**6. Summary**

*Perioperative Care for Organ Transplant Recipient*

with the duration of delirium [71]. The relative hazard of death is nearly four times greater if a patient has delirium for 3 days versus no delirium. Beyond mortality, delirium also impacts quality of life following recovery. Delirium has been shown to negatively impact long-term cognitive function [72]. A recent multicenter, prospective, cohort study of critically ill patients was evaluated to estimate the prevalence of long-term cognitive impairment after critical illness [2]. The study enrolled adults with respiratory failure or shock in the medical or surgical intensive care unit, evaluated them for in-hospital delirium, and assessed global cognitive and executive function 3 and 12 months after discharge with the use of the Repeatable Battery for the Assessment of Neuropsychological Status. The study showed that one out of four patients had cognitive impairment 12 months after critical illness that was similar in severity to that of patients with mild Alzheimer's disease. At 3 months, 40% of the patients had global cognition scores that were 1.5 standard deviations below the population means (similar to scores for patients with moderate traumatic brain injury), and 26% had scores 2 standard deviations below the population means (similar to scores for patients with mild Alzheimer's disease). Interestingly, the degree of cognitive impairment affected older and younger patients equally. A longer duration of delirium was independently associated with worse global cognition at 3 and 12 months (P = 0.001 and P = 0.04, respectively) and worse executive function at 3 and 12 months [2]. These data strongly support efforts to initiate cognitive rehabilitation programs for patients who suffer from delirium during the postoperative period to enhance functional

In regards to transplant specific outcomes in patients who suffer from delirium, Lescot et al. examined postoperative outcomes for patients with and without delirium following liver transplant [18]. Patients who suffered from delirium after liver transplant had higher rates of sepsis during the intensive care unit stay (18 vs. 1.2%, P ≤ 0.001), longer days requiring mechanical ventilation (2 vs. 1,

P ≤ 0.001), longer intensive care unit length of stay (9 vs. 4 days,

however, it is clear that delirium is associated with worse outcomes.

mortality for patients who did not suffer from delirium [9].

Network and linked to Medicare claims by the US Renal Data System [9].

Haugen et al. recently evaluated 125,304 adult kidney transplant recipients between 1999 and 2015 as reported to the Organ Procurement and Transplantation

International Classification of Diseases 9 codes for delirium were identified from inpatient claims throughout the entire set of initial kidney transplant hospitalizations. Haugen and colleagues showed that delirium in kidney transplant recipients significantly associates with patient survival, with an approximately 40% mortality at 5 years for patients who developed delirium post transplant compared to 10%

P ≤ 0.001), and longer hospital length of stay (37 vs. 20 days, P ≤ 0.001). In addition, patients who developed delirium had increased mortality compared to those patients who did not suffer from delirium, both in the short-term as well as at 1 year following transplant (intensive care unit mortality: 10.7 vs. 2%, P = 0.04; in-hospital mortality: 25 vs. 6%; 1 year mortality: 32 vs. 12%, P = 0.007) [18]. A recent prospective cohort study to evaluate postoperative delirium after liver transplantation showed that 45% of recipients experience delirium with a median duration of 5 days [8]. Furthermore, postoperative delirium was associated with a four-fold increase in intensive care unit length of stay, a more than two-fold increase in hospital length of stay, and decreased survival probability at 1 year. The authors suggest that postoperative delirium should be considered a preventable clinical complication, and not just a predictive risk factor for worse outcomes in the liver transplant population [8]. Postoperative complications likely contribute to both increased rates of delirium and mortality,

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outcomes.

Delirium is a common clinical diagnosis in the solid organ transplant population. Delirium is under diagnosed, yet the recent appreciation of its impact on cognitive recovery indicates it is vital make efforts to mitigate its development and recognize it in a timely fashion to optimize transplant outcomes. Delirium has been shown to be associated with a longer length of stay, increased medical costs, increased morbidity/mortality and decreased cognitive function following hospital discharge. Non-pharmacologic preventive strategies, routine delirium screening, and performing a comprehensive evaluation for an underlying medical cause of delirium with prompt treatment are the cornerstones of delirium management. With a better understanding of the negative impact on both short and long term outcomes associated with delirium in the transplant population, a focused, multidisciplinary approach to delirium prevention and management strategies to decrease the prevalence and minimize duration of delirium is paramount in transplant recipients. Delirium should no longer be viewed as an unavoidable clinical complication in transplant patients. Instead, proactive measures for cognitive prehabilitation in high risk transplant candidates, together with the use of clinical prevention bundles and post-delirium rehabilitation programs are key components of maximizing patient survival and functional outcomes following solid organ transplantation.
