SLEEP STUDY INTERPRETATION: This sleep study was done on MM/DD/YYYY. It was on split-night evaluation with full-attended PSG recording and CPAP titration, CPAP titration in the second part of the night.
The patient is a (XX)-year-old male, 5 feet 10 inches tall, weight 212 pounds and BMI of 30, overweight. The patient is complaining of nonrefreshing, frequently interrupted sleep with loud snoring with strong clinical suspicion of obstructive sleep apnea, referred for a sleep study evaluation. Epworth Sleepiness Scale score was 4, which is in normal range.
MEDICATIONS: The patient is on multiple medications, including sertraline, different insulins, levothyroxine, meclizine, metformin, metoprolol, simvastatin and tamsulosin as well as different vitamins.
Full attended polysomnography was performed. Standard sleep montage was used, included 6 channels of EEG, left and right EOG, 3 chin EMGs, snoring sensor, airflow measured by oral-nasal thermistor and nasal pressure transducer, respiratory effort measured by thoracic and abdominal respiratory inductance plethysmography, pulse oximetry, left and right anterior tibialis EMG, EKG, body position and integrated digital audio and video recordings. Sleep and event scoring were performed in accordance with the AASM Manual for Scoring of Sleep and Associated Events, 2007. The whole study lasted for 8 hours and 3 minutes.
FINDINGS: In the first pre-CPAP period, which started at 22:16, the patient’s total sleep time was slightly above 2 hours 138 minutes due to very low sleep efficiency of only 60%. Sleep onset latency was prolonged, up to almost 34 minutes. REM sleep did not occur in this first part of the study, which lasted for 230 minutes.
Sleep architecture was quite unstable with frequent awakenings and arousals. Arousal index was almost 46 and awakening index was 9. Quite loud snoring was observed and recorded during that phase of the study.
Also very frequent periodic limb movements revealed with PLM index of 16, but none of those movements were associated with arousals.
Respiratory rate was 14, heart rate between 95 and 68 beats per minute with occasional infrequent PVCs. No parasomnias, alpha intrusions or delta arousals revealed.
Respiratory disturbances were very frequent and quite severe. The patient had 35 episodes of obstructive apnea, 5 episodes of central apnea and multiple mixed and obstructive hypopneas resulting in apnea/hypopnea index of 73.2.
Saturation dropped from highest level of 98% down to 90%.
After the patient met criteria for severe obstructive sleep apnea, CPAP titration was initiated. For that procedure, the patient wore a ResMed medium sized Quattro Air full face mask. Pressure range was applied between 4 and 14 cm of water.
In this second CPAP period, total sleep time was again close to 2 hours 134 minutes, and sleep efficiency was also quite low at 53%. Sleep onset latency was also slightly prolonged up to 33 minutes. REM sleep occurred with normal REM latency of 130 minutes and it lasted for 37minutes, taking 27.5% of total sleep time with some degree of rebound to compensate for the lack of REM sleep in the first part of the night.
Stage N3 was somewhat reduced down to below 13% of total sleep time, which is not really abnormal for that advanced age of the patient.
Stage N2 was reduced to less than 22% of total sleep time, probably because of significant predominance of drowsiness, early stage of sleep, stage N1, which took 38% of total sleep time.
During CPAP support, sleep architecture was still unstable, though a little bit more steady than before respiratory treatment was started. Still, arousal index was close to 36 and awakening index was even higher at 17. In the same time, periodic limb movements decreased in frequency, PLM index dropped down to less than 4 and only on 1 occasion periodic limb movement was associated with arousal.
Respiratory rate was 13. Heart rate between 89 and 66 beats per minute with no clinically significant irregularities. Snoring was suppressed completely at the highest level of pressure applied and actually only at that level of pressure of 14 cm of water resulted in significant improvement of respiratory events during this night evaluation.
The patient slept on that level of pressure for almost 103 minutes and at least 1 hour, quite prolonged episode of REM sleep with the patient in supine position occurred during that time. Apnea/hypopnea index dropped from baseline level of 73 down to 13, which is significant improvement but still not reaching normal range. Oxygen saturation was also more stable, never dropping below 93%, and as mentioned above, snoring was completely eliminated, and the periodic limb movements had become less frequent. That level of pressure was well tolerated, appliances was also tolerated reasonably well.
IMPRESSION AND RECOMMENDATIONS: This sleep study revealed severe obstructive sleep apnea, which eventually responded to a higher level of CPAP support at the pressure of 14 cm of water using a ResMed medium size Quattro Air full face mask.
It resulted in significant improvement in respiratory parameters and could be regarded as acceptable for initial CPAP treatment of this patient, but in case of insufficient efficacy, another all night study with CPAP titration should be considered.
Also, BiPAP mode could be considered during that trial if necessary if CPAP is not sufficiently effective even at the pressure of 15 or 16 cm of water, but for the time being, a trial of pressure support at 14 cm of water.
