The PLEM100 (Inbody Co., Ltd., Seoul, Korea) is a device for measuring phase lag entropy (PLE), a recently developed index for the quantification of consciousness during sedation and general anesthesia. In the present study, we assessed changes in PLE along with the level of consciousness during the induction of general anesthesia using propofol. PLE was compared with the bispectral index (BIS), which is currently the most commonly used index of consciousness. After obtaining Institutional Review Board approval and written informed consent, we enrolled 15 patients (8 men, 7 women; mean age: 37 ± 9 years; mean height: 168 ± 8 cm; mean weight; 68 ± 11 kg) undergoing nasal bone reduction. PLE and BIS sensors were attached simultaneously, and general anesthesia was induced via target-controlled infusion (TCI) of propofol. PLE and BIS scores were recorded when the calculated effect site concentration shown on the TCI pump was equal to the target concentrations of 1.5, 2.0, 2.5, 2.8, 3.0, 3.2, 3.4, and 3.5 μg/mL (and at each 0.1 μg/mL increase, thereafter). Observer's Assessment of Alertness/Sedation (OAA/S) scores were also recorded until unconsciousness was achieved. Throughout the anesthesia period, all pairs of PLE and BIS data were collected using data acquisition software. The partial correlation coefficients between OAA/S scores and PLE, and between OAA/S scores and BIS were 0.778 ( P < .001) and 0.846 ( P < .001), respectively. Throughout the period of anesthesia, PLE and BIS exhibited a significant positive correlation. The partial correlation coefficient prior to the loss of consciousness was 0.838 ( P < .001), and 0.669 ( P < .001) following the loss of consciousness. Intra-class correlation between the 2 indices was 0.889 ( P < .001) and 0.791 ( P < .001) prior and following the loss of consciousness, respectively. PLE exhibited a strong and predictable correlation with both BIS and OAA/S scores. These results suggest that PLE is reliable for assessing the level of consciousness during sedation and general anesthesia.

Elderly patients with femoral fractures are anticipated to endure the most pain caused by positional changes required for spinal anesthesia. To improve pain relief, we compared the analgesic effects of intravenous dexmedetomidine-ketamine and dexmedetomidine-fentanyl combinations to facilitate patient positioning for spinal anesthesia in elderly patients with proximal femoral fractures. Forty-six patients were randomly assigned to two groups and received either 1 mg/kg of intravenous ketamine (group K) or 1 μg/kg of intravenous fentanyl (group F) concomitant with a loading dose of dexmedetomidine 1 μg/kg over 10 minutes, then dexmedetomidine infusion only was continued at 0.6 μg/kg/h for following 20 minutes, and titrated at a rate of 0.2 to 0.6 μg/kg/h until the end of surgery. After completion of the infusion of either ketamine or fentanyl, the patients were placed in the lateral position with the fracture site up. The pain score (0 = calm, 1 = facial grimacing, 2 = moaning, 3 = screaming, and 4 = unable to proceed because of restlessness or agitation) was used to describe the pain intensity in each step during the procedure (lateral positioning, hip flexion, and lumbar puncture), and quality score (0 = poor hip flexion, 1 = satisfactory hip flexion, 2 = good hip flexion, and 3 = optimal hip flexion) was used to describe the quality of posture. Group K showed a median pain score of 0 (0-1), 0 (0–0) and 0 (0–0) in lateral positioning, hip flexion and lumbar puncture, respectively, while group F showed a score of 3 (2.75–3), 3 (2–3) and 0 (0–1), respectively. The pain score in lateral positioning (P < .0001) and hip flexion (P < .0001) was significantly lower in group K than group F. Group K showed the significantly higher quality scores of spinal anesthesia positioning (P = .0044) than group F. Hemodynamic adverse effects, such as bradycardia, hypotension, and desaturation, were not significantly different between the groups. The administration of dexmedetomidine-ketamine showed a greater advantage in reducing pain intensity and increasing the quality with patient positioning during spinal anesthesia in elderly patients with proximal femoral fractures, without any serious adverse effects.

Background The forced-air warming system has been commonly used to prevent hypothermia during surgery and anesthesia. Traditionally, forced-air warming blankets have been not only used to cover and warm up the patient but also placed under the patient to secure sufficient skin to warm up. However, many clinicians are oblivious to how the novel method of using a warming blanket affects a patient’s skin and often lack the knowledge and awareness needed for the appropriate use of forced-air warming systems. Case presentation : A 79-year-old man presented to the hospital for robotic proctectomy under general anesthesia. The forced-air warming system was used to prevent intraoperative hypothermia, with the forced-air warming blanket placed under the patient. The surgery lasted for 7 h, and the forced-air warming devices were continuously used for 5 h intraoperatively. The surgery was completed without any incidents. However, a low-temperature burn on the patient’s back along with a localized pressure ulcer on his right scapula was observed. Conclusions It should be noted that forced-air warming systems can cause skin complications. To minimize complications, they must be used correctly, and appropriate preventive methods should be considered. Fundamentally, the patient’s skin should be continuously monitored intraoperatively.