Objective: During pressure support ventilation, ventilator inspiration ends when inspiratory flow drops to a given percentage of the peak inspiratory flow cycling-off criteria. This study evaluated the effect of two different cycling-off criteria on breathing pattern, respiratory effort, and gas exchange in patients with chronic obstructive pulmonary disease.
Design: Clinical study.
Patients: Thirteen mechanically ventilated patients with acute exacerbation of chronic obstructive pulmonary disease primarily due to pneumonia (PaO2/FIO2 291 +/- 114 mm Hg, PaCO2 53 +/- 19 mm Hg).
Interventions: Two cycling-off criteria (5% and 40% of the peak inspiratory flow) at two levels of pressure support (5 and 15 cm H2O) with and without the application of an external positive end-expiratory pressure (6 and 0 cm H2O) were applied. Measurement Patient-ventilator time delay of cycling-off was computed as the difference between the end of inspiratory flow and the lowest value of inspiratory esophageal pressure. Inspiratory effort was estimated by computing the work of breathing, the pressure time product partitioned into the total pressure time product, and the pressure time product due to the dynamic intrinsic positive end-expiratory pressure.
Results: At 5 and 15 cm H2O of pressure support ventilation, the cycling-off criteria 40% significantly reduced the patient-ventilator time delay of cycling-off from 0.40 +/- 0.20 secs to 0.29 +/- 0.16 secs and from 0.93 +/- 0.50 secs to 0.52 +/- 0.25 secs, respectively; the dynamic intrinsic positive end-expiratory pressure from 3.9 +/- 1.8 cm H2O to 3.1 +/- 2.1 cm H2O and from 2.4 +/- 2.0 cm H2O to 1.7 +/- 1.4 cm H2O, respectively; and the pressure time product due to the dynamic intrinsic positive end-expiratory pressure. At 5 cm H2O of pressure support, the cycling-off criteria 40% significantly reduced the tidal volume and the inspiratory effort. The modification of cycling-off criteria did not affect the gas exchange.
Conclusion: The modification of cycling-off criteria may have a beneficial effect on reducing the dynamic hyperinflation and inspiratory effort in chronic obstructive pulmonary disease patients, especially at low levels of pressure support.
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http://dx.doi.org/10.1097/01.CCM.0000287594.80110.34 | DOI Listing |
Front Med (Lausanne)
November 2021
Jiangsu Provincial Key Laboratory of Critical Care Medicine, Department of Critical Care Medicine, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.
Patient-ventilator asynchrony is common during pressure support ventilation (PSV) because of the constant cycling-off criteria and variation of respiratory system mechanical properties in individual patients. Automatic adjustment of inspiratory triggers and cycling-off criteria based on waveforms might be a useful tool to improve patient-ventilator asynchrony during PSV. Twenty-four patients were enrolled and were ventilated using PSV with different cycling-off criteria of 10% (PS), 30% (PS), 50% (PS), and automatic adjustment PSV (PS).
View Article and Find Full Text PDFWorld J Pediatr
August 2015
Neonatal Intensive Care Unit, Mansoura University Children's Hospital, Mansoura, Egypt,
Background: Nasal continuous positive airway pressure (NCPAP) is frequently used in preterm infants. However, there is no consensus on when and how to wean them from NCPAP.
Data Sources: Based on recent publications, we have reviewed the criteria of readiness-to-wean and factors affecting weaning success.
J Bras Pneumol
January 2015
Department of Pulmonology, Hospital das Clínicas, School of Medicine, University of São Paulo, São Paulo, Brazil.
Objective: Discomfort and noncompliance with noninvasive ventilation (NIV) interfaces are obstacles to NIV success. Total face masks (TFMs) are considered to be a very comfortable NIV interface. However, due to their large internal volume and consequent increased CO2 rebreathing, their orifices allow proximal leaks to enhance CO2 elimination.
View Article and Find Full Text PDFArch Dis Child Fetal Neonatal Ed
September 2014
Department of Neonatology, Canberra Hospital, Garran, Australian Capital Territory, Australia Australian National University Medical School, Canberra, Australian Capital Territory, Australia.
Introduction: In our previous randomised controlled trial (RCT), we have shown in preterm babies (PBs) <30 weeks gestation that CeasIng Cpap At standarD criteriA (CICADA (method 1)) compared with cycling off continuous positive airway pressure (CPAP) gradually (method 2) or cycling off CPAP gradually with low flow air/oxygen during periods off CPAP (method 3) reduces CPAP cessation time in PBs <30 weeks gestation.
Method: This retrospective study reviewed weight gain, time to reach full feeds and time to cease caffeine in PBs previously enrolled in the RCT.
Results: Data were collected from 162 of the 177 PBs, and there was no significant difference in the projected weight gain between the three methods.
J Crit Care
June 2014
Università degli Studi di Milano, Dipartimento di fisiopatologia medico-chirurgica e dei trapianti, Milano, Italia.
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