Simplified dual-lumen catheter design for simultaneous potentiometric monitoring of carbon dioxide and pH
| Autor: | Michael E. Collison, Mark E. Meyerhoff, Martin Telting-Diaz |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Chemistry
Potentiometric titration Analytical chemistry Plasticizer Ionophore Partial pressure Electrolyte Carbon Dioxide Hydrogen-Ion Concentration Silicone rubber Reference electrode Analytical Chemistry chemistry.chemical_compound Catheters Indwelling Dogs Electrode Calibration Animals Cattle Blood Gas Analysis |
| Zdroj: | Analytical chemistry. 66(4) |
| ISSN: | 0003-2700 |
| Popis: | A novel dual-lumen catheter electrode design suitable for the simultaneous measurement of PCO2 (partial pressure of carbon dioxide) and pH in flowing blood is described. The probe is fabricated from a single segment of dual-lumen silicone rubber or polyurethane tubing that is impregnated with the proton ionophore tridodecylamine. The impregnation step imparts H+ permselectivity to both inner and outer walls of the tubing. By filling each lumen with a suitable buffer/electrolyte solution and Ag/AgCl reference electrode wire, simultaneous potentiometric detection of both PCO2 and pH is achieved. Careful optimization of incorporated proton carrier (tridodecylamine), plasticizer (o-nitrophenyl octyl ether), and lipophilic counteranion sites (tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) within the tubing walls yields catheter electrodes with resistance values of 10-20 M omega and relatively high stability in flowing blood. Results from continuous measurements of PCO2 and pH during long-term 30-65-h blood loop experiments demonstrate that, after an initial conditioning period, the catheter exhibits low drift rates (PCO2, 4.7 +/- 1.7 mV/30 h; pH, 1.4 +/- 0.5 mV/30 h) and yields continuously measured values in good agreement with those obtained on discrete samples with a commercial blood gas analyzer (PCO2, r2 = 0.997; pH, r2 = 0.915). In vivo evaluation of the catheter sensors, performed by implanting silicone rubber dual-lumen probes in the arteries of anesthetized dogs, indicates that the proposed catheter design can closely follow PCO2/pH changes induced in the animals during 6-13 h of continuous monitoring. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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