May 26, 2008
Coding for Electrolyte Disorders
Electrolyte disorders are classified to ICD-9-CM category 276, Disorders of fluid, electrolyte, and acid-base balance. This column focuses on abnormal potassium and sodium levels in the blood.
Common causes of hypernatremia include inadequate water intake, inappropriate water excretion, and the intake of a hypertonic fluid. Symptoms include lethargy, weakness, irritability, and edema, and seizures and coma may occur in more severe cases. The treatment for hypernatremia is the infusion of a water solution containing 0.9% sodium chloride.
Common causes of hyponatremia include the consumption of excessive water during exercise, diuretics, syndrome of inappropriate antidiuretic hormone (SIADH; 253.6), dehydration, diet, and congestive heart failure. Per coding directives, if dehydration is documented with hyponatremia, assign only a code for the hyponatremia (276.1). In addition, if the patient has SIADH and hyponatremia, only code 253.6 is assigned. Hyponatremia is an integral part of the SIADH and would not be coded separately (AHA Coding Clinic for ICD-9-CM, 1993, fifth issue, page 8).
Although a patient with mild hypokalemia does not have any symptoms, moderate hypokalemia results in confusion, disorientation, weakness, and discomfort/cramps of muscles. Hypokalemia is treated with potassium supplements, potassium chloride, potassium bicarbonate, and potassium acetate.
It is the physician’s responsibility to document the patient’s diagnosis. In the inpatient setting, a diagnosis based on an abnormal lab result or diagnostic test should not be determined by someone other than a physician. The physician must document the diagnosis in the medical record before it can be coded. In addition, it is not adequate for a physician only to use arrows (Ý or ß) to indicate a diagnosis, even if treatment was given for that condition. For example, the physician documents “Na ß 129. Decrease fluid intake. Change IV fluids.” In this example, hyponatremia (276.1) could not be coded without the physician documenting it. Query the physician regarding the patient’s specific diagnosis.
Coding and sequencing for electrolyte disorders are dependent on the physician documentation in the medical record and application of the Official Coding Guidelines for inpatient care. Also, use specific AHA Coding Clinic for ICD-9-CM and American Medical Association CPT Assistant references to ensure complete and accurate coding.
— This information was prepared by Audrey Howard, RHIA, of 3M Consulting Services. 3M Consulting Services is a business of 3M Health Information Systems, a supplier of coding and classification systems to nearly 5,000 healthcare providers. The company and its representatives do not assume any responsibility for reimbursement decisions or claims denials made by providers or payers as the result of the misuse of this coding information. More information about 3M Health Information Systems is available at www.3mhis.com or by calling 800-367-2447.