Diabetes: Monitoring, crisis, safety, and counseling

What are the 2 main methods of blood glucose monitoring (BGM)?

Glucose meter and continuous glucose monitor (CGM)

How does a CGM measure glucose?

A sensor/probe enters fatty tissue and measures glucose in the interstitial fluid between cells

What additional glycemic-control metric does a CGM provide?

Percent time in range

When should a glucose meter be recalibrated if calibration is required?

When opening a new test-strip canister, after extreme heat/cold exposure, after dropping the meter, or when the BG reading does not match how the patient feels

How should glucose meter test strips be stored?

In the original container with the cap closed and protected from light and air

What are the basic steps for testing BG with a glucose meter?

Insert test strip → prick side of fingertip → apply blood to strip → record result → discard lancet in sharps container

What are possible alternative sites for blood glucose testing, and hen would these be appropriate to use?

Forearm, palm, and thigh; Only when BG is stable

Why should alternative-site testing be avoided when BG is changing rapidly?

Readings can lag behind fingertip measurements by up to 20 minutes

When should alternative-site BG testing NOT be used?

After eating, after exercise, when BG is changing quickly, or when hypoglycemia is suspected

What BG level defines hypoglycemia?

BG <70 mg/dL

What are common symptoms of hypoglycemia?

Dizziness, shakiness, anxiety/irritability, confusion, tremors, palpitations/tachycardia, sweating, hunger, nausea, headache, ataxia, and blurred vision

What can severe hypoglycemia cause?

Seizures, coma, and death

What serious consequences can result from hypoglycemia?

Falls, motor vehicle accidents, severe neurologic effects, and death

Why is preventing recurrent hypoglycemia especially important?

Each episode contributes to irreversible cognitive impairment

How is hypoglycemia treated in a conscious patient who can swallow?

Use the Rule of 15: give 15 g glucose/carbohydrate → recheck BG in 15 min → repeat if still low → once normal, eat a small meal or snack

What type of carbohydrate is preferred for treating conscious hypoglycemia?

Pure glucose (tablets or gel); other glucose-containing carbohydrates can also be used

Why should high-fat foods such as chocolate candy bars not be used to treat hypoglycemia?

Fat slows glucose absorption and prolongs hypoglycemia

What are examples of approximately 15 g of carbohydrate for treating hypoglycemia?

4 oz (1/2 cup) juice; 8 oz (1 cup) milk; 4 oz regular soda; 1 Tbsp sugar/honey/corn syrup; 3–4 glucose tablets or 1 serving glucose gel

How should severe hypoglycemia be treated when a patient is unconscious or unable to take oral treatment?

IV dextrose if IV access is available OR glucagon if oral treatment/IV dextrose is not possible

What position should an unconscious patient receiving glucagon be placed in?

Lateral recumbent (on their side) to protect the airway and prevent choking when consciousness returns

What is the primary cause of drug-induced hypoglycemia?

Insulin

Why are sulfonylureas generally not recommended in older adults according to Beers Criteria?

High risk of hypoglycemia

How does alcohol affect hypoglycemia risk with insulin or sulfonylureas?

increases the risk of hypoglycemia

How do beta-blockers affect hypoglycemia in patients using insulin or sulfonylureas?

They can enhance hypoglycemic effects and mask some warning symptoms

Which hypoglycemia symptoms may be masked by beta-blockers, and which may remain?

Shakiness, palpitations, and anxiety may be masked; sweating and possibly hunger may remain

Which major drug classes can increase blood glucose?

Thiazide/loop diuretics,

calcineurin inhibitors,

protease inhibitors,

antipsychotics,

statins,

systemic steroids,

beta-agonists,

systemic azole antifungals,

cough syrups,

and niacin

Which drugs can cause either hypoglycemia OR hyperglycemia?

Beta-blockers, fluoroquinolones, and octreotide

Which drugs can cause hypoglycemia?

Beta-blockers,

fluoroquinolones,

tramadol,

linezolid,

octreotide,

pentamidine,

quinine

When should persistent inpatient hyperglycemia generally be treated?

BG ≥180 mg/dL

What is the target BG range for most noncritically ill hospitalized patients?

100–180 mg/dL

What is the target BG range for critically ill ICU patients?

140–180 mg/dL

Why is sliding-scale insulin (SSI) alone discouraged for inpatient BG control?

It is reactionary, can lead to poor outcomes, and is usually not patient-specific

What primarily determines the inpatient insulin regimen?

The patient's oral intake

What inpatient insulin regimen is preferred when oral intake is adequate?

Basal + prandial (bolus) + correction insulin

What inpatient insulin regimen is recommended when a patient has poor oral intake?

Basal + correction insulin without prandial insulin

What insulin regimen is recommended for critically ill patients?

Continuous IV insulin infusion

In which patients does DKA most commonly occur?

Patients with T1DM, although it can also occur in T2DM

What can precipitate DKA?

Insulin omission/nonadherence or subtherapeutic insulin from increased requirements during a stressor such as infection

Why are ketones produced in DKA?

Low/absent insulin + high glucagon causes triglycerides → FFAs → hepatic ketone production

What are the key diagnostic findings of DKA?

BG ≥200 mg/dL (or history of diabetes) + ketones + metabolic acidosis

What acid-base findings are characteristic of DKA?

Arterial pH <7.3 and/or bicarbonate <18 mEq/L; most patients have anion gap >12

What signs and symptoms can result from ketone production in DKA?

Fruity breath, abdominal pain, nausea/vomiting, and dehydration

Which diabetes type is HHS most commonly associated with?

T2DM

How does the mortality of HHS compare with DKA?

HHS has a higher mortality rate but is less common

What commonly precipitates HHS?

Illness such as infection or stroke → reduced fluid intake + osmotic diuresis → severe dehydration

What are the key diagnostic findings of HHS?

BG ≥600 mg/dL + serum osmolality >320 mOsm/L + extreme dehydration + little/no acidosis + no ketones

What neurologic symptoms are characteristic of HHS?

Altered consciousness, including confusion and delirium

What acid-base findings are expected in HHS?

pH ≥7.3 and bicarbonate ≥15 mEq/L

Why are ketones generally absent in HHS?

Patients with T2DM usually produce enough insulin to suppress significant ketone formation

How can severe hyperglycemia affect serum sodium?

It can decrease measured sodium and may require sodium correction in DKA or HHS

What is the FIRST treatment for both DKA and HHS?

Aggressive IV fluids (normal saline)

When should dextrose be added to IV fluids during DKA/HHS treatment?

When BG <250 mg/dL; add D5W or D10W

What insulin is used for continuous IV treatment of DKA and HHS?

Regular insulin

What is the regular insulin regimen for DKA?

0.1 units/kg IV bolus → 0.1 units/kg/hr continuous infusion

What is the regular insulin infusion rate for HHS?

0.05 units/kg/hr continuous infusion

What serum potassium range should generally be maintained during DKA/HHS treatment?

4–5 mEq/L

What is the basic treatment sequence for DKA/HHS?

IV fluids first → regular insulin → monitor/replace K+ → add dextrose when BG <250 mg/dL

When may sodium bicarbonate be considered in DKA?

If pH <7

How may sulfonylureas need to be managed during acute illness in a diabetic patient?

Reduce the dose or discontinue due to increased hypoglycemia risk

Which antimicrobials can further increase hypoglycemia risk with sulfonylureas during illness in a diabetic patient?

Fluoroquinolones and clarithromycin

Which diabetes medications should be considered for holding during acute illness with dehydration or kidney-injury risk?

SGLT2 inhibitors and metformin

Why may SGLT2 inhibitors and metformin be held during acute illness?

Concern for dehydration and acute kidney injury

Which diabetes medications may need to be held during gastrointestinal illness?

GLP-1 agonists and GLP-1/GIP agonists

Should basal insulin be stopped during acute illness in T1DM?

No; basal insulin should NOT be stopped even if the patient is eating less

Should basal insulin routinely be stopped during acute illness in T2DM?

No; it generally should not be stopped even with reduced oral intake

Why is continued basal insulin especially important during illness in T1DM?

Stopping basal insulin can lead to severe insulin deficiency and DKA

Which diabetes medications should be avoided with bladder cancer?

TZDs (actos)

Which diabetes medications should be avoided with thyroid cancer, including medullary thyroid carcinoma?

GLP-1 agonists and GLP-1/GIP agonists

Which diabetes medications should be avoided with gastroparesis or GI disorders?

GLP-1 agonists, GLP-1/GIP agonists, and pramlintide

Which diabetes medications should be avoided with genital infections or UTIs?

SGLT2 inhibitors

Which diabetes medications should be avoided with heart failure?

TZDs, alogliptin, and saxagliptin

Which diabetes medications should be avoided with hypoglycemia?

Insulin, sulfonylureas, meglitinides, and pramlintide

Which diabetes medications should be avoided with hypotension or dehydration?

SGLT2 inhibitors

Which diabetes medication should be avoided with hypokalemia?

Insulin

Which diabetes medications should be avoided with a history or risk of ketoacidosis?

SGLT2 inhibitors; ketoacidosis can occur even when BG <250 mg/dL

Which diabetes medication should be avoided with lactic acidosis risk?

Metformin; risk increases with renal impairment and alcohol use disorder

Which diabetes medications should be avoided with osteopenia or osteoporosis?

Canagliflozin and bexagliflozin (↓ BMD/fractures) and TZDs (fractures)

Which diabetes medications should be avoided with pancreatitis?

DPP-4 inhibitors, GLP-1 agonists, and GLP-1/GIP agonists

Which diabetes medications should be avoided with peripheral neuropathy, PAD, or foot ulcers?

Canagliflozin and bexagliflozin

Which diabetes medications should be avoided or used cautiously with a severe sulfa allergy?

Sulfonylureas

Which diabetes medications should be avoided with renal insufficiency (eGFR or CrCl <30 mL/min)?

Metformin, exenatide, and glyburide

Which diabetes medications should be avoided with weight gain or obesity?

Sulfonylureas, meglitinides, TZDs, and insulin

How should exenatide be administered?

Within 60 minutes before meals

How should oral semaglutide (Rybelsus) be taken?

30 minutes before breakfast

Which GLP-1/GLP-1-GIP agonists are injected once weekly?

Trulicity, Ozempic, and Mounjaro

Which GLP-1 agonist products require pen needles to be purchased separately?

Exenatide and Victoza

What should a patient do before using a refrigerated GLP-1/GLP-1-GIP injection?

Allow it to reach room temperature for 15 minutes

What are the key GI and weight effects of GLP-1/GLP-1-GIP agonists?

Nausea, vomiting, diarrhea, decreased appetite, and weight loss

What serious adverse effects should patients using GLP-1/GLP-1-GIP agonists know?

Pancreatitis, gallbladder disease, and kidney damage from dehydration due to severe vomiting/diarrhea

Which GLP-1/GLP-1-GIP products are associated with diabetic retinopathy complications?

Ozempic, Mounjaro, and Trulicity

What important adverse effects should patients taking SGLT2 inhibitors be counseled about?

Hypotension, ketoacidosis, severe UTIs, and genital fungal infections

What should patients taking SGLT2 inhibitors know about surgery?

Stop the medication prior to surgery to reduce ketoacidosis risk

Which SGLT2 inhibitors have an amputation/fracture warnings?

Canagliflozin and bexagliflozin; avoid with foot problems or neuropathy

What serious adverse effect is associated with metformin?

Lactic acidosis

What supplementation may be needed with long-term metformin therapy?

Vitamin B12

What are the major adverse effects of TZDs?

Heart failure/worsening HF, weight gain, and bone fractures

What are the major adverse effects of DPP-4 inhibitors?

Pancreatitis and severe arthralgia

Which DPP-4 inhibitors are associated with heart failure?

Saxagliptin and alogliptin

How should most sulfonylureas be taken relative to meals?

With breakfast

How should immediate-release glipizide be taken?

30 minutes before meals