the curriculum in emergency medicine education].

Medical teaching, training and education in basic and advanced life support were improved by basic quality management procedures. 3rd year medical students (n = 276) of two consequent semesters were questionnaired about their acute emergency medicine curriculum. While Group A (n = 134) received a standard course, the new course for group B (n = 142) was reorganised on the basis of the results of group A. Interventive educational measures were an increased number of models provided for exercising the students skills, and an extension of megacode training possibilities. Participation of students in course design improved the overall performance in respect of knowledge, skills and decision-making (p < 0.05). Curriculum acceptance and intrinsic motivation of students however were not positively influenced by practical training compared to traditional knowledge transfer.

Curriculum↗
PubMed2000

Tensor fasciae latae perforator flap for reconstruction of composite Achilles tendon defects with skin and vascularized fascia.

The surgical management of large defects of the Achilles tendon and overlying skin is very demanding and necessitates, as a rule, a free vascularized graft. The ideal characteristics of a thin layer of skin and a strong tendon component, combined with a reliable blood supply and minimal morbidity at the donor site, have only been partially met by all previous grafts used in this situation. The authors performed reconstructions in five patients with large defects of the Achilles tendon and overlying skin by using a perforator flap derived from the tensor fasciae latae flap. A vascularized skin-subcutis-fascia lata flap could be raised by dissecting out two to three perforating arteries through the tensor fasciae latae muscle to the ascending branch of the lateral circumflex femoral artery; the muscle was left in situ in the process. All the flaps took well without complications. At final examination after an average of 20 months, the reconstructed Achilles tendon showed good functional results, although there was a 50 to 70 percent reduction in power during plantar flexion when compared with the normal side. A very good aesthetic result could be obtained after a debulking operation was performed on the skin flap.

Achilles Tendon↗
PubMed1998

[New aspects of electric defibrillation].

Early defibrillation is the standard of care for patients with ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). Technical developments aim at further miniaturization and simplification of defibrillators as well as adaptation of energy requirements to the patient's needs. Implantable Cardioverter-Defibrillators (ICD) and automated external defibrillators (AED) are based upon the same technology. Both devices analyze the ECG signal internally, followed by a "shock" or "no shock" decision. Use of automated devices is the prerequisite for defibrillation by non-physicians. Chest impedance measurements and use of alternative shock waveforms, such as biphasic, aim at adaptation of energy or current to the patient's individual needs and avoid application of unnecessarily high amounts of energy to the myocardium. Calculation of median frequency is a non-invasive method for analyzing the heart's metabolic and electrical state. It helps to determine the optimal moment for defibrillation during cardiopulmonary resuscitation (CPR). Developments concerning the structure of in-hospital emergency systems or pre-hospital emergency medical services (EMS) aim at further reductions in time from collapse of a patient until first defibrillation. Such developments include early defibrillation programs for emergency medical technicians (EMT), nurses, and fire or police department first responders as well as wide distribution of easy-to-operate defibrillators in public areas, as discussed during the American Heart Association's Public Access Defibrillation conferences. All programs of that kind have to be organized and supervised by a physician who is responsible for training and supervision of the personnel involved.

Arrhythmias, Cardiac↗
PubMed1998

Improvement in the therapy of multiply injured patients by introduction of clinical management guidelines.

A trauma algorithm representing the guidelines for the management of emergency treatment of severe blunt trauma was implemented at our institution in 1994. By comparison of two prospectively recorded cohorts of multiply injured patients, the clinical efficacy of these guidelines was analysed. The algorithm cohort comprised 74 patients over the period January 1994 to June 1996, and the Control cohort 126 patients over the period April 1988 to December 1993. To evaluate procedural quality of early clinical trauma management, nine criteria were applied. After implementation of the algorithm there was an improvement in all parameters reflected by a significant reduction of missed injuries and important time savings. Mortality rates in the cohorts were calculated after subdivision into three groups (I-III) with moderate (ISS: 18-24), high (ISS: 25-49) and very high (ISS: 50-75) injury severity. All cohort subgroups were comparable with respect to ISS values, age, initial loss of consciousness (GCS) and shock rate. In all subgroups of the algorithm cohort mortality rates were reduced: group I: 0 versus 20 per cent (p < 0.05); group II: 8 versus 24 per cent (p < 0.05); group III: 40 versus 71 per cent. Improvements in both therapeutic process and outcome were observed after implementation of the trauma algorithm.

Adult↗
PubMed1997

[Algorithms in trauma management].

A well-controlled, meticulous process has a far higher probability of resulting in a high quality of medical care than improvization and unstructured creativity. Algorithms display decision-making treatment processes and problem-solving strategies by giving clearly defined and formalized guidelines. The flow chart for decision-making follows the yes/no dichotomy of binary logic. The systematic ordering of decision points and consequent actions is guided by medical priority and thus regulates the time-frame and sequence of each single step in a logical manner. With the help of clinical algorithms highly complex processes such as the management of the severely injured patient can be translated into a clearly structured, logical pathway. Clinical algorithms represent scientifically recognized treatment rules, indicate a solution for solving problems and help users to organize ideas and recognize connections. They delineate a consistent and valid guideline, while allowing deviations in proven exceptions. The use of algorithms allows a systematic search for errors in the process of quality management. In emergency situations they suggest a structured means of problem solving for the less experienced user. Algorithms are useful instruments in the teaching of medical decision-making.

Algorithms↗
PubMed1997

Low-energy impedance-compensating biphasic waveforms terminate ventricular fibrillation at high rates in victims of out-of-hospital cardiac arrest. LIFE Investigators.

INTRODUCTION: New automatic external defibrillators (AEDs), which are smaller, lighter, easier to use, and less costly make the goal of widespread AED deployment and early defibrillation for out-of-hospital cardiac arrest feasible. The objective of this study was to observe the performance of a low-energy impedance-compensating biphasic waveform in the out-of-hospital setting on 100 consecutive victims of sudden cardiac arrest. METHODS AND RESULTS: AEDs incorporating a 150-J impedance-compensating biphasic waveform were used by 12 EMS systems. Data were obtained from the AED PC card reporting system. Defibrillation was defined as conversion to an organized rhythm or to asystole. Endpoints included: defibrillation efficacy for ventricular fibrillation (VF); restoration of an organized rhythm at the time of patient transfer to an advanced life support (ALS) team or to the emergency department (ED); and time from AED power-on to first defibrillation. The AED correctly identified 44 of 100 patients presenting in VF as requiring a shock (100% sensitivity) and 56 of 100 patients not in VF as not requiring a shock (100% specificity). The time from 911 call to first shock delivery averaged 8.1 +/- 3.0 minutes. A single 150-J biphasic shock defibrillated the initial VF episode in 39 of 44 (89%) patients. The average time from power-on to first defibrillation was 25 +/- 17 seconds. At patient transfer to ALS or ED care, an organized rhythm was present in 34 of 44 (77%) patients presenting with VF. Asystole was present in 7 (16%) and VF in 3 (7%). CONCLUSIONS: Low-energy impedance-compensating biphasic waveforms terminate long-duration VF at high rates in out-of-hospital cardiac arrest. Use of this waveform allows AED device characteristics consistent with widespread AED deployment and early defibrillation.

Adult↗
PubMed1997

[A time and priority-oriented algorithm].

Algorithms represent a graphical display of decision-making by giving clearly defined and formalized guidelines. The systematic order of decisions and consequent actions is guided by medical priority and regulates the time frame and sequence of each single step in a logical manner. With the help of clinical algorithms highly complex processes such as the management of the severely injured patient can be translated into a clearly structured, logical pathway. They delineate a consistent and valid guideline but require aberrations in proven exceptions. The use of algorithms allows a systematic search for errors in the process of quality management. In emergency situations they suggest a structured way of problem-solving to the less experienced user. Algorithms are useful instruments in teaching medical decision-making.

Algorithms↗
PubMed1996

[Preclinical diagnosis and management in severe craniocerebral trauma].

Both prehospital and hospital management of patients with severe head injury has clearly improved in the last decades. There is a greater knowledge of how secondary brain injury is caused and how it can be prevented. Intracranial mechanisms (e.g. haematoma and elevated intracranial pressure and systemic mechanism (e.g. shock and hypoxaemia) are two of the major causes of secondary brain injury. Adequate prehospital evaluation and treatment determine the later outcome for the patient. The Glasgow Coma Scale has become the standard score for assessing the level of consciousness. Early prehospital treatment must prevent secondary brain damage through adequate oxygenation (intubation, ventilation) and a sufficient cerebral perfusion pressure (treatment of shock). The neck of the patient should be positioned straight and the upper part of the body should be elevated to about 30 degrees. The prophylactic use of steroids, mannitol or high dose barbiturates is not indicated. Aggressive hyperventilation (pCO2 < 30 mmHg), especially during the first few days after severe brain injury, should be avoided.

Brain Damage, Chronic↗
PubMed1994

[An algorithm for management of shock in polytrauma].

The initial management of patients with multiple trauma requires a well-defined plan of action for immediate and adequate therapy, that ensures fast recognition of life-threatening conditions and injuries. While treatment protocols for specific situations and injuries are fairly well defined, there are few such concepts for the overall management process. Therefore, we designed a comprehensive algorithm for in-hospital trauma care to give priority-based guidelines to the trauma room physician. The full management plan (diagnostic and therapeutic interventions in sequence) is implemented in seven flow charts. The first algorithm starts with the initial assessment of immediate life-threatening disorders of A (airways), B (breathing) and C (circulation) and is followed by the early stabilization and maintenance of vital functions. It is followed by six interrelated flow charts, based on disturbed physiological functions (respiration, circulation) and anatomical injuries (thorax, abdomen, head/brain, spine/pelvic girdle/extremities), which are worked up simultaneously and repeatedly. This algorithm is not only intended as an overall guideline for use the management of severely injured patients, but is also indispensable for quality assurance.

Algorithms↗
PubMed1994

[Development of clinical algorithms for quality assurance in management of multiple trauma].

Resuscitation and management of high-risk multiple trauma patients require a systematic and coordinated approach to diagnostic and therapeutic interventions. Clinical algorithms with branch chain decision logic can provide a clear and organized transformation of clinical standards for trauma care. Owing to their capability in formalization and standardization, algorithms define precisely the process of care and serve as a central interface within the system of quality assurance and quality control. The standardized document symbols and conventions for information processing according to ANSI/ISO/CCITT regulations are generally applied to the flowchart design of clinical algorithms. Special starting and ending point symbols make it possible to break down complex processes in several single interrelated algorithms. Inclusion of optional criteria checklists reduces the number of decision nodes and loops and minimizes the extent of a comprehensive algorithm. Clinical algorithms are an excellent tool for converting highly complex concepts of multiple trauma management into a logical, prioritized and systematic process of care.

Algorithms↗