Laboratory Tutorial
 

Module Description 

This module is designed as a tutorial to assist nursing students with preparation for the National Council Licensure Examination for Registered Nurses (NCLEX-RN) Computer Adaptive Testing (CAT). Students will review pertinent information related to laboratory values. 

After completing this module, the learner will be able to: 

1. Identify the laboratory values that require frequent monitoring for clients. 
2. List the laboratory values that must be monitored. 

Online Tutorial 

According to Fischback (A Manual of Laboratory and Diagnostic Tests), it is important to correlate a thorough history and physical with laboratory values to confirm a diagnosis and implement appropriate nuring interventions. Laboratory analysis includes basic screening, selective monitoring, specific evaluations, and regularly scheduled follow-up screening. 

Sodium (Na+)
Normal level = 135 to 145 mEq/L (adult)

• Required in acid-base and osmotic pressure balance, nerve function and water equilibrium. 

<Increased 
Lethargy, irritability, muscle twitching, tremors, dry skin and mucous membranes, fever, hypotension, disorientation, delirium, cerebral hemorrhage, coma 

Potassium (K+)
Normal level = 3.5 to 5 mEq/L (adult)

• Major factor in carbohydrate metabolism, osmotic pressure balance, acid-base balance and normal muscle contraction. 

<Increased 
Muscle weakness, paralysis, numbness and tingling, ventricular fibrillation, cardiac arrest, tall tented T waves

Calcium (Ca++)
Normal level = 8.5 to 10 mg/dL

• Involved in bone and tooth formation, blood coagulation, nerve function, muscle contraction. 

<Increased 
Muscle weakness, bone fragility, kidney stones, loss of appetite, thirst, frequent urination, lethargy, fatigue, joint pains, memory loss, depression, constipation, anorexia, nausea and vomiting, abdominal pain, ileus, polyuria, nocturia, and polydipsia, emotional lability, confusion, delirium, psychosis, stupor, coma, cardiac arrhythmias with shortened QT segment

Magnesium (Mg2+)
Normal level = 1.3 to 2.1 mEq/L

• Required for activation of an enzyme necessary for energy metabolism and bone formation. 

<Increased
Muscle weakness, drowsiness, lethargy, hypotension, paralysis, coma, cardiac and respiratory problems

Normal Adult Level Blood Sugars

• Fasting Blood Sugar (FBS) 70-100 mg/dL
• 2 hr Postprandial (PP) 90-140 mg/dL
• Random Blood Sugar 70-160 mg/dL 

Hypoglycemia
Restlessness· Irritability· Confusion· Trembling· Slurred speech · Headache · Tingling lips · Paresthesia· Diaphoresis (cool skin) · Pallor· Tachycardia· Shallow respirations· Hypertension· Weakness · Hunger · Coma · Tremors 

Hyperglycemia
Diabetic Ketoacidosis · Fatigue · Flushed, dry skin· Dry mouth · Increased thirst · Increased urination· Blurry vision · Headache· Nausea and Vomiting· Dehydration· Weak, rapid pulse· Hypotension· High blood glucose levels (>240 mg/dL).· Ketones in urine· Increased thirst and urination · Nausea, vomiting, and/or stomach pain· Changes in or difficulty breathing (Kussmaul’s respirations)· Acid or fruity smell on breath (Acetone breath)· Flushing · Dehydration · Fatigue · Stupor and coma

Respiratory Acidosis

• Excessive accumulation of carbon dioxide resulting in excessive acidity of body fluids.
• < ph
• >HCO3
• >pCo2 

Signs and Symptoms: Shortness of breath, fatigue, chronic cough, or wheezing, confusion, irritiability, or lethargy.

Treatment: Brochodilators, oxygen, and mechanical ventilation.

Respiratory Alkalosis

• Excessive loss of carbon dioxide resulting in excessive alkalinity of body fluids.
• >ph 
• <HCO3
• <pCO2 

Signs and Symptoms: Confusion, muscle twitching, hand tremors, nausea, vomiting, light-headedness, and paresthesia of the extremities.

Treatment: Breathe into a paper bag to case retention of carbon dioxide and readjust ventilator settings.

Metabolic Acidosis

• Excessive acidity of body fluids.
• <ph
• <HCO3
• <pCO2 

Signs and Symptoms: Shortness of breath, lethargy, and confusion.

Treatment: Replace sodium bicarbonate.

Metabolic Alkalosis

• Excessive accumulation of  alkaline (bicarbonate) in the blood.
• >ph 
• >HCO3
• >pCO2 

Signs and Symptoms: Cyanosis, nausea, vomiting, irritability, twitching, confusion, tachycardia, hypotension, convulsions, and coma.

Treatment: Replace fluids, potassium, EKG monitoring, drugs to regulate heart rate and blood pressure, drugs to control nausea and vomiting.

• mmHg = millimeters of mercury
• mEq/liter = milliequivalents per liter

An online MERLOT activity that provides practice with differentiating between different types of arterial blood gas problems.