82-year-old female with pneumonia: case study guide

The first question is the one where a current textbook and an older one give different answers, and the case is built to expose that. ND lives in a skilled nursing facility, and the category most study material still attaches to that fact no longer exists in the guidelines.

Healthcare-associated pneumonia was introduced in 2005 to flag patients whose contact with healthcare made resistant organisms likelier — nursing home residents among them — and it was withdrawn in the 2016 guidance because it did not work. The category turned out to be neither sensitive nor specific for identifying resistant organisms, and using it drove broad-spectrum antibiotics into patients who did not need them. So an answer that classifies ND's pneumonia as healthcare-associated because of where she lives is repeating a retired category. The current framing treats her as community-acquired, arriving from outside hospital, with her individual risk factors for resistance assessed on their own rather than inferred from her address. Saying that, and saying why the category was dropped, is a better answer than the label. The distinction is not academic: it is the difference between reaching for broad-spectrum cover on the basis of an address and choosing therapy from what this patient actually carries.

The question also says pneumonia can be classified many different ways, which is an invitation to use more than one axis. Setting of acquisition is one. Mechanism is another, and on that axis aspiration is live: she is wheelchair bound, spends most of her days in bed, and has spent three days refusing to eat or drink. Anatomy is a third, and the case supplies it — diminished sounds and crackles localised to the right middle lobe describe a lobar distribution rather than a diffuse one, which itself points toward a typical bacterial process rather than an atypical or viral one. Working two or three axes and saying what each contributes is a fuller answer than choosing one label and defending it. The question's own wording gives permission for this, so taking it costs nothing and demonstrates more than a single label does.

The second question has a planted answer. Rust-coloured sputum is the classical description associated with pneumococcal infection, and the case writer changed her sputum from white and yellow to rust-coloured specifically at the point she deteriorated. Combined with the lobar findings and the abrupt onset of fever and confusion, Streptococcus pneumoniae is the expected answer and should be given with the reasoning attached rather than as a guess. It is worth adding what else is plausible in an eighty-two-year-old with chronic bronchitis — Haemophilus influenzae, Moraxella catarrhalis — and, if you argued aspiration on the mechanism axis, the oral anaerobes and Gram-negative organisms that go with it. Naming the alternatives also protects the answer, since a single organism asserted with no hedge reads as recall rather than reasoning, and her chronic bronchitis genuinely widens the field.

The third question is where severity belongs, because tests are chosen partly to establish how sick someone is. Chest radiography is the one that makes the diagnosis, since pneumonia is a clinical picture plus an infiltrate. Beyond that: blood cultures and sputum Gram stain and culture before antibiotics, a full blood count with differential, renal function and electrolytes, lactate, pulse oximetry or arterial blood gas, and pneumococcal and Legionella urinary antigens. Then apply a severity score rather than describing her as unwell — she is confused, over sixty-five, and her systolic pressure is 86, which is three of the five components of the common bedside score before urea is even measured, and her respiratory rate of 28 sits just under the fourth. Scoring her puts the admission decision on record as a conclusion rather than as something the vignette already told you.

One thing the case includes that the three questions do not ask about is worth a sentence anyway: fifty-two pack-years of smoking, ten pounds lost in a month, and a productive cough for two weeks in an eighty-two-year-old. Pneumonia explains the last three days. It does not explain the month before them, and a lesion obstructing a bronchus produces exactly this picture — recurrent or non-resolving consolidation in one lobe. Noting that the radiograph should be followed to resolution, and why, costs two lines and shows the case was read as a patient rather than as a question set. Follow-up imaging after treatment is the concrete recommendation, and it is the kind of line that separates a clinical answer from a correct one.