The assessment of postoperative cognitive function
Tóm tắt
Postoperative cognitive function (POCD) has been subject to extensive research. In the literature, large differences are apparent in methodology such as the test batteries, the interval between sessions, the endpoints to be analysed, statistical methods, and how neuropsychological deficits are defined. Traditionally, intelligence tests or tests developed for clinical neuropsychology have been used. The tests for detecting POCD should be based on well‐described sensitivity and suitability in relation to surgical patients. In tests using scores, floor/ceiling effects may compromise the evaluation if the tests are either too easy or to difficult. Uncontrolled testing facilities and change of test personnel may affect the test performance. Practice effects are pronounced in neuropsychological tests but have generally been ignored. The use of a suitable normative population is essential to allow correction for practice effects and variability between sessions. Missing follow‐up may severely compromise valid conclusions since subjects unable or unwilling to be examined are particularly prone to suffer from POCD. In the statistical analysis of the test results, the evaluation should be based on differences between pre‐ and postoperative performance. Parametric statistical tests are not relevant unless the appropriate Gaussian distributions are present, perhaps after transformation of data. The definition of cognitive dysfunction should be restrictive and the criteria should be fulfilled in only a small proportion of volunteers. In the literature, these requirements often have not been fulfilled. This precludes a reasonable estimation of the incidence of POCD and the conclusions of comparative studies should be interpreted with great caution. In this review article, we present a number of recommendations for the design and execution of studies within this area. In addition, the critical reader may use these recommendations in the evaluation of the literature.
Từ khóa
Tài liệu tham khảo
Simpson BR, 1961, The effects of anaesthesia and elective surgery on old people., Lancet, 2, 887
Savageau JA, 1982, Neuropsychological dysfunction following elective cardiac operation. I. Early assessment., J Thorac Cardiovasc Surg, 84, 585, 10.1016/S0022-5223(19)38988-3
Savageau JA, 1982, Neuropsychological dysfunction following elective cardiac operation. II. A six‐month reassessment., J Thorac Cardiovasc Surg, 84, 595, 10.1016/S0022-5223(19)38989-5
Shaw PJ, 1986, Early intellectual dysfunction following coronary bypass surgery., Q J Med, 58, 59
Shaw PJ, 1987, Long‐term intellectual dysfunction following coronary artery bypass graft surgery: a six month follow‐up study., Q J Med, 62, 259
Hammeke TA, 1988, Neuropsychologic alterations after cardiac operation., J Thorac Cardiovasc Surg, 96, 326, 10.1016/S0022-5223(19)35280-8
Lezak MD, 1995, Neuropsychological assessment.
Laursen P, 1997, The impact of aging on cognitive functions. An 11 year follow‐up study of four age cohorts., Acta Neurol Scand, 96, 1
Galasko D, 1993, Repeated exposure to the Mini‐Mental State Examination and the Information‐Memory‐Concentration Test results in a practice effect in Alzheimer’s disease., Neurology, 43, 1559, 10.1212/WNL.43.8.1559
Klonoff H, 1989, Two‐year follow‐up study of coronary bypass surgery., J Thorac Cardiovasc Surg, 97, 78, 10.1016/S0022-5223(19)35128-1
Grote CL, 1992, Cognitive outcome after cardiac operations., J Thorac Cardiovasc Surg, 104, 1405, 10.1016/S0022-5223(19)34636-7
Townes BD, 1989, Neurobehavioral outcomes in cardiac operations., J Thorac Cardiovasc Surg, 98, 774, 10.1016/S0022-5223(19)34300-4
O'Brien DJ, 1992, Patient memory before and after cardiac operations., J Thorac Cardiovasc Surg, 104, 1116, 10.1016/S0022-5223(19)34700-2
Roine RO, 1993, Neuropsychological sequelae of cardiac arrest., JAMA, 269, 237, 10.1001/jama.1993.03500020071034
Garvey JW, 1983, The effect of arterial filtration during open heart surgery on cerebral function., Circulation, 68, 125
Åberg T, 1984, Adverse effects on the brain in cardiac operations as assessed by biochemical, psychometric, and radiologic methods., J Thorac Cardiovasc Surg, 87, 99, 10.1016/S0022-5223(19)37448-3
Ellis RJ, 1980, Reduction of flow rate and arterial pressure at moderate hypothermia does not result in cerebral dysfunction., J Thorac Cardiovasc Surg, 79, 173, 10.1016/S0022-5223(19)37971-1
Williams‐Russo P, 1995, Cognitive effects after epidural vs general anesthesia in older adults., JAMA, 274, 44, 10.1001/jama.1995.03530010058035
Heyer EJ, 1996, Neuropsychometric changes in patients having surgery for carotid endarterectomy., Anesthesiology, 85, A1184
Gruvstad M, 1962, Changes in mental functions after induced hypotension., Acta Psych Scand, 37