Clinical decision making is the process by which we determine who needs what and when. While not exactly arbitrary, this exercise can be quite subjective. Each provider compiles their own data (hence the emphasis on learning to perform an accurate H&P) and then constructs an argument for a particular disease state based on their interpretation of the “facts.” The strength of their case will depend on the way in which they gather and assemble information. There may then be no single, right way of applying diagnostic and therapeutic strategies to a particular case. Medicine involves playing the odds, assessing the relative chance that a patient is/is not suffering from a particular illness. Codifying the way in which providers logically approach problems and deal with this uncertainty is a difficult task. Relying solely on the classic features of a disease may be misleading. That is because the clinical presentation of a disease often varies: the symptoms and signs of many conditions are non-specific initially and may require hours, days, or even months to develop.

Generating a differential diagnosis; that is, developing a list of the possible conditions that might produce a patient’s symptoms and signs, is an important part of clinical reasoning. It enables appropriate testing to rule out possibilities and confirm a final diagnosis.

This case portrays a poor patient outcome after a misdiagnosis.

Case scenario

A previously healthy 35-year-old lawyer presents to a primary care office with a chief complaint of chest pain and a non-productive cough. The pain started suddenly two hours prior to coming to the office while the patient was sitting at his desk. The patient describes the pain as sharp in nature, constantly present but made worse with inspiration and movement, and with radiation to the base of the neck. His blood pressure in the right arm and other vital signs are normal

On physical examination, the only findings of note are chest wall tenderness and a faint cardiac murmur. The ECG in the office is normal. The patient is observed for an hour in the office and assessed. He is diagnosed with viral pleurisy and sent home on non-steroidal analgesics.

The following day the patient collapses at home and cannot be resuscitated by the paramedic service. An autopsy reveals a Type 1 aortic dissection with pericardial tamponade.

Discussion Assignment:

Developing a list of possible conditions that might produce a patient’s symptoms and signs is an important part of clinical reasoning.

As an NP in primary care, what would you have done differently?

Discuss the importance of creating a list of differentials for this patient. How could it have changed this outcome?

If a serious diagnosis comes to mind based on a patient’s symptoms:

Ask yourself: Have you considered the likelihood of a serious diagnosis and whether it needs to be ruled out by testing or referral?
Because many serious disorders are challenging to diagnose, have you considered ruling out the worst-case scenario?
Ask yourself: Do you have a sufficient understanding of the clinical presentation to offer an opinion on the diagnosis?
What other diagnoses could it be? How might the treatment to date have altered the patient’s outcome?
What other diagnostic and laboratory or imaging was needed in order to make a complete differential list? What support tools would you consider using in helping to create a differential diagnosis list?
Are you familiar with the current clinical practice guidelines for the investigation of a suspected condition such as chest pain?