The driver of a car has the general duty to exercise ordinary and reasonable due care in controlling his vehicle so as to avoid colliding with other persons and property (16). Under general negligence principles, a driver's breach of that duty in a manner that proximately causes damages to person or property will be held liable to the injured party (5). However, the law has long recognized that damages caused by a driver's sudden and unforeseen onset of sleep while driving does not constitute negligence (17). The rationale for this "sudden blackout" rule derives, in part, on an examination in 1925 by the Connecticut Supreme Court of early 20th century medical understandings of sleep physiology (18).
The 1925 case of Bushnell v. Bushnell (18) involved an action brought by Mrs. Bushnell against her husband for injuries she sustained when Mr. Bushnell, then 61, fell asleep at the wheel and crashed their car into a tree. The couple was returning home to Connecticut after taking their son to school at Brown College in Providence, Rhode Island. The issue was whether Mr. Bushnell's momentary lapse into sleep constituted negligence on his part.
The Court reasoned that a person under the influence of sleep possess neither sense nor perception. Therefore, the issue of legal responsibility for his conduct could not be resolved by determining whether or not he exercised reasonable care during the period of his unconsciousness. The issue of the driver's legal responsibility instead turned on whether "he exercised such care in permitting himself to lose consciousness in the first instance" (18).
Granted this premise, Mr. Bushnell's lawyer argued that his client could not be charged with negligence because "no man can tell when sleep will fall upon him"
(18). The Court cited contemporary medical literature to dispute the implication that sleep comes about unheralded:
Purves Stewart, in his "Diagnosis of Nervous Diseases," 3rd ed., page 423, thus describes the chief phenomena of ordinary, healthy sleep: "Firstly, there is diminution and then loss of conscious recognition of ordinary stimuli, such as would ordinarily attract our attention, whether these stimuli be derived from the outer world or from within the sleeper's own organism. There is also, as consciousness is becoming blunted, a characteristic and indescribable sense of well-being. Voluntary movements become languid and ultimately cease, and the muscles of the limbs relax. Meanwhile there develops double ptosis or drooping of the eyelids; the pupils contract; the respiratory movements become slower and deeper, the pulse is slowed, the cutaneous vessels dilate to a slight extent and the general temperature of the body falls, whilst many processes of metabolism, such as those of digestion and of certain secretions, are retarded.
Citing the American Journal of Physiology, the Court continued:
Particularly would this be true where the onset of sleep is due to the prolonged action of a uniform excitant, associated with little voluntary movement and a large degree of muscular relaxation, acting upon one who has become more or less fatigued and is sitting down in a warm atmosphere." 66 American Journal of Physiology, pp. 83, 84 (19).
On the basis of this medical evidence, the Court determined that sleep does not ordinarily come about unawares and that a driver retains control either to stay awake or to stop driving (19). As such, the Court ruled that the jury had the right to hear Mr. Bushnell's testimony regarding the unexpected suddenness of his sleep episode.
The ultimate holding in Bushnell not only adopts the "sudden blackout" defense but also points to its limited scope. To benefit from the rule, the loss of consciousness must occur suddenly, without warning, and be unforeseeable (20). As pointed out by the Tennessee Supreme Court, "the key to establishing the physical capacity or loss of consciousness defense is foreseeability" (21).
Thus, depending on the jurisdiction, the defense fails if the driver knew he or she were becoming drowsy or if the driver ignores the treatment regimen prescribed to subdue the symptoms leading to loss of consciousness. Courts differ in the application of the foreseeable rule. Some courts hold that any driver suffering from a medical disorder capable of producing a seizure or unconsciousness is liable, as a matter of law, for driving at all (22). Other courts hold that the sudden blackout defense is inappropriate if the driver was aware of facts sufficient to cause a reasonably prudent person to anticipate that his driving would lead to an accident (21).
Under these principles, knowledge of one's sleep apnea and a propensity for drowsy driving alone will likely be insufficient to invoke the defense. An OSA driver who has been properly warned against sleepy driving and placed on a treatment regimen would very likely have knowledge sufficient to make a sleep episode foreseeable. Thus, much like the diabetic driver who crashed after he skipped lunch and felt hypoglycemic, but neglected to stop and eat (23), the sleepiness of a noncompli-ant CPAP driver with OSA is likely foreseeable, opening the recalcitrant OSA patient to liability for injuries caused by falling asleep at the wheel.
Was this article helpful?