Experimental approach to prevention of catheter-related central venous thrombosis

Improved visualization of peripherally inserted central catheters on chest radiographs of neonates using fractional multiscale image processing

BACKGROUND

Peripherally inserted central catheters (PICCs) provide secure intravenous access for the delivery of life-sustaining medications and nutrition. They are commonly used in pediatrics. Confirmation of correct central catheter tip position is crucial. Verification is usually done by a radiograph. The aim of this study is to evaluate the ability of Fractional Multiscale image Processing (FMP) to detect PICC tips on the digital chest radiographs of neonates.

METHODS

A total of 94 radiographs of 47 patients were included in the study. 29 patients were male, 18 were female. The mean age of all examined children was 9.2 days (range 0-99 days). In total, six readers (two radiologists, two residents in radiology, one last year medical student, one neonatologist) evaluated 94 unprocessed and catheter-enhanced radiographs using a 5-point Likert scale (1 = poor catheter tip visualization, 5 = excellent catheter tip visualization). Additionally, the two radiologists evaluated the diagnostic confidence for chest pathologies using a 5-point Likert scale (1 = poor diagnostic confidence, 5 = excellent diagnostic confidence). Radiographs were evaluated on a dedicated workstation.

RESULTS

In all cases, the catheter-enhanced radiograph rated higher than (n = 471), or equal (n = 93) to, the unprocessed radiograph when visualizing catheter tips. 87% of the catheter-enhanced radiographs obtained a rating of 4 or higher, while only 42% of unprocessed radiographs received 4 or more points. Regarding diagnostic confidence for chest pathologies one radiologist rated two catheter-enhanced radiographs higher than the unprocessed radiographs, while all other 186 evaluations rated the catheter-enhanced radiographs equal to (n = 78) or lower than (n = 108) the unprocessed radiographs. Only 60% of the catheter-enhanced radiographs yielded a diagnostic confidence of 4 or higher, while 90% of the unprocessed images received 4 or more points.

CONCLUSION

Catheter-enhanced digital chest radiographs demonstrate improved visualization of low contrast PICC tips in neonates compared to unprocessed radiographs. Furthermore, they enable detection of accompanying chest pathologies. However, definitive diagnosis of chest pathologies should be made on unprocessed radiographs.

Heparin-bonded catheters for prolonging the patency of central venous catheters in children

BACKGROUND

Central venous catheters (CVCs) are a mainstay in the management of critically ill children. However, these catheters are associated with mechanical and infectious complications which reduce their life span. Heparin bonding of catheters has shown promise in animal studies and in adults. This is the first update of a review published in 2007.

OBJECTIVES

The primary objective was to determine the effect of heparin-bonded CVCs on the duration of catheter patency in children. Secondary objectives were to determine the effects of heparin-bonded catheters on catheter-related thrombosis, occlusion, blood stream infection and side effects.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched August 2013) and CENTRAL (2013, Issue 7). The authors searched MEDLINE (1946 to week 3 August 2013).

SELECTION CRITERIA

We included randomized and quasi-randomized controlled trials of heparin-bonded catheters versus non-heparin bonded catheters or antibiotic-impregnated catheters that reported on any of the prespecified outcomes, without language restriction.

DATA COLLECTION AND ANALYSIS

We assessed the methodological quality of the trials using the information provided in the studies and by contacting authors. We extracted data and estimated the effect size reported as risk ratio (RR), risk difference (RD) or number needed to treat (NNT), as appropriate.

MAIN RESULTS

We included two eligible studies with a total of 287 participants; both had good methodological quality. There was no difference in the duration of catheter patency between heparin-bonded and non-heparin bonded catheters (median duration seven days versus six days) reported in one study. There was no difference in the risk of catheter-related thrombosis (two studies, RR 0.34, 95% CI 0.01 to 7.68; I(2) = 80%; RD -0.06, 95% CI -0.17 to 0.06). Data from one study revealed a statistically significant reduction in the risk of catheter occlusion (RR 0.06, 95% CI 0.00 to 1.07; RD -0.08, 95% CI -0.13 to -0.02; NNT 13, 95% CI 8 to 50), catheter-related blood stream infections (RR 0.06, 95% CI 0.01 to 0.41; RD -0.17, 95% CI -0.25 to -0.10; NNT 6, 95% CI 4 to 10) and catheter colonization (RR 0.21, 95% CI 0.06 to 0.71; RD -0.11, 95% CI -0.19 to -0.04; NNT 9, 95% CI 5 to 25) in the heparin-bonded catheter group. The second study did not report on these outcomes. There was no significant difference in risk of thrombocytopenia after catheter placement (RR 0.73, 95% CI 0.38 to 1.39; RD -0.02, 95% CI -0.10 to 0.07).

AUTHORS' CONCLUSIONS

Two eligible studies on the use of heparin-bonded catheters versus placebo in children were identified. Meta-analysis of the two studies revealed no reduction in catheter-related thrombosis with heparin-bonded catheters. One study reported a reduction in catheter-related blood stream infection and colonization following the use of heparin-bonded catheters. The strength of evidence is low and further well-designed multicenter randomized controlled trials are warranted.

Risk factors for peripherally inserted central venous catheter complications in children

IMPORTANCE

Peripherally inserted central venous catheters (PICCs) are prone to infectious, thrombotic, and mechanical complications. These complications are associated with morbidity, so data are needed to inform quality improvement efforts.

OBJECTIVES

To characterize the epidemiology of and to identify risk factors for complications necessitating removal of PICCs in children.

DESIGN

Cohort study.

SETTING

Johns Hopkins Children's Center, Baltimore, Maryland.

PARTICIPANTS

Hospitalized children who had a PICC inserted outside of the neonatal intensive care unit (ICU) from January 1, 2003, through December 31, 2009.

MAIN OUTCOME MEASURES

Complications necessitating PICC removal as recorded by the PICC Team.

RESULTS

During the study period, 2574 PICCs were placed in 1807 children. Complications necessitating catheter removal occurred in 534 PICCs (20.8%) during 46 021 catheter-days (11.6 complications per 1000 catheter-days). These included accidental dislodgement (4.6%), infection (4.3%), occlusion (3.7%), local infiltration (3.0%), leakage (1.5%), breakage (1.4%), phlebitis (1.2%), and thrombosis (0.5%). From 2003 to 2009, complications decreased by 15% per year (incidence rate ratio [IRR], 0.85; 95% CI, 0.81-0.89). In adjusted analysis, all noncentral PICC tip locations-midline (IRR 4.59, 95% CI, 3.69-5.69), midclavicular (2.15; 1.54-2.98), and other (3.26; 1.72-6.15)-compared with central tip location were associated with an increased risk of complications. Pediatric ICU exposure and age younger than 1 year were independently associated with complications necessitating PICC removal.

CONCLUSIONS AND RELEVANCE

Noncentral PICC tip locations, younger age, and pediatric ICU exposure were independent risk factors for complications necessitating PICC removal. Despite reductions in PICC complications, further efforts are needed to prevent PICC-associated complications in children.

The effect of low-dose heparin on maintaining peripherally inserted percutaneous central venous catheters in neonates

OBJECTIVE

To evaluate the effect of low-dose heparin on duration of peripherally inserted percutaneous central venous catheter (PCVC) patency and catheter occlusion.

STUDY DESIGN

Our research was a prospective, randomized, controlled, double-blind clinical study including 246 eligible neonates with PCVCs. It was conducted at the neonatal intensive care unit (NICU) of Diyarbakir Children's Hospital between 1 February 2007 and 31 October 2008. In the heparin group (n=118), the total parenteral nutrition (TPN) solutions contained heparin, which was infused at a rate of 0.5 IU kg⁻¹ h⁻¹ . The no-heparin group (n=121) received TPN fluids without heparin.

RESULT

In the heparin group, the duration of catheter patency was longer than that of the no-heparin group reaching a statistically significant difference (12.4 ± 4.5 vs 9.7 ± 4.0, P<0.0001). In the heparin group, the proportion of patients completing the TPN therapy successfully was higher than in the no-heparin group (P=0.0001; relative risk (RR): 3.32 (95% confidence interval (CI): 1.92 to 5.73)) also demonstrating a statistically significant difference. The rate of catheter occlusion among infants in the heparin group was smaller (P=0.0001; RR: 3.44 (95% CI: 1.92 to 6.44)). There were no statistically significant differences between the two groups in the incidence of other catheter-related problems. The length of the occluded catheter outside the skin, TPN infusion rate and catheter duration time were found to be the factors associated with catheter occlusion. Heparin prevented catheter occlusion with a mechanism unrelated to these factors.

CONCLUSION

In neonates with PCVCs, low-dose continuous infusion of heparin (0.5 IU kg ⁻¹h⁻¹ within TPN fluids is an effective measure in terms of reducing catheter occlusion, allowing successful completion of the therapy, without increasing adverse effects. Furthermore, this effect of heparin may occur independently via occlusion-related factors that we evaluated in the study.

Permanent catheterization of the carotid artery induces kidney infection and inflammation in the rat

Catheterization of the carotid artery and the jugular vein is one of the most commonly applied techniques used to gain intravascular access in pharmacology studies on rodents. We catheterized 10 rats by conventional clean techniques, 10 rats by aseptic techniques and 10 rats by conventional clean techniques using a heparin-coated catheter rather than an ordinary non-coated polyvinyl chloride catheter. In all groups, approximately 80% of the rats developed kidney infection and 10-30% of the rats were septicaemic. Clinical chemistry did not indicate severe kidney damage, but serum haptoglobin and body temperature rises indicated an inflammatory response in rats independent of the surgical method. Heparin coating did not seem to improve the usability of the catheter. It is concluded that this commonly used method for catheterization has an impact on animals that may very well render them unsuitable for the purpose, e.g. pharmacological research, and therefore an alternative method would be preferable.

Heparin-bonded catheters for prolonging the patency of central venous catheters in children

BACKGROUND

Central venous catheters (CVCs) are a mainstay in the management of critically ill children. However, these catheters are associated with mechanical and infectious complications which reduce their life span. Heparin bonding of catheters has shown promise in animal studies and in adults.

OBJECTIVES

The primary objective was to determine the effect of heparin-bonded CVCs on the duration of catheter patency in children. Secondary objectives were to determine the effect of heparin-bonded catheters on catheter related thrombosis, occlusion, sepsis and side effects.

SEARCH STRATEGY

We searched the Cochrane Peripheral Vascular Diseases (PVD) Group Trials Register (inception to August 2007) which contains trials identified through searches of MEDLINE (1966 to August 2007), EMBASE (1980 to August 2007), CINAHL (1982 to August 2007), and hand searches along with the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library 2007, Issue 3.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials of heparin-bonded catheters versus non-heparin bonded catheters or antibiotic-impregnated catheters that reported on any of the prespecified outcomes, without language restriction.

DATA COLLECTION AND ANALYSIS

Methodological quality of the trials was assessed using the information provided in the studies and by contacting authors. Data were extracted and the effect size was estimated and reported as relative risk (RR), risk difference (RD) or number needed to treat (NNT), as appropriate.

MAIN RESULTS

Two eligible studies reflecting 287 patients were included; both had good methodological quality. There was no difference in the duration of catheter patency between heparin bonded and non-heparin bonded catheters (median duration 7 days vs 6 days) reported in one study. There was no difference in the risk of catheter related thrombosis (RR 0.71, 95% CI 0.44 to 1.15; RD -0.05, 95% CI 0.13 to 0.02; I(2) = 79%). Data from one study revealed a statistically significant reduction in the risk of catheter occlusion (RR 0.06, 95% CI 0.00 to 1.07; RD -0.08, 95% CI -0.13 to -0.02; NNT 13, 95% CI 8 to 50), catheter-related infections (RR 0.06, 95% CI 0.01 to 0.41; RD -0.17, 95% CI -0.25 to -0.10; NNT 6, 95% CI 4 to 10) and catheter colonization (RR 0.21, 95% CI 0.06 to 0.71; RD -0.11, 95% CI -0.19 to -0.04; NNT 9, 95% CI 5 to 25) in the heparin-bonded catheter group.

AUTHORS' CONCLUSIONS

Two eligible studies on the use of heparin-bonded catheters versus placebo in children were identified. The use of heparin-bonded catheters is a promising therapy but warrants further studies.

Catheter-Related Central Venous Thrombosis: The Development of a Nationwide Consensus Paper in Italy

Catheter-related central venous thrombosis is a serious complication in patients who need long-term venous access. Though scientific data and clinical experience are steadily increasing, many uncertainties still exist about several aspects of this complication, including etiology, pathogenesis, diagnosis, management, and prevention of this complication. The GAVeCeLT (the Italian Study Group for Long Term Central Venous Access) promoted a nationwide consensus, and 12 experts reviewed systematically all the available literature. A preliminary document was presented and discussed during a specific Consensus Meeting, in front of a panel of more than 80 experts (representing different health professions and disciplines). This led to a prefinal document, which was presented to more than 800 health professionals. After peer review by an external board of experts, the final document was prepared. In this article, methodology and results of the consensus are presented.

In vivo quantitative assessment of catheter patency in rats

Formation of fibrin sleeves around catheter tips is a central factor in catheter failure during chronic implantation, and such tissue growth can occur despite administration of anticoagulants. We developed a novel method for monitoring catheter patency. This method recognizes the progressive nature of catheter occlusion, and tracks this process over time through measurement of changes in catheter resistance to a standardized 1 mL bolus infusion from a pressurized reservoir. Two indirect measures of catheter patency were used: (a) reservoir residual pressure and (b) reservoir discharge time. This method was applied to the study of catheter patency in rats comparing the effect of catheter material (silastic, polyurethane, Microrenathanetrade mark), lock solution (heparin, heparin/dexamethasone) and two different cannulation sites (superior vena cava via the external jugular vein, inferior vena cava via the femoral vein). Our findings reveal that application of flexible smaller-size silastic catheters and a dexamethasone lock solution resulted in prolonged catheter patency. Patency could be maintained over nine weeks with the femoral vein catheters, compared with five weeks with the external jugular vein catheters. The current method for measuring catheter patency provides a useful index for the assessment of tissue growth around the catheter tip. The method also provides an objective and quantitative way of comparing changes in catheter patency for different surgical methods and catheter types. Our method improves on the conventional method of assessing catheter occlusion by judging the ability to aspirate from the catheter.

Pediatric peripherally inserted central catheters: complication rates related to catheter tip location

OBJECTIVE

To compare complication rates between central venous catheter tip location and noncentral tip location after peripherally inserted central catheter (PICC) placement in children.

METHODS

Between 1994 and 1998, data from all children who underwent PICC placement were analyzed. Patient demographics, catheter characteristics, catheter duration, infusate composition, and catheter complications were entered prospectively into a computerized database. Catheter tip locations were determined by fluoroscopy and were defined as central if they resided in the superior vena cava, right atrium, or high inferior vena cava at or above the level of the diaphragm, and as noncentral if located elsewhere. Differences in complication rates between the central and noncentral groups were analyzed.

RESULTS

Data from a total of 1266 PICCs were analyzed from 1053 patients with a mean age of 6.49 +/-.2 years (range: 0-45.0 years). Of the 1266 PICCs, 1096 (87%) were central in tip location, and 170 (13%) were noncentral in tip location. The central group had 42 complications of 1096 catheters (3.8%), while the noncentral group had 49 complications of 170 catheters (28.8%). Controlling for patient age, catheter size, gender, and catheter duration with a logistic regression model, there remained a statistically significant increased likelihood of complication in the noncentral group versus the central group (adjusted odds ratio: 8.28; 95% confidence interval: 5.11-13.43).

CONCLUSIONS

Centrally placed catheter tips are associated with fewer complications than are noncentrally placed catheter tips. Clinicians should ensure that catheter tips reside centrally after PICC placement in infants and children.

Femoral deep vein thrombosis associated with central venous catheterization: results from a prospective, randomized trial

OBJECTIVE

To determine the frequency of central venous catheter-induced deep vein thrombosis of the femoral vein.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Tertiary care center.

PATIENTS

Forty-five patients in a medical-surgical intensive care unit who required central venous catheterization.

INTERVENTIONS

Patients were randomized to receive central venous catheterization in either upper (subclavian or internal jugular veins) or lower (femoral vein) catheterization sites. Lower extremity duplex ultrasound examinations were performed before central venous catheter placement, after removal of the catheter, and 7 days after catheter removal. Ultrasound examinations were reported as positive, nondiagnostic, or negative for deep vein thrombosis.

MEASUREMENTS AND MAIN RESULTS

Of the 21 patients randomized to upper access sites, none developed positive or nondiagnostic duplex ultrasound examinations. Six (25%) of 24 patients randomized to the femoral access site developed lower extremity deep vein thrombosis (p = .02). In addition, seven (29%) patients randomized to the lower access site sustained non-diagnostic ultrasound examinations. A total of 13 (54%) of 24 patients from the lower access group developed abnormal ultrasound examinations (p < .001). Age, duration of catheterization, coagulation profile, deep vein thrombosis prophylaxis, and Acute Physiology and Chronic Health Evaluation II scores were similar between the upper and lower access groups.

CONCLUSIONS

Based on the data from this study, we concluded that femoral vein catheterization is associated with a 25% frequency of lower extremity deep vein thrombosis compared with similar patients receiving subclavian or internal jugular vein catheters. The femoral vein remains an important emergency venous access route. Physicians inserting femoral vein catheters should be aware of the risk of lower extremity deep vein thrombosis and should consider performing lower extremity duplex ultrasound examinations on removal of femoral vein catheters.

Catheter-related thrombosis in critically ill children: comparison of catheters with and without heparin bonding

OBJECTIVE

To compare the incidence of and factors associated with vascular thrombosis after placement of heparin-bonded and standard femoral venous catheters.

DESIGN

Prospective, masked, clinical study.

SETTING

Multidisciplinary, tertiary, pediatric intensive care unit.

PATIENTS

Consecutive cases (n = 50) of critically ill children admitted to a pediatric intensive care unit in whom either a heparin-bonded (n = 25) or a standard (n = 25) femoral venous catheter was placed.

MEASUREMENTS AND MAIN RESULTS

Patients were examined by ultrasonography within 3 days of catheter insertion, weekly while the catheter was in place, and after catheter removal for evidence of vascular thrombosis. Data were collected prospectively regarding clinical evidence of catheter thrombosis, infusate composition, and positive blood culture results. Of 50 patients, 13 (26%) had thrombotic complications, 11 (44%) of the 25 patients in the standard-catheter group, in comparison with 2 (8%) of the 25 patients in the heparin-bonded catheter group (p = 0.004). In addition, there was a significantly higher incidence of positive blood culture results among patients in the standard-catheter group (24% vs 0%; p = 0.009). Positive catheter blood culture results were obtained in 38% of patients with thrombosis versus 3% without thrombosis (p = 0.001). Clinical evidence of thrombosis was found in 69% of patients with, versus 27% of patients without, ultrasound-proved thrombosis (p = 0.007).

CONCLUSION

Heparin bonding of catheters is associated with significantly fewer thrombotic complications. A reduced incidence of positive catheter-related blood culture results may be associated with the absence of thrombosis.

Prolonged barbiturate therapy in a patient with closed head injury and jugular venous thrombosis

The case of a patient who sustained a severe closed head injury complicated by jugular venous thrombosis is presented. Early problems with intracranial pressure were related to bifrontal intracerebral contusions. Jugular vein thrombosis became manifest clinically late in the patient's course and was verified by Doppler ultrasonography. Late problems with intracranial hypertension were presumed to be due to decreased cerebral outflow secondary to the thrombosis. The patient required 4 weeks of a high-dose regimen of pentobarbital to control his intracranial pressure. This is an exceptionally long period of time for a patient to be in barbiturate coma for a closed head injury and still make a satisfactory recovery. The incidence, etiology, prevention, and treatment of upper extremity and jugular venous thrombosis are discussed. The ramifications of jugular venous thrombosis in neurosurgical patients are discussed.

The CCSG prospective study of venous access devices: an analysis of insertions and causes for removal

This is an interval analysis of the 2-year prospective multicenter Childrens Cancer Study Group study of 1,141 chronic venous access devices in 1,019 children with cancer. Device type was external catheter (EC) 72%, totally implantable (TID) 28%, and did not differ for diagnosis or age except more double-lumen devices in bone marrow transplant protocols (77%) and more TIDs in children less than 1 year old (17.7%). Insertion characteristics evaluated in 1,078 (95%) were: operating room placement 99%; general anesthesia 98%; cutdown 67%; percutaneous 33%; atrial position 50%, caval position 50%; and perioperative antibiotics 48%. Vein entry was the external jugular 33%, internal jugular 22%, subclavian 35%, cephalic 7%, and saphenous 3%. Insertion was difficult or very difficult in only 10% and operative complications occurred in only 0.7%. Degree of difficulty bore no relationship to device type or patient age. The reasons for removal in 736 devices (67%) were due to complications in 39%, of which infections were the most frequent. There was some variance between centers ranging from 8.5% to 31% for infection; 2.8% to 24% for dislodgment; and 0% to 13% for occlusion. ECs had a higher risk of dislodgment; elective removals were more frequent in TIDs; there was no difference in infection as a cause for removal between ECs and TIDs. Dislodgment was associated with the shortest distance of the cuff to the skin exit (mean, 4 cm): less than or equal to 2 cm, 49%; greater than 2 cm, 28% (P = .009) and occurred most frequently in the younger patient (18.9%, 0 to 1 years; 0.5%, greater than 8 years.

Deep venous thrombosis of the upper extremity: diagnosis and treatment

Deep vein thrombosis of the upper extremity was long thought to be a benign disease, rarely complicated by pulmonary embolism and associated with minimal long-term morbidity. More recent observations have demonstrated however, that a significant number of patients will continue to have disabling symptoms after treatment with conservative measures and standard anticoagulation therapy, and that pulmonary embolism can occur in the course of the disease. Because of its significant morbidity and increasing incidence, an aggressive emergency department approach to diagnosis and early consideration of fibrinolytic therapy are recommended.

Mortality in patients on home parenteral nutrition

Fifty out of 228 patients recorded on the U.K. Home Parenteral Nutrition Register have died. The earliest to die was at 10 days following the commencement of home parenteral nutrition (HPN), and the longest to die was after 5 1/2 years. Half of the patients who died, did so within 6 months of commencing HPN. Sixty % died of their underlying disease. Most patients with scleroderma or an underlying malignancy are dead within a year of commencing HPN. In contrast, patients with Crohn's disease or the short bowel syndrome due to volvulus do well. In only 14 patients was death attributable to the administration of HPN. In this group the main causes were septicemia, SVC thrombosis, and hepatic failure. Our study suggests that HPN should be used in patients with malignancy and scleroderma only in exceptional circumstances and that further work is necessary for the prevention of SVC thrombosis.

Mechanism of thrombogenesis during total parenteral nutrition: role of catheter composition

Catheter material is considered as one of the main factors of deep venous thrombosis during parenteral nutrition. The effects of five types of catheters (polyethylene, polyurethane, silicone, TFE Teflon, and FEP Teflon) on the vein wall and on the blood flow were compared. Experiments were performed on rabbits in which catheters were inserted into the vena cava. Five series of experiments were performed, each including five animals with the same type of catheter. After 10 days, venograms of the vena cava were performed, animals were then killed and the vena cava was removed with the catheter in situ. The vein and the catheter were macroscopically examined; in cases with thrombosis the clot was weighed. The vein wall and the catheter were examined by conventional microscopy and by electron microscopy, respectively. Obstruction of the venous lumen were significantly more frequent with the rigid catheters than with the soft catheters (p less than 0.001). The most extensive thromboses occurred with the Teflon catheters. The incidence of fibrin sleeves was significantly higher with the soft catheters than with the rigid ones (p less than 0.01). The venographic and macroscopic findings were in agreement in 60-100% of the cases according to the degree of venous obstruction. Catheter surfaces remained unchanged in all cases. The polyethylene catheters induced the most severe intimal inflammatory reactions. Thrombus formation was caused by two mechanisms depending on catheter composition: (1) turbulence caused by the catheter in the blood stream, and (2) platelet aggregation and subsequently, fibrin deposition on the surface of the catheter.