Predicting post-surgical cognitive disturbance in older Taiwanese patients

Delirium and depression in cardiac surgery: A comprehensive review of risk factors, pathophysiology, and management

BACKGROUND

Mental health and wellbeing continue to gain more attention as they are inextricably associated with clinical outcomes, particularly quality of life. Many medical ailments and major surgeries affect patients' mental health, including depression and delirium.

AIMS

The objective of this manuscript was to comprehensively review and critically examine the literature pertaining to cardiac surgery, depression, and delirium.

METHODS

This is a narrative review article. We performed our search analysis by using the following key words: "Cardiac Surgery", "Depression", "Delirium", "Clinical outcomes", and "Mental Health". Search analysis was done on MedLine PubMed, accessing indexed peer-reviewed publications.

RESULTS

Cardiac Surgery is a life-altering intervention indicated to improve morbidity and mortality in patients with cardiovascular diseases. Psychiatric conditions before and after cardiac surgery worsen patient prognosis and increase mortality rate. Specifically, preoperative depression increases postoperative depression and is associated with impaired functional status, slow physical recovery, and an increased readmission rate.

DISCUSSION

Although the exact pathophysiology between depression and cardiovascular disease (CVD) is unknown, several pathways have been implicated. Unmanaged depression can also lead to other psychological conditions such as delirium. Like depression, the exact association between delirium and CVD is not well understood, but believed to be multifactorial.

CONCLUSION

Herein, we provide a comprehensive review of the links between depression, delirium, and cardiovascular surgery. We critically examine the current data that pertains to the pathophysiology of these debilitating mental health issues in the context of cardiac surgery. Finally, we summarize the various treatment options available for managing depression and delirium in the cardiac surgery patient population.

Neurocognitive and behavioural performance of healthy volunteers receiving an increasing analgesic-range infusion of ketamine

BACKGROUND

The acute and delayed effect of analgesic-range doses of ketamine on neurocognitive and behavioural outcomes is understudied. Using a non-controlled open-labelled design, three (1-h duration) increasing intravenous (IV) ketamine infusions comprising (i) 30 mg bolus of ketamine + 8 mg/h IV infusion, (ii) 12 mg/h IV infusion and (iii) 20 mg/h infusion were administered to 20 participants (15 male, 5 female, mean age = 30.8 years). Whole-blood ketamine and norketamine concentrations were determined at each treatment step and post-infusion.

METHODS

The Cambridge Neuropsychological Test Automated Battery (CANTAB) was used to assess reaction/movement time (RTI, Simple and 5-Choice), visuospatial working memory (SWM), spatial planning (SOC) and subjective effects (visual analogue scale; VAS) during treatment and at post-treatment.

RESULTS

Significant main effects were reported for time (dose) on CANTAB RTI 5-Choice reaction (F(4,18) = 3.41, p = 0.029) and movement time (F(4,18) = 4.42, p = 0.011), SWM (F(4,18) = 4.19, p = 0.014) and SOC (F(4,18) = 4.13, p = 0.015), but not RTI Simple reaction or movement time. Post hoc analyses revealed dose-dependent effects for both RTI 5-Choice reaction and movement time (all p < 0.05). Post-treatment performance on all neurocognitive and behavioural tasks returned to baseline levels. Regression analyses revealed a weak positive linear association between SWM 'strategy' score (R² = 0.103, p < 0.001), all performance-based CANTAB VAS items (R² range 0.005-0.137, all p < 0.05) and ketamine blood concentrations.

DISCUSSION

The open-label, non-controlled trial design somewhat precludes the ability to adequately account for random treatment effects. Notwithstanding, these results suggest that analgesic doses of ketamine produce acute, selective, dose-dependent deficits in higher-order neurocognitive and behavioural domains.

The virtual gateway: opening doors in delirium teaching and learning

Delirium is a common, serious and potentially preventable problem. It is argued here that knowledge and skills for effective assessment and treatment of delirium cannot be considered 'specialist'. Rather, delirium is a problem that requires a healthcare team approach to assessing patients, identifying risks or symptoms and reducing precipitating factors. Research from the preceding decade suggests that the clinical reality is falling short of this ideal with the result that many cases of delirium go undetected and many precipitating factors are not reduced where this is indeed possible. This presents a challenge for the education of nursing and medical students and for the development of qualified staff in practice. The current paper outlines an educational approach, e-learning, which increases access for learners, integrates knowledge and skill development and promotes active, problem-based learning.

Prevalence and Risk Factors for Postoperative Delirium in a Cardiovascular Intensive Care Unit

Background Delirium after cardiac surgery is a common complication in cardiovascular intensive care units. The prevalence of delirium and its likely risk factors have not previously been explored in a single sample of postoperative cardiac patients in an intensive care unit.

Objective To compare a variety of characteristics in patients with and without delirium and to identify risk factors associated with delirium in patients hospitalized in an intensive care unit after cardiac surgery.

Methods A retrospective chart review was used to collect data on 288 patients who had open heart surgery during the period 2004 to 2005 at Chang Gung Memorial Hospital in northern Taiwan. A researcher-designed checklist of 52 patient-related risk factors for delirium was used to collect preoperative, intra-operative, and postoperative data. All patients were assessed by psychiatrists, and delirium was diagnosed according to criteria of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition. Data were analyzed via univariate analysis and multivariate logistic regression.

Results The prevalence of postoperative delirium was 41.7%. Patients with and without delirium differed significantly on 29 variables. Four postoperative factors, hematocrit less than 30%, cardiogenic shock, hypoalbuminemia, and acute infection, were significant, independent predictors of postoperative delirium.

Conclusions The results of this study can be used to develop a revised checklist of 29 preoperative, intraoperative, and postoperative risk factors for delirium, with special attention to the 4 predictive postoperative factors. Use of such a checklist may facilitate the ability to prevent or detect delirium early and provide suitable treatment.