# A 57-year-old taxi driver who keeps dozing off: a sleepiness case to work up

> A respiratory case for medical students: a 57-year-old taxi driver who keeps nodding off and has fallen asleep at the wheel. What to ask, red flags, examination, first tests and the differential.

- Respiratory Medicine · Beginner · about 15 minutes
- Web page: https://www.medikarya.in/case-studies/57-year-old-taxi-driver-who-keeps-dozing-off
- Work up this patient: https://www.medikarya.in/case-studies/57-year-old-taxi-driver-who-keeps-dozing-off

## How the patient presents

A 57-year-old taxi driver has been nodding off whenever he sits quietly for two years. He has twice fallen asleep at the wheel. He gets a full eight hours in bed every night.

## Why daytime sleepiness matters

Excessive daytime sleepiness is easy to dismiss as tiredness, but it has treatable causes and real dangers, especially for someone who drives for a living. The history, ideally with a bed partner's account, usually points the way.

## What to ask in the history

- How sleepy, and in which situations (a sleepiness scale helps)
- Hours in bed, sleep timing, shift work
- Snoring, pauses in breathing seen by a partner, waking choking, morning headaches, passing urine at night
- Weight change
- Alcohol, sedatives
- Mood
- Symptoms of an underactive thyroid
- Blood pressure, diabetes, heart disease
- Near-misses or accidents while driving

## Red flags

- Falling asleep while driving
- Breathlessness, ankle swelling
- Low mood with thoughts of self-harm

## What to examine

- Weight, body mass index, neck circumference
- Blood pressure
- Nose, mouth, tonsils and jaw
- Thyroid
- Heart and lungs; ankle swelling

## First investigations

- A sleep study: overnight oximetry or polysomnography
- Thyroid function
- Glucose or HbA1c, cholesterol
- Full blood count
- Blood gas if he may be under-breathing

## Differential diagnosis of daytime sleepiness

Grouped, not ranked. Which one fits this patient is for you to work out in the case.

### Medical

- Hypothyroidism
- Depression
- Alcohol or sedatives
- Diabetes

### Too little or poor sleep

- Shift work
- Insufficient sleep
- Insomnia

### Breathing in sleep

- Obstructive sleep apnoea
- Obesity hypoventilation

### Primary sleep disorders

- Narcolepsy

## Common mistakes

- Not asking about driving, and not advising him about it.
- Taking eight hours in bed as eight hours of good sleep.
- Leaving out the partner's account.

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A study guide for medical students, not medical advice. Follow your institution's protocols in practice.