agent causing the casualty, and the general geographic location of the patient at the
time of injury.
f. Item 34, Diagnoses/Operations and Special Procedures.
(1) Recording ICD-9-CM codes. ICD-9-CM coding principles are outlined in
lesson 2. An ICD-9-CM code should be recorded to the left of the diagnosis/operation
entry to which it pertains.
(2) Recording of diagnoses . Record all diagnoses that affect the current,
uninterrupted period of treatment. Record and code unusual manifestations, e.g.,
scarlet fever with acute nephritis. Do not record the admitting or provisional diagnosis.
Do not record diagnoses that relate to earlier admissions, or are status -post conditions,
or physical findings which have no bearing on this period of treatment.
(a) The principal diagnosis is the condition (diagnosis) established after
study to be responsible for the admission of the patient to the hospital. The attending
physician must confirm the principal diagnosis, and it must be substantiated by the
documentation in the medical record.
(b) The primary diagnosis is the condition (diagnosis) which is primarily
responsible for using the greatest amount of hospital resources (it may or may not be
the principal diagnosis).
(c) Comorbidity is a preexisting condition that will cause an increase in
length of stay in approximately 75 percent of cases, because of its presence with a
(d) Complication is a condition arising during the hospital stay that
prolongs the length of stay.
(e) Diagnoses should be numbered consecutively as they are entered on
each Inpatient Treatment Record Cover Sheet. The principal diagnosis will always be
diagnosis number one. Indicate all conditions which are found to have been present
during this period of treatment, even though established after death. Use the notation
"Established Postmortem" as appropriate. List the specific drugs involved in an
(f) Cause of admission. The principal diagnosis, whether as a direct or
transfer admission, should be considered the cause of admission and so recorded. A
patient admitted in respiratory distress (later diagnosed as bronchopneumonia) who
also has hypertension would have bronchopneumonia recorded as the cause of
admission. In cases of several related conditions occurring simultaneously which
require the patient's admission, the condition first in the chain of etiology should be
designated as the cause of admission. For unrelated but simultaneously occurring
conditions requiring admission, the most serious condition will be recorded as the cause
of admission. In instances where two or more diagnoses could be selected due to the