Determining an Appropriate To-Keep-Vein-Open (TKVO) Infusion Rate for Peripheral Intravenous Catheter Usage

2021 ◽  
Author(s):  
Barry Doyle ◽  
Lachlan Kelsey ◽  
Peter J. Carr ◽  
Andrew Bulmer ◽  
Samantha Keogh
Keyword(s):  
Shear Stress ◽  
Infusion Rate ◽  
Venous Blood ◽  
Blood Stasis ◽  
Venous Blood Flow ◽  
Venous Flow ◽  
Flow Rates ◽  
Fluid Load ◽  
Peripheral Intravenous Catheter ◽  
Intravenous Catheters

Highlights Abstract Background: Evidence to support an optimum continuous to-keep-vein-open (TKVO) infusion rate for peripheral intravenous catheters (PIVCs) is lacking. The aim of this study was to simulate typical TKVO rates, in combination with flushing, to better understand TKVO in relation to PIVC patency. Methods: We simulated saline infusion through a 20-gauge PIVC in 2 forearm veins (3.3 and 2.2 mm) using computational fluid dynamics under various venous flow rates (velocities 3.7–22.1 cm/s), with a saline flush rate of 1 mL/s and TKVO infusion rates of 10, 20, and 40 mL/h. We determined TKVO efficacy using the stream of saline clearing the stasis region at the device tip and the shear stress acting on the vein. Results: At 10 mL/h TKVO rate, blood stasis occurs around the PIVC tip as saline is pulled into the faster-moving venous blood flow, creating the blood recirculation (stasis) zone at the device tip. When TKVO increases >20 mL/h, this stasis diminishes, and the likelihood of patency increases. Shear stress on the vein is negligible during TKVO but increases 10- to 19-fold when flushing the small and large veins investigated here. Conclusions: Low TKVO rates (10 mL/h) may not clear the PIVC tip and keep the device patent. Based on our simulations, we propose a TKVO rate of at least 20 mL/h could be used in practice; however, 30–40 mL/h appears most effective across different venous flow rates and peripheral vein sizes. However, this additional fluid load must be carefully considered based on the needs of each patient.

scholarly journals Effect of spontaneous breathing on umbilical venous blood flow and placental transfusion during delayed cord clamping in preterm lambs

2019 ◽  
Vol 105 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Emma Brouwer ◽  
Arjan B te Pas ◽  
Graeme R Polglase ◽  
Erin V McGillick ◽  
Stefan Böhringer ◽  
...  
Keyword(s):  
Blood Flow ◽  
Body Weight ◽  
Spontaneous Breathing ◽  
Venous Blood ◽  
Vena Cava ◽  
Venous Blood Flow ◽  
Delayed Cord Clamping ◽  
Venous Flow ◽  
Cord Clamping ◽  
Pregnant Sheep

IntroductionDuring delayed umbilical cord clamping, the factors underpinning placental transfusion remain unknown. We hypothesised that reductions in thoracic pressure during inspiration would enhance placental transfusion in spontaneously breathing preterm lambs.ObjectiveInvestigate the effect of spontaneous breathing on umbilical venous flow and body weight in preterm lambs.MethodsPregnant sheep were instrumented at 132–133 days gestational age to measure fetal common umbilical venous, pulmonary and cerebral blood flows as well as arterial and intrapleural (IP) pressures. At delivery, doxapram and caffeine were administered to promote breathing. Lamb body weights were measured continuously and breathing was assessed by IP pressure changes.ResultsIn 6 lambs, 491 out of 1117 breaths were analysed for change in body weight. Weight increased in 46.6% and decreased in 47.5% of breaths. An overall mean increase of 0.02±2.5 g per breath was calculated, and no net placental transfusion was observed prior to cord clamping (median difference in body weight 52.3 [−54.9–166.1] g, p=0.418). Umbilical venous (UV) flow transiently decreased with each inspiration, and in some cases ceased, before UV flow normalised during expiration. The reduction in UV flow was positively correlated with the standardised reduction in (IP) pressure, increasing by 109 mL/min for every SD reduction in IP pressure. Thus, the reduction in UV flow was closely related to inspiratory depth.ConclusionsSpontaneous breathing had no net effect on body weight in preterm lambs at birth. UV blood flow decreased as inspiratory effort increased, possibly due to constriction of the inferior vena cava caused by diaphragmatic contraction, as previously observed in human fetuses.

Midline skull tumors

2015 ◽  
Vol 42 (S1) ◽  
pp. S44-S45
Author(s):  
M Maleki
Keyword(s):  
Rare Case ◽  
Venous Return ◽  
Venous Blood ◽  
Subtotal Resection ◽  
Venous Blood Flow ◽  
Venous Flow ◽  
Posterior Portion ◽  
Sagittal Sinus ◽  
Skull Tumors ◽  
Visual Blurring

Introduction: Variety of tumors could involve the skull; however, very few may occur over the midline. Some may affect venous blood flow of superior sagittal sinus. Few challenging cases are presented Material: 1-Rare case of osteoblastoma over the torcula, (headache, visual symptoms, papilledema, VI nerve palsy). 2- Rare case of metastatic liposarcoma involving midsagital sinus, partially occluding it (headache and visual blurring). 3- A huge atypical (grade2) meningioma over the vertex Method: Case #1, the tumor over the venous confluences (torcula) was removed easily, without any complications. Complete resolution of symptoms Case #2, complete en-block resection of tumor, with sacrifice of mid-sagittal portion of sinus, without any neurological sequellae. Case #3, subtotal resection, followed by radiotherapy.Discussion &Conclusion: Anterior 3rd of sagital sinus could be sacrificed (if necessary), without major consequences. However, whenever mid or posterior portion of the sinus is involved, interruption of venous flow could pose very serious complications. Occasionally, chronic compression of sinus may force increasing collateral venous return, in which case one may attempt a complete resection of the lesion, with sacrifice of part of the sinus, as in our second case. In the region of torcula, however, one should be very careful not to damage it

Assessment Of Venous Function After Major Gynecological Surgery With Heparin-Dihydroergotamine In The Prophylaxis Of DVT

1981 ◽  
Author(s):  
S Kunz ◽  
O M Burth ◽  
E Zimmerer
Keyword(s):  
Doppler Ultrasonography ◽  
Varicose Veins ◽  
Synergistic Effects ◽  
Venous Blood ◽  
Haemodynamic Effect ◽  
Venous Blood Flow ◽  
Venous Flow ◽  
Venous Function ◽  
The Right ◽  
Clinical Conditions

Dihydroergotamine (DHE) has been shown to have synergistic effects with heparin in the prophylaxis of DVT. To assess the hemodynamic efficacy of DHE in clinical conditions, 72 patients undergoing hysterectomy were randomly allocated to three groups receiving heparin/DHE, heparin or acenocoumarol. Venous function was measured by occlusion plethysmography and doppler ultrasonography. Diagnosis of DVT by 125-I-fibrinogen test.Results: Doppler Ultrasonography: The velocity of venous flow in the left V. femoralis was lower than at the right side in all groups before hysterectomy. After surgery, a significant increase from 11.2 to 15.5 cm/sec in the heparin/DHE group could be demonstrated. Heparin and acenocoumarol patients showed a tendency to lower venous return. The differences were more marked in women with vaginal hysterectomy.Occlusion plethysmography: No differences in venous capacity before and after operation could be found in the heparin and acenocoumarol group. A significant reduction (16%) was measured in heparin/DHE treated patients. The maximal venous outflow also was significantly reduced in this group (18%). This difference also was found in patients with varicose veins.Conclusions: The data confirm that DHE increases the velocity of venous blood flow in the legs by constricting the capacitance vessels. This haemodynamic effect could be demonstrated in clinical conditions.

Incomplete Restoration of Homeostatic Shear Stress Within Arteriovenous Fistulae

2012 ◽  
Author(s):  
Patrick M. McGah ◽  
James J. Riley ◽  
Alberto Aliseda ◽  
Daniel F. Leotta ◽  
Kirk W. Beach
Keyword(s):  
Shear Stress ◽  
Peripheral Circulation ◽  
Shear Stresses ◽  
Dialysis Access ◽  
Venous Flow ◽  
Arteriovenous Fistulae ◽  
Flow Rates ◽  
Stage Renal Disease ◽  
End Stage ◽  
Low Shear

Arteriovenous fistulae are created surgically to provide an adequate access for dialysis in patients with End-Stage Renal Disease (ESRD). Producing an autogenous shunt linking an artery and a vein in the peripheral circulation bypasses the high resistance capillary bed in order to provide the necessary flow rates at sites easily accessible for dialysis. In successful fistulae, venous flow rates can easily exceed 1000 mL/min. It has long been recognized that the hemodynamics constitute the primary external influence on the remodeling process [1]; The high flow rate, together with the exposure of the venous tissue to the high arterial pressure, leads to a rapid process of wall remodeling that may end in a mature access or in failure. Recent hemodynamic simulations [2,3] have computed very high viscous wall shear stresses within fistulae; Stresses > 15Pa have been reported which are much greater than what is typically considered normal (i.e. homeostatic, ≈ 1Pa). Both sustained high shear and sustained low shear have been hypothesized to cause pathological venous remodeling (i.e. intimal hyperplasia) which causes stenoses and threatens fistula patency. The role of high vs. low shear stress in effecting patency remains unclear. Given the high failure rate of dialysis access sites (up to 50% require surgical revision within one year [4]), understanding the dynamics of blood flow within the fistula is a necessary step in understanding the remodeling, and ultimately, in improving clinical outcomes.

Do we still need compression bandages? Haemodynamic effects of compression stockings and bandages

2006 ◽  
Vol 21 (3) ◽  
pp. 132-138 ◽  
Author(s):  
H Partsch
Keyword(s):  
Flow Velocity ◽  
Venous Blood ◽  
Haemodynamic Effects ◽  
Venous Blood Flow ◽  
Compression Stockings ◽  
Venous Flow ◽  
Elastic Compression ◽  
Compression Bandages ◽  
Interface Pressures ◽  
Pumping Function

Objective: To compare haemodynamic data obtained with elastic compression stockings and inelastic compression material applied with different pressure ranges on the lower extremities. Methods: Haemodynamic effects of compression therapy were demonstrated by measuring venous flow velocity, venous volume, venous reflux and venous pumping function using radioisotopes, phlebography, water displacement volumetry, duplex, air plethysmography, foot volumetry and phlebodynamometry. Results: Light-compression stockings are able to increase venous blood flow velocity in the supine position and to prevent leg swelling after prolonged sitting and standing. In the upright position an interface pressure of more than 50 mmHg is needed for an intermittent occlusion of incompetent veins and for a reduction of ambulatory venous hypertension during walking. Such high interface pressures may rather be achieved by short-stretch, multilayer bandages than by an elastic stocking. Conclusion: Elastic compression stockings exerting interface pressures up to 40 mmHg are effective in preventing or reducing oedema. Multilayer compression bandages with a pressure over 40 mmHg additionally improve severely disturbed venous pumping function.

Mesenteric venous blood flow and the net absorption of glucose in sheep fed dried grass or ground maize-based diets

1984 ◽  
Vol 103 (3) ◽  
pp. 549-553 ◽  
Author(s):  
A. N. Janes ◽  
D. S. Parker ◽  
T. E. C. Weekes ◽  
D. G. Armstrong
Keyword(s):  
Blood Flow ◽  
Venous Blood ◽  
Live Weight ◽  
Glucose Absorption ◽  
Venous Blood Flow ◽  
Post Mortem ◽  
Mesenteric Blood Flow ◽  
Flow Rates ◽  
Mesenteric Vein ◽  
The Mean

SummaryA surgical procedure is described for placing a catheter in the mesenteric vein of sheep, such that blood draining the reticulo-rumen is not sampled. This catheter, together withothers in the mesenteric vein and carotid artery, was used to determine mesenteric blood flow and the net absorption of glucose in five sheep fed both dried grass and ground maize-based diets. The mean (± S.E.) mesenteric blood flow rates were 33 ±0·9 and 37 ± 5·7ml/min/kg live weight when fed the dried grass and maize-based diets respectively. These flow rates, together with the small venousarterial differences in plasma volatile fattyacid concentrations observed, indicated that the mesenteric catheter did not sample blood draining the reticulo-rumen in the conscious, fed animal. Further confirmation was provided by subsequent post-mortem examinations of the catheters. When fed the dried-grass diet, a significant net absorption of glucose could not be detected. However, when fed the maize-based diet a net glucose absorption of 19·3 ± 0·75 mmol/h was observed.

Venous Blood Flow in the Dog Leg Following Cold Injury

1957 ◽  
Vol 188 (3) ◽  
pp. 461-469 ◽  
Author(s):  
Esther Hardenbergh ◽  
Paul G. Bamberg
Keyword(s):  
Blood Flow ◽  
Venous Blood ◽  
Control Flow ◽  
Tissue Temperature ◽  
Venous Blood Flow ◽  
Vasoactive Drugs ◽  
Solid Carbon Dioxide ◽  
Venous Outflow ◽  
Flow Rates ◽  
Exposure To Cold

In an attempt to determine the nature of the circulatory changes which occur in tissues injured by exposure to cold, the rate of venous outflow was studied in the dog's hind leg exposed to freezing temperatures. Before exposure to cold, control flow rates were determined, and changes in flow were measured following the injection of vasoactive drugs. Measurements were continued during a 30-minute immersion of the leg in an alcohol-solid carbon dioxide bath (app. –30°C), and then for several hours after the leg had been removed and thawed. Control blood flow rates were found to vary considerably from animal to animal (20 cc/min. to 90 cc/min.) but varied little in each individual. During exposure to cold, in most of the experiments, the legs froze: flow decreased almost to zero, and the temperature in the leg fell well below 0°C. In some experiments, however, the legs did not freeze: flow remained high throughout exposure, and tissue temperature remained above 0°C. In response to the injection of vasoactive drugs, the control venous outflow showed: a) a decrease after intravenous epinephrine; b) a decrease after intra-arterial epinephrine into the experimental leg; c) a transient increase after intra-arterial acetylcholine into the experimental leg. After exposure to cold, the legs which did not freeze still showed these reactions. However, in the legs which were frozen the reactions to intra-arterially injected drugs were very much diminished, and the flow was increased instead of decreased when epinephrine was intravenously administered.

scholarly journals КОМПРЕСІЙНА АСФІКСІЯ

2019 ◽  
Vol 1 (11(41)) ◽  
pp. 26-31
Author(s):  
Хоботова Наталія Володимирівна ◽  
Єхалов Василій Вталійович
Keyword(s):  
Venous Blood ◽  
Intrathoracic Pressure ◽  
Shoulder Girdle ◽  
External Pressure ◽  
The Body ◽  
Whole Body ◽  
Venous Blood Flow ◽  
Venous Flow ◽  
Septic Complications ◽  
The Face

Compression asphyxia is a type of mechanical asphyxia when breathing stops with external pressure on the body, which leads to the absence of respiratory movements and disrupts venous return from the head. With a strong compression of the chest, a reflex spasm of the glottis occurs, which contributes to an increase in intrathoracic pressure, reverse venous blood flow and an obstruction of venous flow to the heart occur. A sharp increase in intracranial pressure and venous congestive congestion / hemorrhage deepen central respiratory failure. Mild degree: mental agitation; puffy face, slight cyanosis; individual conjunctival petechiae; tachypnea. Medium degree: light or heavy stunning, lost orientation; the face is puffy, cyanotic; swelling of the cervical veins, acrocyanosis; multiple petechiae that spread across the face, neck, conjunctiva of the eyes, inspiratory dyspnea, visual impairment. Severe degree: stupor or coma, sharp cyanosis of the whole body, exophthalmos; swelling of the face, neck and shoulder girdle, arms, multiple petechiae of the face, neck, arms, legs, conjunctiva of the eyes, swelling of the cervical veins, cyanosis and edema of the upper half of the body; superficial breathing, frequent, in the absence of treatment passes to agonal and apnea. Intensive care includes analgesia, oxygenation or mechanical ventilation, anticonvulsant, dehydration and decongestant therapy, prevention of acute kidney damage, DIC, septic complications, and treatment of posthypoxic encephalopathy.

scholarly journals Arterio-Venous Branchial Blood Flow in the Atlantic Cod Gadus Morhua

1992 ◽  
Vol 165 (1) ◽  
pp. 73-84 ◽  
Author(s):  
LENA SUNDIN ◽  
STEFAN NILSSON
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Atlantic Cod ◽  
Vascular System ◽  
Venous Blood ◽  
Venous Blood Flow ◽  
Venous Flow ◽  
Flow Measurements ◽  
Vasomotor Function

We have estimated the branchial venous blood flow in the Atlantic cod by direct single-crystal Doppler blood flow measurements in vivo. In the undisturbed animal, this flow amounts to 1.7 ml min−1 kg−1, which corresponds to about 8 % of the cardiac output. Studies of both an isolated perfused gill apparatus in situ and simultaneous measurements of cardiac output and branchial venous flow in vivo were made to assess the effects of some putative vasoregulatory substances. Adrenaline dilates the arterio-arterial pathway and constricts the arterio-venous pathway, thus decreasing branchial venous drainage. 5-Hydroxytryptamine (5-HT), in contrast, produced marked vasoconstriction in the arterio-arterial pathway of the branchial vasculature, increasing the branchial venous blood flow. Cholecystokinin-8 (CCK-8) and caerulein produced similar cardiovascular effects, with marked constriction of both arterio-arterial and arterio-venous pathways. The study demonstrates the ability of the vascular system of the gills to regulate the distribution of branchial blood flow, and summarizes the vasomotor effects of some substances with possible vasomotor function in the cod gills.

scholarly journals Transjugular Intrahepatic Portosystemic Shunt for Maintenance of Portal Venous Patency in Liver Transplant Candidates

2013 ◽  
Vol 3 ◽  
pp. 29 ◽  
Author(s):  
Ron Charles Gaba ◽  
Ahmad Parvinian
Keyword(s):  
Liver Transplant ◽  
Transjugular Intrahepatic Portosystemic Shunt ◽  
Venous Blood ◽  
Portosystemic Shunt ◽  
Venous Blood Flow ◽  
Venous Flow ◽  
Vein Thrombosis ◽  
Surgical Complexity ◽  
Intrahepatic Portosystemic Shunt ◽  
Transplant Candidates

Maintenance of portal venous patency is vital to liver transplant candidates, as the presence of portal vein thrombosis (PVT) adversely impacts clinical outcomes by increasing surgical complexity and decreasing postoperative survival. By enhancing portal venous blood flow, transjugular intrahepatic portosystemic shunt (TIPS) creation may enable clearance of PVT and preservation of portal venous patency in cirrhotic patients. Herein, we describe four cases in which TIPS produced and sustained an open portal venous system in liver transplant candidates with partial PVT. All patients demonstrated rapid and effective flow-enabled clearance of clot and intermediate to long-term preservation of portal venous flow. On this basis, we propose that maintenance of portal venous patency in liver transplant candidates with partial PVT represents a developing indication for TIPS.

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