Pneumoperitoneum deteriorates intratidal respiratory system mechanics: an observational study in lung-healthy patients.
Pneumoperitoneum during laparoscopic surgery leads to atelectasis and impairment of oxygenation. Positive end-expiratory pressure (PEEP) is supposed to counteract atelectasis. We hypothesized that the derecruiting effects of pneumoperitoneum would deteriorate the intratidal compliance profile in patients undergoing laparoscopic surgery.



In 30 adult patients scheduled for surgery with pneumoperitoneum, respiratory variables were measured during mechanical ventilation. We calculated the dynamic compliance of the respiratory system (CRS) and the intratidal volume-dependent CRScurve using the gliding-SLICE method. The CRScurve was then classified in terms of indicating intratidal recruitment/derecruitment (increasing profile) and overdistension (decreasing profile). During the surgical interventions, the PEEP level was maintained nearly constant at 7 cm H2O. Data are expressed as mean [confidence interval].



Baseline CRSwas 60 [54-67] mL cm H2O-1. Application of pneumoperitoneum decreased CRSto 40 [37-43] mL cm H2O-1which partially recovered to 54 [50-59] mL cm H2O-1(P < 0.001) after removal but remained below the value measured before pneumoperitoneum (P < 0.001). Baseline compliance profiles indicated intratidal recruitment/derecruitment in 48 % patients. After induction of pneumoperitoneum, intratidal recruitment/derecruitment was indicated in 93 % patients (P < 0.01), and after removal intratidal recruitment/derecruitment was indicated in 59 % patients. Compliance profiles showing overdistension were not observed.



Analyses of the intratidal compliance profiles reveal that pneumoperitoneum during laparoscopic surgery causes intratidal recruitment/derecruitment which partly persists after its removal. The analysis of the intratidal volume-dependent CRSprofiles could be used to guide intraoperative PEEP adjustments during elevated intraabdominal pressure.
Department of Anesthesiology and Critical Care, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany. steffen.wirth@uniklinik-freiburg.de.
Steffen
S
Wirth
Department of Anesthesiology and Critical Care, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany.
Andreas
A
Biesemann
Department of Anesthesiology and Critical Care, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany.
Johannes
J
Spaeth
Department of Anesthesiology and Critical Care, Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany.
Stefan
S
Schumann
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D010535:Laparoscopy / Q000379:methods; D008168:Lung / Q000502:physiology / Q000503:physiopathology*; D008170:Lung Compliance; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects*; D011175:Positive-Pressure Respiration / Q000379:methods*; D001261:Pulmonary Atelectasis / Q000517:prevention & control*; D015656:Respiratory Mechanics; D013990:Tidal Volume
Compliance–volume curve; Lung compliance; Mechanical ventilation; Pneumoperitoneum; Protective ventilation; Respiratory system mechanics