Are we using our brains? Diagnosis of postoperative cognitive dysfunction

Neurological dysfunction after cardiac surgery and cardiac intensive care admission: A narrative review part 1: The problem; nomenclature; delirium and postoperative neurocognitive disorder; and the role of cardiac surgery and anesthesia

The association with cardiac surgery with cognitive decline was first reported in the 1960s after the introduction of coronary artery surgery. The incidence in cognitive decline was thought to be more after cardiac surgery, especially with the use of the cardiopulmonary bypass. Anesthesia and surgery are both associated with cognitive decline but many other factors appear to contribute its genesis. On-pump surgery, microembolization during manipulation of the heart and great vessels, temperature changes, pH changes, and altered cerebral perfusion, during cardiac surgery, have all been blamed for this. Postoperative cognitive decline is associated with poor clinical outcomes and higher mortality. Several studies have been conducted in the last decade to determine the genesis of this malady. Current evidence is absolving cardiac surgery and anesthesia to be the primary causes per se of cognitive dysfunction.

Preoperative cognitive intervention reduces cognitive dysfunction in elderly patients after gastrointestinal surgery: a randomized controlled trial

BACKGROUND

Preoperative conditions may play a significant role in postoperative cognitive dysfunction (POCD) development in elderly patients. We aimed to investigate whether preoperative cognitive training could lower the incidence of POCD one week after surgery.

MATERIAL AND METHODS

A total of 141 ASA I-III elderly patients who underwent gastrointestinal surgery were enrolled into the study. Patients were randomized into either the Intervention group (69 analyzed) or the Control group (72 analyzed). Patients in the intervention group were instructed and trained in a cognition mnemonic skill for a total of three 1-hour sessions with the method of loci (MoL). Controls did not receive any cognitive training during hospitalization. All patients were tested using neuropsychological battery tests (NPTs) on admission and one week after surgery.

RESULTS

The incidence of POCD in the intervention group (15.9%) was significantly lower than in the controls (36.1%) (P<0.05). Patients' performance in Brief Visuospatial Memory Test-Revised and Symbol-Digit Modalities Test were improved by the cognitive training. Increasing age, longer length of anesthesia and surgery, and lack of cognitive training were associated with a significantly higher risk of POCD (P<0.05).

CONCLUSIONS

Cognitive training with MoL can reduce the decline of early postoperative cognitive function in elderly patients undergoing major gastrointestinal surgery.

Postoperative cognitive dysfunction in older adults: a call for nursing involvement

As the population continues to age and new medical developments make surgery at advanced ages increasingly possible, it is important to consider how older adults tolerate surgery and anesthesia. Considerable evidence shows that older adults have a higher risk of developing postoperative cognitive dysfunction (POCD), which leads to transient and sometimes long-term cognitive changes that may affect quality of life. Because little is known about how to prevent or treat POCD, it is important that nurses identify ways in which they can intervene to help patients who experience this disorder.

Hippocampal volume reduction in elderly patients at risk for postoperative cognitive dysfunction

PURPOSE

Postoperative cognitive dysfunction (POCD) is a formidable public health issue, which would not only affect the quality of life among elderly patients but also lead to pulmonary infection and increased mortality. While, there is a lack of an effective indicator in predicting POCD. As one pivotal part of the limbic system in brain, hippocampus is associated with cognitive function. Hippocampal atrophy could indicate the degree of changes in cognitive function.

METHODS

Forty-one ASA II or III patients (23 male, 18 female) aged ≥65 years undergoing open gastrointestinal tract surgery were enrolled in this study. MRI was performed to measure the volume of hippocampal formation before surgery and the results were standardized according to individual intracranial volume. All patients underwent a battery of neuropsychological tests including sensitive tests on the Wechsler adult memory scale and Wechsler adult intelligence scale, trail making test and the grooved pegboard test. We used the Z score to identify POCD as recommended by ISPOCD. All patients were then divided into POCD group and non-POCD group according to the results of the neuropsychological tests. The results of the tests were correlated with the volume of hippocampal formation measured by MRI. The value of MRI measurement of hippocampal volume in predicting POCD was analyzed. Multivariate linear correlation analyses of compositive Z score using potential contributing factors such as age, duration of anesthesia, education and hippocampal volume was carried out.

RESULTS

Thirty-six patients completed the whole battery of neuropsychological tests after surgery. Thirteen of the 36 patients were found to have POCD (36 %) on the postoperative 4th day. The hippocampal volume was significantly smaller in POCD group (4.75 ± 0.23) than in non-POCD group (5.06 ± 0.31). Hippocampal volume had great influence on Z score, and had negative correlation with Z score.

CONCLUSION

The MRI measurement of hippocampal volume is suggested to be valuable as a predictor of POCD in the elderly.