Are there any studies about the efficacy of this technique. Or even, you know, a reputable source for it?
A bit of googling shows it is widely discussed and was once in CPR guidelines (but isn't any more). https://pubmed.ncbi.nlm.nih.gov/34034775/ is a recent randomized trial that found no improvement.
alt Hacker News
A bit of googling shows it is widely discussed and was once in CPR guidelines (but isn't any more). https://pubmed.ncbi.nlm.nih.gov/34034775/ is a recent randomized trial that found no improvement.