Electrolytes in the Human Body

Electrolytes

• Electrolytes are essential minerals or ions that carry an electrical charge and play critical roles in various physiological processes throughout the body.
• The main electrolytes in the human body include:
  • Sodium (Na+)
  • Potassium (K+)
  • Chloride (Cl-)
  • Calcium (Ca2+)
  • Magnesium (Mg2+)
  • Phosphate (PO43-)
  • Bicarbonate (HCO3-)
• There are 4 common electrolytes that medical practitioners order:
  • Sodium (Na) - responsible for normal distribution of water and transmission of nerve impulses
  • Potassium (K) - functions in muscle contractions and conduction of nervous impulses
  • Chloride (Cl) - functions to maintain water balance along with sodium
  • Bicarbonate (HCO3-) - maintains the acid-base balance of the body

Renal Function

• Renal function refers to the physiological processes carried out by the kidneys, which play a crucial role in maintaining overall health and homeostasis within the body.
• Tests used for renal function:
  • Urea
  • Creatinine
  • Uric Acid
  • Creatine Clearance (requires both 24-hour urine specimen and blood sample)

Lipids

• Lipids are a diverse group of organic molecules that serve essential roles in cellular structure, energy storage, insulation, and signaling within the body.
• Lipids play an important role in many metabolic processes, including:
  • Hormone or hormone precursors
  • Energy storage and metabolic fuel
  • Structural and functional component in cell membrane
  • Insulation to allow conduction of nerve impulses or heat loss
• There is a correlation between lipids and atherosclerosis (which can lead to coronary heart disease)
• Tests used for lipids:
  • Cholesterol
  • Triglycerides
  • Low density lipoprotein (LDL)
  • High density lipoprotein (HDL)

Cardiac Disease - Myocardial Injury

• Cardiac disease, particularly myocardial injury, refers to damage or impairment to the heart muscle (myocardium) due to various pathological processes.
• Myocardial injury can occur as a result of acute events such as myocardial infarction (heart attack).
• Today, there are 3 basic chemistry tests used to diagnose a myocardial infarction or injury:
  • Myoglobin (MB)
  • Troponins
  • Creatine Kinase Myoglobin (CK-MB)

Liver Tests

• Liver tests are a group of blood tests used to assess the health and function of the liver.
• These tests provide valuable information about liver enzymes, proteins, and other markers that can indicate liver damage, inflammation, or dysfunction.
• Tests used for liver function:
  • Ammonia
  • Bilirubin
  • Alkaline phosphatase (Alk phos)
  • Gamma Glutamyl Transferase (GGT)
  • Alanine Transaminase (ALT)
  • Aspartate Transaminase (AST)
  • Lactic Dehydrogenase (LD)

Pancreatic Testing

• Pancreatic testing involves a range of laboratory tests and imaging studies used to evaluate the structure and function of the pancreas.
• Tests used for pancreatic function:
  • Lipase (LPS)
  • Amylase
  • Isoamylase

Hormones Tests

• Hormones are chemical substances produced by a gland in one part of the body and carried to a distant target organ where a regulatory response is elicited.
• Hormone tests are laboratory evaluations used to assess the levels of various hormones circulating in the bloodstream.
• Examples of hormone tests:
  • Thyroid-Stimulating Hormone (TSH)
  • Thyroxine (T4)
  • Triiodothyronine (T3)
  • Cortisol
  • Adrenocorticotropic Hormone (ACTH)
  • Follicle-Stimulating Hormone (FSH)
  • Luteinizing Hormone (LH)
  • Estradiol
  • Testosterone
  • Progesterone

Proteins

• Proteins are large, complex molecules made up of long chains of amino acids.
• The most prevalent type of protein is albumin (2/3 of the total protein).
• The other types are in a class called globulins, which include:
  • Alpha 1 globulins
  • Alpha 2 globulins
  • Beta globulins
  • Gamma globulins (most are antibodies)
• Gamma globulins are further divided into 5 groups:
  • IgA - respiratory, gut, skin, renal infections
  • IgD - chronic bacterial infections
  • IgG - autoimmune responses
  • IgE - asthma, allergic conditions
  • IgM - viral infections, blood stream infections
• Decreased immunoglobulins are seen in immunodeficiency diseases
• Protein tests:
  • Albumin
  • Total Protein
  • Protein Electrophoresis (separates serum into 5 fractions)

Other Tests

• Other tests used to assess various physiological processes:
  • Iron (FE) - test for anemia
  • TIBC - for anemia
  • Uric acid - a protein waste, increased in gout, kidney disease, liver disease, and hypertension
  • Calcium
  • Phosphate
  • Lactic Acid
  • All types of drugs

Therapeutic Drug Monitoring (TDM)

• Therapeutic drug monitoring is used to manage patients being treated with certain drugs in order to:
  • Establish a drug dosage
  • Adjust the dosage
  • Identify non-compliant patients
  • Maintain the dosage at a therapeutic level
  • Avoid toxicity
• There are 2 parts to TDM:
  • Trough and Peak
• Trough level is taken before the drug is given
• Peak levels are usually taken:
  1. 30 minutes after IV administration
  2. 60 minutes after intramuscular injection
  3. 2 hours after oral intake
• Examples of drugs monitored:
  • Digoxin
  • Theophylline
  • Vancomycin
  • Phenytoin