Neuropediatrics 2005; 36 - P25
DOI: 10.1055/s-2005-868010

Subcutaneous microdialysis – a safe and minimal-invasive method for biochemical tissue monitoring in mitochondrial diseases

A Hack 1, V Busch 1, B Pascher 1, K Gempel 2, FAM Baumeister 1
  • 1Kinderklinik und Poliklinik der Technischen Universität München, Kinderklinik Schwabing, Neuropädiatrie, München
  • 2Akademisches Lehrkrankenhaus München Schwabing, Institut für Klinische Chemie, Molekulare Diagnostik und Mitochondriale Genetik, München

Mitochondrial diseases (MitDi) usually result in increased lactate levels. Determining lactate in the blood can be adulterated due to sampling, numerous blood checks are cumbering for children.

Subcutaneous microdialysis (sc MD) is a sampling method that permits continuous analysing a patients extracellular tissue chemistry without draining blood.

Objectives: Prospective Detection of side effects related to sc MD for biochemical monitoring (lactate acidosis and/or hypoglycaemia).

Material and Methods: 48 sc MD catheters were inserted into 42 patients: 28 infants, 13 children <6 y, and 7 children >6 y; 19 of them to monitor their energy metabolism (Lac, Pyr, Glu) due liable or definite MitDi, 20 because of hypoglycaemia. Sc MD was performed for a median (range) duration of 7 (2–16) days. We developed a minimally traumatizing insertion technique of the MD catheter into the sc tissue (Pediatrics 2001; 108:1187–92). The dialysate was analysed enzymatic and with Tandem-Masspectrometry.

Results: When sc MD catheters were inserted, a venous puncture occured to 6% (3/48), minor bleeding to 27% (13/48), and in spite of locally performed anaesthesia (EMLA) the insertion was painful for 40%(19/48).

Over the course of sc MD complications were rare: disturbtion of perfusion flow 4% (2/48), catheter dislocation 4% (2/48), bleeding around the catheter 4% (2/48). No systemic or local inflammatory reaction attributable to MD was observed in any of the patients, as well as local incompatibility. When the MD catheters were withdrawn, all of them were complete and none of the children developed a scar.

Sc MD was nearly non-problematic for the little patients. Due to repeated measurements of the metabolites, sc MD allowed the generating of diurnal profiles. In some cases (respiratory chain defect, PDH-Deficiency), with the great amount of values under standardized conditions, the significant effects of ketogenic diet on the patients metabolism have been demonstrated.

Conclusions: Sc MD is a safe method, well suited for biochemical monitoring in mitochondrial diseases.