Sleep and Breathing Davina Lovegrove Senior Scientist & Training Coordinator Respiratory and Sleep Specialists

Sleep – Why do we need it? Restorative function for brain Learning and memory Repair of cells and healing Hormone secretions Energy conservation

How much is enough? Children and teenagers – average of 10 hours per night Adults – Average of 8 hours per night Hours of sleep /night

Consequences of reduced sleep Day time tiredness Reduced reaction times Mood disturbances Fatigue & muscle weakness Headaches Double vision Reduced motivation……..

Sleep Hygiene What is sleep hygiene? Sleep quantity Bedroom / sleep routine – Regular bedtimes – Routine before bed * – Dark environment – No bright lights – No pets in the room – No TV, computers & work in bed – Caffeine intake

Sleep Disorders Sleep Apnoea Insomnia Narcolepsy Periodic Limb Movements Insufficient sleep syndrome Post Traumatic Hypersomnia Obesity Hypoventilation Respiratory Failure Night Terrors REM Behaviour Disorder Nocturnal Epilepsy

Obstructive Sleep Apnoea What is OSA? repeated obstruction of the upper airway during sleep causing; – reduction in blood oxygen saturation – frequent sleep disturbance Phillips & Naughton, 2004

How do we diagnose OSA? Risk factors – Obesity – Family history – Age – Smoking – Alcohol / sedative use Questionnaires – Epworth sleepiness scale Overnight sleep study (PSG)

How do we diagnose OSA? Clinical Examination – risk factors

What happens when an individual obstructs? Normal Airway

Snoring What happens when an individual obstructs?

Apnoea What happens when an individual obstructs?

Slide courtesy of Dr Darren O’Brien

Consequences of OSA Sleep disruption Headaches Hypertension Heart disease (heart failure, CAD) Type 2 diabetes / insulin resistance Increased risk of stroke Heart arrhythmias Intellectual deterioration Frequent urination at night Personality changes

SpO 2 BP Airflow Resp. effort

Treatment options Lifestyle changes – Weight loss – Drugs, alcohol, smoking – Sleep hygiene Positional therapy Surgery – Tracheostomy – Uvulopalatopharyngoplasty – Gastric, bariatric Sx Oral appliances CPAP/APAP/Bilevel Slide courtesy of Dr Darren O’Brien

Gold Standard treatment How it works – Air passes through a mask into your nose and/or mouth then into your throat, where the slight pressure acts as a splint to keep your airway open and prevent apnoeas, hypopnoeas and snoring. CPAP

First Patient on CPAP, RPAH, Sullivan et.al., Lancet 1981 Slide courtesy of Dr Darren O’Brien

Fixed Pressure CPAP Devices 10 cm H2O Fixed pressure throughout the night CPAP machines provide a single, fixed pressure through out the night. The intent of CPAP is to splint open the upper airway to prevent obstruction.

Auto Pressure CPAP Devices 4 cm H 2 O Beginning of obstruction Varying pressure throughout the night in response to events Auto pressure devices automatically adjust the pressure in response to changes in the patients airway. Results in lower overall mean pressure. ?increased comfort for patient.

Bi-level Devices (NIV) Bi-level systems deliver two different pressures – a higher pressure on inspiration (IPAP) – a lower pressure on expiration (EPAP) Acts as a non-invasive VENTILATOR (NIV) 4 cm H2O 10 cm H2O Inspiration Expiration

Why do we need bi-level? Breathing basics…. In order to breath IN our diaphragm and accessory chest muscles must contract to cause expansion of our rib cage and therefore air enters our lungs

When do we need bi-level? When our diaphragm cannot contract due to – Muscle weakness – Greatly increased load on the muscles – Restricted movement

Breathing basics – gas exchange With each breath our lungs transfer – Oxygen (O 2 ) from the air into our blood stream – Carbon dioxide (CO 2 ) from our blood into the air When we don’t breath adequately – Blood oxygen levels drop (hypoxia) – Blood carbon dioxide levels increase (hypercapnia) CO 2 O2O2 O2O2

Breathing basics Not breathing adequately is called HYPOVENTILATION Hypoventilation hypoxia + hypercapnia Hypoxia + hypercapnia = respiratory failure = hospital admission

How does bi-level help? Assist and support patient’s own breathing efforts Rest fatigued respiratory muscles Improve gas exchange by increasing tidal volume Prevent nocturnal hypoventilation Increase nocturnal O 2 levels Reduce nocturnal CO 2 levels Improve daytime blood gases Stabilise upper airway

Case study Chest wall restriction secondary to Poliomyelitis Undergoing a split night sleep study – ½ night as a diagnostic study – ½ night as a bi-level study

DxNIV

Research Simonds et al 1995: Outcomes of patients on home NIV were assessed over 5 years in 180 patients with chronic respiratory failure NIV very well tolerated in post-polio patients: – 100% (n=30) of patients were still compliant at 5 year follow-up (ie 100% survival at 5 years) – Blood oxygen (O2) and carbon-dioxide (CO2) levels were improved and maintained at 5 years

Research Leger et al NIV improved quality of life NIV reduced number of days in hospital (from an average of 34 days per year to 7 days per year) NIV improved sleep quality in 70% of patients Buyse 2002 NIV is more beneficial in terms of survival, blood gases, and lung function compared with long term oxygen alone in patients with kyphoscoliosis

Why use NIV as treatment? Improved sleep quality Improved quality of life Less hospital admissions Improved blood gases (CO 2 and O 2 ) Improved lung function