Prediction of Postoperative Delirium after Gastrointestinal Surgery Using the Mie Constructional Apraxia Scale

Background

Postoperative delirium (POD) is a transient postoperative complication that occurs after surgical procedures. Risk factors reported for POD include dementia and cognitive decline. The purpose of this study was to identify predictors of POD by examining the use of preoperative neuropsychological tests, including the Mie Constructional Apraxia Scale (MCAS), and patient background factors.

Method

The study was performed as a retrospective cohort study. The subjects were 33 patients (mean age, 75.8 ± 10.9 years; male:female ratio, 26:7) who underwent gastrointestinal surgery at Matsusaka City Hospital between December 2019 and April 2021. Data were collected retrospectively from medical records. The study was started after receiving approval from the institution's ethics committee. The survey items included general patient information, nutritional assessment, surgical information, and neuropsychological tests. Subjects were classified into 2 groups according to the presence or absence of POD. If a significant difference was observed between the 2 groups, the sensitivity, specificity, and area under the curve were calculated using a receiver operating characteristic (ROC) curve.

Result

There were 10 patients in the POD group (male:female ratio, 6:4) and 23 patients in the non-POD group (20:3). The POD group had a shorter education history (p = 0.047) and significantly higher MCAS scores (p = 0.007) than the non-POD group. The ROC curve showed a sensitivity of 90%, a specificity of 69%, and an area under the curve of 0.798 when the MCAS cutoff value was set at 3 points.

Conclusion

Preoperative MCAS results were capable of predicting the occurrence of POD after gastrointestinal surgery. In addition, a relatively short education background was also considered a risk factor for POD.

A Prediction Equation to Assess Resting Energy Expenditure in Japanese Patients with COPD

Background: Medical nutrition therapy is important in the management of chronic obstructive pulmonary disease (COPD) patients. Determination of resting energy expenditure is essential to define therapeutic goals for medical nutrition. Previous studies proposed the use of equations to predict resting energy expenditure. No prediction equation is currently available for the Japanese population. The objective of this study was to develop an equation to predict resting energy expenditure in Japanese chronic obstructive pulmonary disease patients. To this end, we investigated clinical variables that correlate with the resting energy expenditure. Methods: This study included 102 COPD patients admitted at the Matsusaka Municipal Hospital Respiratory Center. We measured resting energy expenditure by indirect calorimetry and explored the relationship of resting energy expenditure with clinical variables by univariate and stepwise linear regression analysis. Results: The resting energy expenditure by indirect calorimetry was significantly correlated with fat-free mass, body weight, body mass index, height, gender, and pulmonary function test by univariate analysis. In the stepwise linear regression analysis, the fat-free mass, body weight, and age remained significantly correlated with indirect calorimetry’s resting energy expenditure. The fat-free mass, body weight, and age explained 50.5% of the resting energy expenditure variation. Conclusion: Fat-free mass, body weight, and age were significantly correlated with resting energy expenditure by stepwise linear regression analysis, and they were used to define a predictive equation for Japanese COPD patients.

Modulation of GABA receptors expressed in Xenopus oocytes by 13-L-hydroxylinoleic acid and food additives

To study the effects of 13-L-hydroxylinoleic acid (LOH) and food additives on gamma-aminobutyric acid (GABA) receptors, ionotropic GABA receptors were expressed in Xenopus oocytes by injecting mRNAs prepared from rat whole brain. LOH, which was prepared by reduction of 13-L-hydroperoxylinoleic acid (LOOH), inhibited the response of GABA receptors in the presence of high concentrations of GABA. LOH also inhibited nicotinic acetylcholine, glycine, and kainate receptors, while it had little effect on NMDA receptors expressed in Xenopus oocytes. However, LOH potentiated the response of GABA receptors as well as LOOH in the presence of low concentrations of GABA, possibly increasing the affinity of GABA for the receptors, while linoleic acid did not. Since some modification of the compounds seemed to change their effects on GABA receptors, the responses of GABA receptors elicited by 10 microM GABA were measured in the presence of compounds with various kinds of functional groups or the structural isomers of pentanol. Potentiation of GABA receptors depended strongly on the species of functional groups and also depended on the structure of the isomers. Then effects of various kinds of food additives on GABA receptors were also examined; perfumes such as alcohols or esters potentiated the responses strongly, while hexylamine, nicotinamide, or caffeine inhibited the responses, mainly in a competitive manner, and vanillin inhibited the responses noncompetitively. These results suggest the possibility that production of LOOH and LOH, or intake of much of some food additives, modulates the neural transmission in the brain, especially through ionotropic GABA receptors and changes the frame of the human mind, as alcohol or tobacco does.