Nalbuphine after major gynecologic surgery. Comparison of patient-controlled analgesia and intramuscular injections

A randomized investigation compared the efficacy and safety of nalbuphine administered by two methods, a patient-controlled infuser system and intramuscular (IM) injections, after major gynecologic surgery. Forty-seven patients were randomly assigned to receive nalbuphine by either method. The 22 patients using the infuser were given a 2.0-mg, incremental dose with a 10-minute lock-out interval between doses. A similar group receiving 10-15 mg IM every three hours served as the control. Misprogramming, overdosage, depressed respiration and drug dependence were not encountered. Self-administration provided equally satisfactory sedation and more immediate pain relief without painful injections. Although patients with the infuser had the ability to self-administer more medication, they did not use higher doses of nalbuphine than did the IM group. The additional cost of the infuser system was offset by the satisfaction expressed by the patients and by the improved nursing efficiency. Nalbuphine administered with a patient-controlled infuser provided an effective balance between analgesia and sedation and offered advantages over IM injections.

Electroencephalographic quantitation of opioid effect: comparative pharmacodynamics of fentanyl and sufentanil

The authors compared the pharmacodynamics of sufentanil with those of fentanyl using the electroencephalogram (EEG) as a measure of opioid drug effect. Sixteen patients were given a rapid infusion of sufentanil (18.75 micrograms/min) during EEG recording. To quantitate the opioid-induced slowing of the EEG, the authors analyzed its power spectrum and calculated the spectral edge. An inhibitory sigmoid Emax model of the maximal decrease in spectral edge produced by the opioid related spectral edge values to serum concentrations of sufentanil. The resulting data for the pharmacodynamic parameters of sufentanil were compared with fentanyl parameters that were obtained by reanalysis from an identically conducted, previously published study. The half-time of blood-brain equilibration (T1/2Keo) was not statistically different between sufentanil and fentanyl (6.2 +/- 2.8 vs. 6.6 +/- 1.7 min, mean +/- SD, respectively). The intrinsic potency of sufentanil, as measured by the serum concentration needed to cause half the maximal EEG slowing (IC50), was 12-fold greater (0.68 +/- 0.31 ng/ml) than that of fentanyl (8.1 +/- 2.2 ng/ml). The second part of the study verified the hypothesis that administration of equipotent bolus doses would produce equal onset times. Bolus injections of either 125 micrograms of sufentanil or 1,250 micrograms of fentanyl were given during EEG recording. The time from injection to 50% maximal EEG slowing (T50) was calculated for each patient. The values for T50 for the two groups did not differ. The authors conclude that fentanyl and sufentanil have similar pharmacodynamic profiles, the former being 12 times more potent than the latter.

Pharmacokinetics of fentanyl administered by computer-controlled infusion pump

Fentanyl was administered to 21 patients using a computer-controlled infusion pump (CCIP) based on a pharmacokinetic model. Eleven of the patients were dosed according to the pharmacokinetics described by McClain and Hug, and ten of the patients were dosed according to the pharmacokinetics described by Scott and Stanski. The authors measured the difference between the measured arterial fentanyl concentrations and the concentrations predicted by the CCIP for each pharmacokinetic parameter set. The median absolute performance error (MDAPE) in patients dosed according to McClain and Hug's parameters was 61%, and the MDAPE in patients dosed according to Scott and Stanski's parameters was 33%. The population pharmacokinetics in these 21 patients were analyzed using a pooled data technique. The pharmacokinetics of fentanyl in this population showed a smaller central compartment volume and a more rapid initial distribution half-life than previously estimated for fentanyl. The derived pharmacokinetic parameters described these patients well and also predicted the observed fentanyl concentrations from four previously published fentanyl studies with reasonable accuracy. Comparison of the parameters used by the authors with those of McClain and Hug demonstrated that dosing regimens designed from pharmacokinetic models can be fairly accurate at the times sampled in the original study but may not be accurate at time points not sampled in the original research. The authors concluded that although the pharmacokinetics of fentanyl administered by CCIP are the same as the pharmacokinetics of fentanyl administered by a bolus or constant rate infusion, a pharmacokinetic study using a CCIP may be particularly effective at characterizing the most rapid distribution pharmacokinetic parameters, and thus may provide parameters appropriate for subsequent use in a CCIP.

Osteoporosis and hip fractures

Epidemiologic studies have contributed to our understanding of osteoporosis through identification of groups at high risk of fracture and through discernment of factors associated with increased risk of low bone density and fracture. Many of the questions remaining can be addressed only through the use of epidemiologic methods in human populations. These include longitudinal studies in large cohorts to better delineate factors associated with bone loss and fracture and randomized clinical trials to adequately assess therapies. Particularly needed are studies in adolescents to assess determinants of peak bone mass and the effect of subsequent bone loss with aging.

Evaluation of a nonisotopic probe for detection of Chlamydia trachomatis in endocervical specimens

A nonisotopic probe (Gen-Probe PACE; Gen-Probe, Inc., San Diego, Calif.) for detection of Chlamydia trachomatis in endocervical specimens was evaluated in 344 women attending a dysplasia clinic or an obstetrics clinic and 158 women who visited an emergency room. For each patient, the probe, a tissue cell culture, and a direct immunofluorescent-antibody test (DFA; MicroTrak; Syva Co., Palo Alto, Calif.) were used. C. trachomatis was detected in 54 specimens by at least one method. Forty-four, 44, and 37 specimens were positive by culture, probe, and DFA, respectively, and 31 were positive by all three methods. Considering culture-positive plus both probe- and DFA-positive results as the "gold standard," we determined the overall sensitivity, specificity, and positive and negative predictive values of the probe to be 80, 98, 82, and 98%, respectively. These values were 94, 98, 84, and 99%, respectively, in emergency room patients and 71, 98, 80, and 97%, respectively, in clinic patients. The sensitivities, specificities, and negative predictive values of the DFA and probe were comparable. The positive predictive values of the DFA in all patients and in emergency room and clinic patients were 97, 100, and 95%, respectively. Given the number of probe-positive results that were not confirmed by culture, we do not recommend using the Gen-Probe PACE to screen for C. trachomatis in women with a low to moderate risk for infection.

Preanesthetic medication in children: a comparison of oral transmucosal fentanyl citrate versus placebo

Initial studies have suggested that oral transmucosal fentanyl citrate (OTFC) in a dose of 15-20 micrograms/kg may be a safe and effective preanesthetic medication in children and adults, but this has not been demonstrated in a randomized, double-blind fashion. The purpose of this study was to determine in a randomized, double-blind manner, the efficacy of a lollipop containing fentanyl citrate as a preanesthetic medication before surgery in children. Forty health ASA physical status 1 or 2 children 3-12 yr of age were divided randomly and in double-blind fashion into two groups. Group 1 received the lollipop containing OTFC and group 2 received a placebo lollipop. An appropriate size lollipop was chosen so that if the patient received fentanyl, the total dose would be 15-20 micrograms/kg. Anxiety, sedation, and separation scores were assessed preoperatively and ease of induction was rated. Oxygen saturation and respiratory rate were monitored. Time intervals from preanesthetic to induction and from recovery room (PACU) admission to discharge were noted. Recovery room behavior was assessed upon admission and discharge. Complications and the need for postoperative opioids were noted. OTFC produced significantly more sedation and less anxiety compared with that following placebo. Respiratory rate was significantly decreased in the OTFC group, but oxygen saturation was not significantly different between groups. Anxiety and separation scores and the quality of induction were better in the OTFC group. There was a higher incidence of nausea and pruritus in the fentanyl group. OTFC did not prolong the PACU stay.

Retreatment of recurrent pelvic tumors with iodine-125

We describe our experience with successful retreatment of common pelvic tumors including recurrent cervical and endometrial cancer, colorectal cancer, and soft tissue sarcomas. Two different permanent interstitial 125iodine (125I) endocurietherapy (ECT) techniques were employed. The first technique, percutaneous transperineal template 125I ECT, was used in the retreatment of recurrent tumors located within the true pelvis. The second technique, implantation of 125I in Vicryl carrier following celiotomy, was used for retreatment of recurrent tumors located outside the true pelvis within the false pelvis.

Simultaneous measurements of cardiac output by thermodilution, esophageal doppler, and electrical impedance in anesthetized patients

Simultaneous intraoperative measurements of cardiac output were obtained in nine patients with transesophageal Doppler, transthoracic impedance, and pulmonary artery thermodilution techniques to evaluate the utility of the noninvasive methods. Pairs of noninvasive and thermodilution measurements were obtained 25 times with transesophageal Doppler and 58 times with transthoracic impedance. Correlation of the noninvasive measurements with thermodilution was poor, with r = 0.43 for transthoracic impedance and r = .68 for transesophageal Doppler. The average difference between the noninvasive and the thermodilution values was -0.4 +/- 1.4 L/min (mean +/- SD) and -0.1 +/- 1.6 L/min for impedance and Doppler, respectively. Changes in cardiac output at sequential time points as measured by thermodilution were predicted with 95% confidence only when a change of >4 L/min was observed by transesophageal Doppler or >8 L/min was observed by transthoracic impedance. Therefore, it is concluded that neither noninvasive technique reliably estimated cardiac output as determined by thermodilution, and neither tracked trends.

Decreased morbidity and increased survival in cervical cancer treatment

Thirty-seven patients with previously untreated invasive carcinoma of the uterine cervix, International Federation of Gynecology and Obstetrics (FIGO) stages IB to IVA, were treated with 4,000 rad external beam radiotherapy (EXRT) to midplane, followed by two intracavitary endocurietherapy (ECT) applications of 2,500 rad each to point "A" using a Kumar applicator, for a total dose of 9,000 rad. The major complication rate was 2.7 percent, and the local control rate was 85 percent (22/26 patients) for stages IB and II, and 91 percent (10/11 patients) for stages III and IVA. The three-year uncorrected observed actuarial survival was 80.3 percent for stages IB and II, and 81.8 percent for stages III and IVA. The three-year adjusted actuarial survival rate was 95.2 percent for stages IB and II, and 90.5 percent for stages III and IVA.

TAH and BSO with adjuvant pelvic EXRT and vaginal Cs-137 boost in the management of carcinoma of the endometrium

Combined surgery and radiation has become standard therapy for operable endometrial cancer patients with stage IA (grade 2-3 or deep muscle invasion), stage IB, stage II, and selected stage III disease. We discuss the rationale for whole pelvic external-beam radiation therapy (EXRT) followed by vaginal endocurietherapy (ECT) boost, and present the outcome of 43 patients with endometrial cancer treated by combined surgery and radiation.

Techniques for management of vulvar cancer by irradiation alone

Vulvar cancer has traditionally been managed surgically, rather than by means of irradiation, because of the poor tolerance of the vulvar skin and mucous membranes to X-ray treatment. The use of moderate dose (4,000 rad) external-beam radiotherapy (EXRT) combined with two interstitial 192iridium endocurietherapy (ECT) applications of 2,500 rad to 3,000 rad allows delivery of an adequate tumoricidal dose (9,000 rad to 10,000 rad total dose) without producing radiation vulvitis. Irradiation is an effective alternate means of treatment in elderly patients who are medically unfit for radical vulvectomy and lymphadenectomy. It also provides an alternative to surgery for those patients who desire preservation of the genitourinary anatomy.

Choice of afterloading endocurietherapy techniques for vaginal carcinoma

Vaginal cancer is highly curable in all stages by combining the proper interstitial or intracavitary endocurietherapy (ECT) techniques and external beam radiation therapy (EXRT). Each case must be individualized following careful evaluation of stage and local extent of disease. We describe three afterloading ECT techniques used for treatment of various presentations of vaginal cancer: 1) 137cesium vaginal obturator used for superficial lesions; 2) afterloading 192iridium tube and button technique used for localized lesions of the lower one-third of the vagina which do not involve more than one-half of the circumference; and 3) afterloading transperineal interstitial 192iridium template technique used for thick invasive lesions of the upper two-thirds of the vagina. Our technique for EXRT is also described.

Low morbidity following 9,000-rad intracavitary endocurietherapy (ECT) using the Kumar Cervical Applicator and external-beam radiotherapy (EXRT) in the management of carcinoma of the uterine cervix

The Kumar Cervical Applicator minimizes patient discomfort and improves patient mobility while reducing the tendency of the applicator to rotate during the 40 to 50 hours of uterine intracavitary endocurietherapy. Patients with previously untreated invasive carcinoma of the uterine cervix, F.I.G.O. stages IB-IVA, were treated with two Kumar intracavitary endocurietherapy (ECT) applications of 2,500 rad each to point "A," and 4,000 rad external-beam radiotherapy (EXRT) to midplane, for a total dose of 9,000 rad. The major complication rate was 2.7%, and the local control rate was 85% (22/26 patients) for stage I and II, and 91% (10/11 patients) for stage III and IVA.

Testing computer-controlled infusion pumps by simulation

The pharmacokinetic behavior of intravenous anesthetic drugs can be described by two- or three-compartment models. Rapid achievement and maintenance of steady plasma concentrations of these drugs requires a complicated delivery scheme, perhaps best controlled by a computer. The authors developed a method of simulating the performance of a computer-controlled infusion pump from the differential equations describing drug transfer between compartments. They also derived a mathematically simple and flexible approximate solution to these equations using Euler's numerical method. They incorporated this approximate solution into a computer-controlled infusion pump for intravenous drugs. They tested their pump by simulating the administration of fentanyl to a hypothetical patient whose fentanyl pharmacokinetics were described by a three-compartment model. The exact analytical solution served as the standard of comparison. The approximation technique, using a 15-s interval between model updates, had a maximum error of 0.35 ng.ml-1, and rapidly converged on the exact solution. The simulations revealed oscillations in the system. The authors suggest that such simulations be used to evaluate computer-controlled infusion pumps prior to clinical trials of these devices.

Studies in REST. I. Reduced Environmental Stimulation Therapy (REST) and reduced alcohol consumption

Reduced Environmental Stimulation Therapy (REST), formerly known as "sensory deprivation," was used in conjunction with pre-recorded anti-alcohol messages to reduce alcohol consumption. Subjects were college students of both sexes who were "heavy social drinkers," that is, early prodromal alcoholics. There were two studies. In the pilot study experimental subjects had two and a half hours of REST, during which they heard one of two differently worded anti-alcohol messages. After two weeks their alcohol intake dropped significantly from baseline levels (33% and 29%); control subjects showed no significant changes. In a replication and follow-up study experimental subjects had two and a half hours of REST, during which they heard a revised version of the most effective anti-alcohol message used in the pilot study. Two weeks later their alcohol consumption dropped 55% from baseline levels. These reductions in alcohol intake were fully sustained on follow-up three months and six months later. Untreated control subjects showed increased alcohol intake on follow-up.

Betamethasone dipropionate in optimized vehicle. Intermittent pulse dosing for extended maintenance treatment of psoriasis

A study was done of extended maintenance therapy using either betamethasone dipropionate (Diprolene) in optimized vehicle (OV) (ointment) or placebo in patients with psoriasis vulgaris. Of 59 patients originally enrolled in the study, 38 assessable patients achieved clearing of at least 85% improvement from baseline with traditional betamethasone in OV twice a day for two to three weeks before intermittent pulse dosing was attempted. Thereafter, the test medication was used on weekends (three consecutive doses at 12-hour intervals) once a week. Fourteen patients (74%) of the betamethasone in OV group and four patients (21%) of the placebo group maintained a remission status for 12 weeks. Intermittent pulse dosing with betamethasone in OV seems safe and efficacious maintenance therapy in selected psoriatic patients.

HPLC method for the analysis of cyproterone acetate in tablets

A reversed-phase high-performance liquid chromatographic (HPLC) method is described for the analysis of cyproterone acetate in tablets. This steroid is extracted and quantitated using a C18 column. This procedure is shown to be rapid, simple, and valid in terms of recovery, linearity, and precision. Application of this method to analyze dilute samples obtained from dissolution testing is demonstrated.

Assay methods for fentanyl in serum: gas-liquid chromatography versus radioimmunoassay

In this study, two independent laboratories assessed the validity of the fentanyl radioimmunoassay (RIA) by measuring a series of spiked control serum samples and 429 serum samples from 20 patients receiving fentanyl for their anesthesia. Additionally, a gas-liquid chromatographic (GLC) method specific for the parent drug was also applied to the same serum samples. The RIA measurement of fentanyl by the two laboratories resulted in comparable values for both control samples and samples from patients in a range of 0.5-50 ng/ml. The GLC method agreed with both RIA measurements in the spiked control and patient samples. The authors' results demonstrate the validity of the RIA as a measurement technique for fentanyl in human serum samples.

Improved radioreceptor assay of opiate narcotics in human serum: application to fentanyl and morphine metabolism

A recently developed radioreceptor assay (RRA) (1) that employs 3H-naloxone and rat brain membrane homogenates was improved two ways. First, the brain membranes were preincubated in the presence of sodium ions, and second, manganase-II ions were added to the sample incubations. These changes enhanced the assay sensitivity and reproducibility with stored membrane preparations and reduced the effects of serum constituents (Na+) on ligand-receptor binding. Patient sera were assayed by radioimmunoassay (RIA) and RRA after fentanyl administration and by high-performance liquid chromatography (HPLC) and RRA after morphine administration. The results with both fentanyl assays were comparable, and no fentanyl metabolites were detectable by RRA after HPLC of serum extracts. In contrast, preliminary results with the HPLC-RRA procedure suggest the presence of an active morphine metabolite of unknown structure in sera obtained from patients on morphine therapy.