ICU Metabolic Panels and Electrolytes Vocabulary

Vocabulary terms, lab values, and clinical manifestations related to basic and comprehensive metabolic panels and critical electrolytes.

Basic Metabolic Panel (BMP)

A group of lab tests primarily looking at a patient's electrolytes and kidney function, commonly grouped as the Chem 8.

Comprehensive Metabolic Panel (CMP)

A lab panel inclusive of all tests in the Basic Metabolic Panel (BMP) along with additional tests assessing liver function.

Green Top Collection Tube

The standard blood collection tube used to send off metabolic panels, chemistries, lipid panels, cardiac markers, and ammonia levels.

Lab Result Skeleton

A standard form diagram used to write Chem 8 results where column 1 contains cations, column 2 contains anions, column 3 contains kidney function, and glucose is off to the right.

Sodium (Serum Normal)

The major extracellular cation involved in maintaining serum osmolality and fluid shifts, with a normal reference range of $135 - 145\,mEq/L$.

Hypernatremia

Serum sodium level greater than $145 - 150\,mEq/L$, presenting primarily with neurologic symptoms and treated by reducing sodium by $0.5 - 1\,mEq/L\text{ per hour}$.

Hyponatremia

Serum sodium level generally less than $130\,mEq/L$, treated with a gradual increase of $0.5\,mEq/L\text{ per hour}$, or $2 - 4\,mEq/L\text{ per hour}$ if seizures are present.

Potassium (Serum Normal)

The primary intracellular cation involved in muscle contraction, fluid balance, and nerve transmission, with a normal range of $3.5 - 5\,mEq/L$.

Hyperkalemia

Elevated serum potassium ($6 - 7\,mEq/L$ moderate, $> 7\,mEq/L$ severe) that manifests with peak T waves on ECG and can cause idioventricular rhythm or asystolic cardiac arrest.

Hypokalemia

Decreased serum potassium ($< 3.5\,mEq/L$) causing muscle weakness and ECG changes such as U waves or flattened T waves.

Calcium (Serum Normal)

The most abundant mineral in the body involved in cellular processes, with a normal reference range of $8.5 - 10.5\,mEq/L$.

Hypercalcemia

Serum calcium level greater than $10.5\,mEq/L$, commonly caused by hyperparathyroidism; levels above $15\,mEq/L$ can lead to AV blocks and cardiac arrest.

Hypocalcemia

Serum calcium level less than $8.5\,mEq/L$, presenting with symptoms like paresthesia, muscle cramps, hyperreflexia, tetany, stridor, and seizures.

Chloride (Serum Normal)

A key anion maintaining acid-base balance inversely related to bicarbonate, with a normal reference range of $95 - 105\,mEq/L$.

Hyperchloremia

Elevated chloride levels typically caused by iatrogenic normal saline overload or bicarbonate loss, leading to hyperchloremic metabolic acidosis.

Hypochloremia

Low serum chloride caused by GI loss, renal loss, or hypotonic fluid dilution, which can lead to hypochloremic metabolic alkalosis.

Bicarbonate / CO2 (Serum Normal)

An anion with a normal value of $23 - 29\,mEq/L$ where $95\%$ of measured $CO_2$ represents bicarbonate functioning as an acid-base buffer.

Blood Urea Nitrogen (BUN)

A standard kidney function test on the BMP with a normal reference range of $6 - 20\,mg/dL$.

Creatinine

A laboratory marker of kidney function evaluated on the BMP with a normal reference range of $0.8 - 1.3\,mg/dL$.

Glucose (Normal Range)

A key blood sugar measurement reported on the metabolic panel with a normal value of $65 - 110\,mg/dL$.

Alkaline Phosphatase (Alk Phos)

A liver function test included on the Comprehensive Metabolic Panel with a normal range of $20 - 30\,U/L$.

AST and ALT

Aspartate transaminase and alanine transaminase, two liver enzymes measured on a CMP, both having a normal range of $5 - 30\,U/L$.

Bilirubin

A liver function parameter measured as part of a CMP with a normal range of $0.2 - 1.9\,mg/dL$.

Total Protein

A liver function measurement included on the CMP with a normal reference range of $6.3 - 7.9\,g/L$.

Albumin

A liver function protein on the CMP with a normal range of $3.4 - 5.4\,g/L$ that binds $50\%$ of circulating calcium.

Ionized Calcium

The unbound form of calcium readily available for body use, with a normal range of $4.5 - 5.6\,mg/dL$ or $1.1 - 1.3\,mmol/L$, having an inverse relationship with albumin.

Phosphorus

An electrolyte playing a role in bone health and muscle contraction that maintains an inverse relationship with calcium, with a normal range of $3 - 4.5\,mg/dL$.

Magnesium (Serum Normal)

An essential electrolyte helping transfer sodium and potassium across cell membranes, with a normal range of $1.5 - 2\,mEq/L$.

Hypermagnesemia

Serum magnesium greater than $2.2\,mEq/L$, commonly caused by renal failure, leading to vasodilation, severe hypotension, bradycardia, and cardiac arrest.

Hypomagnesemia

Serum magnesium less than $1.2\,mEq/L$, presenting with muscle fasciculations, tetany, seizures, and arrhythmias such as torsades de pointes.