Major surgery can lead to postoperative disturbances in sleep patterns with subjective deterioration of sleep quality according to patients' reports as well as objective alterations of sleep architecture, as recorded by polysomnography.
These disturbances include severe sleep fragmentation, rapid eye movement (REM) and slow wave sleep significant reductions in duration as well as an increase in non-REM sleep stages. Spontaneous awakenings are also frequently reported.
After the third or fourth postoperative day, there is a substantial rebound in total REM activity, with frequent reports of vivid nightmares.
Factors implicated in postoperative sleep disturbances include but are not limited to the severity of the surgical procedure, the neuroendocrine response to surgery, inadequate treatment of postoperative pain and external factors interfering with sleep, such as light, noise and therapeutic procedures.
There are no adequate data from current literature as to whether regional anesthesia is superior to general anesthesia regarding postoperative sleep quality in patients subjected to either mode of anesthesia. There have been a few studies evaluating the effect of regional anesthesia on postoperative sleep quality after orthopedic procedures, without however comparing regional to general anesthesia in this setting. preliminary data from these studies suggest that regional anesthesia can also lead to postoperative sleep disturbances during the first postoperative nights, such as causing a reduction of REM stage.
So, the aim of this study will be to assess the effect of two different anesthetic techniques (general versus regional) in patients subjected to a similar operative procedure (saphenectomy).
Patients taking part in the study will be evaluated regarding their preoperative sleep quality by the Pittsburgh Sleep Quality Questionnaire (PSQI). The PSQI examines seven components of sleep quality retrospectively over a period of four weeks: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction over the last month. The patient self-rates each of these seven areas of sleep. Scoring of answers is based on a 0-3 scale, whereby '3' reflects the negative extreme on the Likert scale. The global score is generated by summing up all seven component scores and ranges from 0 to 21, with higher values corresponding to reduced sleep quality.
Consequently, patients will be randomized to one of two groups: one group subjected to general anesthesia (maintenance with sevoflurane) and a second group subjected to combined spinal-epidural anesthesia Patients will be assessed postoperatively with sleep diaries regarding potential sleep disturbances while they will be subjected to a long-term assessment of sleep quality by the use of the PSQI one and three months postoperatively.
The clinical implications of this study lie in the fact that postoperative sleep disturbances can lead to postoperative hemodynamic instability, episodic hypoxemia and mental status deterioration, which can all untowardly affect the short and long-term postoperative outcome. It would be interesting to determine whether one of the two anesthetic regimes is superior to the other as far as postoperative disturbances in sleep architecture are concerned
