BackgroundGeneral anesthesia often produces some degree of hypothermia and hypothermia causes much more blood loss during surgery than normothermia. Electrically heated humidifiers (EHHs) have been used for patients under general anesthesia and in the intensive care unit. However, the benefits of the EHH have not been widely reported in the literature.MethodsPatients scheduled for posterior lumbar spine fusion, were randomly assigned to a mechanically ventilated with EHH circuit group or to a conventional respiratory circuit group. Their tympanic membrane temperature was monitored every 30 min after induction up to 180 min, and perioperative blood losses, transfusion requirements during surgery, and other complications were noted.ResultsPatients in the control group (n = 40) showed a lower mean body temperature at all times than immediately after induction, while the EHH group (n = 40) showed a lower body temperature from 60 minute after induction comparing to the initial temperature. Furthermore, patients in the EHH group had a higher mean body temperature than patients in the control group during surgery (35.9 ± 0.4 vs 35.4 ± 0.5, P < 0.001). Mean intraoperative blood loss (9.75 ± 5.4 vs 7.48 ± 3.9, P = 0.035) and transfusion requirements (57.5% vs 25%, P = 0.006) were significantly less in the EHH group, but postoperative blood loss, duration of hospitalization, and other complications were not significantly different in the two study groups.ConclusionsThe use of an electrically heated humidifier did not prevent a body temperature drop under general anesthesia. However, it helped maintain body temperature and was associated less blood loss and transfusion requirement during surgery.

BackgroundPostoperative nausea and vomiting (PONV) is common complication of Patient-Controlled Analgesia (PCA) after surgery. The authors sought to determine whether a transdermal scopolamine (TDS) patch in combination with IV dexamethasone is more effective than IV dexamethasone alone or IV dexamethasone plus IV ramosetron for reducing PONV in patients receiving epidural PCA after major orthopedic surgery.Methods120 patients that received epidural PCA with hydromorphone and ropivacaine after major orthopedic surgery under spinal anesthesia were allocated to 3 groups: Group D (n = 40) received IV dexamethasone 8 mg, Group DR (n = 40) received IV dexamethasone 8 mg plus IV ramosetron 0.3 mg, Group DS (n = 40) received IV dexamethasone 8 mg plus a TDS patch (Group DS, n = 40). Nausea and vomiting incidences, VAS for nausea, the use of additional antiemetics, and adverse effects (a dry mouth, blurred vision, drowsiness) during the first 24 hours postoperatively were subjected to analysis.ResultsThe DS Group had a significantly higher rate of complete remission of PONV than the D and DR groups (82.5% vs 47.5%, and 50.0%, respectively), and had lower rates of nausea (17.5% vs 55.0%, and 50.0%), and vomiting (10.0% vs 50.0%, and 25.0%), and required less antiemetics (5.0% vs 35.0%, 22.5%) than group D and Group DR during the first 24 hours after surgery. Furthermore, no inter-group differences were observed with respect to adverse effects in the three groups.ConclusionsThe prophylactic use of a TDS patch plus dexamethasone was found to be a more effective means of preventing PONV in patients that received epidural PCA after major orthopedic surgery than dexamethasone alone or dexamethasone plus ramosetron without adversely affecting side effects.