POD is a common complication for surgical patients over the age of 60 years. However, these studies are heterogeneous in the study design, selected surgical patient population and outcome measurement tools complicating the synthesis of the systemic search to draw conclusions. These seem to suggest a high pretest probability in studying the ability of POD to predict intermediate-term cognitive decline. Out of the 28 relevant articles, 21 (75%) showed significant result in the relationship between postoperative delirium (POD) and intermediate-term to long-term cognitive decline (see online supplementary appendix A). JZC and RT reviewed the 301 search results and found 28 articles that were relevant to our clinical question.
Articles in English or with English translation were considered. Ovid Medline was searched for studies published between 1981 and September 2016 using the query: Postoperative or after surgery AND Delirium AND Cognitive function or dementia AND Elderly AND Long-term or intermediate term or follow up or cohort studies or retrospective studies. Therefore, clarification of cognitive outcomes would assist patients and practitioners in making an informed decision about the relative risks and benefits of proceeding with elective surgery.Ī systemised literature review was conducted with the help of a librarian experienced in a systemic review (see Acknowledgements). Acute and long-term cognitive changes related to surgical intervention are particularly distressing to patients and their families. 2–6 Importantly, the population of Americans older than 60 years is projected to double over the next 30 years, 7 and many will require surgery. While several influential studies demonstrated early POCD lasting up to 3 months, the persistence of this cognitive decline has been controversial. Postoperative cognitive decline (POCD) has been a growing topic for scientific investigation after several studies were published by the International Study of Post-Operative Cognitive Dysfunction group. 1 This pervasive view continues to concern patients and their families, fuelled by anecdotal evidence and media coverage.
Since Bedford’s 1955 case series suggesting an association between surgical intervention and cognitive impairment, there has been growing concern among the public that cognitive decline is a common consequence of surgery.