EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Key words : Key words: Perioperative sleep, Delayed graft function, Renal transplantation, Immunosuppression, Patient outcomes

Sleep is adversely affected in the perioperative period and is intimately related to a patient’s postoperative recovery. Sleep deprivation results in a state of hyperalgesia, which is only reinforced by a subsequent interference and reduction in opioid analgesia efficacy. The distress that would result from inadequate pain control could also be compounded by sleep deprivations’ deleterious effects on mental state, promoting patient experiences of depression and anxiety. Inadequate pain control, mental state deterioration, and daytime somnolence from sleep deprivation may also affect discharge coordination. With poor postoperative sleep and its subsequent negative sequalae, the patient may not be able to engage in pharmacy education and would invariably retain less information than the well-rested patient. This may result in unintentional errors with medication compliance and potential harmful (over or under) use of immunosuppression agents in the community.

Perioperative sleep during transplant surgery not only has the potential to affect patient-related outcome and experience measures but may also affect biochemical indices of transplant success. Sleep deprivation adversely affects carbohydrate metabolism, which would only serve to reinforce the glucose intolerance already experienced by patients secondary to their significant perioperative immunosuppression. In addition, sleep deprivation can increase the risk of postoperative pneumonia, through a blunting of respiratory endurance, which again, in patients who have just received substantial immunosuppression, has the potential for adverse effects on their morbidity and mortality.

However, the unfortunate reality is that evidence is lacking on the effects of sleep in the acute, perioperative period specific to transplant surgery. Although reasonable parallels and inferences can be made on the aforementioned effects of perioperative sleep deprivation and transplant surgery, the relationship between sleep and perioperative transplant morbidity and mortality may not be so linear and predictable when the discussion shifts to graft function. Currently, no direct evidence is available on perioperative sleep and graft function. In a study of 83 participants, Zhang and colleagues reported mean total sleep time (in 24 hours on polysomnography) of only 135.5 minutes per night posttransplant; however, no analyses on graft function were undertaken. In other work that compared graft function after daytime versus nighttime surgical operations, no differences in graft function were shown; however, no data on patient sleep profiles were obtained.

The importance of perioperative sleep specifically in transplant surgery is secondary to its effects on the cardiorenal and immunological systems. Sleep affects renal hemodynamics, with reductions in total renal blood flow and urinary excretion of electrolytes, osmotically active particulates, and waste materials during sleep. Furthermore, sleep promotes the production of proinflammatory cytokines, the extravasation of T cells, their redistribution to secondary lymphoid tissues, and the interaction between antigen-presenting cells and T-helper cells. Therefore, sleep could potentiate immune interactions between donor and recipient tissue, influencing graft function and rejection. This hypothesis has been preliminarily supported by Ruiz and colleagues who demonstrated that undisturbed sleep (in mice) was accompanied by an increased (skin) allograft rejection compared with sleep deprivation. Conversely, reductions in delayed graft function have been observed in renal transplant patients who have received perioperative dexmedetomidine infusion. The benefits may have been secondary to attenuation of ischemia-reperfusion injury; however, this same drug has been shown to improve sleep by improving sleep efficiency, reducing fragmentation, increasing stage 2 sleep, and promoting the redistribution of sleep to occur during the night.

Although control of patient sleep may not be plausible or possible, the clinical environment and medication regimen can be adjusted to optimize a patient’s sleep hygiene. Because delayed graft function and slow graft function remain as major obstacles, with substantial implications on outcomes even 5 years posttransplant, every opportunity to improve the perioperative outcomes of transplant should be undertaken. Therefore, further research to characterize sleep of perioperative transplant patients, the effect of sleep on patient-related outcome and experience measures, and the relationship between sleep and graft function is strongly encouraged.

Volume: 22 Issue: 10 October 2024

FULL TEXT