[Effects of early intervention training on cognitive impairment in critical patients]

To investigate the characteristics of cognitive impairment in critical patients, and to explore the role of early cognitive intervention training in improving cognitive impairment in critical patients.

A prospective cohort study was conducted. 133 patients in conscious and normal intelligence admitted to intensive care unit (ICU) of Hefei Second People's Hospital from January 2015 to June 2018 were enrolled. The patients were divided into control group (n = 66) and cognitive intervention group (n = 67) according to random number table based on chronological number for entry into the study. Cognitive function was assessed by Montreal cognitive assessment scale (MoCA scale) within 24 hours after ICU admission. The patients in the cognitive intervention group received a series of scientifically designed cognitive training sessions (playing electronic musical keyboard, learning simple Spanish, clock-drawing, psychological intervention) for 2 months, and follow-up was completed if the patient was discharged from ICU. While the patients in the control group did not undertake any cognitive training. After 2 months, the cognitive function of patients in both groups were assessed with MoCA scale. Subgroup analysis was conducted according to different age groups (20-40 years old, 41-60 years old, 61-80 years old) to explore the effect of cognitive intervention training in different age groups. According to the subjective evaluation of the patient's ability to live 2 months after cognitive intervention by the patient or his relatives, receiver operating characteristic (ROC) curve was plotted to evaluate the predictive value of the total score of MoCA for patients' ability to live after cognitive intervention.

133 critical patients were enrolled in the final analysis. There was no significant difference in gender, age, education, complications, ICU hospitalization, sedative or analgesic drug usage between the two groups, indicating that the data of the two groups were balanced and comparable. No significant difference in MoCA scale total score or sub-item cognitive domain score within 24 hours of ICU admission was found between the two groups. After 2 months of intervention, the incidence of cognitive impairment in the cognitive intervention group was significantly lower than that in the control group [38.8% (26/67) vs. 60.6% (40/66), χ² = 6.321, P = 0.015]. The total score of MoCA scale and four sub-item cognitive domain scores including visual space and execution power, protection of memory, attention execution, and orientation in the cognitive intervention group were significant higher than those in the control group (MoCA scale total score: 26.73±1.92 vs. 24.95±2.26, visual space and executive power score: 4.39±0.70 vs. 3.95±0.88, protection of memory score: 8.91±1.03 vs. 8.24±1.37, attention execution score: 5.21±0.77 vs. 4.79±1.00, orientation score: 5.67±0.53 vs. 5.44±0.68, all P < 0.05), but no significant difference was found in verbal skills score (2.55±0.56 vs. 2.53±0.56, P > 0.05). Subgroup analysis showed that the total MoCA scale score of the younger sample (20-40 years old, n = 20) was recovered by 2.10±1.55 in the cognitive intervention group after 2 months of cognitive intervention, which was significantly higher than that in the control group (n = 21; 0.24±2.76, P < 0.05). In the middle-aged and the older population [aged 41-60 years old (n = 20) and 61-80 years old (n = 27)], the total MoCA scale scores were recovered slightly after cognitive intervention as compared with those in the younger sample (0.43±1.47, -1.91±2.20 vs. 2.10±1.55, both P < 0.05), which were significantly lower than those in the control group [aged 41-60 years old (n = 21) and 61-80 years old (n = 24), -0.78±1.38, -4.41±2.17, both P < 0.01]. It was suggested that cognitive intervention training played an active role in the recovery of cognitive function in young critical patients. It was shown by ROC curve analysis that the area under ROC curve (AUC) of MoCA scale total score for predicting daily life ability after cognitive intervention was 0.732 with 95% confidence interval (95%CI) of 0.646-0.819. When the best cut-off value was 24.5, the sensitivity was 89.3%, the specificity was 60.2%, the positive predictive value was 85.7%, and the negative predictive value was 80.8%.

Early cognitive intervention could efficiently abate the deterioration of cognitive function in critical patients in ICU and had significant effects on the visual space and executive power, protection of memory, attention execution and orientation. Cognitive intervention exerted significantly positive effects on the recovery of cognitive function in the younger sample population (aged 20-40 years old).