Medical Emergencies · patient case question
During adult CPR, what is the minimum compression depth?
Patient case: Three Emergencies in One Afternoon
Patient: Three separate patients seen the same afternoon
Chief Complaint: (1) A crown slipped from the forceps and the patient swallowed it. (2) A patient's blood pressure reads 180/120 mmHg at screening. (3) A patient has a generalised seizure lasting seven minutes.
Background: Patient 1: routine crown cementation, coughed once then settled. Patient 2: known hypertensive, took no medication this morning, asymptomatic. Patient 3: known epilepsy, missed his medication.
Medications: Patient 2: amlodipine. Patient 3: levetiracetam.
Vital Signs: Patient 1: SpO₂ 99%, RR 16, speaking in full sentences. Patient 2: BP 180/120 mmHg confirmed on repeat, HR 88. Patient 3: post-ictal, then becomes cyanotic.
Findings: Patient 1: no stridor, no wheeze, no distress. Patient 2: no chest pain, no headache, no visual change, no neurological deficit. Patient 3: recovered consciousness briefly, then developed central cyanosis.
Show answer and explanation
Correct answer: A. At least 2 inches (5 cm)
- A. CORRECT. Current AHA guidance specifies compressions of AT LEAST 2 INCHES (5 cm) in an adult, and not more than 2.4 inches (6 cm), at a rate of 100–120 per minute, allowing full chest recoil between compressions and minimising interruptions. In children compress about one-third of the chest depth, roughly 2 inches; in infants roughly 1.5 inches.
- B. 1 inch is grossly inadequate in an adult and generates almost no cardiac output.
- C. 3 inches exceeds the recommended maximum and risks rib fractures and visceral injury.
- D. 1.5 inches is the INFANT depth. Applied to an adult it will not perfuse the brain or myocardium.
Note: ⚑ SOURCE ERROR. The recall recorded 1.5 inches. The adult figure is AT LEAST 2 INCHES — please correct this in the group file, as it is a potentially consequential error. Compression-to-ventilation ratio is 30:2 for single-rescuer adult CPR.
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