Power injection of intravenous contrast material through central venous catheters for CT: in vitro evaluation

Optimizing Identification of Power Injectable Ports on the Scout Images for Multidetector Computed Tomography Procedures

OBJECTIVE

The objective of this study was to assess the impact of tube voltage and image display on the identification of power ports features on anterior-posterior scout images to inform optimal workflow for multidetector computed tomography (MDCT) examinations.

MATERIALS AND METHODS

Four ports, representing variable material composition (titanium/silicone), shapes, and computed tomography (CT) markings, were imaged on an adult anthropomorphic chest phantom using a dual-source MDCT at variable peak tube voltages (80, 100, 120, 150, and Sn150 kVp). Images were reviewed at variable image display setting by 5 blinded readers to assess port features of material composition, shape, and text markings as well as overall preferred image quality.

RESULTS

Material composition was correctly identified for all ports by all readers across all kilovoltage-peak settings. The identification by shape was more reliable than CT markers for all but one of the ports. CT marker identification was up to 80% for titanium ports at window level settings optimized for metal (window width, 200; window center, -150) and at a soft tissue setting (window width, 400; window center, 40) for silicone ports. Interreader agreement for best image quality per kilovoltage-peak setting was moderate to substantial for 3 ports (k = 0.5-0.62) but only fair for 1 port (k = 0.27). The highest overall rank for image quality was given unanimously to Sn150 kVp for imaging titanium ports and 100 kVp for silicone ports.

CONCLUSIONS

Power port identification on MDCT scout images can be optimized with modification of MDCT scout acquisition and display settings based on the main port material.

Power contrast injections through a totally implantable venous power port: A retrospective multicenter study

Objectives

To evaluate the feasibility and safety of power injection of contrast media through totally implantable venous power ports during computed tomography scans in oncologic patients.

Methods

The study population consisted of 417 patients who underwent computed tomography scan through a totally implantable venous power port. Clinical data were examined. Logistic regression analysis was used to assess the associations between clinical covariables and computed tomography scan failure.

Results

Successful computed tomography scans were achieved in 534 of 540 examinations (98.9%). Logistic regression analysis showed that contrast media above a 350 concentration was significantly associated with computed tomography scan failure (95% confidence interval: 1.01–1.13, p = 0.012). No major complications were noted.

Conclusions

Power injection of contrast media through a totally implantable venous power port for computed tomography examination is feasible and safe. This procedure provides an acceptable alternative in oncologic patients with inadequate peripheral intravenous access when computed tomography examination with contrast enhancement is needed.

Nephrogenic systemic fibrosis: A survey of the use of gadolinium-based contrast agents in Ghana

INTRODUCTION

The aim of this study is to identify current practice of administration of gadolinium-based contrast agents (GBCAs) in Ghana.

METHOD

A total of 13 MRI (magnetic resonance imaging) facilities were sent a survey questionnaire to request information on their current practice with the use of GBCAs.

RESULTS

Gadodiamide, a high risk GBCA accounted for 67% of first line agents. 5 (42%) had a departmental protocol on the administration of GBCAs with regards to its association with nephrogenic systemic fibrosis (NSF). Of the 8 that use gadodiamide, 3 check kidney function in all patients, 2 check in selected patients, and 3 do not check at all. All 3 that screen all patients do not use contrast if the patient has an eGFR (estimated glomerular filtration rate) of 30-59 ml/min, 1 considers other modality; and if the patient has an eGFR of <30 ml/min, 2 do not use contrast but consider other modality, however 1 continues with the high risk agent.

CONCLUSION

Gadodiamide is widely used, with varied practice in screening for renal function, and risk factors associated with NSF. Current evidence shows that it is advisable to administer macrocyclic agents in patients with compromised renal function. It is also imperative to establish local guidelines in line with international guidelines in order to minimize the incidence of NSF.

Injection of gadolinium contrast through pediatric central venous catheters: a safety study

BACKGROUND

Catheter rupture during CT angiography has prompted policies prohibiting the use of electronic injectors with peripherally inserted central venous catheters (PICCs) not only for CT but also for MRI. Consequently, many institutions mandate hand injection for MR angiography, limiting precision of infusion rates and durations of delivery.

OBJECTIVE

To determine whether electronic injection of gadolinium-based contrast media through a range of small-caliber, single-lumen PICCs would be safe without risk of catheter rupture over the range of clinical protocols and determine whether programmed flow rates and volumes were realized when using PICCs for contrast delivery.

MATERIALS AND METHODS

Experiments were performed and recorded using the Medrad Spectris Solaris EP MR Injection System. PICC sizes, contrast media and flow rates were based on common institutional protocols.

RESULTS

No catheters were damaged during any experiments. Mean difference between programmed and delivered volume was 0.07 ± 0.10 mL for all experiments. Reduced flow rates and prolonged injection durations were observed when the injector's pressure-limiting algorithm was triggered, only in protocols outside the clinical range.

CONCLUSION

PICCs commonly used in children can withstand in vitro power injection of gadolinium-based contrast media at protocols significantly above clinical levels.

Power Injection of Iodinated Intravenous Contrast Material through Acute and Chronic Hemodialysis Catheters

Purpose

End-stage renal disease patients with hemodialysis catheters in need of contrast enhanced imaging studies often have limited peripheral venous access. In this study we aimed to determine pressures generated in hemodialysis catheters during power injection of computed tomography (CT) contrast media.

Methods

Three different chronic hemodialysis catheters and two acute hemodialysis catheters were included in this study. All catheters were evaluated in vitro. A total volume of 120 cc of CT contrast material was injected at rate of 10 cc/s using a power injector. The catheters were connected to the power injector using a standard connecting tubing. Pressures were simultaneously measured in the power injector as well as in the hemodialysis catheters.

Results

The maximal measured pressures during injection in the power injector averaged 338 PSI (SD ± 8.7 PSI). The maximal measured pressure in the dialysis catheters ranged between 9.17 and 21.2 PSI. Pressures averaged 14.02 PSI (SD ± 3.34 PSI). The average pressure in the power injector was over 23 times higher than the pressure recorded at the hemodialysis catheter. None of the catheters ruptured or deformed during testing.

Conclusions

Pressures measured in hemodialysis catheters during power injection are lower than currently believed and markedly lower than the pressures recorded in the power injector. Standard hemodialysis catheters are likely to be amenable to power contrast injection in hemodialysis patients who have limited venous access. In vivo studies are necessary to confirm these findings.

Gavecelt Consensus Statement on the Correct use of Totally Implantable Venous Access Devices for Diagnostic Radiology Procedures

The use of totally implantable venous access devices in radiology may be associated with complications such as occlusion of the system (because of the high density of some contrast), infection (if the port is not handled in aseptic conditions, using proper barrier protections), and mechanical complications due to the high-pressure administration of contrast by automatic injectors (so-called power injector), including extravasation of contrast media into the soft tissues, subintimal venous or myocardial injection, or serious damage to the device itself (breakage of the external connections, dislocation of the non-coring needle, or breakage of the catheter).

The last problem – i.e., the damage of the device from a power injection – is not an unjustified fear, but a reality. A warning by the US Food and Drug Administration of July 2004 reports around 250 complications of this kind, referring to both port and central venous catheters and peripherally inserted central catheter systems, which occurred over a period of several years; in all cases, the damage occurred during the injection of contrast material by means of power injectors for computed tomography or magnetic resonance imaging procedures.

Though the risk associated with the use of ports in radiodiagnostics is thus clear, it has been suggested that administration of the contrast material via the port may have some advantage in terms of image quality, increased comfort for the patient, and maybe more accurate reproducibility of the patient's own follow-up exams. This contention needs to be supported by evidence.

Also, since many cancer patients who need frequent computed tomography studies already have totally implantable systems, it would seem reasonable to try to define how and when such systems may safely be used.

The purpose of this consensus statement is to define recommendations based on the best available evidence, for the safe use of implantable ports in radiodiagnostics.

The use of central venous catheters for intravenous contrast injection for CT examinations

The use of intravenous (i.v.) contrast media in CT examinations is often of great value in improving diagnostic accuracy. The preferable route of administration is via a peripheral i.v. cannula, with powered injectors allowing reliable delivery of rapid flow rates. However, many patients with a pre-existing central venous access device may have difficult peripheral access and there is a temptation to use the central device for delivery of contrast media. This review summarises the available evidence for the safe and effective use of these devices to assist the radiologist in balancing the relative risks and benefits of their use for contrast medium injection.

Feasibility of power contrast injections and bolus triggering during CT scans in oncologic patients with totally implantable venous access ports of the forearm

BACKGROUND

Conventional totally implantable venous access ports (TIVAPs) are not approved for power contrast injections but often remain the only venous access site in oncologic patients. Therefore, these devices can play an important role if patients with a TIVAP are scheduled for a contrast-enhanced computed tomography (ceCT) as vascular access may become more difficult during the course of chemotherapy.

PURPOSE

To evaluate the feasibility and safety of power injections in conventional TIVAPs in the forearm and to analyze the feasibility of bolus triggering during CT scans.

MATERIAL AND METHODS

In this retrospective study we analyzed 177 power injections in 141 patients with TIVAPs in the forearm. Between October 2008 and March 2010 all patients underwent power injections (1.5 mL/s, 150 psi) via the TIVAP for ceCT because conventional vascular access via a peripheral vein had failed. Adequate functioning and catheter's tip location after injection were evaluated. Peak injection pressure and attenuation levels of aorta, liver and spleen were analyzed and compared with results of 50 patients who were injected via classical peripheral cannulas (3 mL/s, 300 psi). Feasibility of automatic scan initiation was evaluated. In vitro the port was stressed with 5 mL/s (300 psi).

RESULTS

One TIVAP showed tip dislocation with catheter rupture. Three (2.1%) devices were explanted owing to assumed infection within 4 weeks after the injection. Mean injection pressure was 121.9 +/-24.1 psi. Triggering with automatic scan initiation succeeded in 13/44 (29.6%) scans. Injection via classical cannulas resulted in significantly higher enhancement (p < 0.05). In vitro the port system tolerated flow rates of up to 5 mL/s, injection pressures of up to 338 psi.

CONCLUSION

Power injection is a safe alternative for patients with TIVAPs in the forearm if classic vascular access ultimately fails. Triggering was successful in one-third of the attempts. Image quality in the arterial phase scan may be hampered. In vitro results suggest that the device tolerates even higher flow rates.

Current imaging of prenatally diagnosed congenital lung lesions

Congenital lung lesions refer to a spectrum of pulmonary developmental anomalies including, but not limited to, bronchial atresia, congenital pulmonary airway malformation (formerly known as congenital cystic adenomatoid malformation) and bronchopulmonary sequestration. These anomalies comprise about 90% of the anomalies seen in clinical practice. The advent of prenatal sonography and, more recently, fetal magnetic resonance imaging has changed our understanding and practice in the evaluation of congenital lung lesions. Postnatal imaging using low-dose computed tomography angiography (CTA) is extremely useful as it may provide information essential for differential diagnosis by allowing multiplanar reconstructions of the airway, lung parenchyma, and vasculature. The use of iodine in CTA permits the application of low-dose radiation protocols in these young patients. The purpose of this article is to emphasize the technical factors that may optimize low-dose CTA evaluation of these lesions. We also provide a description of prenatal imaging findings and helpful diagnostic clues that may be useful for the characterization of the most commonly encountered prenatally diagnosed pulmonary developmental anomalies.

Peripheral intravenous power injection of iodinated contrast media: the impact of temperature on maximum injection pressures at different cannula sizes

RATIONALE AND OBJECTIVES

Modern computed tomographic scanners and examination protocols often require high injection rates of iodinated contrast media (CM). The purpose of this study was to investigate the maximum injection pressures (MIPs) with different CM at different temperatures in the most common intravenous cannula (IVC) sizes.

MATERIALS AND METHODS

Three IVC sizes, 22, 20, and 18 gauge, were evaluated. All examinations were performed with a pressure-limited (300 psi) power injector. The MIPs of three different CM (Solutrast 300, Imeron 350, and Imeron 400) were measured at room temperature (20 degrees C) and at 37 degrees C using increasing flow rates (1-9 mL/s). The intactness of the IVCs was checked after injection.

RESULTS

Heating the CM led to reductions in injection pressures (P < .001). Using constant flow rates, the difference in MIP between 20-gauge and 22-gauge IVCs was higher than that between 20-gauge and 18-gauge IVCs. By heating the CM, the manufacturer's suggested operating pressure limit was exceeded at higher flow rates, such as with an 18-gauge cannula at 8 mL/s instead of 6 mL/s using warmed iomeprol 400. Even with pressures of up to 159.7 psi, none of the IVCs ruptured.

CONCLUSIONS

Heating of CM effectively reduces MIPs using power injection in common IVCs. Although the manufacturer's suggested MIP was exceeded at higher flow rates, safe CM injection seems to be possible even in small cannulas using power injection. The compilation of the obtained data is meant to serve as guidance for future decisions on parameters of the power injection of iodinated CM.

Preparation and characterization of gelatin sponge millispheres injectable through microcatheters

Objective

Millimeter size gelatin sponges are commonly used as an embolic agent for transcatheter arterial embolization (TAE). However the preparation of the fragments is troublesome and carries a risk of contamination. The purpose of this study was to develop gelatin sponge millispheres (GSMs), a convenient and reliable agent, and characterize them in vitro.

Method

The size of GSMs was controlled by modifying the previously reported method to include the use of caprylic triglyceride and isopropanol. Analytical and microbiological tests were conducted to detect impurities (caprylic triglyceride, isopropanol, endotoxins, bacteria, and fungus). The effects of syringe volume (1.0 to 5.0 ml) and contrast media viscosity (1.6 to 13.6 mPa * s) on the in vitro injectability of GSMs through microcatheters of various inner diameters (ID) (0. 43 to 0.53 mm) were examined via in-line pressure monitoring.

Results

The GSMs were found to be water-insoluble particles containing interconnected pores. The short and long diameters of the GSMs were 1.82 ± 0.2 mm and 2.37 ± 0.3 mm, respectively. The results of tests for impurities indicated that GSMs have the general properties necessary for medical devices. The GSMs were successfully injected without clogging through a microcatheter (ID: 0.53 mm) attached to a 1.0 or 2.5 ml syringe.

Conclusion

GSMs have the basic properties and injectability necessary to be considered reliable biomaterials (eg, embolic agents).

A simple method to estimate the optimum iodine concentration of contrast material through microcatheters: hydrodynamic calculation with spreadsheet software

It is important to increase the iodine delivery rate (I), that is the iodine concentration of the contrast material (C) x the flow rate of the contrast material (Q), through microcatheters to obtain arteriograms of the highest contrast. It is known that C is an important factor that influences I. The purpose of this study is to establish a method of hydrodynamic calculation of the optimum iodine concentration (i.e., the iodine concentration at which I becomes maximum) of the contrast material and its flow rate through commercially available microcatheters. Iopamidol, ioversol and iohexol of ten iodine concentrations were used. Iodine delivery rates (I meas) of each contrast material through ten microcatheters were measured. The calculated iodine delivery rate (I cal) and calculated optimum iodine concentration (calculated C opt) were obtained with spreadsheet software. The agreement between I cal and I meas was studied by correlation and logarithmic Bland-Altman analyses. The value of the calculated C opt was within the optimum range of iodine concentrations (i.e. the range of iodine concentrations at which I meas becomes 90% or more of the maximum) in all cases. A good correlation between I cal and I meas (I cal = 1.08 I meas, r = 0.99) was observed. Logarithmic Bland-Altman analysis showed that the 95% confidence interval of I cal/I meas was between 0.82 and 1.29. In conclusion, hydrodynamic calculation with spreadsheet software is an accurate, generally applicable and cost-saving method to estimate the value of the optimum iodine concentration and its flow rate through microcatheters.

Injection rate threshold of triple-lumen central venous catheters: an in vitro study

RATIONALE AND OBJECTIVES

Computed tomographic angiography (CTA) requires the rapid injection of contrast media ideally through an 18-gauge intravenous line in the antecubital fossa. Patients with CVCs undergoing CTA, however, are typically injected at low rates for two reasons: the potential for catheter failure and because of the lack of manufacturer recommendations for high injection rates typically used during CTA. The purpose of the study is to measure the injection rate thresholds of CVC. The results suggest that CVC can be used at high injection rates that are now typically used with peripheral intravenous catheters during CTA.

MATERIALS AND METHODS

We used 16-cm-long catheters and 20-cm-long catheters in six groups (n = 5 for each catheter length). After the catheters were placed into a water bath, each group was injected at 5, 10, 15, 20, 25, and 30 ml/sec. New contrast, pressure tubing, and catheters were used for each test.

RESULTS

No catheter ruptures were encountered during the experiment, but there was one episode of power injector tubing rupture during the injection of a 16-cm catheter at an injection rate of 30 ml/sec.

CONCLUSION

No catheter failures were demonstrated in this study using injection rates well above those used in conventional CTA. Power injector tubing failure was demonstrated at an injection rate of 30 ml/sec, which generated mean pressures in the 16-cm catheters of 920 psi (tubing rating per manufacturer is 300 psi). This study demonstrated no catheter or injector tubing failure at injection rates of 5 to 25 ml/sec.

Safety and Efficacy of Pressure-Limited Power Injection of Iodinated Contrast Medium Through Central Lines in Children

OBJECTIVE

The purpose of this study was to evaluate the safety and efficacy of pressure-limited power injection of contrast medium through central lines for pediatric body CT examinations.

SUBJECTS AND METHODS

All patients with a central line who were referred for body CT examinations requiring an i.v. contrast agent were prospectively evaluated. The power injector was pressure limited to 25 psi (172 kPa). A standard dose of 2 mL/kg of iodinated contrast medium was power-injected through the central line. Two pediatric radiologists scored all examinations on a scale of 1 (poor) to 5 (superior) for adequacy of contrast enhancement. Regression and receiver operating characteristic analyses were performed.

RESULTS

The subjects were 63 patients 0.3-22 years old. Nineteen of these patients had tunneled lines, 18 had ports, and 26 had peripherally inserted central catheters. There were no complications related to power injection. Regression analysis showed a significant association between patient weight and contrast enhancement adequacy score (p < 0.001), higher patient weights yielding lower contrast enhancement adequacy scores. Receiver operating characteristic analysis showed a weight cutoff of 30 kg as a reasonable predictor of adequacy of contrast enhancement. For patients weighing 30 kg or more, the average contrast enhancement score was 2.4 (suboptimal to adequate). For patients weighing less than 30 kg, the average contrast enhancement score was 3.4 (adequate to good).

CONCLUSION

Pressure-limited power injection through central lines in children is safe. The contrast enhancement obtained with 25 psi (172 kPa) pressure-limited injection is acceptable only for patients who weigh less than 30 kg.

Central line pump infusion and large volume mediastinal contrast extravasation in CT

The use of multidetector CT scanners for CT angiography requires rapid injection of radiographic contrast media. Central venous catheters are now widely used for this purpose. Several complications may occur while using central venous access for rapid, large volume contrast injection such as catheter rupture and contrast extravasation. We describe a case in which inadvertent malposition of a central venous catheter led to a high volume extravasation of contrast in the mediastinum in a trauma patient.

Power Injection of Microcatheters: An In Vitro Comparison

PURPOSE

To determine the tolerance of 0.021-inch and 0.027-inch microcatheters to power injection in an in vitro flow model.

MATERIALS AND METHODS

Twenty-four microcatheters (0.021-inch, n = 13; 0.027-inch, n = 11) were injected with iothalamate meglumine through a flow model with use of a power injector and high-pressure tubing. Catheters used included Rebar (0.021-inch, n = 4; 0.027-inch, n = 4), Transit (0.021-inch, n = 3; 0.027-inch, n = 3), Renegade (0.021-inch, n = 4; 0.027-inch, n = 4), and Renegade STC-18 (0.021-inch, n = 2) models. Through the 0.021-inch microcatheters, 5-second injections were performed at an initial rate of 0.7 mL/sec. Injection rates were increased by 0.5 mL/sec and the process was repeated until the pressure approached 1,000 psi or catheter breakage occurred. A similar process was repeated for the 0.027-inch catheters starting at a rate of 3.4 mL/sec.

RESULTS

The 0.021-inch catheters were injected 303 times and the 0.027-inch catheters were injected 210 times. Three catheter failures occurred, with all breaks occurring at pressures greater than manufacturer recommendations. The 0.027-inch catheters as a group tolerated significantly higher injection rates than the 0.021-inch catheters. Of the 0.021-inch catheters, the STC-18 also provided superior maximum flow and volume compared with the Renegade catheter. The Rebar catheter tolerated significantly lower maximum injection rates and volumes than the other 0.027-inch catheters.

CONCLUSIONS

The majority of microcatheters can be power-injected in vitro at pressures far greater than manufacturer recommendations. When fractures occur, they are near the hub of the catheter. Significantly greater rates of injection are possible through 0.027-inch catheters.

Safety and Feasibility of Using a Central Venous Catheter for Rapid Contrast Injection Rates

OBJECTIVE

Our aim was to determine the safety and feasibility of using a central venous catheter for rapid contrast injections during CT.

MATERIALS AND METHODS

An in vitro experiment was performed using a 7-French Arrow-Howes multilumen central venous catheter. Each catheter port was tested by varying contrast agent flow rates delivered by a power injector. Contrast media specifications were kept similar to routine clinical practice. The in vivo experiment included 104 cases in which rapid contrast injections, 3.0-5.0 mL/sec, were delivered through a central venous catheter for dynamic CT examinations. Patient monitoring for early complications of contrast extravasation, cardiac arrhythmia, and allergic reactions was performed. Contrast injections were monitored for pressure limitation, automatic flow-rate adjustment, and catheter injury. Chart review was performed for delayed complications of mediastinal hematoma, infection, or catheter malfunction.

RESULTS

During the in vitro experiment, all desired flow rates, 3.0-9.9 mL/sec, could be delivered through the central venous catheter with no catheter injury. No immediate or early patient or catheter complications were observed during the in vivo experiment. Follow-up evaluation revealed that 18 blood cultures and one catheter culture were positive for bacterial growth. In a subgroup of 43 patients, five contrast injections were pressure-limited by the power injector, and only one had the flow rate automatically adjusted to 3.6 mL/sec from 4.0 mL/sec.

CONCLUSION

Rapid contrast injection rates, at 3.0-5.0 mL/sec, through the Arrow-Howes multilumen central venous catheter are feasible and safe in the clinical setting. However, a strict protocol should be followed to avoid possible serious complications.

Maximal Flow Rates Possible during Power Injection through Currently Available PICCs: An In Vitro Study

PURPOSE

Currently available 4-F and 5-F peripherally inserted central catheters (PICCs) were investigated to evaluate their possible application for contrast medium injection using power injectors. The study was performed using an in vitro model to demonstrate the feasibility of using PICCs for contrast-enhanced diagnostic studies.

MATERIALS AND METHODS

An evaluation of 24 catheter versions consisting of 4-F single-lumen and 5-F dual-lumen PICCs from 13 different manufacturers was conducted. Six of the catheter types were silicone and 18 catheter types were polyurethane. Ten catheters of each type were evaluated with five at full length and five trimmed to 40 cm. With use of a silicone-based simulated SVC model, the catheters were infused with 50 mL of intravenous contrast medium at each flow rate increment. Catheters were tested at increasing flow rates from 0.5 to 5 mL/sec in 0.5-mL/sec increments using a Percupump CT injector. Catheters that failed to rupture were then infused at 1-mL/sec increments at flow rates from 5 to 17 mL/sec using a MedRad Mark V power injector. Tolerated and bursting pressures were recorded as well as the location of the catheter rupture.

RESULTS

Polyurethane catheters ruptured at flow rates between 4 and 15.4 mL/sec, with one catheter not rupturing at the maximal flow rate (17 mL/sec). Silicone catheters ruptured at flow rates between 0.5 to 3.5 mL/sec. Average rupture locations by type and length were at the extension leg/hub connection area on five of the PICCs, on the extension legs on 21 of the PICCs, on the catheter/hub connection on four PICCs, and on the proximal catheter on 16 of the PICCs.

CONCLUSION

The low burst rates at which all silicone catheters ruptured suggest that those catheters are not able to withstand typical flow rates used for CT arteriography. Conversely, although there is a wide range of discrepancy in the polyurethane catheter burst pressures, many polyurethane catheters can tolerate relatively high flow rates without rupture. This suggests that they may be safely used for CT arteriography with appropriate precautions and protocols in place.

Assessing the adequacy of peripherally inserted central catheters for power injection of intravenous contrast agents for CT

PURPOSE

The purpose of this work was to determine the tolerance of silicone peripherally inserted central catheters (PICCs) of different sizes and lengths to power injection of contrast materials at flow rates suitable for CT studies.

METHOD

Fifty silicone PICCs in three single-lumen sizes (3 to 5F) and two double-lumen sizes (6 and 7F) were cut to two lengths (35 and 45 cm), and a uniform volume of 74% ioversol was injected into each at increasing rates of flow by a power injector. The flow rate, volume, and peak pressure were recorded for each injection.

RESULTS

The respective tolerated flows for the 35 and 45 cm PICCs were 0.65 ml/s at 125 psi and 0.56 ml/s at 125 psi for the 3F catheters, 1.58 ml/s at 150 psi and 1.04 ml/s at 150 psi for the 4F catheters, 4.20 ml/s at 200 psi and 3.02 ml/s at 170 psi for the 5F catheters, 1.50 ml/s at 145 psi and 0.88 ml/s at 150 psi for the 6F catheters, and 9.52 ml/s at 350 psi and 8.78 ml/s at 330 psi for the 7F catheters.

CONCLUSION

The 3F catheters were unsuitable for power injection for CT studies because they could not accommodate adequate flow rates. The 4F single-lumen and 6F double-lumen catheters withstood flow rates that were marginally adequate for CT studies. The 5F single-lumen and 7F double-lumen PICCs tolerated peak flows and pressures well within the range necessary to allow power injection of contrast materials for CT studies. For each size of PICC, the 35 cm length withstood higher flow rates than the 45 cm length before failure.

Power injection of contrast media using central venous catheters: feasibility, safety, and efficacy

OBJECTIVE

This study evaluates the feasibility, safety, and efficacy of power-injecting IV contrast media through central venous catheters for CT examinations.

SUBJECTS AND METHODS

Two hundred ninety-five CT examinations were performed during an 18-month period in 225 patients with indwelling central venous catheters. Patients were randomized to power injection either through peripheral IV catheter or through central venous catheter. Feasibility was defined as the percentage of patients with contrast material injected successfully through the randomized access route. Safety was evaluated by comparing patients with complications. Efficacy was evaluated by comparing contrast enhancement of the thoracic aorta, pulmonary artery, abdominal aorta, and liver.

RESULTS

Two hundred nine patients had randomization data recorded. One hundred three (94%) of 109 patients were successfully injected through their indwelling catheter compared with 42 (42%) of 100 through a peripherally placed IV catheter (p < 0.001). After reassignment for unsuccessful access, 174 patients underwent central venous catheter injection, and 51, peripheral IV catheter injection. No statistically significant difference was noted in the complications between the central venous catheter and peripheral IV catheter groups. Enhancement was greater in the thoracic aorta, pulmonary artery, and liver for the peripheral IV catheter group (p < 0.03).

CONCLUSION

Power injection of contrast media through central venous catheters for CT examinations is feasible and safe when set hospital guidelines and injection protocols are followed. This technique provides an acceptable alternative in patients without adequate peripheral IV access when bolus contrast enhancement is desired.

Power injection of peripherally inserted central catheters

PURPOSE

To study the tolerance of peripherally inserted central catheters (PICCs) of varying sizes and materials to power injection of radiographic contrast agents.

MATERIALS AND METHODS

Eight different models of silicone and five different models of polyurethane single-lumen PICCs were injected with increasing rates of iothalamate 60% with use of a power injector. Tolerated and bursting rates and pressures were recorded.

RESULTS

There was a wide range of tolerated rates and pressures, depending on the inner and outer diameters of the catheters and on the catheter material. Silicone PICCs tolerated rates between 0.4 and 7.0 mL/sec and polyurethane PICCs tolerated rates between 0.6 and 10.2 mL/sec, depending on the specific catheter. The 5-F silicone PICCs and the 4-F and 5-F polyurethane PICCs tested all tolerated rates greater than 4 mL/sec. Silicone catheters tolerated pressures between 107 and 184 psi, and polyurethane catheters tolerated pressures between 160 and 314 psi.

CONCLUSIONS

Larger single-lumen silicone and polyurethane PICCs may be suitable for power injection of contrast agents.