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Biomedical subjects

K Ullrich

Publications and source records attributed to K Ullrich.

At least 19 recordsLinked to original sources

Benchmarking as a tool of continuous quality improvement in postoperative pain management.

BACKGROUND AND OBJECTIVE: Quality of acute pain management is far from being satisfactory. These deficits are not caused by the complexity of the medical problem but by difficulties in organization and hospital structures, sand procedures. Continuous quality improvement is a recommended tool to overcome such difficulties and to increase quality in the long run. This study reports the implementation of benchmarking-based continuous quality improvement to improve postoperative pain management at a university hospital. METHODS: A specialised pain nurse interviewed patients of three surgical departments on the first day after surgery, and continuously assessed process and outcome quality parameters. A multidisciplinary team of anaesthetists, surgeons, nurses and pharmacists implemented a regular procedure of data analysing and internal benchmarking. Results and suggested improvements were fed back to the healthcare teams. RESULTS: From 1998 to 2002, 6,756 patients were assessed. Average pain on ambulation and maximal pain were 3.7 +/- 2.4 and 5.0 +/- 2.5 (mean +/- SD) on a 11-point numeric rating scale. Pain intensity at rest was 1.9 +/- 1.8. Over time, pain intensity on ambulation decreased (P = 0.022) whereas maximal pain and pain at rest remained unchanged. There was an increase in the number of patients who received non-opioid analgesia (P < 0.001). CONCLUSIONS: A continuous quality improvement process could be established and is now successfully used in clinical routine. Cornerstones of this project were frequent assessments of process and outcome parameters, regular benchmarking and implementation of feedback mechanisms. Changes in organization of medical management and multidisciplinary teamwork seem to be more important than medical or technical aspects.

Abdomen↗

Heparan sulfate levels in mucopolysaccharidoses and mucolipidoses.

Glycosaminoglycans are accumulated in both mucopolysaccharidoses (MPS) and mucolipidoses (ML). MPS I, II, III and VII and ML II and ML III patients cannot properly degrade heparan sulphate (HS). In spite of the importance of HS storage in the metabolic pathway in these diseases, blood and urine HS levels have not been determined systematically using a simple and economical method. Using a new ELISA method using anti-HS antibodies, HS concentrations in blood and urine were determined in MPS and ML II and ML III patients. HS concentrations were determined in 156 plasma samples from MPS I (n = 23), MPS II (n = 26), MPS III (n = 24), MPS IV (n = 62), MPS VI (n = 5), MPS VII (n = 5), ML II (n = 8) and ML III (n = 3), and 205 urine samples from MPS I (n = 33), MPS II (n = 33), MPS III (n = 30), MPS IV (n = 82), MPS VI (n = 7), MPS VII (n = 9), ML II (n = 8) and ML III (n = 3). The ELISA method used monoclonal antibodies against HS. MPS I, II, III and VII and ML II and III patients had significant elevation in plasma HS, compared to the age-matched controls (p < 0.0001). Eighty-three out of 89 (93.3%) of individual values in the above MPS types and ML were above the mean +2SD of the controls. In urine samples, 75% of individual values in patients with those types were above the mean +2SD of the controls. In contrast to the previous understanding of the HS metabolic pathway, plasma HS levels in all five MPS VI and 15% of MPS IV patients were elevated above the mean +2SD of the controls. These findings suggest that HS concentration determined by ELISA, especially in plasma, could be a helpful marker for detection of the most severe MPS I, II, III, VI and VII and ML II, distinguishing them from normal populations.

Adolescent↗

Decreased plasma concentration of von Willebrand factor antigen (VWF:Ag) in patients with glycogen storage disease type Ia.

Despite highly increased blood lipids, patients with glycogen storage disease type Ia (GSD Ia) do not develop premature vascular complications. Since this could be due to changes of coagulation factors, coagulation tests (including von Willebrand factor (VWF) antigen (VWF:Ag) ELISA, VWF:collagen binding activity (VWF:CB) and VWF multimer analysis) were performed in 10 GSD Ia patients, single cases of other GSD types, and in both healthy and hyperlipidaemic controls. In 60% of GSD Ia patients we found abnormal results, with a decrease of VWF:Ag and multimer analysis showing reduced intensity of individual oligomers in the presence of all multimers with a normal triplet structure. We interpret these findings as an acquired 'von Willebrand syndrome type I' in GSD Ia. The underlying metabolic mechanism and a potential role in the protection from vascular complication still needs to be evaluated.

Adolescent↗

Keratan sulphate levels in mucopolysaccharidoses and mucolipidoses.

The mucopolysaccharidoses (MPS) is characterized by accumulation of glycosaminoglycans (GAGs), and mucolipidosis (ML) by accumulation of GAGs and sphingolipids. Each type of MPS accumulates specific GAGs. The lysosomal enzymes N-acetylgalactosamine-6-sulphate sulphatase and beta-galactosidase involve the stepwise degradation of keratan sulphate (KS). Deficiency of these enzymes results in elevation of KS levels in the body fluids and in tissues, leading to MPS IV disease. In this study, we evaluated blood and urine KS levels in types of MPS and ML other than MPS IV. Eighty-five plasma samples came from MPS I (n = 18), MPS II (n = 28), MPS III (n = 20), MPS VI (n = 3), MPS VII (n = 5) and ML (n = 11) patients while 127 urine samples came from MPS I (n = 34), MPS II (n = 34), MPS III (n = 32), MPS VI (n = 7), MPS VII (n = 9) and ML (n = 11) patients. KS levels were determined using the ELISA method. Plasma KS levels varied with age in both control and patient populations. In all age groups, the mean values of plasma KS in MPS and ML patients were significantly higher than those in the age-matched controls. Plasma KS values in four newborn patients were above the mean + 2SD of the age-matched controls (mean, 41 ng/ml). Overall, 85.9% of individual values in non-type IV MPS and ML patients were above the mean + 2SD of the age-matched controls. For urine KS levels, 24.4% of individual values in patients were above the mean + 2SD of the age-matched controls. In conclusion, KS in blood is elevated in each type of non-type IV MPS examined, in contrast to the conventional understanding. This finding suggests that measurement of KS level provides a new diagnostic biomarker in a wide variety of mucopolysaccharidoses and mucolipidoses in addition to MPS IV.

Adolescent↗

3-Hydroxyglutaric acid fails to affect the viability of primary neuronal rat cells.

Glutaric aciduria type I (GA I) is an autosomal recessive inherited metabolic disorder caused by deficiency of glutaryl-CoA dehydrogenase (GCD) resulting in the accumulation of 3-hydroxyglutaric acid (3OHG), glutaric acid and glutaconic acid in body fluids. GA I is characterized by a specific age- and brain region-dependent neuropathology. Previous studies using organotypic slice cultures of rats and primary chick embryo telencephalon cell cultures indicated that death of neurons is a consequence of an excitotoxic mechanism induced by 3OHG. We used primary neuronal cells of neonatal rats as a model system to test cell viability after treatment with 3OHG. Western blot analysis was used to prove the expression of functional N-methyl-D-aspartate (NMDA) receptors revealing no alteration in the expression of NMDA-2a and -2b receptor subtypes in response to 3OHG. When neuronal cells cultured for 10 or 20 days were treated with 1 mM glutamate, the viability of cells was reduced by 40%. This effect could be prevented by coincubation with the NMDA receptor antagonist MK801. In contrast, incubation of cells with 3OHG for up to 24 h in concentrations of 4-8 mM did not cause increased cell death as compared with untreated control cultures. These results indicate that 3OHG is not excitotoxic in this model of neuronal rat cell cultures despite the presence of functional NMDA receptors. Therefore, alternative or additional pathomechanisms than excitotoxicity may be relevant for neurodegeneration in GA I.

Acids↗

Efficiency of long-term tetrahydrobiopterin monotherapy in phenylketonuria.

Phenylketonuria, an inborn error of phenylalanine metabolism, occurs with a frequency of about 1 in 10,000 births and is treated with a strict dietary regimen. Recently, some patients with PKU have been found to show increased tolerance towards phenylalanine intake while receiving tetrahydrobiopterin (BH(4)) supplementation. We have treated two infants with BH(4)-responsive PKU with BH(4) for more than 2 years. No additional dietary control was required to maintain blood phenylalanine concentrations in the desired range. Both children have shown normal development. Generally, our results suggest that BH(4) treatment might be an option for some patients with mild PKU, as it frees them from dietary restrictions and thus improves their quality of life.

Biopterins↗

Excitotoxicity and bioenergetics in glutaryl-CoA dehydrogenase deficiency.

Glutaryl-CoA dehydrogenase deficiency is an inherited organic acid disorder with predominantly neurological presentation. The biochemical hallmark of this disease is an accumulation and enhanced urinary excretion of two key organic acids, glutaric acid and 3-hydroxyglutaric acid. If untreated, acute striatal damage is often precipitated by febrile illnesses during a vulnerable period of brain development in infancy or early childhood, resulting in a dystonic dyskinetic movement disorder. 3-hydroxyglutaric and glutaric acids are structurally similar to glutamate, the main excitatory amino acid of the human brain, and are considered to play an important role in the pathophysiology of this disease. 3-hydroxyglutaric acid induces excitotoxic cell damage specifically via activation of N-methyl-D-aspartate receptors. It has also been suggested that secondary amplification loops potentiate the neurotoxic properties of these organic acids. Probable mechanisms for this effect include cytokine-stimulated NO production, a decrease in energy metabolism, and reduction of cellular creatine phosphate levels. Finally, maturation-dependent changes in the expression of neuronal glutamate receptors may affect the vulnerability of the immature brain to excitotoxic cell damage in this disease.

Amino Acid Metabolism, Inborn Errors↗

Vascular dysfunction as an additional pathomechanism in glutaric aciduria type I.

The metabolic hallmark of glutaric aciduria type I (GA I) is the deficiency of glutaryl-CoA dehydrogenase (GCDH) with subsequent accumulation of glutaric acid, 3-hydroxglutaric acid (3-OH-GA) and glutaconic acid. Current concepts regarding pathomechanisms of GA I focus on investigations of excitotoxic effects of 3-OH-GA. To identify pathogenetically relevant genes, microarray analyses were performed using brain material from GCDH-deficient (GCDH (-/-)) and control mice. These microarray data confirmed recent pathogenic models, but also revealed alterations in genes that had previously not been correlated to the disease, e.g. genes concerning vascular biology. Subsequent in vitro and in vivo experiments confirmed direct effects of 3-OH-GA on vascular permeability and endothelial integrity. Clinical observations underscore the involvement of vascular dysfunction. In MRI scans of GA I patients, subdural effusions as well as dilated transarachnoid vascular plexuses were detected independently of encephalopathic crises. In fact, some of these findings are already detectable shortly after birth. MRI scans of a GA I patient performed during an acute encephalopathic crisis detected a dilated intrastriatal vasculature with perivascular hyperintensity, indicating local extravasation. In conclusion, we hypothesize that 3-OH-GA affects prenatal development of vessels, thus leading to an increased vulnerability of endothelial structures and subsequent vascular dysfunction. These observations display an additional pathomechanism in GA I and might explain frontotemporal hypoplasia and chronic subdural effusions in this disease. Elucidation of the pathomechanisms of vascular dysfunction may give further insights into the pathogenesis of GA I.

Amino Acid Metabolism, Inborn Errors↗

Maintenance treatment of glutaryl-CoA dehydrogenase deficiency.

This paper summarizes the published experience as well as results of the 3rd International Workshop on Glutaryl-CoA Dehydrogenase Deficiency held in October 2003 in Heidelberg, Germany, on the topic treatment of patients with glutaryl-CoA dehydrogenase (GCDH) deficiency. So far no international recommendation for treatment of GCDH deficiency exists. Such an approach is hampered by several facts, namely the lack of an in-depth understanding of the pathophysiology of the disease, the lack of prospective studies, including the evaluation of drug monotherapy, and lack of objective documentation of clinical changes (e.g. video documentation) during pharmacotherapy.

Amino Acid Metabolism, Inborn Errors↗

A hypothesis on the biochemical mechanism of BH(4)-responsiveness in phenylalanine hydroxylase deficiency.

We describe six children with tetrahydrobiopterin (BH(4)) responsive phenylalanine hydroxylase (PAH) deficiency. All patients carry two mutant alleles in the PAH gene. Cofactor deficiency was excluded. The effect of BH(4) administration was studied by correlating different oral BH(4) doses with plasma phenylalanine levels under defined protein intake. Our results indicate that oral BH(4) supplementation may be used as long-term treatment for individuals with BH(4)-responsive PAH deficiency, either without or in combination with a less restrictive diet. Previous in vitro studies have demonstrated that BH(4) inhibits PAH tetramers but activates PAH dimers. This may indicate, that BH(4)-responsiveness results from BH(4) induced stabilization of mutant PAH dimers. In addition, interindividual differences in the cellular folding apparatus may determine the tertiary structure and the amount of mutant PAH dimers and hence may account for divergent BH(4)-responsiveness reported for the same PAH genotype.

Biopterins↗

Glutaric aciduria I: creatine supplementation restores creatinephosphate levels in mixed cortex cells from rat incubated with 3-hydroxyglutarate.

The pathogenesis of neurological sequelae in glutaric aciduria I (GA I) is still unclear. Some evidence exists for compromised energy generation in the brain of patients with GA I resulting in 'slow-onset' excitotoxicity. Previously, we have shown a reduced activity of the mitochondrial ATPsynthase in cultured mixed cortex cells from neonatal rats incubated with 2-4mM 3-hydroxyglutarate (3-OH glut) for 24h. In the present study we measured cellular contents of high energy phosphate compounds (creatinephosphate CP, ATP, and ADP) in this model after a 24h incubation period with 2-4mM glutarate (glut) or 3-OH glut. 3-OH glut specifically led to a reduction of CP content in a dose-dependent manner, whereas concentrations of ATP, ADP, and AMP remained unchanged. The drop in CP-concentration could be prevented by preincubation with the non-competitive NMDA-receptor antagonist MK 801 or coincubation with 1mM creatine. NMDA-receptor associated ion channels may be opened due to a lack of energy inside the neurons caused by a reduction of CP. This is followed by membrane depolarization which could impair electrogenic creatine transport into the cell.

Adenine Nucleotides↗

Investigation of the cerebral energy status in patients with glutaric aciduria type I by 31P magnetic resonance spectroscopy.

In vivo phosphorus magnetic resonance spectroscopy (MRS) was used to investigate markers of the cerebral energy status in two patients with glutaric aciduria type I (GA-I). Besides an increased concentration of phosphomonoesters in one patient, no other significant alterations from controls were found. This might indicate increased resynthesis of dendritic processes secondary to preceding metabolic crises. In contrast to previous cell-culture studies, no cerebral depletion of phosphocreatine (PCr) was observed. In conclusion, a severe global and permanent depletion of cerebral energy supplies must be ruled out. The benefit of a permanent creatine substitution to stabilize mitochondrial energy metabolism seems thus questionable. However, as MRS was performed during stable clinical conditions, the possibility of a PCr decrease during acute metabolic crises cannot be assessed.

Adenosine Triphosphate↗

Infantile cobalamin deficiency with cerebral lactate accumulation and sustained choline depletion.

A remarkable, intermittent sudden-onset vigilance and movement disorder in an exclusively breast-fed infant is reported, which was caused by cobalamin depletion due to maternal vitamin B12 malabsorption. The lack of cobalamin caused a severe encephalopathy in the infant, whose brain displayed a striking loss of volume and a delay of myelination. Proton magnetic resonance spectroscopy revealed an accumulation of lactate in the gray and white matter of the brain and a sustained depletion of choline-containing compounds in the white matter, reflecting a reversible disturbance of oxidative energy metabolism in brain cells and a long-lasting hypomyelination disorder. The clinical picture in conjunction with MRI and spectroscopic data of this case study yields more insight into the functions of cobalamin in the cerebral metabolism.

Brain Diseases↗

[The use of the infraclavicular plexus catheter for treatment of perioperative and chronic pain].

OBJECTIVES: The aim of this prospective study was to evaluate the vertical infraclavicular approach to the brachial plexus for the insertion of a catheter to achieve continuous analgesia in postoperative patients and patients with chronic upper limb pain. METHODS: The brachial plexus was identified using the technique described by Kilka et al. and a flexible catheter (diameter 0.85 mm) was introduced 3-5 cm into the perineural sheath via the punction cannula. Regional analgesia was achieved by intermittent injection of local anaesthetic agent. Placement of the catheter, duration and effectiveness of treatment, complications and reasons for catheter removal were recorded using a standard protocol. RESULTS: A total number of 226 plexus catheters were placed in 210 patients. Consecutive regional analgesia for at least 48 h was possible in 88%. Analgesia was sufficient in 76% of patients up to the time of catheter removal. The median (minimum-maximum) duration of catheterisation in the whole collective was 7 days (1-240) and 11 days in patients with chronic pain. Almost 30% of the patients were treated for 10 days or longer and 4.4% were treated for 1 month or longer. Major complications occurred in only three cases, while technical problems and minor complications (redness at puncture site) occurred in 10% of cases. CONCLUSIONS: The placement of an infraclavicular plexus catheter is a suitable method for pain management in the upper limb. This approach may have advantages in patients with severe injuries who cannot abduct the arm. Our results are encouraging in terms of catheterisation time, patient comfort and incidence of complications.

Anesthetics, Local↗

Individual blood-brain barrier phenylalanine transport in siblings with classical phenylketonuria.

Recent studies indicate that individual blood-brain transport characteristics of phenylalanine may lead to different clinical outcomes in phenylketonuria (PKU) patients in spite of comparable dietary control. To check these preliminary data, we investigated four pairs of siblings with classical PKU (and identical genotype) using in vivo nuclear magnetic resonance spectroscopy in the course of an oral phenylalanine load (100 mg/kg body weight). Patients' brain phenylalanine concentrations were different in spite of similar blood levels. Interindividual variations of the apparent transport Michaelis constant, Kt,app, ranged from 0.10 to 0.84 mmol/L. The ratio of the maximal transport velocity, Tmax, over the intracerebral consumption rate, Vmet, varied between 2.61 and 14.0. Siblings with lower values for Kt,app, higher values for Tmax/Vmet, and higher concurrent brain phenylalanine levels showed a lower IQ and a higher degree of cerebral white matter abnormalities. The results indicate that blood-brain barrier transport characteristics and the resultant brain phenylalanine levels are causative factors for the individual clinical outcome in PKU.

Adolescent↗

Individual blood-brain barrier phenylalanine transport determines clinical outcome in phenylketonuria.

Different clinical outcomes in spite of comparable dietary controls are well known in patients with phenylketonuria. Currently, reasons for this phenomenon are unknown. Kinetic investigations in 15 patients with classic phenylketonuria were performed using in vivo nuclear magnetic resonance spectroscopy before and after an oral phenylalanine load (100 mg/kg body weight). Patients' brain phenylalanine concentrations were quite different in spite of similar blood phenylalanine levels. Interindividual variations of the apparent transport Michaelis constant, K(t,app), covered a range from 0.10 to 1.03 mmol/L. The ratio of the maximal transport velocity, Tmax, over the intracerebral consumption rate, Vmet, varied between 2.61 and 14.0. Both parameters as well as the preload brain phenylalanine levels correlated significantly with the degree of cerebral white matter abnormalities on magnetic resonance images. Correlations of K(t,app), Tmax/Vmet, and the preload brain phenylalanine levels with patients' intelligence scores approached significance. In conclusion, blood-brain barrier phenylalanine transport characteristics and the resultant brain phenylalanine levels seem to be causative factors for the individual clinical outcome in phenylketonuria. This observation may lead to individual dietary recommendations in the future.

Adolescent↗

[Quality management in postoperative pain therapy].

BACKGROUND: Deficits in quality of postoperative pain management are not caused by the complexity of the medical problem or shortage of suitable drugs but by difficulties in organization and hospital structures. Moreover, there is no consensus on how to measure the quality of pain management. Quality management programs consist of strategies to overcome such difficulties and to increase quality continuously. This study reports the implementation of a quality management program to improve postoperative pain management at a university hospital. METHODS: An interdisciplinary task force consisting of nursing staff, anesthesiologists, surgeons, and members of the hospital pharmacy was set up. This task force interviewed patients and performed an analysis of current deficits (phase 1). Then, primary and secondary outcome parameters were defined to measure quality of pain management, and strategies were defined to implement improvements (phase 2). These referred to aspects of organization, standardization, and responsibility. One of the main intentions was the involvement of nursing staff. After implementation (phase 3), a second analysis was performed (phase 4). This was followed by a continuous assessment of parameters indicating quality of procedures and results which were fed back to all participants (phase 5). RESULTS: After implementation of the program (phase 4), significantly more patients reported no or mild (NRS < 4) postoperative pain (40.2% vs 30.1%) compared to phase 1. Also, patients' satisfaction with pain therapy improved significantly. The proportion of patients without pain treatment decreased by one-third. Opioids were given more frequently and more often intravenously. In contrast, the proportion of i.m. injections decreased from 20% to 5%. Continuous assessment of up to now more than 4,900 patients helped to identify possible reasons for problems and to maintain overall quality of pain management. DISCUSSION: Tools of quality management consisting of deficit analysis, definition of outcome parameters, implementation of improving strategies, post-intervention analysis and continuous feed-back may be successfully used to improve postoperative pain therapy. Changes in organization of medical management seem to be more important than medical or technical aspects. Similar strategies might be used to increase quality of other medical procedures.

Analgesics, Opioid↗