Postoperative delirium

Preventing Wernicke Encephalopathy After Bariatric Surgery

Half a million bariatric procedures are performed annually worldwide. Our aim was to review the signs and symptoms of Wernicke's encephalopathy (WE) after bariatric surgery. We included 118 WE cases. Descriptions involved gastric bypass (52%), but also newer procedures like the gastric sleeve. Bariatric WE patients were younger (median = 33 years) than those in a recent meta-analysis of medical procedures (mean = 39.5 years), and often presented with vomiting (87.3%), ataxia (84.7%), altered mental status (76.3%), and eye movement disorder (73.7%). Younger age seemed to protect against mental alterations and higher BMI against eye movement disorders. The WE treatment was often insufficient, specifically ignoring low parenteral thiamine levels (77.2%). In case of suspicion, thiamine levels should be tested and treated adequately with parenteral thiamine supplementation.

Efficacy of Ondansetron in the Prevention or Treatment of Post-operative Delirium-a Systematic Review

Background

Post-operative delirium (POD) is associated with higher rates of functional decline and death. Ondansetron is a serotonin antagonist which could represent a therapeutic or preventive option in POD.

Methods

A systematic review of MEDLINE, EMBASE, CENTRAL, and PsychINFO was performed. Three randomized controlled trials (RCTs) met inclusion criteria (intervention of ondansetron compared to a control group).

Results

Two RCTs examined ondansetron for the treatment of POD in patients after cardiac or post-trauma surgery in the ICU. Studies assessed either a one-time dose or doses for 3 days of ondansetron or haloperidol IV. They suggested similar reductions in average delirium scores and rates in both interventions, although one study suggested ondansetron to be associated with higher rates of rescue haloperidol use. One RCT examined prophylactic ondansetron versus placebo IV, for five days postoperatively, to prevent POD in orthopedic patients. There were significantly fewer delirious patients in the ondansetron group. In general, studies had major methodological limitations and were very heterogenous in study tools, interventions used, and populations studied.

Conclusions

Ondansetron may be an effective agent for the prevention or treatment of POD, but studies are few and of poor quality, thus making the conclusions tenuous. Further large RCTs are needed.

Postoperative delirium in elderly patients with critical limb ischemia undergoing major leg amputation: a retrospective study

BACKGROUND

Critical limb ischemia has been identified as a risk factor for the incidence of postoperative delirium in elderly patients. Limb amputation is the last option in critical limb ischemia treatments. We investigated the incidence and predisposing factors of postoperative delirium in patients undergoing major leg amputation.

METHODS

From January 2012 to December 2016, 121 patients aged over 60 years who had undergone major leg amputation were enrolled in this study. Various factors related to the patients' outcomes were assessed, including demographic, preoperative laboratory, anesthetic, surgical, and postoperative indicators.

RESULTS

Twenty two patients were excluded and 99 patients were assigned to either the delirium group or no delirium group. Forty of them (40%) developed a delirium during 30 days postoperatively. Univariate analysis implied that end-stage renal disease on hemodialysis, alcohol consumption, C-reactive protein, staying in an intensive care unit (ICU), duration of an ICU stay, occurrence of complications, and mortality during six months, were the factors that accounted for significant differences between the two groups. In multivariate analysis, three factors were significantly related to the development of delirium: mortality during six months (odds ratio [OR] = 13.86, 95% CI [2.10-31.90]), alcohol (OR = 8.18, 95% CI [1.13-16.60]), and hemodialysis (OR = 4.34, 95% CI [2.06-93.08]).

CONCLUSIONS

Approximately 40% of the elderly patients suffered from postoperative delirium in major leg amputation. Identifying those with risk factors for postoperative delirium and intervening at the early stage will be of great benefit in major leg amputations for the elderly population.

Cognitive changes after surgery in the elderly: does minimally invasive surgery influence the incidence of postoperative cognitive changes compared to open colon surgery?

BACKGROUND

Postoperative delirium in the elderly is a growing concern. Data regarding significant differences in postoperative cognitive dysfunction (POCD) in elderly persons undergoing laparoscopic versus open colon resection are not well established.

OBJECTIVES

The goal of this study was to compare the incidence of POCD in laparoscopic versus open colon surgery in an elderly population.

DESIGN AND SETTING

A prospective nonrandomized pilot study was conducted at an urban tertiary care hospital.

PARTICIPANTS

The study included patients aged 65 years and above, without documented dementia who underwent elective colon surgery.

MEASUREMENTS

We collected demographic and clinical data, including age, sex, polypharmacy, and comorbidities. The subjects underwent pre- and postoperative Cambridge Neuropsychological Test Automated Battery (CANTAB) testing. Worsening individual scores from the Paired Associated Learning (PAL) and Spatial Working Memory (SWM) portions of CANTAB determined the presence of POCD. Inflammatory cytokine (i.e., IL-6) levels were measured pre- and postoperatively.

RESULTS

We enrolled 44 subjects (26 laparoscopic and 18 open surgery). The two groups did not differ significantly in age, sex, polypharmacy, and comorbidities. The average incidence of POCD was 47%. PAL scores worsened in 12/23 (52%) in the laparoscopic group and in 7/15 (47%) in the open group. These group differences lacked statistical significance (p = 0.75). SWM scores worsened in 14/25 (56%) in the laparoscopic group and in 6/18 (33%) in the open group, which was also not statistically significant (p = 0.12). No age difference occurred between the 'worsened scores' group and 'stable scores' group, and older age was not associated with POCD. IL-6 levels were higher in the open versus the laparoscopic group (p < 0.0001).

CONCLUSION

In this pilot study, the average incidence of POCD was not statistically different between elderly subjects undergoing open versus laparoscopic surgery. Age did not influence the occurrence of POCD. Although inflammatory markers were significantly higher in the open group, consistent with a higher degree of stress response, this group did not have higher rates of delirium. This association is worth to be investigated in a larger sample.

Impact of surgical approach on postoperative delirium in elderly patients undergoing gastrectomy: laparoscopic versus open approaches

BACKGROUND

Postoperative delirium is a frequent complication in elderly patients undergoing major abdominal surgery and is associated with a poor outcome. We compared postoperative delirium in elderly patients following laparoscopic gastrectomy (LG) versus open gastrectomy (OG).

METHODS

In total, 130 patients aged ≥ 65 years with gastric cancer undergoing LG and OG were enrolled prospectively. Postoperative delirium and cognitive status were assessed daily using the Confusion Assessment Method (CAM) and Mini-Mental Status Examination (MMSE), respectively, for 3 days postoperatively. For CAM-positive patients, delirium severity was then assessed using the Delirium Index (DI).

RESULTS

In total, 123 subjects (LG, n = 60; OG, n = 63) were included in the analysis. In both groups, the overall incidences of postoperative delirium were similar: 31.6% (19/60) in the LG group and 41.2% (26/63) in the OG group. When considering only those with delirium, the severity, expressed as the highest DI score, was similar between the groups. A decline in cognitive function (reduction in MMSE ≥ 2 points from baseline) during 3 days postoperatively was observed in 23 patients in the LG group (38.3%) and 27 patients in the OG group (42.9%) (P = 0.744). In both groups, postoperative cognitive decline was significantly associated with postoperative delirium (P < 0.001).

CONCLUSIONS

We found that, compared with traditional open gastrectomy, laparoscopic gastrectomy did not reduce either postoperative delirium or cognitive decline in elderly patients with gastric cancer.

Mild cognitive impairment with associated inflammatory and cortisol alterations as independent risk factor for postoperative delirium

AIMS

The present study aimed to determine the impact of mild cognitive impairment (MCI) on the development of postoperative delirium and, secondly, to assess the association between MCI and raised perioperative cortisol, cytokine, cobalamin and homocysteine levels.

METHODS

The study recruited 113 consecutive adult patients scheduled for cardiac surgery with cardiopulmonary bypass. The patients were examined preoperatively with the Montreal Cognitive Assessment and Trail Making Test. A diagnosis of MCI was established based upon the criteria of the National Institute on Aging and Alzheimer's Association. Patients were screened for delirium within the first 5 days postoperatively.

RESULTS

MCI was diagnosed in 24.8% of the patients, whereas the frequency of delirium was 36%. A multivariate analysis demonstrated that individuals with MCI were at a significantly higher risk of postoperative delirium (OR = 6.33, p = 0.002). Preoperative cortisol, postoperative cortisol and IL-2 plasma levels were higher in the MCI group as compared to non-MCI subjects.

CONCLUSION

MCI is associated with a higher risk of postoperative delirium. Perioperative cortisol and inflammatory alterations observed in MCI may provide a physiological explanation for this increased risk.

Elevated postoperative inflammatory biomarkers are associated with short- and medium-term cognitive dysfunction after coronary artery surgery

PURPOSE

We tested the hypothesis that elevated postoperative interleukin-6 (IL-6) and C-reactive protein (CRP) concentrations are associated with short- and medium-term impairment of cognitive functions in patients after coronary artery surgery using cardiopulmonary bypass.

METHODS

Eighty-six age- and education-balanced patients ≥55 years of age undergoing elective coronary artery bypass surgery with cardiopulmonary bypass and 28 nonsurgical controls with coronary artery disease were enrolled. Recent verbal and nonverbal memory and executive functions were assessed before surgery and at 1 week and 3 months after surgery using a cognitive test battery. IL-6 concentrations were measured before surgery and 4 h after cardiopulmonary bypass, and CRP concentrations were measured before surgery and at 24 and 72 h after anesthetic induction. Overall cognitive function between high and low biomarker concentration groups was analyzed by the Wilcoxon rank-sum test.

RESULTS

Recent memory was at least 1 standard deviation (SD) impaired at 1 week and 3 months in the high-CRP compared with low-CRP and in the high-IL-6 compared with low-IL-6 concentration groups. Overall cognitive function was significantly (P = 0.04 and P = 0.01, respectively) different between the high- and low-CRP concentration groups (CRP assayed 24 h after anesthetic induction) at both 1 week and 3 months. Overall cognitive function was also significantly (P = 0.04) different between the high and low-IL-6 concentration groups at 1 week after surgery.

CONCLUSION

The results suggest that elevated postoperative IL-6 and CRP concentrations are associated with the subsequent development of short- and medium-term impairment of cognitive functions after coronary artery surgery.

Clinical utility and use of DSM-IV and ICD-10 Criteria and The Memorial Delirium Assessment Scale in establishing a diagnosis of delirium after cardiac surgery

Authors evaluated the sensitivity and specificity of DSM-IV and ICD-10 criteria and the cutoff value of the Memorial Delirium Assessment Scale (MDAS) in diagnosing postoperative delirium in 260 cardiac surgery patients. Incidence of delirium diagnosed on the basis of DSM-IV and ICD-10 criteria, and with the use of the MDAS was 11.5%, 9.2%, and 6.5%, respectively. The DSM-IV criteria for delirium were found to be more inclusive than those of ICD-10. The cutoff point of 10 of the MDAS was optimal in relation to the presence or absence of delirium after cardiac surgery.

An evaluation strategy for the early detection of postoperative delirium

The aim of the present study was to identify clinical signs detective of the postoperative delirium at the early stage for nursing management. A total of 66 inpatients undergoing cardiac surgery were interviewed using the Delirium Rating Scale (DRS) and NEECHAM Confusion Scale (NCS) preoperatively and on days 1 and 3 postoperatively. The mean onset of delirium occurred on postoperative day 1.3. Development of delirium was detected early by cognitive impairments in the DRS subscales of perceptual disturbance, hallucination, and cognitive status, and the NCS subscales of attention, command, orientation, and verbal skill. These results suggest that assessment of cognitive status on postoperative day is an important strategy in the early detection of postoperative delirium.

Isoflurane preserves spatial working memory in adult mice after moderate hypoxia

Perioperative hypoxia may contribute to postoperative cognitive impairment. It is unknown, however, whether anesthetics exacerbate or protect against hypoxia-related central nervous system impairment. We sought to determine whether hypoxia alone or in combination with isoflurane disrupts working memory in mice. To this extent, we assigned adult mice to one of four treatments for 1 h: oxygen 21%, oxygen 21% + isoflurane 1.2%, oxygen 8%, or oxygen 8% + isoflurane 1.2%. Mice breathed spontaneously throughout the experiment. Body temperature was maintained at 37 degrees C + 0.5 degrees C. Mice were allowed to recover for 24 h to avoid the confounding influence of residual anesthetics on neurobehavioral performance. Working memory was assessed by use of a Y maze modified for mice. For the training trial, entry to one arm was blocked and mice were permitted to run between the two open arms for 15 min and inspect the objects outside. For the test trial, carried out 1 h later, all arms were open. Time spent in each arm was automatically recorded by a camera and associated software. Mice were tested 1, 4, and 7 days after anesthesia. A different arm was used as the novel arm for each test. Performance was analyzed with repeated-measurements analysis of variance, followed by analysis of simple main effects and by post hoc comparison using Newman-Keuls test when appropriate. P values <0.05 were considered significant. Animals subjected to hypoxia (8% oxygen for 1 h) spent significantly less time in the novel arm 1 day after the insult. The impairment, however, was transient. Hypoxic mice performance improved to the level of the control animals on the fourth post-treatment day. Mice subjected to hypoxia plus isoflurane exhibited no impairment and were comparable to the control group at all time points. Hypoxia transiently impairs performance in a spatial memory task. It appears that isoflurane protects against this deleterious effect of hypoxia.

Postoperative delirium in elderly patients after major abdominal surgery

Background

The aim of this study was to investigate the occurrence of postoperative delirium (POD) in elderly patients undergoing major abdominal surgery and to identify factors associated with delirium in this population.

Methods

Data were collected prospectively from 51 patients aged 65 years or more. Delirium was diagnosed by the Confusion Assessment Method and from the medical records. The Mini Mental State Examination (MMSE) was used to identify cognitive impairment.

Results

POD occurred in 26 of 51 patients. Delirium lasted for 1–2 days in 14 patients (short POD group) and 3 days or more in 12 patients (long POD group). The latter patients had significantly greater intraoperative blood loss and intravenous fluid infusion, a higher rate of postoperative complications, a lower MMSE score on postoperative day 4 and a longer hospital stay than patients without POD. Patients in the short POD group were significantly older than those in the long POD group and those who did not develop delirium.

Conclusion

Approximately half of the elderly patients in this study developed POD. Bleeding was found to be an important risk factor for delirium.

Effects of isoflurane on prefrontal acetylcholine release and hypothalamic Fos response in young adult and aged rats

This experiment investigated the influence of age on prefrontal acetylcholine (ACh) release and Fos response in the hypothalamic paraventricular nucleus and the nucleus tractus solitarius (NTS) of rats following isoflurane anesthesia. It is known that isoflurane decreases acetylcholine release in most brain regions. In the present study, we found that the level of prefrontal acetylcholine was significantly lower in 28-month-old rats (14% of baseline) than in 3-month-old rats (38% of baseline) during 2 h of isoflurane anesthesia (P < 0.05). The old rat group showed significantly greater Fos induction in the paraventricular nucleus compared to the young adult rat group (P < 0.05), indicating that the old rats were subjected to stress. No difference in Fos response was noted in the nucleus tractus solitarius. The old rats displayed a significant increase in feeding behavior during the 3-h recovery period (P < 0.05), but there was no difference in overall acetylcholine levels. Taken together, these findings suggest that isoflurane anesthesia influences old rats more profoundly than young adult rats with regard to reductions in acetylcholine release and stress responses. This may have implications for understanding the development of postoperative delirium in aged patients.

Encephalopathy and Stroke After Coronary Artery Bypass Grafting

Both stroke and encephalopathy are associated with significantly longer lengths of stay in the hospital and with significantly higher rates of mortality. Those at risk for either stroke or encephalopathy, or both of these adverse outcomes after surgery, can be identified prior to surgery using information available to physicians. For those at higher risk for these outcomes, we suggest the following: 1) An imaging study of the brain, performed prior to surgery, may indicate the degree of cerebrovascular disease. At present we do not have this information on most patients. 2) The status of arteriosclerotic disease of the aorta should be determined prior to surgery or at the time of surgery. 3) For those with significant aortic and cerebrovascular disease, alternatives to the conventional ways of performing coronary artery bypass grafting (CABG) should be considered. These alternatives include percutaneous transluminal coronary angioplasty, off-pump surgery, and CABG using filters or inputs from the pump that selectively protect the brain.

Predictors of delirium after cardiac surgery delirium: Effect of beating-heart (off-pump) surgery

BACKGROUND

Despite improved outcomes after cardiac operations, postoperative delirium remains a common complication that is associated with increased morbidity and prolonged hospital stay.

METHODS

Univariate and multivariate predictors of postoperative delirium were determined from prospectively gathered data on 16,184 patients undergoing cardiac operations with cardiopulmonary bypass (conventional, n = 14,342) and without cardiopulmonary bypass (beating-heart surgery, n = 1847) between April 1996 and August 2001. Delirium was defined as a transient mental syndrome of acute onset characterized by global impairment of cognitive functions, a reduced level of consciousness, attentional abnormalities, increased or decreased psychomotor activity, and a disordered sleep-wake cycle.

RESULTS

The overall prevalence of postoperative delirium was 8.4%. Of 49 selected patient-related risk factors and treatment variables, 35 were highly associated with postoperative delirium by univariate analysis. Stepwise logistic regression revealed the following variables as independent predictors of delirium: history of cerebrovascular disease, peripheral vascular disease, atrial fibrillation, diabetes mellitus, left ventricular ejection fraction of 30% or less, preoperative cardiogenic shock, urgent operation, intraoperative hemofiltration, operation time of 3 hours or more, and a high perioperative transfusion requirement. Two variables were identified as having a significant protective effect against postoperative delirium: beating-heart surgery and younger patient age.

CONCLUSIONS

Postoperative delirium is a common complication in cardiac operations. The increased use of beating-heart surgery without cardiopulmonary bypass may lead to a lower prevalence of this complication and thus improve patient outcomes.

Intensive care unit syndrome/delirium is associated with anemia, drug therapy and duration of ventilation treatment

BACKGROUND

We have performed a prospective qualitative investigation of the ICU syndrome/delirium; the main parts of which have recently been published. The aim of the present study was to explore the relationship between the ICU syndrome/delirium and age, gender, length of ventilator treatment, length of stay and severity of disease, as well as factors related to arterial oxygenation and the amount of drugs used for sedation/analgesia.

METHODS

Nineteen mechanically ventilated patients who had stayed in the ICU for more than 36 h were closely observed during their stay, and interviewed in depth twice after discharge. Demographic, administrative and medical data were collected as a part of the observation study.

RESULTS

Patients with severe delirium had significantly lower hemoglobin concentrations than those with moderate or no delirium (P=0.033). Patients suffering from severe delirium spent significantly longer time on the ventilator and at the ICU, and were treated with significantly higher daily doses of both fentanyl (P=0.011) and midazolam (P=0.011) in comparison with those reporting only moderate or no symptoms of delirium. There were no significant differences in the Therapeutic Intervention Scoring System scores, reflecting the degree of illness, between patients with and without delirium.

CONCLUSION

The development of the ICU syndrome/delirium seems to be associated with decreased hemoglobin concentrations and extended times on the ventilator. Prolonged ICU stays and treatment with higher doses of sedatives and opioids in patients with delirium appear to be secondary phenomena rather than causes.