Effect of an Individualized Lung Protective Ventilation on Lung Strain and Stress in Children Undergoing Laparoscopy: An Observational Cohort Study.

BACKGROUND: Exaggerated lung strain and stress could damage lungs in anesthetized children. The authors hypothesized that the association of capnoperitoneum and lung collapse in anesthetized children increases lung strain-stress. Their primary aim was to describe the impact of capnoperitoneum on lung strain-stress and the effects of an individualized protective ventilation during laparoscopic surgery in children. METHODS: The authors performed an observational cohort study in healthy children aged 3 to 7 yr scheduled for laparoscopic surgery in a community hospital. All received standard protective ventilation with 5 cm H2O of positive end-expiratory pressure (PEEP). Children were evaluated before capnoperitoneum, during capnoperitoneum before and after lung recruitment and optimized PEEP (PEEP adjusted to get end-expiratory transpulmonary pressure of 0), and after capnoperitoneum with optimized PEEP. The presence of lung collapse was evaluated by lung ultrasound, positive Air-Test (oxygen saturation measured by pulse oximetry 96% or less breathing 21% O2 for 5 min), and negative end-expiratory transpulmonary pressure. Lung strain was calculated as tidal volume/end-expiratory lung volume measured by capnodynamics, and lung stress as the end-inspiratory transpulmonary pressure. RESULTS: The authors studied 20 children. Before capnoperitoneum, mean lung strain was 0.20 ± 0.07 (95% CI, 0.17 to 0.23), and stress was 5.68 ± 2.83 (95% CI, 4.44 to 6.92) cm H2O. During capnoperitoneum, 18 patients presented lung collapse and strain (0.29 ± 0.13; 95% CI, 0.23 to 0.35; P < 0.001) and stress (5.92 ± 3.18; 95% CI, 4.53 to 7.31 cm H2O; P = 0.374) increased compared to before capnoperitoneum. During capnoperitoneum and optimized PEEP, children presenting lung collapse were recruited and optimized PEEP was 8.3 ± 2.2 (95% CI, 7.3 to 9.3) cm H2O. Strain returned to values before capnoperitoneum (0.20 ± 0.07; 95% CI, 0.17 to 0.22; P = 0.318), but lung stress increased (7.29 ± 2.67; 95% CI, 6.12 to 8.46 cm H2O; P = 0.020). After capnoperitoneum, strain decreased (0.18 ± 0.04; 95% CI, 0.16 to 0.20; P = 0.090), but stress remained higher (7.25 ± 3.01; 95% CI, 5.92 to 8.57 cm H2O; P = 0.024) compared to before capnoperitoneum. CONCLUSIONS: Capnoperitoneum increased lung strain in healthy children undergoing laparoscopy. Lung recruitment and optimized PEEP during capnoperitoneum decreased lung strain but slightly increased lung stress. This little rise in pulmonary stress was maintained within safe, lung-protective, and clinically acceptable limits.

Lung recruitment prevents collapse during laparoscopy in children: A randomised controlled trial.

BACKGROUND: Capnoperitoneum and anaesthesia impair lung aeration during laparoscopy in children. These changes can be detected and monitored at the bedside by lung ultrasound (LUS). OBJECTIVE: The aim of our study was to assess the impact of general anaesthesia and capnoperitoneum on lung collapse and the potential preventive effect of lung recruitment manoeuvres, using LUS in children undergoing laparoscopy. DESIGN: Randomised controlled study. SETTING: Single-institution study, community hospital, Mar del Plata, Argentina. PATIENTS: Forty-two children American Society of Anesthesiologists I-II aged 6 months to 7 years undergoing laparoscopy. INTERVENTIONS: All patients were studied using LUS before, during and after capnoperitoneum. Children were allocated to a control group (C-group, n=21) receiving standard protective ventilation, or to a lung recruitment manoeuvre group (RM-group) (n=21), in which lung recruitment manoeuvres were performed after recording baseline LUS images before capnoperitoneum. Loss of aeration was scored by summing a progressive grading from 0 to 3 assigned to each of 12 lung areas, based on the detection of four main ultrasound patterns: normal aeration = 0, partial loss-mild = 1, partial loss-severe = 2, total loss-consolidation = 3. MAIN OUTCOME MEASURES: Lung aeration score and atelectasis assessed by ultrasound. RESULTS: Before capnoperitoneum and recruitment manoeuvres in the treated group the two groups presented similar ultrasound scores (5.95 ±â€Š4.13 vs. 5.19 ±â€Š3.33, P = 0.5). In the RM-group, lung aeration significantly improved both during (2.71 ±â€Š2.47) and after capnoperitoneum (2.52 ±â€Š2.86), compared with the C-group (6.71 ±â€Š3.54, P < 0.001, and 8.48 ±â€Š3.22, P < 0.001, respectively). There was no statistically significant difference in the percentage of atelectasis before capnoperitoneum and recruitment manoeuvres in the RM-group (62%) and in the C-group (47%, P = 0.750). However, during capnoperitoneum, only 19% of the RM-group had atelectasis compared with 80% in the C-group (P < 0.001). CONCLUSION: The majority of children undergoing laparoscopy have anaesthesia-induced atelectasis. In most cases, lung collapse due to capnoperitoneum could have been prevented by recruitment manoeuvres followed by positive-end expiratory pressure. TRIAL REGISTRY NUMBER: NCT02824146.