Ultrasound-guided locoregional anaesthesia for carotid endarterectomy: a prospective observational study.

INTRODUCTION: Ultrasound guidance is increasingly used for invasive anaesthetic procedures to improve efficacy, facilitate performance and reduce risk of complications. Herein, we present a simple approach to ultrasound-guided locoregional anaesthesia for patients undergoing eversion carotid endarterectomy. METHODS: At the level of the base of the carotid bifurcation, the needle was inserted at the lateral border of the sternocleidomastoid muscle and, guided by ultrasound, advanced 0.5-1 cm posterolateral to the carotid artery, where ropivacaine (7.5 mg ml(-1)) was injected. During retraction of the needle, additional local anaesthetic was administered beneath the sternocleidomastoid muscle and, finally, subcutaneous infiltration along the surgical incision line was performed. The primary study end point was the amount of additional ropivacaine (7.5 mg ml(-1)) provided intra-operatively. Secondary measures included the occurrence of puncture-related complications and the adverse effects to locoregional anaesthesia. RESULTS: Sixty consecutive patients admitted for primary carotid endarterectomy were prospectively included. The volume of administered ropivacaine for locoregional anaesthesia and subsequent intra-operative supplementation was 31.7 ± 3.5 and 1.9 ± 2.5 ml, respectively. There were no conversions to general anaesthesia. Intravascular or subarachnoid injection of local anaesthetic did not occur, and symptoms of local anaesthetic systemic toxicity did not present. Related to the blockade, hoarseness (72%), Horner syndrome (37%), cough (20%), facial palsy (13%) and dysphagia (12%) were observed and resolved on the first postoperative day. CONCLUSIONS: This observational study demonstrates that the described ultrasound-guided locoregional anaesthesia is suitable for eversion carotid endarterectomy and the amount of supplemental anaesthetic during the surgery is low.

Initial administration of hydroxyethyl starch vs lactated Ringer after liver trauma in the pig.

BACKGROUND: This study tested the circulatory effectiveness of post-trauma administration of a large intravascular volume expander, hydroxyethyl starch 130/0.4 (HES), vs standard lactated Ringer's solution (RL). METHODS: Liver injury was inflicted in 14 pigs [31 (4) kg; mean (sd)] and treatment simulated an acute pre-hospital event: after a standard first-respond delay (7 min), volume administration was provided in three phases to simulate increasing intravascular access. In the first two phases, the fluid was administered either by HES or by RL and, during the last phase, all animals received HES to stabilize the intravascular volume. RESULTS: The liver trauma severed an equal number of 1-3 mm diameter blood vessels [1.4 (0.6)] and after 7 min, the blood loss was 184 (127) ml and mean arterial pressure had decreased by 19 (13) mm Hg (P<0.01). The intravascular volume expansion effect was 115 (25)% for HES and 76 (21)% for RL (P<0.05), yet oxygen uptake was maintained in zero of seven vs three of seven pigs and the survival was three of seven vs seven of seven, respectively (P<0.05). In these animals, the initial administration of HES provoked uncontrolled bleeding, whereas the administration of RL was associated with attenuated bleeding: total blood loss 2455 (1919) vs 311 (208) ml, respectively (P<0.01), reflecting that bleeding ceased in six of the pigs administered RL. CONCLUSIONS: After injury, the intravascular volume expanding effect of HES was larger than that for RL. However, initial administration of HES provoked uncontrolled haemorrhage, suggesting that prioritizing intravascular volume expansion did not result in stabilization of the circulation after haemorrhage.

Promiscuous and specific phospholipid binding by domains in ZAC, a membrane-associated Arabidopsis protein with an ARF GAP zinc finger and a C2 domain.

Arabidopsis proteins were predicted which share an 80 residue zinc finger domain known from ADP-ribosylation factor GTPase-activating proteins (ARF GAPs). One of these is a 37 kDa protein, designated ZAC, which has a novel domain structure in which the N-terminal ARF GAP domain and a C-terminal C2 domain are separated by a region without homology to other known proteins. Zac promoter/beta-glucuronidase reporter assays revealed highest expression levels in flowering tissue, rosettes and roots. ZAC protein was immuno-detected mainly in association with membranes and fractionated with Golgi and plasma membrane marker proteins. ZAC membrane association was confirmed in assays by a fusion between ZAC and the green fluorescence protein and prompted an analysis of the in vitro phospholipid-binding ability of ZAC. Phospholipid dot-blot and liposome-binding assays indicated that fusion proteins containing the ZAC-C2 domain bind anionic phospholipids non-specifically, with some variance in Ca2+ and salt dependence. Similar assays demonstrated specific affinity of the ZAC N-terminal region (residues 1-174) for phosphatidylinositol 3-monophosphate (PI-3-P). Binding was dependent in part on an intact zinc finger motif, but proteins containing only the zinc finger domain (residues 1-105) did not bind PI-3-P. Recombinant ZAC possessed GTPase-activating activity on Arabidopsis ARF proteins. These data identify a novel PI-3-P-binding protein region and thereby provide evidence that this phosphoinositide is recognized as a signal in plants. A role for ZAC in the regulation of ARF-mediated vesicular transport in plants is discussed.