JAMDA
Volume 10, Issue 3 , Pages 207-210, March 2009

Falling-Asleep–Related Injured Falls In The Elderly

  • Fannie Onen, MD, PhD

      Affiliations

    • Service de Gériatrie, CHU Bichat Claude Bernard, Paris, France
    • ,
  • Susan Higgins, MD

      Affiliations

    • Hospices Civils de Lyon, Service de Pneumologie Lyon-Sud, Pierre Benite, France
    • ,
  • S.-Hakki Onen, MD, PhD

      Affiliations

    • Hospices Civils de Lyon, Unité de Sommeil, Hôpital Gériatrique Antoine Charial, Francheville, France
    • Corresponding Author InformationAddress correspondence to S.-Hakki Onen MD, PhD, Hôpital Gériatrique Antoine Charial, 40, avenue de la Table de Pierre, 69340 Francheville, France

published online 12 January 2009.

Article Outline

Objectives

To describe the clinical features and therapeutic response to continuous positive airway pressure (CPAP) in elderly obstructive sleep apnea syndrome (OSAS) patients with sleepiness and falling-asleep–related injured falls.

Patients and methods

In 2 geriatric units, 4 consecutive OSAS patients with falling-asleep–related injured falls were diagnosed. They were treated with CPAP and followed for 9 to 24 months.

Results

Mean age at initial observation was 82 years. All patients shared the following characteristics: self-reported daytime sleepiness, falling-asleep–related injured falls, recurrent fall history, medical comorbid conditions, PSG confirmed OSAS, and successful treatment with CPAP. They declared resolution of sleepiness and attention without any further fall under CPAP therapy.

Conclusion

A causal relationship exists between OSAS and falling-asleep–related injured falls in the elderly. Treatment of OSAS with CPAP can improve attention, daytime vigilance, and consequently gait and balance control and prevent falls in these patients.

Keywords: Obstructive sleep apnea, daytime sleepiness, fall, elderly

 

About 30% of older adults sustain one or more falls each year.1 Falls are a leading cause of mortality and morbidity in the elderly.1

The prevalence of obstructive sleep apnea syndrome (OSAS) defined as an apnea-hypopnea index (AHI) of 15 or greater per hour of sleep increases with age and affects about 20% of elderly individuals.2 Excessive daytime sleepiness (EDS), cognitive disturbances, cardiovascular problems, and poor quality of life are major devastating consequences.2 For clinically significant OSAS, continuous positive airway pressure (CPAP) is the most widely established and accepted first-line therapy.

In active middle-aged adults, sleepiness as a result of OSAS has been shown to increase the frequency of occupational3 and motor vehicle accidents.4 In older populations, this may lead to a greater risk of falls and fractures. However, causal relationships between OSAS-related sleepiness and accidental falls in the elderly have not been explored. In addition, the impact of CPAP therapy on falls has not been studied in previous works.

For the first time, we report the clinical features and therapeutic response to CPAP in elderly OSAS patients with sleepiness and falling-asleep–related injured falls.

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Method 

Patients and Acquisition of Data 

Between January 1, 2006, and May 1, 2008, a total of 4 consecutive patients were diagnosed with OSAS and daytime sleepiness–induced fall in 2 geriatric units (Lyon and Paris, France). All subjects had an overnight polysomnography (PSG), underwent Mini-Mental State Examination (MMSE), and completed the Epworth Sleepiness Scale (ESS).5 Treatment effects of CPAP were based on patient self-reports and ESS scores. Treatment compliance was assessed using microprocessor chips that are embedded in CPAP units.

This prospective case series study has been performed in accordance with the Helsinki declaration. An informed consent was obtained from all patients.

Overnight Polysomnography 

Overnight PSG was performed in sleep laboratories. Recorded parameters were at least the following: electroencephalogram (EEG) (C3-A2, C4-A1), electro-oculography (left and right outer cantus), submental electromyogram activity, and electrocardiogram (ECG). Oxyhemoglobin saturation (SaO2) was measured using pulse oxymetry. Oronasal airflow was monitored with thermistors. Thoracic and abdominal respiratory movements were recorded using piezo sensors. Sleep stages were scored according to the international accepted criteria.6 Apnea was defined as cessation of airflow through nose and mouth lasting 10 seconds or more. Hypopnea was defined as a reduction in airflow of 50% or more accompanied by a decline in oxygen saturation (SaO2) of 4% or greater. Oxygen saturation was reported as the average and lowest oxygen saturation. The apnea-hypopnea index (AHI) was defined as the sum of the number of apnea and hypopnea per hour of sleep. An AHI threshold of 15/h or higher was used for the diagnosis of SAS.

The Epworth Sleepiness Scale 

Daytime sleepiness was quantified using the self-administered ESS.5 Scores vary from 0 to 24. Disturbed sleepiness is indicated by scores greater than or equal to 11/24.

Body Mass Index 

Body mass index (BMI) was calculated using height and weight measured in the hospital (kg/m2). Overweight/obese was defined as BMI of 25 or higher.

Mini-Mental State Examination 

Cognitive function was evaluated using the MMSE. MMSE scores from 25 to 30 were judged normal, and the scores below 25 were judged abnormally low.

CPAP Follow-up 

All patients underwent an educational session before commencement of CPAP therapy, which included a one-on-one discussion with a qualified CPAP clinic nurse. CPAP titration was performed in geriatric units with auto-adjusted CPAP devices. Subsequently, during the first year, the subjects were seen in geriatric units at 1 month, 3 months, 6 months, 9 months, and 12 months after starting CPAP therapy. During the second year, 6-month intervals were proposed for clinic visits. Additionally, patients were instructed to contact their durable medical equipment (DME) representative for equipment concerns or problems. Changes in the CPAP setting, nose/face mask, or circuit were made after consultation with the responsible sleep physician if necessary. Objective CPAP compliance measures were obtained either during follow-up geriatric clinic visits or during follow-up home visits made by DME suppliers. Compliance data were accessible via microprocessor chips that are embedded in CPAP units and reflect ‘‘mask on’’ time (the amount of time CPAP was actually used by patients).

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Results 

Clinical data were collected from 4 patients (1 female, 3 males) aged 77 to 85 years old (mean 82 years old) at the time of OSAS diagnosis. All patients shared the following characteristics: self-reported daytime sleepiness, falling-asleep–related injured falls, recurrent fall history (at least 2 falls in the 3 months preceding PSG), medical comorbid conditions (Table 1), and PSG confirmed OSAS (Table 2). All falls occurred without identifiable physical or iatrogenic cause at the time other than falling asleep. All patients were successfully treated with CPAP support during 9- to 24-month periods.

Table 1. Clinical Characteristics of 4 Patients at Initial Observation for Sleep Study
Case, Age, SexSelf-reported “Last” Fall History and Related InjuryComorbid Conditions, Related Treatments, MMSE Scores, BMI, and ESS
1, 78 y, femaleThe most recent fall occurred in the afternoon while she was groggy and walking in her home and caused a left patellar fracture. Since, she has reduced her social activities and refused going to the store and taking public transportation.(1) High blood pressure treated with a thiazide/potassium-sparing diuretic (aldactazine) and a calcium ion antagonist (verapamil chlorhydrate). (2) She had been treated for depression with fluoxetine chlorhydrate for 2 years but treatment had been halted a few months before referral to the geriatric unit and PSG. (3) MMSE 29/30.(4) BMI 27.0 kg/m2. (5) ESS 6/21.
2, 77 y, maleFall in the morning, while he was sitting and sleeping in the rest room. Cranial traumatism, without loss of consciousness but with a minor scalp wound.(1) Both ischemic cardiomyopathy and high blood pressure controlled with amlodipine and furosemide. (2) Benign prostatic hyperplasia treated with tamsulosin hydrochloride. (3) Mild cognitive impairment, MMSE 24/30. (4) BMI 37 kg/m2. (5) ESS 9/21.
3, 84 y, maleFall from his chair, while he was sleeping around 4 pm. Rib fractures. He ceased driving because of EDS and a near-miss accident 2 years ago.(1) Lower limb chronic venous insufficiency treated by elastic compression. (2) bilateral gonarthrosis. (3) MMSE 28/30. (4) BMI 39 kg/m2. (5) ESS 8/18.
4, 85 y, maleFall while he was preparing his bed to take an afternoon nap. Right femoral neck fracture.(1) Benign prostatic enlargement treated with finasteride. (2) Chronic venous insufficiency and history of bilateral leg vein striping. (3) MMSE 26/30. (4) BMI 24.6 kg/m2. (5) ESS 9/21.

BMI, body mass index, kg/m2; EDS, excessive daytime sleepiness; ESS, Epworth Sleepiness Scale; MMSE, Mini-Mental State Examination; PSG, polysomnography.

Table 2. Overnight sleep study, CPAP therapy and ESS results
CaseOvernight Polysomnography FindingsFollow-up, Mean CPAP ObservanceSelf-Reported CPAP Efficiency on Sleepiness and Falls
1OSAS, AHI of 25/h. Mean SaO2 level of 96%, lowest SaO2 level of 90%, time below 90% of SaO2 none.24 months, 6 h/night.Efficient. Resolution of sleepiness and attention deficits, no further fall since the start of CPAP therapy. She has again been taking public transportation for 1 year. ESS 2 to 4/21.
2OSAS, AHI of 70/h. Mean SaO2 level of 91%, lowest SaO2 level of 69%, time below 90% of SaO2 of 36%.12 months, 4 h/nightEfficient. Needs fewer naps (1 to 2 /day) than before. No new fall. ESS 3 to 4/21.
3OSAS, AHI of 27/h. Mean SaO2 level of 92%, lowest SaO2 level of 82%, time below 90% of SaO2 of 3%.12 months, 7.5 h/night.Efficient. Resolution of sleepiness and attention deficits. He has been driving again for 5 months. No further fall since the start of CPAP therapy. ESS 1 to 3/24.
4OSAS, IAH of 40/h.Mean SaO2 level of 90%, lowest SaO2 level of 86%, time below 90% of SaO2 of 33%.9 months, 7 h/nightEfficient. Well rested. Less sleepiness. Improved attention. Better motor and balance control. No new fall under CPAP therapy. ESS 6/21.

OSAS, obstructive sleep apnea syndrome; AHI, apnea–hypopnea index/hour: the number of times in each hour of sleep that subjects have absent or reduced breathing; CPAP, continuous positive airway pressure; ESS, Epworth Sleepiness Scale.

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Discussion 

This prospective study provides new information on the clinical characteristics of both OSAS and falls in the elderly.

First, we report a causal relationship between excessive daytime sleepiness and involuntary falling asleep because of OSAS and injured falls. Thus, OSAS in the elderly should be considered as a potential risk factor for falls. Whereas the risk of an injured fall in the sleep apnea population is increased, not all OSAS patients actually have falls. The following are various well-established fall risk factors: physiological (eg, vision, balance, and muscle strength), iatrogenic (eg, sedative psychotropic drugs), and environmental.1 There is some suggestion that other factors such as nighttime sleep problems7 and daily napping,8 as well as abnormal daytime sleepiness are also associated with an increased risk of falls.9 In previous studies inadequate collection of covariate information such as use of medications, comorbidities, and, particularly, lack of sleep recordings (PSG) make it difficult to confirm the causal relationship between falls and abnormal daytime sleepiness and OSAS in the elderly. Neuropsychological testing has revealed that OSAS patients exhibit a pronounced alteration in daytime vigilance10 and executive cognitive control capacities.11 To a lesser extent, patients with OSAS show impaired memory12 and motor coordination.13 A compounded effect of sleep fragmentation and intermittent nocturnal hypoxemia could explain daytime sleepiness, attention loss, executive dysfunction, and related falls observed in our OSAS patients. In addition, risk of falls and gait disturbances are strongly associated with cognitive impairment and particularly with attention loss and executive dysfunction.14 In recent studies, it has been suggested that gait should be considered as a higher level of cognitive functioning15 because it involves the integration of attention, planning, memory, and other motor, perceptual, and cognitive processes.16 Hypoxemia and fragmented sleep in older apneic patients are related to daytime functional impairments in executive function, attention, vigilance, and motor coordination, which may be likely mechanisms.17

Second, appropriate treatment of OSAS may prevent sleepiness and involuntary falling-asleep–related injured falls. In a meta-analysis performed by Sassini and coworkers18 untreated OSAS was associated with a 2.5-fold increased risk of being involved in a motor vehicle accident. George19 examined the incidence of motor vehicle accidents in a group of 210 patients before and after treatment with CPAP. A group of randomly selected drivers served as the control group. Untreated OSA patients had an accident rate 3 times that of the control group. After CPAP treatment, the accident rate was similar to the control group. In our 4 cases, CPAP therapy considerably improved sleepiness and attention deficits. Cases 1, 2, and 3 were followed for 1 year and more and had no more complaints of somnolence or falling. In case 4, with 9-month follow-up period, complaints of somnolence or falling were also absent since CPAP therapy. Evidence suggests that nightly CPAP use is associated with greater relief of sleepiness (measured with self-reports, ESS, or multiple sleep latency test).20

In conclusion, OSAS with daytime sleepiness may cause severe injured falls. In OSAS, daytime sleepiness, involuntary falling asleep, and falls disappear once patients are treated with CPAP. Subsequent epidemiological studies on sleep apnea and its complications can take into account the relationship between falls and OSAS in the elderly patient in the same way that road accidents and OSAS are linked in younger patients. In routine clinical practice, the potential role of sleep disorders and particularly OSAS in falls should be systematically studied. Geriatricians must consider the diagnosis of sleep apnea when examining elderly patients with a history of injured fall. In elderly fallers with risk factors (eg, obesity) or markers (eg, habitual snoring, daytime sleepiness) for sleep apnea, a careful sleep history should be elicited and a PSG obtained when indicated. Physicians must warn their elderly patients with untreated sleep apnea about the risks of injured falls. Treatment of sleep apnea can improve attention and daytime vigilance and, consequently, gait and balance control and may prevent falls in the elderly.

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References 

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PII: S1525-8610(08)00410-6

doi:10.1016/j.jamda.2008.10.008

JAMDA
Volume 10, Issue 3 , Pages 207-210, March 2009

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