Very briefly sharing about the topic in Brazil (referencing the articles, if I or someone decide to plan a full show about...):

× One is not obliged to soccur another if not responsible or part of the damaging or dangerous act (e.g., a car crash) or by law responsible for the person (parents in relation to their under age children, e.g.). 
[art. 13, § 2º of CP, Brazilian Criminal Code, and art. 176, I of CTB, Brazilian Traffic Code.]

✓ Exception: Art. 135 of Criminal Code: it's crime to: "Failing to provide assistance, when possible without personal risk, to an abandoned or lost child, or to an invalid or injured person who is helpless or in grave and imminent danger, or failing to call for help from public authorities in such cases". (It's law, but dead letter, not applied effectively. In fact it's the general rule above.

✓ If you help someone, except in the cases you are responsible for the event itself, you don't have to pay and are not responsible for damages eventually caused for helping in good faith and in the best practice that would be reasonably expected.
[Article 188 of Código Civil (CC) brasileiro, the Brazilian Civil Law].
As I'm not exactly in the area, but Law in general, searching here for exemplification on the classical example (CPR maneuver), I found a decision from the São Paulo state Court of Justice ["Apelação Cível 0079954-88.2012.8.26.0224; judge: Luciana Bresciani, 2023-09-01], deciding: "Hepatic and bone injuries possibly resulting from cardiopulmonary resuscitation maneuvers – Lack of proof of defective provision of medical services". So, even doctors, if not *proved* guilty (malpractice, for example), is not liable for some undesirable but common results of procedures.