Confusion / Delirium OSCE - Hypoglycemia

Case Overview

• Age/Sex: 68-year-old female
• Occupation: Retired primary school teacher
• Setting: Brought to ED by neighbour/family from home
• Chief complaint: "Confused and not themselves"

Patient Script

Who I Am

I'm 68, a retired schoolteacher who lives alone but has neighbours who check on me.

What Brings Me In

I woke up feeling funny this morning — dizzy and sweaty — and then my neighbour says I was confused and not acting like myself, so she brought me in.

My Story

I started feeling off this morning, about 6 hours ago — I was shaky and sweaty, and a bit light-headed after I missed breakfast. For the last few hours I’ve been confused and forgetful, could not remember where I put the kettle, and my neighbour says I kept repeating myself. I felt better for a few minutes after sipping tea, but then I got worse again and seemed very sleepy and hard to wake a couple of times, so she called for help. I also had diarrhoea for two days last week (I thought it was a bug) and I bumped my head on the bathroom door last month after a small fall — nothing major. Oh — and I started a new sleeping tablet a week ago that my GP prescribed.

My Medical Background

• Type 2 diabetes for 14 years
• Chronic kidney disease (stage 3)
• Hypertension
• Atrial fibrillation (rate controlled)
• Medications:
  • Insulin glargine 20 units nightly
  • Insulin aspart 6 units before meals (usually breakfast & dinner)
  • Lisinopril 10 mg daily
  • Warfarin (for AF)
  • Zopiclone 7.5 mg at night (started 1 week ago)
  • Atorvastatin 20 mg at night
• Allergies: none known
• Social: lives alone, independent with ADLs, has a neighbour who checks in; drinks 1–2 glasses of wine most nights; ex-smoker (quit 10 years ago)
• Family: daughter lives nearby; mother had dementia

What I Think & Worry About

• I think maybe I had a stroke because I suddenly couldn’t think straight.
• I worry I’m losing my memory and won’t be able to look after myself.
• I worry I’ve taken something wrong with my pills — or that the new sleeping tablet is making me muddled.

If You Ask Me About Other Symptoms...

• Head: "A bit of a headache this morning, but not bad."
• Weakness/numbness: "No, I didn’t have one-sided weakness — I just kept repeating myself."
• Vision/speech: "My speaking was a bit slurred once, but it came and went."
• Chest pain/breathing: "No chest pain, breathing okay."
• Fever/ infection symptoms: "No fever — but I had a bit of a urine burning feeling a couple of weeks ago, I used some leftover antibiotics, but that stopped." (red herring)
• Food intake: "I skipped breakfast because I wasn’t hungry and I forgot to eat after I felt sweaty." (important)
• Alcohol: "I had a glass of wine last night, maybe two, but nothing unusual." (potential red herring)

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Clinical Summary

Examination

• General: drowsy but arousable, intermittently confused
• GCS: 9/15 (E2 V2 M5)
• Vitals: BP 100/58 mmHg, HR 112 bpm (sinus tachycardia), RR 18/min, SpO2 97% on room air, Temp 36.4°C
• Skin: cool, clammy and diaphoretic
• Cardiovascular: tachycardic, no murmurs, no peripheral oedema
• Respiratory: clear lungs bilaterally
• Abdomen: soft, non-tender
• Neurological: no focal lateralising signs on brief exam; pupils equal and reactive; symmetric power in all limbs when examined; speech intermittent and slurred when drowsy

Investigations

• Point-of-care capillary glucose: 1.9 mmol/L (34 mg/dL) (severe hypoglycaemia)
• Venous glucose: 2.1 mmol/L (38 mg/dL) (confirms hypoglycaemia)
• Electrolytes: Na+ 138 mmol/L (normal), K+ 3.1 mmol/L (mild hypokalaemia), Cl- 102 mmol/L
• Urea/Creatinine: urea 9.5 mmol/L, creatinine 130 µmol/L (baseline ~110) (eGFR ≈ 38 mL/min/1.73m2)
• Capillary ketones: negative/trace (argues against starvation/ketotic hypoglycaemia)
• Blood gas (venous): pH 7.35, lactate 1.8 mmol/L (normal), glucose 2.0 mmol/L
• HbA1c: 56 mmol/mol (7.3%) (moderate control)
• FBC: WCC 8.2 x10^9/L, Hgb 128 g/L, platelets 230 x10^9/L
• INR: 2.4 (on warfarin)
• ECG: sinus tachycardia, no acute ischemic changes
• CXR: clear
• (If available later) Serum insulin/C-peptide and sulfonylurea screen: pending

Diagnosis

Primary diagnosis:

• Severe hypoglycaemia causing confusion and reduced consciousness, most likely due to insulin therapy in the context of decreased oral intake and reduced renal clearance (CKD), supported by very low capillary and venous glucose, history of missed meals, and ongoing insulin regimen.

Differential diagnoses and reasoning:

• Acute stroke or transient ischaemic attack — considered due to acute confusion and slurred speech, but unlikely because of global symptoms without focal deficit and the presence of severe hypoglycaemia which explains the neurological state.
• Sepsis (e.g., UTI) causing delirium — afebrile, normal WCC, and no localising signs; prior urinary symptoms noted but unlikely to be primary cause of sudden severe confusion.
• Drug-induced delirium (e.g., new zopiclone or alcohol intoxication) — possible contributor, but the profound hypoglycaemia on testing is a more immediate explanation.
• Insulinoma or sulfonylurea overdose — less likely in acute setting given recent missed meals and current insulin use; sulfonylurea still possible if co-prescribed but patient not taking them currently (a screen can clarify).

Management

• Immediate:
  • ABCs and ensure airway protection given reduced GCS; place patient in lateral position and prepare to secure airway if no improvement.
  • Give 50% dextrose 50 mL IV bolus (or 20 mL of 50% dextrose depending on local protocol) immediately; if no IV access, give 1 mg glucagon IM.
  • Re-check capillary glucose after 10 minutes and repeat dextrose if glucose remains <4.0 mmol/L or patient remains symptomatic.
• Short term/hospital:
  • Continuous cardiac monitoring and frequent glucose checks (q15 min until stable, then q1h for several hours).
  • Establish cause: review insulin dosing and timing, review meal pattern, check renal function and medication reconciliation (look for sulfonylureas, recent dosing errors)
  • If sulfonylurea suspected, consider octreotide to prevent recurrent hypoglycaemia.
  • Correct electrolytes (e.g., replete potassium carefully if needed) and monitor INR given warfarin therapy.
  • Admit for observation until stable and alert with normalizing glucose; involve endocrinology or diabetes team for insulin regimen adjustment and education.
  • Social assessment: capacity, home support, and consideration of increased community support or supervised care if recurrent hypoglycaemia risk.
• Longer term:
  • Review and simplify diabetes regimen in elderly with CKD (consider reducing insulin doses or switching regimens), provide education on sick-day rules and recognition/treatment of hypoglycaemia, arrange follow-up with diabetes clinic.

Key Learning Points

• Always check a capillary blood glucose early in any patient with altered mental status or suspected stroke — hypoglycaemia is a reversible mimic.
• Elderly patients with diabetes and renal impairment are at higher risk of severe hypoglycaemia when using insulin; assess meals, recent illnesses, and medication changes as precipitants.
• Acute management requires rapid glucose replacement, reassessment, monitoring for recurrence, and identifying the underlying cause to prevent future episodes.