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KEEPING YOUR LUNGS HEALTHY: SMA TYPE II and III. Mary Schroth MD Pediatric Pulmonary American Family Children’s Hospital University of Wisconsin School of Medicine and Public Health. Objectives. Understand how SMA affects breathing Learn techniques to help your child’s breathing
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KEEPING YOUR LUNGS HEALTHY:SMA TYPE II and III Mary Schroth MDPediatric PulmonaryAmerican Family Children’s HospitalUniversity of Wisconsin School of Medicine and Public Health
Objectives • Understand how SMA affects breathing • Learn techniques to help your child’s breathing • Realize that you have choices in your child’s respiratory care
Encompasses: • Diagnosis • Respiratory Care • GI and Nutrition • Orthopedic Concerns • Palliative Care Wang C et al, J Child Neurol 2007; 22:1027.
Respiratory Function in SMA • Features: • Very weak intercostal muscles • Chest wall: very soft and flexible during the first year of life • Diaphragm: primary muscle used to breath
Chest Wall Changes Normal SMA
Results of Respiratory Muscle Weakness in SMA • Difficulty coughing • Small, shallow breaths during sleep • Chest wall and lung underdevelopment • Recurrent infections that contribute to muscle weakness. Wang C et al, J Child Neurol 2007; 22:1027.
SMA Pulmonary Natural History Natural History Assessment Intervention Physical examination Normal breathing Breathing and swallowing muscle weakness Pulmonary function, peak cough flow, respiratory muscle strength Airway clearance with cough assistance Dream related sleep disordered breathing Weak cough, reduced peak cough flows Chest xray, Sleep study Nocturnal non-invasive ventilation Swallow function evaluation Non-dream and dream sleep disordered breathing Swallow difficulty Chest infections Nocturnal or continuous non-invasive ventilation Daytime ventilatory failure Death Wang C et al, J Child Neurol 2007; 22:1027.
Assessment and Monitoring of Respiratory Status • Evaluate Cough Effectiveness • Direct observation • Respiratory muscle function tests • MIP, MEP, peak cough flow • Physical Exam • Respiratory rate • Work of breathing • Paradoxical breathing Wang C et al, J Child Neurol 2007; 22:1027.
Assessment and Monitoring of Respiratory Status (cont.) • For sitters and walkers • Pulmonary Function Tests • spirometry • lung volumes • Polysomnography or sleep study • to evaluate for sleep disorder breathing • Scoliosis evaluation Wang C et al, J Child Neurol 2007; 22:1027.
Chronic Management Goals • Normalize oxygen saturation and CO2 • Improve sleep • Facilitate care at home • Decrease hospitalizations and PICU stays • Decrease burden of illness on families Wang C et al, J Child Neurol 2007; 22:1027.
Based on Experience and Consensus: • Early aggressive and proactive intervention may prolong life without compromising quality of life. Wang C et al, J Child Neurol 2007; 22:1027.
Chronic Management • Recognizing changes from baseline • Airway clearance • Assisted Cough • Secretion mobilization • Respiratory support Wang C et al, J Child Neurol 2007; 22:1027.
Assisted Cough • Manual cough assist • In-exsufflator cough machine or Cough Assist
Mechanical In-Exsufflation • In-exsufflator cough machine improved cough expiratory flow rates • Mean peak expiratory flow rates of 21 patients with NMD • Unassisted 1.81 ± 1.03 L/sec • Assisted cough 4.27 ± 1.29 L/sec • Exsufflator 7.47 ± 1.02 L/sec • Normal PCF 6-12 L/sec • Critical PCF is 2.7 L/sec Bach J Chest 1993; 104:1553.
Cough Assist Device • SETTINGS to use by mask, mouth piece, tracheostomy tube or endotracheal tube. • INHALE • Start at +30, increase to +40 cm H2O for 1 sec. • EXHALE • Start at –30, increase to -40 cm H2O for 1 sec. • PAUSE TIME • 1-2 sec.
Cough Assist Device • Perform 4 sets of 5 breaths • rest 1-2 minutes between sets. • Ideally use manual cough assist with cough machine. • Suction upper airway ortracheostomy tube or ET tube after use. • Use as often as needed.
Chest Wall Expansion Exercise • Bagged or manual insufflations • Resuscitator bag with mask • Cough Assist device • INHALE • Start at +30, increase to +40 cm H2O for 1 sec. • EXHALE • Start at –30, increase to -40 cm H2O for 1 sec. time at 1-2 seconds • exhalation time at 0 • PAUSE time 1-2 seconds • 4 sets of 5 breaths twice per day.
Secretion Mobilization Techniques • Manual Chest Physiotherapy or Mechanical Percussion • Postural Drainage • Use pulse oximetry to guide respiratory therapy. • Do before eating or at least 30 minutes after eating. Wang C et al, J Child Neurol 2007; 22:1027.
Other Techniques Not Proven Vest Airway Clearance Intrapulmonary Percussive Ventilator (IPV)
FRC Relative to Position From Nunn’s Applied Respiratory Physiology, 2000
Pulse Oximetry • Acute decreased oximetry (< 95% while AWAKE) • suggests atelectasis or mucus plugging. • may be the first evidence of respiratory compromise. • < 95% while ASLEEP • suggests hypoventilation or mucus plugging.
Secretion Management • May improve mucociliary clearance • Albuterol nebulized • May thin secretions • Acetylcysteine (Mucomyst™) nebulized • DNase (Pulmozyme™) nebulized
Secretion Management (cont.) • Alter upper airway secretions • Medications • Glycopyrrolate (Robinul) by mouth/G-tube • Scopolamine patch • Steroid nasal spray • Antihistamines/Decongestants by mouth/G-tube • Botox injections of the salivary glands • Surgical Management • Salivary gland resection
Respiratory Support • Non-invasive ventilation • Bilevel positive airway pressure • Mechanical ventilation • Invasive ventilation • Tracheotomy Wang C et al, J Child Neurol 2007; 22:1027.
Indications for NIV • Standard: • Hypoventilation • Oxygen saturation <90%, CO2 >45 • Obstructive apnea • Post-operative care
Indications for NIV • Specific to SMA • Oxygen saturation <94% while asleep and or elevated carbon dioxide level during sleep • Needing intubation or BiPAP during a cold • Pneumonia or atelectasis • Chest wall collapse/pectus excavatum • Poor sleep quality
Chest Wall Development After NIV 6 mths 18 mths Courtesy of A. Simonds, Royal Brompton Hospital, UK
Respironics Small Child Nasal Mask with Comfort Flap and Head Gear
Respironics Profile Lite Small Child Nasal Mask and Head Gear
Non-Invasive Positive Pressure Ventilation Devices • Bilevel positive airway pressure (BiPAP) 2. Home mechanical ventilator
Bilevel Positive Airway Pressure (BiPAP) Devices • Recommend ST (spontaneous timed) devices • Provides backup respiratory rate • True respiratory muscle rest • Synchronizes with efforts
Bilevel Positive Airway Pressure (BiPAP) ST Devices • Respironics • BiPAP Synchrony – being phased out • BiPAP AVAPS – average volume assured pressure support • Guarantees tidal volume breaths within range of inspiratory pressure • Minimum tidal volume 200 ml • Smallest child approximately 20-25 kg. • BiPAP ST
Bilevel Positive Airway Pressure (BiPAP) ST Devices • ResMed • VPAP III ST • Can set breath trigger and cycle sensitivity
Bilevel Positive Airway Pressure (BiPAP) ST Devices • Example settings: • Inspiratory Positive Airway Pressure IPAP (PIP): • 14-20 cm of H20 • Expiratory Positive Airway Pressure EPAP: • 3-6 cm of H20
Bilevel Positive Airway Pressure (BiPAP) • Respiratory rate • Set to capture breathing effort and rest child • Example settings: • 1-3 years old, RR=25 • >3 years old, RR=20-25 • Teenagers to adult, RR=14-16 and recommend sleep study to titrate.
Bilevel Positive Airway Pressure (BiPAP) • Inspiratory time • Time over which the breath is delivered • Example: • Toddlers to child: 0.8 seconds • School age: 1 second • Teen age: 1-1.5 seconds depending on comfort
Bilevel Positive Airway Pressure (BiPAP) • Rise time • Determines how fast the pressure increased to the peak inspiratory pressure • Lower numbers = faster rise time
Home Mechanical Ventilator Examples: LTV 950 or 1150, LP-10, Newport HT-50 Modes: - Assist control - SIMV (Synchronized intermittent mechanical ventilation) • pressure ventilation • volume ventilation
NIPPV Disadvantages • Gastric distention and emesis especially if children are constipated • Nasal bridge discomfort and other skin irritation • Face changes
NIPPV Challenges • Swallowing difficulty • Excessive secretions • Gastroesophageal Reflux • > 16 hrs/day of ventilation
Invasive Ventilation • Tracheostomy placement • Not an acute intervention Wang C et al, J Child Neurol 2007; 22:1027.
Palliative Care • NIV can be used as palliative therapy. • Goals: • Prevent PICU stays and tracheotomy. • Provide symptom relieve • pain, dyspnea, agitation, nausea, anxiety • Provide psychological, social and spiritual support for child and family Wang C et al, J Child Neurol 2007; 22:1027.
The Last Straw for NMD Lung Function • Viral respiratory infections • Result in: • Increased muscle weakness • Increased airway secretions • More difficulty breathing • The answer is not supplemental oxygen!
Acute Care Respiratory Management • Goals: • Normalize oxygen and carbon dioxide exchange • Reduce lung collapse • Enhance airway secretion clearance Wang C et al, J Child Neurol 2007; 22:1027.
Airway Clearance • Assisted Cough • manual cough assist • mechanical cough assist machine • Suctioning mouth or airway • Chest physiotherapy • Postural drainage Wang C et al, J Child Neurol 2007; 22:1027.
University of WI Cold Care Protocol • Perform every 4 hours: • Airway clearance • 15 minutes • Cough Assist • 4 sets of 5 breaths • Postural drainage • 15 minutes • Cough Assist • 4 sets of 5 breaths