新型全固态阿托品电极的研制

制备了以脲醛树脂为框架,以KCl粉末为活性组分的Ag/AgCl固体电极。以此固体电极为基体,以阿托品—四苯硼酸根离子缔合物为活性物质,研制了一种新型全固态阿托品选择电极。并对此电极的性质进行了研究,结果表明该电极稳定性较好,并能用于硫酸阿托品制剂的含量测定。     

Determination of the analgesic dose–response relationship for epidural fentanyl and sufentanil with bupivacaine 0.125% in laboring patients

Study Objective: To establish the analgesic effective doses as defined as a visual analog pain scale (VAS) of at least 10 for 95% of parturients (ED₉₅) receiving either epidural fentanyl or sufentanil with bupivacaine 0.125% for labor analgesia.

Design: Double-blind, randomized controlled study.

Setting: Two tertiary-care teaching hospitals.

Patients: 100 female patients, at full-term pregnancy, in active early labor (<5 cm cervical dilation) and requesting obstetric anesthesia services for labor analgesia.

Interventions: Patients were randomized and equally distributed to receive one of ten epidural dosing regimens of bupivacaine 0.125% alone or with either fentanyl 25, 50, 75, or 100 μg or sufentanil 5, 10, 15, 20, or 25 μg in a 10-ml bolus after a 3-ml test dose of bupivacaine 0.25%.

Measurements and Main Results: VAS scores were obtained from each parturient using a 10-cm plastic VAS slide rule at times 0, 1, 5, 10, 15, 20, 25, and 30 minutes, and then again when the patient requested additional analgesia. Analgesic duration and demographic and obstetric data also were obtained. Using a log-probit dose–response analysis, analgesic success as defined as a VAS of at least 10 with each opioid dose was plotted and an ED₉₅ value of 8 μg and 50 μg was established for sufentanil and fentanyl, respectively, in bupivacaine 0.125%. No statistical difference was detected for analgesic duration or incidence of side effects between analgesic groups.

Conclusions: Epidural analgesia with fentanyl and sufentanil in bupivacaine 0.125% behaves in a dose–response fashion allowing for the determination of equipotent dose of each.     

Grade I hydronephrosis: pulsed Doppler US evaluation

This study was undertaken to determine whether the presence of blood vessels could mimic the appearance of grade I hydronephrosis on sonograms and thus cause false-positive readings. One hundred consecutive patients with grade I hydronephrosis were examined. Sample volumes were obtained with pulsed Doppler ultrasonography (US) at the site of the greatest separation of the central renal sinus echoes to determine if the separation was fluid accumulating in the collecting system, as in obstruction, or if the separation was actually caused by vessels that mimic hydronephrosis. Vascular structures accounted for the separation of the sinus echoes in 43% of patients. In patients 12 years of age or younger, this frequency rose to 61%. The simple procedure of evaluating the renal sinus echo separation with pulsed Doppler US should decrease the frequency of false-positive diagnoses of hydronephrosis and thus diminish the need for further confirmatory testing.     

Lower-extremity deep venous thrombosis: further experience with and refinements of US assessment

During a 1-year period, 537 compression ultrasound (CU) examinations were performed in 506 extremities of 485 patients for evaluation of possible deep venous thrombosis (DVT). Decisions regarding therapy were based on the result of this test in both outpatients and inpatients. Doppler ultrasound was also used during the last 7 months of the study, but this procedure did not alter the results obtained with CU alone. Incidental findings (eg, Baker cysts, aneurysms, and lymph nodes) were noted in 42 patients and were thought to be nonthrombotic causes of leg swelling or pain that could not be detected with venography. The reliability and clinical acceptance of CU as a means of diagnosing lower-extremity DVT resulted in a 50% yearly reduction in venography, with a concomitant 130% increase in the number of cases of DVT diagnosed.     

Radiation dose to small infants from single-photon absorptiometry

The radiation dose to the patient resulting from single-photon absorptiometry (SPA), now a widely used method for measuring bone mineral content (BMC) in vivo in infants and children, was evaluated. Lithium fluoride chips were placed on a phantom with a BMC in the small infant range (60 and 145 mg/cm). Measurement procedures mimicked the actual clinical sequence. The radiation exposure for a single BMC measurement is 46-70 mrad (460-700 microGy) to the forearm surface and 25-38 mrad (250-380 microGy) and 125-190 mrad (1,250-1,900 microGy) to the bone marrow and the bone, respectively. When eight repeated measurements are performed over a 1-year period, the radiation dose is about 368-560 mrad (3,680-5,600 microGy) to the forearm surface and 200-305 mrad (2,000-3,050 microGy) and 1,000-1,525 mrad (10.0-15.25 mGy) to the bone marrow and the bone, respectively. Even though the radiation dose is small, this method should be used only in well-designed clinical studies.