Prilocaine in arthroscopy: clinical pharmacokinetics and rational use.

Prilocaine pharmacokinetics were determined in 60 patients receiving the drug by two different routes of administration (intra-articular and subcutaneous) during arthroscopy under local anesthesia with controlled pressure irrigation. Resorption of prilocaine by subcutaneous tissues was slow and did not lead to high serum levels. On the contrary, prilocaine resorption by the synovium was fast and induced a sharp serum peak (265.8 +/- 163.5 ng/ml) in the hour after the end of the examination. The drug was completely eliminated from the blood after 24 hours, as the prilocaine t1/2 is about 5 hours. The first procedure was perfected to reduce the risk of methemoglobinemia, which occurred in four of 105 patients. Applied pressure was lowered to 100 mm Hg to prevent the escape of anesthetic solution into the soft tissue of the leg, the prilocaine concentration was reduced to 1 gm/L, and the arthroscope was only set up after a delay to allow the intra-articular anesthetic effect of prilocaine to become established. So far, 200 arthroscopies have been performed with this improved protocol without any problem.

[Echo-Doppler for early diagnosis of deep venous thrombosis in orthopedic surgery and traumatology. A retrospective study of 1,647 patients]. / Echo-Doppler pour le diagnostic précoce des thromboses veineuses profondes en chirurgie orthopédique et traumatologique. A propos de 1,647 malades explorés.

UNLABELLED: The authors report the results of duplex ultrasound scanning investigation for the detection of deep venous thrombosis after orthopedic surgery and compare asymptomatic and symptomatic populations. PURPOSE OF THE STUDY: To estimate the rate of deep venous thrombosis diagnosed by duplex scanning in those 2 populations and precise their features. MATERIAL: A total of 1,647 in-patients all receiving low-molecular-weight heparin and investigated from 1989 to 1993. either for screening because of high risk of thrombosis (asymptomatic group: 930 patients, mean age +/- SD 63 +/- 17 years) or for clinical suspicion of deep vein thrombosis (symptomatic group; 717 patients, mean age +/- SD: 57 +/- 21 years). Difference between the two groups mean ages were significant (p < 10(-8). METHODS: An Hitachi EUB 450 duplex and an Acuson colour duplex 128 XP, with 3.5 MHz and 7.5 MHz linear probes were used. Veins were tested for compressibility in transverse view from caval site to both ankles. Retrospective analysis of patients database results has been achieved. RESULTS: There was no significant difference in deep vein thrombosis rate between screening asymptomatic group (356/930:38%) and symptomatic group (253/717: 35%). There was a linear relation, in the 2 groups, between age and deep vein thrombosis rate, from 10% before twenty to 45% after eighty years old. For a relative risk to have thrombosis detected before twenty definite at 1, it was 2.1 for 20-29, 4.9 for 40-49, 6.2 for 60-69 and 8.6 later than 80 years old. Proximal deep vein thrombosis was detected in only 5% (87/1,647) of patients. Distal muscular soleal veins were the most usual involved sites of thrombosis. Isolated soleal thrombosis were detected in 16% (270/1,647) of patients. There was non significant difference between the deep vein thrombosis rate after total knee or hip arthroplasty among selected patients for duplex scanning from 1989, and the true prevalence assessed among all the patients who have undergone total hip or knee arthroplaty during the last 6 months. DISCUSSION: Pessimistic results previously reported for duplex screening among asymptomatic patients are not confirmed. Calf vein thrombosis rate assessed by duplex scanning exceeds by 15 a 20% usual rates assessed by contrast venography, among patients receiving low-molecular-weight heparins. That difference could be assigned to the isolated muscular soleal thrombosis usually missed at contrast venography. CONCLUSION: Deep vein thrombosis rate among orthopedic surgical patients, is much higher when detected with Duplex ultrasound scanning than detected with contrast venography, and is related to patient age. Screening for deep venous thrombosis by duplex scanning in orthopedic surgery is as efficient among asymptomatic as among symptomatic patients and could become soon a systematic screening. Soleal vein thrombosis are the most usual. Mechanical calf venous pump stimulation in association with low molecular weight heparin, has to be evaluated in attempting to reduce those muscular soleal veins thrombosis.

[Efficacy and tolerance of Elohes 6% during peroperative normovolemic dilution]. / Efficacité et tolérance de l'Elohes 6% au cours de l'hémodilution normovolémique peropératoire.

This study assessed the cardiovascular stability of intraoperative normovolaemic haemodilution carried out with 6% Elohes during the exchange, the intraoperative, recovery and postoperative periods, as well as its effects on coagulation and renal function. Ten patients, ranked ASA 1, were included. Patients were premedicated with 100 mg of hydroxyzine, and anaesthesia was induced with 2 mg.kg-1 propofol, 3 micrograms.kg-1 fentanyl, and 0.5 mg.kg-1 atracurium. Maintenance was obtained with propofol, fentanyl and 50% nitrous oxide in oxygen. Haemodilution, carried out with a peripheral venous catheter, size 14 G, consisted in the removal of 15 ml.kg-1 of blood and its simultaneous replacement with Elohes 6%. Heart rate, systolic, diastolic and mean blood pressures were recorded before anaesthetic induction, every 5 min during the haemodilution, and thereafter during surgery, recovery and postoperative periods, up to the third postoperative day. Blood haemoglobin, fibrinogen, prothrombin, sodium, potassium, urea and creatinine concentrations, haematocrit, platelet count, and bleeding and activated cephalin times were assessed before and immediately after haemodilution, and on postoperative days 1 and 3. A mean of 1,295 +/- 68 ml of blood were removed during a 32 +/- 2 min period, and replaced by 1,315 +/- 64 ml of Elohes. Haematocrit decreased from 44 +/- 1.1% to 29.7 +/- 0.8%. There were no significant alterations in other parameters, except for an increase in heart rate at the time of extubation. Cardiovascular parameters, as well as the haemodilution, were stable up to the end of the study period. It is concluded that replacing blood with Elohes for intentional haemodilution affords convenient cardiovascular stability.(ABSTRACT TRUNCATED AT 250 WORDS)

[Normovolemic hemodilution in the prevention of venous thrombosis in orthopedic and traumatologic surgery]. / L'hémodilution normovolémique dans la prévention des thromboses veineuses en chirurgie orthopédique et traumatologique.

In 114 patients undergoing major orthopedic surgery among which 47 hip replacements, hematocrit was reduced to between 30 and 32% by withdrawing red cells without increasing the blood volume. Deep veinous thrombosis was observed in 4 cases. No pulmonary embolism occurred. Incisional hematoma was noted in 0.9% of the cases.

Contraceptive pills and thrombosis: effects of the French crisis on prescriptions and consequences for medicine agencies.

The higher risk of venous thromboembolism with 3rd and 4th- generations combined oral contraceptives compared to 2nd generation triggered a media crisis in France. Exposure to 3rd or 4th-generation combined oral contraceptives led to an annual excess of around 100 premature deaths in Europe. In the absence of any demonstrated additional benefit of these combined oral contraceptives, measures were taken to decrease exposure of women to this illegitimate excess of risk. As a consequence, this crisis saw a 45% decrease in the prescription of 3rd and 4th-generations combined oral contraceptives, without adverse consequences.