Kathleen M. Patterson

Ketamine Attenuates Delirium After Cardiac Surgery With Cardiopulmonary Bypass

OBJECTIVE To determine if ketamine attenuates postoperative delirium concomitant with an anti-inflammatory effect in patients undergoing cardiac surgery using cardiopulmonary bypass. DESIGN A prospective randomized study. SETTING A Veterans Affairs medical center. PARTICIPANTS Cardiac surgical patients. INTERVENTIONS Patients at least 55 years of age randomly received placebo (0.9% saline, n = 29) or an intravenous bolus of ketamine (0.5 mg/kg intravenously, n = 29) during anesthetic induction in the presence of fentanyl and etomidate. MEASUREMENTS AND MAIN RESULTS Delirium was assessed by using the Intensive Care Delirium Screening Checklist before and after surgery. Serum C-reactive protein concentrations were determined before and 1 day after surgery. The incidence of postoperative delirium was lower (p = 0.01, Fisher exact test) in patients receiving ketamine (3%) compared with placebo (31%). Postoperative C-reactive protein concentration was also lower (p < 0.05) in the ketamine-treated patients compared with the placebo-treated patients. The odds of developing postoperative delirium were greater for patients receiving placebo compared with ketamine treatment (odds ratio = 12.6; 95% confidence interval, 1.5-107.5; logistic regression). CONCLUSIONS After cardiac surgery using cardiopulmonary bypass, ketamine attenuates postoperative delirium concomitant with an anti-inflammatory effect.

Ketamine attenuates post-operative cognitive dysfunction after cardiac surgery

Background: Post‐operative cognitive dysfunction (POCD) commonly occurs after cardiac surgery. Ketamine exerts neuroprotective effects after cerebral ischemia by anti‐excitotoxic and anti‐inflammatory mechanisms. We hypothesized that ketamine attenuates POCD in patients undergoing cardiac surgery concomitant with an anti‐inflammatory effect.

Postoperative cognitive dysfunction in older patients with a history of alcohol abuse.

Background: Postoperative cognitive dysfunction (POCD) affects a significant number of patients and may have serious consequences for quality of life. Although POCD is most frequent after cardiac surgery, the prevalence of POCD after noncardiac surgery in older patients is also significant. The risk factors for POCD after noncardiac surgery include advanced age and preexisting cognitive impairment. Self-reported alcohol abuse is a risk factor for postoperative delirium, but its significance for long-term POCD has not been investigated. The goal of this study was to determine whether neurocognitive function is impaired after noncardiac surgery during general anesthesia in older patients with a history of alcohol abuse. Methods: Subjects aged 55 yr and older with self-reported alcohol abuse (n = 28) and age-, sex-, education-matched nonalcoholic controls (n = 28) were tested using a neurocognitive battery before and 2 weeks after elective surgery (n = 28) or a corresponding time interval without surgery (n = 28). Verbal memory, visuospatial memory, and executive functions were assessed. A neurologic examination was performed to exclude subjects with potential cerebrovascular damage. Results: Significant three-way interactions (analysis of variance) for Visual Immediate Recall, Visual Delayed Recall, Semantic Fluency, Phonemic Fluency, and the Color-Word Stroop Test implied that cognitive performance in the alcoholic group decreased after surgery more than it did in the other three groups. Conclusions: The results suggest that a history of alcohol abuse in older patients presents a risk for postoperative cognitive impairment in the domains of visuospatial abilities and executive functions that may have important implications for quality of life and health risks.

Postoperative Delirium and Short-term Cognitive Dysfunction Occur More Frequently in Patients Undergoing Valve Surgery With or Without Coronary Artery Bypass Graft Surgery Compared With Coronary Artery Bypass Graft Surgery Alone: Results of a Pilot Study

OBJECTIVE The authors tested the hypothesis that patients undergoing valve repair or replacement surgery with or without coronary artery bypass graft (CABG) surgery using cardiopulmonary bypass (CPB) had a greater incidence of postoperative delirium and cognitive dysfunction compared with patients undergoing CABG surgery alone. DESIGN Prospective study. SETTING Veterans Affairs medical center. PARTICIPANTS Forty-four age- and education-balanced male patients (≥ 55 years of age) undergoing elective cardiac surgery with CPB (n = 22 valve ± CABG surgery and n = 22 CABG surgery alone) and nonsurgical controls (n = 22) were recruited. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Delirium was assessed with the Intensive Care Delirium Screening Checklist before and for 5 consecutive days after surgery. Recent verbal and nonverbal memory and executive functions were assessed using a psychometric test battery before and 1 week after cardiac surgery or at 1-week intervals in nonsurgical controls. Intensive care unit stay, hospital stay, and 30-day readmission were significantly (p = 0.03, p = 0.01, and p = 0.04, respectively) longer in patients undergoing valve surgery ± CABG surgery versus CABG surgery alone. Postoperative delirium occurred more frequently (p = 0.01) in patients undergoing valve ± CABG surgery versus CABG surgery alone. Overall cognitive performance (composite z score) after surgery also was impaired significantly (p = 0.004) in patients undergoing valve ± CABG surgery compared with CABG surgery alone. The composite z score after surgery decreased by at least 1.5 standard deviations in 11 patients (50%) versus 1 patient (5%) without valve surgery compared with nonsurgical controls (p = 0.001, Fishers exact test). The presence of delirium predicted a composite z score decrease of 1.2 points (odds ratio = 0.30; 95% confidence interval, 0.13-0.68). CONCLUSIONS The results indicated that patients undergoing valve surgery with or without CABG surgery have a higher incidence of postoperative delirium and cognitive dysfunction 1 week after surgery compared with those undergoing CABG surgery alone.

Postoperative cognitive dysfunction after noncardiac surgery: effects of metabolic syndrome

Purpose Vascular risk factors, including metabolic syndrome, are known to contribute to the development of cognitive dysfunction. We tested the hypothesis that patients with metabolic syndrome are more likely to develop cognitive dysfunction after noncardiac surgery.

Metabolic Syndrome Exacerbates Short-term Postoperative Cognitive Dysfunction in Patients Undergoing Cardiac Surgery: Results of a Pilot Study

OBJECTIVE The authors tested the hypothesis that patients with metabolic syndrome are more likely to develop short-term cognitive dysfunction after cardiac surgery with cardiopulmonary bypass. DESIGN A prospective study. SETTING Veterans Affairs medical center. PARTICIPANTS Fifty-six age- and education-balanced patients undergoing elective cardiac surgery with cardiopulmonary bypass (28 patients with and without metabolic syndrome in two separate groups) and 28 nonsurgical controls were enrolled. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Recent verbal and nonverbal memory and executive functions were assessed using a psychometric test battery before and 1 week after cardiac surgery or at 1-week intervals in nonsurgical controls. Neurocognitive scores under the baseline condition were at least 1 z score (1 standard deviation) worse in surgical patients with compared without metabolic syndrome in all 3 cognitive areas (nonverbal and verbal recent memory and executive functions). Neurocognitive performance further deteriorated after surgery by at least 1 z score on 3 tests in the verbal memory modality (Immediate and Delayed Story Recall and Delayed Word List Recall). Overall cognitive performance (composite z score) after surgery was significantly (p = 0.03) worse in metabolic syndrome patients compared with those who did not have the disorder. CONCLUSIONS The results indicate that short-term cognitive functions were more profoundly impaired in patients with metabolic syndrome undergoing cardiac surgery with cardiopulmonary bypass compared with their healthier counterparts.

Postoperative Delirium is Associated with Postoperative Cognitive Dysfunction at One Week after Cardiac Surgery with Cardiopulmonary Bypass

Postoperative delirium with cognitive impairment frequently occurs after cardiac surgery. It was hypothesized that delirium is associated with residual postoperative cognitive dysfunction in patients after surgery using cardiopulmonary bypass. Male cardiac surgical patients (M age = 66 yr., SD = 8; M education = 13 yr., SD = 2) and nonsurgical controls (M age = 62, SD = 7; M education = 12, SD = 2) 55 years of age or older were balanced on age and education. Delirium was assessed by the Intensive Care Delirium Screening Checklist preoperatively and for up to 5 days postoperatively. Recent verbal and nonverbal memory and executive functions were assessed (as scores on particular tests) before and 1 wk. after surgery. In 56 patients studied (n = 28 Surgery; n=28 Nonsurgery), nine patients from the Surgery group developed delirium. In the Surgery group, the proportion of patients having postoperative cognitive dysfunction was significantly greater in those who experienced delirium (89%) compared with those who did not (37%). The odds of developing this dysfunction in patients with delirium were 14 times greater than those who did not. Postoperative delirium is associated with scores for residual postoperative cognitive dysfunction 1 wk. after cardiac surgery.

Remote Ischemic Preconditioning Prevents Deterioration of Short-Term Postoperative Cognitive Function After Cardiac Surgery Using Cardiopulmonary Bypass: Results of a Pilot Investigation

OBJECTIVE Remote ischemic preconditioning (RIPC) exerts neuroprotective effects in models of cerebral ischemia-reperfusion injury. The authors tested the hypothesis that RIPC decreases the incidence of postoperative delirium and prevents deterioration of short-term postoperative cognitive function in isoflurane-fentanyl-anesthetized patients undergoing cardiac surgery using cardiopulmonary bypass (CPB). DESIGN Randomized, blinded, single-center pilot investigation. SETTING Veterans Affairs Medical Center. PARTICIPANTS Thirty age- and education-matched men≥55 years of age undergoing elective coronary artery or valve surgery using CPB. Fifteen nonsurgical patients also were enrolled. INTERVENTIONS RIPC was produced after induction of anesthesia using 4 cycles of brief (5 minutes) upper extremity ischemia (tourniquet inflation to 200 mmHg) interspersed with 5-minute periods of reperfusion (tourniquet deflation). MEASUREMENTS AND MAIN RESULTS The Intensive Care Delirium Screening Checklist was used to assess delirium before and each day after surgery for as many as 5 consecutive days. Recent verbal and nonverbal memory and executive functions were assessed before and 1 week after surgery using a standard neuropsychometric test battery or at 1-week intervals in nonsurgical controls. The Geriatric Depression and the Hachinski Ischemia scales were used to identify the presence of clinical depression and vascular dementia, respectively. No differences in delirium scores were observed between RIPC and control groups (p=0.54). Baseline neurocognitive scores were similar in patients with versus without RIPC in all 3 cognitive domains. Significant declines in performance on 2 nonverbal memory tests (figure reconstruction and delayed figure reproduction; p=0.001 and p=0.003, respectively) and 1 verbal memory test (delayed story recall; p=0.0004) were observed 1 week after surgery in patients who were not treated with RIPC. There were no changes in performance of measures of executive function in this group. In contrast, performance on all cognitive tests was unchanged after compared with before surgery in patients receiving RIPC. At least a 1-standard deviation decline from baseline in cognitive performance was detected in figure reconstruction, delayed figure reproduction, immediate story recall, and delayed story recall in patients who were not exposed to RIPC. The incidence of at least a 1-standard deviation decline in neuropsychometric tests was observed in significantly fewer (1 v 9; p<0.0001) patients with versus without RIPC treatment based on composite Z-scores. Overall cognitive performance after surgery was better in patients treated with versus without RIPC (p=0.002). Clinical depression and vascular dementia were not detected in either group. CONCLUSION The results of this pilot investigation indicated that RIPC prevented deterioration of short-term postoperative cognitive function but were unable to detect any difference in delirium in isoflurane-fentanyl-anesthetized patients undergoing cardiac surgery using CPB.

History of Post-traumatic Stress Disorder Is Associated With Impaired Neuropsychometric Performance After Coronary Artery Surgery

OBJECTIVE To determine if preoperative history of post-traumatic stress disorder (PTSD) is associated with postoperative cognitive impairment. DESIGN An observational study. SETTING Veterans Affairs Medical Center. PARTICIPANTS Cardiac surgical patients. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Age- and education-balanced patients (≥55 years of age) undergoing cardiac surgery (n = 30 with a history of PTSD+, n = 56 without a history of PTSD-) and nonsurgical controls (n = 28) were recruited. Recent verbal and nonverbal memory and executive functions were assessed before and 1 week after cardiac surgery or at 1-week intervals in nonsurgical controls. Demographic and medical parameters were similar between groups with the exception of preoperative depression and a history of alcohol dependence. Preoperative depression scores were significantly (p = 0.02) higher in PTSD+ compared with PTSD- groups. Immediate Word List Recall and Delayed Word List Recall under baseline conditions were worse in PTSD+ compared with PTSD- patients. Cognitive performance after surgery decreased by at least 1 standard deviation in 27 PTSD- patients (48%) and in 25 PTSD+ patients (83%) (p = 0.002) versus nonsurgical controls. Multivariate regression analysis (including a history of depression and alcohol dependence) revealed that a history of PTSD was significantly associated with overall (including nonverbal recent memory, verbal recent memory, and executive functions) postoperative cognitive dysfunction (p = 0.005). CONCLUSIONS The current findings suggest that patients with a history of PTSD undergoing coronary artery surgery using cardiopulmonary bypass may be especially vulnerable to postoperative cognitive impairment.

Preoperative Dispositional Optimism Correlates With a Reduced Incidence of Postoperative Delirium and Recovery of Postoperative Cognitive Function in Cardiac Surgical Patients

OBJECTIVE To determine if preoperative psychosocial factors including dispositional optimism, perceived social support, and perceived stress correlate with the recovery of postoperative cognition. DESIGN Observational study. SETTING Veterans Affairs medical center. PARTICIPANTS Cardiac surgical patients. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Age- and education-balanced patients (> or =55 years of age) undergoing cardiac surgery (n = 40) and nonsurgical controls (n = 40) were recruited. A psychosocial evaluation for dispositional optimism, perceived social support, perceived stress, and depression was performed before surgery using standardized questionnaires. Delirium was assessed with the Intensive Care Delirium Screening Checklist before and for 5 consecutive days after surgery. Recent verbal and nonverbal memory and executive functions were assessed before and 1 week after cardiac surgery or at 1-week intervals in nonsurgical controls. Preoperative perceived stress significantly (p < 0.01) correlated with preoperative depression scores. Preoperative dispositional optimism significantly (p < 0.05) correlated with preoperative perceived social support. A multiple logistic regression revealed that dispositional optimism significantly (p < 0.02) predicted the absence of postoperative delirium within 5 days of surgery. Patients who showed high levels of dispositional optimism suffered a significantly (p < 0.03) lower incidence of postoperative delirium. Preoperative dispositional optimism also significantly (p < 0.001) correlated with a postoperative cognitive performance determined by composite z scores. A stepwise multiple regression analysis revealed that dispositional optimism significantly (p < 0.05, R(2) = 35%) predicted postoperative cognitive function. CONCLUSIONS Preoperative dispositional optimism, but not perceived social support, perceived stress, and depression positively correlated with a reduced incidence of postoperative delirium within 5 days and recovery of cognitive performance 1 week after cardiac surgery.