Associations between ondansetron and the incidence of postoperative nausea and vomiting and food intake in Japanese female undergoing laparoscopic gynecological surgery: a retrospective study.

PURPOSE: Prevention of postoperative nausea and vomiting (PONV) is important to achieve DREAM (drinking, eating, mobilization). Ondansetron inhibits PONV, but its effects on postoperative food intake have not been investigated. This study aimed to examine associations between ondansetron and PONV incidence, and postoperative food intake. METHODS: This retrospective study included adult patients (n = 632) who underwent laparoscopic gynecological surgery at Kyushu University Hospital between January 2017 and June 2023. Outcomes were PONV on the day of surgery, PONV up to the day after surgery, and food intake, which was assessed for breakfast and lunch on the day after surgery. Odds ratios (ORs) for PONV incidence and postoperative no-food intake were calculated between those with and without ondansetron during surgery. Multivariable-adjusted analysis was performed using possible confounding factors for PONV. Synergistic effects of combining ondansetron with dexamethasone or total intravenous anesthesia (TIVA) were assessed. RESULTS: Multivariable-adjusted ORs for PONV on the day of surgery and up to the day after surgery were 0.56 (95% confidence interval, 0.32-0.99, p = 0.04) and 0.52 (0.30-0.93, p = 0.03), respectively, in the ondansetron group (n = 84) compared with the non-ondansetron group (n = 548). In contrast, multivariable-adjusted ORs for no-food intake of breakfast and lunch the day after surgery in the ondansetron group compared with the non-ondansetron group were not significant. Analysis of synergistic effects on PONV showed no significant interaction between ondansetron and dexamethasone or ondansetron and TIVA combinations. CONCLUSION: Ondansetron administration during surgery was significantly associated with decreased PONV risk but was not associated with food intake the day after surgery.

Neurological sedative indicators during general anesthesia with remimazolam.

BACKGROUND: The bispectral index (BIS) value during general anesthesia with the newly developed anesthetic remimazolam is reported to be relatively high; however, the reason for this and the appropriate indicator for assessing the sedation level during remimazolam anesthesia have not been determined. In this study, the level of sedation during general anesthesia with remimazolam was evaluated using several different indicators. METHODS: Thirty patients who underwent breast surgery under general anesthesia with remimazolam were included. BIS®, Sedline® and the pupil resting diameters were measured simultaneously. The intraoperative dose of remimazolam was adjusted to obtain a BIS in the range of 40-60; if a BIS < 60 could not be achieved, the intraoperative dose was increased up to the maximal dose of 2 mg/kg/h. RESULTS: The mean intraoperative BIS and patient state index (PSI) in all patients was 50.6 ± 9.1 and 43.0 ± 11.8, respectively. Five patients showed a mean intraoperative BIS > 60 and eight patients showed mean intraoperative PSI > 50. The mean intraoperative spectral edge frequency (SEF) of BIS® or Sedline® was 15.3 ± 2.5 Hz or 10.6 ± 3.0 Hz, each. The mean intraoperative resting pupil diameter was 1.7 ± 0.2 mm. There were no patients with awareness during anesthesia. CONCLUSIONS: Processed electroencephalograms (BIS and PSI), and SEF of BIS® were relatively high during anesthesia with remimazolam, but SEF of Sedline® or pupillary diameter could be a supportive indicator to confirm sedation level during remimazolam anesthesia.

Effects of forced air warming systems on the airflow and sanitation quality of operating rooms with non-laminar airflow systems.

BACKGROUND: : Previous studies have demonstrated that forced air warming (FAW) can be used safely in operating rooms with laminar airflow (LAF) ventilation systems. However, the effects of FAW on the airflow at surgical sites under non-LAF (nLAF) ventilation systems remain unclear, as nLAF systems generate outlet-to-inlet multidirectional airflows of the air conditioning system. Here, we evaluate the effects of FAW on the airflow and sanitation quality in surgical fields with nLAF ventilation systems. METHODS: : The airflow speed and direction were measured using a three-dimensional ultrasonic anemometer. Sanitation quality was evaluated by measuring the amount of dust particles after the activation of air conditioning. RESULTS: : FAW caused no meaningful airflow (> 10 cm/sec) and did not diminish the sanitation quality in the surgical field separated by the anesthesia screen. Above the head area, the upward FAW airflow was not counteracted by nLAF, which caused an upward airflow at the edges of the operating table, originating from outside of the operating table and the floor. CONCLUSIONS: : Sanitation quality was kept under FAW working even in an nLAF-equipped OR. According to the inlet/outlet layouts of nLAF, the upward FAW-induced airflow in the head area was not counteracted, and the upward airflow from the floor induced by the air conditioner outlet could be detected.