Current Status of Noninvasive Ventilation Use in Korean Intensive Care Units: A Prospective Multicenter Observational Study

Treatment of acute respiratory failure: noninvasive mechanical ventilation

Background: Noninvasive ventilation (NIV) has been an important strategy to support patients with respiratory failure, while preventing complications assorted with invasive mechanical ventilation. Physicians need to be aware of the various roles of NIV and the challenges encountered in clinical practice.Current Concepts: Traditionally, the application of NIV has been well-known to be associated with reduced mortality in patients with chronic obstructive pulmonary disease (COPD) or acute pulmonary edema and those suffering from acute respiratory failure. However, despite some positive results of NIV treatment in patients with de novo hypoxemic respiratory failure such as acute pneumonia or acute respiratory distress syndrome, NIV failure (or delayed intubation) can have deleterious effects on patients outcomes. Besides, the aggravation of lung injury should also be taken into consideration when applied to patients exhibiting high respiratory drive. Nonetheless, NIV has potential for wide applications in various clinical situations such as facilitation of ventilator weaning, post-operative respiratory failure, or palliative treatment.Discussion and Conclusion: In addition to the strong evidence in patients with acute respiratory failure due to COPD or acute pulmonary edema, the NIV treatment can be potentially used for various clinical conditions. However, compared to European countries, the prevalence of NIV use continues to remain lower in South Korea. Nevertheless, when applied in appropriately selected patients in a timely manner, NIV treatment can be associated with improved patient outcomes.

Current status of treatment of acute respiratory failure in Korea

Background: Acute respiratory failure (ARF) is one of the most common causes of intensive care unit (ICU) admission and in-hospital mortality. In South Korea, about 25% of patients admitted to the ICU require mechanical ventilation. The in-hospital mortality rate of these patients is 48%. Respiratory failure can be categorized based on pathophysiologic derangements, and the treatment options vary depending on their classification. This study discusses the status and treatment strategies of patients with ARF in Korea.Current Concepts: The most common treatment for ARF was conventional oxygen therapy, being used at least once in 7.0% of all admitted adult patients and 85.1% of patients admitted with respiratory failure. High-flow oxygen therapy was required in 1.4% of all admissions and 17.2% of respiratory failure-related admissions. High-flow oxygen therapy was attempted in 19.1% of patients who needed invasive mechanical ventilation. Non-invasive positive pressure ventilation (NIV) was used in 0.4% of all admissions and 5.1% of respiratory failure-related admissions. Hypercapnic respiratory failure (57.1%) was the most common reason for NIV use. Invasive mechanical ventilation was required in 2.8% of all admissions and 33.8% of respiratory failure-related admissions.Discussion and Conclusion: Despite its clinical significance, no large-scale studies have been performed on the etiology, treatment, and prognosis of patients with ARF in South Korea. A multicenter or a Korean National Health Insurance Service database study is necessary to accurately identify the characteristics, diagnose problems, and develop treatment guidelines for patients with ARF in South Korea.

Utilization of pain and sedation therapy on noninvasive mechanical ventilation in Korean intensive care units: a multi-center prospective observational study

Background

The use of sedative drugs may be an important therapeutic intervention during noninvasive ventilation (NIV) in intensive care units (ICUs). The purpose of this study was to assess the current application of analgosedation in NIV and its impact on clinical outcomes in Korean ICUs.

Methods

Twenty Korean ICUs participated in the study, and data was collected on NIV use during the period between June 2017 and February 2018. Demographic data from all adult patients, NIV clinical parameters, and hospital mortality were included.

Results

A total of 155 patients treated with NIV in the ICUs were included, of whom 26 received pain and sedation therapy (sedation group) and 129 did not (control group). The primary cause of ICU admission was due to acute exacerbation of obstructed lung disease (45.7%) in the control group and pneumonia treatment (53.8%) in the sedation group. In addition, causes of NIV application included acute hypercapnic respiratory failure in the control group (62.8%) and post-extubation respiratory failure in the sedation group (57.7%). Arterial partial pressure of carbon dioxide (PaCO₂) levels before and after 2 hours of NIV treatment were significantly decreased in both groups: from 61.9±23.8 mm Hg to 54.9±17.6 mm Hg in the control group (P<0.001) and from 54.9±15.1 mm Hg to 51.1±15.1 mm Hg in the sedation group (P=0.048). No significant differences were observed in the success rate of NIV weaning, complications, length of ICU stay, ICU survival rate, or hospital survival rate between the groups.

Conclusions

In NIV patients, analgosedation therapy may have no harmful effects on complications, NIV weaning success, and mortality compared to the control group. Therefore, sedation during NIV may not be unsafe and can be used in patients for pain control when indicated.

Non-invasive ventilation for acute respiratory failure: pressure support ventilation vs. pressure-controlled ventilation

Background

The best ventilator mode for patients receiving non-invasive ventilation (NIV) has not been clarified. This study compared the effectiveness of two pressure-targeted modes, i.e., pressure support ventilation (PSV) and pressure-controlled ventilation (PCV), in patients receiving NIV.

Methods

This was a prospective multicentre observational study of NIV use for acute respiratory failure (ARF) in adult patients. We compared the two pressure-targeted modes in terms of NIV success and complication rates.

Results

Among 176 patients receiving NIV, 88 patients were included in the study (PCV mode, n=29; PSV mode, n=59). The study population had a median age of 73.0 years and median body mass index of 20.8 kg/m². The applied inspiratory positive airway pressure (IPAP) was higher in patients with PCV than in those with PSV [18.0 cmH₂O (15.0–20.5 cmH₂O) vs. 15.0 cmH₂O (12.0–17.0 cmH₂O), respectively, P=0.001]. More patients with PCV received sedatives and experienced dry mouth than those with PSV; however, the incidences of large leaks were low in both groups (n=5 vs. n=2, respectively). With regard to NIV outcomes, 24 (27.2%) patients experienced NIV failure and 13 (14.8%) died in hospital. PSV mode was a significant factor for NIV success [odds ratio (OR), 2.303; 95% confidence interval (CI), 1.216 to 4.360] in multivariate analyses and this association remained significant in a 1:1 matched cohort (n=29 per group).

Conclusions

In contrast to PCV mode, PSV mode was significantly associated with NIV success in the intensive care unit setting, particularly when large leaks were not a major concern. Nevertheless, further well-designed multicenter, protocol-driven randomized controlled trials are warranted.