⚕️ ICD-10 CM G90.4 - Autonomic Dysreflexia

Code Description

ICD-10 CM G90.4 represents Autonomic Dysreflexia. This is a potentially life-threatening medical emergency that occurs in individuals with spinal cord injuries (SCI), typically at the T6 level or above. It is characterized by an overreaction of the autonomic nervous system to a stimulus below the level of injury, resulting in uncontrolled hypertension.^{CMS ICD-10-CM}

Clinical Overview

Autonomic dysreflexia is a syndrome of massive involuntary reflex activation of the sympathetic nervous system. Common triggers include bladder distension, bowel impaction, or skin irritation. Symptoms include severe headache, sweating above the level of injury, flushing, and bradycardia.^NINDS

Coding Hierarchy (Code Tree)

This code exists within the following hierarchy in the ICD-10-CM structure:

Chapter VI: Diseases of the nervous system (G00-G99)
- Block: Disorders of autonomic nervous system (G90)
  - Category: Disorders of autonomic nervous system (G90)
    - Subcategory: Autonomic dysreflexia (G90.4)

Official Coding Guidelines & Notes

Includes

This code includes conditions specified as autonomic hyperreflexia.^{WHO ICD-10}

Excludes1

Note: Excludes1 means “not coded here”. If the patient has this condition, do not use G90.4.

None specifically listed for G90.4 at the subcategory level, but refer to parent code G90 for broader exclusions.^{CMS ICD-10}

Excludes2

Note: Excludes2 means “not included here”. The patient may have both conditions, but code separately.

Complications of internal prosthetic devices, implants and grafts (T85.-)
Intraoperative autonomic dysreflexia (G90.A)^{CMS ICD-10}

Coding Tips

Sequence First: If the autonomic dysreflexia is due to a specific underlying condition (e.g., blocked catheter), code the underlying cause first if applicable, followed by G90.4.
Spinal Cord Injury: Always code the underlying spinal cord injury status (e.g., Z99.3 Dependence on wheelchair or specific SCI code from chapter 19) if applicable.^{Coding Clinic}
Intraoperative: If the dysreflexia occurs during a procedure, use G90.A instead of G90.4.

Reimbursement & Risk Adjustment

HCC (Hierarchical Condition Category)

Status: Yes
Model: CMS-HCC V28 (2024 Model)
Category: This code often maps to neurological HCC categories which impact Risk Adjustment Factor (RAF) scores for Medicare Advantage plans.^{CMS Risk Adjustment}
Impact: Documenting G90.4 accurately ensures proper capture of patient complexity and risk adjustment payment eligibility.

wRVU (Work Relative Value Unit)

Value: N/A
Reason: G90.4 is an ICD-10-CM diagnosis code. wRVU values are assigned to CPT/HCPCS procedure codes, not diagnosis codes.^{AMA CPT}

Assistant Surgeon Payable

Status: N/A
Reason: Assistant surgeon modifiers (e.g., -80, -81, -82) apply to surgical CPT codes. Diagnosis codes do not have assistant payable status.^{CMS MPFS}

Applicability: Yes
Impact: While G90.4 does not have a DRG itself, it influences DRG assignment when used as a principal or secondary diagnosis.
MDC: Likely falls under MDC 01 (Diseases and Disorders of the Nervous System).
CC/MCC: May qualify as a Complication or Comorbidity (CC) or Major Complication or Comorbidity (MCC) depending on the specific DRG logic and presence of other conditions, potentially increasing reimbursement weight.^{CMS MS-DRG}

Coding Examples

Example 1: Routine Management

Scenario: A patient with a history of T4 spinal cord injury presents to the ER with severe headache and hypertension due to a blocked Foley catheter. The catheter is replaced, and the patient is diagnosed with autonomic dysreflexia.

Primary Diagnosis: G90.4 (Autonomic dysreflexia)
Secondary Diagnosis: T83.011A (Breakdown (mechanical) of urinary catheter, initial encounter)
Secondary Diagnosis: G82.20 (paraplegia, unspecified)
Note: Ensure the trigger (catheter issue) is coded.^{Coding Clinic}

Example 2: Intraoperative Event

Scenario: During a urological procedure on a patient with SCI, the patient experiences a spike in blood pressure indicative of autonomic dysreflexia.

Diagnosis: G90.A (Intraoperative autonomic dysreflexia)
Note: Do not use G90.4 for intraoperative events.^{CMS ICD-10}

Example 3: Chronic Condition Management

Scenario: Patient seen in neurology clinic for management of chronic autonomic dysreflexia symptoms unrelated to an acute trigger.

Diagnosis: G90.4
Secondary Diagnosis: Z99.3 (Dependence on wheelchair)
Secondary Diagnosis: G82.50 (Quadriplegia, unspecified)
Note: Capture HCC status for risk adjustment.^{CMS Risk Adjustment}

While G90.4 does not use modifiers, associated E/M or Procedure codes might:

-25: Significant, Separately Identifiable Evaluation and Management Service by the Same Physician or Other Qualified Health Care Professional on the Same Day of the Procedure or Other Service.
-59: Distinct Procedural Service.
-E1 - -E4: Eyelid modifiers (if applicable to related procedures).
-RT / -LT: Right Side / Left Side.

Sources

^{CMS ICD-10} Centers for Medicare & Medicaid Services, ICD-10-CM Official Guidelines. ^NINDS National Institute of Neurological Disorders and Stroke, Autonomic Dysreflexia Information Page. ^{WHO ICD-10} World Health Organization, ICD-10 Version:2019. ^{Coding Clinic} AHA Coding Clinic for ICD-10-CM/PCS. ^{CMS Risk Adjustment} CMS Medicare Advantage Risk Adjustment Data Processing System. ^{AMA CPT} American Medical Association, CPT Professional Edition. ^{CMS MPFS} CMS Medicare Physician Fee Schedule. ^{CMS MS-DRG} CMS Medicare Severity Diagnosis Related Groups Definitions Manual.

Explorer

G90.4