Duty of care is defined in different ways depending on the specific circumstances involved in any one case, according to precedents set in various tort cases. In one of the most famous of these cases, Donoghue v Stevenson  UKHL 100, Lord Atkin set out the principle that all members of society owe a duty of care to their "neighbors" -- anyone who might be reasonably be affected by any action taken or omitted -- to avoid causing them injury. In Bolam v Friern Hospital Management Committee  1 WLR 582, it was determined that doctors -- and by extension other individuals in skilled professionals, with professed expertise and greater-than-average knowledge and/or skill -- have an extra duty of care to maintain actions that are in accordance with the standard and reasonable practices of that profession. Simply put, "duty of care" refers to the care an individual needs to take to not injure another person, and the level and specifics of this duty change with each situation.
Given the above definition of a duty of care, a breach of duty exists whenever injury is caused that could have reasonably been foreseen and prevented by refraining from taking the injurious act (or by taking an act that is necessary to prevent injury). In the case of Donoghue v Stevenson, a breach of duty was determined to exist because a ginger beer manufacturer, Mr. Stevenson, had failed to secure the safety of his product and a consumer, Mrs. Donoghue, had become ill after drinking a bottle of ginger beer that proved to contain a snail. In Bolam, on the other hand, the fact that the patient had been treated in a manner in keeping with standard practiced of the medical profession meant that the hospital had not breached its duty of care.
Damages, in a tort case, are a measure of the injury that has been suffered by the victim of negligence or a breach of duty. Real injury must have occurred for any award of damages to occur, and it is possible for a breach of duty to occur without damage -- had Mrs. Donoghue not taken ill after her ginger beer, for instance, Mr. Stevenson's breach of duty would have been no less serious but the damage would have been much less substantial if not non-existent. In Bourhill v Young  AC 92, in which Mrs. Bourhill was witness to the aftermath of a motorcycle accident caused by Mr. Young, it was decided that no duty of care had extended to this witness and thus damages could not attach: Young was negligent to others in his act but not to Mrs. Bourhill, that is, and thus even if she suffered harm as a result of what she witnessed (a debatable matter of fact that the court did not take up), no damages would have been awarded. In Caparo Industries plc v Dickman  UKHL 2, a three prong test of being fair, just, and reasonable to impose a liability and award damages was also developed and applied to cases of negligence, as well.
In Jenny's case, the tests developed in the above-described cases and the malleable yet working definitions of duty of care, breach of duty, and damages can be used to show that Jenny would likely be successful in a tort case brought against the hospital, though several findings of fact would need to be made before a certain conclusion could be made. The first step in determining if Jenny was treated with negligence and if she should be awarded any damages, of course, is determining whether or not the hospital (in the form of its personnel) owed her any duty of care. As with Bolam, the hospital's duty of care would extend beyond the "good neighbor" principle established in Donoghue v. Stevenson, as the doctors and nurses caring for Jenny would be expected to act in accordance with the standards of their profession.
This is one area where a finding of fact would be necessary, as the case as presented is not complete enough to determine what the standards of the profession are or whether or not they were met in the care that Jenny was provided. The mention that the hospital was understaffed and that the medical team had "failed to notice" a blocked artery in Jenny's leg definitely implies that their actions were not in keeping with expectations of the profession and of handling a patient in Jenny's condition and with her specific problems. If this is indeed the case, then the duty of care the hospital had towards Jenny was breached by the failure to notice her blocked artery -- the hospital/staff failed to live up to the standard and reasonable actions expected of their skilled and knowledgeable profession. Jenny was treated negligently, regardless of any extenuating circumstance the hospital might plead (i.e. that it is understaffed), and this breach of duty makes a seeking of damages not only a natural outcome for Jenny but also a course of action that is likely to be successful.
The loss of Jenny's leg was certainly injurious, and thus the hospital cannot claim that Jenny was not damaged by its breach of duty/negligence: she was damaged by their failure to act in accordance with the standards of their profession, and deserves to be made whole. The remaining question is whether it is fair, just, and reasonable to impose a liability. From Jenny's perspective it is certainly all of these things; she is without one of her legs as a result of the hospital's negligence, and it would certainly be fair and just for restitution to be paid while it is more than reasonable to ask the hospital to pay it. It could be argued, however, that awarding damages opens the hospital to unreasonable liability that would hamper its ability to effectively treat patients; again, the medical facts of the case would need to be known in greater detail and likely debated before a concrete decision could be made in this regard.
In a negligence claim, damages are meant to make someone whole -- to restore them to their position prior to the incident of negligence/injury. Victims are not meant to profit, exactly, from the breach of duty that led to their injury; tort cases are not meant to be a means of earning a living or even of being bettered by having a misfortune (caused by breach of duty) befall oneself. Tort cases, like courts generally, are a tool to be used in most cases to preserve or restore the status quo -- to make sure things turn out fairly, which means if one party injures another through negligence/a breach of duty, the injuring party must "undo" the injury insofar as possible. Again, the duty of care that one party has for another varies depending on the specific circumstances of each case, including the declaration (explicit or implicit) of special knowledge or skill, which creates a special duty of care as in medical situations and in other cases where a matter of certain expertise is to hand, and this affects when an injuring party actually takes on liability for damages. This is also part of the fairness contract; everyone is responsible for preventing injury to those around them so long as "those around them" is defined with an eye towards proximity and that the injuries caused were reasonably foreseeable, and damages will not be awarded in cases where this proximity or foreseeability are not applicable -- it is not the acting party's responsibility to make non-proximal or unforeseeable injuries whole.
The first principle of damages, then, is that they are used as a remedy when one is at fault for an injury, and are essentially paid by the party at fault as compensation for that injury. They are not, in tort cases involving negligence or a breach of duty, awarded for punitive means and again they are not meant to be a boon to the victim of the negligence/breach of duty and the injured party; they are meant to make this injured party whole, to compensate them for being injured. In cases where negligence led to direct monetary damages this principle is quite clear and usually applied with relative ease. Such damages are called pecuniary damages -- damages that can be calculated based on direct injury to property, income, and other quantifiable elements of the victim's life. Medical expenses would be one source of pecuniary damages awarded in a case of medical negligence; if the victim of a breach of duty by a doctor incurs direct medical expenses (required to outfit their home with walking aids or support, perhaps, or required to pay for physical therapy or training) as a result of the doctor's negligence, that doctor would likely be required to pay pecuniary damages that allowed the victim to recoup the cost of these expenses. Again, it is not simply…