Table 3.
Important Questions for Future Research, Suggestions and Challenges
| Research Question | Suggested Study Design and Methods* | Issues/Challenges |
|---|---|---|
| -What aspects of aging are most closely tied to POCD risk? | Cohort Design, with cognitive testing and geriatric evaluations | Important to have involvement of geriatricians |
| Are certain patients (ie the elderly, or those with less cognitive reserve) at higher risk for POCD after general vs regional anesthesia? | RCT of general vs regional anesthesia with cognitive testing, stratified by age group and/or other variables | Patient recruitment, importance of minimizing sedation in the regional arm to allow for a true comparison of general vs regional anesthesia |
| -Is POCD associated with an increased long term Risk of dementia? | Prospective Cohort with long term follow up, cognitive and MCI/AD/dementia screening | Need to enroll patients who may already have MCI or other baseline cognitive deficits. Large samples sizes needed to obtain sufficient power for clinically relevant effects; see (167) and (28) for discussion of this issue. |
| -What is the relationship between central neuroinflammation, cerebrovascular white matter disease, AD pathology (and/or perioperative changes in these pathologic processes) and POCD? | Cohort Design, Cognitive Testing, neuroimaging, and CSF AD and inflammatory biomarker studies | Patient Recruitment |
| -Is POCD associated with altered functional brain connectivity? | Cohort Design, cognitive testing and functional MRI scans | Patient Recruitment, MRI safety issues may exclude some elderly patients with pacemakers/AICDs, metal joint replacements, etc. |
| -Are there CSF biomarkers of POCD? | Cohort Design, Cognitive Testing and CSF sampling | Patient Recruitment |
| -Would SSRI treatment prevent POCD, improve cognitive trajectory, affect and mood, and/or improve quality of life in patients with POCD? | RCT, cognitive testing, quality of life measurement, depression/anxiety and affect rating scales | Possible Side Effects from Treatment |
| -Would preconditioning with ischemia or anesthetic agents help prevent POCD? | RCT | Patient recruitment |
| -Would physical and/or cognitive prehabilitation reduce the incidence or severity of POCD, and/or improve quality of life after surgery in the elderly? | RCT | Blinding difficult if not impossible; need to ensure patient participation in prehabilitation interventions. |
| -How long does POCI last? Does it depend on surgery type? To what extent does POCI reflect surgically-induced improvements in underlying disease processes, quality of life, and/or mental health? | Cohort design | Careful statistical analysis required to separate true POCI from test practice effects. |
*
For prospective study designs, it is important that all testing be completed both before and after surgery.