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Membrane microdialysis: Evaluation of a new method to assess splanchnic tissue metabolism*

Authors :
Hendrik Bracht
Rafael Knuesel
Stephan M. Jakob
Francesca Porta
Matthias Haenggi
Lukas Brander
Jukka Takala
Source :
Critical Care Medicine. 34:2638-2645
Publication Year :
2006
Publisher :
Ovid Technologies (Wolters Kluwer Health), 2006.

Abstract

OBJECTIVE: Measuring peritoneal lactate concentrations could be useful for detecting splanchnic hypoperfusion. The aims of this study were to evaluate the properties of a new membrane-based microdialyzer in vitro and to assess the ability of the dialyzer to detect a clinically relevant decrease in splanchnic blood flow in vivo. DESIGN: A membrane-based microdialyzer was first validated in vitro. The same device was tested afterward in a randomized, controlled animal experiment. SETTING: University experimental research laboratory. SUBJECTS: Twenty-four Landrace pigs of both genders. INTERVENTIONS: In vitro: Membrane microdialyzers were kept in warmed sodium lactate baths with lactate concentrations between 2 and 8 mmol/L for 10-120 mins, and microdialysis lactate concentrations were measured repeatedly (210 measurements). In vivo: An extracorporeal shunt with blood reservoir and roller pump was inserted between the proximal and distal abdominal aorta, and a microdialyzer was inserted intraperitoneally. In 12 animals, total splanchnic blood flow (measured by transit time ultrasound) was reduced by a median 43% (range, 13% to 72%) by activating the shunt; 12 animals served as controls. MEASUREMENTS AND MAIN RESULTS: In vitro: The fractional lactate recovery was 0.59 (0.32-0.83) after 60 mins and 0.82 (0.71-0.87) after 90 mins, with no further increase thereafter. At 60 and 90 mins, the fractional recovery was independent of the lactate concentration. In vivo: Abdominal blood flow reduction resulted in an increase in peritoneal microdialysis lactate concentration from 1.7 (0.3-3.8) mmol/L to 2.8 (1.3-6.2) mmol/L (p = .006). At the same time, mesenteric venous-arterial lactate gradient increased from 0.1 (-0.2-0.8) mmol/L to 0.3 (-0.3 -1.8) mmol/L (p = .032), and mesenteric venous-arterial Pco2 gradients increased from 12 (8-19) torr to 21 (11-54) torr (p = .005). CONCLUSIONS: Peritoneal membrane microdialysis provides a method for the assessment of splanchnic ischemia, with potential for clinical application.

Details

ISSN :
00903493
Volume :
34
Database :
OpenAIRE
Journal :
Critical Care Medicine
Accession number :
edsair.doi...........5cc3bd0933a01fd737ef689d15ea1647
Full Text :
https://doi.org/10.1097/01.ccm.0000239430.73826.23