scholarly journals Assessment of Fluid Responsiveness After Tidal Volume Challenge During Pressure-Controlled Ventilation Volume Guaranteed: An observational study

2020 ◽  
Author(s):  
Yu Jiang ◽  
Lingling Jiang ◽  
Jun Hu ◽  
Ye Zhang
Keyword(s):  
Body Weight ◽  
Tidal Volume ◽  
Fluid Responsiveness ◽  
Transient Increase ◽  
Anesthesia Induction ◽  
Predicted Body Weight ◽  
Controlled Ventilation ◽  
Pressure Controlled Ventilation ◽  
Pressure Controlled ◽  
Volume Challenge

Abstract Background: The reliability of pulse pressure variation (PPV) and stroke volume variation (SVV) to predict fluid responsiveness have not previously been established when using pressure-controlled ventilation-volume guaranteed (PCV-VG) mode. We hypothesized that with a transient increase in tidal volume from 6 to 8 mL/kg of predicted body weight (PBW), which we reference as the “tidal volume challenge (TVC)”, the changes to PPV and SVV will be an indicator of fluid responsiveness.Methods: The patients were first ventilated with a tidal volume of (Vt) 6 mL/kg of predicted body weight (PBW) using PCV-VG. Following intravenous anesthesia induction, PPV6 and SVV6 were recorded, then the TVC was performed, which increased Vt from 6 mL/kg to 8 mL/kg PBW for 1 minute and PPV8 and SVV8 were recorded again. The changes in value of PPV and SVV (ΔPPV6-8 and ΔSVV6-8) were calculated after TVC. Following the minute of TVC, the tidal volume was returned to 6 ml/kg PBW for the fluid challenge (FC), a colloid infusion of 6ml/kg PBW for 20 minutes. Patients were classified as responders if there was an increase in cardiac index (CI) of more than 15% after FC, otherwise the patients were identified as non-responders. Eligible patients were divided into groups of responders or non-responders.Results: 37 patients were classified as responders and 44 were non-responders. PPV6 and SVV6 could not predict the fluid responsiveness, while PPV8 and SVV8 could predict the fluid responsiveness when using PCV-VG mode. The changes in value of PPV and SVV after TVC (ΔPPV6-8 and ΔSVV6-8) identified true fluid responders with the highest sensitivity and specificity in the above variables, which predicted fluid responsiveness with the area under the receiver operating characteristic curves (AUCs) (95% CIs) being 0.96 (0.93-1.00) and 0.98 (0.96-1.00), respectively. No significant difference was found when comparing the AUCs of ΔPPV6-8 and ΔSVV6-8 (P > 0.05). Linear correlation was represented between the change value of CI after FC and the change value of SVV or PPV after TVC (r = 0.68; P < 0.0001 and r = 0.77; P < 0.0001, respectively).Conclusions: A transient increase in tidal volume, which we reference as the “tidal volume challenge (TVC)” could enhance the predictive value of PPV and SVV for the evaluation of fluid responsiveness in patients under ventilation with PCV-VG.Trial registration: Chinese Clinical Trial Registry (ChiCTR2000028995). Prospectively registered on 11 January 2020. http://www.medresman.org.

Adaptive Support Ventilation May Deliver Unwanted Respiratory Rate–Tidal Volume Combinations in Patients with Acute Lung Injury Ventilated According to an Open Lung Concept

2011 ◽  
Vol 114 (5) ◽  
pp. 1138-1143 ◽  
Author(s):  
Dave A. Dongelmans ◽  
Frederique Paulus ◽  
Denise P. Veelo ◽  
Jan M. Binnekade ◽  
Margreeth B. Vroom ◽  
...  
Keyword(s):  
Body Weight ◽  
Respiratory Rate ◽  
Predicted Body Weight ◽  
Adaptive Support Ventilation ◽  
Support Ventilation ◽  
Controlled Ventilation ◽  
Open Lung ◽  
Pressure Controlled Ventilation ◽  
Adaptive Support ◽  
Pressure Controlled

Background With adaptive support ventilation, respiratory rate and tidal volume (V(T)) are a function of the Otis least work of breathing formula. We hypothesized that adaptive support ventilation in an open lung ventilator strategy would deliver higher V(T)s to patients with acute lung injury. Methods Patients with acute lung injury were ventilated according to a local guideline advising the use of lower V(T) (6-8 ml/kg predicted body weight), high concentrations of positive end-expiratory pressure, and recruitment maneuvers. Ventilation parameters were recorded when the ventilator was switched to adaptive support ventilation, and after recruitment maneuvers. If V(T) increased more than 8 ml/kg predicted body weight, airway pressure was limited to correct for the rise of V(T). Results Ten patients with a mean (±SD) Pao(2)/Fio(2) of 171 ± 86 mmHg were included. After a switch from pressure-controlled ventilation to adaptive support ventilation, respiratory rate declined (from 31 ± 5 to 21 ± 6 breaths/min; difference = 10 breaths/min, 95% CI 3-17 breaths/min, P = 0.008) and V(T) increased (from 6.5 ± 0.8 to 9.0 ± 1.6 ml/kg predicted body weight; difference = 2.5 ml, 95% CI 0.4-4.6 ml/kg predicted body weight, P = 0.02). Pressure limitation corrected for the rise of V(T), but minute ventilation declined, forcing the user to switch back to pressure-controlled ventilation. Conclusions Adaptive support ventilation, compared with pressure-controlled ventilation in an open lung strategy setting, delivers a lower respiratory rate-higher V(T) combination. Pressure limitation does correct for the rise of V(T), but leads to a decline in minute ventilation.

TIDAL-VOLUME VARIANCE FOR ASSESSMENT OF SEDATION IN PATIENTS WITH PRESSURE-CONTROLLED VENTILATION

2004 ◽  
Vol 32 (Supplement) ◽  
pp. A110
Author(s):  
Wolfgang Huber ◽  
Friedemann Meiswinkel ◽  
Andreas Umgelter ◽  
Florian Eckel ◽  
Michael Hennig ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Controlled Ventilation ◽  
Pressure Controlled Ventilation ◽  
Pressure Controlled

Fluid responsiveness in patients under mechanical ventilation and low tidal volume ventilation through the pulse pressure variation after tidal volume challenge in the post-operative cardiac surgery

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
D F C Azevedo ◽  
R M Viera De Melo ◽  
A C Cunha ◽  
L G S Brito ◽  
T Viana ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Tidal Volume ◽  
Fluid Responsiveness ◽  
Postoperative Period ◽  
Pulse Pressure ◽  
Pressure Variation ◽  
Predict Fluid Responsiveness ◽  
Predicted Body Weight ◽  
Volume Challenge ◽  
Excellent Accuracy

Abstract Background It is known that in the immediate postoperative period of cardiac surgery, strict control of hemodynamic variables and blood volume is necessary, since there is an imbalance between oxygen supply and consumption. Thus, the present study seeks to validate methods previously used in different clinical situations to predict fluid responsiveness, in the current scenario of the immediate postoperative period of cardiac surgery. Purpose To evaluate the influence of “tidal volume challenge” from 6 ml / kg to 8 ml / kg of the predicted body weight (PBW) in conjunction with the end expiratory occlusion test (EEOT) in the variation of pulse pressure to predict fluid responsiveness in the immediate postoperative period of cardiac surgery. Methodology This prospective study included 30 patients after cardiac surgery. Hemodynamic and ventilatory parameters were initially recorded in mechanical ventilation at 6 ml/kg and after tidial volume challenge and with the EEOT at 8 ml/kg of predicted body weight (PBW). After recorded the intervention data, there was a return to ventilation at 6 ml/kg and a saline infusion of 500 ml was performed for 15 minutes. Fluid responsiveness was defined for patients who had an increase of 10% or more in velocity time integral (VTI) by echocardiogram after volume expansion compared to baseline value. Multivariate analysis was used to identify independent predictors of fluid response status. Sensitivity and specificity analyzes were performed to determine the predictive precision of each parameter. Results The main result of our study is that, when the tidal volume is increased from 6 to 8 ml/kg of PBW, the relative increase in pulse pressure variation (%ΔPPV6–8) predicts with excellent accuracy responsiveness to fluids with cut-off values of 18.3%, with sensitivity of 92.9% and specificity of 84% (P=0.019). Although changing PPV6, EEOT6 and EEOT8 are not reliable in predicting fluid responsiveness, they still require additional calculations. PPV8 also discriminates between responders and non-responders; however, with sensitivity (78.6%) and specificity (66.6%) when the value found in the PPV8 is up 8.5, but without statistical significance (figure). Conclusion The challenge of tidal volume and its influence on the ΔPP variation has excellent accuracy to predict fluid responsiveness in the immediate postoperative period of cardiac surgery. EEOT did not present good accuracy to predict fluid responsiveness in patients in the immediate postoperative period of cardiac surgery. FUNDunding Acknowledgement Type of funding sources: None.

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.

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