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Published on: December 17, 2014
Cerebrovascular carbon dioxide reactivity with propofol anesthesia in patients with previous stroke
Hiroshi Hinohara1, Yuji Kadoi, Ken-ichiro Takahashi
1Department of Intensive Care, Gunma University, Graduate School of Medicine, Gunma, Japan.
Study Objective:
To examine whether patients with previous stroke have impaired cerebrovascular carbon dioxide (CO2) reactivity when receiving propofol anesthesia.
Design:
Prospective, controlled study.
Setting:
University hospital.
Patients:
34 consecutive patients, 17 of whom had previous stroke and were scheduled for elective cardiac surgery, and 17 control age-matched patients without previous stroke who were also scheduled for cardiac surgery.
Interventions:
Anesthesia was induced and a 2.5-MHz pulsed transcranial Doppler probe was attached to the patient's head at the right temporal window. Mean blood flow velocity of the middle cerebral artery (Vmca) was measured continuously.
Measurements:
After establishing baseline Vmca, arterial blood gases and cardiovascular hemodynamic values, partial pressure of end-tidal CO2 (PETCO2) was increased by changing the ventilatory frequency by 2 to 5 breaths/min. The measurements were repeated when PETCO2 increased and remained stable for 5 to 10 minutes.
Main Results:
Values for absolute CO2 reactivity in the control patients and in those with previous stroke were 2.6 +/- 0.5 and 2.9 +/- 0.7 cm/sec/mmHg, respectively, a nonsignificant difference in these values. Values for relative CO2 reactivity in control patients and in patients with previous stroke were 6.4 +/- 1.4 and 6.1 +/- 1.4%/mmHg, respectively, with no significant difference noted.
Conclusions:
Cerebrovascular CO2 reactivity in patients with previous stroke is normal during propofol anesthesia.
