The ventilation parameters during the Nuss procedure for repair of pectus excavatum

Abstract

The ventilation parameters during the Nuss procedure for repair of pectus excavatum depend on surgical procedures and airway protection technique. The aim of the study: analyzing the ventilation parameters during the Nuss procedure for repair of pectus excavatum according to the airway protection technique. Material and Methods. The observational prospective study included 60 adolescents (boys/girls=47/13) who had undergone the Nuss procedure for repair of pectus excavatum under a combination of general anesthesia with different types of regional blocks. The patients were randomized into two groups (n=20 in each) according to the airway protection technique: Group S (n=32) where the patients were intubated with a standard single-lumen tube, and capnothorax with 4-6 mmHg intrapleural pressure was applied; Group D (n=28) where the patients were intubated with a double-lumen tube, and open pneumothorax was applied without additional pressure in the thoracic cavity. All patients were ventilated using PCV with changing of the parameters in relevance with EtCO2. The following parameters were analyzed: peripheral blood saturation (SpO2), inspiratory fractional oxygen concentration (FiO2), end-tidal carbon dioxide partial pressure (EtCO2), tidal volume (Tv), peak inspiratory pressure (PIP), positive end-expiratory pressure (PEEP), the number of repeated intubation attempts, and the quality of operation field visualization checked by surgeon with a 5-point scale. Results and Discussion. During capno/pneumothorax and bar rotation, in both groups SpO2 decreased up to 95%, which required increasing FiO2 up to 70% in Group D, and up to 63% in Group S (р=0.04). Applying capno/pneumothorax lead to reduced Tv, which was 52 ml less in Group D than in Group S (р=0.0001). The levels of EtCO2, PIP, and PEEP were comparable in both groups at all stages of the surgery. The number of repeated intubation attempts was- 1 case (3,1%) in group S, and 2 cases (7,1%) in group D: c2 = 0,51; p=0.48, the adjusted c22 = 3.84 for p <0.05. The quality of operation field visualization evaluated by the surgeons with the 5-point scale was better in Group D (4.5 points), than in Group S - 3 points (р<0.000001) at all stages. Conclusions. The one-lung ventilation using double-lumen left-side tube provides better operating field visualization than ventilation throw single-lumen tube with capnothorax. Both techniques supply adequate ventilation and oxygenation parameters. Key words: tracheal intubation, ventilation, pectus excavatum, Nuss procedure