Sleep and breathing disorders

1. Regulation of the sleep-wake cycle
   1. Basic neural processes and transmitters that control wakefulness, non-rapid eye movement and rapid eye movement sleep states
2. Sleep architecture in a normal adult
   1. Ageing process from foetal life to old age affects the sleep cycle
   2. Gender differences in sleep

1. Factors that control breathing during sleep and wakefulness
2. Ventilatory response to hypercapnia and hypoxaemia (including loop gain), arousal and the apnoea threshold
3. Molecular mechanisms of hypercapnia and hypoxemia e.g. master regulators and signalling pathways involved
4. The pathophysiological concept of upper airway obstruction, arousability, muscle responsiveness, and loop gain
   1. Functional anatomy of the upper airway
   2. Morphologic and functional changes of upper airway muscles
   3. Arousal threshold
5. Pathophysiology of central sleep apnoea (CSA)
   1. Hypercapnic and non-hypercapnic CSA
   2. Chemoresponsiveness
   3. Apnoea threshold
6. Hypoventilation disorders
   1. Chemoresponsiveness
   2. Influence of respiratory mechanics and ventilation
      1. Sleep-related changes in respiratory mechanics in the aetiology of nocturnal hypoventilation

1. Cardiovascular function (e.g. blood pressure and heart rate) during sleep and arousal from sleep
2. Impact of sleep on autonomic regulation and the consequences of sleep pathology, e.g. in OSA and CSA

Utility of ABG, capillary blood gas and venous blood gas

1. Diagnosis of A-B disorders: Henderson-Hasselbalch equation and the relationship between partial pressure of oxygen (PO₂), partial pressure of carbon dioxide (PCO₂), pH and bicarbonates (HCO3)
2. A-B disorders: importance of the D(A-a) difference, fraction of inspired oxygen (FiO2), the alveolar gas equation and measuring oxygen shunts

1. Obstructive sleep apnoea hypopnoea syndrome (OSAHS), CSA, periodic breathing, Cheyne-Stokes respiration, obesity hypoventilation syndrome (OHS), nocturnal hypoventilation, upper airway resistance syndrome, Treatment Emerged Central Sleep Apnoea (TECSA)
2. Epidemiology of OSAHS, CSA and OHS
3. Clinical phenotypes of OSA and their relationship to the underlying pathophysiology

1. Sleep history including:
   1. Sleepiness and fatigue
   2. Insomnia
   3. Poor sleep quality
   4. Nocturnal choking and gasping
   5. Snoring
   6. Morning headaches
   7. Impotence
   8. Low mood or labile mood
   9. Cognitive impairment
   10. Differential diagnosis of sleepiness and insomnia, g. consider lifestyle choices, sleep hygiene and medication
2. Signs
   1. Clinical examination of the upper airway, nasal obstruction, tonsils and adenoids
   2. Craniofacial disorders
   3. Hypothyroidism
   4. Obesity
3. Comorbidities, e.g. COPD, Interstitial Lung Diseases (ILD’s), chest wall disease, neuromuscular or neurological disorders, cardiovascular disease and endocrine or metabolic disorders

1. Usage of questionnaires: Epworth sleepiness scale, STOP-BANG score, Berlin questionnaire and SF-36
2. Two-stage screening with limited sleep tests like nocturnal oximetry to further increase pre-test probability
3. Identification of high-risk patients, e.g. those with severe sleepiness, unstable cardiac disease, nocturnal arrhythmia or baseline hypoxaemia or those who drive or have another occupational risk

1. Methodology of different sleep tests (oximetry, respiratory polygraphy and full polysomnography (PSG))
2. Limitations of overnight oximetry, respiratory polygraphy (PG), and home versus hospital-based sleep studies
3. Appreciation of which patients to refer for PSG, g. those with an unclear diagnosis on respiratory polygraphy, with comorbidities, a poor treatment response or a suspected non-respiratory sleep disorder such as narcolepsy or restless leg syndrome
4. Identification of cases that require further specialised examinations, g.ear-nose-throat (ENT) review of the upper airway
5. Review of cardiovascular, respiratory and metabolic disorders often associated with OSA
6. High cardio-metabolic and driving risks associated with untreated OSA
7. Value of making lifestyle improvements including weight loss, exercise, adherence to drug treatment for hypertension or diabetes, smoking cessation and alcohol reduction

1. Role of capnography in patients with nocturnal hypoventilation
2. Limitations of overnight transcutaneous carbon dioxide (TCO2) and end-tidal carbon dioxide (ETCO2) monitoring
3. Use of capnography to establish ventilator settings

1. Distinguish mild, moderate and severe cases of OSA from normal results and upper airway resistance syndrome integrating add on to apnoea hypopnea index (AHI) parameters such as nocturnal hypoxic burden, or indices of Autonomic dysfunction, etc
2. Integrating the multicomponent grading system for OSA: the Baveno classification
3. Lifestyle interventions including weight loss, exercise, smoking cessation, alcohol reduction, avoidance of night sedation and sensible sleep hygiene measures
4. Role of ENT intervention
5. Role and types of mandibular advancement splints and other oral devices
6. Definition of positional sleep apnoea and the role of positional devices
7. Indications for continuous positive airway pressure (CPAP) therapy
8. Differences between fixed level CPAP, variable (automatic) CPAP (automatic positive airway pressure (APAP)), and bi-level positive pressure (BPAP) therapy
9. Identification of patients to refer for these interventions depending on local pathways
10. CPAP-related side effects such as interface problems, airway drying and sleep disturbance
11. Issues leading to poor adherence and how these may be addressed
12. TECSA: identify OSA patients at high risk of developing TECSA, how to diagnose and treat
13. Different ways of monitoring positive pressure therapy: clinic visits, data downloads from devices and telemonitoring
14. Follow-up including assessment of the efficacy of therapy in controlling OSA and also the impact on comorbidities and health-related quality of life
15. Importance of explaining the rationale and likely outcomes of treatment to patients and of providing advice about medico-legal aspects such as driving
16. Awareness and importance of following local guidelines on the diagnosis and management of OSAHS