[Risk factors for intraoperative hypoxemia during monopulmonary ventilation: an observational study]

Association between Oxygen Reserve index and arterial partial pressure of oxygen during one-lung ventilation: a retrospective cohort study

PURPOSE

We aimed to investigate the association between the Oxygen Reserve index (ORi) and arterial partial pressure of oxygen (PaO2) during one-lung ventilation in patients who underwent non-cardiac thoracic surgery requiring one-lung ventilation.

METHODS

This retrospective study assessed the eligibility of 578 adult patients who underwent elective non-cardiac thoracic surgery requiring one-lung ventilation at a tertiary hospital, and their electronic medical records were reviewed. The ORi monitor was used in all patients during anesthesia, and arterial blood gas analysis was routinely performed 15 min after the initiation of one-lung ventilation. The primary endpoint was the association between ORi and PaO2 which were measured simultaneously during one-lung ventilation. We also investigated the risk factors for PaO2 less than 150 mmHg during one-lung ventilation.

RESULTS

Total of 554 patient were included in the analysis. The ORi value measured 15 min after the start of one-lung ventilation was significantly associated with PaO2 in the linear regression model (r2 = 0.5752, P < 0.001), and 0.27 of the ORi value could distinguish PaO2 ≥ 150 mmHg (sensitivity 0.909, specificity 0.932). Risk factors for PaO2 < 150 mmHg during one-lung ventilation included a lower ORi, older age, higher body mass index, left-sided one-lung ventilation, and lower hemoglobin concentrations.

CONCLUSION

This study suggested that ORi could provide useful information on arterial oxygenation even during one-lung ventilation for non-cardiac thoracic surgery.

Prediction of Left Double-Lumen Tube Size by Measurement of Cricoid Cartilage Transverse Diameter by Ultrasound and CT Multi-Planar Reconstruction

Background: Currently, there is no uniform standard for selecting the left double lumen tubes (LDLT). Advantages, such as safety and convenience of the ultrasonic technology, and measurement accuracy, make it more widely applied in the clinical anesthesia, and computed tomography (CT) multi-planar reconstruction (MPR) technology will certainly provide a more accurate measurement. For better application for thoracic surgery choice LDLT, relieving the injury to patients, and reducing the complications, this study will compare the two approaches. Methods: The first part, 120 cases of patients were selected according to the height and gender; recording the patient's optimum LDLT and measurement the transverse diameter of the cricoid cartilage (TD-C) by ultrasound and CT MPR, and then obtained the TD-C range measurement by ultrasound and CT MPR corresponding to different types of LDLT. The second part, total of 102 patients were divided into the ultrasound group and the CT MPR group. In the ultrasound group, TD-C was measured by ultrasound, the corresponding size for intubation was selected based on the conclusions derived from the first part. In the CT MPR group, TD-C was measured by CT MPR, the corresponding size of LDLT based on the conclusions derived from the first part. Results: In the first part, 120 patients were no significant difference in the basic characteristics (P > 0.05). The accuracy of selecting the LDLT by conventional experience, namely height and gender was 58.3%. Ultrasonic measurement TD-C range was as follows: 32 Fr <15.88, 35 Fr: 15.88-16.80, 37 Fr: 16.75-17.81, and 39 Fr > 17.80. CT MPR measurement TD-C range was as follows: 32 Fr <15.74, 35 Fr: 15.74-16.65, 37 Fr: 16.56-17.68, and 39 Fr > 17.65. In the second part, there was no significant difference in the basic characteristics between the two groups (P > 0.05). The accuracy of intubation in the ultrasound group was 90.2% and the corresponding in the CT MPR group was 94.1% (P > 0.05). Conclusions: The accuracy of selecting the LDLT based on TD-C is significantly higher than conventional experience; it can significantly reduce the post-operative complications and there was no statistical significance in the accuracy of LDLT selected for TD-C measurement by ultrasound vs. CT, and both of them could be safely used for the evaluation before intubation under anesthesia in thoracic surgery.

Assessment of lung ultrasound for early detection of respiratory complications in thoracic surgery

BACKGROUND AND OBJECTIVES

To assess lung ultrasound for the diagnosis and monitoring of respiratory complications in thoracic surgery.

METHODS

Prospective observational study in a University hospital, single institution. Adult patients scheduled for pulmonary resection surgery excluding pneumonectomy. An ultrasound follow-up was performed from the day before the surgery to the third day after surgery with calculation of B-line and lung score (reaeration and loss of aeration scores). Respiratory complications were collected throughout the hospitalization period.

RESULTS

Fifty-six patients were included. Eighteen patients presented a respiratory complication (32%), and they presented significantly higher BMI and ASA scores. Patients operated by videothoracoscopy were less at risk of complications. At day 3, a reaeration score ≤ 2 on the ventilated side or ≤ -2 on the operated side, and a B-line score>6 on the operated side were in favor of a complication.

CONCLUSION

Lung ultrasound can help in the diagnosis of respiratory complications following pulmonary resection surgery.