Effectiveness of biplane angiography compared to monoplane angiography for vascular neuro-interventions: a systematic review of the literature.

AIM: To compare biplane technology to monoplane technology for vascular neuro-intervention. MATERIALS AND METHODS: A systematic review of the literature in MEDLINE (via PubMed), Scopus, and ScienceDirect was conducted without date or language restrictions. The Downs and Black quality-assessment checklist was used. The findings of this systematic review were combined with local and Canadian data. RESULTS: The nine articles selected for analysis had a very low level of evidence. The studies report that the biplane system appears to reduce ionising radiation and medical complications as well as shorten procedure time. Most major hospitals in Canada use the biplane system. The biplane system could improve the operator's confidence, which could translate into reduced risk, especially for more complex procedures. CONCLUSION: The superiority of the biplane system cannot be scientifically proven based on the data in the literature. Nevertheless, given the advantages that a biplane system can provide in terms of safety, quality of care, support to university teaching programmes based on best practices, enhanced capability in performing complex procedures, this technology should be implemented with a responsibility to collect outcome data to optimise the clinical protocol regarding the dose of ionising radiation delivered.

Quantitative assessment of haemolysis secondary to modern infusion pumps.

BACKGROUND: Although most studies have shown that little haemolysis is induced by infusion pumps, there are some notable exceptions. Only limited data are available on the actual infusion pumps that are most used in hospitals in Quebec and elsewhere, namely, the Infusomat® Space (peristaltic), Plum A+™ (piston) and Colleague® CXE (shuttle) pumps. METHODS: Haemolysis and potassium levels were compared before and after the use of the three different infusion pumps. Using 135 units of packed red blood cells (RBCs) aged from 10 to 28 days, 27 measurements were taken for each pump at various flow rates (30, 60, 150, 300 and 450 ml/h) and were compared with measurements taken before using the pumps. The range of flow rates was chosen to cover those of paediatric and adult transfusions. RESULTS: The shuttle- and piston-type pumps resulted in low haemolysis levels. The peristaltic-type pump produced significantly more haemolysis, which worsened at low flow rates, but the absolute value of haemolysis remained within the range recommended by the regulatory agencies in North America and Europe. Approximately two-thirds of the haemolysis produced by the peristaltic-type pump seemed to be secondary to the use of an antisiphon valve (ASV) on the transfusion line recommended by the manufacturer. Potassium levels did not increase with the use of the pumps. CONCLUSION: Modern infusion pumps widely used in hospitals in Quebec and elsewhere produce non-threatening levels of haemolysis during the transfusion of packed RBCs aged from 10 to 28 days. ASVs appear to induce additional haemolysis, and we do not recommend using them for blood transfusion.

Effect of warming and flow rate conditions of blood warmers on red blood cell integrity.

BACKGROUND AND OBJECTIVES: Fluid warmers are routinely used to reduce the risk of hypothermia and cardiac complications associated with the infusion of cold blood products. However, warming blood products could generate haemolysis. This study was undertaken to compare the impact of temperature of blood warmers on the per cent haemolysis of packed red blood cells (RBCs) heated at different flow rates as well as non-flow conditions. MATERIALS AND METHODS: Infusion warmers used were calibrated at 41·5°C ± 0·5°C and 37·5°C ± 0·5°C. Cold RBC units stored at 4°C in AS-3 (n = 30), aged 30-39 days old, were divided into half units before being allocated under two different scenarios (i.e. infusion pump or syringe). RESULTS: Blood warmers were effective to warm cold RBCs to 37·5°C or 41·5°C when used in conjunction with an infusion pump at flow rate up to 600 ml/h. However, when the warmed blood was held in a syringe for various periods of time, such as may occur in neonatal transfusions, the final temperature was below the expected requirements with measurement as low as 33·1°C. Increasing the flow with an infusion pump increased haemolysis in RBCs from 0·2% to up to 2·1% at a flow rate of 600 ml/h regardless of the warming device used (P < 0·05). No relevant increase of haemolysis was observed using a syringe. CONCLUSIONS: The use of a blood warmer adjusted to 41·5°C is probably the best choice for reducing the risk of hypothermia for the patient without generating haemolysis. However, we should be cautious with the use of an infusion pump for RBC transfusion, particularly at high flow rates.

[Advantages and disadvantages of water birth. A systematic review of the literature]. / Bénéfices et risques de l'accouchement dans l'eau: une revue systématique.

CONTEXT: Water birth is under debate among professionals. For the proponents of this approach, immersion in water during labour and birth may increase maternal relaxation, reduce analgesia requirements and promote a model of obstetric care more focused on the needs of mothers, particularly the empowerment of women to realize their full potential. In contrast, major critics cite a risk of inhalation of water for the newborn and a risk of infection for the mother and the newborn. OBJECTIVE: This review tracks the state of scientific knowledge about water birth in order to determine if it can be generalized in hospitals. METHOD: A systematic review of the literature was conducted in PubMed, Embase and Cochrane Database. The period covered is from January 1989 to May 2013. The level of evidence of the studies was assessed with the analysis guide of the Haute Autorité de santé. RESULTS: The level of evidence of the studies identified goes from moderate to low, particularly as regard to studies analysing the expulsion phase. CONCLUSION: It is possible to recommend immersion in water during the labour phase. No recommendation can be made as regard to the foetal expulsion phase.

Implantable Doppler in monitoring free flaps: a cost-effectiveness analysis based on a systematic review of the literature.

OBJECTIVE: The purpose of this paper is to evaluate the efficacy and cost-effectiveness of the implantable Doppler system based on the analysis of the available scientific literature and clinical and cost data available in our hospital. The results of this system are compared to those of conventional free flap monitoring methods. MATERIALS AND METHODS: The literature published between 1991 and 2011 was systematically reviewed. All available cost data were collected and several simulations were performed. A retrospective assessment of the efficacy of conventional methods in our hospital was also conducted. RESULTS AND CONCLUSION: The implantable Doppler system is more effective than the conventional methods used to monitor free flap perfusion. The mean flap salvage rate with the implantable Doppler was 21 percentage points higher (81.4 vs. 60.4). The excess cost compared to conventional methods was about CAD 120 per patient (about EUR 94). However, this excess cost can be compensated or even reversed, depending on the initial flap salvage rate in the health facility and the type of free flap (buried vs. non-buried).

Contraction of reptile, amphibian, and fish blood vessels by endothelin-1.

Endothelin-1, a 21 amino acid peptide originally isolated from porcine endothelial cells, has been reported to contract arteries and veins from several mammalian species. We studied the effect of endothelin-1 on blood vessels removed from turtle (Pseudymes scripta), frog (Rana pipiens), and catfish (Amiurus melas). The vessels were suspended for isometric recording in thermally controlled organ baths and were exposed cumulatively to endothelin-1 (0.5-100 nM). All vessels showed a concentration-dependent increase in isometric force. The half-maximal concentrations (EC50) of endothelin-1 were all in the nanomolar range: turtle left systemic arch (17.9 +/- 1.2 nM), frog systemic arch (5.5 +/- 1.1 nM), catfish mesenteric artery (6.3 +/- 1.3 nM), and catfish posterior cardinal vein (2.5 +/- 1.4 nM). Vessels from frog and catfish developed more tension when exposed to 100 nM endothelin-1 than to 80 mM KCl (ET/KCl tension ratio). Our observations that endothelin-1 potently contracts blood vessels from reptiles, amphibians, and fish suggest that endothelin-1 may be a vertebrate peptide that has been conserved during evolution.

Calcium channel agonist and antagonist binding in a highly enriched sarcolemma preparation obtained from canine ventricle.

The purpose of the present study was to characterize the binding of the Ca2+ channel agonist (+/-)[3H]Bay K 8644 in a highly enriched cardiac membrane preparation and to examine its interactions with other Ca2+ channel ligands. Scatchard analysis showed that (+/-)[3H]Bay K 8644 displayed some 265-fold less affinity for its receptor than did the Ca2+ channel antagonist (+)[3H]PN200-110. Furthermore, (+/-)[3H]Bay K 8644 binding site density was significantly less than that seen for (+)[3H]PN200-110. Kinetic analysis of (+/-)[3H]Bay K 8644 binding revealed biphasic association and dissociation rates. The Ca2+ channel antagonist MDL 12,330A stimulated both (+)[3H]PN200-110 and (+/-)[3H]Bay K 8644 binding by effects on Kd. In contrast, diltiazem inhibited (+)[3H]PN200-110 binding but had no effect on (+/-)[3H]Bay K 8644 binding. Both MDL 12,330A and diltiazem inhibited Ca2+-dependent contraction in rat aortic rings but the combination of these two drugs was less than additive in this regard. We conclude that the binding profile of (+/-)[3H]Bay K 8644 results from the racemic nature of this ligand and that MDL 12,330A and diltiazem interact at sites distinct from one another on or around the slow voltage-dependent Ca2+ channel.

Endothelin increases single-channel calcium currents in coronary arterial smooth muscle cells.

Endothelin (ET), a newly identified vasoconstrictor peptide produced by endothelial cells, depends on extracellular calcium for its action [(1988) Nature 332, 411-415]. It is not yet known whether the increase in calcium influx induced by ET results from a direct effect on the Ca2+ channels or is secondary to a reduction in membrane potential. To address this question, we studied the effects of ET on single-channel calcium currents of freshly dissociated porcine coronary artery smooth muscle cells using the cell-attached mode of the patch-clamp technique. We show that ET increases Ca2+-channel activity with no effect on channel open time or conductance. The ability of bath-applied ET to increase single-channel calcium currents in the cell-attached mode is evidence that the peptide acts via a second messenger system.

Evaluation of a microcrystalline bovine collagen hemostatic agent in canine solid viscera injury using abdominal impedance plethysmography.

Bioelectric impedance as a sensitive noninvasive technique for detecting and monitoring changes in compartmental body fluid volume was used to compare the efficacy of two hemostatic agents in controlling postoperative abdominal bleeding following surgically induced solid viscera injury. Gelatin foam-oxidized cellulose sponge and bovine MCHH were both effective topical hemostatic agents. It appears that MCCH has certain advantages over conventional agents.