Medical Case Studies

Medical Case examples have been developed by physicians and coders to test your ICD-10 knowledge. In each case study, there will be an example of a patient encounter, information on coding ICD-9 to ICD-10, an eHealth connection and an illustrative comparison of ICD-9 and ICD-10 codes.

Note: These scenarios were natively coded in ICD-10-CM and ICD-9-CM. As patient history and circumstances will vary, these brief scenarios are illustrative in nature and cannot be strictly interpreted or used as documentation and coding guidelines. Each scenario is selectively coded to highlight specific topics; therefore, only a subset of the codes is presented.

Diabetes Mellitus by Marc Leib, MD, JD.

Patient Encounter

A 40-year-old male presents in his physician’s office with complaints of new onset of excessive thirst, urinary frequency and fatigue. His physician ran several tests and based on the results he diagnosed his patient with Type 2 diabetes mellitus. The value of describing patient conditions with ICD-10 codes as compared to ICD-9 codes is made evident when comparing codes available for specific conditions. A common disease affecting millions of patients is diabetes mellitus. According to the American Diabetes Association, “Diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. The chronic hyperglycemia of diabetes is associated with long-term damage, dysfunction, and failure of various organs, especially the eyes, kidneys, nerves, heart, and blood vessels.”

ICD-10 presents many opportunities for the healthcare community

  • Improves the data for peer comparison and utilization benchmarking to reflect patient complexity and level of care provided in support of appropriate reimbursement
  • Enhances information sharing that allow for more specific information to be transmitted between providers

Coding: ICD-9 to ICD-10

In spite of the significant prevalence of this disease, ICD-9 codes describing this condition lack specificity, resulting in the lumping of many patients into broad categories that are not as useful for comparisons and quality measures as ICD-10 codes will be once implemented. Patients with diabetes mellitus are most often described with two ICD-9 codes. ICD-9 codes in the 250xx series describe primary diabetes of all types. Codes in the 249xx group describe secondary diabetes without information regarding the underlying cause of the diabetes. Each series includes a general description of a few complications that may be associated with this disease without detailed descriptions of those complications. These codes lack the specificity necessary to fully document patients’ medical conditions.

The ICD-10 Index includes approximately six pages of specific listings for diabetes and its various clinical manifestations. Almost all of these listings refer to codes in five separate categories of diabetes mellitus, including E08 (Diabetes due to underlying conditions), E09 (Drug or chemical induced diabetes), E10 (Type 1 diabetes), E11 (Type 2 diabetes), and E13 (Other types of diabetes). Notable exceptions to listings in these five code categories are diabetes in pregnancy, including gestational and pre-existing (O24) and neonatal diabetes mellitus (P70.2).

Within the E08 – E13 code categories, there are approximately 200 specific codes that describe diabetes with various associated manifestations or complications, or about 40 codes in each code category. These specific codes are organized into nine code sections under each of the five diabetes code categories describing diabetes with various complications, including ketoacidosis (Exx.1), kidney complications (Exx.2), ophthalmic complications (Exx.3), neurological complications (Exx.4), circulatory complications (Exx.5), other specified complications (Exx.6), unspecified complications (Exx.8) and diabetes without complications (Exx.9). A single ICD-10 code can therefore be used to describe patients with diabetes and its associated complications, if any. An additional code, (Z79.4), identifies patients treated with insulin to control their diabetes.

eHealth Connection

“Use of ICD-10 codes allows clinicians to more accurately describe patients with diabetes mellitus along with associated complications.”
-Marc Leib, MD, JD

Use of ICD-10 codes allows clinicians to more accurately describe patients with diabetes mellitus along with associated complications. This information will be essential for participation in future payment systems that base payments on outcomes or those that require risk adjustments to determine appropriate payment levels. Information in ICD-10 codes will be used to determine payments in these future payment systems, making it essential that providers utilize these codes correctly.

Comparison of Current ICD-9 Code and Illustrative ICD-10 Codes

ICD-9-CM
250.42 Diabetes with renal manifestations, type 2, not stated as uncontrolled
585.1 – 585.6 Various stages of chronic renal disease
250.62 Diabetes with neurological manifestations, type 2, not stated as uncontrolled
357.2 Polyneuropathy in diabetes
V45.11 Renal dialysis status
ICD-10-CM
Correct Code:
E11.22Type 2 diabetes mellitus with diabetic chronic kidney disease
Other Illustrative ICD-10 Codes That Map to the Current ICD-9 Code:
N18.1 – N18.6 Various stages of chronic renal disease
Z99.2 Dependence on renal dialysis
Presence of AV shunt for dialysis
E11.42 Type 2 diabetes mellitus with polyneuropathy

Capturing Fractures in ICD-10: Location is Key For Treatment

Patient Encounter

A 26 year old female presented to the emergency department following a motor vehicle crash. She sustained minor soft tissue injuries and had a complicated right hand injury, which was swollen, painful, and deformed. After evaluating the patient and viewing the radiology results, Dr. Martinez diagnosed a displaced mid-shaft spiral fracture of the fourth metacarpal and documented the encounter in the hospital’s electronic medical record. This particular injury required orthopedic consultation for appropriate therapy and follow up.

ICD-10 presents many opportunities for the healthcare community

  • Improves diagnosis of injuries and identifies underlying causes, complications, and conditions that contribute to the complexity of a case.
  • Enhances information sharing that allow for more specific information to be transmitted between providers

Coding: ICD-9 to ICD-10

In ICD-9-CM, the current coding system, the best diagnosis code for this injury is 815.03, Closed fracture of shaft of metacarpal bone(s). The ICD-9 code limits the information gained from the diagnostic evaluation. This same hand injury coded in ICD-10-CM provides much more detail about the injury using diagnosis code S62.324A, Displaced fracture of shaft of the fourth metacarpal bone, right hand, initial encounter for closed fracture.

eHealth Connection

“Medicine is a team effort. Patients move between specialists and generalists. The ability to communicate clearly has always been important, but our codes have not caught up with how physicians speak to each other. Now they have.”
-Ricardo Martinez, MD, FACEP

The difference in these two codes is apparent—ICD-10 incorporates laterality, the specific bone involved, type, pattern, encounter of care, and displacement, while ICD-9 code does not. ICD-10 provides a new distinction for fractures that ICD-9 cannot provide.

The ability to communicate with other care providers is especially important to an emergency physician, as many of Dr. Martinez’s patients are eventually referred to another provider for continued care. ICD-10 affords a common language that helps facilitate transitions of care and interpretation by a receiving provider. Every character and digit in the ICD-10 nomenclature has an implication.

Comparison of Current ICD-9 Code and Illustrative ICD-10 Codes

ICD-9-CM
815.03 Closed fracture of shaft of metacarpal bone(s)
ICD-10-CM
Correct Code:
S62.324A Displaced fracture of shaft of the fourth metacarpal bone, right hand, initial encounter for closed fracture
Other Illustrative ICD-10 Codes That Map to the Current ICD-9 Code:
S62.354A Non-displaced fracture of shaft of fourth metacarpal bone, right hand, initial encounter for closed fracture
S62.326A Displaced fracture of shaft of the fifth metacarpal bone, right hand, initial encounter for closed fracture
S62.325A Displaced fracture of shaft of the fourth metacarpal bone, left hand, initial encounter for closed fracture

Cardiology by Mark Bieniarz, MD

Patient Encounter

A 53 year old male presents with one week of progressive chest pain with exercise. Over the last two hours prior to presentation, he developed severe worsening of his pain with radiation to the jaw and left wrist while at rest accompanied by nausea and diaphoresis. His cardiovascular risk factors include long history of smoking (1 pack per day), type 2 diabetes (on insulin), hypertension (poorly controlled), and hyperlipidemia (not on statin because he doesn’t believe in them). He has a significant family history (his brother, age 55, and his father, age 60, both suffered myocardial infarctions). On exam, he is: uncomfortable and diaphoretic with elevated jugular veins, no carotid bruit, rales heard halfway up lung fields, tachycardia with + S3, no murmurs, abdomen soft and non-tender, and a trace pedal edema. His ECG demonstrates ST elevation in V1-V5 of 4mm with reciprocal ST depression in the inferior leads and sinus tachycardia. He is taken to the Cath Lab emergently for primary percutaneous coronary intervention (PCI) with 75% lesion to the LAD. Acute Anterior MI and Angina.

ICD-10 presents many opportunities for the healthcare community

  • Improves the data for peer comparison and utilization benchmarking to reflect patient complexity and level of care provided in support of appropriate reimbursement
  • Enhances information sharing that allow for more specific information to be transmitted between providers

Coding: ICD-9 to ICD-10

ICD-10-CM offers a clear upgrade in capturing Myocardial Infarctions.

  1. Acute MI’s are now coded only for the first 4 weeks from onset.
  2. Additional MI category for a subsequent MI within the 4 weeks of the previous MI.
  3. Coding should include capturing the underlying disease process that contributed to the MI such as ASHD along with any current angina or spasm. ASHD has separate categories for native coronary artery, or autologous or non-autologous bypass grafts.
  4. Any tobacco use/dependence or exposure to tobacco is coded as an additional code.

eHealth Connection

“It is very important to have the severity and/or etiology of diseases we are managing accurately portrayed.”
-Mark Bienarz,MD

Use of ICD-10 codes allows clinicians to more accurately describe patients with myocardial infarctions directly to the coronary vessel(s) affected along with the underlying disease process. This information will be essential for participation in future payment systems that base payments on outcomes or those that require risk adjustments to determine appropriate payment levels. Information in ICD-10 codes will be used to determine payments in these future payment systems, making it essential that providers utilize these codes correctly.

Comparison of Current ICD-9 Code and Illustrative ICD-10 Codes

ICD-9-CM ICD-10-CM
410.11 Acute Myocardial infarction of other anterior wall, initial episode of care I21.02 ST elevation (STEMI) myocardial infarction involving left anterior descending coronary artery
414.01 Coronary atherosclerosis of native coronary artery I25.119 Atherosclerotic heart disease of native coronary artery with unspecified angina pectoris
413.9 Other and unspecified angina pectoris Z72.0 Tobacco use
V15.82 Personal history of tobacco use
250.00 Diabetes mellitus without mention of complication, type II or unspecified type, not stated as uncontrolled E11.9 Type 2 diabetes mellitus without complications
V58.67 Long term (current) use of insulin Z79.4 Long term (current) use of insulin
401.9 Unspecified essential hypertension I10 Essential (primary) hypertension
272.4 Other and unspecified hyperlipidemia E78.5 Hyperlipidemia, unspecified
V17.3 Family history of ischemic heart disease Z82.49 Family history ischemic heart disease and other diseases of the circulatory system

Diabetes Complicating Pregnancy: Reflecting Additional Specificity in Gestational Diabetes Through ICD-10

Patient Encounter

A 33-year old G2P1 female presented for her routine prenatal visit at 30 weeks gestation to see her obstetrician. With this pregnancy, her first prenatal visit was at 20 weeks and she has sporadically kept her appointments up to this visit. To note, her previous pregnancy two years ago was an uncomplicated vaginal delivery at 38 weeks gestation. The baby weighed 4.2kg at delivery and was complicated by shoulder dystocia. She had minimal general medical care between the pregnancies.

At the patient’s 28 week visit, her prenatal surveillance included an abnormal 1-hr glucose challenge test. She returned for a follow up 3-hr OGTT, which revealed abnormal findings; these results were shared with the patient at the 30 week visit. Upon questioning, the patient admitted that there is a family history of diabetes in several of her relatives; however, she has never been tested for diabetes. The patient’s evaluation also demonstrated a body mass index (BMI) of 34, BP 130/78 and fetal heart tones at 148 BPM.

Based on these results, the obstetrician diagnosed the patient with gestational diabetes mellitus (GDM) and established a plan of care for the duration of her pregnancy. This plan of care included nutritional counseling with monitoring of her blood glucose as well as possible medical intervention, if glycemic control could not be established. Additionally, the plan called for increased antenatal surveillance based on glycemic control

ICD-10 presents many opportunities for the healthcare community

  • Improves the data for peer comparison and utilization benchmarking to reflect patient complexity and level of care provided in support of appropriate reimbursement
  • Enhances information sharing that allow for more specific information to be transmitted between providers
  • Provides robust detail for research and data analysis

Coding: ICD-9 to ICD-10

In ICD-9-CM, gestational diabetes mellitus codes to 648.83, Abnormal glucose tolerance of mother, antepartum condition or complication. In ICD-10, this condition maps to code O24.410, Gestational diabetes mellitus in pregnancy, diet controlled. Note the change in terminology between ICD-9 and ICD-10 describing the specification of Gestational diabetes mellitus. Additional ICD-10 parameters for gestational diabetes also include the control mechanism as either insulin or diet. Should the status of the patient’s gestational diabetes change during the course of her pregnancy or in the post-partum period, it can be reflected by the choice of code, as referenced in the “Comparison of Current ICD-9 Code and Illustrative ICD-10 Codes” table below.

It is also important to note that if the patient had been diagnosed with diabetes prior to her pregnancy, there are codes now available in ICD-10 to indicate the pre-existing condition and the current trimester. Similar to the general classification for diabetes mellitus, the codes include classifications type 1 and type 2 diabetes and similar to gestational diabetes mellitus, the codes include the classifications for “in childbirth” and “in the puerperium”.

eHealth Connection

The ability of ICD-10-CM to capture more data in terms of depth and specificity helps providers to recognize differences in the risk, severity, and complexity of each case. This is of particular importance as our healthcare system moves towards value based healthcare. Better identification and documentation of the complexity of a patient’s condition enables greater data collection of the specific care rendered to a patient. From this data comes the ability to demonstrate the true value of the care physicians provide to their patient populations.

Comparison of Current ICD-9 Code and Illustrative ICD-10 Codes

ICD-9-CM
648.83 Abnormal glucose tolerance, antepartum condition or complication
ICD-10-CM
Correct Code:
O24.410 Gestational diabetes mellitus in pregnancy, diet controlled
Other Illustrative ICD-10 Codes That Map to the Current ICD-9 Code:
O24.414 Gestational diabetes mellitus in pregnancy, insulin controlled
O24.420 Gestational diabetes mellitus in childbirth, diet controlled
O24.424 Gestational diabetes mellitus in childbirth, insulin controlled
O24.434 Gestational diabetes mellitus in the puerperium, insulin controlled
O24.011 Pre-existing diabetes mellitus, type 1, in pregnancy, first trimester
O24.012 Pre-existing diabetes mellitus, type 1, in pregnancy, second trimester
O24.013 Pre-existing diabetes mellitus, type 1, in pregnancy, third trimester
O24.02 Pre-existing diabetes mellitus, type 1, in childbirth
O24.03 Pre-existing diabetes mellitus, type 1, in the puerperium
O24.111 Pre-existing diabetes mellitus, type 2, in pregnancy, first trimester
O24.112 Pre-existing diabetes mellitus, type 2, in pregnancy, second trimester
O24.113 Pre-existing diabetes mellitus, type 2, in pregnancy, third trimester
O24.12 Pre-existing diabetes mellitus, type 2, in childbirth
O24.13 Pre-existing diabetes mellitus, type 2, in the puerperium

Documenting Dermatological Details With ICD-10

Patient Encounter

A solo Family Medicine physician received a telephone call from the mother of a 15 year old female patient in general good health regarding a new pruritic rash on her hands, arms, and legs, which had started 5 days earlier and was described as “hives.” During the call, the Family Medicine physician advised the patient to take OTC cetirizine daily, ranitidine daily, and diphenhydramine, as needed, nightly. The patient denied any contact with new chemicals, cosmetics, plants, insects, or food. She also denied any past history of similar rashes, asthma, atopy, or eczema. No other members of the patient’s family experienced symptoms.

Two days later, after no improvement, the Family Medicine Physician saw the patient in her office. Upon physical examination, the patient still had a pruritic, erythematous, papular rash located on the flexural areas of both wrists and elbows as well as behind her knees. The physician prescribed triamcinolone acetonide cream, 1%, and advised the patient to apply it 2-3 times a day for a maximum of 14 days, in addition to using a moisturizing cream. The patient’s atopic dermatitis resolved completely after just one week. The physician’s final diagnosis for this case would be coded in ICD-9 as atopic dermatitis.

ICD-10 presents many opportunities for the healthcare community

  • Improves the data for peer comparison and utilization benchmarking to reflect patient complexity and level of care provided in support of appropriate reimbursement
  • Enhances information sharing that allow for more specific information to be transmitted between providers

Coding: ICD-9 to ICD-10

In ICD-9-CM, the patient’s condition currently maps to 691.8, Other atopic dermatitis and related conditions, a more general code that includes related conditions like eczema (atopic, flexural, and intrinsic), Besnier’s, and neurodermatitis. In ICD-10-CM, this patient’s condition maps to the specific different types, and in this patient, it would be code L20.82, Flexural eczema. Greater specificity is afforded in ICD-10, where the code specifically indicates eczema, the type of eczema, and will allow the physician to capture and communicate greater detail about this patient’s exact condition. ICD-10 provides specific codes for each of the conditions that are currently captured in the general ICD-9 code as illustrated in the table below.

Overall, in ICD-9-CM, many dermatologic conditions and commonly seen rashes are lumped into a few, broad diagnosis codes. ICD-10 will enable providers to perform more targeted case studies and reviews, and improve overall quality of care.

eHealth Connection

The ability of ICD-10-CM to capture more data in terms of depth and specificity helps providers to recognize differences in the risk, severity, and complexity of each case. This is of particular importance as our healthcare system moves towards value based healthcare. Better identification and documentation of the complexity of a patient’s condition enables greater data collection of the specific care rendered to a patient. From this data comes the ability to demonstrate the true value of the care physicians provide to their patient populations.

Comparison of Current ICD-9 Code and Illustrative ICD-10 Codes

ICD-9-CM ICD-10-CM
691.8 Atopic dermatitis Correct Code:
L20.82 Flexural eczema
Other Illustrative ICD-10 Codes That Map to the Current ICD-9 Code:
L20.0 Besnier’s prurigo
L20.81 Atopic neurodermatitis
L20.84 Intrinsic (allergic) eczema
L20.89 Other atopic dermatitis
L20.9 Atopic dermatitis, unspecified