The effect of hypercapnia and hypertension on cerebral oxygen balance during one-lung ventilation for lung surgery during propofol anesthesia.
ABSTRACT To investigate whether jugular bulb venous oxygen saturation (SjO(2)) values increased with induced hypercapnia or induced hypertension during propofol-based anesthesia for one-lung ventilation (OLV).
Prospective clinical study.
Operating room at University hospital.
15 adult patients scheduled for elective thoracic procedures in the lateral position.
General anesthesia was maintained with propofol combined with epidural anesthesia. During OLV, hypercapnia (PaCO(2) = 50 mmHg) and hypertension (20% increase in mean arterial pressure) were applied.
SjO2 values were measured.
With hypercapnia, SjO(2) values increased 30 ± 18% (from 54.3 ± 8.8% to 69.3 ± 6.3%). With hypertension, SjO(2) values were increased by 9 ± 18% (from 54.4 ± 9.0% to 58.5 ± 8.8%). These changes were significantly different. No significant differences regarding SaO(2) were observed during OLV in the experimental period.
Hypercapnia, not hypertension, significantly improved cerebral oxygen balance without observed side effects during propofol anesthesia.
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ABSTRACT: Tissue oxygenation is the primary determinant of wound infection risk. Mild hypercapnia markedly improves cutaneous, subcutaneous (s.c.), and muscular tissue oxygenation in volunteers and patients. However, relative contributions of increased cardiac output and peripheral vasodilation to this response remains unknown. We thus tested the hypothesis that increased cardiac output is the dominant mechanism. We recruited 10 ASA III patients, aged 40-65 yr, undergoing cardiopulmonary bypass for this crossover trial. After induction of anaesthesia, a Silastic tonometer was inserted s.c. in the upper arm. S.C. tissue oxygen tension was measured with both polarographic electrode and fluorescence-based systems. Oximeter probes were placed bilaterally on the forehead to monitor cerebral oxygenation. After initiation of cardiopulmonary bypass, in random order patients were exposed to two arterial CO(2) partial pressures for 30 min each: 35 (normocapnia) or 50 mm Hg (hypercapnia). Bypass pump flow was kept constant throughout the measurement periods. Hypercapnia during bypass had essentially no effect on Pa(CO(2)) , mean arterial pressure, or tissue temperature. Pa(CO(2)) and pH differed significantly. S.C. tissue oxygenation was virtually identical during the two Pa(CO(2)) periods [139 (50-163) vs 145 (38-158), P=0.335] [median (range)]. In contrast, cerebral oxygen saturation (our positive control measurement) was significantly less during normocapnia [57 (28-67)%] than hypercapnia [64 (37-89)%, P=0.025]. Mild hypercapnia, which normally markedly increases tissue oxygenation, did not do so during cardiopulmonary bypass with fixed pump output. This suggests that hypercapnia normally increases tissue oxygenation by increasing cardiac output rather than direct dilation of peripheral vessels.BJA British Journal of Anaesthesia 07/2006; 96(6):708-14. · 4.35 Impact Factor
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ABSTRACT: During one-lung ventilation (OLV), systemic oxygenation can be compromised. In such a scenario, if anesthetic techniques were used that adversely affected cerebral oxygen balance, the risk for impaired cerebral oxygen balance may be increased. In this study, jugular bulb venous oxygen saturation (SjO(2)) during OLV under sevoflurane- or propofol-based anesthesia for lung surgery was investigated. Prospective clinical study. University hospital. Fifty-two adult patients scheduled for elective thoracic procedures in the lateral position. Patients were randomly allocated to either the sevoflurane or propofol group (n = 26). General anesthesia was maintained with sevoflurane or propofol combined with epidural anesthesia. Arterial and jugular bulb blood samples were measured before OLV, 15 minutes after OLV, 30 minutes after OLV, and 15 minutes after the termination of OLV. SjO(2) values in both sevoflurane and propofol groups significantly declined during OLV (p < 0.05). SjO(2) values in the sevoflurane group were higher than in the propofol group, although SaO(2) values were similar (p < 0.05). Regarding the incidence of SjO(2) <50% (cerebral oxygen desaturation), there were significant differences between the sevoflurane group and the propofol group during both normally ventilated conditions (0% v 7.7%, p < 0.05, relative risk [RR]: not applicable) and OLV (1.9% v 26.9%, p < 0.05, RR = 14; 95% confidence interval [CI] 1.91-103). Significant increase in the incidence of SjO(2) <50% during OLV was also observed only in the propofol group (from 7.7% to 26.9%, p < 0.05, RR = 3.5; 95% CI 1.29-12.4). Cerebral oxygen desaturation was more frequently detected during OLV under propofol- versus sevoflurane-based anesthesia. Cerebral oxygen balance during OLV for lung surgery was less impaired under sevoflurane-based anesthesia compared with propofol; however, the clinical outcome or implications for cognitive function need to be determined.Journal of cardiothoracic and vascular anesthesia 02/2008; 22(1):71-6. · 1.06 Impact Factor
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ABSTRACT: We undertook surgical bilateral lung volume reduction in 20 patients with severe chronic obstructive pulmonary disease to relieve thoracic distention and improve respiratory mechanics. The operation, done through median sternotomy, involves excision of 20% to 30% of the volume of each lung. The most affected portions are excised with the use of a linear stapling device fitted with strips of bovine pericardium attached to both the anvil and the cartridge to buttress the staple lines and eliminate air leakage through the staple holes. Preoperative and postoperative assessment of results has included grading of dyspnea and quality of life, exercise performance, and objective measurements of lung function by spirometry and plethysmography. There has been no early or late mortality and no requirement for immediate postoperative ventilatory assistance. Follow-up ranges from 1 to 15 months (mean 6.4 months). The mean forced expiratory volume in 1 second has improved by 82% and the reduction in total lung capacity, residual volume, and trapped gas has been highly significant. These changes have been associated with marked relief of dyspnea and improvement in exercise tolerance and quality of life. Although the follow-up period is short, these preliminary results suggest that bilateral surgical volume reduction may be of significant value for selected patients with severe chronic obstructive pulmonary disease.Journal of Thoracic and Cardiovascular Surgery 02/1995; 109(1):106-16; discussion 116-9. · 3.99 Impact Factor