Effects of Remimazolam versus Sevoflurane on Hemodynamics in Patients Undergoing Coil Embolization of Cerebral Aneurysm: A Prospective Randomized Controlled Trial.

Background: Cerebral aneurysm coil embolization is often performed under general anesthesia to prevent patient movement and sudden high blood pressure. However, the optimal anesthetic agent remains uncertain. This study aimed to determine whether maintaining anesthesia with remimazolam in patients undergoing coil embolization could avoid hypotension or hypertension compared to sevoflurane. Methods: Thirty-three adult patients participated in this single-blinded, randomized controlled trial. Patients in Group R were induced and maintained with remimazolam, whereas those in Group S received propofol and sevoflurane. Results: The use of remimazolam significantly reduced the incidence of intraoperative hypotension events (33.3% vs. 80.0%; p = 0.010) but did not change the incidence of hypertension events (66.7% vs. 73.3%; p = 0.690). Patients in Group R maintained a significantly higher range of maximal (100.2 ± 16.6 vs. 88.1 ± 13.5 mmHg; p = 0.037) and minimal (69.4 ± 6.6 vs. 63.4 ± 4.8 mmHg; p = 0.008) mean arterial blood pressure than those in Group S during the intervention. Conclusions: This is the first study to demonstrate the feasibility of maintaining general anesthesia with remimazolam in patients undergoing cerebral aneurysm coil embolization. The findings suggest that remimazolam may maintains better hemodynamic stability, reducing the incidence of hypotensive events without compromising patient safety.

Reliability of Marked Scales on Intravenous Fluid Plastic Bags.

Precise fluid administration is important to prevent hypo- or hypervolemia. However, the accuracy of scales marked on intravenous (IV) fluid plastic bags had remained unknown. Ten 1 L sized IV crystalloids were prepared from each of three manufacturers (H, J, and D). At each scale, the actual volume of the IV fluid was measured. Differences with the measured volumes for each scale were investigated between the three manufacturers. All initial total volume was greater than 1 L. Except for the full-filled level, H overfilled, whereas J and D filled less. For J and D, the maximal differences between the scale and the measured volume were about 200 mL. Fluid volumes of each scale were significantly different among the three manufacturers (P < 0.001). It is inaccurate to measure the amount of fluid depending on the IV bag scales. Clinicians must use electronic infusion pumps for accurate fluid administration.

The Effects of Intravenous Fluid Viscosity on the Accuracy of Intravenous Infusion Flow Regulators.

Intravenous infusion flow regulators (IIFRs) are widely used devices but it is unknown how much the difference between the IIFR scale and the actual flow rate depends on the viscosity of the intravenous (IV) fluid. This study evaluated the effects of viscosity on the flow rate of five IV fluids (0.9% normal saline, Hartmann's solution, plasma solution-A, 6% hetastarch, and 5% albumin) when using IIFRs. The viscosity of crystalloids was 1.07-1.12 mPa·s, and the viscosities of 6% hetastarch and 5% albumin were 2.59 times and 1.74 times that of normal saline, respectively. When the IIFR scales were preset to 20, 100, and 250 mL/hr, crystalloids were delivered at the preset flow rate within a difference of less than 10%, while 6% hetastarch was delivered at approximately 40% of the preset flow rates and 5% albumin was approximately 80% transmitted. When delivering colloids, IIFRs should be used with caution.