Preventing postoperative delirium

Abstract

Background: Delirium is a common complication in elderly hospitalized patients. It prolongs the length of hospital stay, raises costs, increases the workload of the nursing staff, and may necessitate transfer of the patient to a nursing home. The risk of postoperative delirium is particularly high in elderly patients with pre-existing cognitive deficits.

Methods: In an open study, we systematically assessed the frequency of postoperative delirium in patients over age 70 on two surgical wards of a general hospital. In a six-month "prevalence phase," from March to August 2011, we counted the number of patients with postoperative delirium, but did not initiate any intervention. Thereafter, in a ten-month "intervention phase" from September 2011 to June 2012, a nurse with special training in the management of delirium carried out an intervention involving component measures of the Hospital Elder Life Program (HELP) on one of the two wards, with the aim of preventing postoperative delirium. The patients on the other ward served as a control group.

Results: In the prevalence phase, 20.2% of all patients developed postoperative delirium (95% confidence interval [CI], 14.6-26.4). In the intervention phase, postoperative delirium arose in 20.8% (95% CI, 11.3-32.1) of the patients on the ward with no specific interventions, but in only 4.9% (95% CI, 0.0-11.5) of those on the ward where the intervention was carried out. The difference was presumably due to the measures initiated by the specially trained nurse, including validation, improvement of sleep, cognitive activation, early mobilization, improved sensory stimulation, and improved nutritional and fluid intake. Important predictors of postoperative delirium included a low score on the Mini-Mental State Examination, advanced age, and preoperative infection.

Conclusion: The frequency of postoperative delirium in elderly patients with cognitive deficits can be lowered with nursing measures carried out by a specially trained nurse, close postoperative supervision, and cognitive activation.

Figure

Patient grouping according to the analyses carried out: No patient received specific treatment for delirium prevention. For this reason, the data of those shown in the dark-olive boxes were used as a study sample (n = 178) to determine factors predictive of postoperative delirium. The patient groups in the dashed boxes (n = 114) were both treated during the same study period, so their data were used to determine the effect of intervention. ^*Patients admitted to the wards were included in the study if they were over 70 years old, showed no clinical signs of delirium, and were able to understand the study and consent to participate. Patients were excluded if they had advanced dementia if they were unable to give consent due to advanced dementia, if they were already suffering preoperatively from severe delirium, refused on principle to participate in any study, or were in the terminal stage of their disease