Fluid & Electrolytes
Where is the majority of the body's Potassium and Sodium located?
Potassium is primarily Intracellular (inside the cell), while Sodium is primarily Extracellular/Intravascular (outside the cell/in the blood).
A nurse is reviewing labs for a patient with a Potassium of 5.8 mEq/L. The nurse looks at the heart monitor and sees peaked T-waves. Based on the clinical reasoning cycle, what is the physiological priority for this patient?
Hyperkalemia (High Potassium).
Cardiac Arrhythmias. (The nurse must process that high potassium directly impairs the heart's electrical conduction).
What are the normal ranges for pH, PaCO2, and HCO3?
pH: 7.35–7.45; PaCO2: 35–45; HCO3: 22–28.
What is the most critical item that must be signed and on the chart before a patient receives any sedative medications?
Informed Consent
A patient with a Sodium of 152 mEq/L is thirsty and agitated. The nurse notices the patient has a history of heart failure. Why would the nurse question an order for 0.9% Normal Saline for this patient?
0.9% NS contains more sodium; the nurse should decide that a hypotonic solution (0.45% NS) or D5W is better to dilute the sodium without adding more salt to a heart failure patient.
Which type of fluid causes water to move out of the cells and into the intravascular space, potentially causing cellular shrinkage?
Hypertonic Fluids (e.g., 3% NS, Albumin).
A patient reports numbness and tingling around the mouth and a positive Chvostek’s sign (facial twitch). What is the likely cause?
Hypocalcemia (Low Calcium).
Interpret these results: pH 7.28, PaCO2 50, HCO3 24
Uncompensated Respiratory Acidosis.
(Intra-Op): A patient under general anesthesia develops muscle rigidity and a rapidly rising temperature. What is the priority medication to administer?
Dantrolene Sodium
A patient with severe Hypocalcemia is receiving IV Calcium Gluconate. Which finding during the infusion would cause the nurse to Act by stopping the pump immediately?
Extravasation (redness/swelling at the IV site) or Cardiac Bradycardia (calcium can slow the heart rate if given too fast).
A patient has lost a significant amount of blood and needs volume expansion. Which two common IV fluids are considered Isotonic and will stay in the intravascular space?
0.9% Normal Saline (NS) and Lactated Ringer’s (LR).
A patient with a Sodium level of 116 mEq/L is at extreme risk for which life-threatening complication?
Cerebral Edema (leading to seizures or coma).
Interpret these results: pH 7.52, PaCO2 38, HCO3 32
Uncompensated Metabolic Alkalosis.
What is the nurse’s legal role when a patient is signing a surgical consent form?
To witness the signature and ensure the patient is competent/acting voluntarily.
A nurse is caring for a patient who is "NPO after midnight" for surgery. The patient’s morning labs show a Potassium of 3.1 mEq/L. What is the nurse's priority action before the patient goes to the OR?
Notify the surgeon/anesthesiologist. (The nurse must reflect on the fact that low potassium increases the risk of cardiac arrest under anesthesia).
Why is D5W considered "physiologically hypotonic" even though it is isotonic in the bag?
Once infused, the body quickly metabolizes the dextrose, leaving only "free water," which then moves into the cells.
What is generally considered the first sign of magnesium toxicity (hypermagnesemia)? Normal Mag level 1.7 to 2.2 mg/dL
Decreased or absent Deep Tendon Reflexes (DTRs), such as a diminished patellar reflex.Magnesium acts like a "sedative" to the nervous system when levels are high.
If the pH is normal but both the CO2 and HCO3 are abnormal, the body has achieved what?
Full Compensation.
(OR Staff): Which member of the OR team is responsible for maintaining the sterile field and passing instruments?
The Scrub Nurse (or Scrub Tech).
A Post-op patient has a blood pressure of 88/50 and a heart rate of 120. The nurse notes the surgical dressing is saturated with bright red blood. What is the nurse's interpretation of this data?
The patient is likely experiencing Hypovolemic Shock due to hemorrhage.
Using the Clinical Reasoning Cycle, a nurse notes a patient has "tented" skin turgor and a high urine specific gravity. What is the most appropriate Nursing Diagnosis?
Fluid Volume Deficit related to active fluid loss.
A patient with a magnesium level of 3.6 mg/dL is mistakenly served a dinner with spinach salad and almonds. Why is this a safety concern?
These foods are high in magnesium and will further increase the patient's already toxic levels.
A patient with Diabetic Ketoacidosis (DKA) has a pH of 7.15. Which organ system will attempt to compensate, and how?
The Lungs (Respiratory system) will compensate by increasing the rate/depth of breathing (Kussmaul respirations) to "blow off" CO2.
A post-op patient has a low-grade fever and diminished breath sounds at the bases 12 hours after surgery. What is the priority nursing intervention?
Encourage the use of the Incentive Spirometer to prevent Atelectasis.
A patient is in the OR holding area and tells the nurse, "I'm still not really sure why they are removing my gallbladder." What must the nurse do immediately?