Blood Glucose Checks

Normal Blood Glucose Range

Fasting: 70–99 mg/dL (3.9–5.5 mmol/L)
Postprandial (2 hours after eating): <140 mg/dL (7.8 mmol/L)
Random (any time of day): <200 mg/dL (11.1 mmol/L)

Hypoglycemia (Low Blood Sugar)

• <70 mg/dL (3.9 mmol/L) → Action required

• <54 mg/dL (3.0 mmol/L) → Severe hypoglycemia (emergency)

Hyperglycemia (High Blood Sugar)

• >250 mg/dL (13.9 mmol/L) → Action required

• >300 mg/dL (16.7 mmol/L) → Severe hyperglycemia (possible DKA/HHS)

Hypoglycemia: Mild to Moderate

• Shakiness

• Sweating

• Hunger

• Irritability

• Confusion

• Weakness

Hypoglycemia: Severe

• Unconsciousness

• Seizures

• Difficulty speaking

• Extreme confusion

Hypoglycemia: What to Do:

• Administer fast-acting carbohydrates (e.g., 15–20g glucose tablets, ½ cup fruit juice, or 4–5 hard candies).

• Wait 15 minutes and recheck blood glucose.

• If still <70 mg/dL, repeat step 2.

• Once >70 mg/dL, eat a snack or meal (e.g., peanut butter + crackers, cheese + fruit).

• Notify healthcare provider if hypoglycemia is frequent or severe.

Hyperglycemia: Mild to Moderate

• Increased thirst

• Frequent urination

• Fatigue

• Blurred vision

• Headache

Hyperglycemia: Severe (DKA/HHS)

• Nausea/vomiting

• Abdominal pain

• Fruity-scented breath (DKA)

• Confusion or unconsciousness

• Rapid breathing

Hyperglycemia: What to Do:

1. Check blood glucose.

2. Drink water to stay hydrated.

3. Avoid sugary foods/beverages.

4. Take insulin or medication as prescribed (if applicable).

5. Exercise lightly (e.g., walking) if ketones are negative.

6. Monitor for ketones (if blood glucose is >250 mg/dL).

7. Seek medical help if:

   • Blood glucose remains >250 mg/dL after 2–3 corrections.

   • Ketones are present (moderate/high).

   • Symptoms of DKA/HHS appear.

What is the first step before inserting the test strip into the monitor?

Verify and confirm that the code number on the test strip matches the code number displayed on the glucose meter.

What should you do after confirming the code strip matches?

Insert the test strip into the glucose meter, ensuring it is inserted all the way and in the correct direction.

How should you prepare the patient’s finger before pricking?

Disinfect the side of the fingertip (or alternate site) with an alcohol swab and allow it to dry completely.

Where should you prick the finger, and with what?

Prick the side of the fingertip (not the center) using a lancet device.

After pricking the finger, what should you do to help the blood drop form?

Turn the finger downward to allow the blood to drop naturally with gravity.

How do you collect the blood sample on the test strip?

Gently touch the edge of the test strip to the blood drop and let the meter draw in the blood automatically.

What should you do after collecting the blood sample?

Hold gauze or cotton on the client’s finger to apply gentle pressure and stop the bleeding.

How do you get the final blood glucose reading?

Wait for the meter to display the blood glucose result and then record the reading.

What are the two main types of diabetes mellitus?

• Type 1 Diabetes (T1D): Autoimmune destruction of pancreatic beta cells → absolute insulin deficiency.

• Type 2 Diabetes (T2D): Insulin resistance + relative insulin deficiency (often linked to obesity, lifestyle, and genetics).

What are the 3 classic symptoms of diabetes (the “3 P’s”)?

1. Polyuria (excessive urination)

2. Polydipsia (excessive thirst)

3. Polyphagia (excessive hunger)

What is prediabetes?

Blood glucose levels higher than normal but not high enough for a diabetes diagnosis (fasting: 100–125 mg/dL; HbA1c: 5.7–6.4%).

Fasting plasma glucose

≥ 126 mg/dL (fasting for 8+ hours).

HbA1c

≥ 6.5% (reflects average blood glucose over 2–3 months).

Oral Glucose Tolerance Test

≥ 200 mg/dL 2 hours after drinking 75g glucose.

Random plasma glucose

≥ 200 mg/dL + symptoms (e.g., polyuria, polydipsia).

Why is HbA1c important?

• Shows long-term blood glucose control (not affected by daily fluctuations).

• Goal for diabetics: <7% (individualized based on patient).

What is the goal fasting blood glucose for a diabetic patient?

80–130 mg/dL (per ADA guidelines).

What is the goal postprandial (2-hour post-meal) blood glucose?

<180 mg/dL.

Rapid-acting

Lispro, Aspart

• Onset: 15 min

• Peak: 1-2 hr

• Duration: 3-5 hr

Short Acting

Regular — Humulin R, Novolin R

• Onset: 30 min

• Peak: 2-4 hr

• Duration: 5-8 hr

Intermediate

NPH — Humulin N, Novolin N

• Onset: 1-2 hr

• Peak: 4-12 hr

• Duration: 12-18

Long-acting

Glargine, Determir

• Onset: Slow

• Peak: No peak

• 24 hr

Which insulin cannot be mixed with others in the same syringe?

Long-acting insulin (e.g., Glargine, Detemir).

What is the Somogyi effect?

• Rebound hyperglycemia after nocturnal hypoglycemia (often due to too much evening insulin).

• Symptoms: High morning blood glucose + night sweats, headaches, or nightmares.

• Treatment: Reduce evening insulin dose or give a bedtime snack.

What is the Dawn phenomenon?

• Early morning hyperglycemia due to natural cortisol and growth hormone release (not preceded by hypoglycemia).

• Treatment: Adjust evening insulin or give more insulin overnight.

Which oral antidiabetic drug is first-line for T2D?

Metformin (unless contraindicated, e.g., kidney disease).

What is the black-box warning for SGLT2 inhibitors?

Increased risk of leg/foot amputations (e.g., Canagliflozin).

What are the signs and symptoms of Diabetic Ketoacidosis (DKA)?

• Blood glucose: >250 mg/dL

• Ketones: Present in urine/blood

• pH: <7.3 (acidosis)

• Symptoms: Nausea, vomiting, abdominal pain, fruity breath, Kussmaul respirations (deep, rapid breathing), confusion, altered mental status.

What are the signs and symptoms of Hyperosmolar Hyperglycemic State

• Blood glucose: >600 mg/dL

• No ketones (or minimal)

• Severe dehydration (dry mucous membranes, tachycardia, hypotension)

• Altered mental status (confusion, seizures, coma)

• No acidosis (pH normal)

What is the treatment for DKA and HHS?

1. IV fluids (aggressive hydration with 0.9% NS).

2. IV insulin (regular insulin).

3. Monitor electrolytes (especially potassium).

4. Treat underlying cause (e.g., infection, stroke).

What is hypoglycemia unawareness?

• The patient does not experience symptoms of hypoglycemia (e.g., shakiness, sweating).

• Risk: Increased chance of severe hypoglycemia.

• Cause: Repeated episodes of hypoglycemia → body adapts and stops releasing counterregulatory hormones.

What are the microvascular complications of diabetes?

1. Retinopathy (leading cause of blindness).

2. Nephropathy (kidney damage → end-stage renal disease).

3. Neuropathy (nerve damage → peripheral neuropathy, autonomic neuropathy).

What are the macrovascular complications of diabetes?

1. Coronary artery disease (CAD) → MI risk.

2. Cerebrovascular disease → stroke risk.

3. Peripheral artery disease (PAD) → foot ulcers, amputations.

What is diabetic foot care?

• Inspect feet daily for cuts, blisters, or sores.

• Wash feet with lukewarm water (not hot) and dry gently.

• Moisturize (but not between toes).

• Wear proper shoes (avoid barefoot walking).

• Cut nails straight across (avoid cutting corners).

• Avoid heating pads (risk of burns).

What should you teach a diabetic patient about sick day management?

• Continue taking insulin/medications (even if not eating).

• Check blood glucose every 2–4 hours.

• Drink fluids (water, broth, sugar-free drinks).

• Test for ketones if blood glucose >250 mg/dL.

• Call provider if:

  • Blood glucose >250 mg/dL for >6 hours.

  • Ketones present.

  • Unable to keep fluids down.

What should diabetics avoid in their diet?

• Sugary drinks (soda, juice).

• Refined carbs (white bread, pastries).

• Trans fats (fried foods, margarine).

• Excessive alcohol (can cause hypoglycemia).

What are the target blood glucose goals for gestational diabetes?

• Fasting: ≤95 mg/dL

• 1-hour postprandial: ≤140 mg/dL

• 2-hour postprandial: ≤120 mg/dL

What are the risks of uncontrolled gestational diabetes?

• Macrosomia (large baby).

• Pre-eclampsia.

• Neonatal hypoglycemia.

• Increased risk of T2D later in life for mother and child.

What are the priority nursing interventions for a diabetic patient?

1. Monitor blood glucose regularly.

2. Administer insulin/medications as prescribed.

3. Assess for signs of hypoglycemia/hyperglycemia.

4. Educate patient on diet, exercise, and medication adherence.

5. Monitor for complications (e.g., foot ulcers, infections).

6. Encourage regular follow-ups (HbA1c every 3–6 months).

How do you mix insulin (e.g., NPH + Regular)?

1. Inject air into NPH vial (cloudy) → do not draw up.

2. Inject air into Regular vial (clear) → draw up Regular insulin.

3. Draw up NPH insulin → total dose is now cloudy.

What is the rule of 15 for hypoglycemia?

1. Give 15g fast-acting carbs (e.g., 4 oz juice, 3 glucose tablets).

2. Wait 15 minutes → recheck blood glucose.

3. If still <70 mg/dL, repeat 15g carbs.

4. Once >70 mg/dL, eat a snack or meal.

Key NCLEX Tips

• Never hold insulin without a provider’s order (unless hypoglycemia is present).

• Metformin is held 48 hours before and after contrast dye (risk of lactic acidosis).

• Sulfonylureas (e.g., Glyburide) can cause hypoglycemia → monitor closely.

• SGLT2 inhibitors increase risk of UTIs and dehydration → encourage fluids.

What is the first priority in treating both DKA and HHS?

Fluid resuscitation to restore perfusion and correct dehydration.

What type of IV fluid is used initially for DKA?

• 0.9% Normal Saline (NS) at 1 L/hour if the patient is hypotensive.

• If normotensive, start with 0.9% NS and reassess.

What type of IV fluid is used initially for HHS?

• 0.9% Normal Saline (NS) at 1–2 L in the first hour, even if the patient is normotensive.

• HHS causes more severe dehydration (10–15% fluid deficit).

When should you switch from 0.9% NS to 0.45% NS in DKA?

• After initial fluids, if sodium levels are high or glucose is decreasing.

• Goal: Prevent hypernatremia and cerebral edema.

When should you switch fluids in HHS?

When blood glucose drops to <250 mg/dL, switch to D5 0.45% NS to prevent hypoglycemia while continuing to correct osmolality.

When should IV regular insulin be started in DKA?

• Immediately, even before fluids in some cases.

• Goal: Stop ketosis and lower glucose by 50–75 mg/dL/hour.

What is the initial insulin dose for DKA and HHS?

• Bolus: 0.1 units/kg IV (e.g., 7 units for a 70 kg patient).

• Infusion: 0.1 units/kg/hour (e.g., 7 units/hour for a 70 kg patient).

When should you transition from IV insulin to SQ insulin in DKA?

• When:

  1. Ketones resolve (negative or trace).

  2. Patient can eat.

  3. Blood glucose is stable.

When should you transition from IV insulin to SQ insulin in HHS?

• When:

  1. Mentation improves (patient is alert and oriented).

  2. Blood glucose is stable.

  3. Fluid resuscitation is complete.

Why is potassium replacement critical in both DKA and HHS?

Both conditions cause total body potassium depletion, even if serum K⁺ appears normal/high initially.

When should potassium replacement be started in DKA/HHS?

• Start early, even if serum K⁺ is normal or high.

• Goal: Maintain serum K⁺ between 4–5 mEq/L.

When is bicarbonate used in DKA?

• Only if pH <6.9 (controversial, rarely used).

• Rationale: Severe acidosis can impair cardiac function

Is bicarbonate used in HHS?

No, because HHS does not cause acidosis.

How often should blood glucose be checked in DKA and HHS?

Every hour until stable.

How often should electrolytes (K⁺, Na⁺) be checked in DKA/HHS?

Every 2–4 hours.

What type of diet should be resumed after DKA or HHS?

• Balanced diet with complex carbohydrates, protein, and healthy fats.

• Avoid simple sugars to prevent rebound hyperglycemia.

Which condition has a faster onset?

DKA (hours to days) vs. HHS (days to weeks).