Challenging Cases in Pediatric Polysomnography. Fauziya Hassan, MBBS, MS Assistant Professor Pediatric Pulmonary and Sleep

Transcription

1 Challenging Cases in Pediatric Polysomnography Fauziya Hassan, MBBS, MS Assistant Professor Pediatric Pulmonary and Sleep

2 Conflict of Interest None pertaining to this topic Will be using some slides from Respironics

3 Outline Physiology of CO2 monitoring Challenges of neuromuscular disorders Central hypoventilation

4 End Tidal CO 2 monitoring In a normal lung CO 2 rapidly diffuses across the capillary alveolar membrane with ventilation and perfusion well matched EtCO 2 reading is the PCO 2 equivalent to airway CO 2 concentration at the end of exhalation which approximates arterial PCO 2 (slightly higher than by 4 mm Hg)

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6 End Tidal CO2 Errors Increase in dead space ventilation-underestimates arterial PCO 2 Incomplete exhalation before next mechanical breathsmall airways obstruction Smaller tidal volumes among children Leaks Increase in physiologic dead space - low cardiac output states e.g. PE, blood loss - hypothermia - hyperventilation

7 Conditions for End Tidal CO2 monitoring Neuromuscular diseases Duchenne muscular dystrophy myotonic dystrophy SMA diaphragmatic paralysis cerebral palsy poliomyelitis congenital muscle diseases

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9 PSG in Infant

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25 History Of Present Illness 5 year old boy born full term was transferred from OSH for evaluation of rapid weight gain and sleep apnea Sleep study within the first year showed minor issues may need adenotonsillectomy Healthy until age 4 years. He gained 66 pounds in 10 months. Hyperphagia noted. Loud snoring with gasping and snorting arousals

26 History Of Present Illness PSG- obstructive sleep apnea and T&A done in October Slight improvement after T&A; he still snores and has pauses in breathing PSG with ETCO 2 monitoring (2012), demonstrates severe OSA (AHI of 30.8) Minimum oxygen saturation was 61% He also has hypoventilation with the sleep study, ETCO 2 more than 50 mmhg (414.2 minutes out of total sleep time of minutes)

27 History of Present Illness Titration study (July 2012) - did not respond well to CPAP. Switched to bi-level support with some improvement with pressure of 14/8 cm of water. However, severe treatment emergent central apnea rapidly developed. Further adjustment in the pressure made no difference Initial BiPAP setting 20/15 cm of water and with oxygen 3 liters per minute. Three weeks later, his sleep doctor lower his BiPAP setting to 14/8 with oxygen supplementation of 2 liters per minute

28 Sleep Study UMHS Venous blood gas - PCO 2 of 62 mm Hg and ph of 7.21 Split night study (TCO 2 ) monitoring. Baseline portion of the study - severe OSA and hypoventilation with paradoxical respiration, worse during REM sleep. Initial baseline oxygen saturation was low (82-84%) and oxygen via nasal cannula was added at 0.5 LPM. TCO 2 values prior to oxygen supplementation was between mm Hg and increased to mm Hg. The ETCO 2 spot checks at 53 mm Hg and TCO 2 values at 67 mm Hg

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30 Modes of Non-Invasive Ventilation Non invasive positive pressure ventilation BiPAP (bi-level positive airway pressure) BiPAP with ST mode (spontaneous-timed) BiPAP with T mode (timed) BiPAP with PC mode (pressure control) Average Volume Assured Pressure Support (AVAPS) with ST mode AVAPS with PC mode

31 Trigger to IPAP

32 BiPAP in PC vs. ST mode Triggered breaths

33 BiPAP with Inability to Trigger IPAP

34 BiPAP with Inability to Trigger IPAP

35 BiPAP with ST Mode

36 BiPAP with ST (Lower Tidal Volume with Spontaneous Breaths)

37 Next Case New patient 49 yr old male OSA, CSA (diagnosed 2000), pulmonary hypertension, hyperlipidemia, central hypoventilation syndrome Persistent daytime fatigue and sleepiness despite using backup rate of 18. Excellent compliance noted on ASV. Now has difficulty with maintaining oxygen saturations during day and night time oxygen desaturations to 70s noted Excessive daytime fatigue and sleepiness, currently sleeping about 10 to 12 hours every night and also taking Nuvigil 250 milligrams daily and Ritalin 10 milligrams twice daily

38 Next Case He was started on BiPAP with O2, initially, he was on 2 liters of oxygen, which was recently changed to 4 liters per minute Currently, on ASV machine with EPAP min 5 cm, max of 12 cm, pressure support 6-13, maximum pressure of 18 and a backup rate of 18 with Bi-Flex of 2 and 3 liters of oxygen during the day and 4 liters at home Last ABG - pco 2 of 72 mm Hg. Last titration (December 2014) with total sleep time of 215 minutes and his apnea-hypopnea index on that study was 3.1, baseline oxygen saturation of 92.8% (nadir O2 of 78%) PFT - FEV1 98%, FVC - 90% FEV1/FVC ratio 80% O2 saturation 96% at rest on room air

39 AVAPS AVAPS (Average Volume Assured Pressure Support) is available in S (spontaneous) S/T (spontaneous/timed) PC (pressure control) T (timed) modes Helps maintain the tidal volume by automatically controlling the pressure support by varying the IPAP between the IPAP minimum and IPAP maximum settings

40 Indications Patients with hypoventilation-either central or peripheral congenital central hypoventilation syndrome (CCHS) or acquired hypoventilation neuromuscular diseases - muscular dystrophy, spinal muscular atrophy (SMA) amyotrophic lateral sclerosis (ALS) restrictive lung disease - neuromuscular scoliosis AVAPS is also indicated in patients with COPD and obesity hypoventilation

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42 AVAPS Averaged Volume Assured Pressure Support AVAPS automatically adjusts the pressure support according to the patient s needs to maintain an average tidal volume. IPAP max IPAP IPAP min EPAP Target Vt Confidential Sector, MMMM dd, yyyy, Reference

43 Averaged Volume Assured Pressure Support What is AVAPS? AVAPS automatically adapts pressure support to patient needs to guarantee an average ventilation IPAP Max < 1 cmh 2 O/min IPAP Min EPAP Target Vt Vte = Vt patient Confidential Internal use only

44 Next Case New patient 49 yr old male OSA, CSA (diagnosed 2000), pulmonary hypertension, hyperlipidemia, central hypoventilation syndrome Persistent daytime fatigue and sleepiness despite using backup rate of 18. Excellent compliance noted on ASV. Now has difficulty with maintaining oxygen saturations during day and night time oxygen desaturations to 70s noted Excessive daytime fatigue and sleepiness, currently sleeping about 10 to 12 hours every night and also taking Nuvigil 250 milligrams daily and Ritalin 10 milligrams twice daily

45 Next Case He was started on BiPAP with O2, initially, he was on 2 liters of oxygen, which was recently changed to 4 liters per minute Currently, on ASV machine with EPAP min 5 cm, max of 12 cm, pressure support 6-13, maximum pressure of 18 and a backup rate of 18 with Bi-Flex of 2 and 3 liters of oxygen during the day and 4 liters at home Last ABG - pco 2 of 72 mm Hg. Last titration (December 2014) with total sleep time of 215 minutes and his apnea-hypopnea index on that study was 3.1, baseline oxygen saturation of 92.8% (nadir O2 of 78%) PFT - FEV1 98%, FVC - 90% FEV1/FVC ratio 80% O2 saturation 96% at rest on room air

46 Thank you