STUDY : SPLIT-NIGHT POLYSOMNOGRAM

STUDY : SPLIT-NIGHT POLYSOMNOGRAM 


INDICATIONS


Ms. xxxxx is a 60-year-old lady presenting for re-evaluation of her obstructive sleep apnea syndrome.  Ms. xxxx was diagnosed several years ago with severe obstructive sleep apnea and has been off C-flex therapy for at least a couple of years.  She has had weight gain and worsening of sleep quality.  Please see Ms. xxxxx history and physical dictation for details of her presentation.  Ms. xxxxx underwent split-night polysomnogram testing at Thomas Hospital Sleep Services on May 13, 2009.   

DIAGNOSES


Obstructive sleep apnea syndrome, severe (327.23)


RESULTS  

There were 7.5 hours of recorded time and 6 hours of sleep recorded. The entire sleep time was spent in the nonsupine sleep position.  Total sleep efficiency was reduced at 80%.  Latency to sleep onset was prolonged at 47.5 minutes.  A 10-milligram dose of Ambien was given to help with sleep onset.  Latency to stage REM onset was prolonged at 126.5 minutes.  There were 15 awakenings for 42 minutes of awake time after sleep onset.  Sleep staging revealed an increase in percentages of stage I and stage II sleep with marked reduction in percentage of stage REM sleep and no stage III or stage IV sleep recorded.  The hypnogram revealed frequent awakenings and difficulty maintaining sleep stages with 2 periods of stage REM sleep after the initiation of C-flex therapy.

The average sleeping heart rate was 68 beats per minute.  A few PVCs were seen.  There was variation in heart rate with events of sleep-disordered breathing and arousals.  Moderate snoring was heard and this decreased with titration of C-flex therapy.  There were 5 periodic limb movements scored and 1 event was associated with arousal, no events were associated with awakening.  The total PLM index was 0.8.  The PLM index with arousal was 0.2.

There were 121 minutes of monitored time and 67.5 minutes of sleep time recorded without the benefit of C-flex therapy.  In that time, there were 67 obstructive apneas and 85 obstructive hypopneas scored for a total respiratory disturbance index of 135.1 consistent with a very severe obstructive sleep apnea syndrome.

Ms. xxxxxx was fitted with a ResMed Swift LT small interface and C-flex therapy was titrated over range of pressures from 4 to 9 cm of water.  Best results were seen at C-flex pressure setting of 9 cm of water and 56.5 minutes of sleep time recorded at this pressure setting.  In this time, there were no apneas and only 4 hypopneas for a respiratory disturbance index of 4.2, a remarkable improvement compared to the pretreatment respiratory disturbance index of 135.1.  In addition, Ms. xxxxx was able to enter and maintain stage REM sleep in the nonsupine sleep position at this pressure setting.  There were no significant hemoglobin desaturations and snoring was controlled at this pressure setting.  The lowest hemoglobin saturation recorded in this study was 83% with 97% of sleep time spent at hemoglobin saturations greater than 89%.

Ms. xxxxx awakened from the study feeling "tired."  She estimated it took about 30 minutes to fall asleep and that she awakened 4 times during the night sleep, an estimated 5 hours.  Her blood pressure study onset was 161/88 and 159/86 at the end of the study.

 
RECOMMENDATIONS


I will review these results with Ms. xxxxx and recommend she restart C-flex therapy at a pressure setting of 9 cm of water with a ResMed LT Swift size small interface with interface of her choice.  I will ask her to return in a couple weeks if she is having any initial problems with C-flex therapy.  She will be urged to avoid the supine sleep position.