© Springer International Publishing Switzerland 2016
Antonio M. Esquinas (ed.)Noninvasive Mechanical Ventilation10.1007/978-3-319-21653-9_3737. Acute Applications of Noninvasive Ventilation in Obesity Hypoventilation Syndrome: Evidence and Key Practical Recommendations
(1)
Department of Respiratory and Critical Care Medicine, Schaffner Hospital, Lens, France
37.1 Introduction
37.2 Discussion
37.2.1 Main Indications for NIV
37.2.3 Ventilator Settings
37.3 Conclusion
Keywords
ObesityAcute respiratory failureNoninvasive ventilationObesity hypoventilation syndromeAbbreviations
ARF
Acute respiratory failure
BMI
Body mass index
EPAP
Expiratory positive airway pressure
IPAP
Inspiratory positive airway pressure
NIV
Noninvasive ventilation
OHS
Obesity hypoventilation syndrome
OSAS
Obstructive sleep apnea syndrome
37.1 Introduction
Obesity hypoventilation syndrome (OHS) refers to the form of chronic respiratory failure specifically resulting from obesity. The diagnostic criteria include obesity (body mass index (BMI) > 30 kg/m2), alveolar hypoventilation (PaCO2 > 45 mmHg), and sleep-disordered breathing, without any common cause of respiratory failure (e.g., chronic obstructive pulmonary disease (COPD), chest wall deformity, or neuromuscular disease) [1]. Given the current epidemic of obesity, OHS is expected to become the second leading cause of chronic respiratory failure worldwide [2, 3]. The higher the BMI, the higher the incidence of OHS [2]. The diagnosis is usually made during an episode of acute respiratory failure (ARF), which is the most common life-threatening complication of OHS. Over the last two decades, noninvasive ventilation (NIV) has emerged as the most effective treatment for ARF in obese patients [1].
37.2 Discussion
37.2.1 Main Indications for NIV
37.2.1.1 Type 2 (Hypercapnic) Respiratory Failure
Hypercapnic ARF is the most meaningful indication for NIV especially in morbidly obese patients. During a 13-year study period, Carillo et al. [4] have prospectively evaluated the benefit of NIV in 173 patients with OHS versus 543 patients with COPD in hypercapnic ARF. NIV was more effective in preventing intubation in decompensated OHS than in COPD (NIV failure 7 % vs 13 %, p = 0.037), resulting in a lower in-hospital mortality in the OHS group compared with COPD patients (6 % vs 18 %, p < 0.001). In our prospective study including 76 morbidly obese patients weakened by malignant OHS and admitted to the intensive care unit (ICU) for ARF, NIV was constantly successful in patients with idiopathic hypercapnic ARF [5]. The severity of respiratory acidosis, the level of hypercapnia, and the depth of encephalopathy were not reliable criteria for predicting NIV failure. Along the same lines, Dias et al. [6] clearly demonstrated that NIV is safe and successful in reversing hypercapnic coma in patients in acute-on-chronic respiratory failure. In this series, the success rate reached 80 % in comatose patients (Glasgow Coma Score <7, n = 95) as compared with 70 % in non-comatose patients (Glasgow Coma Score >8, n = 863, p = 0.04). Response to NIV may be delayed, especially in hypercapnic obese patients on respiratory depressant drugs or diuretics promoting alveolar hypoventilation [5].
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
