The role of dopamine in directly modulating somatic motoneuron excitability and hence muscle tone is unknown. We investigated whether dopamine influences the trigeminal motor pool (MoV) that innervates the masseter and tensor palatini muscles, both of which function to maintain upper airway patency. We hypothesized that dopamine facilitates motor outflow at the MoV. We focally applied apomorphine (nonspecific dopamine receptor agonist) at the MoV in anaesthetized rats. We also applied receptor-specific agonists and antagonists to determine the receptor subtype mediating dopaminergic mechanisms of action. We demonstrated that dopaminergic transmission at the MoV potently increased motor outflow via the D1-like receptor and facilitated masseter and tensor palatini muscle tone. It is unknown whether endogenous dopamine release on to airway motoneurons influences their activity to regulate muscle tone in natural sleep-wake behaviours. This issue warrants investigation because the neurochemical basis of upper airway motor dysfunction (e.g. obstructive sleep apnea) remains poorly characterized.

No description available.

Background: Obstructive sleep apnea is a common disorder, especially in men. Patients with this condition often snore and suffer from excessive daytime sleepiness. It is a treatable condition related to cardiovascular disease, road traffic accidents and obesity. Aims: To study whether snoring and witnessed sleep apnea are related to diabetes mellitus and whether sleepy subjects who snore or report sleep apneas drive more than others. To investigate whether sleep apnea is related to stroke, mortality and myocardial infarction in patients with coronary artery disease. To study the effect of ambient temperature on sleep apnea, morning alertness and sleep quality in patients with obstructive sleep apnea. Methods and results: Questions on snoring, sleep apnea, daytime sleepiness and yearly driving distance were included in the northern Sweden component of the WHO MONICA study. Analyzed were 7905 randomly selected men and women aged 25-79 years. Snoring and witnessed sleep apnea were related to diabetes mellitus in women, (OR 1.58, p = 0.041 and OR 3.29, p = 0.012 respectively), independent of obesity, age and smoking, but not in men. Sleepy snoring men drove a mean of 22566 km per year which was more than others who drove 17751 km per year independent of age, BMI, smoking and physical activity (p = 0.02). Sleepy men reporting sleep apnea also drove more (p = 0.01). 392 men and women with coronary artery disease referred for coronary angiography were examined with overnight sleep apnea recordings and followed for 10 years. Sleep apnea was recorded in 211 (54%) of patients at baseline. Stroke occurred in 47 (12%) patients at follow up. Sleep apnea was associated with an increased risk of stroke (HR 2.89, 95% CI 1.37 - 6.09, p = 0.005) independent of age , BMI, left ventricular function, diabetes mellitus, gender, intervention, hypertension, atrial fibrillation, a previous stroke or TIA and smoking. The risk of stroke increased with the severity of sleep apnea. 40 patients with obstructive sleep apnea were investigated with overnight polysomnography in ambient temperatures of 16°C, 20°C and 24°C in random order. Total sleep time was a mean of 30 minutes longer (p = 0.009), sleep efficiency higher (p = 0.012), patients were more alert in the morning (p = 0.028), but sleep apnea was more severe when sleeping in 16°C (p = 0.001) and 20°C (p = 0.033) vs. 24°C. The AHI was 30 ± 17 in 16ºC room temperature, 28 ± 17 in 20°C and 24 ± 18 in 24°C. Conclusions: Snoring and witnessed sleep apneas are related to diabetes mellitus in women. Sleepy men who snore or report sleep apnea drive more than others. Sleep apnea is independently associated with the risk of stroke among patients with coronary artery disease. Subjects with obstructive sleep apnea sleep longer, are more alert in the morning after a night’s sleep, but sleep apnea is more severe when sleeping in a colder environment.

Methadone is a long acting mu-opioid and is the most effective treatment for heroin addiction. However, opioids depress respiration and methadone maintenance treatment (MMT) patients have a higher mortality rate than the general population. Teichtahl et al conducted a pilot study and found 6 out of 10 MMT patients had central sleep apnea (CSA). But no definite conclusions were made regarding the prevalence and possible pathogenesis of CSA in the patients due to the small sample size and lack of blood toxicology data. The present project aims to confirm the preliminary results and further quantify the sleep disordered breathing (SDB) in stable MMT patients and to delineate the pathogenesis involved. (For complete abstract open document)

Sleep disruption has been implicated in morbidity after major surgery since 1974. Sleep-related upper airway obstruction has been associated with death after upper airway surgery and profound episodic hypoxaemia in the early postoperative period. There is also evidence for a rebound in rapid eye movement (REM) sleep that might be contributing to an increase in episodic sleep-related hypoxaemic events later in the first postoperative week. Speculation regarding the role of REM sleep rebound in the generation of late postoperative morbidity and mortality has evolved into dogma without any direct evidence to support it. The research presented in this thesis involved two main areas: a search for evidence of a clinically important contribution of REM sleep rebound to postoperative morbidity, and a re-examination of the role of sleep in the causation of postoperative episodic hypoxaemic events. To assess the latter, a relationship between airway obstruction under anaesthesia and the severity of sleep-disordered breathing was sought. In 148 consecutive sleep clinic patients, 49% of those with sleep-disordered breathing (SDB) had a number of events in non-rapid eye movement sleep (NREM) that was greater than or equal to that in REM and 51% had saturation nadirs in NREM that were equal to or worse than their nadirs in REM. This suggests SDB is not a REM-predominant phenomenon for most patients. Of 1338 postoperative deaths occurring over 6.5 years in one hospital only 37 were unexpected, most of which were one or two days after surgery with no circadian variation in the time of death, casting further doubt on the potential role of REM rebound. Five of nine subjects studied preoperatively had moderately severe SDB. Unrecognised and significant SDB is common in middle-aged and elderly patients presenting for surgery suggesting overall perioperative risk of important adverse events from SDB is probably small. In 17 postoperative patients, sleep macro-architecture was variably altered with decreases in REM and slow wave sleep while stage 1 sleep and a state of pre-sleep onset drowsiness, both associated with marked ventilatory instability, were increased. Sleep micro-architecture was also changed with an increase in power in the alpha-beta electroencephalogram range. These micro-architectural changes result in ambiguity in the staging of postoperative sleep that may have affected the findings of this and other studies. Twenty-four subjects with airway management difficulty under anaesthesia were all found to have some degree of SDB. Those with the most obstruction-prone airways while anaesthetised had a very high incidence of severe SDB. Such patients warrant referral to a sleep clinic.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Thesis (Ph.D.)--University of Melbourne, Dept. of Medicine, Western Hospital, 2007. / Typescript. Includes bibliographical references (leaves 145-181).

Thesis (Ph. D.)--University of Sydney, 2003. / Includes tables and questionnaires. Title from title screen (viewed Apr. 29, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Faculty of Medicine. Degree awarded 2003; thesis submitted 2002. Includes bibliography. Also available in print form.

Στην διπλωματική εργασία αυτή παρουσιάζεται ένα μικρό σύστημα εντατικής παρακολούθησης. Παρουσιάζεται πλήρως η κατασκευή ενός οξύμετρου παλμού από πλευράς hardware και software αφού αυτό είναι συνδεδεμένο σε έναν κεντρικό υπολογιστή. Στο τέλος πήραμε μερικά δείγματα από άτομα εθελοντές για να δείξουμε πως λειτουργεί αυτό που έχει κατασκευαστεί. Επίσης παρουσιάζεται μια καινοτόμος ιδέα για την αντιμετώπιση του προβλήματος της υπνικής άπνοιας, που αφορά όχι τόσο πολύ στο θέμα πρόληψη, αλλά στην αντιμετώπιση δύσκολων, ακραίων καταστάσεων. / The current thesis presents a patient’s monitoring system for emergency rooms. It fully presents the construction of a pulse oximeter, including software and hardware development, which is connected to a server computer. Finally, some samples were taken from various volunteers to show how the pulse oximeter works. Also, the thesis presents an innovative idea for the problem of sleep apnea, for dealing critical situations.