Delirium during Weaning from Mechanical Ventilation

Relationship between Nonhepatic Serum Ammonia Levels and Sepsis-Associated Encephalopathy: A Retrospective Cohort Study

Objectives

Nonhepatic hyperammonemia often occurs in patients with sepsis. Ammonia plays an essential role in the occurrence of hepatic encephalopathy. However, the relationship between nonhepatic serum ammonia levels and sepsis-associated encephalopathy (SAE) remains unclear. Thus, we aimed to evaluate the association between serum ammonia levels and patients with SAE.

Methods

Data of critically ill adults with sepsis who were admitted to the intensive care unit were retrieved from the Medical Information Mart for Intensive Care IV (MIMIC IV) between 2008 and 2019 and retrospectively analyzed. Data of patients with sepsis patients and serum ammonia not related to acute or chronic liver disease were not included.

Results

Data from 720 patients with sepsis were included. SAE was found to have a high incidence (64.6%). After adjusting for other risk factors, a serum ammonia level of ≥45 μmol/L (odds ratio (OR): 3.508, 95% confidence interval (CI): 2.336-5.269, p < 0.001) was found to be an independent risk factor for patients with SAE; moreover, as the serum ammonia level increased, the hospital mortality of SAE gradually increased in a certain range (serum ammonia <150 μmol/L). Serum ammonia levels of ≥45 μmol/L were associated with higher Simplified Acute Physiology Score II and Sequential Organ Failure Assessment (SOFA) scores in patients with SAE. Besides, our study found that patients with SAE used opioid analgesics (OR:3.433, 95% CI: 1.360-8.669, p = 0.009) and the SOFA scores of patients with SAE (OR: 1.126, 95% CI: 1.062-1.194, p < 0.001) were significantly higher than those without SAE.

Conclusions

Nonhepatic serum ammonia levels of ≥45 μmol/L evidently increased the incidence of SAE. Serum ammonia levels should be closely monitored in patients with sepsis.

Incidence and Risk Factors of Ventilator-Associated Pneumonia among Patients with Delirium in the Intensive Care Unit: A Prospective Observational Study

INTRODUCTION

The incidence and risk factors for ventilator-related pneumonia (VAP) in patients with delirium are deficient, and there is a lack of in-depth knowledge of the impact of VAP on outcomes in this population. We investigated the incidence, risk factors, and outcomes of VAP in patients with delirium.

MATERIALS AND METHODS

This prospective observational study was performed in a surgical ICU at Be'sat Hospital in Hamadan, Iran, between 2018 and 2019. A total of 108 patients with delirium were identified using the Confusion Assessment Method (CAM) for the ICU and Intensive Care Delirium Screening Checklist (ICDSC) and enrolled in this study. The association between VAP and delirium, risk factors, and outcomes (ICU length of stay and ICU mortality) for VAP were investigated using the Cox proportional hazards model and logistic and simple linear regression analyses with a 95% confidence interval.

RESULTS

Of 108 delirium patients, 86 patients (79.6%) underwent mechanical ventilation (MV) and 16 patients (18.6%) experienced VAP during ICU stay. The median onset of VAP was 6.5 (IQR 4.2-7.7) days after intubation. Delirium patients with VAP stayed longer in the ICU (21.68 ± 4.26 vs.12.93 ± 1.71, P < 0.001) and also had higher ICU mortality (31.25% vs. 0%, P < 0.001) than subjects without VAP. According to multivariate cox regression, the expected HR for VAP was 53.5% lower for patients with early-onset delirium than in patients with late-onset delirium (HR: 0.465, 95% CI: 0.241-0.894, P=0.022). However, the expected hazard for VAP was 1.854 times and 4.604 times higher in patients with longer ICU stay (HR: 1.854, 95% CI: 1.689-3.059, P=0.032) and in patients with a prolonged MV duration (HR: 4.604, 95%CI: 1.567-6.708, P=0.023).

CONCLUSION

According to the results, there seems to be an inverse relationship between early onset of delirium and VAP. This finding cannot be conclusively cited, and more studies in this filed should be conducted with a larger sample size. Furthermore, VAP in delirium patients is associated with increases in poor outcomes (higher ICU mortality) and the use of medical resources (longer stay in the ICU and MV duration).

Prolonged hospitalization is a risk factor for delirium onset: one-day prevalence study in Slovenian INTENSIVE CARE UNITS

Delirium is a clinical syndrome often underestimated in the intensive care units (ICU). The aim of this study was to determine the prevalence and factors that influence the onset of delirium. A questionnaire was sent to intensivists in Slovenian ICUs, who estimated the prevalence of delirious patients. The questionnaire consisted of demographic data, type of ICU, diagnosis, reason for admission to the ICU, type of anesthesia and surgery, clinical condition, type of supportive therapy, presence of delirium, data on discharge, transfers between departments or patient outcome on day 30. Patient consciousness was assessed by the Richmond Agitation-Sedation Scale (RASS) and the presence of delirium by the validated delirium-screening Confusion Assessment Method for the ICU (CAM-ICU). Replies received from intensivists included data on 103 patients. According to RASS ≥-3, the prevalence of delirium was 9.5% (7 out of 74 patients). There was no difference in the prevalence of delirium between surgical and medical ICU patients (p=0.388). Delirious patients had longer hospital stay (p=0.002) and ICU stay (p=0.032) compared to patients without delirium. All delirious patients survived until day 30, whereas 19 patients without delirium died (p=0.092). Logistic regression analysis dismissed any association of delirium with patient mortality (p=0.998). Age, gender, anesthesia, mechanical ventilation, and type of surgical procedure could not be evaluated as risk factors for delirium. In Slovenian ICUs, a lower proportion of delirium was observed, as reported from similar studies. Risk factors such as gender, age, mechanical ventilation, sedation, anesthesia, or department could not predict delirium. However, prolonged hospitalization of ICU patients could predict the onset of delirium, but the presence of delirium did not increase patient mortality.

The major risk factors for delirium in a clinical setting

OBJECTIVE

We aimed to determine the major risk factors for the development of delirium in patients at a single general hospital by comparison with a control group.

SUBJECTS AND METHODS

We reviewed the medical records of 260 delirium patients and 77 control patients. We investigated age, sex, and risk factors for delirium in the total delirium group (n=260), the delirium medical subgroup (n=142), and the delirium surgical subgroup (n=118). Logistic regression analysis adjusting for age and sex was performed to identify the odds ratio.

RESULTS

The mean age and the percentage of males were significantly higher in the delirium group compared with the control group (68.9 vs 54.3 years and 70% vs 41.6%, respectively). Risk factors for the delirium group were lower plasma albumin, hypertension, mechanical ventilation, and antipsychotic drug use. Plasma sodium level and hypertension were important risk factors for the delirium medical subgroup. Stroke history, hypertension, ICU care, and medication were important risk factors for the delirium surgical subgroup.

CONCLUSION

Lower plasma albumin, hypertension, mechanical ventilation, and antipsychotic drug use are important risk factors for delirium.

Recent Insights on Prevalence and Corelations of Hypoactive Delirium

Delirium is a complex neuropsychiatric syndrome which is common in all medical settings. It often goes unrecognized due to difficulties in the detection of its hypoactive variant. This review aims to provide an up-to-date account on recent research on hypoactive delirium (HD). Thirty-eight studies, which were conducted in various clinical settings, including the Intensive Care Unit (ICU), were included in this review. Those studies involved recent research that has been published during the last 6 years. Prevalence of HD was found to vary considerably among different settings. HD seems to be more common in critically ill patients and less common in patients examined by consultation-liaison psychiatric services and in mixed patient populations. The presence of HD in ICU patients was associated with higher short- and long-term mortality and other adverse outcomes, but no such association was reported in other settings. Research on other possible associations of HD with clinical variables and on symptom presentation yielded inconclusive results, although there is some evidence for a possible association of HD with benzodiazepine use. There are several methodological issues that need to be addressed by future research. Future studies should examine HD in the primary care setting; treatment interventions should also be the objective of future research.