Some respiratory diseases may, if severe enough, interfere with the safe operation of a motor vehicle. A decrease in the provision of oxygen to the brain could impair judgment, reduce concentration, and slow response times (Karakontaki et al., 2013) . Marked dyspnea may also limit a person’s physical ability to operate a motor vehicle. It is important to note that suboptimal oxygenation could destabilize respiratory illness and impair cognition (Parekh et al., 2005) , and the resulting insufficient cerebral oxygenation could compromise driver fitness (Karakontaki et al., 2013; Skovhus Prior et al., 2015) . Advanced respiratory disease, as well as morbid obesity, may lead to decreased ventilation, and the resulting hypercapnia could lead to psychomotor symptoms that may affect fitness to drive (Bahammam and Al-Jawder, 2012) . Furthermore, older age and physical decline from respiratory disease may affect a person’s functional ability to drive (Colón-Emeric et al., 2013) .
Section 18
Respiratory diseases
Alert
Immediate contraindication to driving — a patient with the following type of problem should be advised not to drive until the condition has been evaluated and has been treated or has resolved:
- any condition resulting in insufficient cerebral oxygenation or hypercapnia causing psychomotor slowness; for example, symptomatic decompensated chronic obstructive pulmonary disease.
18.1 Overview
18.2 Assessment
Impairment associated with dyspnea can be characterized as follows:
- Mild — Dyspnea when walking quickly on level ground or when walking uphill; ability to keep pace with people of the same age and body build when walking on level ground, but not on hills or stairs.
- Moderate — Shortness of breath when walking for a few minutes or after 100 m of walking on level ground.
- Severe — Too breathless to leave the house; breathless when dressing; presence of untreated respiratory failure.
18.3 Chronic obstructive pulmonary disease and other chronic respiratory diseases
Driving could be dangerous for a patient with untreated chronic hypoxia. Many patients with chronic respiratory diseases, such as chronic obstructive pulmonary disease (COPD), drive safely and regularly, even when oxygen use is required. It is important to recognize that driving performance cannot be determined solely by disease severity; a focus on functional abilities is also needed (Orth et al., 2008). A driving assessment, road test, or both are recommended if the physician has any doubt about the patient’s ability to operate a motor vehicle. Oxygen equipment, if used, must be safely secured in the vehicle. Refer to Table 12 for recommendations for patients with chronic respiratory disease, summarized from the Canadian National Safety Code (Canadian Council of Motor Transport Administrators, 2021).
| Level of impairment* | Non-commercial driving | Commercial driving |
|---|---|---|
| None or mild | No restrictions | No restrictions |
| Moderate | No restrictions The level of impairment should be reassessed periodically to ensure no progression of disease, which might affect the individual’s functional ability to drive. | Depends on the nature of the activities. On-road testing may be required. Health care provider will need to address the following:
|
| Moderate or severe, with use of supplemental oxygen at rest | Road test, while using supplemental oxygen, to ensure appropriate functional ability. Oxygen equipment must be secured safely and used while driving. Routine clinical re-assessment is required. | Not eligible for a licence. Severe impairment or the need for continuous supplemental oxygen signifies difficulties with the level of functional performance that would be deemed necessary for commercial driving. |
| *Level of impairment can be characterized on the basis of respiratory symptoms or pulmonary function testing. The relationship between respiratory symptoms and pulmonary function is not perfect, so a focus on the individual’s symptoms and functional abilities should be prioritized. | ||
18.4 Permanent tracheostomy
A person with a permanent tracheostomy who has no difficulty keeping the opening clear of mucus should be able to drive any class of motor vehicle, provided that the medical condition making the tracheostomy necessary does not preclude driving. See also Section 25, Motorcycles and off-road vehicles.
References
Bahammam AS, Al-Jawder SE. Managing acute respiratory decompensation in the morbidly obese. Respirology. 2012;17(5):759-71.
Canadian Council of Motor Transport Administrators. Chapter 16: Respiratory diseases. In: National Safety Code. Standard 6. Determining driver fitness in Canada. Part 2: CCMTA medical standards for drivers. Ottawa (ON): The Council; 2021. p. 201-7. Available: https://ccmta.ca/web/default/files/PDF/National%20Safety%20Code%20Stand… (accessed 2022 Oct. 23).
Colón-Emeric CS, Whitson HE, Pavon J, Hoenig H. Functional decline in older adults. Am Fam Physician. 2013;88(6):388-94.
Karakontaki F, Gennimata SA, Palamidas AF, Anagnostakos T, Kosmas EN, Stalikas A, et al. Driving-related neuropsychological performance in stable COPD patients. Pulm Med. 2013;2013:297371.
Orth M, Diekmann C, Suchan B, Duchna HW, Widdig W, Schultze-Werninghaus G, et al. Driving performance in patients with chronic obstructive lung disease. J Physiol Pharmacol. 2008;59 Suppl 6:539-47.
Parekh PI, Blumenthal JA, Babyak MA, LaCaille R, Rowe S, Dancel L, et al. Gas exchange and exercise capacity affect neurocognitive performance in patients with lung disease. Psychosom Med. 2005;67(3):425-32.
Skovhus Prior T, Troelsen T, Hilberg O. Driving performance in patients with chronic obstructive lung disease, interstitial lung disease and healthy controls: a crossover intervention study. BMJ Open Respir Res. 2015;2:e000092.