AB055. Long term NIV

Abstract: During the last decades, non-invasive mechanical ventilation has evolved into one of the most evidence-based areas of respiratory medicine, with many indications in acute or chronic respiratory failure. From the first application of negative pressure models during poliomyelitis epidemics to the new sophisticated positive pressure models, and the development of the “intelligent ventilators”, there has been a long time course. Undoubtedly the spur was given by better understanding of respiratory physiology during sleep and the shift of healthcare towards a chronic base. Novel randomized controlled trials (RCTs) established the use of NIV in acute respiratory failure due to exacerbations of COPD, as well as acute pulmonary edema and weaning from invasive mechanical ventilation. Long-term NIV has been used in neuromuscular diseases for many decades, first in Duchenne muscular dystrophy, and then spreading to other disorders of this category, increasing survival in inherited neuromuscular diseases. NIV should be initiated early in the course of the disease, when symptomatic nocturnal hypoventilation is detected. Combined with cough augmentation (physiotherapy, insufflation-exsufflation devices) and percutaneous gastrostomy feeding, it can delay tracheostomy and invasive ventilation. In ALS patients NIV improves the quality of life and increases survival, especially when there is no bulbar involvement. The right time to initiate ventilation in this group of patients is not well established since it is difficult to detect signs and symptom of respiratory impairment. Patients seem to benefit from an early application of NIV, and their personal decisions should always be considered before any intervention. In patients with chest wall disorders NIV—despite the fact that RCTs are lacking—has proved its value in many uncontrolled trials and numerous reports. It seems to improve the work of breathing, sleep architecture, nocturnal and daytime arterial blood gases. The role of long term NIV remains controversial in patients with chronic hypercapnic respiratory failure attributed to COPD. This happens because RCTs haven’t been able to prove benefits in survival, although the settings used in those trials seem to be insufficient to correct hypercapnia. According to more recent data higher pressure (high-intensity NIV) with the goal of achieving normocapnia can improve exercise tolerance, quality of life and survival. Obesity hypoventilation syndrome on the other hand is gradually receiving clinical interest and is recognized as a significant cause of morbidity and mortality, with a beneficial role of NIV in improving survival, hospitalizations and health related quality of life, thus reducing healthcare cost. Despite the improved awareness of the medical world dealing with the obesity epidemic, the syndrome is still under-diagnosed. Any medical specialty should perceive the value of controlling those patients in order to offer the optimal type of mechanical ventilation, depending on the underlying type of the respiratory disorder (obstructive episodes or pure hypoventilation). Patients with congestive heart failure can suffer from central sleep apnoea, OSA and Cheyne-Stokes respiration with a negative impact in their clinical outcome. CPAP therapy is indicated in resolving obstructive apnea, but is ineffective in case of central sleep apnea or Cheyne-Stokes breathing. The initial enthusiasm for assisted servo ventilation (ASV) use in this group of patients was not confirmed by a multicentre RCT (which showed increased mortality) and this type of ventilation is no longer recommended in heart failure patients with CSA and ejection fraction <45%. Scarce data exist regarding long-term NIV in patients with Cystic Fibrosis, bronchiectasis and interstitial lung diseases .It seems though that with careful patient selection NIV can play an important role in the management of those patients, even serving as a bridge to transplantation. Indications for NIV are constantly growing during the past years—apart from the above mentioned diseases- to include pediatrics and palliative care. Long-term NIV is an established first-line choice for chronic hypercapnic respiratory failure. Successful NIV application requires careful patient selection, as well as optimal ventilator settings for the best possible compliance and acceptance, with modern technology facilitating the widespread use of NIV.

Keywords: Acute; chronic respiratory failure; non-invasive mechanical ventilation