What is the next best step?

Transcription

1 Noninvasive Ventilation William Janssen, M.D. Assistant Professor of Medicine National Jewish Health University of Colorado Denver Health Sciences Center What is the next best step? 65 year old female with COPD. Brought to ED by family. Minimally responsive. Head CT and tox screen negative. CXR shows RLL infiltrate. Poor air movement. PaCO 2 = 95. SaO2 92% on 8L A. Rapid sequence intubation B. CPAP (8cm H 2 0 pressure) C. Bilevel (IPAP 10, EPAP 5) Continuous positive airway pressure (CPAP) Bi-level (BIPAP) Ventilatory assistance with controlled FIO 2 through a tight fitting mask (nasal or face) Most effective with alert, oriented and cooperative patient Successful in hypoxemic and hypercapnic failure (CHF and COPD exacerbations)

2 Contraindications Decreased level of consciousness Poor airway protective reflexes Copious secretions Upper gastrointestinal hemorrhage Cardiovascular instability Progressive pulmonary decompensation Facial surgery or deformity Advantages over ETT Noninvasive Easy to implement Easy to remove Allows intermittent application Improved patient comfort Reduces the need for sedation Preserves speech, swallowing, and cough Advantages vs ETT Avoids the resistive work imposed by the endotracheal tube Avoids the complications of endotracheal intubation Early (local trauma, aspiration) Late (injury to the the hypopharynx, larynx, and trachea, nosocomial infections)

3 Disadvantages System Slower correction of gas exchange abnormalities Increased initial time commitment Gastric distension (occurs in <2% patients) Mask Air leakage Eye irritation Facial skin necrosis most common complication Lack of airway access and protection Suctioning of secretions aspiration Goals of Care Decrease work of breathing Improve oxygenation (PaO 2 ) Improve ventilation (PaCO 2 ) Interfaces Partial face mask Nasal mask Full face mask

4 Modes of Ventilation Point of Reference - spontaneous respiration Pressure Modes of Ventilation CPAP Pressure No machine-assisted breaths provided Patient regulates respiratory rate and tidal volume Modes of Ventilation CPAP Improves oxygenation Can improve atelectasis Great for CHF - pushes fluid out of the alveolus Reduces the need for intubation May reduce mortality (10% vs 16% for control) Start with CPAP 6-8 mmhg, FiO2 100% Titrate to patient comfort and oxygen saturation Gray et al. N Engl J Med 2008; 359:142

5 Modes of Ventilation Bilevel Biphasic pressure support Inspiratory pressure (IPAP) during inhalation Expiratory pressure (EPAP) during exhalation Flow triggered IPAP EPAP 0 Modes of Ventilation Bilevel - Setting up the machine Start with low pressures to allow patient to adjust to the machine IPAP 8 cm H 2 O EPAP 4 cm H 2 O FiO2 100% Titrate IPAP and EPAP upward incrementally Goal is to reduce work of breathing and improve O 2, CO 2 Bedside assessment is most important Time intensive. Requires mins at the bedside Can dial in backup respiratory rate and minute ventilation COPD Exacerbations Highest quality data comes from pts that have hypercapnic respiratory failure decreases: Mortality (11% vs 21% for standard care) Intubation rate (16% vs 33%) Can be given as a brief trial for patients with CO 2 narcosis Bilevel preferred over CPAP Adjust EPAP to minimize air trapping

6 Cardiogenic Pulmonary Edema Best data are with CPAP (vs Bilevel) and in patients with co-existing hypercarbia Clear reduction in rates of intubation, hospital LOS May reduce mortality Contraindicated for patients with cardiogenic shock, acute MI Brief trial is generally sufficient (will know if it is going to work in under 10 minutes) Hypoxemic Respiratory Failure Data are mixed. Failure rates > 60% Worth a try if there is a quickly reversible cause Secretions often a problem in patients that have pneumonia No high quality studies Consider a short trial Asthma Exacerbations Will know in mins whether it is going to work Bedside assessment trumps the ABG.

7 Immunocompromised Patients Data support the use of Decreased mortality, intubation rates, ICU length of stay Putative mechanism is reduced rates of secondary infection (i.e. VAP) Key Concepts Non-invasive ventilation (NIV) should be tried as firstline therapy for acute respiratory failure due to cardiogenic pulmonary edema and acute exacerbations of COPD A brief trial of NIV should be considered to treat asthma exacerbations, acute respiratory failure, and hypercapnia with obtundation. Goals of NIV include decreased work of breathing, correction of hypoxemia, improved ventilation. Key Concepts NIV is contraindicated in patients with hemodynamic instability, an unstable airway, or high risk for aspiration Clinical assessment at the bedside is the best indicator of success Trust your instincts. If the patient is getting worse don t miss the opportunity for a controlled intubation.

8 What is the next best step? 65 year old female with COPD. Brought to ED by family. Minimally responsive. Head CT and tox screen negative. CXR shows RLL infiltrate. Poor air movement. PaCO 2 = 95. SaO2 92% on 8L A. Rapid sequence intubation B. CPAP (8cm H 2 0 pressure) C. Bilevel (IPAP 10, EPAP 5)