Weaknesses and limitations of our study
cognitive impairment, POCD, dementia, psychiatric, cognitive disorders
One of the weaknesses of our study is that we only investigated short‐term postoperative results. Nevertheless, POCD tends to diminish over time (Wang et al., We did not include patients with diagnosed neurological, psychiatric or cognitive conditions, including dementia, in our study. However, we relied on medical records revealing such diagnosis. Since we did not perform any specific tests to screen for preexisting cognitive impairment, it is possible that some of the study participants had previously undiagnosed cognitive disorders.Even though initially an equal number of participants was selected in both study arms, the final outcomes included a different number of patients (48 from the sevoflurane and 34 from the desflurane arm) as a consequence of a higher dropout ratio in the desflurane group. Higher than initially expected dropout ratio also has an impact on the statistical power of the study, since the precalculated sample size was not reached in the final analysis due to unexpected circumstances. The start of COVID‐19 pandemic and subsequent cessation of elective surgery limited our ability to enroll additional patients. Similarly, existent data on the incidence of POCD and cognitive scoring results cover high‐risk procedures, while in our case rather low differences between cognitive scoring results could be expected. Yet, performing profound cognitive testing is complicated, time and human resource‐consuming process. Therefore, it is virtually unfeasible to test extensively large numbers of patients that would be required to detect small and rare changes in cognition.Growing evidence of genetic predisposition for cognitive impairment should be considered in similar trials. Most of our study participants were female. A menopausal loss of female sex hormones may have an impact on the cognitive function deterioration in APOE ε4 genotype female carriers, especially when inhalational anesthesia is used and memory tasks are performed (Cai et al., 