How should I assess the effectiveness of basic life support (BLS) techniques during a cardiac arrest situation?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 22 August 2025Updated: 22 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Assessing the effectiveness of basic life support (BLS) techniques during a cardiac arrest involves continuous monitoring of key physiological and procedural indicators. Effective BLS is primarily assessed by the quality of chest compressions—depth, rate, and minimal interruptions—as these directly influence patient outcomes . Observing for signs of return of spontaneous circulation (ROSC), such as the presence of a palpable pulse, spontaneous breathing, and improved skin colour, is critical during resuscitation attempts . Additionally, the use of automated external defibrillators (AEDs) and timely defibrillation, when indicated, enhances survival chances and serves as an indirect measure of effective BLS .

Continuous feedback devices, where available, can objectively measure compression quality, providing real-time data on compression depth and rate, which improves the effectiveness of BLS . Layperson training studies emphasize that skill retention and performance during actual resuscitation are improved by regular practice and feedback, which correlates with better patient survival .

In specific populations such as paediatric or obstetric cardiac arrest, tailored BLS protocols and assessment criteria are recommended to ensure effectiveness, as highlighted by recent clinical trials . Overall, the assessment of BLS effectiveness is a dynamic process combining clinical signs of patient response, procedural quality metrics, and adherence to guideline-based protocols .

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