Non-invasive negative and positive pressure ventilation in the treatment of acute on chronic respiratory failure

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

Prospective Comparative Evaluation of Noninvasive and Invasive Mechanical Ventilation in Patients of Chronic Obstructive Pulmonary Disease with Acute Respiratory Failure Type II

INTRODUCTION

Acute respiratory failure is a potential complication of chronic obstructive pulmonary disease (COPD) that severely affects the health of the patient and may require mechanical ventilation. We compared noninvasive and invasive mechanical ventilation in COPD patients with acute respiratory failure type II to validate clinical outcome based on biochemical analysis of arterial blood gases (ABGs) and pulmonary parameters in terms of duration of mechanical ventilation, period spent in intensive care unit (ICU) and mortality.

MATERIALS AND METHODS

After approval of institutional ethical committee 100 patients were selected for randomized prospective controlled trial and divided into two groups of 50 each according to mode of mechanical ventilation. Group-I patients managed with noninvasive ventilation (NIV) Group-ll managed with invasive ventilation.

RESULTS

Demographic data between two groups were comparable. ABG parameters were better at 2 h and 6 h interval in NIV as compared to invasive ventilation (P < 0.05). The duration of ventilation and total time spent in ICU was 106±10 hours and 168±8 hours respectively in NIV group and 218 ± 12 and 280 ± 20 in invasive group. On intergroup comparison these were significantly less in noninvasive group (P < 0.05). Hospital acquired pneumonia occurred in 10% of patients in invasive group whereas no incidence of pneumonia found in noninvasive group. Mortality rate was 12% in invasive groups and 2% in noninvasive groups.

CONCLUSION

NIV leads to significant improvement in ABG and pulmonary parameters and it reduces duration of ventilation and total period of hospital stay so it can be used as an alternative to invasive ventilation as first-line treatment in COPD.

Continuous positive airway pressure (CPAP) provision with a pediatric helmet for treatment of hypoxemic acute respiratory failure in dogs

OBJECTIVE

To evaluate arterial blood gas parameters and pulmonary radiography, before and after provision of continuous positive airway pressure (CPAP) via a pediatric helmet in dogs with acute hypoxemic respiratory failure.

DESIGN

Single-center, observational study conducted from 2016 to 2017.

SETTING

University teaching hospital.

ANIMALS

Seventeen dogs presenting with clinical signs compatible with respiratory failure, confirmed by arterial blood gas analyses.

INTERVENTIONS

For each animal arterial blood samples and thoracic radiographs were performed at arrival (T₀ ). Hypoxemic dogs (PaO₂  <80 mm Hg), without evidence of pneumothorax or pleural effusion, received CPAP ventilation via a pediatric Helmet for at least 1 hour. At the end of CPAP ventilation, a second arterial blood gas analysis was performed at room air (T₁ ). The F-shunt was also calculated.

MEASUREMENT AND MAIN RESULTS

Respiratory rate, heart rate and rhythm, mean blood pressure, mucosal membrane color, and rectal temperature were recorded. Tolerance to the helmet was evaluated using a predetermined scoring system. Two dogs were excluded from the study for low tolerance to the helmet. In 15 of 17 dogs, a significant difference between T₀ and T₁ was noted for PaO₂ (60.84 ± 3 mm Hg vs 80.2 ± 5.5 mm Hg), P(A-a)O₂ (52.4 ± 4.4 mm Hg vs 35.2 ± 6 mm Hg), PaO₂ /FiO₂ (289.7 ± 14.3 vs 371 ± 21), and %SO₂ (91.3 vs 98.8). In 15 of 17 dogs, the helmet was well tolerated. F-shunt significantly decreased following provision of CPAP (37%; range, 8.4-68% vs 6%; range, -5.6-64.3%).

CONCLUSION

The use of a pediatric helmet appears to be a suitable device for delivery of CPAP in dogs with hypoxemic acute respiratory failure. The device appears to be reasonably tolerated and improved oxygenation in most dogs.

Intensive care units in Turkish hospitals: do they meet the minimum standards?

BACKGROUND

International and national standards for ICUs have been developed to ensure patient safety and provide effective and efficient service in these units. However, global economic crises along with shortages in professional health care staff affect the ability of ICUs to meet and maintain these standards.

AIMS AND OBJECTIVES

The aim of this study was to ascertain whether the equipment and workforce in intensive care units (ICUs) in Turkish hospitals meet current ICU standards.

DESIGN

This is a descriptive study based on the results of a survey questionnaire.

METHODS

In total, 145 ICUs in university and private hospitals in Turkey participated in this survey. Data collection was done by means of a survey questionnaire that assessed the current equipment and workforce in these ICUs.

RESULTS

We found that 97·0% of the occupied beds in the ICUs had a cardiac monitor. Crash-carts were present in every ICU. Transport monitors and transport ventilators were available in two of three and in one of two ICUs, respectively. In 82·8% of the ICUs, a physician (as a trainee level) was present at all times, while only a few ICUs had ICU-care team members such as respiratory- and physiotherapist, clinical pharmacists and dieticians available. There was a general shortage of nursing staff in ICUs.

CONCLUSION

Currently, ICUs in Turkish hospitals meet the majority of standards for ICU equipment, but they fail to meet both the international and national standards for ICU workforce requirement.

CLINICAL RELEVANCE

Hospital and ICU managers could use our findings to compare their facilities with others or to identify areas in need of improvement.

Respiratory High-Dependency Care Units for the burden of acute respiratory failure

The burden of acute respiratory failure (ARF) has become one of the greatest epidemiological challenges for the modern health systems. Consistently, the imbalance between the increasing prevalence of acutely de-compensated respiratory diseases and the shortage of high-daily cost ICU beds has stimulated new health cost-effective solutions. Respiratory High-Dependency Care Units (RHDCU) provide a specialised environment for patients who require an "intermediate" level of care between the ICU and the ward, where non-invasive monitoring and assisted ventilation techniques are preferentially applied. Since they are dedicated to the management of "mono-organ" decompensations, treatment of ARF patients in RHDCU avoids the dangerous "under-assistance" in the ward and unnecessary "over-assistance" in ICU. RHDCUs provide a specialised quality of care for ARF with health resources optimisation and their spread throughout health systems has been driven by their high-level of expertise in non-invasive ventilation (NIV), weaning from invasive ventilation, tracheostomy care, and discharging planning for ventilator-dependent patients.

Hypercapnic encephalopathy syndrome: a new frontier for non-invasive ventilation?

According to the classical international guidelines, non-invasive ventilation is contraindicated in hypercapnic encephalopathy syndrome (HES) due to the poor compliance to ventilatory treatment of confused/agitated patients and the risk of aspirative pneumonia related to lack of airways protection. As a matter of fact, conventional mechanical ventilation has been recommended as "golden standard" in these patients. However, up to now there are not controlled data that have demonstrated in HES the advantage of conventional mechanical ventilation vs non-invasive ventilation. In fact, patients with altered mental status have been systematically excluded from the randomised and controlled trials performed with non-invasive ventilation in hypercapnic acute respiratory failure. Recent studies have clearly demonstrated that an initial cautious NPPV trial in selected HES patients may be attempt as long as there are no other contraindications and the technique is provided by experienced caregivers in a closely monitored setting where ETI is always readily available. The purpose of this review is to report the physiologic rationale, the clinical feasibility and the still open questions about the careful use of non-invasive ventilation in HES as first-line ventilatory strategy in place of conventional mechanical ventilation via endotracheal intubation.

COPD exacerbation: mortality prognosis factors in a respiratory care unit

OBJECTIVE

The aim of our study was to investigate the mortality predictive factors after a severe exacerbations of COPD admitted to a Spanish respiratory intermediate care unit (IRCU).

PATIENTS AND METHODS

Prospective observational 2 years study, where we included all episodes of acute exacerbations of COPD with hypercapnic respiratory failure admitted in an IRCU. We analyzed different sociodemographic, functional and clinical variables including physical activity.

RESULTS

We collected data from 102 consecutive episodes admitted to IRCU (90.1% men). Mean age was 69.4±10.6. The mean APACHE II was 19.6±5.0 and 9.5% presented a failure of other non respiratory organ. Non invasive ventilation was applied in 75.3% of the episodes and this treatment failed in 11.6% of them. The duration of stay in the IRCU was 3.5±2.1 days and 8.0±5.3 days in the hospital. The hospital mortality rate was 6.9%, and another 12.7% after 90 days of discharged. In order to predict hospital mortality, multivariant statistics identified a model with AUC of 0.867, based in 3 variables: the number of previous year admission for COPD exacerbation (p=0,048), the respiratory rate after 2 hours of treatment in the IRCU (p=0.0484) and the severity of the disease established with ADO score (p=0.0241).

CONCLUSIONS

The number of previous year admission for COPD exacerbation, the severity of the disease established with ADO score, the respiratory rate after 2 hours of treatment, allow us to identify what patients with a COPD exacerbation admitted in a IRCU can die during this episode.

[Non-invasive ventilation as treatment for acute respiratory insufficiency. Essentials from the new S3 guidelines]

BACKGROUND

Scientific evidence is accumulating that non-invasive ventilation (NIV) may be beneficial for different patient groups with acute respiratory insufficiency (ARI). The aim of the new S3 guidelines is to propagate evidence-based knowledge about the indications and limitations of NIV in clinical practice.

METHODS

A total of 28 experts from 12 German medical societies were involved in the process of development of the present guidelines. These experts systematically analyzed approximately 2,900 publications. Finally, the recommendations were discussed and approved in two consensus conferences.

RESULTS

In hypercapnic ARI, NIV reduces the length of stay and mortality during intensive care treatment [grade A recommendation (A)]. Patients with cardiopulmonary edema should be treated with continuous positive airway pressure (CPAP) or NIV (A). For immunocompromized patients with ARI, NIV reduces the mortality (A). In patients with postextubation respiratory failure and during weaning from mechanical ventilation, NIV reduces the risk of reintubation (A). For patients who decline to be ventilated invasively, NIV may be an acceptable alternative (B). Non-invasive ventilation can also successfully be used in pediatric patients with ARI caused by different reasons (C). In acute respiratory distress syndrome (ARDS) NIV cannot generally be recommended because the failure rate is relatively high.

CONCLUSION

Non-invasive ventilation is still not as widely implemented in clinical medicine as would be expected on the basis of the scientific literature. The aim of the present guidelines is to further propagate NIV for the treatment of ARI.

Iron lung versus mask ventilation in acute exacerbation of COPD: a randomised crossover study

OBJECTIVE

To compare iron lung (ILV) versus mask ventilation (NPPV) in the treatment of COPD patients with acute on chronic respiratory failure (ACRF).

DESIGN

Randomised multicentre study.

SETTING

Respiratory intermediate intensive care units very skilled in ILV.

PATIENTS AND METHODS

A total of 141 patients met the inclusion criteria and were assigned: 70 to ILV and 71 to NPPV. To establish the failure of the technique employed as first line major and minor criteria for endotracheal intubation (EI) were used. With major criteria EI was promptly established. With at least two minor criteria patients were shifted from one technique to the other.

RESULTS

On admission, PaO(2)/FiO(2), 198 (70) and 187 (64), PaCO(2), 90.5 (14.1) and 88.7 (13.5) mmHg, and pH 7.25 (0.04) and 7.25 (0.05), were similar for ILV and NPPV groups. When used as first line, the success of ILV (87%) was significantly greater (P = 0.01) than NPPV (68%), due to the number of patients that met minor criteria for EI; after the shift of the techniques; however, the need of EI and hospital mortality was similar in both groups. The total rate of success using both techniques increased from 77.3 to 87.9% (P = 0.028).

CONCLUSIONS

The sequential use of NPPV and ILV avoided EI in a large percentage of COPD patients with ACRF; ILV was more effective than NPPV on the basis of minor criteria for EI but after the crossover the need of EI on the basis of major criteria and mortality was similar in both groups of patients.

Clinical practice guideline: non-invasive mechanical ventilation as treatment of acute respiratory failure

INTRODUCTION

Non-invasive mechanical ventilation (NIV) has been used to treat acute respiratory failure (ARF) for approximately 20 years. This guideline addresses the indications for, and limitations of, NIV as treatment for ARF according to evidence-based criteria.

METHODS

A panel of experts from 12 scientific medical societies reviewed circa 2900 publications. The panel judged the clinical relevance of these studies and assessed the evidence presented in each, then held two interdisciplinary consensus conferences to formulate guideline recommendations and algorithms.

RESULTS

Whenever possible, NIV should be preferred to invasive mechanical ventilation, in order to avoid the risk of ventilator and tube-associated complications such as nosocomial pneumonia (grade of recommendation A). Particularly in patients with hypercapnic ARF, NIV reduces the rate of hospital-acquired pneumonia, the length of hospital stay and mortality in the intensive care unit and in the hospital (grade of recommendation A). NIV (or continuous positive airway pressure) is also recommended in cardiogenic pulmonary edema (grade of recommendation A), as treatment for ARF in immunocompromised patients (grade of recommendation A), to prevent postextubation failure, to facilitate weaning in patients with hypercapnic ARF (grade of recommendation A), and to improve dyspnea in palliative care (grade of recommendation C). NIV is not generally recommended in patients with hypoxic ARF because of its high failure rate of 30% to over 50% in such patients.

DISCUSSION

Although evidence indicates that NIV can be used as the treatment of first choice for several indications, it is still underutilized in the acute setting. These guidelines provide evidence-based information about the indications for, and limitations of, NIV in the treatment of ARF.

Experiences from introducing non-invasive ventilation in the intensive care unit: a 2-year prospective consecutive cohort study

OBJECTIVE

To describe 2 years of experience and staff learning curves after the introduction of non-invasive ventilation (NIV).

METHODS

A prospective, consecutive, strictly observational, 2-year cohort study of all patients treated with NIV in a county general hospital intensive care unit (ICU), with no interventions, was performed.

RESULTS

One hundred and fifty-seven patients with 15 different diagnoses were treated with NIV. An increasing number of patients were treated in the second year and, probably as a result of increased staff experience, the NIV treatment time and overall time spent in the ICU were less in the second year of the study period (30 h vs. 19 h and 55 h vs. 34 h, respectively; P < 0.05). Patients were also intubated earlier if NIV failed during the second year. Of the 157 patients, 119 had a full treatment option (i.e. including the possibility of invasive mechanical ventilation) and 26% died; their Acute Physiology and Chronic Health Evaluation II (APACHE II)- and Simplified Acute Physiology II (SAPS II)-predicted death rates were 31% and 32% respectively (not significant, NS). The overall mortality rate in all NIV patients was 38%, compared with predicted death rates of 36% and 33%, respectively (NS). 'Do-not-intubate' orders were issued for 38 of the 157 patients, and 11 of these (29%) left the hospital alive. Patients treated successfully with NIV had significantly lower APACHE II scores than those in whom it failed (18.8 vs. 22, P= 0.01).

CONCLUSION

With increasing staff experience, more patients may be treated with NIV and the treatment period decreases significantly. Weaning from NIV has almost exclusively been taken over by nurses. Unselected cohorts of patients with chronic obstructive pulmonary disease can be treated successfully with NIV, and NIV offers a treatment option even for some patients with a 'do-not-intubate' order.

Team model: Advocating for the optimal method of care delivery in the intensive care unit

OBJECTIVE

To review published data on the team model of intensive care unit (ICU) care delivery.

DESIGN

Nonexhaustive, selective literature search.

SETTING

Review of literature published in the English language.

PATIENTS/SUBJECTS

Humans cared for in ICUs.

INTERVENTIONS

None.

RESULTS

The team model for delivery of ICU care reduces mortality, ICU length of stay, hospital length of stay, and cost of care. Convincing data suggest that merely having daily rounds led by an intensivist enhances patient care significantly. Further improvements can be obtained by maintaining a nurse-to-patient ratio of no greater than 1:2, adding critical care pharmacists, and providing dedicated respiratory therapists to the ICU team.

CONCLUSION

Current and looming shortages of all ICU healthcare providers is a barrier to universal implementation of the team model. Advocating for the ICU team model for critical care delivery requires local, regional, national, and international activities for success.