Journal of cardiothoracic anesthesia
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J Cardiothorac Anesth · Dec 1988
Influence of high-dose opioid anesthesia on posterior tibial nerve somatosensory cortical evoked potentials: effects of fentanyl, sufentanil, and alfentanil.
The effects of high doses of fentanyl (group F), sufentanil (group S), and alfentanil (group A) on posterior tibial nerve somatosensory cortical evoked potentials were studied in 30 patients scheduled for elective valve replacement surgery. Anesthesia was induced with either fentanyl, 75 microg/kg, sufentanil, 5 microg/kg, or alfentanil, 125 microg/kg. The lungs were ventilated with oxygen/air. ⋯ A bolus dose of fentanyl, 25 microg/kg, given in group F at 30 minutes after induction of anesthesia did not change latencies and amplitudes. No significant differences in latency or amplitude were found at any time among the three study groups. It is concluded that anesthesia with high doses of fentanyl, sufentanil, or alfentanil is a suitable technique when intraoperative monitoring of posterior tibial nerve somatosensory cortical evoked potentials is indicated.
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J Cardiothorac Anesth · Dec 1988
Randomized Controlled TrialInfluence of acute preoperative hemodilution on right ventricular function.
In a randomized study, the effects of acute, preoperative hemodilution (HD) (12 mL/kg) on right ventricular function were investigated in coronary artery surgery patients with reduced left ventricular function (ejection fraction < 50%) and significant stenosis of the right coronary artery (RCA). Blood was replaced either by hydroxyethyl starch (HES) solution (ratio 1:1; HD-HES; n = 15) or by Ringer's lactate, (RL) (ratio 2.5:1; HD-RL; n = 15). Fifteen comparable patients without HD served as a control group. ⋯ Furthermore, right ventricular function of the hemodiluted patients was not impaired by the subsequent ECC procedure. None of the traditionally measured parameters could be correlated significantly to the right ventricular thermodilution variables. It is concluded that moderate HD does not change right ventricular function even when the RCA is significantly stenosed.
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J Cardiothorac Anesth · Dec 1988
Continuous low-flow supracarinal and subcarinal oxygen insufflation in addition to intermittent positive-pressure ventilation does not improve gas exchange.
Recent studies in animals have demonstrated that continuous insufflation of oxygen near the tracheal carina results in ventilation and carbon dioxide removal that is proportional to the flow rate. The purpose of this study was to determine whether the addition of supracarinal and subcarinal low-flow oxygen insufflation to conventional intermittent positive-pressure ventilation (IPPV) of critically ill and anesthetized patients results in increased ventilation and improved oxygenation. In eight studies a supracarinal catheter (3.7 mm OD) was placed 1 to 2 cm above the carina, and in another eight studies two subcarinal catheters (1.7 mm OD) were placed 2 cm below the tracheal carina under direct vision with a fiberoptic bronchoscope. ⋯ Conversely, there was a significant decrease in mean arterial pressure and cardiac output with each incremental increase in continuous oxygen flow rate. It is concluded that use of continuous low-flow insufflation of oxygen with simple administration systems (catheters within the lumen of endotracheal tube) in addition to conventional IPPV is contraindicated at the present time. Further studies using different insufflation systems may prove to be worthwhile.
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J Cardiothorac Anesth · Dec 1988
Editorial CommentImproving the design and function of double-lumen tubes.