Abstract:

Objective To evaluate the correlation between partial CO₂rebreathing method and transesophageal doppler for cardiac output monitoring during controlled hypotension induced by sodium nitroprusside(SNP) in neurosurgical patients. Methods Twenty-five ASA Ⅰ～Ⅱ patients (11 male, 14 female), aged 19～55 years, undergoing elective neurosurgery were enrolled in this study. Anesthesia was maintained with 1.0 MACisoflurane. Controlled hypotension was performed after opening of dura with continuous infusion of SNP. Simultaneous measurements of cardiac output(CO) with partial CO₂rebreathing method(RBCO) and transesophageal doppler(TECO) were performed in 25 neurosurgical patients. Results CO and HR increased during controlled hypotension. Agood correlation was found between RBCOand TDCO(r=0.76, P<0.01), regression equation was RBCO=0.86 TECO+0.59, with a basid calculation of -0.61 L/min. Conclusion There are good correlation between two methods. Partial CO₂ rebreathing method and transesophageal doppler technique are good measurement hemodynamics for monitoring changes of COin neurosurgical patients.

Key words: CO₂, doppler, cardiac output, neurosurgical operation, controlled hypotension