Relationship between Anesthetic Depth and Venous Oxygen Saturation during Cardiopulmonary Bypass

Background During cardiopulmonary bypass, mixed venous oxygen saturation (Svo2) is frequently measured to assess circulatory adequacy. Fluctuations in Svo2 not related to patient movement or inadequate oxygen delivery have been attributed clinically to increased cerebral oxygen consumption due to "light" anesthesia. To evaluate the relationship between anesthetic depth and Svo2, we prospectively measured bispectral index (BIS) and Svo2 values in patients undergoing cardiac surgery with cardiopulmonary bypass. Methods Adults scheduled for cardiac surgery with cardiopulmonary bypass were recruited for this prospective observational study. During bypass, BIS and Svo2 values were recorded every 5 min. To control for confounding effects of changes in other variables known to affect Svo2, temperature, hematocrit, bypass pump flow, muscle relaxant use, and intravenous and inhaled anesthetic doses were also recorded. Only periods with limited variation in other variables affecting Svo2 were analyzed. The relationship between BIS and Svo2 was evaluated using mixed linear regression. Results One thousand thirty-four data points were obtained in 41 patients. No overall association between BIS and Svo2 was observed, either in unadjusted analysis or adjusted for covariates. In data points with temperatures less than the median (T < 34.1 degrees C), a significant association between BIS and Svo2 was observed both in unadjusted (beta = -0.32, P = 0.01) and adjusted (beta = -0.27, P = 0.04) analyses. Conclusions In patients undergoing cardiopulmonary bypass, we found no overall association between BIS and Svo2. A weak but statistically significant association between BIS and Svo2 was observed in patients with temperatures less than 34.1 degrees C. These data suggest that low Svo2 values on bypass are unlikely to be due to light or inadequate anesthesia. The relationship among temperature, BIS and Svo2 deserves further study.

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Remimazolam anesthesia for cardiac surgery with cardiopulmonary bypass: a case report

JA Clinical Reports ◽

10.1186/s40981-021-00424-0 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Kota Saito ◽

Sho Ohno ◽

Makishi Maeda ◽

Naoyuki Hirata ◽

Michiaki Yamakage

Keyword(s):

Cardiac Surgery ◽

Cardiopulmonary Bypass ◽

Oxygen Saturation ◽

Anesthetic Management ◽

Perioperative Period ◽

Maze Procedure ◽

Intraoperative Awareness ◽

Case Presentation ◽

Venous Oxygen Saturation ◽

Index Value

Abstract Background Remimazolam has less cardiovascular depressant effects than propofol in non-cardiac surgical patients. However, the efficacy and safety of remimazolam in cardiac surgery with cardiopulmonary bypass (CPB) have not been reported. We present a case of successful anesthetic management using remimazolam in cardiac surgery with CPB. Case presentation A 76-year-old female was scheduled for mitral valve repair, tricuspid annuloplasty, maze procedure, and left atrial appendage closure. We used remimazolam in induction (6.0 mg/kg/h) and maintenance (0.6–1.0 mg/kg/h) of general anesthesia, and the bispectral index value was maintained in the range of 36 to 48 including the period of CPB. Hemodynamics, mixed venous oxygen saturation, and bilateral regional cerebral oxygen saturation were maintained within acceptable ranges. There was no intraoperative awareness/recall or serious complications associated with remimazolam throughout the perioperative period. Conclusions Remimazolam can be used the same as other existing anesthetics in cardiac surgery with CPB.

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The relationship between mixed venous and regional venous oxygen saturation during cardiopulmonary bypass

Perfusion ◽

10.1191/0267659102pf545oa ◽

2002 ◽

Vol 17 (2) ◽

pp. 133-139 ◽

Cited By ~ 12

Author(s):

Lena Lindholm ◽

Vigdis Hansdottir ◽

Magnus Lundqvist ◽

Anders Jeppsson

Keyword(s):

Cardiopulmonary Bypass ◽

Oxygen Saturation ◽

Hepatic Vein ◽

Jugular Vein ◽

Venous Blood ◽

Mixed Venous Blood ◽

Mixed Venous Saturation ◽

Venous Oxygen Saturation ◽

The Relationship ◽

Mixed Venous

The relationship between mixed venous and regional venous saturation during cardiopulmonary bypass (CPB), and whether this relationship is influenced by temperature, has been incompletely elucidated. Thirty patients undergoing valve and/or coronary surgery were included in a prospective, controlled and randomized study. The patients were allocated to two groups: a hypothermic group (28°C) and a tepid group (34°C). Blood gases were analysed in blood from the hepatic vein and the jugular vein and from mixed venous blood collected before surgery, during hypothermia, during rewarming, and 30 min after CPB was discontinued. Oxygen saturation in the hepatic vein was lower than in the mixed venous blood at all times of measurement (-24.0 ± 3.0% during hypothermia, -36.5 ± 2.9% during rewarming, and -30.5 ± 3.0% postoperatively, p < 0.001 at all time points). In 23% of the measurements, the hepatic saturation was < 25% in spite of normal (> 60%) mixed venous saturation. There was a statistical correlation between mixed venous and hepatic vein oxygen saturation (r = 0.76, p < 0.0001). Jugular vein oxygen saturation was lower than mixed venous saturation in all three measurements (-21.6 ± 1.9% during hypothermia, p < 0.001; -16.7 ± 1.9% during rewarming, p < 0.001; and -5.6 ± 2.2% postoperatively, p = 0.037). No significant correlation in oxygen saturation could be detected between mixed venous and jugular vein blood ( r = 0.06, p = 0.65). Systemic temperature did not influence the differences in oxygen saturation between mixed venous and regional venous blood at any time point. In conclusion, regional deoxyge-nation occurs during CPB, in spite of normal mixed venous saturation. Mixed venous oxygen saturation correlates with hepatic, but not with jugular, vein saturation. The level of hypothermia does not influence differences in oxygen saturation between mixed venous and regional venous blood.

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