Incidence, risk factors, and cumulative risk of delirium among ICU patients: A case-control study

Intensive care nurses' perceptions and awareness of delirium and delirium prevention guidelines

BACKGROUND

Delirium is an acute and fluctuating disturbance of cognition and is a common occurrence in critically ill patients. It is a manifestation of an acute brain dysfunction often attributed to higher survival rates and a subsequently aging population. Intensive Care Unit (ICU) treatment and survival often contributes towards development of delirium, and lack of or inappropriate management can translate into the development of long-term psychological effects that last even after discharge. While a lot is already known about this topic, and several assessment tools exist, these are not being consistently used by ICU nurses and as a result delirium often goes unrecognized, with unwarranted consequences.

AIMS

The study aimed to explore the perception of delirium among ICU nurses, and the extent of their awareness about guidelines to assess and prevent delirium in ICU patients. It also sought to understand the application of delirium guidelines in ICU practice.

STUDY DESIGN

A quantitative, exploratory, self-reporting survey was conducted among 145 ICU nurses from one critical care unit in the Republic of Ireland.

RESULTS

The overall response rate was 71% (103/145). Most nurses (85%) who participated in this survey believed delirium was expected. However, only 45% acknowledged it is a complication. Only 31% of nurses monitored delirium using a validated scale and few observed this as a part of routine care. Most nurses had received education; however, this did not translate to their clinical practice.

CONCLUSIONS

Guidelines on managing delirium may not be routinely implemented in the ICU settings of hospitals in the Republic of Ireland.

RELEVANCE TO CLINICAL PRACTICE

As the findings suggest, a gap exists between theory and practice, necessary revision of policy or creating a new policy, supplemental educational sessions such as bedside sessions, e-learning module, study day or seminars need to be organized to improve nurses' awareness related to delirium and delirium prevention guidelines.

Patient Outcomes and Management Strategies for Intensive Care Unit (ICU)-Associated Delirium: A Literature Review

Delirium is a significant public health concern, with tremendous implications for patient outcomes. Intensive care unit (ICU)-related delirium is gaining attention due to the higher prevalence of delirium in ICU-admitted patients. The most common negative outcomes of ICU delirium include cognitive impairments, functional dependence, high incidence of mortality, extended stay in the ICU, and high costs. So far, no single etiological factor has been identified as the sole cause of delirium. Several functional, neurotransmitter, or injury-causing hypotheses have been proposed for ICU delirium. Several risk factors contribute to the development of delirium in patients admitted to the ICU. These are age, gender, types of sedation, physical restraints, medical and surgical interventions, pain, and extended stay in the ICU. The most commonly used assessment modules for ICU delirium are the PREdiction of DELIRium in ICu patients (PRE-DELIRIC), Early PREdiction model for DELIRium in ICu patients (E-PRE-DELERIC), and Lanzhou Model, Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), Intensive Care Delirium Screening Checklist (ICDSC), and Delirium Rating Scale (DRS). There is no proper treatment for ICU delirium; however, it can be managed through various pharmacological and non-pharmacological interventions. Healthcare providers should receive constant education and training on delirium recognition, prevention, and management to enhance patient care and outcomes in the ICU. Further research is needed on the effective prevention and management of ICU delirium.

Former smoking, but not active smoking, is associated with delirium in postoperative ICU patients: a matched case-control study

Objective

To examine the relationship between current and former smoking and the occurrence of delirium in surgical Intensive Care Unit (ICU) patients.

Methods

We conducted a single center, case-control study involving 244 delirious and 251 non-delirious patients that were admitted to our ICU between 2018 and 2022. Using propensity score analysis, we obtained 115 pairs of delirious and non-delirious patients matched for age and Simplified Acute Physiology Score II (SAPS II). Both groups of patients were further stratified into non-smokers, active smokers and former smokers, and logistic regression was performed to further investigate potential confounders.

Results

Our study revealed a significant association between former smoking and the incidence of delirium in ICU patients, both in unmatched (adjusted odds ratio (OR): 1.82, 95% confidence interval (CI): 1.17-2.83) and matched cohorts (OR: 3.0, CI: 1.53-5.89). Active smoking did not demonstrate a significant difference in delirium incidence compared to non-smokers (unmatched OR = 0.98, CI: 0.62-1.53, matched OR = 1.05, CI: 0.55-2.0). Logistic regression analysis of the matched group confirmed former smoking as an independent risk factor for delirium, irrespective of other variables like surgical history (p = 0.010). Notably, also respiratory and vascular surgeries were associated with increased odds of delirium (respiratory: OR: 4.13, CI: 1.73-9.83; vascular: OR: 2.18, CI: 1.03-4.59). Medication analysis showed that while Ketamine and Midazolam usage did not significantly correlate with delirium, Morphine use was linked to a decreased likelihood (OR: 0.27, 95% CI: 0.13-0.55).

Discussion

Nicotine's complex neuropharmacological impact on the brain is still not fully understood, especially its short-term and long-term implications for critically ill patients. Although our retrospective study cannot establish causality, our findings suggest that smoking may induce structural changes in the brain, potentially heightening the risk of postoperative delirium. Intriguingly, this effect seems to be obscured in active smokers, potentially due to the recognized neuroprotective properties of nicotine. Our results motivate future prospective studies, the results of which hold the potential to substantially impact risk assessment procedures for surgeries.

Incidence, Subtypes, Risk factors, and Outcome of Delirium: A Prospective Observational Study from Indian Intensive Care Unit

Background

Delirium is a common, under-recognized, and often fatal condition in critically ill patients, characterized by acute disorder of attention and cognition. The global prevalence varies with a negative impact on outcomes. A paucity of Indian studies exists that have systematically assessed delirium.

Objective

A prospective observational study designed to determine the incidence, subtypes, risk factors, complications, and outcome of delirium in Indian intensive care units (ICUs).

Patients and methods

Among 1198 adult patients screened during the study period (December 2019-September 2021), 936 patients were included. The confusion assessment method score (CAM-ICU) and Richmond agitation sedation scale (RASS) were used, with additional confirmation of delirium by the psychiatrist/neurophysician. Risk factors and related complications were compared with a control group.

Results

Delirium occurred in 22.11% of critically ill patients. The hypoactive subtype was the most common (44.9%). The risk factors recognized were higher age, increased acute physiology and chronic health evaluation (APACHE-II) score, hyperuricemia, raised creatinine, hypoalbuminemia, hyperbilirubinemia, alcoholism, and smoking. Precipitating factors included patients admitted on noncubicle beds, proximity to the nursing station, requiring ventilation, as well as the use of sedatives, steroids, anticonvulsants, and vasopressors. Complications observed in the delirium group were unintentional removal of catheters (35.7%), aspiration (19.8%), need for reintubation (10.6%), decubitus ulcer formation (18.4%), and high mortality (21.3% vs 5%).

Conclusion

Delirium is common in Indian ICUs with a potential effect on length of stay and mortality. Identification of incidence, subtype, and risk factors is the first step toward prevention of this important cognitive dysfunction in the ICU.

How to cite this article

Tiwari AM, Zirpe KG, Khan AZ, Gurav SK, Deshmukh AM, Suryawanshi PB, et al. Incidence, Subtypes, Risk factors, and Outcome of Delirium: A Prospective Observational Study from Indian Intensive Care Unit. Indian J Crit Care Med 2023;27(2):111-118.

Incidence, characteristics and risk factors of delirium in the intensive care unit: An observational study

AIMS AND OBJECTIVE

To investigate the incidence, characteristics and risk factors of delirium in the ICU.

BACKGROUND

Identifying the risk factors of delirium is important for early detection and to prevent adverse consequences.

DESIGN

An observational cohort study conducted according to STROBE Guidelines.

METHOD

The study was conducted with patients who stayed in ICU ≥24 h and were older than 18 years. Patients were assessed twice daily using the RASS and CAM-ICU until either discharge or death. Cumulative incidence was calculated. Demographic/clinical characteristics, length of stay and mortality were compared between patients with and without delirium. A logistic regression model was used to investigate risk factors.

RESULTS

The incidence of delirium was 31.8% and hypoactive type was the most frequent (41.5%). The median onset of delirium was 3 days (IQR = 2) with a mean duration of 5.27 ± 2.32 days. Patients with delirium were significantly older, had higher APACHE-II, SOFA and CPOT scores, higher blood urea levels, higher requirements for mechanical ventilation, sedation and physical restraints, longer stays in the ICU and higher mortality than those without delirium. The logistic regression analysis results revealed that a CPOT score ≥3 points (OR = 4.70, 95% CI: 1.05-20.93; p = .042), physical restraint (OR = 10.40, 95% CI: 2.75-39.27; p = .001) and ICU stay ≥7 days (OR = 7.26, 95% CI: 1.60-32.84; p = .010) were independent risk factors of delirium.

CONCLUSIONS

In this study, the incidence of delirium was high and associated with several factors. It is critical that delirium is considered by all members of the healthcare team, especially nurses, and that protocols are established for improvements.

RELEVANCE TO THE CLINICAL PRACTICE

Based on the results of this study, delirium could be decreased by preventing the presence of pain, prudent use of physical restraints and shortening the ICU stay.

Fatores de risco associados ao delirium em idosos hospitalizados para tratamento clínico

Objetivo: identificar fatores de risco associados ao desenvolvimento de delirium em pessoas idosas hospitalizadas para tratamento clínico. Método: revisão integrativa da literatura. Busca realizada em fevereiro de 2022 através da aplicação de estratégia de busca em portais e bases de dados eletrônicas, como a Biblioteca Virtual em Saúde, o PubMed/MEDLINE e o Web of Science. Resultados: a busca resultou em 965 artigos. Após retirada de duplicatas, 583 tiveram títulos e resumos lidos. Respeitados critérios de elegibilidade, chegou-se a 127 estudos para leitura completa, dos quais 110 foram excluídos e 17 analisados, totalizando amostra de 6.170 pacientes. Foram incluídos estudos com pacientes ≥ 60 anos de idade, tratamento clínico, avaliação de fatores de risco para delirium; e excluídos estudos que utilizaram instrumentos não validados, relatos de casos, teses, monografias, artigos de revisão ou que não responderam à questão de pesquisa. Os fatores de risco mais encontrados foram a presença de déficit cognitivo e demência. Outros fatores também encontrados foram: idade avançada, presença de febre/infecção, desidratação, déficit funcional, uso de psicotrópicos antes do internamento, severidade das doenças de base, polifarmácia, déficit visual, dor ao repouso, presença de diabetes mellitus, fragilidade e tempo de internamento na emergência. Conclusões: os estudos apontam diversos fatores de risco associados ao delirium e destacam a relevância do reconhecimento do delirium pela equipe assistencial. Ação rápida e eficaz na prevenção do delirium em idosos depende da sua identificação. A equipe de saúde deve estar atenta durante o cuidado de populações vulneráveis para que o rastreio de sinais, muitas vezes flutuantes, seja facilitado.

Incidence, Associated Factors, and Outcome of Delirium among Patients Admitted to ICUs in Oman

Background

The incidence of delirium is high up to 46.3% among patients admitted to ICU. Delirium is linked to negative patient outcomes like increased duration of mechanical ventilation use, prolonged ICU stay, increased mortality rate, and healthcare costs. Despite the importance of delirium and its consequences that are significant, there is a scarcity of studies which explored delirium in Oman.

Objectives

This study was conducted to assess the incidence of delirium, the association between the selected predisposing factors and precipitating factors with delirium, determine the predicators of delirium, and evaluate its impacts on ICU mortality and ICU length of stay among ICU patients in Oman.

Methods

A multicenter prospective observational design was used. A total of 153 patients were assessed two-times a day by bedside ICU nurses through the Intensive Care Delirium Screening Checklist (ICDSC).

Results

The results revealed that the delirium incidence was 26.1%. Regression analysis showed that sepsis, metabolic acidosis, nasogastric tube use, and APACHE II score were independent predictors for delirium among ICU patients in Oman and delirium had significant impacts on ICU length of stay and mortality rate.

Conclusion

Delirium is common among ICU patients and it is associated with negative consequences. Multidisciplinary prevention strategies should be implemented to identify and treat the modifiable risk factors.

Risk factors and a nomogram model for postoperative delirium in elderly gastric cancer patients after laparoscopic gastrectomy

Background

To evaluate the risk factors of postoperative delirium (POD) in elderly gastric cancer (GC) patients after laparoscopic gastrectomy and construct a predictive model.

Methods

Elderly GC patients undergoing laparoscopic gastrectomy were enrolled and grouped based on the status of POD development within postoperative 7 days. Independent risk factors were selected out by univariate and multivariate logistic regression analyses and then enrolled in the nomogram prediction model.

Results

A total of 270 elderly GC patients were enrolled, and POD occurred in 74 (27.4%) patients within postoperative 7 days. The results of multivariate regression analysis indicated that age (OR: 3.30, 95% CI: 1.41–6.85, P < 0.001), sleeping pills (OR: 1.87, 95% CI: 1.12–3.09, P = 0.012), duration of ICU stay (OR: 1.55, 95% CI: 1.02–2.37, P = 0.029), albumin/fibrinogen ratio (AFR) (OR: 1.74, 95% CI: 1.03–2.76, P = 0.019), and neutrophils/lymphocytes ratio (NLR) (OR: 2.12, 95% CI: 1.11–4.01, P = 0.016) were five independent risk factors for POD in elderly GC patients. The AUC of the constructed nomogram model based on these five factors was 0.807.

Conclusions

This study highlighted that age, AFR, NLR, sleeping pills taking, and duration of ICU stay were independent risk factors for POD, and the nomogram model based on these factors could effectively predict POD in elderly GC patients.

Delirium and neuropsychological outcomes in critically Ill patients with COVID-19: a cohort study

OBJECTIVE

To characterise the clinical course of delirium for patients with COVID-19 in the intensive care unit, including postdischarge neuropsychological outcomes.

DESIGN

Retrospective chart review and prospective survey study.

SETTING

Intensive care units, large academic tertiary-care centre (USA).

PARTICIPANTS

Patients (n=148) with COVID-19 admitted to an intensive care unit at Michigan Medicine between 1 March 2020 and 31 May 2020 were eligible for inclusion.

PRIMARY AND SECONDARY OUTCOME MEASURES

Delirium was the primary outcome, assessed via validated chart review method. Secondary outcomes included measures related to delirium, such as delirium duration, antipsychotic use, length of hospital and intensive care unit stay, inflammatory markers and final disposition. Neuroimaging data were also collected. Finally, a telephone survey was conducted between 1 and 2 months after discharge to determine neuropsychological function via the following tests: Family Confusion Assessment Method, Short Blessed Test, Patient-Reported Outcomes Measurement Information System Cognitive Abilities 4a and Patient-Health Questionnaire-9.

RESULTS

Delirium was identified in 108/148 (73%) patients, with median (IQR) duration lasting 10 (4-17) days. In the delirium cohort, 50% (54/108) of patients were African American and delirious patients were more likely to be female (76/108, 70%) (absolute standardised differences >0.30). Sedation regimens, inflammation, delirium prevention protocol deviations and hypoxic-ischaemic injury were likely contributing factors, and the most common disposition for delirious patients was a skilled care facility (41/108, 38%). Among patients who were delirious during hospitalisation, 4/17 (24%) later screened positive for delirium at home based on caretaker assessment, 5/22 (23%) demonstrated signs of questionable cognitive impairment or cognitive impairment consistent with dementia and 3/25 (12%) screened positive for depression within 2 months after discharge.

CONCLUSION

Patients with COVID-19 commonly experience a prolonged course of delirium in the intensive care unit, likely with multiple contributing factors. Furthermore, neuropsychological impairment may persist after discharge.