Simulated Patient Scenario

Hyperkalaemia

Scenario Details

Scenario: Suspected Hyperkalaemia

Simulated Patient: 68-year-old Male

Actor/Actress: Student Actor (Patient), Student Actor (Wife)

MDT Information

Urgent Response - Collapse / Cardiac Problem
68-year-old male, feeling generally unwell, weak, now collapsed
History of kidney problems
Patient is conscious but very weak
Location: Home address

On Arrival

You arrive at a house where the patient's anxious wife meets you. She leads you to the living room where the patient, a 68-year-old male, is lying semi-recumbent on the sofa. He appears pale, lethargic, and generally unwell. He is conscious and makes eye contact but seems profoundly weak. His breathing appears slow.

Initial Impression and Primary Survey

Category	Finding
Initial Impression	Acutely unwell, lethargic, pale, potentially unstable.
Response	Opens eyes to voice, responds verbally but speech is slow and weak. (AVPU = V)
Airway	Clear and self-maintaining.
Breathing	Slow respiratory rate, normal to shallow depth.
Circulation	Pale, cool peripheries. Weak radial pulse, markedly slow rate (bradycardia). Hypotensive.
Disability	Lethargic, profound generalised weakness.
Exposure/Environment	Indoor home environment. Patient wearing day clothes. Check for dialysis access (e.g., fistula/graft in arm), medication boxes.

Secondary Survey and Simulation Progression

History (obtained from patient - difficult due to weakness, and wife)

Allergies	NKDA
Medications	Ramipril, Spironolactone, Bisoprolol, Frusemide, Atorvastatin, Aspirin. Wife unsure if he takes potassium supplements, denies recent changes.
Past Medical History	End-Stage Renal Failure (ESRF) on haemodialysis (3 times/week), Hypertension, Heart Failure (moderate LV impairment), Type 2 Diabetes Mellitus (diet controlled).
Last Oral Intake	Breakfast ~4 hours ago. Poor appetite recently.
Events Preceding	Patient missed his scheduled dialysis session yesterday due to feeling unwell (nausea, fatigue). Felt progressively weaker overnight and today. Complained of muscle weakness and feeling 'heavy'. Collapsed onto sofa about 30 minutes ago, unable to stand since. Wife denies chest pain, but patient seems too weak to articulate symptoms clearly.

Vital Signs/Assessment (Initial)

Parameter	Value
Resp. Rate (/min.)	10 (slow, shallow)
Lung Sounds (L/R)	May have basal crackles (consistent with fluid overload/HF).
SpO2 (%)	95% (Room Air)
EtCO2 (mmHg)	May be slightly elevated due to hypoventilation, or normal/low if metabolic acidosis present.
Pulse Rate (/min.)	38, regular but weak
CRT (sec.)	4 sec
ECG rhythm	Severe Bradycardia. Potential for Sine Wave pattern / Ventricular Rhythms / Asystole.
12-lead ECG	CRITICAL FINDING: Peaked T waves, widened QRS complex, flattened/absent P waves, prolonged PR interval. Possible sine wave pattern.
BP (mmHg)	80/50 (Hypotensive)
Skin	Pale, cool, clammy peripheries.
Pain (/10)	Denies pain, reports profound weakness.
GCS (/15: E,V,M)	12-13/15 (E3, V4-5 weak/slow, M5-6 weak)
BGL (mmol/L)	6.8 (Can be variable in hyperkalaemia)
Pupils (mmL/mmR)	3mm L / 3mm R, Equal and Reactive (PERL)
Temp. (°C)	36.4 (May be normal or low)

Physical Examination

General Appearance: Acutely unwell, lethargic, pale, profoundly weak.
Cardiovascular: Severe bradycardia, hypotension. Weak peripheral pulses. Check for JVD, peripheral oedema (signs of fluid overload/HF).
Respiratory: Bradypnoea, potentially shallow. Basal crackles may be present.
Neurological: Lethargic, GCS 12-13. Marked generalised muscle weakness (difficulty lifting limbs). Reflexes may be diminished.
Other: Assess dialysis fistula/graft if present (check for thrill/bruit). Skin may show signs of uraemia (e.g., excoriations).

Assessment and Treatment

Appropriate Management Focus

Primary Survey (ABCDE): High index of suspicion for hyperkalaemia based on history (ESRF, missed dialysis, medications) and clinical signs (bradycardia, weakness, ECG changes). Prepare for potential cardiac arrest.
ECG Acquisition & Interpretation: **Obtain 12-lead ECG IMMEDIATELY.** Recognize characteristic hyperkalaemia changes (peaked T waves, wide QRS, bradycardia, etc.). This is critical for diagnosis and guiding treatment.
Oxygen Therapy: Apply high-flow oxygen via non-rebreather mask due to critical illness, potential hypoventilation, and shock state. Assist ventilations if necessary (BVM).
Vascular Access: Establish large-bore IV access urgently.
Cardiac Membrane Stabilisation: If ECG changes consistent with hyperkalaemia are present:
- Administer **Calcium Chloride** or **Calcium Gluconate** IV according to local protocols. This is the priority treatment to prevent fatal arrhythmias.
Potassium Shift Therapy (Second line, after Calcium if indicated):
- Administer high-dose nebulised **Salbutamol** (check local protocols for dose).
- (Insulin/Dextrose is typically an in-hospital treatment, rarely given prehospital unless specific protocols exist).
Fluid Therapy: Administer IV fluids (e.g., Sodium Chloride 0.9%) cautiously. Bolus if clearly hypotensive/shocked, but be mindful of potential fluid overload in ESRF/HF patients. Titrate to BP response.
Sodium Bicarbonate: Consider IV Sodium Bicarbonate if prolonged resuscitation, severe acidosis suspected, and per local protocols (controversial, usually after other measures).
Monitoring: Continuous ECG monitoring is essential. Frequent vital signs reassessment (every 5 mins or less). Monitor mental status, respiratory effort.
Treat Reversible Causes (Cardiac Arrest): If arrest occurs, follow standard ALS guidelines, but strongly consider hyperkalaemia as the cause and administer Calcium early.
Transport: **Urgent transport** to an ED capable of managing hyperkalaemia and providing emergency dialysis. Pre-notify receiving hospital (CRITICAL PATIENT: Suspected severe hyperkalaemia with ECG changes/haemodynamic instability, treatments given).
Teamwork & Communication: Clear roles, closed-loop communication. Anticipate deterioration. Calm communication with wife. Clear, concise handover.

Debrief Focus Points

Recognizing risk factors and clinical presentation of hyperkalaemia.
Critical importance of early 12-lead ECG acquisition and interpretation for hyperkalaemia.
Understanding the mechanism and priority of treatments: Cardiac membrane stabilisation (Calcium) vs. Potassium shift (Salbutamol).
Appropriate fluid management in ESRF patients with suspected hyperkalaemia.
Anticipating and managing cardiac arrest in hyperkalaemia.
Importance of pre-notification and transport to an appropriate facility (dialysis capability).
Teamwork and managing a critically unwell patient.