Related Experiment Video
Updated: Jun 19, 2026

Ex Vivo Porcine Experimental Model for Studying and Teaching Lung Mechanics
Published on: April 19, 2024
Restoration of pulmonary compliance after laparoscopic surgery using a simple alveolar recruitment maneuver
Ozlem S Cakmakkaya1, Guner Kaya, Fatis Altintas
1Department of Anesthesiology and Reanimation, Cerrahpasa Medical School, University of Istanbul, Istanbul, Turkey. scakmakkaya@ponv.org
Study Objective:
To test the hypothesis that a pulmonary maneuver designed to recruit additional alveoli (thereby decreasing atelectasis) applied before extubation can restore pulmonary compliance to baseline values.
Design:
Cohort study.
Setting:
Operating room of a university hospital.
Patients:
20 ASA physical status I and II patients scheduled to undergo laparoscopic radical nephrectomy.
Interventions:
Participants received a balanced general anesthesia using intermittent positive pressure ventilation. A pulmonary recruitment maneuver was performed as a single manual inflation of the lungs to 40 cm H(2)O, maintained for 10 seconds after release of pneumoperitoneum.
Measurements:
Respiratory mechanics including dynamic compliance were measured continuously using the VenTrak respiratory mechanics monitor (VenTrak; Novametrix, Wallingford, CT, USA). Respiratory measures were recorded together with arterial blood gases after induction (T1), with the patient placed in the lateral "jackknife" position (T2), 10 and 120 minutes after CO(2) insufflation (T3 and T4), immediately after desufflation in the lateral and supine positions (T5 and T6), and 10 minutes after a pulmonary recruitment maneuver at the conclusion of surgery (T7). Outcome data were analyzed using analysis of variance for repeated measures; P < 0.05 was defined as statistically significant.
Main Results:
On average, compliance decreased from an initial value of 63.5 to 52.6 mL/cm H(2)O when patients were turned from the supine to the lateral position (T1 vs. T2; P < 0.001), and decreased further to 31.07 mL/cm H(2)O after CO(2) insufflation (T2 vs. T3; P < 0.001). Compliance increased to 50.8 mL/cm H(2)O after desufflation and 54.4 mL/cm H(2)O after turning the patient to the supine position, but did not return to baseline levels until after performance of the pulmonary recruitment maneuver, 64.3 mL/cm H(2)O (T6 vs. T7; P < 0.001, and T1 vs. T7; P = 0.73).
Conclusions:
Respiratory mechanics do not fully return to baseline levels after desufflation following laparoscopy; however, lung compliance can be fully restored using a simple alveolar recruitment maneuver.
Related Concept Videos
Cardiopulmonary Resuscitation II: ACLS Airway Management
Pulmonary Cycle: Exhalation
Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
Pressure Relationships in Thoracic Cavity
Breathing Mechanisms
Both intra-alveolar and intrapleural pressures rely on specific lung properties. The ability to breathe—allowing air to enter the lungs during...
Pulmonary Ventilation: Inhalation
Boyle's law becomes particularly pertinent when examining respiratory...
Atelectasis II: Pathophysiology