Postoperative delirium in elderly patients after major abdominal surgery

Comparison of three scores to screen for delirium in the recovery room

BACKGROUND

Delirium is often seen in the recovery room and is a predictor for postoperative delirium on the ward. However, monitoring to detect delirium in the recovery room as a basic prerequisite for early intervention is rarely used. The aim of this study was to identify a valid and easy-to-use test for early screening of delirium in the recovery room.

METHODS

One hundred and fifty-four adult patients admitted to the recovery room during regular working hours were included. A screening assessment for delirium was performed in the recovery room by a trained research team at the time when the patient was judged to be 'ready for discharge'. Delirium monitoring was performed with the Confusion Assessment Method (CAM), the Delirium Detection Score (DDS), and the Nursing Delirium Screening Scale (Nu-DESC). The Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV criteria were used as the gold standard.

RESULTS

Delirium in the recovery room was seen in 21 patients (14%) with the DSM-IV criteria, in 11 patients (7%) with the CAM, in four patients (3%) with the DDS, and in 37 patients (24%) with the Nu-DESC. Sensitivity and specificity were 0.43 and 0.98 for the CAM, 0.14 and 0.99 for the DDS, and 0.95 and 0.87 for the Nu-DESC, respectively.

CONCLUSIONS

All scores used were very specific, but the CAM and the DDS were less sensitive compared with the gold standard. Overall, the Nu-DESC was the most sensitive test in the recovery room to detect delirium.

Neuroinflammation and cognitive function in aged mice following minor surgery

Following surgery, elderly patients often suffer from postoperative cognitive dysfunction (POCD) which can persist long after physical recovery. It is known that surgery-induced tissue damage activates the peripheral innate immune system resulting in the release of inflammatory mediators. Compared to adults, aged animals demonstrate increased neuroinflammation and microglial priming that leads to an exaggerated proinflammatory cytokine response following activation of the peripheral immune system. Therefore, we sought to determine if the immune response to surgical trauma results in increased neuroinflammation and cognitive impairment in aged mice. Adult and aged mice underwent minor abdominal surgery and 24h later hippocampal cytokines were measured and working memory was assessed in a reversal learning version of the Morris water maze. While adult mice showed no signs of neuroinflammation following surgery, aged mice had significantly increased levels of IL-1beta mRNA in the hippocampus. Minor surgery did not result in severe cognitive impairment although aged mice that underwent surgery did tend to perseverate in the old target during reversal testing suggesting reduced cognitive flexibility. Overall these results suggest that minor surgery leads to an exaggerated neuroinflammatory response in aged mice but does not result in significantly impaired performance in the Morris water maze.

Pre-operative mild cognitive dysfunction predicts risk for post-operative delirium after elective cardiac surgery

BACKGROUND AND AIMS

To identify pre-operative risk factors for delirium in patients undergoing elective cardiac surgery, using clearly defined diagnostic criteria for delirium, and a thorough clinical assessment.

METHODS

The incidence of post-operative delirium in 107 patients >or=60 years undergoing elective cardiac surgery was calculated. None of the patients included suffered from dementia. Pre-operative cognitive function in all patients was assessed using the Mini Mental State Examination (MMSE) and post-operative delirium was diagnosed using the Confusion Assessment Method (CAM). Post-operative clinical and cognitive assessments were carried out for all patients.

RESULTS

Twenty-five patients (23.4%) developed delirium post-operatively. Clinical parameters, including age, gender, co-morbidities, medications, and peri-operative parameters, were similar in patients with and without post-operative delirium. Patients with pre-operative subjective memory complaints and lower MMSE scores, undergoing valve operation or valve + coronary artery bypass grafting (CABG), exhibited an increased risk of developing post-operative delirium. Additionally, delirious patients had a significant decline in post-operative MMSE score compared with the non-delirious ones.

CONCLUSIONS

The main pre-operative risk factors for post-operative delirium after elective cardiac operations were subjective memory complaints, mild cognitive impairment, and type of cardiac surgery, such as valve procedures. This study suggests that cognitive evaluation should be included in pre-operative assessment.

Surgery in older people: an update

In the past two decades, the rate of surgery in older people has increased more rapidly than the rate of aging of the population, so both a larger proportion and a greater number of older people are now undergoing surgery. This may partly reflect a cultural change in surgery and anaesthesia with respect to a greater willingness to undertake elective procedures in older people, although there remain areas where they have less access to surgery than do younger patients. For instance, older people are less likely to undergo operative procedures after a cancer diagnosis. Furthermore, in those who do have surgery, resection rate (i.e. curative therapy) is lower than in younger people with equivalent tumour stages, and even more so in older patients with COPD, cardiovascular disease or diabetes. This article explores the complex relationship between age and surgical outcome, provides an evidence-based overview of risk assessment and common postoperative problems in older people, and summarizes good practice points (at times necessarily pragmatic) for clinical management of the older surgical patient. There has been a substantial expansion in the literature examining risks, outcomes and interventions in older surgical patients since the previous review article of this subject published in this journal. Although we do not cover anaesthesia in older people, the review of that topic remains relevant. The American Society of Anaesthesiologists' Classification of Risk which illustrates that risk is disease- rather than age- based, is shown in Table 1. Most publications examine elective rather than emergency surgery in older people (with the exception of hip fracture), and this is reflected in the content of the paper.

Uncomplicated general anesthesia in the elderly results in cognitive decline: does cognitive decline predict morbidity and mortality?

Elderly surgical patients constitute a unique surgical group. They require special consideration in order to preempt the long term adverse effects of anesthesia. This paper examines the proposition that general anesthesia causes harm to elderly patients with its impact being felt long after the anesthetic agents are cleared from the body. One complication, Postoperative Cognitive Decline (POCD), is associated with the administration of anesthesia and deep sedation. Its' occurrence may herald an increase in morbidity and mortality. Based on both human and animal data, this paper outlines a unitary theoretical framework to explain these phenomena. If this hypothesis proves to be correct, anesthesiologist should consider regional rather than general anesthesia for equivalent surgical procedures to reduce POCD and consequently achieving superior patient outcome.

Transanal endoscopic micro-surgery (TEMS) for the management of large or sessile rectal adenomas: a review of the technique and indications

In this review article the surgical technique of Transanal Endoscopic Microsurgery (TEMS) is examined. A number of techniques have been used to treat adenomas of the rectum. The treatment of large adenomas which occupy a large surface of the rectal lumen or adenomas which are flat and grow in a "carpet-like" fashion is particularly challenging. Major rectal surgery carries a risk of morbidity and mortality, particularly in elderly and unfit patients. Although local excision with transanal resection (TAR) and the Kraske sacral operation have been used in the past, during the last twenty years TEMS has become the method of choice for those lesions. TEMS is efficient and minimally invasive. The technique allows the patient to recover rapidly and the incidence of complications is much lower than that of major surgery. In case of recurrence the option of repeat TEMS or major surgery remain available. TEMS has been slow to gain popularity mainly for reasons of cost and steep learning curve but it is now an established procedure and a valuable therapeutic option which is particularly useful for elderly and unfit patients. Gastroenterologists should be aware of the nature and indications of TEMS in order to advise and refer selected patients with rectal adenomas accordingly.