Incidence and risk factors of PostopeRativE delirium in intensive care unit patients: A study protocol for the PREDICt study

Two-stage prediction model for postoperative delirium in patients in the intensive care unit after cardiac surgery

OBJECTIVES

Postoperative delirium is a common severe complication in patients in the intensive care unit after cardiac surgery. We developed a two-stage prediction model and quantified the risk of developing postoperative delirium to assist in early prevention before and after surgery.

METHODS

We conducted a prospective cohort study and consecutively recruited adult patients after cardiac surgery. The Confusion Assessment Method for patients in the intensive care unit was used to diagnose delirium 5 days postoperatively. The stage I model was constructed using patient demographics, health conditions and laboratory results obtained preoperatively, whereas the stage II model was built on both pre- and postoperative predictors. The model was validated internally using the bootstrap method and externally using data from an external cohort.

RESULTS

The two-stage model was developed with 654 patients and was externally validated with 214 patients undergoing cardiac surgery. The stage I model contained 6 predictors, whereas the stage II model included 10 predictors. The stage I model had an area under the receiver operating characteristic curve of 0.76 (95% confidence interval: 0.68-0.81), and the stage II model's area under the receiver operating characteristic curve increased to 0.85 [95% confidence interval (CI): 0.81-0.89]. The external validation resulted in an area under the curve of 0.76 (95% CI: 0.67-0.86) for the stage I model and 0.78 (95% CI: 0.69-0.86) for the stage II model.

CONCLUSIONS

The two-stage model assisted medical staff in identifying patients at high risk for postoperative delirium before and 24 h after cardiac surgery. This model showed good discriminative power and predictive accuracy and can be easily accessed in clinical settings.

TRIAL REGISTRATION

The study was registered with the US National Institutes of Health ClinicalTrials.gov (NCT03704324; registered 11 October 2018).

Effect of Programmed Comprehensive Nursing for Postoperative Delirium in Intensive Care Unit Patients

Background

This study is to evaluate the effect of programmed comprehensive nursing for postoperative delirium in intensive care unit (ICU) patients.

Methods

A total of 90 cases of ICU surgery patients admitted to our hospital from July 2019 to July 2020 were recruited and assigned via the random number table method (1 : 1) to receive either conventional nursing (control group) or programmed comprehensive nursing (experimental group). The delirium assessment method was used to record the incidence of delirium events at different time points after the intervention. Outcome measures included delirium events, the Visual Analogue Scale (VAS) scores, the Pittsburgh sleep quality index (PSQI) scores, the activities of daily living (ADL) scale scores, nursing satisfaction, and total nursing efficiency.

Results

Programmed comprehensive nursing was associated with significantly better nursing satisfaction, ADL scores, VAS scores, PSQI scores, and nursing efficiency than conventional nursing (all P < 0.05). Programmed comprehensive nursing resulted in a significantly lower incidence of postoperative delirium than conventional nursing (P < 0.05).

Conclusion

The application of programmed comprehensive nursing for postoperative delirium in ICU patients shows a promising efficiency, effectively alleviates the clinical symptoms of patients, and optimizes various clinical indicators of patients; hence, it is worthy of further application and promotion.

Multicomponent nursing program to prevent delirium in critically ill patients: a randomized clinical trial

OBJECTIVES

To determine the efficacy of a multicomponent nursing program to prevent delirium in critically ill patients.

METHODS

Parallel controlled randomized clinical trial to prevent delirium in 81 critically ill patients: 41 in the control group and 40 in the intervention group (intervention: spatial and temporal guidance, visual stimulus, auditive stimulus, and family support). Participants were recruited from September 2017 to March 2018 in the university hospital Los Comuneros, Bucaramanga, Colombia. Clinical Trials record NCT03215745.

RESULTS

The incidence of delirium was 5% in the intervention group and 24% in the control group. The relative risk was 0.20 (95% CI 0.05 to 0.88). The absolute risk reduction was 19.39% (95% CI 4.61 to 34.17) and the number needed to treat was 5 (95 CI % 3 to 26%).

CONCLUSION

The multicomponent nursing program is efficient to prevent delirium in critically ill patients.

Development and validation of a predictive score for ICU delirium in critically ill patients

Background

The incidence of delirium in intensive care unit (ICU) patients is high and associated with a poor prognosis. We validated the risk factors of delirium to identify relevant early and predictive clinical indicators and developed an optimized model.

Methods

In the derivation cohort, 223 patients were assigned to two groups (with or without delirium) based on the CAM-ICU results. Multivariate logistic regression analysis was conducted to identify independent risk predictors, and the accuracy of the predictors was then validated in a prospective cohort of 81 patients.

Results

A total of 304 patients were included: 223 in the derivation group and 81 in the validation group, 64(21.1%)developed delirium. The model consisted of six predictors assessed at ICU admission: history of hypertension (RR = 4.367; P = 0.020), hypoxaemia (RR = 3.382; P = 0.018), use of benzodiazepines (RR = 5.503; P = 0.013), deep sedation (RR = 3.339; P = 0.048), sepsis (RR = 3.480; P = 0.018) and mechanical ventilation (RR = 3.547; P = 0.037). The mathematical model predicted ICU delirium with an accuracy of 0.862 (P < 0.001) in the derivation cohort and 0.739 (P < 0.001) in the validation cohort. No significant difference was found between the predicted and observed cases of ICU delirium in the validation cohort (P > 0.05).

Conclusions

Patients’ risk of delirium can be predicted at admission using the early prediction score, allowing the implementation of early preventive interventions aimed to reduce the incidence and severity of ICU delirium.

Preoperative cardiac function parameters as valuable predictors for nurses to recognise delirium after cardiac surgery: A prospective cohort study

BACKGROUND

Delirium is a common postoperative complication after cardiac surgery. The relationship between delirium and cardiac function has not been fully elucidated.

AIMS

The aim of this study was to identify the association between preoperative cardiac function and delirium among patients after cardiac surgery.

METHODS

We prospectively recruited 635 cardiac surgery patients with a planned cardiac intensive care unit admission. Postoperative delirium was diagnosed using the confusion assessment method for the intensive care unit. Preoperative cardiac function was assessed using N-terminal prohormone of brain natriuretic peptide (NT-proBNP), New York Heart Association functional classification and left ventricular ejection fraction.

RESULTS

Delirium developed in 73 patients (11.5%) during intensive care unit stay. NT-proBNP level (odds ratio (OR) 1.24, 95% confidence interval (CI) 1.01-1.52) and New York Heart Association functional classification (OR 2.34, 95% CI 1.27-4.31) were both independently associated with the occurrence of delirium after adjusting for various confounders. The OR of delirium increased with increasing NT-proBNP levels after the turning point of 7.8 (log-transformed pg/ml). The adjusted regression coefficients were 1.19 (95% CI 0.95-1.49, P=0.134) for NT-proBNP less than 7.8 (log-transformed pg/ml) and 2.78 (95% CI 1.09-7.12, P=0.033) for NT-proBNP greater than 7.8 (log-transformed pg/ml). No association was found between left ventricular ejection fraction and postoperative delirium.

CONCLUSION

Preoperative cardiac function parameters including NT-proBNP and New York Heart Association functional classification can predict the incidence of delirium following cardiac surgery. We suggest incorporating an early determination of preoperative cardiac function as a readily available risk assessment for delirium prior to cardiac surgery.