Chapter 102: Differential Diagnosis and Evaluation of Sleepiness

Introduction

Excessive daytime sleepiness (EDS) is a common problem affecting large segments of the general population. Although estimates depend on how sleepiness is defined (i.e., sleeping too much vs. falling asleep in the daytime), about 16% of adults experience sleepiness that affects their daytime function, and there is increasing evidence that sleepiness plays a part in both industrial and road traffic accidents. The National Highway Traffic Safety Administration estimates that more than 100,000 automotive crashes per year are fatigue related. These sleepiness-related accidents contribute to 40,000 injuries and 1550 deaths per year.¹ Over the past two decades, research has provided increased understanding of obstructive sleep apnea (OSA), among other sleep disorders.²

The current prevalence estimates of moderate to severe sleep-disordered breathing with an apnea–hypopnea index, measured as events/h, ≥15 are thought to be higher, with contributing factors such as obesity increasing the prevalence. These estimated prevalence rates represent substantial increases over the last 20 years (relative increases of between 14% and 55% depending on the subgroup). Specifically, the prevalence is 10% (95% confidence interval [CI]: 7, 12) among 30- to 49-year-old men; 17% (95% CI: 15, 21) among 50- to 70-year-old men; 3% (95% CI: 2, 4) among 30- to 49-year-old women; and 9% (95% CI: 7, 11) among 50- to 70-year-old women.³

There is increasing awareness of sleep disorders by the general public and respiratory physicians, by necessity, are dealing more and more with sleep apnea and other sleep disorders. In recognition of the need for training pulmonary physicians in sleep disorders, in 1994 the American Thoracic Society (ATS) published recommendations for training in sleep medicine that has grown to include not only the ATS, but also the AASM, ACCP, AASM,⁴ and ABIM.⁵ There is also significant impact on future training in medicine and surgery based on the sleepiness of the learner. Restriction of duty hours has been reviewed in many countries including ACGME in the US and the RCPSC in Canada. The IOM Report Sleep Supervision and Safety reviewed the potential impact of sleep in training and recommendations made in 2008 were implemented by ACGME including:

The new ACGME standards require residency programs to:

1. Tailor supervision standards for different levels of training, particularly greater supervision for first-year residents.

2. Ensure competence in structured handover processes.

3. Incorporate clinical quality improvement and patient safety into resident learning.

4. Provide safe transportation and/or sleeping facilities for fatigued residents.

5. Adjust workload according to patient severity and resident training.

6. Improve oversight of compliance with duty hour limits.

Specific duty hour recommendations from the IOM include:

1. The maximum number of work hours remains at 80 hours per week, averaged over 4 weeks;

2. Moonlighting, now both internal and external, is counted against the 80-hour weekly limit; and

3. Duty periods are limited to 16 hours (although only for first-year residents by ACGME).

In Canada, ...