David Cunnington

Scoring polysomnography respiratory events: the utility of nasal pressure and oro-nasal thermal sensor recordings

OBJECTIVE To evaluate the clinical utility of nasal cannula/pressure (NP) and oro-nasal thermal sensor (Th) recordings, alone and in combination for scoring respiratory events during routine diagnostic polysomnography (PSG). BACKGROUND The use of Th devices to measure airflow during PSG is not recommended because Th are insensitive to airflow changes other then complete airflow cessation. It has been suggested that NP recording is a better measure of airflow and can also detect increased upper airway resistance during PSG. METHODS Thirty consecutive PSGs were examined using 13 standard channels including Th and NP recordings. Respiratory events were scored separately utilizing NP+Th, Th alone and NP alone in a blinded fashion using modified AASM criteria. Respiratory events were time matched to within 5 s for each of the recording methods. RESULTS NP+Th detected more events than Th alone (P<0.0001); NP+Th detected more events than NP alone (P<0.0001) and NP alone detected more events than Th alone (P<0.0001). For AHI >50, NP alone and Th alone each detected 90% of matched NP+Th events. However, for AHI <50, NP alone detects 54% and Th alone detects 42% (P<0.005) of matched NP+Th events. For AHI >50, NP alone scored 97% of matched Th alone scored respiratory events, and Th alone scored 94% of NP alone scored respiratory events (P>0.05). However, for AHI<50, NP alone scored 90% of matched Th alone scored respiratory events, whereas Th alone scored 62% of matched NP alone scored events (P<0.0001). CONCLUSIONS In severe sleep disordered breathing (AHI >50), NP+Th, NP alone and Th alone have similar ability to detect respiratory events. When AHI <50, NP+Th appears better for detecting respiratory events than NP or Th alone. If only one measure of airflow is used, NP detects more events than Th.

Cardiorespiratory function in stable methadone maintenance treatment (MMT) patients.

Patients in methadone maintenance programmes (MMT) often smoke tobacco and cannabis and many have ongoing illicit drug use. There is therefore potential for these patients to have abnormal cardiorespiratory function; however, few studies address this in stable MMT patients. We assessed resting cardiorespiratory function on 50 stable MMT patients (25 males, 25 females). Forty‐six MMT patients were current tobacco smokers, 19 were current cannabis users and none were currently using opioids other than prescribed methadone. We defined abnormalities of respiratory function as those results outside the 95% confidence interval of reference values for normal subjects adjusted for age, weight, height and sex. Thirty‐one (62%) MMT patients had reduced carbon monoxide transfer factor (D L CO); 17 (34%) had elevated single breath alveolar volume (V A) and 43 (86%) had a reduced D L CO/V A ratio. Six patients (12%) had reduced FEV 1; one (2%) had reduced FVC; and nine (18%) had an obstructive ventilatory defect. Ten (20%) patients had PaCO 2 higher than 45 mmHg and 14 (28%) had alveolar to arterial oxygen gradient (A‐aPO 2) higher than 15 mmHg. CXR, Echocardiography and ECG showed no significant abnormalities. We conclude that stable MMT patients have abnormalities of resting respiratory function which may be due to ongoing tobacco cigarette and current or past cannabis smoking.

Australasian Sleep Association position statement regarding the use of psychological/behavioral treatments in the management of insomnia in adults

Insomnia disorder is a high prevalence condition with a high disease burden, which, left untreated, can increase risk of poorer health outcomes. Due to Insomnias tendency towards having a chronic course, long-term treatment approaches are required to reduce the impact of Insomnia over time. After reviewing the available literature, The Australasian Sleep Association (ASA) recommends Cognitive Behavior Therapy for Insomnia (CBT-I) as a first line treatment in the management of Insomnia. The ASA notes that in addition to CBT-I, there is emerging evidence for the use of Mindfulness Based Therapy for Insomnia when used in combination with behavioural techniques (MBT-I). CBT-I should be used whenever possible, and medications should be limited to the lowest necessary dose and shortest necessary duration. CBT-I, whilst the most effective long-term treatment, does not work for everybody across all circumstances, so there will be circumstances in which other treatments are required (e.g., pharmacotherapy). Improving access to CBT-I is an important issue which will involve raising awareness of the effectiveness of CBT-I, increasing the number of trained practitioners, and the development of effective low intensity treatments that can be offered in the first instance.