Use of ropivacaine and lidocaine for axillary plexus blockade.

OBJECTIVE: The use of certain peripheral nerve blocks in paediatric patients is gaining increasing popularity, although distinctive characteristics of the juvenile anatomy, psychological barriers, time constraints on block placement, and risks of neurotoxic and cardio toxic side effects are still mentioned. However, newer agents like Ropivacaine and Levobupivacaine seem to offer excellent alternatives to Bupivacaine and Lidocaine, especially for use in paediatric patients. MATERIALS AND METHODS: We evaluated Ropivacaine 0.5% and Lidocaine 1.0% using axillary plexus blockade as a single-shot technique in 50 children in the age group of 2 to 10 years and undergoing short upper limb surgery. The primary objectives were to compare onset time, duration and quality of block and the incidence of breakthrough pain. RESULTS: Onset time was longer in the Ropivacaine group (15.4 minutes) than in the Lidocaine group (8.2 minutes). The duration of the effect was greater in patients in the Ropivacaine group (337 minutes) than in the Lidocaine group (137 minutes). Duration appeared to vary with patient's age but this effect was not statistically significant. CONCLUSION: Axillary plexus anaesthesia provides satisfactory perioperative pain relief in infants undergoing short-trauma surgery. Apart from its safety, these results underline that Ropivacaine 0.5% can be recommended for axillary brachial plexus block in children.

Ultrasound of the lateral femoral cutaneous nerve: normal findings in a cadaver and in volunteers.

OBJECTIVE: To assess the feasibility of ultrasound (US) in visualizing the lateral femoral cutaneous nerve (LFCN) in a cadaver and 8 volunteers. METHODS: Ultrasound and US-guided dye injection was performed in 1 cadaver to show the feasibility of detecting the LFCN. We then performed US in 8 volunteers to assess position of the nerve in respect to the anterior iliac spine. We subsequently performed US-guided anesthetic block of the LFCN on both sides with 0.3 mL local anesthetic. Success rate, time to maximum peak blockade, and duration of blockade were noted. RESULTS: Ultrasound allowed visualization of the LFCN in the cadaveric specimen on both sides and in all but 1 volunteer. Ultrasound-guided block of the LFCN was successful in all but 1 volunteer. The mean distance of LFCN from the anterior iliac spine was 2.9 cm on the right side and 2.8 cm on the left side. The mean duration of the block was 4.4 hours. CONCLUSION: Ultrasound enables visualization of the LFCN in a cadaver and in volunteers. Ultrasound-guided injection successfully blocked the LFCN.

Ilioinguinal/iliohypogastric blocks in children: where do we administer the local anesthetic without direct visualization?

BACKGROUND: Ultrasonographic observation of peripheral nerve blocks enables direct visualization of the spread of local anesthetic around the targeted nerves. Similarly, ultrasonography may be used to determine the site of local anesthetic placement when landmark-based techniques are used. We performed a study to determine the actual location of local anesthetic when ilioinguinal/iliohypogastric nerve blocks are performed using landmark-based techniques in children in an attempt to explain a failed block. METHODS: After induction of general anesthesia (1 minimum alveolar anesthetic concentration halothane and laryngeal mask airway), 62 children scheduled for inguinal surgery received an ilioinguinal/iliohypogastric nerve block based on standard anatomical landmarks. Ultrasonography was then used to determine the actual location of local anesthetic placement. The anesthesiologist performing the block was blinded to the ultrasonographic investigation. Successful blocks were recorded either when the local anesthetic surrounded the nerves or were based on clinical signs after skin incision. RESULTS: In 14% of the blocks, the local anesthetic was administered correctly around the nerves resulting in successful blocks. In the remaining 86%, the local anesthetic was administered in adjacent anatomical structures (iliac muscle 18%, transverse abdominal muscle 26%, internal oblique abdominal muscle 29%, external oblique abdominal muscle 9%, subcutaneous 2%, and peritoneum 2%), and 45% of these blocks failed. CONCLUSION: Accurate placement of local anesthetic around the ilioinguinal/iliohypogastric nerves in children is seldom possible when landmark-based techniques are used. In the majority of patients, the local anesthetic was inaccurately placed in adjacent anatomical structures with unpredictable block results.

Experience of recombinant activated factor VII (NovoSeven) in the operating theatre and intensive care unit for the management of intracranial bleeding in nonhaemophilic patients.

OBJECTIVE: Intracranial haemorrhage (ICH) is associated with high morbidity and mortality. Our aim was to explore the use of recombinant activated factor VII (rFVIIa NovoSeven Novo Nordisk, A/S, Bagsvaerd, Denmark) for the management of ICH in the operating theater and intensive care unit. PATIENTS AND METHODS: We reviewed all the records of nonhaemophilic patients entered into the haemostasis.com database who received rFVIIa for ICH. RESULTS: Sixteen suitable patients were identified (mean age: 23.3 years; range: 1-58 years). The total dose of rFVIIa administered ranged from 31 to 270 microg/kg. Indications were stabilization of ICH (n=6), control of peri- or post-operative haemorrhage associated with neurosurgical procedures (n=8), or correction of coagulopathy prior to neurosurgical intervention (n=2). The majority (13/16 [81.25%]) required one dose of rFVIIa. A clinical effect (stabilization of bleed, reduction of peri- or post-operative haemorrhage, or prevention of excessive blood loss during neurosurgery) was seen in 14/16 (87.5%) patients. Some improvement in coagulation status was noted. No thromboembolic events were reported. One patient experienced massive elevation of D-dimer levels-an effect possibly due to rFVIIa. Two patients suffered adverse events unrelated to rFVIIa. Six deaths occurred, all attributable to underlying brain injury. CONCLUSION: This observational study suggests that rFVIIa is of value for the management of ICH in nonhaemophilic patients secondary to a range of aetiologies. These findings justify further investigation.

Postoperative vigilance in patients with total intravenous anaesthesia with ketamine/propofol.

Ketamine is a strong acting analgesic drug, used mainly in trauma and emergency medicine settings, as well as for minor procedures. Its pharmacological properties make it a useful drug for military anaesthesia. Ketamine acts by blocking activation of the spinal and supraspinal NMDA-type glutamate and opioid receptors. It produces dissociative anaesthesia, which means that patients might remain conscious, though insensitive to pain and amnesic (anterograde). Dysphoria and hallucinations are the main side effects in the early recovery period. We studied the incidence of post operative nausea and vomiting, vigilance disturbances and haemodynamic instability during combined ketamine and propofol anaesthesia. No patient suffered from postoperative nausea and vomiting. No haemodynamic instability could be observed in any of the patients. The interesting point is that though there were no unpleasant emergence phenomenons, no patient reached the preoperative state of vigilance within two hours after extubation. These results indicate that for plastic/dermatological surgical procedures, patients undergoing ketamine/propofol anaesthesia do not require excessive haemodynamic monitoring, but do need prolonged personal observation in the postoperative period.

Effect of prostacyclin on platelets, polymorphonuclear cells, and heterotypic cell aggregation during hemofiltration.

OBJECTIVES: Hemodialysis activates both platelets and leukocytes, which play a role in the development of multiple organ dysfunctions in critically ill patients. Prostacyclin inhibits both cell types. To examine the hypothesis that prostacyclin prevents cellular activation during clinical hemofiltration, we investigated the expression of activation markers on platelets and leukocytes using whole blood flow cytometry. DESIGN: Prospective, randomized, double-blind, controlled trial. SETTING: Intensive care unit. PATIENTS: A total of 24 consecutive, critically ill, mechanically ventilated patients with acute renal failure secondary to sepsis or major surgery. INTERVENTIONS: For anticoagulation during hemofiltration, patients received either unfractionated heparin or unfractionated heparin and prostacyclin (5 ng x kg(-1) x min(-1)). Anticoagulants were administered into the extracorporeal circuit before the hemofilter. Blood samples were obtained from an arterial catheter before hemofiltration and from the inlet and outlet lines of the extracorporeal circuit at 1 and 24 hrs during hemofiltration. MEASUREMENTS AND MAIN RESULTS: Expression of GP IIb-IIIa and P-selectin on adenosine diphosphate-activated platelets and platelet-leukocyte aggregation were significantly lower after the passage of blood through the hemofilter in patients receiving an extracorporeal infusion of prostacyclin plus heparin when compared with control patients receiving heparin only. There were no statistically significant differences in the expression of CD11b on leukocytes between the two groups. CONCLUSIONS: These findings suggest that prostacyclin reversibly inhibits platelet function by diminishing the expression of platelet fibrinogen receptors and P-selectin and reduces heterotypic platelet-leukocyte aggregation during clinical hemofiltration. However, prostacyclin fails to inhibit leukocyte activation at clinically relevant doses.

Comparison of in vitro closure time (PFA-100) with whole blood electrical aggregometry and platelet surface antigen expression in healthy volunteers.

It was the aim of this study to compare in vitro closure time (PFA-100), reflecting platelet-related primary hemostasis, to more platelet-specific tests like whole blood electrical aggregometry and platelet surface antigen expression in healthy volunteers. In vitro closure time was measured using a PFA-100. Platelet surface antigen expression (CD63, CD62-P, CD42b, CD36, CD31) was determined in accordance with the consensus protocol for flow-cytometric characterisation of platelet function. Platelet aggregometry was performed using a whole blood electrical aggregometer (ADP and arachidonic acid as agonists). Analysis of the obtained data revealed only a few significant correlations between the different platelet function tests used. This finding can be explained by the various aspects of platelet function being focused by these tests in different extents. Whenever platelet function is analysed, the investigator should be aware of the specific and limited evidence of the method used. For screening purposes, it may be useful to introduce a platelet function index, referring to basal platelet activity, platelet adhesion and platelet aggregation at low and high shear stress forces.