Factors Associated with Delirium in COVID-19 Patients and Their Outcome: A Single-Center Cohort Study

Abstract

Background: A significant proportion of patients with coronavirus disease 2019 (COVID-19) suffer from delirium during hospitalization. This single-center observational study investigates the occurrence of delirium, the associated risk factors and its impact on in-hospital mortality in an Italian cohort of COVID 19 inpatients. Methods: Data were collected in the COVID units of a general medical hospital in the South of Italy. Socio-demographic, clinical and pharmacological features were collected. Diagnosis of delirium was based on a two-step approach according to 4AT criteria and DSM5 criteria. Outcomes were: dates of hospital discharge, Intensive Care Unit (ICU) admission, or death, whichever came first. Univariable and multivariable proportional hazards Cox regression models were estimated, and risks were reported as hazard ratios (HR) along with their 95% confidence intervals (95% CI). Results: A total of 47/214 patients (22%) were diagnosed with delirium (21 hypoactive, 15 hyperactive, and 11 mixed). In the multivariable model, four independent variables were independently associated with the presence of delirium: dementia, followed by age at admission, C-reactive protein (CRP), and Glasgow Coma Scale. In turn, delirium was the strongest independent predictor of death/admission to ICU (composite outcome), followed by Charlson Index (not including dementia), CRP, and neutrophil-to-lymphocyte ratio. The probability of reaching the composite outcome was higher for patients with the hypoactive subtype than for those with the hyperactive subtype. Conclusions: Delirium was the strongest predictor of poor outcome in COVID-19 patients, especially in the hypoactive subtype. Several clinical features and inflammatory markers were associated with the increased risk of its occurrence. The early recognition of these factors may help clinicians to select patients who would benefit from both non-pharmacological and pharmacological interventions in order to prevent delirium, and in turn, reduce the risk of admission to ICU or death.

Neutrophil to lymphocyte ratio and platelet to lymphocyte ratio as prognostic predictors for delirium in critically ill patients: a systematic review and meta-analysis

“…A total of 530 records were retrieved in the database search and manual search of citation list of articles. After the exclusion of duplicates and not relevant records, 24 studies [ 17 – 35 , 38 – 42 ] were included in the qualitative and qualitative analysis. A flow chart depicting the selecting process is shown in Fig.…”

“…This meta-analysis included 24 studies [ 17 – 35 , 38 – 41 , 43 ], 17 of which were retrospective [ 18 – 20 , 22 , 23 , 25 , 26 , 29 – 33 , 35 , 38 – 41 ] and seven prospective [ 17 , 21 , 24 , 27 , 28 , 34 , 43 ]. In terms of document language, all of the documents were written in English language.…”

“…Supplementary Material C presented the methodological quality assessment of all studies. In total, 23 research [ 17 – 35 , 38 – 41 ] examined NLR levels in delirious and non-delirious patients, seven studies [ 22 – 24 , 29 – 31 , 35 , 41 ] reported PLR levels in delirious patients versus non-delirious patients, and five studies reported diagnostic value of NLR in delirium, based on ROC curve analysis [ 19 , 21 , 28 , 39 , 40 ].…”

“…NLR levels in the delirious group were compared with those of the non-delirious group in 23 cohort studies [ 17 – 35 , 38 – 41 ] with 10,839 critically ill patients, of whom 2338 were diagnosed with delirium. Compared with the non-delirious group, the delirious group's NLR levels were significantly higher (WMD = 2.14; CI 95% = 1.48–2.80, p < 0.01).…”

“…In the subgroup analysis according to the type of critical condition, there were four studies on PCD [ 17 , 19 , 30 , 38 ], including 1488 patients with COVID-19 of whom 265 developed delirium, and four studies on PSD [ 20 , 27 , 28 , 33 ] including 2559 patients with stroke of whom 651 developed delirium, and nine studies on POD [ 21 , 22 , 25 , 26 , 29 , 31 , 34 , 40 , 41 ] including 4239 patients with stroke of whom 661 developed delirium. The NLR levels in patients of delirious group were significantly more than those of non-delirious group in studies on POD, PSD and PCD (WMD = 1.14, CI 95% = 0.38–1.91, p < 0.01, WMD = 1.38, CI 95% = 1.04–1.72, p < 0.001, and WMD = 4.22, CI 95% = 3.47–4.98, p < 0.001, respectively, Fig.…”