What are hemodynamic changes in sleep?

Hemodynamic changes in sleep could be caused by breathing disorders. These are common and have been associated with the mortality rate. So what are hemodynamic changes in sleep? Recent epidemiological studies have shown a firm association between these morbidity and mortality rate and these two factors also contribute to stroke.The hemodynamic changes along with the metabolic and hematologic changes during sleep-related breathing disorders could be the possible pathogenetic mechanisms for stroke. There are evidences stating that sleep apnea disorder may cause diurnal hypertension. The increased risk of stroke with sleep-related breathing disorders among patients, according to experiments appears to be independent of coexisting hypertension. The presence of hypertension has chances of aggravating the risk further. There are various studies which has evidence that high prevalence of sleep apnea disorders among patients who have transient ischemic attacks and stroke. From the studies, there have been conclusions that sleep-related breathing disorder is a major contributor as a risk factor for stroke via hemodynamic and hematologic changes. Since there is high prevalence of sleep apnea disorder, evaluation has to be done for patients having these disorders.

Obstructive sleep apnea syndrome is common phenomenon. It affects 2% to 4% of the adult population. If you look at the American population, there are 31 million people aged 65 years and older; more than 7 million are affected by sleep apnea. The state of sleep has a deep impact on cerebral hemodynamics.

Hemodynamic changes in sleep can also affect eyes, according to doctors. Some patients having obstructive sleep apnea usually have a high risk of glaucoma. According to a study conducted in Florida, 33% of patients with obstructive sleep apnea were detected to have glaucoma. By screening patients with obstructive sleep apnea may help identify patients having glaucoma. This will go undetected otherwise.

Obstructive sleep apnea syndrome is known by repeated apneic episodes which happens while sleep and also by daytime symptoms. These symptoms include excessive daytime sleepiness and chronic fatigue. The apneas are due to the collapse of pharyngeal airway. The duration of this is between 10 and 60 seconds. Apneas come along with hemodynamic changes. Apart from that there is a transient rise in blood pressure. Most of the patients do not know about the nocturnal events in spite of it happening many times during the night.

The diagnosis of OSAS is done by simultaneous measurement of electroencephalography, electromyography, electrocardiography, nasal and buccal airflow and pulse oximetry to measure arterial oxygen saturation. From the experiment results, the respiratory disturbance index (RDI) is calculated. This data represents the total number of apneas and hypopneas divided by the hours of sleep. An RDI score which is equal to or higher than 10 in combination along with the most seen symptoms indicates the presence of OSAS.