A 38-year-old obese male with severe OSA wakes up energized after being treated with CPAP set at a pressure of 25 cm H2O.

While working in a sleep disorders center, a sleep technician can expect to encounter all types of sleep disorders, from patients with rapid eye movement (REM) behavior disorders, periodic limb movements, and night terrors, to those who suffer from bruxism. The most common sleep disorder seen at most centers is sleep-disordered breathing (SDB). With the country, as a whole, encountering a medical crisis with obesity, technicians can expect to see patients with severe obstructive sleep apnea (OSA) arriving at the sleep center. With these types of patients, there may be, depending on a center’s protocol, an increase in the number of split-night studies being performed. These studies can be ordered by physicians or insurance companies, or performed as an emergency procedure. The emergency may be due to the severity of the patient’s SDB, oxygen saturation, or cardiac changes. Let’s begin with a breakdown of what the patient believes is the problem, a review of the physical examination, the split-night polysomnogram, and the recommended treatment plan. The following type of patient, while seeming to be extremely critical, is becoming more routine at the John T. Mather Memorial Hospital’s Sleep Apnea Center, Port Jefferson, NY. The patient made an appointment with the center due to complaints of frequent nocturnal awakenings, frequent trips to the restroom, and excessive daytime sleepiness (EDS).

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Figure 1a. The patient’s polysomnogram indicates severe OSA prior to CPAP therapy.
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Figure 1b. The patient’s polysomnogram improves with CPAP therapy at 25 cm H20.

Case History
The patient who presented at the sleep center was a 38-year-old male, 5’6" tall, weighed 220 pounds, and had a neck circumference of 18.5 inches. His body mass index (BMI) was 35.5, which is classified as obese. He worked a daytime desk job from 7:30 am till 5 pm or 6 pm at night, with very little or no exercise in his daily routine. The patient would nap for 1 to 2 hours once or twice per week and would wake up unrefreshed. The patient had a history of asthma and used a prescription inhaler “once in awhile.” His Epworth Sleepiness Score was 22 out of 24. His bed partner witnessed apneas, loud snoring, and tossing and turning. The patient stated that he had difficulty concentrating, had experienced near car accidents due to drowsiness, and was under stress at work as well as at home. He usually went to bed at 10 pm, and woke at 6 am on workdays and at 11 am on his days off. It took him less than 5 minutes to fall asleep, but woke every 1 to 1.5 hours, with an average of seven awakenings per night. He stated that he did not wake up refreshed in the morning, but was tired and groggy, and had headaches that resolved within 1 hour of awakening. The patient stated that he had gained 50 to 60 pounds within the past 2 to 3 years and was a smoker with a history of one to two packs per day for 25 years. He denied drinking alcohol, but consumed seven to eight cups of coffee per day. The patient also suffered from seasonal allergies, and his father was diagnosed with OSA.

A physical examination revealed a heart rate of 91 and a room air saturation of 93% to 96%. His pharyngeal inlet was narrow, tonsils were present, and the nasal airway was narrow. Lung sounds were clear, heart sounds S1S2, abdomen soft, but severe edema in the extremities. The impression was that the patient exhibited signs and symptoms of severe OSA and possible congestive heart failure (CHF).

Plan of Action
The plan included a split-night polysomnogram for the evaluation and treatment of SDB, weight loss, exercise, and oral surgery if CPAP therapy was not tolerated.

The split-night polysomnogram results included the patient sleeping for 434 minutes (7.2 hours) out of 472 minutes (7.9 hours) for a sleep efficiency of 92% (normal value). The patient was asleep when the study began, which indicated excessive sleepiness. Stage 2 latency was 11 minutes, slow wave sleep (SWS) latency was 32 minutes, and REM sleep latency was 159 minutes (mildly prolonged). Stage 1 constituted 9.4%, stage 2: 35.3%, SWS: 21.2%, and REM sleep: 34.2%, which was elevated. All of the REM sleep noted occurred while the patient was on CPAP therapy.

Prior to the onset of CPAP therapy, the patient was in bed for 128 minutes and slept for 107 minutes. There were 169 apneas/hypopneas noted for an overall index of 94.8 events per hour of sleep. The patient’s SDB was associated with desaturations as low as 55%. There were 175 electroencephalographic (EEG) arousals noted for an arousal index of 98.1 arousals per hour of sleep (see Figure 1a, page 14). The patient slept on his right side prior to CPAP therapy.

The patient was fitted with a full-face mask due to his stating that he was a mouth breather, had facial hair, and suffered from nasal congestion. CPAP was initiated at a pressure of 4 cm H2O and titrated for apneas, hypopneas, respiratory effort-related arousals, and snoring. The patient was titrated with pressure up to 25 cm H2O within 51 minutes of initial CPAP therapy. The patient slept for 283 minutes on CPAP set at 25 cm H2O pressure. There were 19 apneas/hypopneas noted for an index of 4.0 apneas/hypopneas per hour of sleep (well within an acceptable range). There were 49 arousals noted for an index of 10.4 arousals per hour of sleep (slightly elevated, but acceptable due to the testing conditions). The patient had REM sleep while in the supine position without significant desaturations or respiratory events. The patient’s saturation normalized while on CPAP set at a pressure of 25 cm H2O (see Figure 1b, page 14).

The morning questionnaire revealed that the patient slept very well, felt refreshed, and was willing to continue to use CPAP therapy at home. The patient stated that he did not wake up during the test nor did he gasp or snore.

Follow-Up Visit
Upon a follow-up visit (within 72 hours of his study), the patient indicated that he felt refreshed the day after the study, and was more energetic and not sleepy, as compared to his previous days. CPAP pressure of 25 cm H2O with a heated humidifier, ramp, and full-face mask was ordered and set up for the patient. Educating the patient and follow-up for compliance with CPAP therapy were also done.

With the prevalence of obesity on the rise in this country, we can expect to encounter more patients in the laboratory with severe enough SDB to require split-night polysomnograms with increasingly higher CPAP pressures.

Russell E. Rozensky, RRT, RPSGT, CPFT, is supervisor, and Bernadette K. White, RRT, RPSGT, is lead technician, both at John T. Mather Memorial Hospital Sleep Apnea Center, Port Jefferson, NY.