Pulmonary fibrosis is a progressive lung disease, it is a long term disease that affects the lung

tissue by scarring or thickening of the lung tissue resulting to stiffness, loss of elasticity and loss

of gas exchange. This is an irreversible process in which lung capacity is gradually decreased

causing shortness of breath and persistent cough with progressive respiratory deficiency.

Pulmonary fibrosis is not a disease, rather a pattern of damage to the lung induced by a wide

variety of underlying diseases including autoimmune diseases, occupational, or idiopathic

(unidentified).

To diagnose pulmonary fibrosis properly and specifically and to classify it accurately are critical

to both clinical and administrative applications. The International Classification of Diseases,

Tenth Revision (ICD-10) is one of the primary systems employed in the classification process all

over the world. The coding system assists clinicians, hospitals and insurance providers to record

and track the diseases accurately to be used in reporting, billing and epidemiology.

Pulmonary fibrosis is mostly classified in the ICD-10 chapter in Diseases of the respiratory

system (J00-J99). In this chapter, the fibrotic interstitial lung diseases are included under the

J84 – Other interstitial pulmonary diseases. This category comprises a number of conditions

where there are scarring and thickening of the lung interstitium. As pulmonary fibrosis has

various causes the accuracy of the coding is dependent upon the specification of the idiopathic,

secondary or external factors causing the disease such as radiation or drug exposure.

Primary ICD-10 Codes of Pulmonary Fibrosis.

● The following are the ICD-10 codes that are commonly used in regards to pulmonary

fibrosis:

● J84.10 – Pulmonary fibrosis, not specific for this.

● Applied when the medical record merely states pulmonary fibrosis, but not the cause of

the pulmonary fibrosis or its type.

● J84.11 Idiopathic interstitial pneumonia.

● And in such includes idiopathic interstitial lung diseases of indeterminate provenance.

● J84.112 Idiopathic pulmonary fibrosis (IPF).

● The most precise and specific Idiopathic pulmonary fibrosis is the most prevalent form of

idiopathic interstitial pneumonia.

➔ Other interstitial pulmonary diseases with fibrosis in non-laboratory disease.

Applied in cases of fibrosis being a symptom of some other systemic disease, e.g., rheumatoid

arthritis or scleroderma.

● J70.1 – radiation chronic and other pulmonary manifestations.

● Applied when pulmonary fibrosis occurs as a radiation therapy side effect of the chest.

● In short, J84.10 is quite a general code, whereas J84.112 is much more specific to the

Idiopathic Pulmonary Fibrosis (IPF), which has its own diagnostic and treatment

implications.

Coding Guidelines and considerations.

● Medical coders have to consider the following when coding pulmonary fibrosis:● Documentation Detail – The underlying cause should always be documented or

whether it is idiopathic or not.

● Exclusion Notes – It is necessary to exclude J84 codes and instead to code these

fibrotic lung diseases as elsewhere because of drug, radiation, or infection induced

diseases.

● Code Also / Use extra Code – In case fibrosis is a secondary illness (like systemic

sclerosis or hypersensitivity pneumonitis), the underlying disease should also be coded.

● Do Not Use Unspecified Codes – J84.10 is acceptable but more specific, such as

J84.112 (Idiopathic Pulmonary Fibrosis), is better to gather accurate data and to track

the research.

➔ ICD-10 codes are not merely administrative labels, and they shape the process of

reimbursement, eligibility to antifibrotic medications, and national disease statistics

tracking. Thus, accurate records promote enhanced care and quality of public health

records.

Epidemiology, Etiology and Pathophysiology.

There is a great range of disease categories that can be categorized as pulmonary fibrosis

since they all have the similarity of scarring the lungs no matter the initial cause.

Epidemiologically, its prevalence is changing with the subtype, diagnostic criteria and population

geography of the study. Idiopathic Pulmonary Fibrosis (IPF) is the most commonly studied

subtype and it is a disease that normally develops in older adults with a world-wide incidence of

3-9 cases per 100,000 persons per year. It is prevalent in men compared to women and mostly

occurs when one is beyond the age of 50. The disease progresses indefinitely after which the

median survival after being diagnosed is just 3-5 years despite treatment.

Pulmonary fibrosis may be a primary idiopathic condition, or idiopathic secondary, or

environmental, occupational, autoimmune, or drug-induced. To identify the appropriate ICD-10

code and management strategy, it is important to identify the cause.

Major Categories of Etiology.

● Idiopathic Pulmonary Fibrosis (IPF) – This is the most prevalent type, and it is of an

unknown etiology that presents with the typical pattern of the usual interstitial pneumonia

(UIP) on the radiograph.

● Connective Tissue Disease-Associated Pulmonary Fibrosis: This is observed in

systemic sclerosis, rheumatoid arthritis and lupus.

● Occupational and Environmental Fibrosis – This is as a result of sustained exposure

to silica dust, asbestos or metal fumes.

● Radiation-Induced Pulmonary Fibrosis– This usually happens many months or years

following radiotherapy to the chest (e.g. of breast or lung cancer).

● Drug-Induced Fibrosis – There are some drugs like bleomycin, methotrexate and

amiodarone which have fibrosis as a side effect

● Hypersensitivity Pneumonitis (Chronic Type) – Occurs when the individual is exposed

to organic antigens (like mold, bird proteins or farm dust) on several occasions.

● Genetic and Familial Forms – There are also cases in which a family inherits some

mutation that affects the telomere maintenance or surfactant proteins which puts the

family at risk of early fibrosis.

PathophysiologyScarring of the lung interstitium is permanent and the pathological hallmark of pulmonary

fibrosis. It starts with the damage of the alveolar epithelium and microvasculature, which leads

to the development of inflammation, the growth of fibroblasts, and the deposition of collagen.

The alveolar walls thicken, the lung architecture gets distorted, and its elasticity is lost over time.

➔ The important biological processes are:

● Enhanced transforming growth factor-beta (TGF-b) that stimulates the conversion of

fibroblasts to myofibroblasts.

● Continuation of the injury cycle by oxidative stress and apoptosis of the epithelial cell.

● Over growth of extracellular matrix (ECM), stiffening of lungs.

● Microvascular remodeling which causes secondary pulmonary hypertension.

➢ This scarring causes progressive loss of compliance and gas exchange in the lung

resulting in dyspnea (shortness of breath), dry cough and chronic hypoxemia. Although

inflammation fades away, the fibrotic tissue is left behind thus making the process to be

a one way process. When fibrosis becomes critical, respiratory failure is the only

inevitable outcome unless lung transplantation is done.

Clinical Presentation, Diagnosis, and treatment.

➔ Clinical Presentation

Pulmonary fibrosis is insidious, and it progresses in months or years. Progressive exertional

dyspnea is the most typical manifestation, and the chronic dry cough is the next symptom. The

consequences of fatigue, weight loss and lack of exercise tolerance are normal as the illness

progresses. Physical examination: the clinician can check out:

● Velcro crackles bilaterally at the bases of the lungs.

● Digital clubbing of fingers.

● Signs of right heart strain in the end-stages, and cyanosis.

● There are patients who undergo sudden worsening that is referred to as acute

exacerbations which are characterized by a rapid worsening of oxygenation and

development of new infiltrates in the course of imaging.

➔ Diagnosis

Etymology Diagnosis involves clinical, radiologic & in some conditions histopathologic data:

● History and Examination Determinants of possible exposures, autoimmune symptoms,

and drug use.

● High-Resolution Computed Tomography (HRCT) — The best image tool. The typical

Usual Interstitial Pneumonia (UIP) appearance has reticular opacities, subpleural

honeycombing, and traction bronchiectasis.

● Pulmonary Function Tests (PFTs) – Discloses restrictive trends having smaller total

lung capacity (TLC) and diffusing capacity of carbon monoxide (DLCO).

● Serologic Tests--Assist in the elimination of connective tissue diseases.

● Lung Biopsy – It is used when the findings of the HRCT are inconclusive. It establishes

such histopathologic characteristics as patchy fibrosis, foci of fibroblasts, and

honeycombing.

● Multidisciplinary Discussion (MDD) – A group of pulmonologists, radiologists, and

pathologists is involved in discussing data to determine final diagnosis.➔ Management Strategies

There is no cure but the treatments are aimed at reducing the progression, relieving symptoms

and ensuring quality of life.

Antifibrotic Medications

● Pirfenidone and Nintedanib are approved drugs in the USA which slow the progression

of lung function in IPF and other fibrosing interstitial lung diseases.

● Oxygen Therapy – Supplemental oxygen is utilized in the prevention of hypoxemia with

activities and rest.

● Pulmonary Rehabilitation Exercise training, nutrition and education to enhance

endurance and daily performance.

● Vaccination and Infection Prevention- Influenza and pneumococcal vaccines

decrease complications of the respiratory tract.

● Treatment of Comorbidities – manage gastroesophageal reflux, pulmonary

hypertension and sleep apnea.

● Lung Transplantation – It is the only procedure that provides long-term survival in

end-stage fibrosis.

● Palliative and Supportive Care – Concentrates on the symptom management,

counseling and advanced care planning.

Prognosis, Problems and Conclusion.

➔ Prognosis

Pulmonary fibrosis is progressive and is normally fatal after a few years of diagnosis. In the case

of IPF, the median survival is about 3-5 years, the rates of survival differ, depending on age,

baseline lung function, comorbidity, and treatment response. The poor prognostic indicators are:

● Older age and male gender.

● Extensive fibrosis on HRCT.

● Forced vital capacity (FVC) rapidly reducing.

● Numerous acute exacerbation.

● Pulmonary hypertension happens concurrently.

● Antifibrotic therapy is able to delay but not prevent the decline. The only curative

treatment is lung transplantation which is limited by the number of donors and their

eligibility.

➔ Problems with Diagnosis and Coding.

One of the key clinical issues is the identification of the various forms of fibrosing lung diseases

as the symptoms and appearance are similar to each other. Incorrect ICD-10 coding mostly

results as a consequence of misclassification. Such as when J84.10 (unspecified) should be

used instead of J84.112 (idiopathic), the accuracy of the data may be distorted, and it will affect

the possibility of receiving treatment. Also, fibrosis that is obtained as a result of radiation or

drugs needs to be connected to the causal agent using code also instructions (e.g., J70.1

radiation-induced).

● Properly documenting is required by healthcare providers stating:

● The presence or absence of fibrosis is idiopathic or secondary.

● Referred exposure or sexually transmitted disease.

● Diagnosis with the use of HRCT or multidisciplinary assessment.In their turn, coders are required to use certain ICD-10 codes based on documentation to

enhance the accuracy of epidemiological and reimbursement fairness.

Future Directions

Future studies are looking into the development of specific molecular therapies which can

prevent or reverse fibrosis by preventing pathways like TGF-b and PDGF. Genetics research is

yielding at risk variants of surfactant and telomerase genes. In the near future, artificial

intelligence and imaging biomarkers can be used to detect and manage it earlier and create

personalized approaches. The registries of the world with correct ICD coding also enhance the

knowledge of disease burden and outcomes.

Summary

Pulmonary fibrosis is a continuum of noninfectious chronic interstitial lung diseases, which is

marked by progressive scarring and dyspnea. The disease will primarily be classified as J84.1

by ICD-10 with subcodes J84.10 (unspecified) and J84.112 (idiopathic pulmonary fibrosis),

depending on the clinical diagnosis. These codes should be used correctly to ensure that data is

precise, patients are taken care of and research.

Although it has current restriction, there is an improvement in the survival and quality of life as

new antifibrotic drugs, lung transplantation, and early diagnosis are being made. The further

cooperation of clinicians, radiologists, and medical coders will guarantee proper diagnosis,

documentation, and coding that is a necessary measure on the way to the improvements in

patient outcomes and more stable worldwide health data.