Patient-ventilator Interaction During NIV With Helmet: a Comparison Between PSV and the New NIV NPS Software

Patient-ventilator Interaction During NIV With Helmet: a Comparison Between PSV and the New NIV NPS Software

Patient-ventilator Interaction During NIV With Helmet: a Comparison Between PSV and the New NIV NPS Software

The goal of this clinical trial is to evaluate if neural pressure support ventilation is able to improve patient-ventilator synchrony, in ICU patients undergoing non-invasive ventilation (NIV). The main question it aims to answer is: • Is neural pressure support ventilation better than the pressure support ventilation with respect to patient-ventilator synchrony during helmet NIV? Researchers will compare neural pressure support ventilation versus pressure support ventilation (Gold standard assisted mode in Europe) to see if the new mode improve patient-ventilator synchrony.

Non-Invasive Ventilation (NIV) has found many different uses in clinical settings, shortening intubation times and preventing orotracheal intubation. NIV success is highly affected by patient comfort and patient-ventilator synchrony. The helmet is one of the most comfortable interfaces, even if synchrony is low due to dead space. The use of Neurally Adjusted Ventilatory Assist (NAVA), in which the Electrical Activity of the Diaphragm (EAdi) drives the ventilator, has shown improvement in comfort and synchrony but still some limitation with helmet, due to the long pressurization time. Pressure-Support Ventilation (PSV) is still the most used and diffused assisted mode in Europe due to its simplicity and effectiveness in helmet-NIV. The aim of this study is to test a new ventilation software called Neural Pressure Support Ventilation (nPSV), which merges the rapid pressurization of PSV along with the EAdi trigger, onto a population of 24 critical care patients ventilated with a helmet NIV.

Patients will be ventilated in nPSV or PSV (according to randomization) and then, after an initial period of ventilation, they will be ventilated with the other technique. Ventilation then will be optimized by an expert and the two modes of ventilation will be repeated in succession.

Synchrony time [Timesych]: time frame during which both the ventilator and the neural patient inspiratory time are in the inspiratory phase (s)

Asynchrony Index (AI): ratio between the number of ineffective efforts, auto-triggers and double triggers and the neural respiratory rate plus auto-triggers (percentage)

Inclusion Criteria: Adult patients (>18aa) Non Invasive Ventilation with helmet NG tubing for clinical use in position Invasive arterial monitoring for clinical use in position Exclusion Criteria: Unable to express consent Expected NIV < 24hrs Gastric-esophageal surgery in the preceding 12 months Upper-GI bleeding in the last 30 days History of esophageal varices Recent trauma or facial surgery Haemodinamic instability even a after liquid infusion (need of at least dopamine >5 γ/kg/min or norephinephrine >0.1 γ/kg min to obtain systolic pressure >90 mmHg) Core temperature >30C° Coagulation disorders (INR > 1.5 and/or aPTT >44 sec)

Evans TW. International Consensus Conferences in Intensive Care Medicine: non-invasive positive pressure ventilation in acute respiratory failure. Organised jointly by the American Thoracic Society, the European Respiratory Society, the European Society of Intensive Care Medicine, and the Societe de Reanimation de Langue Francaise, and approved by the ATS Board of Directors, December 2000. Intensive Care Med. 2001 Jan;27(1):166-78. doi: 10.1007/s001340000721. No abstract available.

Squadrone E, Frigerio P, Fogliati C, Gregoretti C, Conti G, Antonelli M, Costa R, Baiardi P, Navalesi P. Noninvasive vs invasive ventilation in COPD patients with severe acute respiratory failure deemed to require ventilatory assistance. Intensive Care Med. 2004 Jul;30(7):1303-10. doi: 10.1007/s00134-004-2320-7. Epub 2004 Jun 12.

Vignaux L, Vargas F, Roeseler J, Tassaux D, Thille AW, Kossowsky MP, Brochard L, Jolliet P. Patient-ventilator asynchrony during non-invasive ventilation for acute respiratory failure: a multicenter study. Intensive Care Med. 2009 May;35(5):840-6. doi: 10.1007/s00134-009-1416-5. Epub 2009 Jan 29.

Navalesi P, Costa R, Ceriana P, Carlucci A, Prinianakis G, Antonelli M, Conti G, Nava S. Non-invasive ventilation in chronic obstructive pulmonary disease patients: helmet versus facial mask. Intensive Care Med. 2007 Jan;33(1):74-81. doi: 10.1007/s00134-006-0391-3. Epub 2006 Oct 13.

Colombo D, Cammarota G, Bergamaschi V, De Lucia M, Corte FD, Navalesi P. Physiologic response to varying levels of pressure support and neurally adjusted ventilatory assist in patients with acute respiratory failure. Intensive Care Med. 2008 Nov;34(11):2010-8. doi: 10.1007/s00134-008-1208-3. Epub 2008 Jul 16.

Muttini S, Villani PG, Trimarco R, Bellani G, Grasselli G, Patroniti N. Relation between peak and integral of the diaphragm electromyographic activity at different levels of support during weaning from mechanical ventilation: a physiologic study. J Crit Care. 2015 Feb;30(1):7-12. doi: 10.1016/j.jcrc.2014.08.013. Epub 2014 Aug 28.