Benefits of non-invasive ventilation in acute hypercapnic respiratory failure

Incidence and risk factors of postoperative pulmonary complications following total hip arthroplasty revision: a retrospective Nationwide Inpatient Sample database study

BACKGROUND

Postoperative pulmonary complications (PPCs) are among the most severe complications following total hip arthroplasty revision (THAR), imposing significant burdens on individuals and society. This study examined the prevalence and risk factors of PPCs following THAR using the NIS database, identifying specific pulmonary complications (SPCs) and their associated risks, including pneumonia, acute respiratory failure (ARF), and pulmonary embolism (PE).

METHODS

The National Inpatient Sample (NIS) database was used for this cross-sectional study. The analysis included patients undergoing THAR based on NIS from 2010 to 2019. Available data include demographic data, diagnostic and procedure codes, total charges, length of stay (LOS), hospital information, insurance information, and discharges.

RESULTS

From the NIS database, a total of 112,735 THAR patients in total were extracted. After THAR surgery, there was a 2.62% overall incidence of PPCs. Patients with PPCs after THAR demonstrated increased LOS, total charges, usage of Medicare, and in-hospital mortality. The following variables have been determined as potential risk factors for PPCs: advanced age, pulmonary circulation disorders, fluid and electrolyte disorders, weight loss, congestive heart failure, metastatic cancer, other neurological disorders (encephalopathy, cerebral edema, multiple sclerosis etc.), coagulopathy, paralysis, chronic pulmonary disease, renal failure, acute heart failure, deep vein thrombosis, acute myocardial infarction, peripheral vascular disease, stroke, continuous trauma ventilation, cardiac arrest, blood transfusion, dislocation of joint, and hemorrhage.

CONCLUSIONS

Our study revealed a 2.62% incidence of PPCs, with pneumonia, ARF, and PE accounting for 1.24%, 1.31%, and 0.41%, respectively. A multitude of risk factors for PPCs were identified, underscoring the importance of preoperative optimization to mitigate PPCs and enhance postoperative outcomes.

Effects of high-flow nasal cannula oxygen therapy in bronchiectasis and hypercapnia: a retrospective observational study

BACKGROUND

The effectiveness of high-flow nasal cannula (HFNC) therapy in patients with bronchiectasis experiencing hypercapnia remains unclear. Our aim was to retrospectively analyze the short-term outcomes of HFNC therapy in such patients, and to further explore the predictors of HFNC treatment failure in this particular patient population.

METHODS

A retrospective review was conducted on patients with bronchiectasis who received HFNC (n = 70) for hypercapnia (arterial partial pressure of carbon dioxide, PaCO2 ≥ 45 mmHg) between September 2019 and September 2023.

RESULTS

In the study population, 30% of patients presented with acidemia (arterial pH < 7.35) at baseline. Within 24 h of HFNC treatment, there was a significant reduction in PaCO2 levels by a mean of 4.0 ± 12.7 mmHg (95% CI -7.0 to -1.0 mmHg). Concurrently, arterial pH showed a statistically significant increase with a mean change of 0.03 ± 0.06 (95% CI 0.01 to 0.04). The overall hospital mortality rate in our study was 17.5%. The median length of hospital stay was 11.0 days (interquartile range [IQR] 8.0 to 16.0 days). Sub-analysis revealed no statistically significant differences in hospital mortality (19.0% vs. 20.4%, p = 0.896), length of hospital stay (median 14.0 days [IQR 9.0 to 18.0 days] vs. 10.0 days [IQR 7.0 to 16.0 days], p = 0.117) and duration of HFNC application (median 5.0 days [IQR 2.0 to 8.5 days] vs. 6.0 days [IQR 4.9 to 9.5 days], p = 0.076) between the acidemia group and the non-acidemia group (arterial pH ≥ 7.35). However, more patients in the non-acidemia group had do-not-intubate orders. The overall treatment failure rate for HFNC was 28.6%. Logistic regression analysis identified the APACHE II score (OR 1.24 per point) as the independent predictor of HFNC failure.

CONCLUSIONS

In patients with bronchiectasis and hypercapnia, HFNC as an initial respiratory support can effectively reduce PaCO2 level within 24 h of treatment. A high APACHE II score has emerged as a prognostic indicator for HFNC treatment failure. These observations highlight randomized controlled trials to meticulously evaluate the efficacy of HFNC in this specific population.

Development of respiratory care guidelines for Duchenne muscular dystrophy in the UK: key recommendations for clinical practice

Significant inconsistencies in respiratory care provision for Duchenne muscular dystrophy (DMD) are reported across different specialist neuromuscular centres in the UK. The absence of robust clinical evidence and expert consensus is a barrier to the implementation of care recommendations in public healthcare systems as is the need to increase awareness of key aspects of care for those living with DMD. Here, we provide evidenced-based and/or consensus-based best practice for the respiratory care of children and adults living with DMD in the UK, both as part of routine care and in an emergency.

METHODOLOGY

Initiated by an expert working group of UK-based respiratory physicians (including British Thoracic Society (BTS) representatives), neuromuscular clinicians, physiotherapist and patient representatives, draft guidelines were created based on published evidence, current practice and expert opinion. After wider consultation with UK respiratory teams and neuromuscular services, consensus was achieved on these best practice recommendations for respiratory care in DMD.

RESULT

The resulting recommendations are presented in the form of a flow chart for assessment and monitoring, with additional guidance and a separate chart setting out key considerations for emergency management. The recommendations have been endorsed by the BTS.

CONCLUSIONS

These guidelines provide practical, reasoned recommendations for all those managing day-to-day and acute respiratory care in children and adults with DMD. The hope is that this will support patients and healthcare professionals in accessing high standards of care across the UK.

Sedation and analgesia strategies for non-invasive mechanical ventilation: A systematic review and meta-analysis

BACKGROUND

The use of sedative and analgesic drugs during non-invasive ventilation (NIV) in patients with acute respiratory failure (ARF) is controversial.

OBJECTIVES

To assess the clinical effectiveness of sedative and analgesic medications used during NIV for patients with ARF to no sedation or analgesia. In addition, to investigate the characteristics of dexmedetomidine in comparison to other medications.

METHODS

PubMed, Embase, Web of Science, Cochrane Library and China National Knowledge Infrastructure (CNKI) were searched. Mean differences (MDs) or pooled risk ratios (RRs) were computed using random-effects models. We applied the Cochrane risk-of-bias assessment tool 2.0 to assess the methodological quality of eligible studies and the GRADE approach to evaluate the evidence certainty.

RESULTS

Twenty-one studies were selected. Whether in Group A (using sedative and analgesic drugs vs. nonuse) or Group B (using dexmedetomidine vs. other drugs), the rates of tracheal intubation and delirium, the length of NIV, and the length of stay in the intensive care unit (ICU LOS) all decreased in both experimental groups (P < 0.05). And there were no significant differences in all-cause mortality and the incidence of hypotension between the two groups (P > 0.05), while both Group A and Group B's experimental groups had greater incidences of bradycardia.

CONCLUSIONS

Administering sedative and analgesic medications during NIV can reduce the risk of tracheal intubation and delirium. Additionally, dexmedetomidine outperformed other sedative medications in terms of these clinical outcomes, making it the better option when closely monitoring patients' vital signs.

The Association between Non-Invasive Ventilation and the Rate of Ventilator-Associated Pneumonia

Ventilator-associated pneumonia (VAP) has significant effects on patient outcomes, including prolonging the duration of both mechanical ventilation and stay in the intensive care unit (ICU). The aim of this study was to assess the association between non-invasive ventilation/oxygenation (NIVO) prior to intubation and the rate of subsequent VAP. This was a multicenter retrospective cohort study of adult patients who were admitted to the medical ICU from three tertiary care academic centers in three distinct regions. NIVO was defined as continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), or high-flow nasal cannula (HFNC) for any duration during the hospitalization prior to intubation. The primary outcome variable was VAP association with NIVO. A total of 17,302 patients were included. VAP developed in 2.6% of the patients (444/17,302), 2.3% (285/12,518) of patients among those who did not have NIVO, 1.6% (30/1879) of patients who had CPAP, 2.5% (17/690) of patients who had HFNC, 8.1% (16/197) of patients who had BiPAP, and 4.8% (96/2018) of patients who had a combination of NIVO types. Compared to those who did not have NIVO, VAP was more likely to develop among those who had BiPAP (adj OR 3.11, 95% CI 1.80-5.37, p < 0.001) or a combination of NIVO types (adj OR 1.91, 95% CI 1.49-2.44, p < 0.001) after adjusting for patient demographics and comorbidities. The use of BiPAP or a combination of NIVO types significantly increases the odds of developing VAP once receiving IMV.

Acceptance and adherence to non-invasive positive pressure ventilation in people with chronic obstructive pulmonary disease: a grounded theory study

Introduction

Non-Invasive Positive Pressure Ventilation (NPPV) is an established treatment for people with Chronic Obstructive Pulmonary Disease (COPD), but it is often improperly used or rejected. The patterns of acceptance and adherence to NPPV, conceiving constraints, and strengths related to its adaptation have not been explored from a qualitative perspective yet.

Objectives

This study aims to qualitatively explore patterns of adaptation to NPPV in people affected by COPD and to identify the core characteristics and the specific adaptive challenges during the adaptation process.

Methods

Forty-two people with moderate or severe COPD were recruited and 336 unstructured interviews were conducted. A Constructivist Grounded Theory was used to gather and analyze data: the transcriptions were mutually gathered in open, selective, and theoretical phases, with open, selective, and theoretical coding, respectively.

Results

The analysis resulted in a non-linear and dynamic process, characterized by three phases: deciding, trying NPPV, and using NPPV. The patterns revealed that positive and negative NPPV experiences, together with beliefs, emotions, stressful mental states, and behaviors result in different acceptance and adherence rates.

Discussions

These findings may be helpful to implement new care strategies to promote acceptance and adherence to NPPV.

Acute dyspnea in the emergency department: a clinical review

Acute dyspnea represents one of the most frequent symptoms leading to emergency room evaluation. Its significant prognostic value warrants a careful evaluation. The differential diagnosis of dyspnea is complex due to the lack of specificity and the loose association between its intensity and the severity of the underlying pathological condition. The initial assessment of dyspnea calls for prompt diagnostic evaluation and identification of optimal monitoring strategy and provides information useful to allocate the patient to the most appropriate setting of care. In recent years, accumulating evidence indicated that lung ultrasound, along with echocardiography, represents the first rapid and non-invasive line of assessment that accurately differentiates heart, lung or extra-pulmonary involvement in patients with dyspnea. Moreover, non-invasive respiratory support modalities such as high-flow nasal oxygen and continuous positive airway pressure have aroused major clinical interest, in light of their efficacy and practicality to treat patients with dyspnea requiring ventilatory support, without using invasive mechanical ventilation. This clinical review is focused on the pathophysiology of acute dyspnea, on its clinical presentation and evaluation, including ultrasound-based diagnostic workup, and on available non-invasive modalities of respiratory support that may be required in patients with acute dyspnea secondary or associated with respiratory failure.

Comparison of High Flow Nasal Therapy with Non-Invasive Ventilation and Conventional Oxygen Therapy for Acute Hypercapnic Respiratory Failure: A Meta-Analysis of Randomized Controlled Trials

Purpose

We aimed to evaluate whether high flow nasal cannula (HFNC) is an effective and safe method for adult patients with acute hypercapnic respiratory failure (AHRF).

Methods

We searched the Cochrane Library, Embase, and PubMed databases from inception to August 2022 to obtain randomized controlled trials (RCTs) that compared HFNC with conventional oxygen treatment (COT) or non-invasive ventilation (NIV) in patients with AHRF, and then performed a meta-analysis.

Results

A total of ten parallel RCTs with 1265 individuals were identified. Of them, two studies compared HFNC with COT and eight studies compared HFNC with NIV. In terms of intubation rate, mortality, and arterial blood gas (ABG) improvement, HFNC showed comparable effects to NIV and COT. However, HFNC was more comfortable (mean difference [MD] -1.87, 95% confidence interval [CI] =-2.59, -1.15, P <0.00001, I2 =0%) and resulted in fewer adverse events (odds ratio [OR] 0.12, 95% CI=0.06, 0.28, P<0.00001, I2 = 0%), compared with NIV. In comparison to NIV, HFNC could significantly lower heart rate (HR) (MD -4.66, 95% CI=-6.82, -2.50, P <0.0001, I2 =0%), respiratory rate (RR) (MD -1.17, 95% CI=-2.03, -0.31, P =0.008, I2 =0%), and hospital stay length (MD -0.80, 95% CI=-1.44, -0.16, P =0.01, I2 =0%). NIV showed a decreased frequency in the treatment crossover rate, compared with HFNC in patients with pH<7.30 (OR 5.78, 95% CI=1.50, 22.31, P = 0.01, I2: not applicable). Contrary to COT, HFNC could considerably reduce the need for NIV (OR 0.57, 95% CI=0.35, 0.91, P=0.02, I2=0%).

Conclusion

HFNC was effective and safe in patients with AHRF. However, in patients with pH <7.30, HFNC may result in a higher incidence of treatment crossover, compared with NIV. Compared to COT, HFNC may decrease the need for NIV in patients with compensated hypercapnia.

Hypoxische, anämische und kardial bedingte Hypoxämie: Wann beginnt die Hypoxie im Gewebe?

Bei einer Hypoxämie ist oft der Sauerstoffgehalt noch im unteren Normbereich, sodass keine Hypoxie im Gewebe vorliegt. Wird die Hypoxie-Schwelle im Gewebe bei einer hypoxisch, anämisch und auch kardial bedingten Hypoxämie erreicht, kommt es im Zellstoffwechsel, unabhängig von der Genese, zu identischen Gegenregulationen. Im klinischen Alltag wird diese pathophysiologische Tatsache mitunter ignoriert, obwohl je nach Hypoxämie-Ursache die Beurteilung und die Therapie stark unterschiedlich sind. Während für die anämische Hypoxämie restriktive und allgemein akzeptierte Regeln in den Transfusionsrichtlinien festgelegt sind, wird bei einer hypoxischen Hypoxie früh die Indikation zu einer meist invasiven Beatmung gestellt. Die klinische Beurteilung und Indikationsstellung fokussiert dabei auf die Parameter Sauerstoffsättigung, Sauerstoffpartialdruck und Oxygenierungsindex. Während der Corona-Pandemie sind Fehlinterpretationen der Pathophysiologie sichtbar geworden und haben vermutlich zu überflüssigen Intubationen geführt. Für die Behandlung einer hypoxischen Hypoxie mittels invasiver Beatmung aber gibt es keine Evidenz. Im vorliegenden Review wird auf die Pathophysiologie der verschiedenen Hypoxieursachen unter besonderer Berücksichtigung der Intubation und Beatmung auf der Intensivstation eingegangen.

[Recent research on extracorporeal carbon dioxide removal]

Extracorporeal carbon dioxide removal is an artificial lung auxiliary technique based on extrapulmonary gas exchange and can effectively remove carbon dioxide and provide oxygenation to a certain extent, and it is one of the effective treatment techniques for hypercapnia developed after mechanical ventilation and extracorporeal membrane oxygenation in recent years and has wide application prospect. This article elaborates on the development, working principle, advantages, classification, complications, and clinical application of extracorporeal carbon dioxide removal, so as to provide a new choice for extracorporeal carbon dioxide removal in clinical practice.

Characteristics and outcomes of patients with chronic obstructive pulmonary disease admitted to the intensive care unit due to acute hypercapnic respiratory failure

BACKGROUND

The study aimed to describe the clinical course, outcomes, and prognostic factors of chronic obstructive pulmonary disease (COPD) patients with acute hypercapnic respiratory failure.

METHODS

This retrospective study involved patients with acute hypercapnic respiratory failure due to COPD of any cause admitted to the intensive care unit (ICU) for non-invasive or invasive mechanical ventilation (IMV) support between December 2015 and February 2020.

RESULTS

One hundred patients were evaluated. The main causes of acute hypercapnic respiratory failure were bronchitis, pneumonia, and heart failure. The patients' mean Acute Physiology and Chronic Health Evaluation (APACHE) II score was 23.0±7.2, and their IMV rate was 43%. ICU, in-hospital, and 90-day mortality rates were 21%, 29%, and 39%, respectively. Non-survivors had more pneumonia, shock within the first 24 hours of admission, IMV, vasopressor use, and renal replacement therapy, along with higher APACHE II scores, lower admission albumin levels and PaO2/ FiO2 ratios, and longer ICU and hospital stays than survivors. Logistic regression analysis identified APACHE II score (odds ratio [OR], 1.157; 95% confidence interval [CI], 1.017-1.317; P=0.026), admission PaO2/FiO2 ratio (OR, 0.989; 95% CI, 0.978-0.999; P=0.046), and vasopressor use (OR, 8.827; 95% CI, 1.650-47.215; P=0.011) as predictors of ICU mortality. APACHE II score (OR, 1.099; 95% CI, 1.021-1.182; P=0.011) and admission albumin level (OR, 0.169; 95% CI, 0.056-0.514; P=0.002) emerged as predictors of 90-day mortality.

CONCLUSIONS

APACHE II scores, the PaO2/FiO2 ratio, vasopressor use, and albumin levels are significant short-term mortality predictors in severely ill COPD patients with acute hypercapnic respiratory failure.

[The role of HFNC oxygen in pre-oxygenation prior to intubation and the practice of invasive procedures]

Over recent years, High Flow Nasal Cannula (HFNC) oxygen therapy has been more and more extensively applied in numerous medical settings, and it is now carried out in invasive procedures such as pre-oxygenation before orotracheal intubation, often leading to complications. More generally, pre-oxygenation is aimed at maintaining the highest possible oxygen saturation for extended periods of time. With this in mind, HFNC seems as effective as standard oxygen delivery with regard to hematosis in patients with mild or moderate hypoxemia, and it presents the advantage of reducing the adverse events associated with intubation. That said, during pre-oxygenation of patients with severe hypoxemia, non-invasive ventilation (NIV) is probably more effective than HFNC, especially in the prevention of respiratory events. However, in patients with little or no hypoxemia undergoing risky procedures such as bronchial endoscopy, HFNC allows better oxygen saturation than standard methods. To summarize, even though NIV remains useful in unstable patients, especially in decreasing desaturation episodes, HFNC could represent a reasonable alternative in case of poor tolerance, allowing continuous oxygenation of patients requiring digestive endoscopy or trans-esophageal ultrasound.

High-flow nasal cannula therapy with sequential noninvasive ventilation versus noninvasive ventilation alone as the initial ventilatory strategy in acute COPD exacerbations: study protocol for a randomized controlled trial

BACKGROUND

Noninvasive ventilation (NIV) is the recommended mode of ventilation used in acute respiratory failure secondary to an acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Recent data has shown that high-flow nasal cannula (HFNC) treatment can be an alternative for patients with hypercapnic respiratory failure. The purpose of this study is to evaluate HFNC with sequential NIV versus NIV alone as the initial ventilatory strategy in AECOPD.

METHODS

This investigator-initiated, unblinded, single center, randomized controlled trial will be conducted in the emergency department, emergency intensive care unit, or respiratory intensive care unit of a tertiary-care urban teaching hospital. A total of 66 patients will be enrolled and randomized into the intervention group (HFNC with sequential NIV) or the control group (NIV group). The primary endpoint will be the mean difference in PaCO2 from baseline to 24 h after randomization. Secondary endpoints include the mean difference in PaCO2 from baseline to 6, 12, and 18 h, as well as the dyspnea score, overall discomfort score, rate of treatment failure, respiratory rate, rate of endotracheal intubation, length of hospital stay, and mortality.

DISCUSSION

Taking the advantages of both HFNC and NIV on AECOPD patients into account, we designed this clinical trial to investigate the combination of these ventilatory strategies. This trial will help us understand how HFNC with sequential NIV compares to NIV alone in treating AECOPD patients.

TRIAL REGISTRATION

ChiCTR2100054809.

Factors and Outcomes Associated with Failed Noninvasive Positive Pressure Ventilation in Patients with Acute Respiratory Failure

Background

The decision guild for non-invasive positive pressure ventilation (NPPV) application in acute respiratory failure (ARF) patients still needs to work out.

Methods

Adult patients with acute hypoxemic or hypercapnic respiratory failure were recruited and treated with NPPV or primary invasive mechanical ventilation (IMV). Patients’ characteristic and clinical outcomes were recorded. Logistic regression models were used to estimate the adjusted odds ratio (aOR) and 95% confidence intervals for baseline characteristics and clinical outcomes. Subgroup analyses by reason behind successful NPPV were conducted to ascertain if any difference could influence the outcome.

Results

A total of 4525 ARF patients were recruited in our facility between year 2015 and 2017. After exclusion, 844 IMV patients, 66 patients with failed NPPV, and 74 patients with successful NPPV were enrolled. Statistical analysis showed APACHE II score (aOR = 0.93), time between admission and start NPPV (aOR = 0.92), and P/F ratio (aOR = 1.04) were associated with successful NPPV. When comparing with IMV patients, failed NPPV patients displayed a significantly lower APACHE II score, higher Glasgow Coma Scale, longer length of stay in hospital, longer duration of invasive ventilation, RCW/Home ventilator, and some comorbidities.

Conclusion

APACHE II score, time between admission and start NPPV, and PaO2 can be predictors for successful NPPV. The decision of NPPV application is critical as ARF patients with failed NPPV have various worse outcomes than patients receiving primary IMV.

Comparing effectiveness of intelligent volume-assured pressure support (iVAPS) vs bi-level positive airway pressure spontaneous/timed (BPAP S/T) for hypercapnic respiratory failure in chronic obstructive pulmonary disease

BACKGROUND AND AIM

Intelligent volume-assured pressure support (iVAPS) is a relatively new hybrid mode of non-invasive ventilation (NIV). There is still limited evidence for iVAPS. The aim of this study was to compare the effectiveness of iVAPS to that of bi-level positive airway pressure spontaneous/timed (BPAP S/T) in patients with acute hypercapnic respiratory failure or acute-on-chronic hypercapnic respiratory failure caused by acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in the emergency department.

MATERIAL AND METHODS

This was an observational, retrospective study. Eighty-two patients with hypercapnic respiratory failure caused by AECOPD, who were admitted to our emergency department, were analysed. Arterial blood gas (ABG) parameters, length of hospital stay and rate of intensive care unit (ICU) admission were compared between iVAPS and BPAP S/T.

RESULTS

A total of 82 patients (26 females, 56 males, mean age 68.26 ± 11.63 years) who were treated with iVAPS (N = 26) or BPAP S/T (N = 56) were enrolled. There were no significant differences between two modes with respect to demographics such as age, gender, presence of comorbidity, usage of long-term oxygen therapy or NIV, and the baseline ABG parameters. The presence of pneumonia was significantly higher in BPAP S/T (P = .01). The rate of ICU admission was 26.9% in iVAPS vs 25% in BPAP S/T. The mean length of hospital stay was 11.5 ± 12.3 days in iVAPS and 9.7 ± 7.4 days in BPAP S/T (P = .53). The mean values of ABG parameters at the 1st and 24th hours of NIV therapy did not differ in both groups.

CONCLUSION

Both modes were similarly effective in the management of appropriately selected patients with hypercapnic respiratory failure caused by AECOPD. Hence, we underline that NIV mode selection in the emergency department should be performed in line with experiences of clinicians/institutions and accessibility of ventilator devices/modes.

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.