[Weaning from invasive mechanical ventilation]

Weaning from invasive mechanical ventilation is challenging for the ICU team in terms of shortening time of ventilation via endotracheal tube in order to improve the patient's prognosis by early extubation. Thereby prolonged mechanical ventilation (> 14 days), which is associated with risk of tracheotomy and prolonged weaning, shall be avoided. This article will give an overview about weaning categories, causes for weaning failure and strategies to overcome this problem. In the last part we will cover concepts in the process of prolonged weaning including discharge management with invasive mechanical ventilation.

Nursing evaluation during treatment with helmet continuous positive airway pressure in patients with respiratory failure due to COVID-19 pneumonia: A case series

Background

During COVID-19 outbreak, with the increasing number of patients presenting with acute respiratory failure, a large use of non invasive positive pressure ventilation was done in the emergency departments and medical wards despite the lack of recommendations.

Objectives

This study describes the clinical characteristics of patients presenting to the hospital with acute respiratory failure due to COVID-19 related pneumonia undergoing treatment with helmet continuous positive airway pressure (CPAP) with a strict nursing evaluation and monitoring.

Methods

A case series study enrolling adult patients admitted to an emergency department of an Italian hospital with acute respiratory failure due to COVID-19 pneumonia from March 18th to April 18th, 2020, was conducted. Only patients who strictly followed a local CPAP protocol were enrolled.

Results

A total of 52 patients were included in this study. Thirty-eight patients (73%) were judged eligible for endotracheal intubation (ETI). Eighteen (34.6%) were intubated. Sixteen (30.8%) patients died: seven (38.9%) and nine (26.5%) in the eligible-for-ETI and non eligible-for-ETI group, respectively. The median hospital length of stay was different in the ETI and non-ETI group: 26 days (interquartile range [IQR]: 16–37) vs 15 days [IQR 9–17] (p = 0.005). The median invasive mechanical ventilation time was 11 days [IQR 7–21] with an ICU length of stay of 14.5 days [IQR 10–28]. During the CPAP trial, among patients eligible for ETI variations over time for positive end-expiratory pressure (p = 0.003) and respiratory rate (p = 0.059) were found between intubated and non-intubated patients.

Conclusions

A short closed monitored CPAP trial could be considered for acute respiratory failure due to COVID-19 pneumonia before considering ETI. A progressive positive end-expiratory pressure titration should target reduction in a patient’s respiratory rate. More studies are needed to evaluate the efficacy and predictors of failure of CPAP and non-invasive positive pressure ventilation in patients with acute respiratory failure due to COVID-19 pneumonia.

Continuous noninvasive ventilatory support outcomes for patients with neuromuscular disease: a multicenter data collaboration

BACKGROUND

Typically, patients with progressive neuromuscular disorders (NMDs) develop acute respiratory failure (ARF), are intubated, and when failing spontaneous breathing trials (SBTs) undergo a tracheotomy and receive tracheostomy mechanical ventilation (TMV). However, increasing numbers of patients use nasal noninvasive ventilation (NIV), initially for sleep and this is extended to continuous dependence (CNVS). This can be used as a strategy to assist in successful extubation . We retrospectively reviewed 19 centers offering CNVS and mechanical insufflation-exsufflation (MI-E) as an alternative to TMV.

METHODS

Centers with publications or presentations concerning CNVS outcomes data were pooled for amyotrophic lateral sclerosis (ALS), Duchenne muscular dystrophy (DMD), and spinal muscular atrophy type 1 (SMA1). Progression to CNVS dependence without hospitalization, duration of dependence, and extubations and decannulations to CNVS were recorded. Prolongation of life was defined by duration of CNVS dependence without ventilator free breathing ability (VFBA).

RESULTS

There were 1623 part time (<23 h/day) NVS users with ALS, DMD, and SMA1 from 19 centers in 16 countries of whom 761 (47%) were CNVS dependent for 2218 patient-years. This included: 335 ALS patients for a mean 1.2 ± 1.0 (range to 8) years each; 385 DMD patients for 5.4 ± 1.6 (range to 29) years; and 41 SMA1 patients for 5.9 ± 1.8 (range to 20) years. Thirty-five DMD and ALS TMV users were decannulated to CNVS and MI-E. At data collection 494 (65%) patients were CNVS dependent but 110 (74 of whom with bulbar ALS), had undergone tracheotomies.

CONCLUSIONS

ALS, DMD, and SMA1 patients can become CNVS dependent without requiring hospitalization but CNVS cannot be used indefinitely for many patients with advanced upper motor neuron diseases.

Long-term survival of mechanically ventilated patients with severe COVID-19: an observational cohort study

Background

Information is lacking regarding long-term survival and predictive factors for mortality in patients with acute hypoxemic respiratory failure due to coronavirus disease 2019 (COVID-19) and undergoing invasive mechanical ventilation. We aimed to estimate 180-day mortality of patients with COVID-19 requiring invasive ventilation, and to develop a predictive model for long-term mortality.

Methods

Retrospective, multicentre, national cohort study between March 8 and April 30, 2020 in 16 intensive care units (ICU) in Spain. Participants were consecutive adults who received invasive mechanical ventilation for COVID-19. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection detected in positive testing of a nasopharyngeal sample and confirmed by real time reverse-transcriptase polymerase chain reaction (rt-PCR). The primary outcomes was 180-day survival after hospital admission. Secondary outcomes were length of ICU and hospital stay, and ICU and in-hospital mortality. A predictive model was developed to estimate the probability of 180-day mortality.

Results

868 patients were included (median age, 64 years [interquartile range [IQR], 56–71 years]; 72% male). Severity at ICU admission, estimated by SAPS3, was 56 points [IQR 50–63]. Prior to intubation, 26% received some type of noninvasive respiratory support. The unadjusted overall 180-day survival rates was 59% (95% CI 56–62%). The predictive factors measured during ICU stay, and associated with 180-day mortality were: age [Odds Ratio [OR] per 1-year increase 1.051, 95% CI 1.033–1.068)), SAPS3 (OR per 1-point increase 1.027, 95% CI 1.011–1.044), diabetes (OR 1.546, 95% CI 1.085–2.204), neutrophils to lymphocytes ratio (OR per 1-unit increase 1.008, 95% CI 1.001–1.016), failed attempt of noninvasive positive pressure ventilation prior to orotracheal intubation (OR 1.878 (95% CI 1.124–3.140), use of selective digestive decontamination strategy during ICU stay (OR 0.590 (95% CI 0.358–0.972) and administration of low dosage of corticosteroids (methylprednisolone 1 mg/kg) (OR 2.042 (95% CI 1.205–3.460).

Conclusion

The long-term survival of mechanically ventilated patients with severe COVID-19 reaches more than 50% and may help to provide individualized risk stratification and potential treatments.

Trial registration: ClinicalTrials.gov Identifier: NCT04379258. Registered 10 April 2020 (retrospectively registered)

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00929-y.

The use of non- invasive ventilation in asthma exacerbation - a two year retrospective analysis of outcomes

Background: The use of Non-Invasive Ventilation (NIV) in acute asthma exacerbation remains controversial. Comparative data on patient characteristics that benefit from NIV in asthma exacerbation to those patients that fail NIV remains limited. Our study compares some of these patient characteristics and examines if NIV is safe and effective in carefully selected patients.

Methods: Following institutional review board approval, we extracted from the electronic medical record and conducted a retrospective chart-based review of those patients who received NIV in the emergency room for a diagnosis of asthma exacerbation from January 2017 to December 2018.

Results and Conclusion: The rate of failure of NIV overall was low, at 9.17%, with younger patients more likely to fail NIV (P = 0.03) and need invasive mechanical ventilation. Surprisingly, baseline asthma severity did not impact NIV failure rate, and neither did body mass index, smoking history, and a host of clinical characteristics. Understandably, the length of stay was significantly longer in the group of patients that failed NIV. There were no adverse events, such as an increased rate of barotrauma events in either group. In conclusion, this study contributes to the growing body of evidence that NIV is a safe and effective adjunct to routine care in the management of patients with asthma exacerbation.

High-flow nasal cannula oxygen therapy and noninvasive ventilation for preventing extubation failure during weaning from mechanical ventilation assessed by lung ultrasound score: A single-center randomized study

BACKGROUND

We sought to demonstrate the superiority of a targeted therapy strategy involving high-flow nasal cannula oxygen (HFNCO₂) therapy and noninvasive ventilation (NIV) using lung ultrasound score (LUS) in comparison with standard care among patients in the intensive care unit (ICU) who undergo successful weaning to decrease the incidence of extubation failure at both 48 hours and seven days.

METHODS

During the study period, 98 patients were enrolled in the study, including 49 in the control group and 49 in the treatment group. Patients in the control group and patients with an LUS score <14 points (at low risk of extubation failure) in the treatment group were extubated and received standard preventive care without NIV or HFNCO₂. Patients with an LUS score ≥14 points (at high risk of extubation failure) in the treatment group were extubated with a second review of the therapeutic optimization to identify and address any persisting risk factors for postextubation respiratory distress; patients received HFNCO₂ therapy combined with sessions of preventive NIV (4-8 hours per day for 4-8 sessions total) for the first 48 hours after extubation.

RESULTS

In the control group, 13 patients had the LUS scores ≥14 points, while 36 patients had scores <14 points. In the treatment group, 16 patients had the LUS scores ≥14 points, while 33 patients had scores <14 points. Among patients with the LUS score ≥14 points, the extubation failure rate within 48 hours was 30.8% in the control group and 12.5% in the treatment group, constituting a statistically significant difference (P<0.05). Conversely, among patients with an LUS score <14 points, 13.9% in the control group and 9.1% in the treatment group experienced extubation failure (P=0.61). The length of ICU stay (9.4±3.1 days vs. 7.2±2.4 days) was significantly different and the re-intubation rate (at 48 hours: 18.4% vs. 10.2%; seven days: 22.4% vs. 12.2%) significantly varied between the two groups (P<0.05). There was no significant difference in the 28-day mortality rate (6.1% vs. 8.2%) between the control and treatment groups.

CONCLUSIONS

Among high-risk adults being weaned from mechanical ventilation and assessed by LUS, the NIV+HFNCO₂ protocol does not lessen the mortality rate but reduce the length of ICU stay, the rate of extubation failure at both 48 hours and seven days.

Factors associated with Noninvasive ventilation compliance in patients with ALS/MND

Background: Although noninvasive ventilation (NIV) improves survival and quality of life (QOL) in ALS, use of NIV is suboptimal. Objective: To determine compliance with "early" NIV initiation, requisite for the feasibility of a large study of early NIV initiation, and examine factors impacting compliance. Methods: Seventy-three ALS participants with forced vital capacities (FVC) >50% were enrolled. Participants with FVC over 80% (Group 1) were initiated on NIV early (FVC between 80 and 85%). Participants with FVC between 50 and 80% (Group 2) started NIV at FVC between 50 and 55%. Symptom surveys, QOL scores, and NIV compliance (machine download documenting use ≥4 hours/night >60% of time) were collected following NIV initiation. Results: 53.6% of Group 1 and 50% of Group 2 were compliant 28 days following NIV initiation, with increased compliance over time. Participants who were unmarried, had lower income, lower educational attainment, or limited caregiver availability were less likely to be compliant. Bothersome symptoms in non-compliant participants included facial air pressure, frequent arousals with difficulty returning to sleep, and claustrophobia. Both compliant and noncompliant participants felt improved QOL with NIV; improvement was significantly greater in compliant participants. Conclusions: These data suggest ALS patients can comply with NIV early in their disease, and potentially benefit as evidenced by improved QOL scores, supporting both feasibility and need for a study comparing early versus late NIV initiation. Moreover, modifiable symptoms were identified that could be optimized to improve compliance. Further studies are needed to determine the impact of "early" intervention on survival and QOL.

The use of head helmets to deliver noninvasive ventilatory support: a comprehensive review of technical aspects and clinical findings

A helmet, comprising a transparent hood and a soft collar, surrounding the patient’s head can be used to deliver noninvasive ventilatory support, both as continuous positive airway pressure and noninvasive positive pressure ventilation (NPPV), the latter providing active support for inspiration. In this review, we summarize the technical aspects relevant to this device, particularly how to prevent CO₂ rebreathing and improve patient–ventilator synchrony during NPPV. Clinical studies describe the application of helmets in cardiogenic pulmonary oedema, pneumonia, COVID-19, postextubation and immune suppression. A section is dedicated to paediatric use. In summary, helmet therapy can be used safely and effectively to provide NIV during hypoxemic respiratory failure, improving oxygenation and possibly leading to better patient-centred outcomes than other interfaces.

Dynamic prediction of late noninvasive ventilation failure in intensive care unit using a time adaptive machine model

BACKGROUND

Noninvasive ventilation (NIV) failure is strongly associated with poor prognosis. Nowadays, plenty of mature studies have been proposed to predict early NIV failure (within 48 hours of NIV), however, the prediction for late NIV failure (after 48 hours of NIV) lacks sufficient research. Late NIV failure delays intubation resulting in the increasing mortality of the patients. Therefore, it is of great significance to expeditiously predict the late NIV failure. In order to dynamically predict late NIV failure, we proposed a Time Updated Light Gradient Boosting Machine (TULightGBM) model.

MATERIAL AND METHODS

In this work, 5653 patients undergoing NIV over 48 hours were extracted from the database of Medical Information Mart for Intensive Care Ⅲ (MIMIC-Ⅲ) for model construction. The TULightGBM model consists of a series of sub-models which learn clinical information from updating data within 48 hours of NIV and integrates the outputs of the sub-models by the dynamic attention mechanism to predict late NIV failure. The performance of the proposed TULightGBM model was assessed by comparison with common models of logistic regression (LR), random forest (RF), LightGBM, eXtreme gradient boosting (XGBoost), artificial neural network (ANN), and long short-term memory (LSTM).

RESULTS

The TULightGBM model yielded prediction results at 8, 16, 24, 36, and 48 hours after the start of the NIV with dynamic AUC values of 0.8323, 0.8435, 0.8576, 0.8886, and 0.9123, respectively. Furthermore, the sensitivity, specificity, and accuracy of the TULightGBM model were 0.8207, 0.8164, and 0.8184, respectively. The proposed model achieved superior performance over other tested models.

CONCLUSIONS

The TULightGBM model is able to dynamically predict the late NIV failure with high accuracy and offer potential decision support for clinical practice.

Predictors of Successful Weaning from Noninvasive Ventilation in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Single-Center Retrospective Cohort Study

Purpose

Noninvasive ventilation (NIV) is often required for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and it can significantly reduce the need for endotracheal intubation. Currently, there is no standard method for predicting successful weaning from NIV. Therefore, we aimed to evaluate whether a weaning index can predict NIV outcomes of patients with AECOPD.

Methods

This study was conducted at a single academic public hospital in northern Taiwan from February 2019 to January 2021. Patients with AECOPD admitted to the hospital with respiratory failure who were treated with NIV were included in the study. Univariate and multivariate logistic regression analyses were used to identify independent predictors of successful weaning from NIV. Receiver operating characteristic curve methodology was used to assess the predictive capacity.

Results

A total of 85 patients were enrolled, 65.9% of whom were successfully weaned from NIV. The patients had a mean age of 75.8 years and were mostly men (89.4%). The rapid shallow breathing index (RSBI) (P < 0.001), maximum inspiratory pressure (P = 0.014), and maximum expiratory pressure (P = 0.004) of the successful group were significant while preparing to wean. The area under the receiver operating characteristic curve for the RSBI was 0.804, which was considered excellent discrimination.

Conclusion

The RSBI predicted successful weaning from NIV in patients with AECOPD with hypercapnic respiratory failure. This index may be useful for selecting patients with AECOPD that are suitable for NIV weaning.

Protocol for assessing mortality reduction with the early use of noninvasive ventilation in prehospital emergency services: A multicentre, observational cohort study in Madrid, Spain

BACKGROUND

Acute respiratory failure (ARF) has become one of the most prevalent serious pathologies encountered in the emergency medical service (EMS). In hospital settings, noninvasive ventilation (NIV) therapy prevents complications from more aggressive treatments for that condition. However, the scarce evidence on the benefits of NIV in prehospital EMS (i.e., during transport to the hospital) is inconclusive.

OBJECTIVES

To determine whether the administration of NIV during prehospital EMS in cases of ARF reduces in-hospital mortality compared with starting NIV on arrival to in-patient EMS.

METHODS

This is a multicentre, observational, prospective cohort study. We recruited a total of 317 patients from the Madrid region (Spain) who were prescribed NIV for their ARF using a nonprobabilistic consecutive sampling method. Analyses of the main outcome (in-hospital mortality) and secondary outcomes (length of hospital stay, readmissions, percentage of intensive care unit admissions, and cost-effectiveness) will include descriptive analyses of patients' characteristics, as well as bivariate and multivariate analyses and cost-effectiveness analysis.

DISCUSSION

This study will provide data on NIV management in prehospital and in-patient EMS in patients with ARF. Results will contribute to the existing evidence on the benefits of NIV in the context of prehospital EMS while underlining the importance of a standardized formal training for physicians and nurses working in prehospital and in-patient EMSs.

CONCLUSION

The VentilaMadrid study will provide valuable data on the clinical factors of patients receiving NIV in prehospital EMS. Further, were our hypothesis to be confirmed, our results would strongly suggest that the administration of NIV in prehospital EMS by medical and nursing profesionals formally trained in the technique reduces mortality and improves prognoses.

Effects of high-flow nasal oxygen cannula versus other noninvasive ventilation in extubated patients: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

A systematic review and meta-analysis were performed to compare the effects of high-flow nasal oxygen cannula (HFNC) and noninvasive ventilation (NIV) in extubated patients with respiratory insufficiency.

METHODS

The Cochrane Library, PubMed, and ClinicalTrials.gov were searched from inception to 28 February 2021, to identify randomized controlled trials. The primary outcome was reintubation within 24-72 hours after a planned extubation. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

RESULTS

Six articles with1746 patients were included. The effect of HFNC on the reintubation rate was noninferior to that of NIV (OR = 1.11, 95% CI: 0.85-1.44). The rate of treatment failure was 20.40% with HFNC versus 20.92% with NIV; this difference was nonsignificant (OR = 0.97, 95% CI: 0.72-1.32, P = 0.85). HFNC reduced the rates of skin lesion occurrence (10.28% versus 23.82%, OR = 0.37, 95% CI: 0.26-0.53, P < 0.00001) and post-extubation respiratory failure (23.76% versus 25.56%, OR = 0.64, 95% CI: 0.46-0.88, P = 0.006), compared with NIV.

CONCLUSIONS

In extubated patients, HFNC was noninferior to NIV in the rate of reintubation and treatment failure. Compared with NIV, HFNC decreased the occurrence of skin lesions and post-extubation respiratory failure.

Non-invasive respiratory support in the management of COVID-19: Report of a series using a nasal CPAP mask

Background

During peak pandemic period of COVID-19, our hospital required rapid reorganization of resources and staff during between mid-March and early April 2020. Within this interval, the hospital responded to an overwhelming rate of admissions of patients in respiratory failure, rapidly reaching over 95% of its usual inpatient bed capacity and requiring 70 extra critical care beds and at least 40 intermediate care unit beds. This created a significant shortage of materials including ventilation equipment, requiring improvised use of available resources.

Aims

To describe our use of non-invasive ventilation (NIV) with the continuous positive nasal airway pressure (CPAP) device SuperNO2VA™ (Vyaire Medical, Mettawa, IL) with hospitalized patients in acute respiratory failure due to presumed COVID-19.

Methods

We performed a retrospective analysis of 14 inpatients receiving NIV CPAP at the Hospital Ramón y Cajal in Madrid, Spain. These were inpatients presenting in respiratory failure during the peak pandemic period based on defined respiratory health, oxygenation, and comorbidity status criteria. Patient data were retrospectively acquired from patient medical records.

Results

All 14 patients were reviewed. Our series consisted of 11 males and three females with an average age of 61.5 years. Ten of 14 patients (71.4%) NIV CPAP patients did not require intubation or reintubation. Of the four unsuccessful cases, one required intubation, two required reintubation, and one expired.

Conclusions

In a time of crisis, anesthesiologists and respiratory specialists implemented the use of NIV CPAP with SuperNO2VA to help meet the high care demand of patients in respiratory distress. Although the SuperNO2VA was not originally developed for the management of patients in respiratory failure or distress related to COVID-19, this case series demonstrates it can be used with mostly favorable results during a time of limited resources to improve the clinical situation in patients. Advantages and disadvantages are explored.

Effectiveness and safety of noninvasive positive pressure ventilation in the treatment of COVID-19-associated acute hypoxemic respiratory failure: a single center, non-ICU setting experience

The role of noninvasive positive pressure ventilation (NIPPV) in COVID-19 patients with acute hypoxemic respiratory failure (AHRF) is uncertain, as no direct evidence exists to support NIPPV use in such patients. We retrospectively assessed the effectiveness and safety of NIPPV in a cohort of COVID-19 patients consecutively admitted to the COVID-19 general wards of a medium-size Italian hospital, from March 6 to May 7, 2020. Healthcare workers (HCWs) caring for COVID-19 patients were monitored, undergoing nasopharyngeal swab for SARS-CoV-2 in case of onset of COVID-19 symptoms, and periodic SARS-CoV-2 screening serology. Overall, 50 patients (mean age 74.6 years) received NIPPV, of which 22 (44%) were successfully weaned, avoiding endotracheal intubation (ETI) and AHRF-related death. Due to limited life expectancy, 25 (50%) of 50 NIPPV-treated patients received a "do not intubate" (DNI) order. Among these, only 6 (24%) were weaned from NIPPV. Of the remaining 25 NIPPV-treated patients without treatment limitations, 16 (64%) were successfully weaned, 9 (36%) underwent delayed ETI and, of these, 3 (33.3%) died. NIPPV success was predicted by the use of corticosteroids (OR 15.4, CI 1.79-132.57, p 0.013) and the increase in the PaO₂/FiO₂ ratio measured 24-48 h after NIPPV initiation (OR 1.02, CI 1-1.03, p 0.015), while it was inversely correlated with the presence of a DNI order (OR 0.03, CI 0.001-0.57, p 0.020). During the study period, 2 of 124 (1.6%) HCWs caring for COVID-19 patients were diagnosed with SARS-CoV-2 infection. Apart from patients with limited life expectancy, NIPPV was effective in a substantially high percentage of patients with COVID-19-associated AHRF. The risk of SARS-CoV-2 infection among HCWs was low.

Noninvasive respiratory support outside the intensive care unit for acute respiratory failure related to coronavirus-19 disease: a systematic review and meta-analysis

BACKGROUND

Noninvasive respiratory support (NIRS) has been diffusely employed outside the intensive care unit (ICU) to face the high request of ventilatory support due to the massive influx of patients with acute respiratory failure (ARF) caused by coronavirus-19 disease (COVID-19). We sought to summarize the evidence on clinically relevant outcomes in COVID-19 patients supported by NIV outside the ICU.

METHODS

We searched PUBMED®, EMBASE®, and the Cochrane Controlled Clinical trials register, along with medRxiv and bioRxiv repositories for pre-prints, for observational studies and randomized controlled trials, from inception to the end of February 2021. Two authors independently selected the investigations according to the following criteria: (1) observational study or randomized clinical trials enrolling ≥ 50 hospitalized patients undergoing NIRS outside the ICU, (2) laboratory-confirmed COVID-19, and (3) at least the intra-hospital mortality reported. Preferred Reporting Items for Systematic reviews and Meta-analysis guidelines were followed. Data extraction was independently performed by two authors to assess: investigation features, demographics and clinical characteristics, treatments employed, NIRS regulations, and clinical outcomes. Methodological index for nonrandomized studies tool was applied to determine the quality of the enrolled studies. The primary outcome was to assess the overall intra-hospital mortality of patients under NIRS outside the ICU. The secondary outcomes included the proportions intra-hospital mortalities of patients who underwent invasive mechanical ventilation following NIRS failure and of those with 'do-not-intubate' (DNI) orders.

RESULTS

Seventeen investigations (14 peer-reviewed and 3 pre-prints) were included with a low risk of bias and a high heterogeneity, for a total of 3377 patients. The overall intra-hospital mortality of patients receiving NIRS outside the ICU was 36% [30-41%]. 26% [21-30%] of the patients failed NIRS and required intubation, with an intra-hospital mortality rising to 45% [36-54%]. 23% [15-32%] of the patients received DNI orders with an intra-hospital mortality of 72% [65-78%]. Oxygenation on admission was the main source of between-study heterogeneity.

CONCLUSIONS

During COVID-19 outbreak, delivering NIRS outside the ICU revealed as a feasible strategy to cope with the massive demand of ventilatory assistance.

REGISTRATION

PROSPERO, https://www.crd.york.ac.uk/prospero/ , CRD42020224788, December 11, 2020.

Continuous estimation of airway resistance in non-invasive ventilation

BACKGROUND

This study aimed to evaluate the accuracy of expiratory time constant (RC_exp) to continuously calculate the airway resistance (R_aw).

MATERIAL AND METHODS

A Respironics V60 ventilator was connected to a lung simulator for modeling different profiles of respiratory mechanics.

RESULTS

During assisted ventilation, the respiratory system compliance (C_rs) calculation was always overestimated in most lung models. The R_aw estimation using the expiratory resistance (R_exp) method was close to the calculated value with the occlusion method during volume-controlled ventilation (VCV). In expiratory flow limitation (EFL) lung models, similar results were obtained in the estimation of inspiratory resistance (R_insp), but different variations were observed in the calculation of the R_exp. The results estimated with RC_exp and with dynamic signal analysis had significant variation and accuracy (p < 0.001).

CONCLUSION

The RC_exp method is a robust approach to provide real-time assessments of R_insp and R_exp in spontaneously breathing patients during noninvasive ventilation. An underestimation of R_exp was observed in EFL lung models.

Association between increased nonaerated lung weight and treatment failure in patients with de novo acute respiratory failure: Difference between high-flow nasal oxygen therapy and noninvasive ventilation in a multicentre retrospective study

PURPOSE

To determine the association between lung collapse and treatment failure in high-flow nasal cannula oxygen therapy (HFNC) or noninvasive ventilation (NIV).

METHODS

We performed a quantitative analysis of chest computed tomography in patients with de novo acute respiratory failure who received HFNC (HFNC group) or NIV (NIV group) between January 2012 and December 2017. In the HFNC and NIV group, the nonaerated lung weight were compared between patients in whom respiratory treatment succeeded or failed, respectively. We used logistic regression to examine the association between the nonaerated lung weight and treatment failure.

RESULTS

Treatment failed in 70/118 (59%) patients in the HFNC group and 66/101 (65%) patients in the NIV group. The nonaerated lung weight was significantly greater in unsuccessfully treated patients than in successfully treated patients in the HFNC group (p = 0.005), but not in the NIV group (p = 0.535). Logistic regression revealed that greater nonaerated lung weight was associated with increased risk of HFNC failure (adjusted odds ratio 1.30 per 5% increase, 95% confidence interval 1.09-1.55, p = 0.003) but not of NIV failure.

CONCLUSIONS

Patients with a greater nonaerated lung weight had a higher risk of HFNC failure, but not of NIV failure.

Effect of one-year dextromethorphan/quinidine treatment on management of respiratory impairment in amyotrophic lateral sclerosis

Treatment with Dextromethorphan/Quinidine (DM/Q) has demonstrated benefit on pseudobulbar affect and bulbar function in amyotrophic lateral sclerosis (ALS). The aim of this study was to assess whether DM/Q could provide long-term improvement in bulbar function and thereby prolong noninvasive respiratory management in ALS.

MATERIALS AND METHODS

This prospective, case-cohort study, recruited ALS patients with bulbar dysfunction. Subjects included were compared with cross-matched historical controls. Cases received DM/Q (20/10 mg twice daily) during one-year follow-up; bulbar dysfunction was evaluated with the Norris scale bulbar subscore (NBS) and bulbar subscale of AlSFRS-R (ALSFRSb).

RESULTS

In total, 21 cases and 20 controls were enrolled, of whom noninvasive respiratory muscle assistance failed in 6 (28.5%) patients in the DM/Q group, compared with 4 patients (20.0%) in the control group (p = 0.645). Time from study onset to failure of respiratory muscle aids was 5.50 + 1.31 months in the DM/Q group and 5.20 + 1.15 months in the control group (p = 0.663). The adjusted OR for the effect of treatment on failure of noninvasive respiratory muscle aids was 2.12 (95%CI 0.23-33.79, p = 0.592). In the DM/Q group an impairment in scores was found in NBS (F = 19.26, p = 0.000) and ALSFRS-Rb (F = 12.71, p = 0.001) across different months of the study.

CONCLUSION

Treatment with DM/Q in ALS is unable to prolong noninvasive respiratory management, and moreover, has no effect on long-term deterioration of bulbar function. Notwithstanding the results on bulbar function, DM/Q was found to improve pseudobulbar affect during one-year follow-up.

High flow nasal cannula for adult acute hypoxemic respiratory failure in the ED setting: A narrative review

Introduction

High flow nasal cannula (HFNC) is a noninvasive ventilation (NIV) system that has demonstrated promise in the emergency department (ED) setting.

Objective

This narrative review evaluates the utility of HFNC in adult patients with acute hypoxemic respiratory failure in the ED setting.

Discussion

HFNC provides warm (37 °C), humidified (100% relative humidity) oxygen at high flows with a reliable fraction of inspired oxygen (FiO₂). HFNC can improve oxygenation, reduce airway resistance, provide humidified flow that can flush anatomical dead space, and provide a low amount of positive end expiratory pressure. Recent literature has demonstrated efficacy in acute hypoxemic respiratory failure, including pneumonia, acute respiratory distress syndrome (ARDS), coronavirus disease 2019 (COVID-19), interstitial lung disease, immunocompromised states, the peri-intubation state, and palliative care, with reduced need for intubation, length of stay, and mortality in some of these conditions. Individual patient factors play an important role in infection control risks with respect to the use of HFNC in patients with COVID-19. Appropriate personal protective equipment, adherence to hand hygiene, surgical mask placement over the HFNC device, and environmental controls promoting adequate room ventilation are the foundation for protecting healthcare personnel. Frequent reassessment of the patient placed on HFNC is necessary; those with severe end organ dysfunction, thoracoabdominal asynchrony, significantly increased respiratory rate, poor oxygenation despite HFNC, and tachycardia are at increased risk of HFNC failure and need for further intervention.

Conclusions

HFNC demonstrates promise in several conditions requiring respiratory support. Further randomized trials are needed in the ED setting.

[Influence of nurses on the experience of noninvasive ventilation]

Noninvasive ventilation (NIV) is established as an integral part of intensive care therapy for respiratory insufficiency. However, it is associated with restrictions on patient autonomy and comfort. A successful course of therapy is largely dependent on the acceptance and adherence of the patients concerned. Intensive care nurses can have a significant influence on the success of the therapy by dealing with the subjective experience of the patients and by maintaining close contact with them. The prerequisite for this is profound knowledge of the different technical aspects of therapy and equipment as well as positive and negative factors influencing NIV tolerance in order to be able to offer and implement an individual intervention.

Oxygenation strategies after extubation of critically ill and postoperative patients

In intensive care units (ICUs), the decision to extubate is a critical one because mortality is particularly high in case of reintubation. Around 15% of patients ready to be weaned off a ventilator experience extubation failure leading to reintubation. The use of high-flow nasal oxygen and non-invasive ventilation are two alternatives of standard oxygen supplementation that may help to prevent reintubation. High-flow nasal oxygen and non-invasive ventilation, may be used to prevent reintubation in patients with low (e.g., patients without comorbidities and with short durations of mechanical ventilation) and high risk (e.g., patients >65 years and those with underlying cardiac disease, chronic respiratory disorders, and/or hypercapnia at the time of extubation) of reintubation, respectively. However, non-invasive ventilation used as a rescue therapy to treat established post-extubation respiratory failure could increase mortality by delaying reintubation, and should therefore be used very carefully in this setting. The oxygenation strategy to be applied in postoperative patients is different from the patients who are extubated in the ICUs. Standard oxygen after a surgical procedure is adequate, even following major abdominal or cardiothoracic surgery, but should probably be switched to high-flow nasal oxygen in patients with hypoxemic. Unlike in patients experiencing post-extubation respiratory failure in ICUs wherein non-invasive ventilation may have deleterious effects, it may actually improve the outcomes in postoperative patients with respiratory failure. This review discusses the different clinical situations with the aim of choosing the most effective oxygenation strategy to prevent post-extubation respiratory failure and to avoid reintubation.

High-Dose Nitroglycerin Bolus for Sympathetic Crashing Acute Pulmonary Edema: A Prospective Observational Pilot Study

BACKGROUND

Sympathetic crashing acute pulmonary edema (SCAPE) is a severe form of hypertensive acute heart failure with a dramatic presentation. Rapid identification and management in the emergency department (ED) is key to saving these patients and preventing morbidity associated with endotracheal intubation and intensive care treatment. Use of high-dose nitroglycerin (NTG) and noninvasive ventilation (NIV) has been advocated in management of such patients.

OBJECTIVE

To study the feasibility and safety of high-dose NTG combined with NIV in SCAPE.

METHODS

This was a prospective observational pilot study done in the ED of a tertiary care hospital. All patients were treated with high-dose NTG and NIV. The primary objective was to study the feasibility and safety of the SCAPE management protocol in terms of the outcome of the patient. Resolution of symptoms in 6 h and need for intubation were recorded as endpoints. Any complications associated with high-dose NTG were also recorded.

RESULTS

A total of 25 patients were recruited. The mean bolus dose of NTG given was 872 μg, and mean cumulative dose, 35 mg. There was no incidence of hypotension after the bolus dose of nitroglycerin. Eleven patients had resolution of symptoms at 3 h of therapy. Twenty-four patients were discharged from the ED itself after a brief period of observation, and one patient was intubated and shifted to the intensive care unit.

CONCLUSION

Use of our specific SCAPE treatment algorithm, which included high-dose NTG and NIV, was safe and provided rapid resolution of symptoms.

Management of respiratory distress following prehospital implementation of noninvasive ventilation in a physician-staffed emergency medical service: a single-center retrospective study

BACKGROUND

Noninvasive ventilation (NIV) is recognized as first line ventilatory support for the management of acute pulmonary edema (APE) and chronic obstructive pulmonary disease (COPD) exacerbations. We aimed to study the prehospital management of patients in acute respiratory distress with an indication for NIV and whether they received it or not.

METHODS

This retrospective study included patients ≥18 years old who were cared for acute respiratory distress in a prehospital setting. Indications for NIV were oxygen saturation (SpO₂) <90% and/or respiratory rate (RR) >25/min with a presumptive diagnosis of APE or COPD exacerbation. Study population characteristics, initial and at hospital vital signs, presumptive and definitive diagnosis were analyzed. For patients who received NIV, dyspnea level was evaluated with a dyspnea verbal ordinal scale (D-VOS, 0-10) and arterial blood gas (ABG) values were obtained at hospital arrival.

RESULTS

Among the 187 consecutive patients included in the study, most (n = 105, 56%) had experienced APE or COPD exacerbation, and 56 (30%) received NIV. In comparison with patients without NIV, those treated with NIV had a higher initial RR (35 ± 8/min vs 29 ± 10/min, p < 0.0001) and a lower SpO₂ (79 ± 10 vs 88 ± 11, p < 0.0001). The level of dyspnea was significantly reduced for patients treated with NIV (on-scene D-VOS 8.4 ± 1.7 vs 4.4 ± 1.8 at admission, p < 0.0001). Among the 131 patients not treated with NIV, 41 (31%) had an indication. In the latter group, initial SpO₂ was 80 ± 10% in the NIV group versus 86 ± 11% in the non-NIV group (p = 0.0006). NIV was interrupted in 9 (16%) patients due to either discomfort (n = 5), technical problem (n = 2), persistent desaturation (n = 1), or vomiting (n = 1).

CONCLUSIONS

The results of this study contribute to a better understanding of the prehospital management of patients who present with acute respiratory distress and an indication for NIV. NIV was started on clinically more severe patients, even if predefined criteria to start NIV were present. NIV allows to improve vital signs and D-VOS in those patients. A prospective study could further elucidate why patients with a suspected diagnosis of APE and COPD are not treated with NIV, as well as the clinical impact of the different strategies.

TRIAL REGISTRATION

The study was approved by our institutional ethical committee ( CER-VD 2020-01363 ).

Non-invasive ventilation versus high-flow nasal oxygen for postextubation respiratory failure in ICU: a post-hoc analysis of a randomized clinical trial

Background

In intensive care units (ICUs), patients experiencing post-extubation respiratory failure have poor outcomes. The use of noninvasive ventilation (NIV) to treat post-extubation respiratory failure may increase the risk of death. This study aims at comparing mortality between patients treated with NIV alternating with high-flow nasal oxygen or high-flow nasal oxygen alone.

Methods

Post-hoc analysis of a multicenter, randomized, controlled trial focusing on patients who experienced post-extubation respiratory failure within the 7 days following extubation. Patients were classified in the NIV group or the high-flow nasal oxygen group according to oxygenation strategy used after the onset of post-extubation respiratory failure. Patients reintubated within the first hour after extubation and those promptly reintubated without prior treatment were excluded. The primary outcome was mortality at day 28 after the onset of post-extubation respiratory failure.

Results

Among 651 extubated patients, 158 (25%) experienced respiratory failure and 146 were included in the analysis. Mortality at day 28 was 18% (15/84) using NIV alternating with high-flow nasal oxygen and 29% (18/62) with high flow nasal oxygen alone (difference, − 11% [95% CI, − 25 to 2]; p = 0.12). Among the 46 patients with hypercapnia at the onset of respiratory failure, mortality at day 28 was 3% (1/33) with NIV and 31% (4/13) with high-flow nasal oxygen alone (difference, − 28% [95% CI, − 54 to − 6]; p = 0.006). The proportion of patients reintubated 48 h after the onset of post-extubation respiratory failure was 44% (37/84) with NIV and 52% (32/62) with high-flow nasal oxygen alone (p = 0.21).

Conclusions

In patients with post-extubation respiratory failure, NIV alternating with high-flow nasal oxygen might not increase the risk of death.

Trial registration number

The trial was registered at http://www.clinicaltrials.gov with the registration number NCT03121482 the 20th April 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03621-6.