Respiratory dynamics and dead space to tidal volume ratio of volume-controlled versus pressure-controlled ventilation during prolonged gynecological laparoscopic surgery

2016 ◽  
Vol 31 (9) ◽  
pp. 3605-3613 ◽  
Author(s):  
Ming Lian ◽  
Xiao Zhao ◽  
Hong Wang ◽  
Lianhua Chen ◽  
Shitong Li
Keyword(s):  
Laparoscopic Surgery ◽  
Tidal Volume ◽  
Dead Space ◽  
Volume Ratio ◽  
Controlled Ventilation ◽  
Pressure Controlled Ventilation ◽  
Respiratory Dynamics ◽  
Volume Controlled ◽  
Pressure Controlled

scholarly journals Combined Ventilation Of Two Subjects With A Single Mechanical Ventilator Using A New Medical Device: An In Vitro Study

2021 ◽  
Author(s):  
Ignacio Lugones ◽  
Matias Ramos ◽  
Maria Fernanda Biancolini ◽  
Roberto Eduardo Orofino Giambastiani
Keyword(s):  
Tidal Volume ◽  
Lung Compliance ◽  
Positive End Expiratory Pressure ◽  
Controlled Ventilation ◽  
Pressure Controlled Ventilation ◽  
Volume Controlled Ventilation ◽  
Ventilation Modes ◽  
The Subject ◽  
Volume Controlled ◽  
Pressure Controlled

INTRODUCTION: The SARS-CoV2 pandemic has created a sudden lack of ventilators. DuplicAR® is a novel device that allows simultaneous and independent ventilation of two subjects with a single ventilator. The aims of this study are: a) to determine the efficacy of DuplicAR® to independently regulate the peak and positive-end expiratory pressures in each subject, both under pressure-controlled ventilation and volume-controlled ventilation, and b) to determine the ventilation mode in which DuplicAR® presents the best performance and safety. MATERIALS AND METHODS: Two test lungs are connected to a single ventilator using DuplicAR®. Three experimental stages are established: 1) two identical subjects, 2) two subjects with the same weight but different lung compliance, and 3) two subjects with different weight and lung compliance. In each stage, the test lungs are ventilated in two ventilation modes. The positive-end expiratory pressure requirements are increased successively in one of the subjects. The goal is to achieve a tidal volume of 7 ml/kg for each subject in all different stages through manipulation of the ventilator and the DuplicAR® controllers. RESULTS: DuplicAR® allows adequate ventilation of two subjects with different weight and/or lung compliance and/or PEEP requirements. This is achieved by adjusting the total tidal volume for both subjects (in volume-controlled ventilation) or the highest peak pressure needed (in pressure-controlled ventilation) along with the basal positive-end expiratory pressure on the ventilator, and simultaneously manipulating the DuplicAR® controllers to decrease the tidal volume or the peak pressure in the subject that needs less and/or to increase the positive-end expiratory pressure in the subject that needs more. While ventilatory goals can be achieved in any of the ventilation modes, DuplicAR® performs better in pressure-controlled ventilation, as changes experienced in the variables of one subject do not modify the other one. CONCLUSIONS: DuplicAR® is an effective tool to manage the peak inspiratory pressure and the positive-end expiratory pressure independently in two subjects connected to a single ventilator. The driving pressure can be adjusted to meet the requirements of subjects with different weight and lung compliance. Pressure-controlled ventilation has advantages over volume-controlled ventilation and is therefore the recommended ventilation mode.

Effect of Ventilatory Settings on Accuracy of Cardiac Output Measurement Using Partial CO2Rebreathing

2002 ◽  
Vol 96 (1) ◽  
pp. 96-102 ◽  
Author(s):  
Kazuya Tachibana ◽  
Hideaki Imanaka ◽  
Hiroshi Miyano ◽  
Muneyuki Takeuchi ◽  
Keiji Kumon ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Tidal Volume ◽  
Positive End Expiratory Pressure ◽  
Limits Of Agreement ◽  
Ventilatory Mode ◽  
Controlled Ventilation ◽  
Pressure Controlled Ventilation ◽  
Volume Controlled Ventilation ◽  
Volume Controlled ◽  
Pressure Controlled

Background Recently, a new device has been developed to measure cardiac output noninvasively using partial carbon dioxide (CO(2)) rebreathing. Because this technique uses CO(2) rebreathing, the authors suspected that ventilatory settings, such as tidal volume and ventilatory mode, would affect its accuracy: they conducted this study to investigate which parameters affect the accuracy of the measurement. Methods The authors enrolled 25 pharmacologically paralyzed adult post-cardiac surgery patients. They applied six ventilatory settings in random order: (1) volume-controlled ventilation with inspired tidal volume (V(T)) of 12 ml/kg; (2) volume-controlled ventilation with V(T) of 6 ml/kg; (3) pressure-controlled ventilation with V(T) of 12 ml/kg; (4) pressure-controlled ventilation with V(T) of 6 ml/kg; (5) inspired oxygen fraction of 1.0; and (6) high positive end-expiratory pressure. Then, they changed the maximum or minimum length of rebreathing loop with V(T) set at 12 ml/kg. After establishing steady-state conditions (15 min), they measured cardiac output using CO(2) rebreathing and thermodilution via a pulmonary artery catheter. Finally, they repeated the measurements during pressure support ventilation, when the patients had restored spontaneous breathing. The correlation between two methods was evaluated with linear regression and Bland-Altman analysis. Results When VT was set at 12 ml/kg, cardiac output with the CO(2) rebreathing technique correlated moderately with that measured by thermodilution (y = 1.02x, R = 0.63; bias, 0.28 l/min; limits of agreement, -1.78 to +2.34 l/min), regardless of ventilatory mode, oxygen concentration, or positive end-expiratory pressure. However, at a lower VT of 6 ml/kg, the CO(2) rebreathing technique underestimated cardiac out-put compared with thermodilution (y = 0.70x; R = 0.70; bias, -1.66 l/min; limits of agreement, -3.90 to +0.58 l/min). When the loop was fully retracted, the CO(2) rebreathing technique overestimated cardiac output. Conclusions Although cardiac output was underreported at small VT values, cardiac output measured by the CO(2) rebreathing technique correlates fairly with that measured by the thermodilution method.

scholarly journals Combined Ventilation of Two Subjects with a Single Mechanical Ventilator Using a New Medical Device: An In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Ignacio Lugones ◽  
Matías Ramos ◽  
María Fernanda Biancolini ◽  
Roberto Orofino Giambastiani
Keyword(s):  
Tidal Volume ◽  
Ventilation Mode ◽  
Positive End Expiratory Pressure ◽  
Controlled Ventilation ◽  
Pressure Controlled Ventilation ◽  
Volume Controlled Ventilation ◽  
Ventilation Modes ◽  
The Subject ◽  
Volume Controlled ◽  
Pressure Controlled

Introduction. The SARS-CoV-2 pandemic has created a sudden lack of ventilators. DuplicARⓇ is a novel device that allows simultaneous and independent ventilation of two subjects with a single ventilator. The aims of this study are (a) to determine the efficacy of DuplicARⓇ to independently regulate the peak and positive-end expiratory pressures in each subject, both under pressure-controlled ventilation and volume-controlled ventilation and (b) to determine the ventilation mode in which DuplicARⓇ presents the best performance and safety. Materials and Methods. Two test lungs are connected to a single ventilator using DuplicARⓇ. Three experimental stages are established: (1) two identical subjects, (2) two subjects with the same weight but different lung compliance, and (3) two subjects with different weights and lung compliances. In each stage, the test lungs are ventilated in two ventilation modes. The positive-end expiratory pressure requirements are increased successively in one of the subjects. The goal is to achieve a tidal volume of 7 ml/kg for each subject in all different stages through manipulation of the ventilator and the DuplicARⓇ controllers. Results. DuplicARⓇ allows adequate ventilation of two subjects with different weights and/or lung compliances and/or PEEP requirements. This is achieved by adjusting the total tidal volume for both subjects (in volume-controlled ventilation) or the highest peak pressure needed (in pressure-controlled ventilation) along with the basal positive-end expiratory pressure on the ventilator and simultaneously manipulating the DuplicARⓇ controllers to decrease the tidal volume or the peak pressure in the subject that needs less and/or to increase the positive-end expiratory pressure in the subject that needs more. While ventilatory goals can be achieved in any of the ventilation modes, DuplicARⓇ performs better in pressure-controlled ventilation, as changes experienced in the variables of one subject do not modify the other one. Conclusions. DuplicARⓇ is an effective tool to manage the peak inspiratory pressure and the positive-end expiratory pressure independently in two subjects connected to a single ventilator. The driving pressure can be adjusted to meet the requirements of subjects with different weights and lung compliances. Pressure-controlled ventilation has advantages over volume-controlled ventilation and is therefore the recommended ventilation mode.

scholarly journals Comparison of Pressure-Controlled Ventilation with Volume Guarantee and Volume-Controlled Ventilation mode in Patients under Laparoscopic Surgery: A Meta-Analysis of Randomized Controlled Trials

2019 ◽  
Author(s):  
Xiaoxiao Li ◽  
Xueli Lv ◽  
Zhenfei Jiang ◽  
Xinrui Nie ◽  
Su Liu
Keyword(s):  
Laparoscopic Surgery ◽  
Peak Pressure ◽  
Meta Analysis ◽  
Dynamic Compliance ◽  
Controlled Ventilation ◽  
Pressure Controlled Ventilation ◽  
Co2 Insufflation ◽  
Volume Controlled Ventilation ◽  
Volume Controlled ◽  
Pressure Controlled

Abstract Background：In traditional Volume-Controlled Ventilation (VCV) mode, the creation of pneumoperitoneum during laparoscopic surgery may lead to Ventilator-Associated Lung Injury (VALI). Pressure-Controlled Ventilation with Volume Guarantee (PCV-VG) mode ensures providing adequate oxygen supply to patients while reducing the risk of lung injury. Methods：Eligible randomized clinical trials (RCTs) were searched in Medline, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), Sino Med, China National Knowledge Infrastructure (CNKI) and Wan-Fang MED without language restriction up to March 2019. The primary outcome of this meta-analysis was airway peak pressure (Ppeak) at 30, 60 or 90 mins after complete CO2 insufflation. This meta-analysis was followed the recommendations of the PRISMA statement. Results：Finally, 9 articles were included. The Ppeak in the PCV-VG group was lower than that in the VCV group, and the difference was statistically significant at 30mins [Mean Difference (MD)= -3.55, 95% Confidence Interval (CI)= -5.13 to -1.98, I2=83%], 60mins [MD= -5.76, 95%CI= -8.15-3.36, I2=93%], 90 mins [MD= -4.59, 95%CI= -5.43-3.74, I2=30%] after complete CO2 insufflation. Meanwhile, PCV-VG mode could effectively reduce airway mean pressure (Pmean) and improve dynamic compliance (Cdyn) of patients after complete CO2 insufflation in laparoscopic surgery compared to VCV mode. However, no significant difference was found in PetCO2, HR, MAP, PH, PaO2, and PaCO2 between the two-ventilation modes. Conclusions: PCV-VG mode are superior to VCV mode in providing adequate oxygenation at lower airway peak pressure and greater dynamic compliance in patients under laparoscopic surgery.

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