Effects of Positive End-Expiratory Pressure on Pulmonary Oxygenation and Biventricular Function during One-Lung Ventilation: A Randomized Crossover Study

Effects of positive end-expiratory pressure on regional cerebral oxygen saturation in elderly patients undergoing thoracic surgery during one-lung ventilation: a randomized crossover-controlled trial

BACKGROUND

A significant reduction in regional cerebral oxygen saturation (rSO2) is commonly observed during one-lung ventilation (OLV), while positive end-expiratory pressure (PEEP) can improve oxygenation. We compared the effects of three different PEEP levels on rSO2, pulmonary oxygenation, and hemodynamics during OLV.

METHODS

Forty-three elderly patients who underwent thoracoscopic lobectomy were randomly assigned to one of six PEEP combinations which used a crossover design of 3 levels of PEEP-0 cmH2O, 5 cmH2O, and 10 cmH2O. The primary endpoint was rSO2 in patients receiving OLV 20 min after adjusting the PEEP. The secondary outcomes included hemodynamic and respiratory variables.

RESULTS

After exclusion, thirty-six patients (36.11% female; age range: 60-76 year) were assigned to six groups (n = 6 in each group). The rSO2 was highest at OLV(0) than at OLV(10) (difference, 2.889%; [95% CI, 0.573 to 5.204%]; p = 0.008). Arterial oxygen partial pressure (PaO2) was lowest at OLV(0) compared with OLV(5) (difference, -62.639 mmHg; [95% CI, -106.170 to -19.108 mmHg]; p = 0.005) or OLV(10) (difference, -73.389 mmHg; [95% CI, -117.852 to -28.925 mmHg]; p = 0.001), while peak airway pressure (Ppeak) was lower at OLV(0) (difference, -4.222 mmHg; [95% CI, -5.140 to -3.304 mmHg]; p < 0.001) and OLV(5) (difference, -3.139 mmHg; [95% CI, -4.110 to -2.167 mmHg]; p < 0.001) than at OLV(10).

CONCLUSIONS

PEEP with 10 cmH2O makes rSO2 decrease compared with 0 cmH2O. Applying PEEP with 5 cmH2O during OLV in elderly patients can improve oxygenation and maintain high rSO2 levels, without significantly increasing peak airway pressure compared to not using PEEP.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200060112 on 19 May 2022.

Comparison between Sugammadex and Neostigmine after Video-Assisted Thoracoscopic Surgery-Thymectomy in Patients with Myasthenia Gravis: A Single-Center Retrospective Exploratory Analysis

This single-center retrospective exploratory analysis evaluated the effects of sugammadex compared with neostigmine on postoperative recovery in patients with myasthenia gravis (MG) who underwent video-assisted thoracoscopic surgery (VATS)-thymectomy. This retrospective study included 180 patients with MG, aged >18 years, who received sugammadex (sugammadex group, n = 83) or neostigmine-glycopyrrolate (neostigmine group, n = 88) after VATS-thymectomy between November 2007 and December 2020. Inverse probability of treatment weighting (IPTW) adjustment was performed to balance the baseline characteristics between the two groups. The primary outcome was the length of postoperative hospital stay, and the secondary outcomes were the incidence of postoperative mortality and complications, as well as the postoperative extubation and reintubation rates, in the operating room after VATS-thymectomy; the outcomes were compared between the two groups. After IPTW adjustment, the sugammadex group showed a significantly shorter median postoperative hospital stay than the neostigmine group (4 (2, 4) vs. 5 (3, 6) days, respectively; p = 0.003). There were no significant differences between the two groups in the incidences of postoperative complications (including postoperative myasthenic crisis, nerve palsy, atelectasis, and pleural effusion). Patients with MG following VATS-thymectomy who received sugammadex showed a significantly shorter postoperative hospital stay than those who received neostigmine.

Effect of permissive hypercarbia on lung oxygenation during one-lung ventilation and postoperative pulmonary complications in patients undergoing thoracic surgery: A prospective randomised controlled trial

BACKGROUND

The effect of hypercarbia on lung oxygenation during thoracic surgery remains unclear.

OBJECTIVE

To investigate the effect of hypercarbia on lung oxygenation during one-lung ventilation in patients undergoing thoracic surgery and evaluate the incidence of postoperative pulmonary complications.

DESIGN

Prospective randomised controlled trial.

SETTING

A tertiary university hospital in the Republic of Korea from November 2019 to December 2020.

PATIENTS

Two hundred and ninety-seven patients with American Society of Anaesthesiologists physical status II to III, scheduled to undergo elective lung resection surgery.

INTERVENTION

Patients were randomly assigned to Group 40, 50, or 60. An autoflow ventilation mode with a lung protective ventilation strategy was applied to all patients. Respiratory rate was adjusted to maintain a partial pressure of arterial carbon dioxide of 40 ± 5 mmHg in Group 40, 50 ± 5 mmHg in Group 50 and 60 ± 5 mmHg in Group 60 during one-lung ventilation and at the end of surgery.

MAIN OUTCOME MEASURES

The primary outcome was the arterial oxygen partial pressure/fractional inspired oxygen ratio after 60 min of one-lung ventilation.

RESULTS

Data from 262 patients were analysed. The partial pressure/fractional inspired oxygen ratio was significantly higher in Group 50 and Group 60 than in Group 40 (269.4 vs. 262.9 vs. 214.4; P  < 0.001) but was not significantly different between Group 50 and Group 60. The incidence of postoperative pulmonary complications was comparable among the three groups.

CONCLUSION

Permissive hypercarbia improved lung oxygenation during one-lung ventilation without increasing the risk of postoperative pulmonary complications or the length of hospital stay.

TRIAL REGISTRATION

NCT04175379.