Pitfalls in microdialysis methodology: an in vitro analysis of temperature, pressure and catheter use.

Microdialysis of macromolecules within the brain provides a unique insight into physiological and pathological processes occurring within an otherwise inaccessible cranial cavity. The physically restricted nature of the intracranial compartment may present wider variations of pressure and temperature than those experienced in the rest of the body. In this study we attempted to determine the effect of variation of temperature and pressure on a cytokine recovery in vitro. Our results demonstrate that the wide variation of recovery attributable to different catheter use outweighed any effects caused by temperature or pressure. Investigators performing cytokine microdialysis using the CMA 71 system should be aware of the wide inter-catheter variability and potential effects of temperature on recovery.