Changes in cerebral oxygenation in patients with pulmonary dysfunction after lung resection.

Lung resection would be associated with lower jugular bulb oxygen saturation (SjvO2) values in patients with moderate to severe pulmonary dysfunction. We aimed to study the effects of lung resections on the postoperative changes in SjvO2, incidence of SjvO2 < 50%, pulmonary functions, cerebral blood flow equivalent (CBFE), and arterial to jugular difference in oxygen content (AjvDO2) in the patients with pulmonary dysfunction. Fifty-three patients scheduled for lung resection were allocated on the basis of forced vital capacity (FVC %) and forced expiratory volume in 1 second (FEV(1)%) into the following: good FVC and FEV1 (n = 14), mild (n = 14), moderate (n = 13), and severe (n = 12) pulmonary dysfunction groups. After lung resections, patients with pulmonary dysfunctions had significantly lower SjvO2, CBFE, FEV1, and FVC (P < .001), higher AjvDO2 (P < .001), and frequent episodes with SjvO2 < 50% (P < .03). Perioperative changes in FEV1 had a significant negative correlation with SjvO2 desaturation (P < .002). Patients with pulmonary dysfunction showed significant SjvO2 < 50% after lung resection, which is correlated to the perioperative changes in FEV1.

Does hypocapnia before and during carbon dioxide insufflation attenuate the hemodynamic changes during laparoscopic cholecystectomy?

BACKGROUND: Hypocapnia before and during carbon dioxide (CO(2)) insufflation for laparoscopic cholecystectomy may reduce the adverse hemodynamic responses. METHODS: After ethical approval, 100 patients scheduled for laparoscopic cholecystectomy were ventilated using a tidal volume of 8 ml/kg, an inspiration:expiration ratio of 1:2.5, and a positive end-expiratory pressure (PEEP) of 5 cm H(2)O. At 15 min before CO(2) insufflation, the patients were randomly allocated into two groups of 50 patients each. For the normocapnia group, the respiratory rate (RR) was adjusted to maintain arterial CO(2) tension (PaCO(2)) at 35 to 45 mmHg. For the hypocapnia group, the RR was adjusted to maintain PaCO(2) at 30 to 35 mmHg. Anesthesia was maintained with sevoflurane 2% to 2.5% in 40% air oxygen and rocuronium. Hemodynamic variables, PaCO(2), end-tidal CO(2) tension (EtCO(2)), arterial-to-end-tidal CO(2) (Pa-ETCO(2)) gradient, and RR were recorded. RESULTS: Compared with the control group, the use of hypocapnia before and during pneumoperitoneum was associated with significantly lower arterial blood pressures, lower PaCO(2) and EtCO(2) values, a higher Pa-ETCO(2), a higher RR (p < 0.001), and less need for supplemental doses of fentanyl and labetalol. CONCLUSION: The authors conclude that the use of hypocapnia before and during CO(2) insufflation is effective in attenuating increases in blood pressure after CO(2) pneumoperitoneum during anesthesia for laparoscopic cholecystectomy.

Effects of nondependent lung ventilation with continuous positive-pressure ventilation and high-frequency positive-pressure ventilation on right-ventricular function during 1-lung ventilation.

Background. The application of volume-controlled high frequency positive pressure ventilation (HFPPV) to the nondependent lung (NL) may have comparable effects to continuous positive airway pressure (CPAP) on the right ventricular (RV) function, oxygenation, and surgical conditions during one lung ventilation (OLV) for thoracotomy. Methods. After local ethics committee approval and informed consent, 75 patients scheduled for elective thoracotomy using OLV were randomly allocated to receive nondependent lung either CPAP 2 (CPAP2; n=25) or 5 (CPAP5; n=25) cm H2O pressure setting of the device or HFPPV using VT 3 mL-1, I: E ratio <0.3 and R.R 60/min (HFPPV; n=25), followed 15 min of OLV. Intraoperative changes in RV ejection fraction (REF), end-diastolic volume (RVEDVI) and stroke work (RVSWI), stroke volume (SVI), oxygen delivery (DO2), and uptake (VO2) indices and shunt fraction (Qs: Qt) were recorded without any surgical manipulation of the lung. Results. The application of NL-HFPPV resulted in improved REF by 33%, SVI and DO2 (P < 0.01) and reduced RVEDVI, RVSWI, PVRI, oxygen uptake, and shunt fraction by 24.8% (P < 0.01) than in the NL-CPAP groups. Conclusion. We concluded that the use of NL-HFPPV is a feasible option and offers improved RV function and oxygenation during OLV for open thoracotomy.