Sleep is a fundamental aspect of good health, and getting enough sleep is essential for restoring the body and mind. Sleep studies have become increasingly popular in recent years to help identify sleep disorders and guide treatment interventions. However, interpreting the results of these studies can be challenging, often requiring specialized knowledge and training. Here, we will provide you with practical tips to master the art of decoding sleep study results.
What Is A Sleep Study?
A sleep study, also known as a polysomnogram , is an overnight test that monitors several physiological parameters during sleep using electrodes attached to the scalp, face, chest, limbs, and finger. These parameters include brain waves , eye movements , muscle tone , heart rate , breathing patterns , oxygen saturation levels , and snoring sounds.
The recorded data from a PSG is then analyzed by trained technicians or specialists who use specific guidelines or criteria to score various aspects of sleep physiology objectively. These scores help diagnose different types of sleep disorders like obstructive sleep apnea, narcolepsy, restless leg syndrome among others.
Understanding The Different Stages Of Sleep
Before we start decoding your sleep study results let us familiarise ourselves with different stages of human’s normal nightly sleeping cycle:
- Stage 1: This stage accounts for about 5% of our total time asleep; it’s considered lightest when drowsiness comes over us.
- Stage 2: This stage includes deeper relaxation than during Stage 1 – it accounts for almost half our night’s/rest-cycle accompanied by occasional activity such as rolling around or movement but presents no awareness.
- Slow Wave Sleep or Deep Sleep : It is during this phase that we experience an increase in physical relaxation and decreased physiological brain activity; it’s the period where our body restores itself and regains energy.
- REM Sleep: Rapid Eye Movement occurs between 70-100mins after going to bed, is marked by increased brain and eye activity, accompanied by rapid cycles of dreams.
How To Decode Your Sleep Study Results
The AHI score estimates the number of times per hour you stop breathing or experience shallow breathing events during sleep due to partial or complete obstruction in your airway. An AHI score below five indicates good respiration rates while above sixteen signifies severe apnea/hypopnea issues.
Respiratory Disturbance Index
The RDI evaluates the frequency of respiratory related disturbances such as obstructive hypopneas, central apneas, mixed apneas, respiratory effort-related arousals etc. It can help identify more subtle breathing problems which may have been overlooked before becoming significant issues with an RDI less than 10 reflecting insignificant concerns while scores greater than 30 signify critical disorder.
Oxygen Saturation Levels
Oxygen saturation measures how much oxygen your blood is carrying during sleep. Low levels of oxygen can occur when there is a decrease in airflow through the airways causing air limit or interruption leading to snoring/any form sound caused because of restricted airway flow known as ‘snore-related soungs’. This drop causes some people with OSA to wake up from deep sleep but a normal reading shows SpO2 >90% maintaining throughout achieving proper rest.
Mean Wakefulness After Sleep Onset
This parameter refers to the total time spent awake at night after falling asleep – think difficulty staying asleep! Waso amounts differ depending on age/gender however for young healthy adults believed between ~20-30mins although longer durations can be noted in extremes.
A hypnogram helps to understand sleep patterns over time, and typically uses visual cues representing different stages of your sleep cycle – simply ‘mapping out’ your evening rest activity recording its duration spent in each phase.
Frequently Asked Questions
How do I prepare for my Sleep Study?
Avoiding caffine intake before sleeping, getting relaxed and calm are a couple of preparations you could opt for. You may choose what makes you comfortable like bringing pajamas from home or listening to soft music; making the environment stress-free is key!
Can I take my usual medications on the night of a sleep study?
Ask your provider regarding specific medication instructions prior to going in as it varies by type/ use of medicines involved.
Should I bring anything with me to the Sleep Center?
It’s normal human behavior that whenever we travel, we want to carry stuff that keeps us at ease or things which provide comfort! Some centers may require patients wear loose fitting athletic attire or semi-formal clothing. Bringing personal hygiene products like toothbrushes/toothpaste should suffice added with gentle reminders about snug pyjamas, favorite blankets & pillows make sleeping away from home more enjoyable!
Interpreting sleep study results can be tricky but attaining knowledge about understanding various parameters will help you greatly and guide treatment if needed. The general rule is lower scores signify better quality of rest while higher ones demand intervention. Utilizing tips provided above will equip an individual with confidence needed while visiting their healthcare provider and discussing questions related to their own individual PSG results sheet!