Hypersensitivity reactions to Patent Blue V in breast cancer surgery: a prospective multicentre study.

BACKGROUND: An increasing number of immediate hypersensitivity reactions (HSR) have been reported after the use of Patent Blue V (PBV) for breast cancer surgery. This is the first study to publish prospective data with systematic allergological assessment. METHODS: We conducted a multicentre study in 10 French cancer centres for over 6 months. All patients scheduled for breast surgery with injection of PBV were included in the study. Patients were screened for past medical history, atopy, and known food and drug allergies. When suspected HSR or unexplained reactions occurred after injection of PBV, blood samples were taken, and plasma histamine and serum tryptase concentrations were measured. HSR to PBV was suggested if skin tests performed 6 weeks later were positive. RESULTS: Nine suspected HSR to PBV were observed in 1742 patients. Skin tests were positive in six patients, giving an incidence of 0.34%. Four grade I and two grade III HSR were observed, both requiring intensive care unit treatment. Mean onset time of the reaction was 55 ± 37 min. Plasma histamine was elevated in four patients, while serum tryptase was normal. We found no risk factors associated with HSR to PBV. CONCLUSION: An incidence rate of one in 300 HSR to PBV was observed for patients exposed to PBV during sentinel lymph node detection. This rate is higher than rates reported after the use of neuromuscular blocking agents, latex or antibiotics.

The design of venous thromboembolism prophylaxis trials: is enoxaparin more effective than fondaparinux?

The aim of thromboprophylaxis is to minimise the incidence of clinically relevant venous thromboembolism (VTE) but in many trials designed to determine the efficacy of thromboprophylactic agents, asymptomatic VTE is included in the primary endpoint. Since asymptomatic events occur much more frequently than symptomatic events, they dominate the results. Data from trials comparing the thromboprophylactic efficacy of enoxaparin and fondaparinux in orthopaedic surgical patients are used to demonstrate that asymptomatic and symptomatic endpoints may yield different conclusions. There was no difference between these agents in the incidence of symptomatic VTE. Efficacy and safety results of thromboprophylactic studies are affected by other aspects of trial design such as the dose of each agent and the timing of treatment initiation and endpoint assessment. Such factors should be considered when designing clinical trials and evaluating their results.

The comparative electrophysiologic and hemodynamic effects of a large dose of ropivacaine and bupivacaine in anesthetized and ventilated piglets.

UNLABELLED: Ropivacaine is less potent and less toxic than bupivacaine. We administered these two local anesthetics in a cardiac electrophysiologic model of sodium thiopental-anesthetized and ventilated piglets. After assessing the stability of the model, bupivacaine (4 mg/kg) and ropivacaine (6 mg/kg) were given IV in two groups (n = 7) of piglets. No alteration in biological variables was reported throughout the study. Bupivacaine and ropivacaine similarly decreased mean aortic pressure from 99 +/- 22 to 49 +/- 31 mm Hg and from 87 +/- 17 to 58 +/- 28 mm Hg, respectively, and decreased the peak of the first derivative of left ventricular pressure from 1979 +/- 95 to 689 +/- 482 mm Hg/s and from 1963 +/- 92 to 744 +/- 403 mm Hg/s, respectively. Left ventricular end-diastolic pressure was similarly increased from 6 +/- 5 to 9 +/- 5 mm Hg and from 6 +/- 4 to 12 +/- 4 mm Hg, respectively. Bupivacaine and ropivacaine similarly lengthened the cardiac cycle length (R-R; from 479 +/- 139 to 706 +/- 228 ms and from 451 +/- 87 to 666 +/- 194 ms, respectively), atria His (from 71 +/- 15 to 113 +/- 53 ms and from 64 +/- 6 to 86 +/- 10 ms, respectively), and QTc (QTc = QT x R-R(-0.5), Bazett formula; from 380 +/- 71 to 502 +/- 86 ms and from 361 +/- 33 to 440 +/- 56 ms, respectively) intervals. Bupivacaine altered to a greater extent the PQ (the onset of the P wave to the Q wave of the QRS complex) (from 97 +/- 20 to 211 +/- 60 ms versus from 91 +/- 8 to 145 +/- 38 ms, P < 0.05), QRS (from 58 +/- 3 to 149 +/- 34 ms versus from 60 +/- 5 to 101 +/- 17 ms, P < 0.05), and His ventricle interval (from 25 +/- 4 to 105 +/- 30 ms vs from 25 +/- 4 to 60 +/- 30 ms, P < 0.05) than ropivacaine. A 6 mg/kg ropivacaine dose induced similar hemodynamic alterations as 4 mg/kg bupivacaine. However, bupivacaine altered the variables of ventricular conduction (QRS and His ventricle) to a greater extent. IMPLICATIONS: A 6 mg/kg ropivacaine dose induced similar hemodynamic alterations as 4 mg/kg bupivacaine. However, bupivacaine altered the variables of ventricular conduction (QRS and His ventricle) to a greater extent.

The continuous femoral nerve block catheter for postoperative analgesia: bacterial colonization, infectious rate and adverse effects.

UNLABELLED: We investigated the incidence of bacterial and vascular or neurological complications resulting from femoral nerve catheters used for postoperative analgesia. Patients requiring continuous femoral blockade were consecutively included. Using surgical aseptic procedure, 211 femoral nerve catheters were placed (short-beveled insulated needle, peripheral nerve stimulator). After 48 h, each catheter was removed and semiquantitative bacteriological cultures were performed on each distal catheter tip. Postoperative analgesia and antibiotics were standardized. All complications during the insertion of the catheters and postoperatively (after 48 h and 6 wk) were noted. Few initial complications with no immediate or delayed complications were noted (20 difficult insertions, 3 impossible injections, 3 ineffective catheters, and 12 vascular punctures). After 48 h, 208 catheters were analyzed; 57% had positive bacterial colonization (with a single organism in 53%). The most frequent organisms were Staphylococcus epidermidis (71%), Enterococcus (10%), and Klebsiella (4%). Neither cellulitis nor abscess occurred. Three transitory bacteremias likely related to the catheter occurred. After 6 wk, no septic complications were noted. One femoral paresthesia, partially recovered 1 yr later, was noted. We conclude that the risk of bacterial complications is small with femoral nerve catheters, although the rate of colonization is frequent. IMPLICATIONS: In this prospective study, continuous femoral nerve catheters were effective for postoperative analgesia but had a frequent rate of bacterial catheter colonization. We found no serious infections after short-term (2-day) infusion. Side effects were few, but one nerve injury occurred.

[Locoregional anesthesia in digestive surgery]. / L'anesthésie locorégionale en chirurgie digestive.

Many regional anesthetic techniques can be used in the setting of abdominal surgery. Spinal anesthesia has limited indications for lower abdominal surgery (below T10), especially abdominal wall surgery and anal surgery. Indications of epidural anesthesia are quite similar, while epidural analgesia can be extensively used for postoperative analgesia, provided great attention is paid to strict monitoring and safety rules. Finally, peripheral regional anesthetic techniques are discussed, highlighting their advantages in this particular setting.

Medial canthus (caruncle) single injection periocular anesthesia.

We studied 151 consecutive patients scheduled for elective short-duration ophthalmic procedures to assess the efficacy of an alternative approach to periocular anesthesia. Single injection at the medial canthus was performed with a 25-gauge needle. The studied variables were: injected volume, onset time of the block, akinesia (scored on a 12-point scale), adequate surgical anesthesia (scored on a 5-point scale), and need for reinjection. The injected volume of local anesthetic solution was 8.6 +/- 1.7 mL. The onset time of anesthesia was 6.9 +/- 3.0 min, with an akinesia score of 11.6 +/- 1.1 (maximum 12). Additional reinjections were necessary in 14 cases (9.2%). There was a learning curve for the technique, with 8 of the additional injections being performed in the first 30 patients (26.6%), and 6 in the last 121 (4.9%). The surgical score recorded after surgery was 4.8 +/- 0.6 (maximum 5). There were no complications, including injury to the globe, optic nerve, or retina or orbital hematoma. Medial canthus single injection periocular anesthesia appears to be a promising alternative to the usual double injection peribulbar block.

[Severe preeclampsia. Principal management modalities before patient transfer]. / Pré-éclampsie sévère. Principales modalités de la prise en charge avant transfert.

Preeclampsia is relatively frequent during pregnancy. The occurrence of complications implies referral to a specialized center for optimal care of both mother and fetus. The transfer of these patients is very critical with risk of worsening the mother's status. Management before referral aims to stabilize material clinical status, requiring precise clinical assessment, treatment of severe hypertension or pulmonary edema, and prevention or treatment of eclampsia. The management of oliguria and the tracheal intubation are associated with specific problems. Fetal wellbeing is assessed before and during emergency treatments of maternal disorders.

[Does neuroplasticity have a role on postoperative pain?]. / La neuroplasticité intervient-elle dans les phénomènes douloureux postopératoires?

The neurophysiologic concept of neuroplasticity represents one of the current basis of the pathophysiology of painful post-injury phenomenons (postoperative, post-traumatic...). Deriving directly from these experimental data, the idea of preemptive analgesia has gradually developed in the last five years, the central question being to know if an analgesic intervention preceding surgical intervention is more efficient, as efficient, or less efficient than the same intervention following surgery. The authors bring current data of the literature in favor of the role of neuroplasticity in the genesis and the persistence of painful states in the course of postoperative outcome. A review of the various clinical studies and controversies published is proposed, in the attempt to make the point on current therapeutic implications of the concept of preemptive analgesia.

[Optimal use of peripheral nerve blocks]. / Optimisation des blocs périphériques.

The advantages of regional over general anaesthesia have led to an increased use of peripheral nerve blocks. Among the few risks of regional anaesthesia are those of overdosage, systemic and neural toxicity. Techniques have been proposed to improve the success of peripheral nerve blocks and to avoid nerve damage or systemic toxicity. Nerve stimulator, anatomic landmarks, needles and anaesthetic solutions are discussed.