Monitoring the Oxygen Reserve Index can contribute to the early detection of deterioration in blood oxygenation during one-lung ventilation.

BACKGROUND: Hypoxemia can occur during one-lung ventilation (OLV), but monitoring blood oxygenation using percutaneous oxygen saturation (SpO2) can be limited by detection latency, and SpO2 sometimes does not change during OLV. The Oxygen Reserve Index (ORi™) is a novel index reported to detect impending desaturation before this is observed with SpO2 monitoring. This study assessed whether the ORi decreased earlier than SpO2 during OLV and evaluated its correlation with the partial pressure of arterial oxygen (PaO2) during OLV. METHODS: The study enrolled 15 patients undergoing elective thoracic surgery. The patient's trachea was intubated with a left-sided double-lumen endotracheal tube and the lungs were mechanically ventilated in pressure-control mode for 10 min, with the fraction of inspired oxygen set at 0.6. Right OLV was then initiated for 15 min or until SpO2 declined to 91%, while continuously recording the ORi and SpO2. PaO2 was measured 5 min before and every 3 min during OLV. Mean (SD) times from the start of OLV to the start of the decreases in ORi and SpO2 were calculated. RESULTS: ORi started decreasing significantly before SpO2 (ORi vs. SpO2: 171 [102] vs. 372 [231] s; P<0.01). ORi showed a significant, strong correlation with PaO2 (r2=0.671, P<0.01). CONCLUSIONS: ORi decreased earlier than SpO2 during OLV. This index could contribute to the early detection of deterioration in blood oxygenation during OLV.

Perioperative management of a pregnant patient with mediastinal tumor complicated by tuberculosis.

Mediastinal tumor in a pregnant woman, which had needed a multidisciplinary approach, was further complicated by tuberculosis. The clinical course of the current patient was very complicated. A 37-year-old female at 18 weeks of gestation with a mediastinal tumor was referred to our hospital due to dyspnea and orthopnea. The tumor compressed the left main bronchus causing bronchial stenosis. She was diagnosed with primary mediastinal large B-cell non-Hodgkin's lymphoma. Delivery after 24 gestational weeks with ongoing chemotherapy was planned by a multidisciplinary team comprising obstetricians, anesthesiologists, neonatologists, and hematologists. Her symptoms improved with chemotherapy; however, she was later diagnosed with tuberculosis leading to chemotherapy interruption to treat tuberculosis. The following confirmation by negative sputum smear microscopy, an elective cesarean section with spinal anesthesia was performed at 33 weeks of gestation, and she safely delivered a female infant. At postoperative day 23, she died due to cardiopulmonary arrest, following an irreversible coma subsequent to brain metastasis of malignant lymphoma. The infant died of respiratory failure at postoperative day 18. This case illustrates several implications, such as the necessity of a thorough systemic examination and treatment approaches for mothers and neonates with suspected tuberculosis during the perioperative period, for considering similar cases with neoplasms.