<figure><img src="image_1.png" /></figure>

HAL
open science

# Intraoperative PEEP setting: should we measure the lung or the patient?

Mathilde Lepeyre, Joris Pensier, Gaetano Scaramuzzo

► To cite this version:

Mathilde Lepeyre, Joris Pensier, Gaetano Scaramuzzo. Intraoperative PEEP setting: should we measure the lung or the patient?. Anaesthesia Critical Care & Pain Medicine, 2025, pp.101715. 10.1016/j.accpm.2025.101715. hal-05389081

HAL Id: hal-05389081

https://hal.science/hal-05389081v1

Submitted on 14 Feb 2026

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_2.png" /></figure>

Distributed under a Creative Commons CC BY 4.0 - Attribution - International License
# Intraoperative PEEP setting: should we measure the lung or the patient?

Mathilde Lepeyre <fnref n="1" />, Joris Pensier <fnref n="2" />, Gaetano Scaramuzzo <fnref n="3" />

**Keywords:**

Body mass index; Esophageal pressure; Positive end-expiratory pressure.

<footnote n="1">¹ Department of Perioperative Medicine, CHU Clermont-Ferrand, Clermont-Ferrand, France.</footnote>

<footnote n="2">² Anesthesia and Critical Care Department B, Saint Eloi Teaching Hospital, PhyMedExp, University of Montpellier, INSERM U1046, Montpellier, France; Department of Anesthesia, Critical Care and Pain Medicine, Center for Anesthesia Research Excellence, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA, 02215, United States. Electronic address: j-pensier@chu-montpellier.fr.</footnote>

<footnote n="3">³ Department of Translational Medicine, University of Ferrara, Ferrara, Italy; Emergency Department, Ferrara University Hospital, Ferrara, Italy.</footnote>
Over the past decade, the concept of individualizing perioperative ventilation has evolved from a physiological to a pragmatic clinical goal. Increasing evidence suggests that personalizing positive-end expiratory pressure (PEEP) in surgical patients can enhance its benefits while reducing the risk of collateral side effects [1], such as ventilator-induced lung injury (VILI) or, in its main clinical counterpart in the post-surgical setting, postoperative pulmonary complications [2, 3]. This might be particularly important in some categories of patients, such as those exposed to high intrabdominal pressures, steep Trendelenburg position, or with higher body mass index (BMI). Specifically, PEEP in patients with obesity has been shown to be effective in preventing pulmonary complications at all stages of the perioperative care [4, 5].

Despite the high level of physiological evidence supporting a personalized approach, the ideal target to be used to set PEEP remains to be established. In this context, a simple anthropometric formula, i.e., BMI/3, has been suggested as a pragmatic way to personalize PEEP without additional equipment [6]. The advantages of this approach are clear: it is noninvasive, rapidly acquired, and already available before anesthesia induction. It can be useful as an initial PEEP setting in the operating room where time and attention compete with multiple priorities. Nevertheless, previous studies in both acute respiratory distress syndrome (ARDS) and surgical patients showed that the relationship between pleural pressure, superimposed pressure, and obesity is complex and nonlinear [7, 8]. Since chest-wall elastance, abdominal pressure, diaphragm geometry, and lung-chest wall coupling vary widely across individuals and across time [9], the “physiology-based” PEEP that avoids collapse and overdistension may diverge substantially from the “anthropometric PEEP” derived from BMI/3. Thus, in order to personalize PEEP in the operating room, should we measure the patient or the lung?

To investigate this question, Lentz *et al.* [10] evaluated how well this anthropometric formula performs as compared with esophageal pressure, in the present issue of *Anaesthesia Critical Care and Pain Medicine*. Across 109 included patients – 103 analyzed – undergoing laparoscopic abdominal surgery monitored with esophageal manometry, Lentz *et al.* studied the difference between the PEEP set following the BMI/3 rule and the PEEP set to reach 0 cmH₂O of end-expiratory transpulmonary pressure (PL) [10]. In their interesting research, Lentz *et al.* show that the anthropometric rule (BMI/3) tends to capture the overall BMI group, but might fail to describe the interpatient variability [10]. While a fixed PEEP of 10 cmH₂O estimated the end-expiratory PL target (with a ±2 cmH₂O tolerance band) in 27% of the patients, the anthropometric rule only moderately increased precision, as only 37% of the patients (38/103) reached the end-expiratory PL target. It was not rare for a discordance to exceed 5 cmH₂O (33/103, 32%), reducing the sensitivity and the level of personalization [10].

Esophageal manometry monitoring has shown its usefulness in many clinical contexts, such as obesity [11], laparoscopic surgery [12], and ARDS [13]. In these contexts, the contribution of the chest wall to measured pressures can be so great that conventional ventilator readings become misleading. A high plateau pressure does not always mean alveolar overdistension but might simply reflect increased chest wall weight. Conversely, apparently “safe” airway pressures can conceal excessive pulmonary stress. Transpulmonary pressure thus provides a more refined physiological lens and paves the way for truly personalized ventilation. Lentz *et al.* showed that the manometry-guided PEEP varied from 0.3 to 30.3 cmH₂O, underscoring how heterogeneous the “optimal” PEEP can be between patients [10].
<figure><img src="image_3.png" /><figcaption>**Figure 1.** Intraoperative PEEP setting: measure the patient vs measure the lung PEEP: positive end-expiratory pressure, BMI: body mass index, EIT: electric impedance tomography.</figcaption></figure>

Despite its physiological precision, esophageal pressure guidance is not easily implementable in clinical practice (Figure 1). Placement, calibration, and titration demand expertise, methodical checks [14]. Artifact and mediastinal weight can bias values, and the dynamic conditions of abdominal surgery (insufflation, changes in body position, or stepwise alterations in chest-wall mechanics) force repeated reassessment and occasional repositioning [15]. These pragmatic issues explain why esophageal manometry is a robust physiological tool rather than a clinical gold standard [16].

Moreover, uncertainty about the correct physiologic target compounds the implementation challenge. The EPVent trial proposed targeting positive end-expiratory transpulmonary pressure in ARDS patients [13], but subsequent work suggested that such a target can promote overdistension in an important subset of patients [17]. More recent proposals suggest keeping the end-expiratory transpulmonary pressure close to zero, frequently implemented as a tolerance band such as -2 to +2 cmH₂O [17]. Thus, the target chosen by the authors is in line with contemporary physiological understanding [10]. Importantly, these concepts were forged primarily in ARDS rather than in routine intraoperative care of patients with obesity [13, 18, 19]. Extrapolation from these static physiologic targets to the operating room must therefore be carried out carefully, especially when pneumoperitoneum and positioning shift pleural pressure in ways that ARDS trials did not model. The broader perioperative literature similarly tempers enthusiasm for universal recipes: neutral results of population-level strategies, such as fixed PEEP tables or universal driving pressure targets, remind us that average effects can mask individual benefit and harm [16, 20].

Furthermore, practical applicability in anesthesia is another limiting factor. Esophageal balloon is contraindicated or cumbersome in some upper gastrointestinal procedures, and even when placement is feasible, the signal must be interpreted in the moving target of laparoscopic pressure changes and Trendelenburg or reverse-Trendelenburg positioning [15].
As esophageal pressure, another regional physiology-based method, electrical impedance tomography (EIT), may offer a useful noninvasive surrogate for regional aeration and overdistension, complementing or substituting for esophageal manometry [21, 22]. Nevertheless, EIT in the operative room has its own constraints: belt positioning can conflict with surgical access, motion and draping may degrade signal quality, and interpretation requires training and workflow integration that are not currently standard. As with manometry, the promise is real, but the path to reliable routine use is incremental rather than instantaneous.

A pragmatic and wise approach may be, therefore, to wisely use the information provided by Lentz and colleagues to implement a subsequent clinical plan [10]. When advanced monitoring is not feasible or in case of patients or procedures with low probability of pulmonary complications, starting with BMI/3 [6] and complementing with ventilatory-based data can be a good strategy [23, 24]. In these cases, when precise fine-tuning is not available, BMI/3 could constitute a practical starting point rather than an alternative method. In high-risk patients, long surgeries, or when the BMI/3-based PEEP is insufficient to provide lung protection, advanced physiology-based tools such as esophageal manometry or electrical impedance tomography can provide valuable guidance for higher-stakes clinical decisions. Use manometry to target an end-expiratory transpulmonary pressure near 0 cmH₂O within a reasonable tolerance (±2 cmH₂O) [17], and/or supplement this information with EIT, which provides a real-time view of regional aeration to estimate dorsal collapse or ventral overdistension [24], guiding small PEEP adjustments and confirming the trade-offs implied by transpulmonary targets.

Moreover, the BMI/3 rule does not account for the dynamic changes in chest wall elastance that can happen during surgery, due to patient positioning or increased intraabdominal pressure [12, 15]. The accordance between advanced physiology and anthropometric rules in these conditions is yet to be explored. Reassessing respiratory signals after pneumoperitoneum and position changes, and again before emergence, is warranted to ensure coherence across global mechanics, regional ventilation, and hemodynamics. Unfortunately, such integration cannot be achieved through simple anthropometric data, given the variability in surgical positioning, intra-abdominal pressure, and patient-specific mechanics [16].

Finally, adjusting PEEP cannot be viewed solely through a pulmonary lens. Increases in intrathoracic pressure significantly impact cardiovascular function: reducing venous return, altering preload, and overloading the right ventricle [25, 26]. Hemodynamic stability and optimized volume status are therefore essential prerequisites for any PEEP titration-guided or any personalized PEEP technique.

In the operating room, both physiological trials and meta-analyses [2, 6] suggest that a personalized approach to PEEP improves oxygenation and compliance, particularly in settings with substantial extrinsic constraints. While robust outcome data are still lacking, the physiological rationale remains compelling. To the initial question, "should we measure the patient or the lung?", Lentz et al.'s findings may suggest a nuanced answer: BMI-based rules offer simplicity and accessibility, whereas physiology-based measurements provide precision [10]. The optimal approach likely lies in their thoughtful combination. While the coming years will determine which personalized approach to use and when, it is surely becoming clearer that a one-
size-fits-all all cannot be an optimal strategy, both in the ICU and in the OR [27]. Finding the right balance between physiological precision and possibility of clinical broad implementation will be the next challenge, and surely the excellent research we discussed is going in this direction.

## Funding

None

## Declaration of Interest

JP received funding from the Société Française d’Anesthésie-Réanimation, the Philippe Foundation, the Beth Israel Deaconess Medical Center (Boston, MA) and the University Hospital of Montpellier. Other authors declare no competing interests

## References

1. Pereira SM, Tucci MR, Morais CCA, Simões CM, Tonelotto BFF, Pompeo MS, et al. Individual Positive End-expiratory Pressure Settings Optimize Intraoperative Mechanical Ventilation and Reduce Postoperative Atelectasis. Anesthesiology. 2018;129:1070-81. https://doi.org/10.1097/ALN.0000000000002435.

2. Zhou L, Li H, Li M, Liu L. Individualized positive end-expiratory pressure guided by respiratory mechanics during anesthesia for the prevention of postoperative pulmonary complications: a systematic review and meta-analysis. J Clin Monit Comput. 2023;37:365-77. https://doi.org/10.1007/s10877-022-00960-9.

3. Ferrando-Ortolá C, Rodríguez A, Becerra Á, Cabrera S, Guerra E, Focaccio C-A, et al. Postoperative pulmonary complications in emergency abdominal surgery. A prospective international cohort study. Anaesth Crit Care Pain Med. 2025;44:101560. https://doi.org/10.1016/j.accpm.2025.101560.

4. Nestler C, Simon P, Petroff D, Hammermüller S, Kamrath D, Wolf S, et al. Individualized positive end-expiratory pressure in obese patients during general anaesthesia: a randomized controlled clinical trial using electrical impedance tomography. Br J Anaesth. 2017;119:1194-205. https://doi.org/10.1093/bja/aex192.

5. Pensier J, Naudet-Lasserre A, Monet C, Capdevila M, Aarab Y, Lakbar I, et al. Noninvasive respiratory support following extubation in critically ill adults with obesity: a systematic review and network meta-analysis. eClinicalMedicine. 2025;79:103002. https://doi.org/10.1016/j.eclinm.2024.103002.
6. Selpien H, Penon J, Thunecke D, Schädler D, Lautenschläger I, Ohnesorge H, et al. Adjustment of positive end-expiratory pressure based on body mass index during general anaesthesia: a randomised controlled trial*. Anaesthesia. 2025;80:1322–32.
https://doi.org/10.1111/anae.16656.

7. Spina S, Mantz L, Xin Y, Moscho DC, Ribeiro De Santis Santiago R, Grassi L, et al. The pleural gradient does not reflect the superimposed pressure in patients with class III obesity. Crit Care. 2024;28:306. https://doi.org/10.1186/s13054-024-05097-6.

8. Hedenstierna G, Tokics L, Scaramuzzo G, Rothen HU, Edmark L, Öhrvik J. Oxygenation Impairment during Anesthesia: Influence of Age and Body Weight. Anesthesiology. 2019;131:46–57. https://doi.org/10.1097/ALN.0000000000002693.

9. Capdevila M, Schiavoni L, Jaber S. Intraoperative individualised ventilation: importance of targeted reassessment. Anaest Crit Care Pain Med. 2025;101629. https://doi.org/10.1016/j.accpm.2025.101629.

10. Lentz S, Serigano O, Tharp WG. Identifying Optimal Positive End-Expiratory Pressure by Body Mass Index Does Not Account for Natural Physiologic Variability in Pleural Pressure. Anaesth Crit Care Pain Med. 2025;101684. doi: 10.1016/j.accpm.2025.101684.

11. Alvey NJ, Hlaing M, Piccoli J, Kukreja N, Tran TT. Positive end-expiratory pressure titration via esophageal balloon monitoring in a morbidly obese patient undergoing laparoscopic nephrectomy. Can J Anesth Can Anesth. 2020;67:1086–7.
https://doi.org/10.1007/s12630-020-01606-7.

12. Tharp WG, Murphy S, Breidenstein MW, Love C, Booms A, Rafferty MN, et al. Body Habitus and Dynamic Surgical Conditions Independently Impair Pulmonary Mechanics during Robotic-assisted Laparoscopic Surgery: A Cross-sectional Study. Anesthesiology. 2020;133:750–63. https://doi.org/10.1097/ALN.0000000000003442.

13. Beitler JR, Sarge T, Banner-Goodspeed VM, Gong MN, Cook D, Novack V, et al. Effect of Titrating Positive End-Expiratory Pressure (PEEP) With an Esophageal Pressure–Guided Strategy vs an Empirical High PEEP-F IO2 Strategy on Death and Days Free From Mechanical Ventilation Among Patients With Acute Respiratory Distress Syndrome: A Randomized Clinical Trial. JAMA. 2019;321:846. https://doi.org/10.1001/jama.2019.0555.

14. Mojoli F, Iotti GA, Torriglia F, Pozzi M, Volta CA, Bianzina S, et al. In vivo calibration of esophageal pressure in the mechanically ventilated patient makes measurements reliable. Crit Care. 2016;20:98. https://doi.org/10.1186/s13054-016-1278-5.

15. Scaramuzzo G, Priani P, Ferrara P, Verri M, Montanaro F, La Rosa R, et al. Longitudinal changes of electrical impedance tomography-based best PEEP in obese patients undergoing laparoscopic surgery: A prospective physiological study. Anaesth Crit Care Pain Med. 2025;44:101569. https://doi.org/10.1016/j.accpm.2025.101569.
16. Pensier J, Guerrero MA, Berger-Estilita J, Borgstedt L, Zaher AMS, Jaber S, et al. Perioperative ventilation support, what clinicians and searchers must know. Anaesth Crit Care Pain Med. 2025;44:101554. https://doi.org/10.1016/j.accpm.2025.101554.

17. Sarge T, Baedorf-Kassis E, Banner-Goodspeed V, Novack V, Loring SH, Gong MN, et al. Effect of Esophageal Pressure-guided Positive End-Expiratory Pressure on Survival from Acute Respiratory Distress Syndrome: A Risk-based and Mechanistic Reanalysis of the EPVent-2 Trial. Am J Respir Crit Care Med. 2021;204:1153-63. https://doi.org/10.1164/rccm.202009-3539OC.

18. Pensier J, Fosset M, Paschold B-S, von Wedel D, Redaelli S, Braeuer BLP, et al. Temporal stability of phenotypes of acute respiratory distress syndrome: clinical implications for early corticosteroid therapy and mortality. Intensive Care Med. 2025. https://doi.org/10.1007/s00134-025-08089-4.

19. Renard Triché L, Fosset M, Jabaudon M, Futier E, Lucas B, Latroche C, et al. Temporal stability of inflammatory subphenotypes of acute respiratory distress syndrome: 28-day insights from the ICAR trial. Anaesth Crit Care Pain Med. 2025;44:101559. https://doi.org/10.1016/j.accpm.2025.101559.

20. Futier E, De Jong A, Cirenei C, Godet T, Jabaudon M, Constantin J-M, et al. Personalized driving pressure-guided positive end-expiratory pressure in patients at risk of postoperative respiratory failure (IMPROVE-2): a multicenter, pragmatic, randomized clinical trial. Intensive Care Med. 2025;51:1797-808. https://doi.org/10.1007/s00134-025-08082-x.

21. Scaramuzzo G, Pavlovsky B, Adler A, Baccinelli W, Bodor DL, Damiani LF, et al. Electrical impedance tomography monitoring in adult ICU patients: state-of-the-art, recommendations for standardized acquisition, processing, and clinical use, and future directions. Crit Care. 2024;28:377. https://doi.org/10.1186/s13054-024-05173-x.

22. Scaramuzzo G, Spadaro S, Dalla Corte F, Waldmann AD, Böhm SH, Ragazzi R, et al. Personalized Positive End-Expiratory Pressure in Acute Respiratory Distress Syndrome: Comparison Between Optimal Distribution of Regional Ventilation and Positive Transpulmonary Pressure. Crit Care Med. 2020;48:1148-56. https://doi.org/10.1097/CCM.0000000000004439.

23. Rosà T, Menga LS, Mastropietro C, Settanni D, Russo A, Frassanito L, et al. Evaluation of the Potential for Lung Recruitment with the Recruitment-to-Inflation Ratio during General Anesthesia. Anesthesiology. 2025;143:1211-24. https://doi.org/10.1097/ALN.0000000000005677.

24. Spinelli E, Mauri T, Fogagnolo A, Scaramuzzo G, Rundo A, Grieco DL, et al. Electrical impedance tomography in perioperative medicine: careful respiratory monitoring for tailored interventions. BMC Anesthesiol. 2019;19:140. https://doi.org/10.1186/s12871-019-0814-7.

25. Grillot N, Gonzalez V, Deransy R, Rouhani A, Cintrat G, Rooze P, et al. Post-induction hypotension during rapid sequence intubation in the operating room: A post hoc analysis of the randomized controlled REMICRUSH trial. Anaesth Crit Care Pain Med. 2025;44:101502. https://doi.org/10.1016/j.accpm.2025.101502.

26. Leone M, Russell L, Cecconi M, Khanna AK, Pirracchio R, Bauer M, et al. Hemodynamic failure during sepsis: What clinicians and researchers must know. Anaesth Crit Care Pain Med. 2025;44:101602. https://doi.org/10.1016/j.accpm.2025.101602.
27. Capdevila M, Pensier J, De Jong A, Jung B, Beghin J, Laumon T, et al. Impact of Underassisted Ventilation on Diaphragm Function and Structure in a Porcine Model. Anesthesiology. 2025;142:896–906. https://doi.org/10.1097/ALN.00000000000005390.
<figure><img src="image_4.png" /></figure>