Diabetes Mellitus

Diabetes Mellitus Glycemic Crisis and Care

Key Points

• Diabetes mellitus is chronic hyperglycemia caused by absent insulin, insulin resistance, or both.
• Type 1 diabetes reflects autoimmune beta-cell destruction, while Type 2 diabetes is driven by insulin resistance and relative insulin deficiency.
• Type 2 diabetes accounts for most diagnosed diabetes burden (about 95% of cases), while gestational diabetes can affect up to about 14% of pregnancies.
• Hypoglycemia is blood glucose below 70 mg/dL and requires rapid treatment with carbohydrate and reassessment.
• Severe hyperglycemia can progress to diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS) with life-threatening instability.
• Core nursing priorities are glucose control, complication prevention, and sustained self-management education.
• During stress or infection, blood glucose should be monitored more frequently because glycemic instability risk increases.
• In older adults, avoid overtreatment and consider regimen simplification/deintensification when safe to reduce hypoglycemia and polypharmacy burden.

Pathophysiology

Diabetes mellitus (DM) is a chronic disorder of glucose regulation in which blood glucose remains persistently elevated. Dysfunction of pancreatic islet-cell hormone balance prevents normal insulin-glucagon control and leads to sustained hyperglycemia.

In Type 1 DM, autoimmune injury destroys beta islet cells, producing an absolute insulin deficiency. In Type 2 DM, peripheral tissues become resistant to insulin and pancreatic insulin production becomes insufficient over time. Gestational diabetes occurs during pregnancy and increases later Type 2 DM risk. Latent autoimmune diabetes in adults (LADA) progresses more gradually than classic Type 1 DM.

Classification

• Type 1 DM: Autoimmune beta-cell destruction with little or no endogenous insulin.
• Type 2 DM: Insulin resistance with progressive beta-cell dysfunction.
• Gestational DM: Pregnancy-associated dysglycemia with future Type 2 DM risk.
• LADA: Slowly progressive autoimmune diabetes beginning in adulthood.

Acute Glycemic Emergency Patterns

• DKA profile: More common in T1DM, often develops within about 24 hours, and is commonly associated with glucose above 250 mg/dL, pH 7.3 or lower, ketonemia/ketonuria, and anion gap above about 12 mEq/L.
• HHS profile: More common in T2DM, develops over days to weeks, and is characterized by severe hyperglycemia (commonly above 600 mg/dL), profound dehydration, near-normal pH, and minimal to absent ketosis.
• Mortality contrast: DKA mortality is generally lower, while HHS mortality can be substantially higher in severe presentations.

Nursing Assessment

NCLEX Focus

Prioritize early recognition of hypo- versus hyperglycemia, then escalate quickly for neurologic, hemodynamic, or respiratory deterioration.

• Assess classic hyperglycemia-related manifestations, including polyuria, polydipsia, polyphagia, fatigue, and delayed healing.
• Monitor for hypoglycemia symptoms (confusion, tremor, diaphoresis, tachycardia, anxiety, dizziness, blurred vision), especially in insulin-treated clients.
• Monitor for severe hyperglycemia and crisis cues, including dehydration, altered mentation, hypotension, and potential acidosis signs.
• Monitor skin/wound status because sustained hyperglycemia can worsen perfusion and leukocyte function, delaying wound healing.
• Monitor for severe hyperglycemia cues highlighted at bedside (for example fruity breath odor, warm dry skin, deep rapid breathing) and escalate immediately.
• Distinguish hypoglycemia severity bands: mild below 70 mg/dL, moderate below 40 mg/dL, and severe below 20 mg/dL with inability to swallow, seizure risk, or unconsciousness.
• Treat seizures, inability to eat or drink, or loss of consciousness as emergency hypoglycemia cues requiring immediate rescue escalation.
• Track diagnostic values: fasting glucose 70-100 mg/dL normal; fasting glucose 126 mg/dL or higher on two tests supports DM diagnosis.
• Review HbA1c trends: less than 5.7% normal, 5.7%-6.4% prediabetes, and 6.5% or higher diagnostic for DM.
• Include formal diagnostic alternatives: two-hour value 200 mg/dL or higher during a 75 g OGTT, or random glucose 200 mg/dL or higher with symptomatic hyperglycemia/hyperglycemic crisis.

Illustration reference: OpenRN Health Alterations Ch.7.5.

• Use adjunct diagnostics to clarify phenotype and crisis risk: fasting C-peptide about 0.5-2.0 ng/mL, urine ketone checks when glucose exceeds 240 mg/dL, and urine glucose spillover when serum glucose rises above about 160-180 mg/dL.
• Assess Type 2 DM risk profile for early prevention counseling: prediabetes, overweight/obesity, sedentary pattern, age 45 or older, family history, prior gestational diabetes or macrosomic infant history, and high-risk ethnicity patterns.
• Assess for diabetic-retinopathy progression cues, including blurred vision, floaters, blind spots, color-perception change, and declining visual function.
• Reinforce retinal-monitoring diagnostics when ordered, including dilated eye exam, fundus photography, fluorescein angiography, and OCT trend assessment.

Nursing Interventions

• Implement rapid hypoglycemia response using the 15-15 strategy: give 15 g carbohydrate, recheck glucose in 15 minutes, and repeat until at least 70 mg/dL.
• Follow agency protocol for moderate or severe hypoglycemia, including escalation to glucagon or IV dextrose when swallowing is unsafe; severe episodes may require repeat rescue dosing and ED transfer if consciousness does not recover.
• Reinforce medication adherence for insulin and non-insulin regimens and align timing with meal intake and activity.
• Teach blood glucose monitoring patterns and when to assess ketones, including monitoring when glucose exceeds 240 mg/dL.
• Reinforce detailed glucose logs with routine premeal and bedtime checks when prescribed, and use serial A1c reassessment (often every 3-6 months) for long-term control tracking.
• Provide structured nutrition teaching: distribute carbohydrates evenly (often about 45%-50% of total intake in nonpregnant adult pathways), use lower glycemic-index choices, target protein about 15%-20% of calories, limit saturated fat to less than 10% (or lower when cardiometabolic risk is high), and increase fiber intake.
• Reinforce practical carbohydrate quality guidance: avoid concentrated sucrose and heavily refined processed foods, and prioritize whole-food carbohydrate sources.
• Clarify that very-low-carbohydrate pathways are individualized and are generally avoided in pregnancy/lactation unless specialist-directed.
• When prescribed, reinforce a consistent-carbohydrate meal pattern (similar carbohydrate amount each meal) to reduce hypo/hyperglycemic swings.
• Start diabetes nutrition teaching with a learner assessment (current knowledge, prior experience, readiness, literacy level, preferred learning mode, and cultural/religious food influences) to individualize education.
• Adapt teaching for language and health-literacy needs using qualified medical interpreters, plain-language tools, and teach-back with culturally relevant food examples.
• Teach practical carbohydrate counting for mealtime insulin dosing (15 g carbohydrate equals one carbohydrate choice) and verify understanding with worked meal examples.
• Differentiate carbohydrate-planning methods during teaching: advanced carb counting for intensive insulin regimens (multiple daily injections or pump therapy) versus simpler carbohydrate-choice plans when prescribed.
• Teach the diabetes plate method when appropriate: half non-starchy vegetables, one quarter lean protein, and one quarter carbohydrate foods.
• Include practical diet-self-management topics such as carbohydrate awareness, portion control, personalized meal planning, sugar-substitute selection to reduce added sugars, and label reading focused on carbohydrate/fiber/sugar lines.
• Reinforce use of reliable nutrition references/apps (for example USDA FoodData Central) so clients can estimate carbohydrate grams more accurately.
• Coach exercise planning to reduce glycemic variability: avoid long inactivity gaps, monitor glucose before/during/after activity, and keep fast-acting carbohydrate available to prevent exercise-related hypoglycemia.
• Build affordability-focused self-management plans: low-cost nutrition options, no-cost activity plans, and feasible glucose-monitoring strategies matched to financial constraints.
• Reinforce foot and skin protection and preventive follow-up, including annual eye and podiatry exams, kidney surveillance with microalbumin, blood pressure checks, and lipid monitoring.
• Reinforce frequent foot self-checks and regular professional foot evaluations (often each visit or at least every 3-6 months in high-risk pathways) to reduce ulcer and amputation risk.
• Reinforce microvascular-risk control for vision preservation, including glucose control plus blood pressure and lipid management targets.
• Reinforce early reporting of skin injury in patients with neuropathy because reduced pain sensation can delay treatment and increase infection risk.
• In neuropathy-focused foot care, inspect plantar surfaces and between toes daily, ensure well-fitted footwear and non-irritating sock seams, and report skin breaks early; avoid NA nail trimming in high-risk diabetic feet per facility policy.

Illustration reference: OpenRN Health Alterations Ch.7.5.

• Teach sick-day action planning: check glucose at least every 4 hours, maintain hydration, test urine ketones every 4-6 hours when indicated, and escalate for persistent vomiting/diarrhea or fever.
• During infection or acute physiologic stress, increase blood glucose surveillance frequency and proactively reassess medication timing/intensity.
• In unstable inpatient glycemic windows, oral agents may be temporarily held while insulin-based regimens are titrated to reduce rapid fluctuations.
• Connect patients and families (with consent) to community supports such as medication-assistance programs, sliding-scale clinics, food resources, and telehealth-friendly follow-up when transportation or work schedules limit access.
• Refer high-risk adults with prediabetes to structured diabetes-prevention programs (for example CDC-recognized lifestyle-change coaching and peer-support pathways) to reduce progression to Type 2 diabetes.
• In older adults, review for overtreatment at routine visits and consider deintensifying complex regimens when individualized A1C targets can still be met.
• Use A1C trend review as a treatment-effectiveness checkpoint and adjust plan when persistent elevation indicates poor control/adherence mismatch.

Glycemic Emergency Progression

Uncontrolled glucose abnormalities can rapidly progress to seizure, coma, arrhythmia, shock, or death without prompt treatment and escalation.

Pharmacology

Drug Class	Examples	Key Nursing Considerations
insulin	class-based insulin regimens	Match dosing with meals/activity and monitor for hypoglycemia.
biguanides	metformin	Give with meals in divided doses; avoid in metabolic acidosis and significant renal/hepatic dysfunction; hold around iodinated contrast studies and monitor for subtle lactic acidosis cues (malaise, myalgias, dyspnea, somnolence, abdominal distress).
sulfonylureas	glipizide, glyburide, glimepiride	Dose about 30 minutes before meals; severe hypoglycemia risk is higher in older adults and may be harder to recognize with beta-blockers; avoid in Type 1 DM/DKA and monitor for drug interactions (e.g., NSAIDs/protein-bound drugs) and alcohol disulfiram-like reactions.
DPP-4 inhibitors	sitagliptin, saxagliptin	May be taken with or without food; monitor for hypersensitivity, severe arthralgia, pancreatitis symptoms, heart-failure worsening, and blistering/erosive skin reactions.
GLP-1 receptor agonists	class-based injectables	Improve glycemic control and satiety; reinforce administration steps.

Clinical Judgment Application

Clinical Scenario

A client with Type 2 DM has increasing thirst, frequent urination, fatigue, and random glucose values repeatedly above goal after recent illness and poor intake.

• Recognize Cues: Persistent hyperglycemia symptoms with dehydration risk.
• Analyze Cues: Current regimen and self-management are insufficient during acute stress.
• Prioritize Hypotheses: Highest priority is preventing progression to hyperglycemic crisis.
• Generate Solutions: Intensify monitoring, implement provider-ordered medication adjustment, and reinforce sick-day guidance.
• Take Action: Reassess glucose trends, hydration status, and mental status; escalate concerning findings promptly.
• Evaluate Outcomes: Glucose trends improve, hydration stabilizes, and no DKA/HHS transition occurs.

Related Concepts

• metabolic-syndrome-and-adult-chronic-disease-risk - Shared risk-pattern context for Type 2 diabetes progression.
• hypertension-assessment-and-management - Common comorbidity that accelerates vascular injury in DM.
• peritoneal-and-hemodialysis-nursing-management - Relevant when diabetic nephropathy progresses to kidney failure.
• Hyperosmolar hyperglycemic state (HHS) - Severe Type 2 hyperglycemic emergency with profound dehydration risk.
• Diabetic ketoacidosis (DKA) - High-risk metabolic emergency associated with insulin deficiency and acidosis.

Self-Check

1. Which glucose and HbA1c thresholds distinguish normal, prediabetes, and diabetes ranges?
2. How does the 15-15 hypoglycemia approach reduce immediate neurologic risk?
3. Which assessment findings should prompt concern for progression to DKA or HHS?