Reliability and limits of transport-ventilators to safely ventilate severe patients in special surge situations

Background Intensive Care Units (ICU) have sometimes been overwhelmed by the surge of COVID-19 patients. Extending ICU capacity can be limited by the lack of air and oxygen pressure sources available. Transport ventilators requiring only one O2 source may be used in such places. Objective To evaluate the performances of four transport ventilators and an ICU ventilator in simulated severe respiratory conditions. Materials and methods Two pneumatic transport ventilators, (Oxylog 3000, Draeger; Osiris 3, Air Liquide Medical Systems), two turbine transport ventilators (Elisee 350, ResMed; Monnal T60, Air Liquide Medical Systems) and an ICU ventilator (Engström Carestation—GE Healthcare) were evaluated on a Michigan test lung. We tested each ventilator with different set volumes (Vtset = 350, 450, 550 ml) and compliances (20 or 50 ml/cmH2O) and a resistance of 15 cmH2O/l/s based on values described in COVID-19 Acute Respiratory Distress Syndrome. Volume error (percentage of Vtset) with P0.1 of 4 cmH2O and trigger delay during assist-control ventilation simulating spontaneous breathing activity with P0.1 of 4 cmH2O and 8 cmH2O were measured. Results Grouping all conditions, the volume error was 2.9 ± 2.2% for Engström Carestation; 3.6 ± 3.9% for Osiris 3; 2.5 ± 2.1% for Oxylog 3000; 5.4 ± 2.7% for Monnal T60 and 8.8 ± 4.8% for Elisee 350. Grouping all conditions (P0.1 of 4 cmH2O and 8 cmH2O), trigger delay was 50 ± 11 ms, 71 ± 8 ms, 132 ± 22 ms, 60 ± 12 and 67 ± 6 ms for Engström Carestation, Osiris 3, Oxylog 3000, Monnal T60 and Elisee 350, respectively. Conclusions In surge situations such as COVID-19 pandemic, transport ventilators may be used to accurately control delivered volumes in locations, where only oxygen pressure supply is available. Performances regarding triggering function are acceptable for three out of the four transport ventilators tested.

Reliability and limits of transport-ventilators to safely ventilate severe patients in special surge situations

BackgroundSeveral Intensive Care Units (ICU) have been overwhelmed by the surge of COVID-19 patients thus necessitating to extend ventilation capacity outside the ICU where air and oxygen pressure are not always available. Transport ventilators requiring only O2 source may be used to deliver volume-controlled ventilation.ObjectiveTo evaluate the performances of four transport ventilators compared to an ICU ventilator simulating severe respiratory conditions.Materials and methodsTwo pneumatic transport ventilators, (Oxylog 3000, Draeger; Osiris 3, Air Liquide Medical Systems) and two turbine transport ventilators (Elisee 350, ResMed; Monnal T60, Air Liquide Medical Systems) were compared to an ICU ventilator (Engström Carestation – GE Healthcare) using a Michigan training test lung. We tested each ventilator with different set volumes Vtset (350, 450, 550 ml) and different compliances (20 or 50 ml/cmH2O) and a resistance of 15 cmH2 0/L/sec based on values recently described in COVID-19 Acute Respiratory Distress Syndrome. Volume error was measured, as well as the trigger time delay during assist-control ventilation simulating spontaneous breathing activity with a P0.1 of 4 cmH20.ResultsGrouping all conditions, the volume error was 2.9 ± 2.2 % for Engström Carestation; 3.6 ± 3.9 % for Osiris 3; 2.5 ± 2.1 % for Oxylog 3000; 5.4 ± 2.7 % for Monnal T60 and 8.8 ± 4.8 % for Elisee 350. Grouping all conditions, trigger delay was 42 ± 4 ms, 65 ± 5 ms, 151 ± 14 ms, 51 ± 6 and 64 ± 5 ms for Engström Carestation, Osiris 3, Oxylog 3000, Monnal T60 and Elisee 350, respectively.ConclusionsIn special surge situations such as COVID-19 pandemic, most transport ventilators may be used to safely deliver volume-controlled ventilation in locations where only oxygen pressure supply is available with acceptable volume accuracy. Performances regarding triggering function are generally acceptable but vary across ventilators.

Can lung ultrasound assist in the decision of weaning mechanically ventilated neonates?

Background Mechanical ventilation is widely used in neonates presenting with respiratory distress; however, it is not without complications. Early weaning of neonates is vital however the process of extubation is difficult to determine precisely. The use of lung ultrasound in neonates is recently accepted as a reliable tool in the assessment of several lung conditions. The aim of this study was to assess the use of lung ultrasound score as a quantitative method to assist in the decision of weaning mechanically ventilated neonates. Results The study was conducted on 40 neonates admitted to the NICU with different causes of respiratory distress needing respiratory support by mechanical ventilation. Lung ultrasound was performed using a linear superficial probe at least three times, at admission, before switching mechanical ventilation mode and before weaning. The initial lung ultrasound score for all patients was between 9 and 36 (mean 25 ± 6.97, median 26) with the 11 patients initiated on Sync. Intermittent ventilation (SIMV) showing significantly lower scores than those initiated on assist/control ventilation (ACV). Patients successfully switched from ACV to SIMV showed significantly lower scores than those who failed. Patients successfully weaned from SIMV showed significantly lower scores than those who failed. ROC analysis showed a cut-off score of ≤ 14 had 85% sensitivity and 100% specificity for a successful switch between ACV to SIMV. It also showed that a score ≤ 6 had 87.5% sensitivity and 100% specificity for successful extubation. Conclusion The use of quantitative lung ultrasound scores in assessment of mechanically ventilated neonates shows a great potential in aiding the process of weaning.