Novel ventilation techniques in children

Capnodynamic end-expiratory lung volume assessment in anesthetized healthy children

BACKGROUND

Capnodynamic lung function monitoring generates variables that may be useful for pediatric perioperative ventilation.

AIMS

Establish normal values for end-expiratory lung volume CO2 in healthy children undergoing anesthesia and to compare these values to previously published values obtained with alternative end-expiratory lung volume methods. The secondary aim was to investigate the ability of end-expiratory lung volume CO2 to react to positive end-expiratory pressure-induced changes in end-expiratory lung volume. In addition, normal values for associated volumetric capnography lung function variables were examined.

METHODS

Fifteen pediatric patients with healthy lungs (median age 8 months, range 1-36 months) undergoing general anesthesia were examined before start of surgery. Tested variables were recorded at baseline positive end-expiratory pressure 3 cmH2 O, 1 and 3 min after positive end-expiratory pressure 10 cmH2 O and 3 min after returning to baseline positive end-expiratory pressure 3 cmH2 O.

RESULTS

Baseline end-expiratory lung volume CO2 was 32 mL kg-1 (95% CI 29-34 mL kg-1 ) which increased to 39 mL kg-1 (95% CI 35-43 mL kg-1 , p < .0001) and 37 mL kg-1 (95% CI 34-41 mL kg-1 , p = .0003) 1 and 3 min after positive end-expiratory pressure 10 cmH2 O, respectively. End-expiratory lung volume CO2 returned to baseline, 33 mL kg-1 (95% CI 29-37 mL kg-1 , p = .72) 3 min after re-establishing positive end-expiratory pressure 3 cmH2 O. Airway dead space increased from 1.1 mL kg-1 (95% CI 0.9-1.4 mL kg-1 ) to 1.4 (95% CI 1.1-1.8 mL kg-1 , p = .003) and 1.5 (95% CI 1.1-1.8 mL kg-1 , p < .0001) 1 and 3 min after positive end-expiratory pressure 10 cmH2 O, respectively, and 1.2 mL kg-1 (95% CI 0.9-1.4 mL kg-1 , p = .08) after 3 min of positive end-expiratory pressure 3 cmH2 O. Additional volumetric capnography and lung function variables showed no major changes in response to positive end-expiratory pressure variations.

CONCLUSIONS

Capnodynamic noninvasive and continuous end-expiratory lung volume CO2 values assessed during anesthesia in children were in close agreement with previously reported end-expiratory lung volume values generated by alternative methods. Furthermore, positive end-expiratory pressure changes resulted in physiologically expected end-expiratory lung volume CO2 responses in a timely manner, suggesting that it can be used to trend end-expiratory lung volume changes during anesthesia.

Evaluation of the Puritan Bennett™ 980 Ventilator System Safety and Performance in the Real-World Setting

Purpose

Mechanical ventilation is a life-supporting intervention but is associated with known risks and complications. To improve the efficacy and safety profile of mechanical ventilation, manufacturers have developed advanced ventilator settings, modes, and alarm strategies to optimize ventilation for patient needs while avoiding complications. However, there is little real-world data published on the deployment of ventilator technology. The main objective of this study was to assess the clinical safety and performance of the Puritan Bennett™ 980 Ventilator System (PB980) using real-world clinical data collected from a diverse, global patient population.

Methods

This was a multi-center, post-market registry study that included nine sites: four in the United States of America, one in Europe, and four in China. Patients were enrolled into the registry if they were intended to be treated with a PB980. Data collection began at the start of ventilation and continued until extubation off the ventilator or up to seven days of ventilation, whichever occurred first. Subjects were divided by age into three categories: infants (0-365 days), pediatric (1-17 years), and adult (18 years and older). The primary outcome was device-related complication rate.

Results

Two-hundred-and-eleven subjects were enrolled (41 infants, 48 pediatric, and 122 adults). Sixteen deaths, unrelated to device deficiency, occurred during the data collection timeframe (relative frequency: 7.58, 95% CI: 4.40, 12.0). Only one device-related adverse event was reported (relative frequency: 0.47% 95% CI: 0.01%, 2.61%).

Conclusion

Ventilation by the PB980 was delivered safely in this multi-center observational study, which included a diverse sample of patients with broad ventilatory needs.

Comparison of TritubeTM Tube and Evone® ventilator use with traditional narrow-lumen tube use in microlaryngeal surgery cases

Comparison of TritubeTM Tube and Evone® Ventilator Use with Traditional Narrow-Lumen Tube Use in Microlaryngeal Surgery Cases ABSTRACT Introduction: Upper airway surgery involves certain difficulties, such as tumors located in the endotracheal area, narrowing of the tracheal lumen by the tumor, the use of a narrow lumen tube constantly increasing pressure. In the literature, difficult airway management has been successfully performed in patients intubated with Tritube™ and ventilated with Evone® (Ventinova Medical, Eindhoven, The Netherlands), and the benefits of these tools during laryngeal surgery have been reported. Objectives: To evaluate the feasibility and safety of the Tritube™ tube and Evone® ventilator and compare patients intubated using Tritube™ and ventilated with flow-controlled ventilation (FCV) using Evone® (TT–FCV group) to those intubated using a traditional microlaryngeal intubation tube and ventilated with volume-controlled ventilation (MLT-VCV group) in terms of perioperative parameters and outcomes during microlaryngeal surgery (MLS). Materials and Methods: After receiving their informed consent, 18 patients were randomly assigned to two groups. Patients older than 18 years, who were scheduled for elective MLS were included in the study. The patients’ demographic parameters, American Society of Anesthesiology physical status (ASA), Mallampati and Cormack-Lehane scores, duration of ventilation, duration of surgery, hemodynamic parameters, ventilation parameters, and complications were recorded. Results: When the intraoperative respiratory and hemodynamic parameters of the patients were compared between the two groups, the intraoperative cerebral oxygen saturation (SpO₂) (p=0.020), tidal volume (p=0.005), compliance of the respiratory system (p=0.001), and post-extubation SpO₂ (p=0.001) values were statistically significantly higher in the TT-FVC group compared to the MLT-VCV group. Right SpO₂ (p=0.038), left SpO₂ (p=0.047), and time to extubation (p=0.021) were statistically significantly lower in the TT-FVC group compared to the MLT-VCV group. Discussion: Low airway peak pressure and stable hemodynamics were achieved with Tritube™, and no complications were encountered in the perioperative period. At the end of the surgery, the cuff was lowered, high-frequency jet ventilation was applied, and extubation was safe performed (3). Although the literature on TritubeTM and Evone® is still limited, the use of these tools in MLS appears to be advantageous to achieve safe airway management. Keywords: Microlaryngeal surgery, Ventilation, Hemodynamics

Flow-controlled ventilation maintains gas exchange and lung aeration in a pediatric model of healthy and injured lungs: A randomized cross-over experimental study

Flow-controlled ventilation (FCV) is characterized by a constant flow to generate active inspiration and expiration. While the benefit of FCV on gas exchange has been demonstrated in preclinical and clinical studies with adults, the value of this modality for a pediatric population remains unknown. Thus, we aimed at observing the effects of FCV as compared to pressure-regulated volume control (PRVC) ventilation on lung mechanics, gas exchange and lung aeration before and after surfactant depletion in a pediatric model. Ten anesthetized piglets (10.4 ± 0.2 kg) were randomly assigned to start 1-h ventilation with FCV or PRVC before switching the ventilation modes for another hour. This sequence was repeated after inducing lung injury by bronchoalveolar lavage and injurious ventilation. The primary outcome was respiratory tissue elastance. Secondary outcomes included oxygenation index (PaO₂/FiO₂), PaCO₂, intrapulmonary shunt (Qs/Qt), airway resistance, respiratory tissue damping, end-expiratory lung volume, lung clearance index and lung aeration by chest electrical impedance tomography. Measurements were performed at the end of each protocol stage. Ventilation modality had no effect on any respiratory mechanical parameter. Adequate gas exchange was provided by FCV, similar to PRVC, with sufficient CO₂ elimination both in healthy and surfactant-depleted lungs (39.46 ± 7.2 mmHg and 46.2 ± 11.4 mmHg for FCV; 36.0 ± 4.1 and 39.5 ± 4.9 mmHg, for PRVC, respectively). Somewhat lower PaO₂/FiO₂ and higher Qs/Qt were observed in healthy and surfactant depleted lungs during FCV compared to PRVC (p < 0.05, for all). Compared to PRVC, lung aeration was significantly elevated, particularly in the ventral dependent zones during FCV (p < 0.05), but this difference was not evidenced in injured lungs. Somewhat lower oxygenation and higher shunt ratio was observed during FCV, nevertheless lung aeration improved and adequate gas exchange was ensured. Therefore, in the absence of major differences in respiratory mechanics and lung volumes, FCV may be considered as an alternative in ventilation therapy of pediatric patients with healthy and injured lungs.