Tubing Spallation in Extracorporeal Circuits. An in Vitro Study Using an Electronic Particle Counter

1992 ◽  
Vol 15 (4) ◽  
pp. 222-228 ◽  
Author(s):  
J.C. Briceño T. ◽  
T. M. Runge
Keyword(s):  
Flow Rate ◽  
In Vitro Study ◽  
Blood Flow Rate ◽  
Vitro Study ◽  
Occlusion Pressure ◽  
Roller Pump ◽  
Extracorporeal Circuits ◽  
Electronic Particle Counter ◽  
Particle Counts

The roller pump is the most common pumping device used in extracorporeal circulation (ECC). The interaction between the roller and tubing causes tubing spallation. Spallation has been associated with complications in ECC. Previous spallation studies present mixed results, including a decrease in the number of circulating particles. The objective of this work is to perform an in vitro study of tubing spallation which elucidates the causes of the particle sequestration, and the effect of tubing material, blood flow rate and duration of the procedure upon spallation. A sampling method minimizing background counts was devised. Silicone and PVC tubing were tested under normal and tight occlusion pressure at typical cardiopulmonary bypass and hemodialysis flow rates, for circulating times up to 4 h. Occlusion pressure and flow rate highly influenced the amount of spallation produced. Particle sequestration was noted and aggregation of the plastic particles was demonstrated. We conclude that, at least in vitro, aggregation causes the decrease in the particle counts and the misleading results obtained in most spallation studies using a Coulter counter.

Effects of Annular Size, Transmitral Pressure, and Mitral Flow Rate on the Edge-To-Edge Repair: An In Vitro Study

2006 ◽  
Vol 82 (4) ◽  
pp. 1362-1368 ◽  
Author(s):  
Jorge H. Jimenez ◽  
Joseph Forbess ◽  
Laura R. Croft ◽  
Lisa Small ◽  
Zhaoming He ◽  
...  
Keyword(s):  
Flow Rate ◽  
In Vitro Study ◽  
Vitro Study ◽  
Mitral Flow

Effect of HFNC flow rate, cannula size, and nares diameter on generated airway pressures: An in vitro study

2012 ◽  
Vol 48 (5) ◽  
pp. 506-514 ◽  
Author(s):  
Emidio M. Sivieri ◽  
Jeffrey S. Gerdes ◽  
Soraya Abbasi
Keyword(s):  
Flow Rate ◽  
In Vitro Study ◽  
Vitro Study ◽  
Airway Pressures

scholarly journals Influence of orifice geometry and flow rate on effective valve area: An in vitro study

1990 ◽  
Vol 15 (5) ◽  
pp. 1173-1180 ◽  
Author(s):  
Frank A. Flachskampf ◽  
Arthur E. Weyman ◽  
J.Luis Guerrero ◽  
James D. Thomas
Keyword(s):  
Flow Rate ◽  
In Vitro Study ◽  
Vitro Study ◽  
Valve Area

Heparinase I (Neutralase) Reversal of Systemic Anticoagulation

1996 ◽  
Vol 85 (2) ◽  
pp. 339-346 ◽  
Author(s):  
Luis G. Michelsen ◽  
Mutsuhito Kikura ◽  
Jerrold H. Levy ◽  
Mi Kyoung Lee ◽  
King C. Lee ◽  
...  
Keyword(s):  
Adverse Reactions ◽  
In Vitro Study ◽  
Vitro Study ◽  
Heparin Anticoagulation ◽  
Extracorporeal Circuits ◽  
Anesthetized Dogs ◽  
Heparinase I ◽  
Canine Study

Background Protamine causes multiple adverse reactions. Heparinase I, a specific enzyme that inactivates heparin, is a possible alternative to protamine. In this study, the authors examined the efficacy of heparinase I to reverse heparin-induced anticoagulation in vitro and compared heparinase I to protamine as an antagonist of heparin-induced anticoagulation in dogs. Methods In the in vitro study, blood was obtained from the extracorporeal circuits of 12 patients, and activated clotting times were determined after adding different concentrations of heparinase I. In the in vivo study, 24 anesthetized dogs received 300 units/kg heparin injected intravenously for 5 s, then 10 min later, 3.9 mg/kg protamine, 5-41 micrograms/kg heparinase I, or the vehicle (n = 4/group) were administered intravenously, and activated clotting times and hemodynamics were measured. Results In the in vitro study, heparin concentrations of 3.3 +/- 1.0 (mean +/- SD) units/ml (approximately 0.033 mg/ml; n = 12) were reversed in the blood of patients by heparinase I at concentrations > 0.490 microgram/ml. In the canine study, heparinase at all doses studied and protamine effectively reversed the anticoagulating effects of heparin within 10 min of administration. Protamine produced adverse hemodynamic effects, whereas heparinase or its vehicle produced no significant change in arterial pressure. Conclusion Both heparinase I and protamine effectively reversed heparin anticoagulation. However, as opposed to protamine, heparinase I did not produce any significant hemodynamic changes when given as a bolus to dogs.

Nebulizers and spacers for aerosol delivery through adult nasal cannula at low oxygen flow rate: An in-vitro study

2017 ◽  
Vol 39 ◽  
pp. 260-265 ◽  
Author(s):  
Yasmin M. Madney ◽  
Maha Fathy ◽  
Ahmed A. Elberry ◽  
Hoda Rabea ◽  
Mohamed E.A. Abdelrahim
Keyword(s):  
Flow Rate ◽  
In Vitro Study ◽  
Oxygen Flow Rate ◽  
Nasal Cannula ◽  
Vitro Study ◽  
Oxygen Flow ◽  
Aerosol Delivery ◽  
Low Oxygen

Relevance Of Plasma alpha 2 Antiplasmin Measurement For Monitoring The Occurrence Of A Thrombolytic State During Urokinase Therapy. An In-Vitro Study

1981 ◽  
Author(s):  
V Musumeci ◽  
B Zappacosta
Keyword(s):  
Flow Rate ◽  
Whole Blood ◽  
In Vitro Study ◽  
Vitro Study ◽  
Peristaltic Pump ◽  
Laboratory Parameters ◽  
Chamber Volume ◽  
Perfusion Chamber ◽  
Glass Tubes

The aim of the present study was the search of changes in laboratory parameters which can be reliably correlated to the development of an effective thrombolytic state during urokinase therapy. Artificial radiolabelled venous thrombi were prepared by leaving native blood (0.1 ml) to clot in glass tubes for 2 hours in presence of 1-2 μCi of 125I fibrinogen (Sorin Saluggia, Italy). The labelled clots were introduced into a perfusion chamber (volume 0.2 ml) provided with a plastic retention screen and placed in the focus of the detector of a Pitman Ratemeter model 235 N connected to a recorder. The perfusion chamber was connected in a close circuit through a peristaltic pump to a reservoir containing citrated whole blood (15 ml) maintained at 37°C under continuous stirring. Blood was pumped through the chamber at a flow rate of 1 ml/min. Urokinase was introduced in increasing amounts in the reservoir during a period of 5 hours and at various intervals aliquots of blood (0.3 ml) were drawn and assayed after centrifugation for plasminogen, alpha 2 antiplasmin and fibrinogen. Alpha 2 antiplasmin was assayed by using Coatest Antiplasmin from Ortho Diagnostics. Plasminogen was assayed after SK activation by using the substrate S 2251 from Ortho Diagnostics. Results showed that an effective thrombolytic states, as detected by a decrease of clot radioactivity, appeared when alpha 2 antiplasmin concentration fell at levels below 40%. The alpha 2 antiplasmin measurement could be useful for monitoring the thrombolytic effectiveness of non-standard low or moderate dosages of urokinase therapy.

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