Noninvasive Respiratory Support Techniques Research Articles

Focus on the Role of Non-Invasive Respiratory Support (NRS) during Palliative Care in Patients with Life-Limiting Respiratory Disease.

The management of patients with life-threatening respiratory disease in the ICU and at home has become increasingly of interest over the past decades. Growing knowledge supports the use of NRS, aimed at improving patient comfort and improving quality of life. However, its role during palliative care is not well defined, and evidence of support remains limited. The aim of this narrative review is to examine the recent evidence relating to the use of non-invasive respiratory support at the end of life, in order to clarify who benefits and when. The literature research was conducted on PubMed, using MeSH words. A review of the relevant literature showed that non-invasive respiratory support techniques for patients with life-limiting respiratory disease vary (from high-flow oxygen therapy to conventional oxygen therapy, from CPAP to NPPV) and each has precise indications. To date, from the hospital to the home setting, the monitoring and application of these respiratory support techniques have varied widely. In conclusion, the choice of respiratory support in this category of patients should be based on the technique that will optimize the comfort of the patient and improve the quality of their life. On the other hand, regarding monitoring, both telemedicine and ultrasound diagnostics help to satisfy the patient's wish to spend the last period of his life in the home environment, to avoid inappropriately aggressive diagnostic interventions, and to reduce the high costs of hospitalized procedures in this category of patients.

SIMEU position paper on non-invasive respiratory support in COVID-19 pneumonia.

The rapid worldwide spread of the Coronavirus disease (COVID-19) crisis has put health systems under pressure to a level never experienced before, putting intensive care units in a position to fail to meet an exponentially growing demand. The main clinical feature of the disease is a progressive arterial hypoxemia which rapidly leads to ARDS which makes the use of intensive care and mechanical ventilation almost inevitable. The difficulty of health systems to guarantee a corresponding supply of resources in intensive care, together with the uncertain results reported in the literature with respect to patients who undergo early conventional ventilation, make the search for alternative methods of oxygenation and ventilation and potentially preventive of the need for tracheal intubation, such as non-invasive respiratory support techniques particularly valuable. In this context, the Emergency Department, located between the area outside the hospital and hospital ward and ICU, assumes the role of a crucial junction, due to the possibility of applying these techniques at a sufficiently early stage and being able to rapidly evaluate their effectiveness. This position paper describes the indications for the use of non-invasive respiratory support techniques in respiratory failure secondary to COVID-19-related pneumonia, formulated by the Non-invasive Ventilation Faculty of the Italian Society of Emergency Medicine (SIMEU) on the base of what is available in the literature and on the authors' direct experience. Rationale, literature, tips & tricks, resources, risks and expected results, and patient interaction will be discussed for each one of the escalating non-invasive respiratory techniques: standard oxygen, HFNCO, CPAP, NIPPV, and awake self-repositioning. The final chapter describes our suggested approach to the failing patient.

Non-invasive respiratory support techniques for COVID-19 pneumonia outside the ICU: still far from the truth?

article: Non-invasive respiratory support techniques for COVID-19 pneumonia outside the ICU: still far from the truth? - Italian Journal of Emergency Medicine 2021 December;10(3):118-22 - Minerva Medica - Journals

The impact of non-invasive respiratory support techniques on the lethal outcome frequency in adult with severe respiratory failure caused by the new coronavirus infection

The objective: to evaluate the effect of high-flow oxygen and non-invasive ventilation on the mortality rate in adults with severe respiratory failure caused by the new coronavirus infection in the intensive care unit (ICU).Subjects and methods. A one-center retrospective study was conducted. Electronic medical files of patients treated in the ICU from April 1 to May 25, 2020, were analyzed. Totally, 101 medical files were selected, further, they were divided into two groups. Group 1 (n = 49) included patients who received oxygen insufflation, and should it fail, they received traditional artificial ventilation. No non-invasive respiratory therapy was used in this group. Group 2 (n = 52) included patients who received high-flow oxygen therapy and non-invasive ventilation. The mortality rate in the groups made a primary endpoint for assessing the impact of high-flow oxygen therapy and non-invasive ventilation. The following parameters were also analyzed: drug therapy, the number of patients in whom non-invasive techniques were used taking into account the frequency of cases when these techniques failed, and the number of patients in whom artificial ventilation was initiated.Results. In Group 2, non-invasive methods of respiratory therapy were used in 31 (60%) cases. High-flow oxygen therapy was used in 19 (36%) of them; in 13 cases this method allowed weaning them from the high flow. Non-invasive ventilation was used in 18 cases, in 12 patients it was used due to progressing severe respiratory failure during humidified oxygen insufflation, in 6 patients – after the failed high-flow oxygen therapy. In Group 1, 25 (51%) patients were intubated and transferred to artificial ventilation, in Group 2, 10 (19.2%) underwent the same. The lethal outcome was registered in 23 (47%) cases in Group 1, and in 10 (19.2%) in Group 2 (p = 0.004). Analysis of drug therapy in the groups revealed the difference in the prescription of pathogenetic therapy. Logistic regression demonstrated the effectiveness of the combination of tocilizumab + a glucocorticoid in reducing the frequency of lethal cases (p = 0.001).Conclusion. The use of non-invasive respiratory support in adults with severe respiratory failure caused by the new coronavirus infection combined with therapy by tocilizumab + a glucocorticoid can reduce the incidence of lethal cases.

Comparison of four different non-invasive respiratory support techniques as primary respiratory support in preterm infants.

The use of non-invasive ventilation methods in neonatal intensive care units has been increasing in recent years. Non-invasive ventilation techniques are lung preserving methods and they reduce the risk of volutrauma, barotrauma, and atelectotrauma. The effect of heated humidified high-flow nasal cannula (HHHFNC), continuous positive airway pressure (CPAP), nasal intermittent positive-pressure ventilation (NIPPV), and nasal high-frequency oscillation ventilation (NHFOV) were compared in preterm infants with respiratory distress. Between December 2015 and February 2017, a total of 76 preterm infants (gestational age < 32 weeks) with respiratory distress were enrolled in this study. Of the patients, 20 received HHHFNC, while 20 received nasal CPAP (NCPAP), 19 received NIPPV, and 17 received NHFOV for respiratory support. The primary outcome was intubation requirement during non-invasive respiratory support. The secondary outcome included duration of non-invasive ventilation, air leak syndrome, abdominal distension, intraventricular hemorrhage, necrotizing enterocolitis (NEC), nasal injury, increased secretions, agitation, and mortality rate. The intubation ratio was higher in the NCPAP (40%) and NHFOV (29.4%) groups when compared with the NIPPV (10.5%) and HHHFNC (11.8%) groups. More nasal injury had developed in the NIPPV (78.9%) and NHFOV (82.4%) groups when compared with the NCPAP (40%) and HHHFNC (35%) groups. Moreover, the viscous secretion that blocked the cannulas was higher in NIPPV (78.9%) and NHFOV (76.5%) groups than NCPAP (25%) and HHHFNC (40%) groups. There were no significant differences in the duration of non-invasive ventilation methods, abdominal distension, NEC, air leak syndrome or mortality in the 4 groups. The NIPPV and HHHFNC methods can be useful as a primary mode of respiratory support for respiratory distress. However, doctors need to be careful with regard to the complications that may develop.

Non-Invasive Respiratory Support During Covid-19 Pandemic

Acute respiratory failure frequently occurs in severe COVID-19 and requires ventilator support. However, during the first wave of the pandemic, conventional resources for critically ill patients were insufficient in many centers. Therefore, an alternative strategy based on the use of non-invasive respiratory support (NIRS), and especially continuous positive airway pressure (CPAP), have been massively employed, either as a definitive therapy or as a bridge for orotracheal intubation. The results of this strategy have been excellent. If patients are carefully selected and monitored and NIRS is managed by an expert team in an appropriate environment, the vast majority of patients survive, avoiding intubation in most cases, and even decreasing the possibility of a self-inflicted lung injury (SILI). Moreover, there is evidence that with these techniques the risk of aerosolization is low. Nowadays, CPAP is considered the best option for most patients, with BiPAP being especially recommended in those with previous thoracic diseases or chronic hypercapnia. We conclude that NIRS techniques can be used in the initial care of most patients with severe respiratory failure from COVID-19 pneumonia and/or thromboembolism. To achieve the best results, intermediate care units, where specialized respiratory support can be provided, are the most appropriate framework.

Clinical experience of high-flow nasal cannula oxygen therapy in severe COVID-19 patients

Acute respiratory failure due to acute hypoxemia is the major manifestation in severe coronavirus disease 2019 (COVID-19). Rational and effective respiratory support is crucial in the management of COVID-19 patients. High-flow nasal cannula (HFNC) has been utilized widely due to its superiority over other non-invasive respiratory support techniques. To avoid HFNC failure and intubation delay, the key issues are proper patients, timely application and improving compliance. It should be noted that elder patients are vulnerable for failed HFNC. We applied HFNC for oxygen therapy in severe and critical ill COVID-19 patients and summarized the following experiences. Firstly, to select the proper size of nasal catheter, to locate it at suitable place, and to confirm the nose and the upper respiratory airway unobstructed. Secondly, an initial ow of 60 L/min and 37℃ should be given immediately for patients with obvious respiratory distress or weak cough ability; otherwise, low-level support should be given first and the level gradually increased. Thirdly, to avoid hypoxia or hypoxemia, the treatment goal of HFNC should be maintained the oxygen saturation (SpO2) above 95% for patients without chronic pulmonary disease. Finally, patients should wear a surgical mask during HFNC treatment to reduce the risk of virus transmission through droplets or aerosols.

Noninvasive respiratory support in the hypoxaemic peri-operative/periprocedural patient: A joint ESA/ESICM guideline.

: Hypoxaemia is a potential life-threatening yet common complication in the peri-operative and periprocedural patient (e.g. during an invasive procedure with risk of deterioration of gas exchange, such as bronchoscopy). The European Society of Anaesthesiology (ESA) and the European Society of Intensive Care Medicine (ESICM) have developed guidelines for the use of noninvasive respiratory support techniques in the hypoxaemic patient in the peri-operative and periprocedural period. The panel outlined five clinical questions regarding treatment with noninvasive respiratory support techniques [conventional oxygen therapy (COT), high flow nasal cannula (HFNC), noninvasive positive pressure ventilation (NIPPV) and continuous positive airway pressure (CPAP)] for hypoxaemic patients with acute peri-operative/periprocedural respiratory failure. The goal was to assess the available literature on the various noninvasive respiratory support techniques, specifically studies that included adult participants with hypoxaemia in the peri-operative/periprocedural period. The literature search strategy was developed by a Cochrane Anaesthesia and Intensive Care trial search specialist in close collaboration with the panel members and the ESA group methodologist. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to assess the level of evidence and to grade recommendations. The final process was then validated by both ESA and ESICM scientific committees. Among 19 recommendations, the two grade 1B recommendations state that in the peri-operative/periprocedural hypoxaemic patient, the use of either NIPPV or CPAP (based on local expertise) is preferred to COT for improvement of oxygenation; and that the panel suggests using NIPPV or CPAP immediately postextubation for hypoxaemic patients at risk of developing acute respiratory failure after abdominal surgery.

Noninvasive respiratory support in the hypoxaemic peri-operative/periprocedural patient: a joint ESA/ESICM guideline.

Hypoxaemia is a potential life-threatening yet common complication in the peri-operative and periprocedural patient (e.g. during an invasive procedure at risk of deterioration of gas exchange, such as bronchoscopy). The European Society of Anaesthesiology (ESA) and the European Society of Intensive Care Medicine (ESICM) developed guidelines for the use of noninvasive respiratory support techniques in the hypoxaemic patient in the peri-operative and periprocedural period. The panel outlined five clinical questions regarding treatment with noninvasive respiratory support techniques [conventional oxygen therapy (COT), high flow nasal cannula, noninvasive positive pressure ventilation (NIPPV) and continuous positive airway pressure (CPAP)] for hypoxaemic patients with acute peri-operative/periprocedural respiratory failure. The goal was to assess the available literature on the various noninvasive respiratory support techniques, specifically studies that included adult participants with hypoxaemia in the peri-operative/periprocedural period. The literature search strategy was developed by a Cochrane Anaesthesia and Intensive Care trial search specialist in close collaboration with the panel members and the ESA group methodologist. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to assess the level of evidence and to grade recommendations. The final process was then validated by both ESA and ESICM scientific committees. Among 19 recommendations, the two grade 1B recommendations state that: in the peri-operative/periprocedural hypoxaemic patient, the use of either NIPPV or CPAP (based on local expertise) is preferred to COT for improvement of oxygenation; and that the panel suggests using NIPPV or CPAP immediately post-extubation for hypoxaemic patients at risk of developing acute respiratory failure after abdominal surgery. Electronic supplementary materialThe online version of this article (10.1007/s00134-020-05948-0) contains supplementary material, which is available to authorized users.

Influence of Noninvasive Respiratory Support Techniques on Gas Exchange in Cardiac Surgical Patients Suffering from Post-Operative Respiratory Failure

Respiratory failure (RF) after tracheal extubation occurs in 5–25% of cardiac surgical patients. Various noninvasive respiratory support techniques are available for RF treatment.The purpose of the study is a comparative assessment of the effect on gas exchange of oxygen inhalation through a mask with noninvasive airway positive pressure mask ventilation, and high-flow lung ventilation during post-extubation respiratory failure in cardiac surgical patients.Materials and methods. 52 cardiac surgical patients with post-extubation respiratory failure (mean age 61 (55–67) years) were included in the study. Respiratory failure critera were as follows: PaO2/FiO2 _ 300 mm Hg or SpO2 _ 88% during room air breathing. Exclusion criteria included presentation of pleural effusion in patients, pneumothorax, diaphragm paresis. Every patient was subjected consecutively to arterial blood gases test during room air breathing, low-flow oxygen therapy using a mask with a pre-volume bag, high-flow ventilation (HFNC), and noninvasive positive pressure mask ventilation (NIPPV). Each method was applied during 1 hour prior to the test. Respiratory rate (RR) and capillary blood saturation (SpO2) were monitored throughout the whole study.Results. PaO2/FiO2 during low-flow oxygen therapy was equal to 171 (137–243) mm Hg. At the background of HFNC, this index increased to 235 (183–305) mm Hg (P=0.00004), and upon transfer to NIPPV — to 228 (180–288) mm Hg (P=0.000028). SpO2 during HFNC and NIPPV increased from 95 (93–98)% to 98 (96–99)% (P=0.000006) and 97 (95–98)%, respectively (P=0.000006 and P=0.000069). PaCO2 was higher during oxygen mask breathing compared to air breathing: 41 (37–44) mm Hg and 38 (34–42) mm Hg, correspondingly, P=0.0017. Upon transfer to HFNC, PaCO2 lowered on average by 10% (37 (33–39) mm Hg, P=0.0000001), to NIPPV — by 7% (38 (36–42) mm Hg, P=0,0015). Differences were also significant when compred RR during oxygen mask breathing (20 (16–24) respirations/minute) vs. HFNC (16 (12–20) respirations/minute, P=0.0) and vs. NIPPV (18 (16–20) respirations/minute, P=0.018). Comparison of HFNC vs. NIPPV revealed reliable difference in RR (16 (12–20) respirations/minute against 18 (16-20) respirations/minute, P=0.016), PaCO2 (37 (33–39) mm Hg against 38 (36–42) mm Hg, P=0.0034), and SpO2 (98 (96–99)% against 97 (95–98)%, P=0.022).Conclusion. HFNC and NIPPV exert a similar positive effect on the oxygenating function of lungs and gas exchange in cardiac surgical patients with post-extubation respiratory failure. Compared to NIPPV, high-flow ventilation renders most significant positive effect on elimination of CO2, RR and SpO2, and is better tolerated by patients.

Heated Humidified High Flow Nasal Cannula (HHHFNC) is not an effective method for initial treatment of Respiratory Distress Syndrome (RDS) versus nasal intermittent mandatory ventilation (NIMV) and nasal continuous positive airway pressure (NCPAP).

Background:Noninvasive respiratory support techniques are widely used to treat respiratory distress syndrome (RDS) in preterm infants, and the effectiveness of these methods should be compared. In the current study, nasal continuous positive airway pressure (NCPAP), nasal intermittent mandatory ventilation (NIMV), and heated humidified high-flow nasal cannula (HHHFNC) were compared.Materials and Methods:In the current bicenter clinical trial, 109 preterm infants with RDS not treated with surfactant were randomly assigned to three groups: NCPAP, NIMV, and HHHFNC. The initial outcomes including the failure of treatment within the first initial 72 h, and the duration of RDS treatment, and the secondary outcomes including the need for intubation, the need for surfactants, the duration of oxygen dependency, the incidence of pneumothorax, the patent ductus arteriosus, intraventricular hemorrhage, length of stay, and mortality were compared among the groups.Results:The frequency of HHHFNC treatment failure (54.3%) was significantly higher compared with those of NIMV (21.6%) (P < 0.001, hazard ratio [HR] = 9.12, 95% confidence interval [CI] = 2.59 – 32.07) and NCPAP (35.1%) (P = 0.004, HR = 21.25, 95% CI = 2.51–180.08). The median duration of RDS treatment was longer (40 h) in the HHHFNC group, although it was not significantly different from those of NIMV (31.16 h) and NCPAP (38.91 h).Conclusion:Based on the high prevalence of failure of HHHFNC treatment than the other two methods (NCPAP and NIMV), HHHFNC is not recommended as the initial treatment of RDS.

Experimental and Numerical Modeling of Aerosol Delivery for Preterm Infants

Respiratory distress syndrome (RDS) represents one of the major causes of mortality among preterm infants, and the best approach to treat it is an open research issue. The use of perfluorocarbons (PFC) along with non-invasive respiratory support techniques has proven the usefulness of PFC as a complementary substance to achieve a more homogeneous surfactant distribution. The aim of this work was to study the inhaled particles generated by means of an intracorporeal inhalation catheter, evaluating the size and mass distribution of different PFC aerosols. In this article, we discuss different experiments with the PFC perfluorodecalin (PFD) and FC75 with a driving pressure of 4–5 bar, evaluating properties such as the aerodynamic diameter (Da), since its value is directly linked to particle deposition in the lung. Furthermore, we develop a numerical model with computational fluid dynamics (CFD) techniques. The computational results showed an accurate prediction of the airflow axial velocity at different downstream positions when compared with the data gathered from the real experiments. The numerical validation of the cumulative mass distribution for PFD particles also confirmed a closer match with the experimental data measured at the optimal distance of 60 mm from the catheter tip. In the case of FC75, the cumulative mass fraction for particles above 10 µm was considerable higher with a driving pressure of 5 bar. These numerical models could be a helpful tool to assist parametric studies of new non-invasive devices for the treatment of RDS in preterm infants.

Noninvasive Strategies for Management of Respiratory Problems in Neonates

Multiple techniques have been developed to provide noninvasive strategies for respiratory support of the newborn that provide positive airway pressure continuously, with or without ventilation cycles, in nonintubated infants. The core physiologic variable is positive airway pressure used clinically as nasal continuous positive airway pressure (CPAP). CPAP can be augmented with intermittent positive pressure breaths that are, or are not, synchronized to the breathing of the infant. Pressures delivered by high-flow nasal cannula are less predictable than those delivered by a CPAP device. A renewed interest in testing and innovating to improve noninvasive respiratory support techniques has resulted from efforts to avoid intubation, mechanical ventilation, and ultimately bronchopulmonary dysplasia. These noninvasive techniques now are used to stabilize respiratory status after birth, to manage respiratory distress syndrome, and to facilitate extubation of infants. Large trials, in aggregate, demonstrate a modest benefit from the use of CPAP soon after birth, relative to intubation, surfactant treatment, and ventilation. Small trials yield conflicting results for the relative benefits of different noninvasive techniques for the clinical management of respiratory distress syndrome and for attempts at extubation. Success with noninvasive ventilation for the management of preterm infants depends greatly on the skills and commitment of the personnel caring for the infant.

Ventilatory management and bronchopulmonary dysplasia in preterm infants

Improvements in antenatal and neonatal care have resulted in increased survival of very preterm infants. However, the incidence of bronchopulmonary dysplasia (BPD) has not changed, probably as a consequence of a demographic shift. The underlying pathophysiology of BPD appears to differ for the current population of preterm infants compared to that described by Northway et al., and management strategies should be targeted to limit ventilator-induced lung injury. Non-invasive respiratory support techniques are currently under evaluation, but results of the trials have thus far failed to show a reduction in BPD. This review will focus upon various ventilation modalities for preventing and managing bronchopulmonary dysplasia.

Extending the preoxygenation period from 4 to 8 mins in critically ill patients undergoing emergency intubation*

To determine the effectiveness of increasing the preoxygenation period with 100% oxygen in the critically ill patient from 4 to 8 mins in preparation for emergency tracheal intubation. Nonrandomized, controlled trial. Large, level one trauma center, tertiary care intensive care unit. Critically ill patients failing noninvasive respiratory support techniques who required tracheal intubation followed by mechanical ventilation. A baseline arterial blood gas was obtained on noninvasive passive therapy and at 4, 6, and 8 mins of active preoxygenation efforts with 100% oxygen therapy with a noncollapsing resuscitator bag and mask. Best effort to achieve a tight fitting mask seal was pursued coupled with other mask ventilation maneuvers to optimize noninvasive oxygenation and ventilation. Thirty-four patients consecutively intubated by the author during the 7-month study period were studied. The baseline PaO2 (mean +/- SD) with concurrent noninvasive support was 61.9 +/- 14.6 mm Hg (range: 44-109 mm Hg) and increased a mean of 22 mm Hg to 83.8 +/- 51.5 mm Hg after 4 mins of preoxygenation (p < 0.01). Continued preoxygenation efforts (6 mins) increased the PaO2 to 88.2 mm Hg +/- 48.5 and after 8 mins to 92.7 mm Hg +/- 55.2. At the 8-min mark, 5 of 34 patients achieved > 10% increase in their PaO2 and only two patients increased their 4-min PaO2 by > or = 50 mm Hg after the additional 4 mins of preoxygenation. One quarter of the patients experienced a reduction in their PaO2 from the 4 to the 8-min time period. Nearly, 50% of the patients met the criteria for desaturation during the intubation procedure. Extending the preoxygenation period from the customary 4 mins to either 6 or 8 min seems to be marginally effective in the majority of patient suffering from cardiopulmonary deterioration and such an extension may jeopardize oxygenation efforts in some patients.

Preoxygenation in critically ill patients requiring emergency tracheal intubation*

To determine the effectiveness of preoxygenation with 100% oxygen in the critically ill patient in preparation for emergency tracheal intubation. Nonrandomized, controlled trial. Large, level 1 trauma center, tertiary care intensive care unit. Critically ill patients failing noninvasive respiratory support techniques who require tracheal intubation followed by mechanical ventilation. A baseline arterial blood gas was obtained on noninvasive therapy and 4 mins post-100% oxygen therapy with a bag-mask assembly. Best effort to achieve a tight-fitting mask seal was pursued coupled with other mask ventilation maneuvers to optimize noninvasive oxygenation and ventilation. A total of 42 patients consecutively intubated during the 15-month study period were studied. The baseline Pao2 (mean +/- sd) with concurrent noninvasive support was 67 +/- 19.6 mm Hg (range, 43-88 mm Hg) and increased a mean of 37 mm Hg to 103.8 +/- 63.2 mm Hg after 4 mins of preoxygenation with 100% oxygen. A total of 36% of patients had minimal changes (+/-5%) in their baseline Pao2, and only 19% increased their baseline Pao2 by at least 50 mm Hg after preoxygenation maneuvers. The critically ill patient has little reserve to tolerate interruption of oxygen delivery and, thus, is at risk for hypoxemia during emergency airway management. Preoxygenation efforts as described in this clinical trial appear to be marginally effective in regard to providing a reasonable safeguard against hypoxemia during laryngoscopy and endotracheal intubation.