242. Therefore, the State failed to comply with the obligation to provide the presumed victim with accessible medical care, which constituted a violation of the rights to health and to personal integrity, established in Articles 26 and 5 of the American Convention. B.5 The violation of the right to life and the alleged lack of investigation 243. The Court has indicated that, to determine the international responsibility of the State in cases of death in a medical context, the following must be proved: (a) that due to acts or omissions, a patient is denied access to health care in situations of medical emergencies or essential medical treatments, despite the foreseeable risk that this denial signifies for the patient’s life, or (b) gross medical negligence, 392 and (c) the existence of a causal nexus between the action that has been proved and the harm suffered by the patient.393 When the attribution of responsibility stems from an omission, it is necessary to verify the probability that the omitted conduct would have interrupted the causal process that brought about the harmful result. This verification must take into consideration any possible situation that indicated the special vulnerability of the person concerned, 394 such as the fact that they were in prison, and on this basis the measures adopted to protect them. 395 244. In this case, the Court notes that Manuela died on April 30, 2010. The cause of her death was cardiorespiratory arrest and the diagnosis was Hodgkin’s lymphoma.396 According to expert witness Guillermo Ortiz: Hodgkin’s lymphoma is one of the cancers that have the most favorable outcome when they are detected in time. That is to say, they can be 95% cured if they are detected in time. Unfortunately, in the case of [Manuela] it was detected belatedly and the treatment was too late and, therefore, it was not effective.397 245. The Court has verified various omissions in the medical attention provided to the presumed victim. Specifically, the State failed to comply with its obligations: (i) to perform a comprehensive examination of Manuela’s health when she was hospitalized; (ii) to examine her health at the time she was detained, and (iii) to take the necessary measures to ensure that Manuela could receive medical treatment while she was deprived of liberty. If these omissions had not occurred, the probability that Manuela would die due to Hodgkin’s lymphoma would have been reduced. Accordingly, the Court considers that the existence of a causal nexus in this case has been proved, and this demonstrates the failure to comply with the obligation to ensure Manuela’s right to life. 246. Consequently, the State is responsible for the violation of the obligation to ensure the right to life contained in Article 4(1) of the American Convention in relation to Article 1(1) of this instrument. 247. The Court has also established that when a person dies while in the State’s custody, the pertinent authorities have the duty to open, ex officio and immediately, a serious, impartial Cf. Case of Ximenes Lopes v. Brazil, supra, paras. 120 to 122, 146 and 150, and Case of Cuscul Pivaral et al. v. Guatemala, supra, para. 156. 392 Case of Poblete Vilches et al. v. Chile, supra, para. 148, and Case of Cuscul Pivaral et al. v. Guatemala, supra, para. 156. 393 Cf. Case of the Xákmok Kásek Indigenous Community v. Paraguay. Merits, reparations and costs. Judgment of August 24, 2010. Series C No. 214, para. 227, and Case of Cuscul Pivaral et al. v. Guatemala, supra, para. 156. 394 Cf. Case of Ximenes Lopes v. Brazil. Judgment of July 4, 2006. Series C No. 149, para. 125, and Case of Cuscul Pivaral et al. v. Guatemala, supra, para. 156. 395 Cf. Medical appraisal in the case of Manuela. Review of clinical and hospital treatment in the Cacaopera Health Unit and the San Francisco National Hospital” (evidence file, folio 191). 396 397 Cf. Expert opinion provided by Guillermo Antonio Ortiz Avendaño during the public hearing held in this case. 69