Noninvasive Mechanical Ventilation in Children ศ.พญ.อร ณวรรณ พฤทธ พ นธ หน วยโรคระบบหายใจเด ก ภาคว ชาก มารเวชศาสตร คณะแพทยศาสตร โรงพยาบาลรามาธ บด

Noninvasive Mechanical Ventilation in Children ศ.พญ.อร ณวรรณ พฤทธ พ นธ หน วยโรคระบบหายใจเด ก ภาคว ชาก มารเวชศาสตร คณะแพทยศาสตร โรงพยาบาลรามาธ บด

Noninvasive Mechanical Ventilation Provide support without artificial airways Negative-pressure ventilation Iron lung used in 1950s during polio epidemic

Iron lung Useful in neuromuscular dz, chest wall deformity, central hypoventilation Not useful in acute resp. failure Poor patients acceptance Awkward size Create upper airway obstruction

Noninvasive Mechanical Ventilation Use of mask or nasal prongs Provide support through nose and/or mouth Absence of artificial airways eg ETT, trach

Advantages Avoid intubation and/or tracheostomy Prevent injury to vocal cords Decreased risk of nosocomial pneumonia Decreased sedation requirement Preserve swallowing, feeding, speech Ambulate more easily Can be used at home

Limitations Nasal-mask (interface) intolerance Discomfort Asynchrony Serious air leaks Gastric distension Eye irritation, conjunctivitis Epistaxis, nasal irritation, rhinorrhea, dry nose&throat Facial skin breakdown or necrosis esp. at the nose bridge

Limitations Nasal-mask (interface) intolerance Discomfort Asynchrony Serious air leaks Gastric distension Eye irritation, conjunctivitis Epistaxis, nasal irritation, rhinorrhea, dry nose&throat Facial skin breakdown or necrosis esp. at the nose bridge -- Abnormal facial growth esp. in pre-pubertal children

Selecting patients for noninvasive ventilation Inclusion criteria Acute or chronic respiratory failure Sleep-related breathing disorder Upper airway obstruction Relative contraindication Inability to use nasal or face mask High risk of aspiration Life threatening refractory hypoxemia Require ETT for secretion drainage Hemodynamic instability

Acute Hypoxemic Respiratory Noninvasive Failure Invasive Antonelli. N Engl J Med 1998:339:429-435

Obstructive sleep apnea

CPAP Pneumatic splint to prevent airway collapse Increased end expiratory lung volume Lethal risk are essentially non-existence

Intermittent noninvasive ventilation Only 4-64 6 hours per night can improve Daytime gas exchange and dyspnea May be explained by Rest fatigued resp. muscles Improve muscle function Re-expand microatelectasis Improve lung compliance Prevent blunting hypercapnic drive

Central hypoventilation syndrome

Kyphoscoliosis

Nasal masks

Chin strap

Full face mask (rarely used)

Nasal cannula

Head gear

Modes of noninvasive positive pressure ventilation Continuous positive airway pressure (CPAP) Bilevel positive airway pressure (BiPAP) ICU ventilators Pressure support Pressure control Volume controlled

CPAP vs. BiPAP CPAP work as upper airway splint BiPAP increase ventilation + upper airway splint

BiPAP vs. ICU ventilators As responsive As able to meet ventilatory demand Better able to compensate for leaks Transition to exhalation as well

BiPAP Lack of monitoring Lack of alarms CO 2 rebreathing due to single inspirationexpiration circuit FiO 2 accuracy/consistency??

ICU ventilators for NIV Few compensate for leaks???? Nasal / some orofacial masks may be a problem Cycling to exhalation a problem Most alarms not designed for NIV Do monitor patient / ventilator system Do alarm problem situations Do provide precise FiO 2

Ideally BiPAP for use in ICU Able to monitor the patient / ventilator system (pressure, flow, and volume waveforms) Appropriately alarmed Able to provide accurate, high FiO 2 Designed for use in the ICU

Humidification High flows result in dried retained secretions Use heated (pass over) humidifier Adjust to patient comfort