Continuous contralateral jugular acid-base and blood gas monitoring during carotid endarterectomy.

BACKGROUND: The aim of this study is to evaluate the intravascular multiparameter sensor Paratrend 7 (P7) for continuous acid-base and blood gas monitoring after retrograde jugular catheterization during carotid endarterectomy. PATIENTS AND METHODS: We studied 11 patients with history of smoking (72.7%), coronary artery disease (72.7%), hypertension (100%), diabetes mellitus (55.5%) and TIA's and/or nondisabling stroke (90.9%). The contralateral internal jugular vein was punctured retrogradely and the calibrated P7 sensor was introduced. The sensor was removed after surgery. The P7 provides continuous graphical display of pH, pCO2, and pO2, while temperature, oxygen saturation, HCO3 concentration and base excess are displayed numerically. RESULTS: Mean duration of carotid cross-clamping was 17.0 +/- 6.2 min. Mean stump pressure was 50.2 +/- 12.9 mmHg. Intraluminal shunting was not used in any operation. All sensors were easily inserted. During clamping, pH became persistently more acidic (7.31 to 7.28; p < 0.05), pCO2 was elevated (44.7 to 49.8 mmHg; p < 0.05) while, in the majority of the patients, there was a non significant decrease in pjvO2/SjvO2. Declamping was followed by a short period of decrease of pH and elevation of pCO2 reminiscent of wash out phenomena. PjvO2 was significantly elevated (53.8 +/- 5.2 to 59.0 +/- 5.8 mmHg; p < 0.001) after the restoration of flow. In one case, P7 was diagnostic for unsuccessful endarterectomy. CONCLUSIONS: P7 is useful during carotid endarterectomy providing continuous and "on-line" information on brain metabolism. It is a simple and powerful technique, which should be further investigated.