Intra-operative events during cardiac surgery are risk factors for the development of delirium in the ICU

Abstract

BackgroundRisk factors for delirium following cardiac surgery are incompletely understood. The aim of this study was to investigate whether intra-operative pathophysiological alterations and therapeutic interventions influence the risk of post-operative delirium.MethodsThis retrospective cohort study was performed in a 12-bed cardiosurgical intensive care unit (ICU) of a university hospital and included patients consecutively admitted after cardiac surgery during a 2-month period. The diagnosis of delirium was made clinically using validated scores. Comparisons between patients with and without delirium were performed with non-parametric tests. Logistic regression was applied to identify independent risk factors. Results are given as number (percent) or median (range).ResultsOf the 194 consecutive post-cardiac surgery patients, 50 (26 %) developed delirium during their ICU stay. Univariate analysis revealed that significant differences between patients with and without delirium occurred in the following intra-operative variables: duration of cardiopulmonary bypass (184 [72–299] vs 113 (37–717) minutes, p < 0.001), lowest mean arterial pressure (50 [30–70] vs 55 [30–75] mmHg, p = 0.004), lowest haemoglobin level (85 [56–133] vs 98 [53–150] g/L, p = 0.005), lowest body temperature (34.5 [24.4–37.2] vs 35.1 [23.9–37.2] °C, p = 0.035), highest noradrenaline support (0.11 [0.00–0.69] vs 0.07 [0.00–0.42] μg/kg/minute, p = 0.001), and frequency of red blood cell transfusions (18 [36 %] vs 26 [18 %], p = 0.018) and platelet transfusions (23 [46 %] vs 24 [17 %], p < 0.001). Only platelet transfusions remained an independent risk factor in the multivariate analysis (p < 0.001).ConclusionsIn patients undergoing cardiac surgery, various intra-operative events, such as transfusion of platelets, were risk factors for the development of a post-operative delirium in the ICU. Further research is needed to unravel the underlying mechanisms.

A hospital-wide evaluation of delirium prevalence and outcomes in acute care patients - a cohort study

“…Delirium is a sudden acute mental change accompanying acute illness. Characterized by disturbances of consciousness, attention, cognition, psychomotor behavior and emotions [ 1 , 2 ], it affects 10 to 60% of all patients treated in medical, surgical, medical-surgical mixed or general wards [ 3 – 5 ], and up to 80% of those treated in intensive care units (ICUs) [ 3 , 6 – 10 ]. More than two dozen predisposing and precipitating delirium risk factors have been identified, including male gender, older age (> 65 years), prior delirium, co-morbidities (i.e., dementia, depression) and severe illness [ 3 , 11 – 13 ].…”

The Prevalance Of Delirium After Open Heart Surgery And The Efficacy Of Dexmedetomidine

“…Rudiger ve ark. [25] deliryum gelişen hastalarda intraoperatif ve postoperatif vazoaktif ilaç kullanımının daha yüksek oranda olduğunu bildirmişlerdir.…”

Finally Getting the “Attention” It Deserves

“…Many of these factors, including lowest mean arterial pressure, lowest hemoglobin, lowest body temperature, highest inotropic support level and frequency of transfusion also have been implicated as risk factors for POD after cardiac surgery. 15 Finally, and most importantly, due to the retrospective nature of the study, unfortunately it was not possible to draw meaningful conclusions regarding the effect size of interventions on the incidence, duration, or burden of POD. Thus, while the results from this study help identify patients at risk of POD, it is not certain that identifying these patients ahead of time will lead to any reductions in the incidence, duration, or severity of POD.…”