Postoperative Neurocognitive Disorders: the Legacy of Almost 400 Years of History (Review)

The history of the study of postoperative neurocognitive disorders (PND) looks as a long and thorny path of more than 400 years. Despite all accumulated data on PND risk factors and outcomes, there’s still no complete understanding of the etiology and pathogenesis of this complication. Moreover, current anesthesiologyresuscitation practice still faces challenges and has pending questions in diagnosis and classification of postoperative neurocognitive disorders. The purpose of the review. To contemplate the evolution in the perceptions of the international medical community (IMC) regarding diagnostic approaches and algorithms in PND management. The review covers the history of development of such PND concepts as postoperative delirium, postoperative cognitive dysfunction, emergence agitation and emergence delirium. Also, the pre-existing and current international classifications of postoperative neurocognitive disorders are discussed in chronological order, supplemented by the analysis of their strengths and weaknesses. The paper also delves into current viewpoints concerning the etiology of particular postoperative neurocognitive disorders, and PND potential relevance for postoperative outcomes. Conclusion. Current algorithms and modalities used for PND diagnosis, are novel but yet not ultimate for IMC in the context of continuous progress in medical practice. Early postoperative neurocognitive disorders remain the most poorly studied phenomena with no approved definitions and diagnostic modalities to identify. It is probably the time for IMC to undertake a joint effort to find answers to current unresolved questions regarding postoperative neurocognitive disorders.