A Low Percentage of Patients Satisfy Typical Indications for Single-stage Exchange Arthroplasty for Chronic Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) is a leading cause of revision arthroplasty. Considerable controversy still exists whether single- or two-stage exchange is the better approach for patients with chronic PJI. Historically, single-stage exchange arthroplasty was thought to have an unacceptably high risk of reinfection compared with two-stage exchange but recent studies have demonstrated that this may not be the case. To be considered for single-stage exchange, patients should meet certain criteria including a preoperatively identified nonvirulent pathogen in an immunocompetent host with an uncompromised soft tissue envelope. It is unclear what proportion of patients with chronic PJI actually meet these criteria. Additionally, patients who meet the criteria for single-stage exchange are selected because, in principle, they may be more likely to be able to overcome the infection, but it is unknown what the reinfection risk is in patients undergoing two-stage exchange who might have met selection criteria for single-stage exchange. QUESTIONS/PURPOSES: (1) What percentage of patients with chronic PJI treated at our institution met the International Consensus Meeting criteria for single-stage exchange arthroplasty? (2) Is the risk of persistent or recurrent infection lower for patients treated with two-stage exchange who met International Consensus Meeting criteria for single-stage exchange than it is among those who did not meet those inclusion criteria? METHODS: Between 2012 and 2016, one referral center treated 120 patients with chronic PJI as determined by Musculoskeletal Infection Society (MSIS) criteria. During this time, we used single-stage exchange only rarely in patients with chronic PJI (3%; four of 120), and only in oncologic patients with mega-prosthesis implants; 7% (eight of 120) underwent other procedures (resection arthroplasty or arthrodesis). Of the remaining 108, 16% (17) were lost to follow-up; the remaining 91 were evaluated in this retrospective study. To answer our first question, we applied the International Consensus Meeting indications for single-stage exchange, which were a known nonvirulent preoperative organism, an immunocompetent host, and a healthy soft-tissue envelope without a sinus tract; we then calculated the percentage of patients who would have met those criteria. To answer our second question, we compared those who would and would not have met those criteria in terms of the proportion who were determined to be infection-free at 2 years using the MSIS criteria. RESULTS: Only 19% (20 of 108) of patients met the International Consensus Meeting criteria for single-stage exchange. With the numbers available, there was no difference between those who met and did not meet those criteria in terms of the proportion of patients who had persistent or recurrent infection 2 years after treatment (three of 15 versus 32% [24 of 76]; p = 0.38). CONCLUSIONS: We found that only a small proportion of patients who presented with chronic PJI to a referral center would have been suitable for single-stage direct exchange; with the numbers available, we found no difference in the reinfection risk after two-stage revision in those patients compared with those who would not have met those criteria. Consequently, it is possible that a small proportion of patients may benefit from single-stage exchange, but our small sample size may have missed important differences in reinfection risk, and so our findings on that question must be considered preliminary. Larger studies randomizing patients who meet single-stage criteria to either single- or two-stage exchange will better elucidate the true reinfection risk in this patient population. LEVEL OF EVIDENCE: Level III, therapeutic study.

Preterm prediction study: comparison of the cervical score and Bishop score for prediction of spontaneous preterm delivery.

OBJECTIVE: To prospectively compare digital cervical score with Bishop score as a predictor of spontaneous preterm delivery before 35 weeks of gestation. METHODS: Data from a cohort of 2,916 singleton pregnancies enrolled in a multicenter preterm prediction study were available. Patients underwent digital cervical examinations at 22-24 and 26-29 weeks of gestation for calculation of Bishop score and cervical score. Relationships between Bishop score, cervical score, and spontaneous preterm delivery were assessed with multivariable logistic regression analysis, McNemar test, and receiver operating characteristic (ROC) curves to identify appropriate diagnostic thresholds and predictive capability. RESULTS: One hundred twenty-seven of 2,916 patients (4.4%) undergoing cervical examination at 22-24 weeks had a spontaneous preterm delivery before 35 weeks. Eighty-four of the 2,538 (3.3%) reexamined at 26-29 weeks also had spontaneous preterm delivery. Receiver operating characteristic curves indicated that optimal diagnostic thresholds for Bishop score were at least 4 at 22-24 weeks, at least 5 at 26-29 weeks, and less than 1.5 at both examinations for cervical score. At 22-24 weeks, areas under the ROC curve favored Bishop score. At 26-29 weeks, there was no significant difference in areas under the ROC curve; however, a cervical score less than 1.5 (sensitivity 35.7%, false positive rate 4.8%) was superior to a Bishop score of 5 or more (P<.001). CONCLUSION: Both cervical evaluations are associated with spontaneous preterm delivery in a singleton population; however, predictive capabilities for spontaneous preterm delivery were modest among women with low event prevalence. Although Bishop score performed better in the mid trimester, by 26-29 weeks a cervical score less than 1.5 was a better predictor of spontaneous preterm delivery before 35 weeks than a Bishop score of at least 5.

[What do prostate cancer patients know about smoking? : Results of a bicentric questionnaire study (KRAUT study)]. / Was wissen Patienten mit einem Prostatakarzinom über das Rauchen? : Ergebnisse einer bizentrischen Fragebogenstudie (KRAUT-Studie).

BACKGROUND: According to the results of a recent meta-analysis, cancer-specific mortality of prostate cancer (PCA) patients is enhanced by 24 % in case of a positive smoking history with a dose-dependent impact of smoking. Until now it is unknown whether this information actually reaches the patients and how extensively an informational discussion about this topic is pursued by physicians. OBJECTIVE: Three study hypotheses were defined: (1) the knowledge of PCA patients about the potential relationship between tumor progression and cigarette consumption is low, (2) only in rare cases has a clear statement been provided by treating physicians including the explicit advice to stop smoking, and (3) there was a direct association between tumor stage and the extent of cigarette consumption. MATERIALS AND METHODS: A questionnaire comprising 23 items was developed and validated with 25 uro-oncological patients prior to study start. Between September 2013 and December 2014 a total of 124 PCA patients (median age 65 years) from two urology departments were included in this questionnaire-based survey. RESULTS: The study population comprised 43 % (n = 54), 39 % (n = 48), and 18 % (n = 22) nonsmokers, former smokers and active smokers, respectively. Active and former smokers differed insignificantly in the number of pack-years only (24.8 vs. 23.7 years, p = 0.995). Of the patients, 56 % regarded an influence of cigarette consumption on the PCA-specific prognosis as possible. However, because a significant (p < 0.001) number of patients wrongly suspected smoking to be causative for PCA development, their knowledge about PCA prognosis is supposedly not based on adequate knowledge. Two of 22 active smokers (9.1 %), 5 of 48 former smokers (10.4 %), and 2 of 54 nonsmokers (3.7 %) had an informational discussion with their urologist about the association of cigarette consumption and PCA-related prognosis (a further 9.1, 4.2 and 3.7 %, respectively, received this information solely from other medical specialties). Only 1 of 22 active smokers (4.5 %) was offered medical aids for smoking cessation by the general practitioner; none of the patients received such support by an urologist. There was no association between a positive smoking history or number of pack-years and PCA tumor stage. CONCLUSIONS: Education of PCA patients about the relationship between cigarette consumption and cancer-related prognosis is currently inadequate. Following the latest findings on this topic, urologists should pursue informational discussions with their patients, thereby strengthening their position as the primary contact person for decision making in PCA management.

Financial compensation for radiotherapy-related adverse events in a judicial system where proof of medical negligence is not required.

PURPOSE: To examine the frequency of adverse events related to radiation therapy that lead to financial compensation in a judicial system that is not based on litigation in court but on statutory insurance where proof of medical negligence is not required for obtaining compensation. METHODS AND MATERIALS: In Finland, an injured patient does not sue through the courts, but submits an insurance claim to the Patient Insurance Association. Proof of medical negligence is not required for obtaining compensation. We reviewed all filed claims associated with radiotherapy presented to the Patient Insurance Association from May 1987 to January 1999. During this time period, 1,732,000 patient visits to radiation therapy units were made, and the estimated number of radiotherapy treatments was 86,600. The data collected included descriptions of the adverse events, examination of the radiation therapy procedures followed, assessment of the causal relation of the event to radiotherapy by the therapists involved and by independent reviewers, and the sums used for compensation. RESULTS: Only 102 patients (about 0.1%) had filed a claim for financial compensation, and in 18 (0.02%) cases the claim led to compensation. The mean national annual expenditure used for compensation was $35,200, and the sums paid in single cases ranged from $310 to $287,430 (median, $1,970). The expenditure used for compensating adverse radiation events was about $4 per treated patient, which is about 0.3% of all radiation therapy costs. CONCLUSIONS: The frequency of radiation therapy injuries that are financially compensated can remain low in an insurance-based judicial system where no litigation or attorneys are involved.

An interdisciplinary approach to the assessment and behavioral treatment of urinary incontinence in geriatric outpatients.

OBJECTIVE: To test the effectiveness of an interdisciplinary assessment and behavioral treatment of persistent urinary incontinence in geriatric outpatients. DESIGN: Prospective case series in which frequency of incontinence was measured before and after intervention. SETTING: We established an interdisciplinary continence program within an existing academic center, the Benedum Geriatric Center. PATIENTS: Convenience sample of 70 non-demented outpatients aged 56 to 90 years. Behavioral treatment was provided to 29 patients including many with multiple medical problems (Mean = 6.0 problems). INTERVENTION: Behavioral treatment consisted of biofeedback, pelvic floor muscle exercise, scheduled voiding, and other strategies for preventing accidental urine loss. OUTCOME MEASURE: Outcome of treatment was measured by comparing bladder diaries completed in the 2 weeks immediately following treatment to those completed in the pretreatment phase. RESULTS: Following an average 5.6 treatment sessions, the mean weekly frequency of accidents was reduced from 16.9 to 2.5 (P less than 0.01). Individual reductions ranged from 30.8% to 100% with an average of 81.6% improvement. Ten patients achieved continence. Patients with mixed incontinence had greater improvement than those with urge incontinence alone (P less than 0.05), and patients who reported previous evaluation or treatment had a poorer outcome than those coming for their first evaluation (P = 0.05). Degree of improvement was not significantly related to age, duration of symptoms, baseline frequency of accidents, number of treatment sessions, number of other medical diagnoses, or urodynamic findings. CONCLUSION: We conclude that older adults who are able and willing to participate in behavioral treatment can benefit significantly despite other health problems or disabilities.

Birth weight-length ratios, ponderal indexes, placental weights, and birth weight-placenta ratios in a large population.

BACKGROUND: Birth weight (BW)/length ratios, ponderal indexes, placental weights, and BW/placental weight ratios have been correlated with perinatal morbidity and mortality. METHODS: Cross-sectional survey of live-born, structurally normal, singleton neonates delivered at a tertiary care center in Detroit, Mich, from 1984 through 1991. Subjects were included if dating based on menstrual dates and ultrasonographic estimations agreed with Ballard examination to within 2 weeks. RESULTS: Of 33,138 neonates, 26,983 (81.4%) were black. While all indexes significantly increased with advancing gestational age, only placental weights (without prior draining of blood, blotting the placenta dry, or trimming the membranes or cord) and BW/length ratios significantly increased beyond 40 weeks' gestation. Multivariate analysis of variance revealed that placental weights, BW/placenta ratios, and BW/length ratios were significantly related to gender and ethnicity, but ponderal index was not. Placental weights were larger, and BW/placenta ratios were smaller than studies that trimmed the placentas before weighing. CONCLUSIONS: All indexes were gestational age dependent, but ponderal index and BW/placenta ratios do not increase beyond 40 weeks' gestation. Except for ponderal index, interpretation of these indexes should be specific for ethnicity, gender, and manner of placental preparation.

The cost-effectiveness of routine type and screen admission testing for expected vaginal delivery.

OBJECTIVE: To evaluate the cost effectiveness of routine admission type and screen testing for expected vaginal delivery. METHODS: A retrospective review was conducted in patients transfused with blood during an admission that anticipated a vaginal delivery over a 3-year period, at Hutzel Hospital, in Detroit, Michigan. RESULTS: Of 16,291 patients admitted for an expectant vaginal delivery, 76 (.47%) (95% confidence interval [CI] .37%, .58%) required blood transfusion during the time of their admission. Medical records of these 76 patients were evaluated as to urgency and risk factors. Most of the blood transfusions were related to previously identified risk factors, including previous postpartum hemorrhage, multiple pregnancies, previous cesarean delivery, abruptio placentae, and admission anemia. Four patients received an urgent blood transfusion without a previously identifiable risk factor. We found an overall urgent blood transfusion rate without admission risk factors to be 2.5 per 10,000 vaginal deliveries (95% CI .9 per 10,000, 6.3 per 10,000) CONCLUSION: Routine admission type and screen testing for an expected normal vaginal delivery does not seem to enhance patient care and should be eliminated for patients without substantial risk factors. In the rare event that a patient without a previously identified risk factor required an urgent blood transfusion, O negative blood could be given in the interim pending formal type and cross match.

Sickle cell E hemoglobinopathy and pregnancy.

The incidence of E hemoglobinopathies has been increasing in the United States. This is the first known case report of hemoglobin S/E in pregnancy. Management was based on the similarities of the S/E and S/beta-thalassemia hemoglobinopathies, and included partial exchange transfusion. Complications included fetal distress, congenital hydrocephalus, and cleft lip and palate. It appears that S/E and E/beta-thalassemia hemoglobinopathies may entail increased perinatal risks, but that favorable pregnancy outcomes may be anticipated with homozygous hemoglobin E or hemoglobin E trait.

Cocaine abuse is associated with abruptio placentae and decreased birth weight, but not shorter labor.

Many of our patients report having ingested cocaine hoping to decrease the duration of labor. We reviewed the computerized records of 592 women who abused cocaine. Compared with 4687 controls, women who ingested cocaine were older and had higher parity. Birth weight, birth weight percentile, and gestational age at delivery were significantly decreased among their neonates, and the incidence of abruptio placentae was nearly doubled among these women. Although these factors tend to shorten labor, the total duration of labor was not significantly different between the two groups. These data add to the accumulating evidence that cocaine abuse is associated with increased obstetric morbidity, but do not support the belief that cocaine shortens labor.

Modified stylet technique for tenting of amniotic membranes.

A modified amniocentesis technique can reduce the failure rate in cases of tenting of the membranes. Failure to aspirate amniotic fluid (AF) because of amniotic membrane tenting may persist after advancement and rotation of the needle. In such cases, the membranes may be pierced by using a stylet that is longer than the length of the needle. With the needle in the middle of a suitable AF pocket, the stylet of the needle is replaced with a longer stylet. Under real-time ultrasonographic guidance, the tip of the stylet is then rapidly advanced 5-10 mm beyond the tip of the needle. During genetic amniocentesis, we have used the longer stylet technique to pierce tented membranes without complications in 21 of 22 cases.

Skeletal muscle response to spaceflight, whole body suspension, and recovery in rats.

Comparisons of soleus and extensor digitorum longus (EDL) muscles from male Sprague-Dawley rats (350-400 g) after 7 days of weightlessness, 7 and 14 days of whole body suspension (WBS), and 7 days of recovery from WBS and from vivarium controls were made. Muscle mass loss of approximately 30% was observed in soleus after 7 and 14 days of WBS. Measurement of slow- and fast-twitch fibers showed significant alterations. Reductions in cross-sectional areas and increases in fiber densities in soleus after spaceflight and WBS were related to previous findings of muscle atrophy during unloading. Capillary density also showed a marked increase with unloading. Seven days of weightlessness were sufficient to effect a 20 and 15% loss in absolute muscle mass in soleus and EDL, respectively. However, the antigravity soleus was more responsive in terms of cross-sectional area reductions. After 7 days of recovery from WBS, with normal ambulatory loading, the parameters studied showed a reversal to control levels. Muscle plasticity, in terms of fiber and capillary responses, indicated differences in responses in the two types of muscles and further amplified that antigravity posture muscles are highly susceptible to unloading. Studies of recovery from spaceflight for both muscle metabolism and microvascular modifications are further justified.

Fetal hemorrhage from umbilical cord hemangioma.

Hemangiomas of the umbilical cord are rare. In this case, an acute, massive fetal hemorrhage from a ruptured umbilical hemangioma occurred after spontaneous rupture of membranes. Ectopic small intestinal mucosa covered the proximal surface of the umbilical cord. Fetal anomalies included a patent vitellointestinal duct remnant and distal ileal atresia. Fetal hemorrhage appears to be another previously unreported and potentially life-threatening complication of umbilical hemangiomas.

Decrease in myometrial beta-adrenergic receptors with prenatal cocaine use.

OBJECTIVE: To determine if cocaine use during pregnancy is associated with a reduction in the number or affinity of beta-adrenergic receptors in human myometrium. METHODS: Myometrium was obtained at cesarean delivery of five women who reported using cocaine during pregnancy and from ten controls. Saturation binding assays were performed on the myometrial membrane fractions using [125I]-cyanopindolol to determine beta-adrenergic receptor concentration and affinity. The percentages of beta 1- and beta 2-adrenergic receptors were determined in three cocaine users and four control patients by performing competition binding assays using the beta 2 antagonist ICI 118,551. Results were compared using unpaired Student t tests. RESULTS: Women who reported using cocaine during pregnancy had a significantly lower mean (+/- standard deviation) concentration of myometrial beta-adrenergic receptors than did controls (22 +/- 8 versus 52 +/- 23 fmol/mg protein, respectively). There was no difference in the receptor affinity constants between cocaine users and controls (16 +/- 2 pmol/L for both groups). The percentages of beta 1- and beta 2-adrenergic receptors in the myometrium of the cocaine-use group and control group were similar: 86 +/- 1% beta 2 in the cocaine-use group and 83 +/- 7% beta 2 in the control group. CONCLUSION: Cocaine use during pregnancy may be associated with a down-regulation of beta-adrenergic receptors in human myometrium. This could result in a decreased capacity for uterine relaxation and, consequently, a predisposition to preterm labor.

Characterization of the effect of cocaine on catecholamine uptake by pregnant myometrium.

OBJECTIVE: To characterize the effect of cocaine on catecholamine uptake by myometrium from pregnant women. METHODS: Slices of myometrium obtained from nine women during elective cesarean delivery at term were incubated with [3H]-norepinephrine and various uptake inhibitors for 30 minutes. The radiolabeled material was extracted with perchloric acid, expressed as percent control (+/- standard error of the mean), and compared by one-factor analysis of variance and Fisher multiple range test. RESULTS: Myometrial uptake was inhibited by cocaine (42 +/- 9%) by neuronal (type 1) uptake inhibitors (desipramine 41 +/- 14%; N-ethylmaleimide 53 +/- 8%), and by extraneuronal (type 2) inhibitors (normetanephrine 56 +/- 19%; corticosterone 73 +/- 9%). When uptake inhibitors were used in combination with cocaine, uptake was not decreased further in the presence of neuronal inhibitors (desipramine plus cocaine 40 +/- 20%; N-ethylmaleimide plus cocaine 42 +/- 4%). However, the effect of cocaine appeared to be added to that of extraneuronal inhibitors (normetanephrine plus cocaine 25 +/- 14%; corticosterone plus cocaine 32 +/- 1%). CONCLUSION: Catecholamine uptake by myometrium in pregnant women appears to be both extraneuronal and neuronal in nature, and cocaine inhibits the neuronal portion of this uptake. This mechanism may play a role in the increased rate of premature delivery associated with cocaine abuse.

Intravenous therapy of metronidazole-resistant Trichomonas vaginalis.

Metronidazole resistance is an uncommon cause of treatment failure of Trichomonas vaginalis. High-dose intravenous metronidazole was used successfully to treat a patient in whom repeated oral therapy with this agent had failed. Metronidazole resistance was documented by aerobic cultures for susceptibility; anaerobic cultures failed to indicate resistance. Metronidazole serum levels were documented. With failure of repeated oral therapy, intravenous metronidazole may be indicated if there is no evidence of other causes for treatment failure, such as patient noncompliance or reinfection.

Amniotic fluid lamellar body count: cost-effective screening for fetal lung maturity.

OBJECTIVE: To create a highly specific cascade testing scheme for fetal lung maturity using the lamellar body count, lecithin/sphingomyelin ratio (L/S), and phosphatidylglycerol. METHODS: A nondedicated hematology analyzer (Sysmex NE 1500, Toa Medical Electronics, Los Angeles, CA) was used to determine the lamellar body counts of 209 unspun amniotic fluid specimens. Maximally specific lamellar body count cutoffs for biochemical maturity and immaturity were determined using receiver operating characteristic curves. Biochemical lung maturity was defined as either a mature L/S ratio or phosphatidylglycerol. Biochemical lung immaturity was defined as both an immature L/S ratio and an immature phosphatidylglycerol. RESULTS: A lamellar body count of less than 8000 (n = 17) was 100% specific for biochemical lung immaturity (positive predictive value = 100%, negative predictive value = 86%). A lamellar body count of greater than 32,000 was 98% specific for biochemical lung maturity (positive predictive value = 99%, negative predictive value = 63%). CONCLUSION: Testing only specimens where the lamellar body count was greater than 8000 and less than or equal to 32,000 for the L/S ratio and phosphatidylglycerol would preclude the need for 76% of all L/S and phosphatidylglycerol assays. Because the lamellar body count is quick, simple, and universally available, it could serve as an extremely cost-effective screening test for fetal lung maturity.

Fetal hemoglobin quantitations using the Hemocue system are rapid and accurate.

OBJECTIVES: To determine whether hemoglobin quantitations using the Hemocue system, a rapid and portable hemoglobin photometer, on fetal blood obtained via funipuncture were accurate compared to the Coulter S-Plus IV. We also examined whether gestational age or extremes in hemoglobin levels significantly affected the accuracy of the Hemocue system. METHODS: We performed fetal hemoglobin quantitations using both systems on 58 specimens obtained between 18-38 weeks' gestation. Correlation between values by both systems was determined by linear regression analysis. The effects of gestational age and hemoglobin extremes on the accuracy of the Hemocue system were evaluated by stepwise regression. RESULTS: The mean Hemocue value was 12.0 +/- 2.4 g/dL (range 3.3-16.4); the mean Coulter value was 11.7 +/- 2.3 g/dL (range 3.6-16.2). The regression equation for Hemocue (y) versus Coulter (x) values was y = 0.72 + 0.97x; r = 0.94 (P < .0001). Neither gestational age nor hemoglobin extremes significantly affected the accuracy of the Hemocue system. CONCLUSION: The Hemocue system is rapid and accurate for fetal hemoglobin quantitation between 18-38 weeks' gestation regardless of extremes in gestational age or hemoglobin levels.

Skeletal muscle atrophy in response to 14 days of weightlessness: vastus medialis.

The vastus medialis (VM) from rats after 14 days of microgravity on COSMOS 2044 (F) was compared with VM from tail-suspended hindlimb-unloaded rats (T) and ground controls, including vivarium (V), synchronous (S), and basal (B) animals. The VM is composed chiefly of fast-twitch fibers; however, it contains a deep portion closer to the bone with mixed slow- and fast-twitch fibers. In the mixed-fiber portion, type I and II fiber areas were significantly reduced in F animals. In the homogeneous portion with chiefly fast-twitch fibers, F rats also showed reductions in cross-sectional areas compared with T, V, and B but not S rats. Fiber densities (fibers/mm2) were greatest in VM from F rats. Capillary density changes paralleled fiber density changes. F animals have significantly greater density of capillaries in the mixed-fiber portion. Concentrations of protein, RNA, and DNA were highest in V controls, whereas F rats had the lowest level of total RNA. Lactate dehydrogenase activity, one measure of anaerobic capacity, was greater in F than in S rats. Citrate synthase activity, a measure of oxidative capacity, showed no significant differences between groups. Although triglyceride stores of VM were greater in F than in T rats, there were no significant differences from any of the control groups. It was concluded that VM wet weights may be a less sensitive measure of atrophy than the fiber area measurements. Fiber area decreases and fiber density increases in F animals were quantitatively comparable to those in soleus and extensor digitorum longus after 7 days of weightless flight in Spacelab 3. Our results suggest that VM shows measurable responses to weightlessness.

Hormonal contraception and platelet function.

PIP: 73 healthy women (29 controls, 25 using OCs, and 19 using Norplant) were selected from the clinic population at North Oakland Medical Center for inclusion in this study after obtaining informed consent. Age, race, height, weight, blood pressure, and cigarette smoking were recorded for each subject. 12 patients were on monophasic OCs while 13 were on triphasic preparations. Both hormonal contraceptive groups had used their particular contraceptive for at least 3 months prior to blood drawing. Platelet tests were performed within 2 hours of sample collection: platelet counts (PLC) and mean platelet volume (MPV) were determined on an Automated Platelet Counter (Baker 810 Platelet Analyzer). Whole blood aggregation was performed on a platelet aggregometer (Chrono-Log, Model 550) using both ADP (ADP, 5 mM) and collagen (COLL, 2 mcg/ml) as inducing agents. Demographic differences were not significant (p 0.05) among the 3 treatment groups, whose average age was 25.3-25.8 years old. Furthermore, no significant differences (p 0.05) in platelet function were detected among controls or subjects receiving either oral contraceptives or Norplant, compared to control patients. The mean platelet counts (X 10/9/L) were 223 for OC users, 231 for Norplant users, and 232 for controls. The respective platelet aggregation (ADP, ohms) values were 12.5, 18.0, and 19.2 as well as (COLL, ohms) 35.6, 40.7, and 39.0. These results demonstrated that there is no evidence for altered platelet function, with the testing methods employed, in women using either Norplant or combination low dose oral contraceptives. To date, several studies have examined this issue, with contradictory reports about the effects of hormonal contraceptives in platelet function. After controlling for differences between various steroid preparations and other such confounding variables, some of these conflicting conclusions could be the result of a lack of uniformity among the methods used to evaluate platelet aggregation. The ability to draw conclusions regarding altered in vivo thrombotic potential from these studies is thus questionable.^ieng