High-frequency oscillation and tracheal gas insufflation in patients with severe acute respiratory distress syndrome and traumatic brain injury: an interventional physiological study

In acute respiratory distress syndrome (ARDS), combined high-frequency oscillation (HFO) and tracheal gas insufflation (TGI) improves gas exchange compared with conventional mechanical ventilation (CMV). We evaluated the effect of HFO-TGI on PaO2/fractional inspired O2 (FiO2) and PaCO2, systemic hemodynamics, intracranial pressure (ICP), and cerebral perfusion pressure (CPP) in patients with traumatic brain injury (TBI) and concurrent severe ARDS

Nasal High Flow Oxygen in Respiratory Failure

High flow nasal cannula system or nasal high flow oxygen is an oxygen delivery device which administers heated, humidified high flow oxygen with concentrations from 21% to 100% and with a flow rate up to 60 L/min in adults. It generates many physiologic effects to respiratory system with a lot of clinical applications. Indeed, greater comfort and tolerance, more effective oxygenation, and improved breathing pattern with increased tidal volume and decreased respiratory rate and dyspnea has constantly been detected. Therefore, it can be used to improve cardiogenic pulmonary edema and hypoxemic respiratory failure of any cause, postoperatively, during post-extubation, as well as for palliative car

The effect of high frequency oscillatory ventilation combined with tracheal gas insufflation on extravascular lung water in patients with acute respiratory distress syndrome: a randomized, crossover, physiological study.

Purpose: High frequency oscillation combined with tracheal gas insufflation (HFO-TGI) improves oxygenation in patients with Acute Respiratory Distress Syndrome (ARDS). There is limited physiologic data regarding the effects of HFO-TGI on hemodynamics and pulmonary edema during ARDS. The aim of this study was to investigate the effect of HFO-TGI on extravascular lung water (EVLW). Materials and Methods: We conducted a prospective, randomized, crossover study. Consecutive eligible patients with ARDS received sessions of conventional mechanical ventilation (CMV) with recruitment maneuvers (RMs), followed by HFO-TGI with RMs, or vice versa. Each ventilatory technique was administered for 8 hours. The order of administration was randomly assigned. Arterial/central venous blood gas analysis and measurement of hemodynamic parameters and EVLW were performed at baseline and after each 8-hour period using the single-indicator thermodilution technique. Results: Twelve patients received 32 sessions. PaO2/FiO2 and respiratory system compliance were higher (p<0.001 for both), while EVLW indexed to predicted body weight (EVLWI) and oxygenation index were lower (p=0.021 and 0.029, respectively) in HFO-TGI compared with CMV. There was a significant correlation between PaO2/FiO2 improvement and EVLWI drop during HFO-TGI (Rs=-0.452, p= 0.009). Conclusions: HFO-TGI improves gas exchange and lung mechanics in ARDS, and potentially attenuates EVLW accumulation

The effect of mechanical ventilation with small tidal volumes and the effect of high frequency vertilation with or without the combination of tracheal gas insuflation, on pulmonary and cardiovascullar physiological variables in acute respiratory distess syndrome

In acute respiratory distress syndrome (ARDS), recruitment sessions of high-frequency oscillation (HFO) and tracheal gas insuflation (TGI) with short-lasting recruitment maneuvers (RMs) may improve oxygenation and enable reduction of subsequent conventional mechanical ventilation (CMV) pressures. We determined the effect of adding HFO-TGI sessions to lung-protective CMV on physiological variables in patients with early/severe ARDS. We conducted a prospective, randomized, unblinded clinical trial, subdivided into a first single-centre period and a second two-centre period. We enrolled 125 (first period, n = 54) patients with arterial oxygen tension (PaO2)/inspiratory oxygen fraction (FiO2) of 12 consecutive hours at an end-expiratory pressure of ≥ 8cmH2O . Patients were randomly assigned to an HFO-TGI group (receiving HFO-TGI sessions with RMs, interspersed with lung-protective CMV; n = 61) or CMV group (receiving lung-protective CMV and RMs; n = 64). Pre-enrolment ventilation duration was variable. During days 1-10 post-randomization, PaO2/FiO2, oxygenation index, plateau pressure and respiratory compliance were improved in the HFO-TGI group versus the CMV group (p 0,09 for Mean Arterial Pressure and P=0,08 for Central Venus Pressure).Στο σύνδρομο οξείας αναπνευστικής δυσπραγίας (Acute Respiratory Distress Syndrome-ARDS), οι συνεδρίες επιστράτευσης με μηχανικό αερισμό υψηλής συχνότητας (High Frequency Oscillation-HFO) και ενδοτραχειακής εμφύσησης αεριών (Tracheal Gas Insuflation-TGI) με σύντομους, «κλασσικούς» χειρισμούς επιστράτευσης (εφαρμογή συνεχούς θετικής πίεσης αεραγωγών 45cmH2O για 45 δευτερόλεπτα-Recruitment Maneuvers-RMs), μπορεί να βελτιώσει την οξυγόνωση και να επιτρέψει την ελάττωση των πιέσεων του συμβατικού μηχανικού αερισμού (Conventional Mechanical Ventilation-CMV). Καταγράφηκε η επίπτωση της προσθήκης συνεδριών HFO-TGI στο μοντέλο του προστατευτικού CMV πάνω στις φυσιολογικές μεταβλητές των ασθενών με πρώιμο/βαρύ ARDS. Πραγματοποιήσαμε μία προοπτική, τυχαιοποιημένη, μη τυφλή κλινική μελέτη, η οποία χωρίστηκε χρονικά σε μία πρώτη, μονοκεντρική, περίοδο και σε μία δεύτερη, δικεντρική, περίοδο. Συμπεριελήφθησαν 125 συνολικά ασθενείς (54 ασθενείς από την πρώτη περίοδο), με τιμή του λόγου της μερικής τάσης του οξυγόνου του αρτηριακού αίματος (PaO2) προς την κλασματική συγκέντρωση του οξυγόνου στον εισπνεόμενο αέρα (FiO2) μικρότερη των 150mmHg για περισσότερες από 12 συνεχείς ώρες και με τιμή θετικής τελοεκπνευστικής πίεσης (Positive End-Expiratory Pressure-PEEP) στον CMV μεγαλύτερη ή ίση των 8cmH2O. Οι ασθενείς τυχαιοποιήθηκαν είτε στην ομάδα του HFO-TGI (λαμβάνοντας συνεδρίες με συνδυασμό HFO-TGI με χειρισμούς επιστράτευσης (RMs) και εναλλαγή με προστατευτικό μοντέλο CMV, σύνολο=61 ασθενείς) είτε στην ομάδα του CMV (λαμβάνοντας συνδυασμό προστατευτικού μοντέλου CMV με χειρισμούς επιστράτευσης, σύνολο=64 ασθενείς). Η χρονική διάρκεια του CMV πριν την τυχαιοποίηση, ήταν μεταβλητή ανάμεσα στους ασθενείς. Κατά την διάρκεια των ημερών 1-10 μετά την τυχαιοποίηση, ο λόγος PaO2/FiO2, ο δείκτης οξυγόνωσης, η τελοεισπνευστική πίεση ισορροπίας και η ενδοτικότητα του αναπνευστικού συστήματος, ήταν βελτιωμένοι στους ασθενείς της ομάδας του HFO-TGI σε σχέση με την ομάδα του CMV (P0,09 για την μέση αρτηριακή πίεση (MAP) και P=0,08 για την κεντρική φλεβική πίεση (CVP)]

“Low-” versus “high”-frequency oscillation and right ventricular function in ARDS. A randomized crossover study

Abstract Background Recent, large trials of high-frequency oscillation (HFO) versus conventional ventilation (CV) in acute respiratory distress syndrome (ARDS) reported negative results. This could be explained by an HFO-induced right ventricular (RV) dysfunction/failure due to high intrathoracic pressures and hypercapnia. We hypothesized that HFO strategies aimed at averting/attenuating hypercapnia, such as “low-frequency” (i.e., 4 Hz) HFO and 4-Hz HFO with tracheal-gas insufflation (HFO-TGI), may result in an improved RV function relative to “high-frequency” (i.e., 7 Hz) HFO (which may promote hypercapnia) and similar RV function relative to lung protective CV. Methods We studied 17 patients with moderate-to-severe ARDS [PaO2-to-inspiratory O2 fraction ratio (PaO2/FiO2) < 150]. RV function was assessed by transesophageal echocardiography (TEE). Patients received 60 min of CV for TEE-guided, positive end-expiratory pressure (PEEP) “optimization” and subsequent stabilization; 60 min of 4-Hz HFO for “study mean airway pressure (mPaw)” titration to peripheral oxygen saturation ≥ 95%, without worsening RV function as assessed by TEE; 60 min of each tested HFO strategy in random order; and another 60 min of CV using the pre-HFO, TEE-guided PEEP setting. Study measurements (i.e., gas exchange, hemodynamics, and TEE data) were obtained over the last 10 min of pre-HFO CV, of each one of the three tested HFO strategies, and of post-HFO CV. Results The mean “study HFO mPaw” was 8–10 cmH2O higher relative to pre-HFO CV. Seven-Hz HFO versus 4-Hz HFO and 4-Hz HFO-TGI resulted in higher mean ± SD right-to-left ventricular end-diastolic area ratio (RVEDA/LVEDA) (0.64 ± 0.15 versus 0.56 ± 0.14 and 0.52 ± 0.10, respectively, both p < 0.05). Higher diastolic/systolic eccentricity indexes (1.33 ± 0.19/1.42 ± 0.17 versus 1.21 ± 0.10/1.26 ± 0.10 and 1.17 ± 0.11/1.17 ± 0.13, respectively, all p < 0.05). Seven-Hz HFO resulted in 18–28% higher PaCO2 relative to all other ventilatory strategies (all p < 0.05). Four-Hz HFO-TGI versus pre-HFO CV resulted in 15% lower RVEDA/LVEDA, and 7%/10% lower diastolic/systolic eccentricity indexes (all p < 0.05). Mean PaO2/FiO2 improved by 77–80% during HFO strategies versus CV (all p < 0.05). Mean cardiac index varied by ≤ 10% among strategies. Percent changes in PaCO2 among strategies were predictive of concurrent percent changes in measures of RV function (R 2 = 0.21–0.43). Conclusions In moderate-to-severe ARDS, “short-term” 4-Hz HFO strategies resulted in better RV function versus 7-Hz HFO, partly attributable to improved PaCO2 control, and similar or improved RV function versus CV. Trial registration This study was registered 40 days prior to the enrollment of the first patient at ClinicalTrials.gov, ID no. NCT02027129, Principal Investigator Spyros D. Mentzelopoulos, date of registration January 3, 2014

Scanographic comparison of high frequency oscillation with versus without tracheal gas insufflation in acute respiratory distress syndrome

In acute respiratory distress syndrome (ARDS), combined high frequency oscillation (HFO) and tracheal gas insufflation (TGI) improves oxygenation versus standard HFO, likely through TGI-induced lung recruitment. Experimental data suggest that steady flows such as TGI favor the filling of the lower (i.e., subcarinal) lung. We used whole-lung computerized tomography (CT) to determine whether HFO-TGI versus HFO improves the recruitment of the lower lung, and especially of its dependent region, where loss of aeration is maximized in ARDS. We enrolled 15 patients who had ARDS for 96 h or less, and pulmonary infiltrates in at least three chest X-ray quadrants. Patients were subjected to whole-lung CT after lung-protective conventional mechanical ventilation (CMV) and after 45 min of HFO and 45 min of HFO-TGI. HFO/HFO-TGI were employed in random order. CT scans were obtained at a continuous positive airways pressure equal to the mean tracheal pressure (P (tr)) of CMV. During HFO/HFO-TGI, mean airway pressure was titrated to the CMV P (tr) level. Gas exchange and intra-arterial pressure/heart rate were determined for each ventilatory technique. Regarding total lung parenchyma, HFO-TGI versus HFO and CMV resulted in a lower percentage of nonaerated lung tissue (mean +/- A SD, 51.4 +/- A 5.1% vs. 60.0 +/- A 2.5%, and 62.1 +/- A 9.0%, respectively; P a parts per thousand currency sign 0.04); this was due to HFO-TGI-induced recruitment of nonaerated tissue in the dependent and nondependent lower lung. HFO-TGI increased normally aerated tissue versus CMV (P = 0.04) and poorly aerated tissue versus HFO and CMV (P a parts per thousand currency sign 0.04), and improved oxygenation versus HFO and CMV (P a parts per thousand currency sign 0.04). HFO-TGI improves oxygenation versus HFO and CMV through the recruitment of previously nonaerated lower lung units

Does Route of Full Feeding Affect Outcome among Ventilated Critically Ill COVID-19 Patients: A Prospective Observational Study

The outbreak of the new coronavirus strain SARS-CoV-2 (COVID-19) highlighted the need for appropriate feeding practices among critically ill patients admitted to the intensive care unit (ICU). This study aimed to describe feeding practices of intubated COVID-19 patients during their second week of hospitalization in the First Department of Critical Care Medicine, Evaggelismos General Hospital, and evaluate potential associations with all cause 30-day mortality, length of hospital stay, and duration of mechanical ventilation. We enrolled adult intubated COVID-19 patients admitted to the ICU between September 2020 and July 2021 and prospectively monitored until their hospital discharge. Of the 162 patients analyzed (52.8% men, 51.6% overweight/obese, mean age 63.2 &plusmn; 11.9 years), 27.2% of patients used parenteral nutrition, while the rest were fed enterally. By 30 days, 34.2% of the patients in the parenteral group had died compared to 32.7% of the patients in the enteral group (relative risk (RR) for the group receiving enteral nutrition = 0.97, 95% confidence interval = 0.88&ndash;1.06, p = 0.120). Those in the enteral group demonstrated a lower duration of hospital stay (RR = 0.91, 95% CI = 0.85-0.97, p = 0.036) as well as mechanical ventilation support (RR = 0.94, 95% CI = 0.89&ndash;0.99, p = 0.043). Enteral feeding during second week of ICU hospitalization may be associated with a shorter duration of hospitalization and stay in mechanical ventilation support among critically ill intubated patients with COVID-19