Based on the premise that a well-defined problem is half solved, the primary objective of this Diagnote is to review application
of the DAMN-IT acronym as an aid in formulation of diagnostic plans (a component of the third phase of medical action of the
problem oriented system).
To enhance our ability to detect the underlying cause of various types of illness, we chronologically follow a prioritized
sequence of diagnostic steps (Table 1, Osborne: Veterinary Clinics of North America, Vol. 13, Nov. 1983). To summarize, after
initial identification of the patient's problems (Phase 1- Database) and appropriate refinement of these problems (Phase 2-Problem
List), further diagnostic plans are formulated to confirm and identify the underlying causes of these problems (Phase 3-Initial
problem list). When formulating diagnostic plans, we routinely follow the following sequence of steps: 1) verify or confirm
the presence of problems, especially those defined by clients, 2) localize problems to an organ or body system, 3) consider
the most probable pathophysiologic mechanism(s) associated with the identified problems (DAMN-IT acronym; Table 2), and 4) based on the probable (in contrast to the possible)
pathophysiologic mechanisms present in the patient, formulate specific diagnostic rule-outs (tentative diagnoses) that would explain the underlying cause of the problems, and
implement diagnostic tests to confirm them. By using the DAMN-IT acronym when considering diagnostic rule-outs, numerous diagnostic
can be logically reduced to a few diagnostic probabilities.
Table 1: Four phases of medical action
The DAMN-IT acronym encompasses familiar pathophysiologic disease processes. Therefore, with routine use, it rapidly becomes
part of our memory. When routinely used in conjunction with the history, physical examination and other diagnostic data, the
acronym facilitates rapid and reproducible formulation of probable rule outs (or tentative diagnoses) for each of the patient's
undiagnosed problems. Since I developed the DAMN-IT acronym as an aid to taking examinations when I was a sophomore veterinary
student in 1962, I have added some additional pathophysiologic mechanisms (Table 2). As an iterative memory aid, some of the
pathophysiologic mechanisms listed with different letters in the DAMN-IT acronym overlap (i.e. autoimmune and immune; and
developmental, anomalous, and inherited).
Table 2: DAMN-IT acronym of pathophysiologic causes of disease
What is next?
After developing a list of pathophysiologic mechanisms likely to be causing the clinical problems, the most probable cause(s)
of these problem(s) should be ruled-in or ruled-out by implementing appropriate diagnostic plans. The specific diagnostic
tests and procedures chosen to evaluate each problem, and the rate and frequency with which these tests are implemented, are
dependent on several factors, especially the status of the patient.
If rapidly changing problems are likely to result in irreversible dysfunction or if the problems are an immediate threat
to the patient's life, then diagnostic plans for several rule-outs should be implemented simultaneously (that is, in parallel).
For example, if a critically-ill patient is admitted because of rapidly progressing vomiting, dehydration, impaired urine
concentrating capacity and extreme depression, it is advisable to simultaneously implement diagnostic plans to rule-out renal
failure, diabetic ketoacidosis, hypoadrenocorticism, pyometra and hepatic dysfunction. If an individual priority list of these
rule-outs is established and plans are implemented to rule-out only one cause at a time (that is, in series), then the patient
might die before a specific diagnosis is established.
Diagnoses should not be overstated by guessing their underlying cause based on insufficient evidence. They should be stated
at the level of refinement that can be reasonably justified on the basis of current knowledge about the patient. Why? Because
if the diagnosis is overstated, then misdiagnosis, misprognosis and formulation of ineffective or contraindicated therapy
can result. No patient should be worse for having seen the doctor.