Quantitative Erfassung der Katecholaminsekretion als rationale Grundlage des Anästhesiemanagements bei Phäochromozytomexstirpation

Schüttler, J.; Westhofen, P.; Kania, U.; Ihmsen, Harald; Kammerecker, S.; Hirner, A.

doi:10.1055/s-2007-996507

Cited by 21 publications

(9 citation statements)

References 5 publications

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“…In sporadic EPI-secreting pheochromocytomas the average EPI content was about 3,801,000 pg/g tissue, with about 5% of its release each day (Eisenhofer, unpublished observations). At such levels, any direct tumor stimulation may lead to abrupt and significant catecholamine release that exceed normal plasma values 1,000 times or more with devastating consequences, often presenting as an emergency ( Table 3 ) (80-82). These differences in catecholamine content and release as well as their action on adrenoceptors explain different clinical presentations and ultimately necessitate specific treatment for each patient.…”

Section: Pheochromocytoma: a Catecholamine Disordermentioning

confidence: 99%

Phaeochromocytoma: a catecholamine and oxidative stress disorder

Pacák¹

2011

endo

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The WHO classification of endocrine tumors defines pheochromocytoma as a tumor arising from chromaffin cells in the adrenal medulla — an intra-adrenal paraganglioma. Closely related tumors of extra-adrenal sympathetic and parasympathetic paraganglia are classified as extra-adrenal paragangliomas. Almost all pheochromocytomas and paragangliomas produce catecholamines. The concentrations of catecholamines in pheochromocytoma tissues are enormous, potentially creating a volcano that can erupt at any time. Significant eruptions result in catecholamine storms called “attacks” or “spells”. Acute catecholamine crisis can strike unexpectedly, leaving traumatic memories of acute medical disaster that champions any intensive care unit. A very well-defined genotype-biochemical phenotype relationship exists, guiding proper and cost-effective genetic testing of patients with these tumors. Currently, the production of norepinephrine and epinephrine is optimally assessed by the measurement of their O-methylated metabolites, normetanephrine or metanephrine, respectively. Dopamine is a minor component, but some paragangliomas produce only this catecholamine or this together with norepinephrine. Methoxytyramine, the O-methylated metabolite of dopamine, is the best biochemical marker of these tumors. In those patients with equivocal biochemical results, a modified clonidine suppression test coupled with the measurement of plasma normetanephrine has recently been introduced. In addition to differences in catecholamine enzyme expression, the presence of either constitutive or regulated secretory pathways contributes further to the very unique mutation-dependent catecholamine production and release, resulting in various clinical presentations. Oxidative stress results from a significant imbalance between levels of prooxidants, generated during oxidative phosphorylation, and antioxidants. The gradual accumulation of prooxidants due to metabolic oxidative stress results in proto-oncogene activation, tumor suppressor gene inactivation, DNA damage, and genomic instability. Since the mitochondria serves as the main source of prooxidants, any mitochondrial impairment leads to severe oxidative stress, a major outcome of which is tumor development. In terms of cancer pathogenesis, pheochromocytomas and paragangliomas represent tumors where the oxidative phosphorylation defect due to the mutation of succinate dehydrogenase is the cause, not a consequence, of tumor development. Any succinate dehydrogenase pathogenic mutation results in the shift from oxidative phosphorylation to aerobic glycolysis in the cytoplasm (also called anaerobic glycolysis if hypoxia is the main cause of such a shift). This phenomenon, also called the Warburg effect, is well demonstrated by a positive [18F]-fluorodeoxyglycose positron emission tomography scan. Microarray studies, genome-wide association studies, proteomics and protein arrays, metabolomics, transcriptomics, and bioinformatics approaches will remain powerful tools to further uncover the pathogenesis of t...

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Section: Pheochromocytoma: a Catecholamine Disordermentioning

confidence: 99%

Phaeochromocytoma: a catecholamine and oxidative stress disorder

Pacák¹

2011

endo

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“…Weiter führen prä-und intraoperative Streßsituationen, vor allem jedoch Manipulationen am Tumor zur Sekretion großer Mengen von Katecholaminen mit der Gefahr hypertensiver Krisen [12], welche durch invasives Monitoring rasch erkannt werden kön-nen. …”

Section: Phäochromozytome Kommen Beimunclassified

“…Während die meisten Autoren eine alpha-Rezeptorenblockade mit Phenoxybenzamin unter differenzierter Volumentherapie empfehlen [5,7,10,12,13], befürworten andere die alpha-Blockade mit Prazosin und den Einsatz von Phenoxybenzamin nur bei hypertensiven Krisen [1,9]. Die Gruppe um Bravo empfiehlt, möglichst auf eine präopera-tive alpha-Blockade zu verzichten [3,4,6].…”

Section: Der Anaesthesist 9·97unclassified

Intraoperative Diagnose eines multilokulären Phäochromozytoms

et al. 1997

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Pheochromocytomas are functionally active, catecholamine-secreting tumours of chromaffin tissue. The mainstay of pharmacological therapy is preoperative treatment with oral phenoxybenzamine. This drug irreversibly alkylates alpha-1-adrenergic receptors on vascular smooth muscle and renders them nonfunctional, thereby causing vasodilatation. The duration of action of a single dose is approximately 24 h. Therefore, postoperative hypotension is a hazard of therapy with phenoxybenzamine if adequate plasma volume repletion is not provided. Prazosin, a short-acting, competitive alpha-1 blocker, has been used preoperatively, but has been criticized for its failure to adequately prevent perioperative hypertensive episodes. We report the case of a 73-year-old woman who was admitted for elective pheochromocytoma resection. Preoperative therapy with phenoxybenzamine was impossible because of the patient's refusal to take the drug. Preoperative antihypertensive preparation was therefore performed with prazosin 30 mg/24 h and metoprolol 100 mg/24 h. During the surgical preparation of the tumor, sodium nitroprusside was started at an average infusion rate of 4.1 micrograms/kg/min. After resection of the primary tumor, when the sodium nitroprusside infusion was stopped the patient exhibited an increase in systolic blood pressure (BP) up to 210 mg Hg. This hypertensive crisis was managed with sodium nitroprusside, nitroglycerin, and esmolol. A multilocular pheochromocytoma was diagnosed. Further stimuli due to tumour palpation resulted in repeated increases in BP. In this manner, two additional areas of tumour could be diagnosed by BP peaks after reduction of the sodium nitroprusside infusion. After complete resection of a total of three tumours, no further hypertensive crises occurred. The patient's postoperative course was uneventful. We conclude that in this patient presenting with an unsuspected multilocular pheochromocytoma, the lack of permanent alpha-blockade was probably helpful in allowing complete resection of all the tumours.

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“…Often, these tumours can erupt without a trigger. The above scenarios, including direct PHAEO/PGL manipulation, can lead to significant catecholamine release exceeding normal plasma values 1000 times or greater 5 . Furthermore, approximately 20% of patients do not present with hypertension due to downregulation of adrenoceptors resulting from prolonged elevation of circulating catecholamines.…”

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confidence: 99%