[Postoperative delirium in the critically ill]

Delirium in elderly postoperative patients: A prospective cohort study

AIM

To describe the incidence, time in days and risk factors for postoperative delirium in elderly patients.

DESIGN

Prospective cohort study.

METHODS

Patients over 65 years were daily screened with the 4A's Test and the Delirium Observation Screening Scale for postoperative delirium. A psychiatrist assessed according to the DSM-V. We performed descriptive and logistic regression analyses.

RESULTS

From 202 patients, 7.5% (N = 15) had a diagnosed postoperative delirium, whereby 73.3% (N = 11) developed the delirium during the first 48 hr after surgery. The median duration was 1 day. Patients over 80 years suffering from heart failure with surgical drains, bladder catheter, central venous catheter had higher odds for developing a postoperative delirium. The incidence of postoperative delirium in our sample was lower compared with other surgical and ortho-geriatric populations. Despite age, several modifiable postoperative factors were associated with the occurrence of postoperative delirium.

Acute Confusional States in Hospital

BACKGROUND

Acute confusional state (delirium) is an acute disturbance of brain function. The incidence of such states varies according to the group of patients con- cerned: it ranges from 30% to 80% among patients in intensive care and from 5.1% to 52.2% among surgical patients, depending on the type of procedure. The earlier German term "Durchgangssyndrom" (usually rendered as "transitory psychotic syn- drome") tended to imply a self-limited and thus relatively harmless condition. In fact, however, delirium is associated with longer hospital stays, poorer treatment out- comes, and higher mortality. Approximately 25% of patients who have experienced an acute confusional state have residual cognitive deficits thereafter.

METHODS

This review is based on publications retrieved by a selective search in MEDLINE, PubMed, the Cochrane Library, and in the International Standard Randomised Controlled Trial Number (ISRCTN) registry.

RESULTS

Validated instruments are available for the reliable diagnosis of an acute confusional state, e.g., the Confusion Assessment Method for the ICU (CAM-ICU) for patients in intensive care and the 3D-CAM or CAM-S for patients on regular hospital wards. The prevention and treatment of this condition are achieved primarily by a nonpharmacological, multidimensional approach including early mobilization, reorientation, improvement of sleep, adequate pain relief, and the avoidance of polypharmacy. A meta-analysis has shown that these measures lower the incidence of delirium by 44%. The authors find no basis in the current literature for recommending prophylactic medication, although current data promisingly suggest that the incidence of delirium in surgical patients can be lowered by the perioperative administration of dexmedetomidine (odds ratio 0.35). The pharmaco- therapy of acute confusional states involves a careful choice of drug based on the clinical manifestations in the individual case.

CONCLUSION

The key elements of success in the treatment of acute confusional states in the hospital are adequate prevention, rapid diagnosis, the identification of precipitating factors, and the rapid initiation of both causally oriented and symptom- directed treatment.

Predictors of Postoperative Cognitive Decline in Very Old Patients With Hip Fracture: A Retrospective Analysis

BACKGROUND

To investigate incidence and predictors of the various postoperative cognitive declines in old patients with hip fracture.

METHODS

This retrospective chart study evaluated 411 patients (age ≥80 years, follow-up 5 years). After exclusion of 82 patients (preexisting dementia or delirium), 70 patients showing either diagnosed postoperative delirium (POD; group 1; N = 18, 5.5%) or an unspecified cognitive dysfunction and behavior (group 2; N = 52, 15.8%) were analyzed and compared with those without any acute postoperative cerebral impairment (control group; N = 259, 78.7%). Medical history, anesthesiological, orthopedic, and rehabilitation data were assessed using the medical database of the hospital information system. Relative ratio was calculated with Fisher exact test: P value Bonferroni corrected ≤.003.

RESULTS

Acute cognitive complications were observed in 70 (21.3%) patients. Our data in group 1 showed that patients with a medical history of stroke (relative risk [RR] = 16.2, P = .0001) or nicotine abuse (RR = 14.4, P = .001) and perioperative surgical bleeding (RR = 6.54, P = .002) are more likely to develop POD. Unspecified cognitive dysfunction and behavior (group 2) was significantly associated with a medical history of stroke (RR = 12.5, P = .0001) and postoperatively with depression (RR = 3.32, P = .001). In the follow-up, significantly more patients in group 1 (55.6%, RR = 21.8, P = .0001) and group 2 (13.5%, RR = 3.88, P = .001) developed dementia as compared to controls (1.9%). Mortality did not differ significantly between the groups (group 1: RR = 1.75, P = .5 and group 2: RR = 0.66, P = 1.0).

CONCLUSION

These data show that various predictors can identify a greater likelihood of developing postoperative cognitive decline in very old patients with hip fracture. Not identifying or labeling of POD limits the opportunity for evaluation, treatment, and planning. Thus, routine cognitive assessments need to be performed in the scope of multidisciplinary orthogeriatric comanagement.

[Dexmedetomidine]

Dexmedetomidine is a highly selective α2-receptor agonist with sedative, analgetic and anxiolytic effects. It is chemically related to clonidine and has been an authorized drug in Europe since September 2011. Dexmedetomidine enables a level of sedation in which mechanically ventilated patients may be woken by verbal stimulation (Richmond agitation sedation scale RASS 0--3). In this respect dexmedetomidine achieves the same desired effect as propofol and midazolam; however, in direct comparison to a sedation regime with benzodiazepines, dexmedetomidine reduces the prevalence, duration and severity of delirium in intensive care. Patients sedated by dexmedetomidine can statistically be extubated earlier and an influence on duration of stay in the intensive care unit (ICU) has not been shown. Daily therapy costs are approximately 5 times higher than those of propofol but an objective standpoint in relation to clinical cost efficiency is unattainable.

[Long-term consequences of postoperative delirium]

A patient reported anxiety and sleeping problems 9 months after reconstruction of the anterior floor of the mouth following tumor surgery. These symptoms had been initiated by a postoperative delirium with hallucinations, which had not been detected during its occurrence. One session of psychotherapy 9 months later reduced the symptoms. Patients in intensive care units should be asked and informed about delirium symptoms. This might prevent long-term psychological distress.

[Delirium in the elderly]

Delirium is a common, serious medical and often life-threatening condition in elderly in-patients. Delirium can develop primarily or secondarily related to other medical conditions and lead to hospital admission. The pathogenesis is still not fully known and is usually addressed as multifactorial. Alterations in neurotransmitters have a key role in this process. The incidence varies by setting up to 90%. Delirium is associated with increased short- and long-term mortality, iatrogenic complications, functional decline, and future development of cognitive impairment or dementia. Delirium is also associated with longer hospital stays, higher hospital and total health system costs, and an increasing rate of nursing home admissions. A structured diagnostic and therapeutic process is recommended. Delirium should become a quality indicator for hospital medicine; however, many research questions still exist.