Adequate Dosage for Midazolam Premedication in Koreans / 대한마취과학회지

BACKGROUND: Midazolam is often used as an anxiolytic premedication before surgery. Although the sedative, anxiolytic, and amnestic properties of midazolam may be desirable before the induction of general anesthesia, respiratory function is impaired frequently by larger doses of midazolam. Therefore, we evaluated the adequate doses of midazolam premedication on anxiolytic and sedation without its serious side effects. METHODS: Eighty ASA I or II adult patients scheduled for elective minor surgery were randomly allocated to four groups according to premedication doses of midazolam. They were group 1: midazolam 0.05 mg/kg IM for lean body mass (LBM); group 2: midazolam 0.075 mg/kg IM for LBM; group 3: midazolam 0.1 mg/kg IM for LBM.; group 4: midazolam 0.125 mg/kg IM for LBM. Blood pressure, heart rate, bispectral index (BIS), oxygen saturation (SpO2), anxiety visual analogue scale (VAS), and observer's assessment of alertness and sedation (OAA/S) scores were measured before and at 30 minutes after midazolam premedication. The frequency of apnea, defined as a cessation of spontaneous respiration for more than 10 seconds, was recorded. Induction time and dose requirements in propofol-induced general anesthesia were recorded at the loss of opening their eyes on verbal command and eyelid reflex after starting the propofol infusion. Following intubation, blood pressure and heart rate were measured. RESULTS: The bispectral index and anxiety VAS was significantly decreaced in group 3 and group 4. However, oxygen saturation were significantly lower in group 4 compared with group 3. CONCLUSIONS: We concluded that group 3 (midazolam 0.1 mg/kg IM for LBM) is the proper premedication dosage for anxiolytic and sedation in Koreans without respiratory side effects.

Segmental Bioelectrical Impedance Analysis(SBIA) for Determining Body Composition / 대한지역사회영양학회지

A new bioelectrical impedance method has been developed and evaluated. The electrodes; were made of stainless steel and electrical interfaces were created by an upright subject gripping hand electrodes and stepping onto foot electrodes. Eight tactile electrodes were in contact with surfaces of both hands and feet; thumb, palm and fingers, front sole, and rear sole. Automatic on-off switches were used to change current pathways and to measure voltage differences for target segments. Segmental body resistances and whole body resistance(RWHOLE)were measured in 60 healthy subjects. Segmental resistances of right arm(RRA), left arm(RLA), trunk(RT), right leg(RRL) and left leg(RLL)were310.0+/-61.6 omega, 316.9+/-64.6 omega, 25.1+/-3.4 omega, 236.8+/-31.2 omega and 237.6+/-30.4 omega, respectively. Individual segmental impedance indexes(Ht2/RRA, Ht2/RT, and Ht2 /RLA) were closely related to lean body mass(LBM)as measured by densitometry ranged from r=0.925 to 0.960. Ht2/(RRA+RT+RLA) predicted LBM slightly better(r=0.969) than the traditional index, Ht2/RWHOLE(r=0.964), supporting the accuracy of the segmental measurement. A multiple regression equation utilizing Ht2/RRA, Ht2/RT and Ht2/RRL predicted LBM with r=0.971. Ht2/RRA term of the regression contributed to more than 40% of the LBM prediction, indicating that lean mass of arm represented whole body LBM more closely than other body segments. The new bioimpedance method was characterized by upright posture, eight tactile electrodes, segmental measurements and utilization of electronic switches in comparison with the traditional method. The measurement with this new method was extremely reproducible, quick and easy to use.

Bioelectrical Impedance Analysis (BIA) of the Estimation of Total Body Water and Lean Body Mass in Patients with Renal Failure / 대한신장학회잡지

Bioelectrical impedance analysis (BIA) was used to determine total body water (TBW) and lean body mass (LBM) in patients with renal failure. The body's electrical resistance (R) was measured by the voltage to current ratio, injecting an 800microA alternating current with a frequency of 50KHZ and detecting a voltage drop between the wrist and the ankle. Impedance index (Height2/Resistance) compared favorably with TBW measured by deuterium (D2O) dilution method as the reference, giving the correlation coefficient (r) of 0.966 and standard error estimation (SEE) of 2.71 liter. The index was compared with LBM determined by dual-energy x-ray absorptiometry (DEXA) as the reference, giving r of 0.970 and SEE of 3.00kg. The r of 0.985 and SEE of 2.15kg were found between the reference method. BIA appeared to have a somewhat lower accuracy than those of the reference method. However, it is a useful clinical tool for estimating body composition, because it is easy, rapid and non-invasive. The existing BIA method is based on an extremely simple conductor model of the body. The accuracy may be improved further, based on a more realistic model for the body.