Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Apr 5:15:1383167.
doi: 10.3389/fphys.2024.1383167. eCollection 2024.

Individualized positive end-expiratory pressure reduces driving pressure in obese patients during laparoscopic surgery under pneumoperitoneum: a randomized clinical trial

Tiago Batista Xavier  1   2 , Leonardo Vicente Coelho  3 , Daniel Antonio Lopes Ferreira  3 , José Manuel Cota Y Raposeiras  3 , Marcelo Sampaio Duran  3 , Leticia Almeida Silva  4 , Gabriel Casulari da Motta-Ribeiro  5 , Luciana Moisés Camilo  2 , Alysson Roncally Silva Carvalho  6   7 , Pedro Leme Silva  4
Affiliations

Individualized positive end-expiratory pressure reduces driving pressure in obese patients during laparoscopic surgery under pneumoperitoneum: a randomized clinical trial

Tiago Batista Xavier et al. Front Physiol. .

Abstract

Introduction: During pneumoperitoneum (PNP), airway driving pressure (ΔPRS) increases due to the stiffness of the chest wall and cephalic shift of the diaphragm, which favors atelectasis. In addition, depending on the mechanical power (MP) formulas, they may lead to different interpretations.

Methods: Patients >18 years of age with body mass index >35 kg/m2 were included in a single-center randomized controlled trial during their admission for bariatric surgery by abdominal laparoscopy. Intra-abdominal pressure was set at 15 mmHg at the pneumoperitoneum time point (PNP). After the recruitment maneuver, the lowest respiratory system elastance (ERS) was detected during the positive end-expiratory pressure (PEEP) step-wise decrement. Patients were randomized to the 1) CTRL group: ventilated with PEEP of 5 cmH2O and 2) PEEPIND group: ventilated with PEEP value associated with ERS that is 5% higher than its lowest level. Respiratory system mechanics and mean arterial pressure (MAP) were assessed at the PNP, 5 min after randomization (T1), and at the end of the ventilation protocol (T2); arterial blood gas was assessed at PNP and T2. ΔPRS was the primary outcome. Three MP formulas were used: MPA, which computes static PEEP × volume, elastic, and resistive components; MPB, which computes only the elastic component; and MPC, which computes static PEEP × volume, elastic, and resistive components without inspiratory holds.

Results: Twenty-eight patients were assessed for eligibility: eight were not included and 20 patients were randomized and allocated to CTRL and PEEPIND groups (n = 10/group). The PEEPIND ventilator strategy reduced ΔPRS when compared with the CTRL group (PEEPIND, 13 ± 2 cmH2O; CTRL, 22 ± 4 cmH2O; p < 0.001). Oxygenation improved in the PEEPIND group when compared with the CTRL group (p = 0.029), whereas MAP was comparable between the PEEPIND and CTRL groups. At the end of surgery, MPA and MPB were correlated in both the CTRL (rho = 0.71, p = 0.019) and PEEPIND (rho = 0.84, p = 0.020) groups but showed different bias (CTRL, -1.9 J/min; PEEPIND, +10.0 J/min). At the end of the surgery, MPA and MPC were correlated in both the CTRL (rho = 0.71, p = 0.019) and PEEPIND (rho = 0.84, p = 0.020) groups but showed different bias (CTRL, -1.9 J/min; PEEPIND, +10.0 J/min).

Conclusion: Individualized PEEP was associated with a reduction in ΔPRS and an improvement in oxygenation with comparable MAP. The MP, which solely computes the elastic component, better reflected the improvement in ΔPRS observed in the individualized PEEP group.

Clinical trial registration: The protocol was registered at the Brazilian Registry of Clinical Trials (U1111-1220-7296).

Keywords: laparoscopy; obesity; positive end-expiratory; pressure; respiratory mechanics.

PubMed Disclaimer

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The authors declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.

Figures

FIGURE 1
FIGURE 1
Timeline of the experimental procedures. ABG, arterial blood gases; CTRL, control group ventilated with PEEP of 5 cmH2O; ERS, respiratory system elastance; MV, mechanical ventilation; PEEP, positive end-expiratory pressure; PEEPIND, PEEP adjusted at ERS that is 5% higher than the PEEPminERS; PNP, pneumoperitoneum; RM, recruitment maneuver; T1, at the beginning of surgery; T2, at the end of surgery.
FIGURE 2
FIGURE 2
Representative PEEP–ERS curve. In this patient, the PEEP associated with the lowest ERS was 23 cmH2O (PEEPminERS), and the PEEP associated with the 5% higher ERS than the lowest ERS was 18 cmH2O (PEEPIND). ERS, respiratory system elastance; PEEP, positive end-expiratory pressure.
FIGURE 3
FIGURE 3
Enrolment, randomization, follow-up, and treatment. Twenty-eight patients were assessed for eligibility at the study site. Of these, 20 underwent randomization (10 to CTRL group and 10 to PEEPIND group), and eight patients were excluded for not meeting the inclusion criteria.
FIGURE 4
FIGURE 4
Correlations and Bland–Altman plot between MPA and MPB in CTRL and PEEPIND groups at T2. In the CTRL group at T2, MPA and MPB showed a positive correlation (rho = 0.71, p = 0.019), and the Bland–Altman plot showed a bias of −1.9 J/min between both formulas for mechanical power (A,B). In the PEEPIND group at T2, MPA and MPB showed a positive correlation (rho = 0.84, p = 0.020), and the Bland–Altman plot showed a bias of +10.0 J/min between both formulas for mechanical power (C,D). CTRL, control group ventilated with PEEP of 5 cmH2O; MPA, mechanical power formula: 0.098 × RR × VT × (PpeakRS − 0.5 ΔPRS); MPB, mechanical power formula: 0.098 × RR × VT × ΔPRS); PEEP, positive end-expiratory pressure; PEEPIND, PEEP adjusted at ERS that is 5% higher than the PEEPminERS; RR, respiratory rate; T2, at the end of surgery; VT, tidal volume.
FIGURE 5
FIGURE 5
Correlations and Bland–Altman plot between MPA and MPC in the CTRL and PEEPIND groups at T2. In the CTRL group at T2, MPA and MPC showed a positive correlation (rho = 0.98, p < 0.001), and the Bland–Altman plot showed a bias of 1.19 J/min between both formulas for MP (A,B). In the PEEPIND group at T2, MPA and MPC showed a positive correlation (rho = 0.98, p < 0.001), and the Bland–Altman plot showed a bias of 1.41 J/min between both formulas for MP (C,D). CTRL, control group ventilated with PEEP of 5 cmH2O; MPA, mechanical power formula: 0.098 × RR × VT × (PpeakRS − 0.5 ΔPRS); MPC, mechanical power formula: 0.098 × VT × RR × (PpeakRS + PEEP + F/6)/20; PEEP, positive end-expiratory pressure; PEEPIND, PEEP adjusted at ERS that is 5% higher than the PEEPminERS; RR, respiratory rate; T2, at the end of surgery; VT, tidal volume.
FIGURE 6
FIGURE 6
Summary of respiratory variables in the PEEPIND group in relation to the CTRL group at T2. The solid bars show the increase, and the hatched bars show the decrease in percentage. The MPA increase (+50%) was highly influenced by the increase in PEEP (+346%) and did not follow the decrease in ΔPRS and ERS (−41% and −42%, respectively). MPB (−31%) decrease followed the decrease in ΔPRS and ERS. CTRL, control group ventilated with PEEP of 5 cmH2O; ERS, respiratory system elastance; MPA, mechanical power formula: 0.098 × RR × VT × (PpeakRS − 0.5 ΔPRS); MPB, mechanical power formula: 0.098 × RR × VT × ΔPRS); MPC, mechanical power formula: 0.098 × VT × RR × (PpeakRS + PEEP + F/6)/20. PEEP, positive end-expiratory pressure; PEEPIND, PEEP adjusted at ERS that is 5% higher than the PEEPminERS; PpeakRS, peak airway pressure; Raw, airway resistance; RR, respiratory rate; T2, at the end of surgery; VT, tidal volume; ΔPRS, driving pressure.
See this image and copyright information in PMC

References

    1. Almarakbi W. A., Fawzi H. M., Alhashemi J. A. (2009). Effects of four intraoperative ventilatory strategies on respiratory compliance and gas exchange during laparoscopic gastric banding in obese patients. Br. J. Anaesth. 102, 862–868. 10.1093/bja/aep084 - DOI - PubMed
    1. Andersson L. E., Baath M., Thorne A., Aspelin P., Odeberg-Wernerman S. (2005). Effect of carbon dioxide pneumoperitoneum on development of atelectasis during anesthesia, examined by spiral computed tomography. Anesthesiology 102, 293–299. 10.1097/00000542-200502000-00009 - DOI - PubMed
    1. Ball L., Hemmes S. N. T., Serpa Neto A., Bluth T., Canet J., Hiesmayr M., et al. (2018). Intraoperative ventilation settings and their associations with postoperative pulmonary complications in obese patients. Br. J. Anaesth. 121, 899–908. 10.1016/j.bja.2018.04.021 - DOI - PubMed
    1. Ball L., Pelosi P. (2019). How I ventilate an obese patient. Crit. Care 23, 176. 10.1186/s13054-019-2466-x - DOI - PMC - PubMed
    1. Bluth T., Serpa Neto A., Schultz M. J., Pelosi P., Gama de Abreu M., Wrigge H., et al. (2019). Effect of intraoperative high positive end-expiratory pressure (PEEP) with recruitment maneuvers vs low PEEP on postoperative pulmonary complications in obese patients: a randomized clinical trial. JAMA 321, 2292–2305. 10.1001/jama.2019.7505 - DOI - PMC - PubMed