The MURDER mnemonic is a handy tool used to remember the 6 things to look in Hyperkalemia.

Because hyperkalemia is a higher than normal concentration outside of the cells the concentration gradient and resultant electrical gradient acrosss the membrane are affected. The result is that the excitable cells, those of the myocardium, nerve cells and smooth muscle cells all become less excitable.

What do the letters of the MURDER Mnemonic mean?

M – Muscle Weakness

Muscle weakness can result from both the deleterious effect of high serum potassium on muscle cells and compromised neuromuscular function.

U – Urine  (Oliguria / Anuria)

Disorders of urine output are a cause rather than the result of hyperkalemia, but they are nonetheless an associated sign. A Patient with oliguria or anuria is unable to excrete potassium. These patients often have chronic kidney disease or an acute kidney injury.

R – Respiratory Distress

Respiratory Distress results from weakening of the muscles involved in breathing

D – Decreased Cardiac Contractility

Decreased cardiac contractility leads to lower cardiac output and potentially low blood pressure.

E – ECG changes

It also leads to conduction abnormalities and blocks. Peaked T waves, flattened P waves, and sinusoidal waves are among the well-known ECG changes.

R – Reflexivity (decreased)

Decreased reflexivity is the result of the dysfunction of the nerve cells.

The MURDER Mnemonic: A Tool for Recognizing Hyperkalemia

Medications –

• Gather information about the patient’s current medications, including prescription drugs, over-the-counter medications, and herbal supplements.
• Be thorough and ask about dosages, frequency and any recent changes in medications.

Past (Pertinent Medical History)  –

• Ask about the patient’s medical past as it pertains to the current condition. Ask about chronic conditions, surgeries, hospitalizations, and significant illnesses.
• Try to keep the focus on relevant medical events that may impact the current situation.

Last (Oral Intake)  –

• Determine when the patient last ate or drank. This information is vital for assessing potential complications during procedures or surgeries.
• This line of questioning may also be relevant for assessing diabetic patients.

Events (Prior to Current Situation)  –

• To understand the context, ask what events or circumstances led to the patient seeking medical attention?
• When assessing trauma cases, explore the mechanism of injury (e.g., fall, motor vehicle accident).

A SAMPLE history is an essential and valuable tool, especially in emergency situations. It should be used in conjunction with other structured history such as OPQRST, vitals and a thorough physical assessment to create a complete picture of the patient’s illness.