BiPAPS/TVAPSCPAPASV???? Lori Davis, B.Sc., R.C.P.T.(P), RPSGT

BiPAPS/TVAPSCPAPASV???? Lori Davis, B.Sc., R.C.P.T.(P), RPSGT

Modes Continuous Positive Airway Pressure (CPAP): One set pressure which is the same on inspiration and expiration Auto-PAP (APAP) - Provides the same pressure on inspiration and expiration over a range of pressures Primarily used to treat obstructive sleep apnea Pressure relief is available in the form of Expiratory Pressure Relief (EPR) with ResMed and C-Flex with Respironics Bi-Level Spontaneous: IPAP and EPAP are set. The difference between IPAP and EPAP (pressure support) helps determine the tidal volume Breaths are patient-triggered and patient-cycled. Switching from IPAP to EPAP is based on patient flow Cycles to EPAP if no patient exhalation effort is detected for 3 seconds Primarily used to treat CPAP intolerance, hypoventilation with SpO 2 < 90% and COPD

Modes (continued) Bi-Level Spontaneous/Timed (ST): IPAP and EPAP are set. The difference between IPAP and EPAP (pressure support) helps determine the tidal volume A back up respiratory rate is set Breaths are patient or machine triggered and patient or machine cycled Primarily used to treat defective central respiratory control or respiratory muscle weakness that lead to chronic respiratory failure Adaptive Servo-Ventilation (ASV): Fixed EPAP or EPAP range is set to control obstructive events Pressure support range in set. Pressure support is continuously adjusted to achieve a pre-determined target Primarily used to treat Central/Mixed and Complex Sleep Apnea and Cheyne- Stokes Respiration (CSR)

Pressure Relief and Bi-Level S C-Flex Off C-Flex of 1 C-Flex of 2 C-Flex of 3 EPR Off EPR of 1 EPR of 2 EPR of 3 CPAP of 10 Bi-Level S 10/9 Bi-Level S 10/8 Bi-Level S 10/7

Pressure Relief C-Flex 3 EPR 3

Case Study KB 61 year old morbidly obese female (BMI 52 kg/m 2 ), history of COPD, OSA, and episodes of acute respiratory failure Non-compliant with CPAP Was living in Long Term Care and wanted to remain there, but was transferred to West Park Healthcare Centre to initiate non-invasive ventilation Non-compliant with NIPPV BUT she lost 15 kg during her stay at West Park (BMI 46kg/m 2 )

Case Study KB June 2017 sleep study done with supplemental oxygen titrated to 0.5 L/minute RDI: 2/hour of sleep Mean SaO 2 88% (range 71-95%) and mean PCO 2 46mmHg (range 42-50mmHg)

Case Study KB February 2018 - BMI had increased to 52kg/m 2 Follow-up sleep study done with supplemental oxygen titrated to 1 L/minute RDI: 4/hour of sleep Mean SaO 2 90% (range 73-99%) and mean PCO 2 60mmHg (range 51-65 mmhg)

Case Study KB Returned to Long Term Care with stable respiratory status and compliant with CPAP at 12cmH 2 O with supplemental oxygen at 2L/minute Developed acute respiratory failure, was admitted to hospital and given auto-pap 10-15cmH 2 O with supplemental oxygen at 4 L/minute June 2018 - returned to West Park for follow-up. BMI now 60kg/m 2. Data download indicated that CPAP at 13cmH 2 O adequate Sleep study performed with CPAP and oxygen to assess respiratory failure She was unwilling to purchase a Bi-Level device

CPAP 15-17cmH2O with EPR of 3 and O2 2-3L/min

Case Study KB CPAP titrated from 15 to 17cmH 2 O with EPR set at 3 to mimic Bi-Level S. Supplemental oxygen was titrated to 3L/minute RDI: 2/hour of sleep Mean SaO 2 90% (range 70-98%) and mean PCO 2 63mmHg (range 51-68mmHg) CPAP at 16cmH 2 O with EPR at 3 with 3 L/min of supplemental oxygen was required to manage OSA and hypoxemia Goal to stabilize chronic respiratory failure and minimize recurrent episodes of acute respiratory failure To be continued.

Learnings EPR and C-Flex work differently One may be preferable over the other depending on the intended use Think outside the box!

Bi-Level Spontaneous/Timed (ST): IPAP and EPAP are set. The difference between IPAP and EPAP (pressure support) helps determine the tidal volume Back up respiratory rate is set Breaths are patient or machine triggered (machine triggers to IPAP when patient effort is weak or non-existent) Breaths are patient or machine cycled (machine cycles to EPAP when inspiratory time is too long) Additional features allow the clinician to optimize the patient s work of breathing, comfort and synchrony

Bi-Level Features Trigger and Cycle Sensitivities Responsiveness of machine to triggering inspiration and cycling to expiration. Based on patient flow Inspiratory Time The duration of inspiration. In general, longer inspiratory times improve oxygenation. Dependent on respiratory rate Rise/Fall Time The speed of the rise to IPAP during inspiratory time and fall to EPAP during exhalation

Bi-Level Features Volume Assured Pressure Support (VAPS) Automatically adjusts pressure support by varying IPAP levels to ensure a preset target volume is met. EPAP is set ivaps (Intelligent Volume Assured Pressure Support) by ResMed. Uses alveolar ventilation as the target volume and automatically adjusts back-up respiratory rate. AVAPS (Average Volume Assured Pressure Support) by Respironics. Uses average tidal volume as the target volume AVAPS-AE (Auto EPAP) automatically adjusts EPAP to maintain a patent airway AND pressure support to meet target volume VAPS is ideal for patients who may have large changes in minute ventilation during REM sleep, during body position changes or during disease progression

VAPS Example Respironics A-40 ST mode with AVAPS-AE Target tidal volume (Vt) = 600ml EPAP min-max = 11-15cmH 2 O Pressure Support (PS) min-max = 10-17cmH 2 O Respiratory rate (RR) = 16bpm Inspiratory time (T i ) = 1.0second What is the minimum IPAP level the machine will reach? Maximum? 21cmH 2 O and 32cmH 2 O

Obesity Hypoventilation Syndrome Obesity = BMI > 30kg/m 2 Morbid Obesity = BMI > 40kg/m 2 Hypoventilation = reduced minute ventilation resulting in elevated arterial carbon dioxide tension (PaCO 2 > 45mmHg) and reduced arterial oxygen tension (PaO 2 ) No other causes for hypoventilation Often overlaps with Central and Obstructive Sleep Apnea Some patients may respond to CPAP, others may require Bi-Level PAP or Bi-Level ST ventilation Differential Diagnoses: Severe COPD Chest wall disorders (Kyphoscoliosis) Hypothyroidism Neuromuscular disorder Congenital central alveolar hypoventilation syndrome

Case Study NP 55 year-old female with morbid obesity (BMI 77kg/m 2 ), Pulmonary Hypertension, COPD and OSA. OHS? Had been using CPAP at 10cmH 2 O with supplemental oxygen at 2 L/minute when she was referred to West Park Sleep study done November 2013 with CPAP titrated from 5 to 15cmH 2 O and supplemental oxygen titrated from 1 to 3L/minute

NP Nov. 2013 CPAP 5 to 15cmH 2 O + oxygen 1 3L/min

Case Study NP Mean SaO 2 was 88% (range 70-98%) Mean T C PCO 2 was 65mmHg (range 58-72mmHg) RDI: 3/hour of sleep with CPAP of 15cmH 2 O Respiratory failure with CPAP and supplemental O 2 What next???

Case Study NP Non-invasive ventilation initiated at West Park using Respironics A40 ST AVAPS AE: EPAP min-max = 11-15cmH 2 O, Pressure Support (PS) min-max = 10-17cmH 2 O, respiratory rate (RR) = 16bpm, target V t = 600ml, Ti = 1.0 second, max. pressure = 28cmH 2 O Follow-up sleep study done May 2014 on above parameters, without supplemental oxygen BMI: 77kg/m 2 Mean SaO 2 was 91% (range 81-98%) 3% with no supplemental oxygen Mean TCPCO 2 was 51mmHg (range 48-53mmHg) 14mmHg RDI: 6/hour of sleep

NP May 2014 A40 ST AVAPs AE, room air

Case Study NP Follow-up sleep study done December 2016 on same ventilator parameters without supplemental oxygen BMI: 68kg/m 2 Mean SaO 2 was 93% (range 81-98%) 2% Mean TCPCO 2 was 49mmHg (range 46-54mmHg) 2mmHg RDI: 5/hour of sleep

NP Dec. 2016 A40 ST AVAPS AE, room air

Learnings Patients with hypoventilation who do not respond to CPAP will likely benefit from non-invasive ventilation Unexplained nocturnal desaturations should alert you to the possibility of HYPOVENTILATION The guesswork is eliminated if you monitor CO 2

Case Study DC 70 year old male compliant with CPAP at 10cmH 2 O for 5 years with new complaints of poor sleep following craniotomy to remove brainstem tumor A sleep study elsewhere showed central respiratory events on CPAP. Bi-Level ST was tried but he felt no improvement is sleep quality or symptoms He was referred to West Park for consultation and management A sleep study was done with CPAP titrated from 5 to 12cmH 2 O RDI: 75/hour of sleep (mixed, obstructive and central events) Mean SaO 2 was 96% (range 91-99%). Mean TCPCO 2 was 40mmHg (range 34-46mmHg)

DC CPAP Titration (5 12cmH 2 O)

Case Study DC June 2016 a repeat sleep study was done to titrate ASV Used ResMed VPAP Adapt SV: Pressure support min-max = 3 8cmH 2 O The EPAP was titrated from 7 to 9cmH 2 O RDI: 2/hour of sleep significantly Increased wakefulness persisted

DC June 2016 ASV: PS min-max 3 8, EPAP 7 9cmH 2 O

Case Study 3

Case Study 3 z

Learnings ASV is an effective therapy in patients with central and mixed sleep apnea to stabilize variability in breathing patterns ASV controls respiratory events and maintains stable minute ventilation Machine data downloads help determine if settings have been optimized and guide clinical management * ASV is contraindicated in patients with LVEF <45% *

CPAP Bi-LEVEL S/ST VAPS ASV Lori Davis, B.Sc., R.C.P.T.(P), RPSGT