Hee Koo Yoo

Neuromuscular interactions between mivacurium and esmolol in rabbits

We compared the dose–response relationship and the neuromuscular blocking effects of mivacurium during infusions of esmolol in 40 anaesthetised rabbits. Train‐of‐four stimuli were applied every 10 s to the common peroneal nerve and the force of contraction of the tibialis anterior muscle was measured. Plasma cholinesterase activity decreased by 13% after esmolol infusion. The ED95 of mivacurium increased significantly from 29 (4.8) μgkg−1 with placebo to 61 (9.8) μgkg−1 during esmolol 100 μgkg−1.min−1, 49 (8.2) μgkg−1 during esmolol 300 μgkg−1.min−1 and 54 (7.3) μgkg−1 during esmolol 500 μgkg−1.min−1, respectively (p < 0.001). The duration of neuromuscular block with mivacurium 0.16 mgkg−1 was prolonged by 30% with esmolol due to diminished plasma cholinesterase activity (p < 0.05). Heart rate and mean arterial blood pressure decreased by 15% with esmolol (p < 0.05). The results of this study show that, in rabbits, esmolol decreased plasma cholinesterase activity, antagonised the neuromuscular blocking potency of mivacurium and prolonged its neuromuscular blocking effect.

Assessments of long-term filtration performance of degradable prefabricated geotextile drains

A smart geotextile for hydraulic end-use applications, such as filtration and drainage, has been manufactured. For filtration applications, biodegradable prefabricated vertical drains (PVDs) were fabricated using special conditioned geotextile filter and plastic cores to improve their degradability. Aliphatic polyester-based PVDs showed higher tensile strengths than starch-based PVDs. Biodegradable PVDs showed lower hydraulic properties than normal PVDs, however, the magnitude of the difference was not large. In terms of their chemical resistance and biodegradation, the biodegradable PVDs were better than typical PVDs. Compared to geonet composites, smart geotextiles could be the ideal geosynthetics for drainage applications on side sloping areas and for the protection of geomembranes in waste landfills.

Evaluation of Clay Added Nonwovens as Filter in Waste Landfill

In this, study, the yellow clays were added to the nonwoven geotextiles to improve the removal effects of the toxic and organic components of the leachate solutions which are very dangerous to the mens health. 4 types of functional nonwoven geotextiles were manufactured with the different composition of yellow clays. We applied these functional nonwoven geotextiles to the waste landfill fields as a filtration material of leachate solutions and tested tensile properties before/after application. Chemical and biological resistances of these nonwoven geotextiles were also evaluated and the amounts of absorptions of toxic and organic components were compared to the simply manufactured polyester nonwoven geotextiles.

Intraoperative Pulmonary Embolism: A case report

A 62 year old female patient was transferred to the operating room for open reduction and internal fixation of the left femur fracture under general anesthesia. At 15min. after femur tourniquet application, there were suddenly decreased oxygen saturation, end-tidal CO2 concentration and blood pressure. We suspected a pulmonary embolism, and attempted vigorous emergency treatment and intensive care including ventilator care, vasopressor drug use, pulmonary artery pressure monitoring. At the 5th day after intensive care unit, she was transferred to general ward and she discharged without any sequelae after 17th day postoperatively. (Korean J Anesthesiol 1997; 33: 187∼191)