Session Webcast
PROTEOMICS IN ACUTE RESPIRATORY DISTRESS SYNDROME
MECHANICAL POWER: TARGET IN PREVENTING VILI
Video on Demand
USING TIME-BASED CAPNOGRAPHY TO DETECT INEFFECTIVE TRIGGERING IN MECHANICALLY VENTILATED CHILDREN: A PROOF-OF-CONCEPT STUDY
Abstract
Background
The occurrence of patient-ventilator-asynchrony (PVA) is associated with prolonged duration of mechanical ventilation, especially ineffective triggering. This suggests that real-time monitoring PVA should be developed to improve patient outcome.
Objectives
We propose that ineffective triggering may be identified by a negative deflection in the time-based capnogram. We tested that time-based capnography can be used to detect ineffective triggering and to develop an automated detection algorithm.
Methods
Patients underwent a recording of the ventilator waveforms, electrical activity of the diaphragm and capnogram waveform. Five minutes of the recording were used to identify ineffective triggering events. Ten minutes were used to validate to algorithm.
Results
The waveforms in combination with EMG tracings of the diaphragm identified 161 ineffective triggering events (4.2%) in 3823 breaths. This yielded a total sensitivity of 64% and specificity of 98.6%. Subgroup analysis of the group with ineffective triggering events with a flow > 0 L/min showed a sensitivity of 94.4% and a specificity of 98.4 In total 10800 breaths were used to validate capnogram based ineffective triggering algorithm. This results in a sensitivity and specificity of 95.3% and 99.9%.
Conclusion
Capnography can be used to detect PVA especially those concerning ineffective triggering. Because capnography is readily available in the PICU and is non-invasive this method may have important implications for both clinical and research purposes.
OLA STRATEGY LOWERS MORTALITY OF VENTILATED ARDS PATIENTS, ALTHOUGH THE EFFECT DEPENDS ON LUNG RECRUITMENT (PAO2/FIO2) AND MECHANICAL POWER: SYSTEMATIC REVIEW AND META-ANALYSIS
Abstract
Background
Mechanical ventilation (MV) can produce VILI. “Open Lung Approach” (OLA) strategies could improve survival, but evidence is conflictive.
Objectives
Compare the clinical effectof a MV strategy aimed at maximising lung recruitmentin ARDS patients. And to see if this effect depends on the mechanical power (MP) transmitted to the lungs.
Methods
Systematic review and meta-analysis. We included RCTs of ARDS patients which included MV strategies aimed at maximising the lung recruited volume using high PEEP (OLA-group), versus standard strategies (CONTROL-group). RCTs of prone position or HFV were excluded. We used GRADE methodology. Random effects model was used to evaluate OLA strategy effect on 28 day Relative Risk of mortality (RR). A meta-regression was also performed with 3 candidate variables: PEEP level in OLA-group, recruitment (PaO2/FiO2) achieved in CONTROL-group, and relative MP/kg. The “best fit” model was the one with the minimum Akaike Information Criteria.
Results
Twelve RCTs (4,761 patients) were included. Mortality was significantly lower in OLA-group: RR = 0.86 (95% CI = 0.74 to 0.99; RE model). Quality of evidence was downgraded and there was no evidence of publication bias. The best model included PaO2/FiO2 of CONTROL-group and relative MP/kg. It shows that the effect of OLA disappears when the CONTROL-group has a PaO2/FiO2 > 170, and when relative MP/kg >= 1.
Conclusion
MV with OLA strategy improves mortality in ARDS patients. The effect vanishes when patients are already well recruited or when OLA strategy produces a higher energy transmission to the lungs.
Video on Demand
EXTUBATION AFTER SPONTANEOUS BREATHING TRIAL WITH AUTOMATIC TUBE COMPENSATION (ATC) VS PRESSURE SUPPORT.
Abstract
Background
There is evidence that tolerance to spontaneous breathing trial (SBT) increases the success in withdrawing mechanical ventilation. Different strategies are employed for STB like: “Pressure Support Ventilation” (PSV) or “Automatic Tube Compensation” (ATC).
Objectives
To evaluate the success of extubation after SBT with ATC versus PSV of 8 cm H2O.
Methods
Randomized control trial. Inclusion criteria: mechanically ventilated patients for more than 24 hours that meet criteria for SBT. One-hour SBT is done, with CPAP of 5 cm H2O and ATC, or CPAP of 5 cm water and PSV. Patients who passed the SBT were extubated. The primary outcome was the ability to breathe without assistance within 48 hours after extubation. The frequency/tidal volume ratio, the P.01 and maximum inspiratory force (NIF) at the beginning of the SBT and before extubation as predictors of success were also measured.
Results
SBT was performed in 91 patients (47 with PS and 44 with ATC) and failed in six patients (6,6%). Extubation failed in 13 patients: 7/41 in the ATC group (17,1%) and 6/44 in the PS group (13,6%) (OR: 1,3 CLC95% 0,40-4,3; p=66). For each unit of breathing frequency/tidal volume/kg ratio the OR of the success is multiplied by 0,744 (CL95%: 0,56-0,987; p=0,040). Maximum inspiratory force or P.01 were not found as predictors of extubation success
Conclusion
SBT with ATC is useful for extubation, being as effective in predicting extubation success as the SBT with Pressure Support.
Presentation files
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EXTUBATION AFTER SPONTANEOUS BREATHING TRIAL WITH AUTOMATIC TUBE (1) 20.06.2019 16:10
Video on Demand
CLINICAL CHALLENGES AND LIMITATIONS OF THE CURRENT PEDIATRIC ACUTE RESPIRATORY DISTRESS SYNDROME DEFINITION
Abstract
Background
The Pediatric Acute Lung Injury Consensus Conference (PALICC) definition is currently used to diagnose pediatric acute respiratory distress syndrome (PARDS).
Objectives
We aimed to determine the clinical characteristics of patients identified to have PARDS and evaluate whether these patients could be better defined by alternative diagnoses.
Methods
We screened all pediatric intensive care unit (PICU) admissions daily over a year (2018). Patients who fulfilled the PALICC definition were prospectively recruited. We interrogated the clinical history and course of illness to identify factors which (1) made the diagnosis of PARDS unlikely or (2) altered the course of illness in patients with PARDS.
Results
Over the one-year period, there were 594 PICU admissions. 47/594(8%) patients were identified to have PARDS. Despite meeting the PALICC criteria, 5/47(11%) patients were suspected to have alternate diagnosis to PARDS [congestive cardiac failure/ fluid overload (despite normal 2D-echocardiography), pulmonary hypertension, pulmonary hemorrhage, lung contusion with drained hemopneumothorax]. 28/47(60%) patients had underlying comorbidities, of which 8/47(17%) were likely to confound the evolution of PARDS – these were patients who had underlying pulmonary hemosiderosis, pulmonary lymphangiectasia, restrictive lung disease and immunodeficiency. Together, these patients were more likely to develop severe PARDS [5/13(38%) vs 3/34(9%); p=0.028], and had increased mortality [4/13(30%) vs 3/34(9%); p=0.080] compared to the general PARDS cohort, though it was not statistically significant.
Conclusion
A significant proportion of patients fulfilling criteria for PARDS are suspected to have alternate diagnoses (false positives) or underlying diseases that potentially alter the course of illness.