ED Coding and Reimbursement Alert

How should a tetanus shot factor into calculating MDM risk?

When coding an evaluation and management (E/M) service, coders must calculate the level of medical decision making (MDM) associated with the patient’s care.

According to Todd Thomas, CPC, CCS-P, president of ERcoder, Inc., in Edmond, Oklahoma: “While we are currently in a transition period as ED coders are preparing for the implementation of the 2023 E/M guidelines, current and future MDM requirements include ‘risk of complications and/or morbidity or mortality’ as part of assigning a value to the MDM.”

Where a tetanus shot fits into the Table of Risk (1995 Documentation Guidelines) or Risk column (2023 Documentation Guidelines) has been a topic of debate among ED coders. Here’s a closer look at the debate.

Know Tetanus Shot Side Effects

Most patients who receive a tetanus shot are unlikely to experience an adverse reaction. As with most medicines, however, there is always the possibility of side effects. Most frequently reported are mild side effects of a tetanus shot that include:

• redness and swelling at the injection site,
• body aches,
• headache, and
• tiredness or feeling weak.

Some patients have experienced more significant adverse reactions after a tetanus vaccination, with symptoms such as:

• Fever;
• Nausea, vomiting, or diarrhea; and
• Rash or swollen glands.

In some cases, a tetanus shot may cause some patients to suffer serious side effects that need medical attention. These side effects include

• Severe pain and/or swelling
• Severe allergic reaction that could include:
  o difficulty breathing or swallowing;
  o hives;
  o itchy throat, feet, or hands;
  o rapid heartbeat;
  o sudden severe fatigue; and
  o swelling in the face, eyes, or airways

These reactions could happen immediately or hours after administering the injection.

Know Vaccine Types

Thomas says that ED coders may see several types of tetanus shots documented in an emergency chart. Vaccines may be referred to as:

• Tdap: Includes tetanus, diphtheria, and pertussis (whooping cough)
• DTaP: Often used for young children; includes tetanus, diphtheria, and pertussis.
• Td or DT: Includes tetanus and diphtheria; often used as a tetanus booster.

Some patients may have contraindications for a tetanus shot. The ED physician will need to screen patients for complications they may have experienced after a previous tetanus vaccination. Patients who have had allergic reactions, severe pain, swelling, or seizures may not be candidates for a tetanus shot.

Patients may have chronic conditions that should be considered before administering a tetanus vaccine. Patients with a history of nervous system conditions, Guillain-Barre syndrome, or other diseases where the immune system attacks nerve cells may have a higher risk of side effects from a tetanus vaccine.

While side effects of a tetanus shot are uncommon, usually mild when they occur, and in most cases are likely to resolve without additional treatment, the ED physician’s decision to administer a tetanus vaccination does come with some risk. Therefore, it should be factored into the MDM calculation.

So where should it fit into the Table of Risk/Risk Column? “The choice seems to be between low risk (over-the-counter drugs on the Table of Risk) or moderate risk (prescription drug management on the Table of Risk and Risk Column),” says Thomas.

A patient can’t walk into a pharmacy and get a tetanus shot off the shelf. Tetanus vaccines are not available without a prescription and require formal Food and Drug Administration (FDA) approval. In short, the tetanus vaccine requires a doctor’s order/prescription. It is a parenteral medication (given by injection). Both factors suggest that a tetanus shot exceeds treatment decisions that are usually considered low risk.

Before administration of a tetanus shot, the ED physician must consider the type of wound, whether the patient’s tetanus is up to date, the patient’s past experience with the immunization, and any underlying medical conditions. All of these seem to indicate that the tetanus vaccination administration is more consistent with a moderate risk treatment decision.