1. Recruitment-to-inflation ratio to assess response to PEEP during laparoscopic surgery: A physiologic study.
- Author
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Covotta M, Claroni C, Torregiani G, Menga LS, Venti E, Gazzè G, Anzellotti GM, Ceccarelli V, Gaglioti P, Orlando S, Rosà T, Forastiere E, Antonelli M, and Grieco DL
- Subjects
- Humans, Male, Middle Aged, Aged, Head-Down Tilt, Respiratory Mechanics physiology, Ventilator-Induced Lung Injury prevention & control, Ventilator-Induced Lung Injury etiology, Lung Volume Measurements methods, Lung physiopathology, Manometry methods, Positive-Pressure Respiration methods, Laparoscopy methods, Laparoscopy adverse effects, Pneumoperitoneum, Artificial methods, Pneumoperitoneum, Artificial adverse effects, Prostatectomy adverse effects, Prostatectomy methods, Robotic Surgical Procedures methods, Robotic Surgical Procedures adverse effects
- Abstract
Study Objective: During laparoscopic surgery, the role of PEEP to improve outcome is controversial. Mechanistically, PEEP benefits depend on the extent of alveolar recruitment, which prevents ventilator-induced lung injury by reducing lung dynamic strain. The hypotheses of this study were that pneumoperitoneum-induced aeration loss and PEEP-induced recruitment are inter-individually variable, and that the recruitment-to-inflation ratio (R/I) can identify patients who benefit from PEEP in terms of strain reduction., Design: Sequential study., Setting: Operating room., Patients: Seventeen ASA I-III patients receiving robot-assisted prostatectomy during Trendelenburg pneumoperitoneum., Interventions and Measurements: Patients underwent end-expiratory lung volume (EELV) and respiratory/lung/chest wall mechanics (esophageal manometry and inspiratory/expiratory occlusions) assessment at PEEP = 0 cmH
2 O before and after pneumoperitoneum, at PEEP = 4 and 12 cmH2 O during pneumoperitoneum. Pneumoperitoneum-induced derecruitment and PEEP-induced recruitment were assessed through a simplified method based on multiple pressure-volume curve. Dynamic and static strain changes were evaluated. R/I between 12 and 4 cmH2 O was assessed from EELV. Inter-individual variability was rated with the ratio of standard deviation to mean (CoV)., Main Results: Pneumoperitoneum reduced EELV by (median [IqR]) 410 mL [80-770] (p < 0.001) and increased dynamic strain by 0.04 [0.01-0.07] (p < 0.001), with high inter-individual variability (CoV = 70% and 88%, respectively). Compared to PEEP = 4 cmH2 O, PEEP = 12 cmH2 O yielded variable amount of recruitment (139 mL [96-366] CoV = 101%), causing different extent of dynamic strain reduction (median decrease 0.02 [0.01-0.04], p = 0.002; CoV = 86%) and static strain increases (median increase 0.05 [0.04-0.07], p = 0.01, CoV = 33%). R/I (1.73 [0.58-3.35]) estimated the decrease in dynamic strain (p ≤0.001, r = -0.90) and the increase in static strain (p = 0.009, r = -0.73) induced by PEEP, while PEEP-induced changes in respiratory and lung mechanics did not., Conclusions: Trendelenburg pneumoperitoneum yields variable derecruitment: PEEP capability to revert these phenomena varies significantly among individuals. High R/I identifies patients in whom higher PEEP mostly reduces dynamic strain with limited static strain increases, potentially allowing individualized settings., Competing Interests: Declaration of competing interest DLG reports speaking fees or support for travel expenses by GE Healthcare, Intersurgical, Fisher and Paykel, Gilead and Pfizer. MA has received personal fees from Maquet, and a research grant by Toray. DLG and MA disclose a research grant by General Electric Healthcare., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
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