NOCTURNAL BODY MOVEMENTS AND HYPOXEMIA IN MIDDLE-AGED FEMALES AFTER LOWER ABDOMINAL-SURGERY UNDER GENERAL-ANESTHESIA - A STUDY WITH THE STATIC-CHARGE-SENSITIVE BED (SCSB)

Objective. The aim of this study was to evaluate the feasibility of th e static-charge-sensitive-bed (SCSB) combined with pulse oximetry (SpO (2)) for postoperative monitoring and to determine variables which cou ld be used for evaluating the quality of postoperative sleep and breat hing. Methods. The frequency of body movements and the perioperative b reathing abnormalities were assessed using the SCSB and pulse oximeter in 15 female ASA-class I-II patients undergoing elective lower abdomi nal surgery under general anesthesia. Anesthesia and control of postop erative pain followed standard practice. The patients were monitored d uring one preoperative and three consecutive postoperative nights. Mov ements were analyzed according to their duration and time interval. Th e effect of opioids was evaluated by measuring arterial oxyhemoglobin saturation (SpO(2)) with pulse oximetry for one hour before and two ho urs after administration of standard doses of oxycodone. Results. The total movement time per hour increased during the first postoperative night (p = 0.003). Conversely, periodic movement activity decreased si gnificantly during the three postoperative nights (p = 0.05, p < 0.001 , p = 0.007). The mean SpO(2) decreased during the first postoperative night (95.5% vs. 94.2%, p = 0.002), but returned to the preoperative level during the following nights. No episodes of apnea with significa nt oxygen desaturation (a decrease in SpO(2) >5%) were observed. Opioi d administration was associated with decreased mean SpO(2) (91.8% vs. 93.6%, p = 0.02), but did not lead to clinically significant hypoxemia (lowest observed SpO(2) 89.8%). Conclusions. Postoperative periodic m ovement activity was suppressed, but sleep remained fragmented with fr equent body movements. In our middle-aged non-obese females (ASA I-II) , no severe postoperative hypoxemia was observed during the three-nigh ts postoperative survey. Perioperative movement monitoring with the SC SB was a valuable tool in rejecting movement artefacts of SpO(2) and i n evaluating general sleep quality.