Recombinant tissue plasminogen activator (alteplase) for restoration of flow in occluded central venous access devices: a double-blind placebo-controlled trial--the Cardiovascular Thrombolytic to Open Occluded Lines (COOL) efficacy trial

Therapeutic management of ischemic stroke

Stroke is the third leading cause of years lost due to disability and the second-largest cause of mortality worldwide. Most occurrences of stroke are brought on by the sudden occlusion of an artery (ischemic stroke), but sometimes they are brought on by bleeding into brain tissue after a blood vessel has ruptured (hemorrhagic stroke). Alteplase is the only therapy the American Food and Drug Administration has approved for ischemic stroke under the thrombolysis category. Current views as well as relevant clinical research on the diagnosis, assessment, and management of stroke are reviewed to suggest appropriate treatment strategies. We searched PubMed and Google Scholar for the available therapeutic regimes in the past, present, and future. With the advent of endovascular therapy in 2015 and intravenous thrombolysis in 1995, the therapeutic options for ischemic stroke have expanded significantly. A novel approach such as vagus nerve stimulation could be life-changing for many stroke patients. Therapeutic hypothermia, the process of cooling the body or brain to preserve organ integrity, is one of the most potent neuroprotectants in both clinical and preclinical contexts. The rapid intervention has been linked to more favorable clinical results. This study focuses on the pathogenesis of stroke, as well as its recent advancements, future prospects, and potential therapeutic targets in stroke therapy.

Cancer-Associated Venous Thromboembolism-Diagnostic and Therapeutic Considerations: An Update Based on the Revised AWMF S2k Guideline

Patients with cancer are prone to develop venous thromboembolism (VTE) with negative impact on quality of life, morbidity, and mortality. Treatment of established VTE is often complex in patients with cancer. Treatment of cancer-associated VTE (CAT) basically comprises initial and maintenance treatment, for 3 to 6 months, secondary preventions, and treatment in special situations. Therapeutic anticoagulation is the treatment of choice in CAT. In addition to the efficacy and safety of low-molecular-weight heparin (LMWH) that had been recommended for decades, direct oral anti-factor Xa inhibitors, a subgroup of direct oral anticoagulants (DOACs), demonstrated their advantages along with the accompanying concerns in several randomized controlled treatment trials of CAT. The latest guidelines, such as the German AWMF-S2k Guideline "Diagnostics and Therapy of Venous Thrombosis and Pulmonary Embolism," agree with each other on most aspects with respect to the treatment of CAT. Encompassing recent clinical studies, and meta-analyses, as well as the focus on some special management aspects of CAT, the objective of this review is to present a current overview and recommendations for the treatment of CAT.

Short bowel syndrome: Complications and management

Short bowel syndrome (SBS) occurs when a patient loses bowel length or function significantly enough to cause malabsorption, oftentimes requiring lifelong parenteral support. In adults, this occurs most commonly in the setting of massive intestinal resection, whereas congenital anomalies and necrotizing enterocolitis predominate in children. Many patients with SBS develop long-term clinical complications over time related to their altered intestinal anatomy and physiology or to various treatment interventions such as parenteral nutrition and the central venous catheter through which it is administered. Identifying, preventing, and treating these complications can be challenging. This review will focus on the diagnosis, treatment, and prevention of several complications that can occur in this patient population, including diarrhea, fluid and electrolyte imbalance, vitamin and trace element derangements, metabolic bone disease, biliary disorders, small intestinal bacterial overgrowth, d-lactic acidosis, and complications of central venous catheters.

Effectiveness of mechanical recanalization for intraluminal occlusion of totally implantable venous access ports

PURPOSE

To evaluate if the mechanical injection of saline is effective in restoring patency of a totally implantable venous access port (TIVAP) with an intraluminal occlusion.

MATERIALS AND METHODS

From January 2017 to June 2019, 64 cases of dysfunction of a TIVAP were referred to interventional radiology. Among these, 16 cases showed normal function of the TIVAP, 19 cases the showed the appearance of a fibroblastic sheath, and 29 cases showed intraluminal occlusion. Mechanical recanalization was performed for intraluminal occlusion of the TIVAP with an indeflator and a 20G non-coring needle. Linograms were performed in all recanalized cases. The success or failure of recanalization and the pressure of the indeflator were recorded. Linograms were evaluated for breakage or migration of catheters. Medical records were retrospectively reviewed.

RESULTS

Among the 29 intraluminal occlusion cases, 24 cases (82.7%) were recanalized by mechanical recanalization via an indeflator. The pressure of the indeflator ranged from 29 to 220 psi (median: 118 psi). Linograms revealed breakage of the catheter of the TIVAP in two failed cases. The median interval from implantation to dysfunction was 405 days (range: 43-1723 days). The median interval from last use to dysfunction was 8 days (mean: 15.4 days; range: 1-119 days). The median re-occlusion free period after successful mechanical recanalization was 100.5 days (range: 6-859 days).

CONCLUSION

In the absence of an available thrombolytic agent, mechanical injection of saline was a tolerable alternative method for restoring occluded catheters and sustaining the function of catheters. Because breakage of the catheter can occur during mechanical recanalization of a TIVAP, a linogram should follow the procedure.

Assessing and Restoring Patency in Midline Catheters

Maintaining and restoring patency in midline catheters has been a significant issue in the hospitalized patient requiring a multitude of infusates and frequent blood specimen collection. Currently, clinicians may not use this device as often as clinically indicated because they lack an approved intervention to treat thrombotic occlusions. The purpose of this research was to show evidence that alteplase, a US Food and Drug Administration-approved thrombolytic for central vascular access devices, is a safe and effective thrombolytic for midline catheters. A prospective open label study of 497 midline catheters was conducted from July 2018 to December 2018. Of those studied, 112 devices were treated with 1 mg of alteplase, and 109 had patency restored with 1 dose. None of the 112 patients had a major adverse event, and only 1 minor event was recorded and was resolved without removal of the midline catheter. Treating occluded central vascular access devices with 2 mg of alteplase has been safe and effective since 2001. With this research, safety and efficacy appears to be established for 1 mg of alteplase, repeat times 1 mg if necessary, in midline catheters. With the option to treat patients with occluded midline catheters rather than replace, clinicians can reduce cost, increase patient satisfaction, and preserve vein health.

Long-term vascular access in differently resourced settings: a review of indications, devices, techniques, and complications

Central venous access is frequently essential for the management of many acute and chronic conditions in children. Millions of central venous access devices (CVADs) are placed each year. In this review article, we discuss the indications for long-term vascular access, the types of devices available, the state of the art of central venous cannulation and device placement, and the complications of long-term central venous access. We pay a special attention to the challenges of, and options for long-term central venous access, also those in developing countries, with limited financial, human, and material resources.

Interventions for Occluded Central Venous Catheters: A Meta-analysis

CONTEXT

Thrombotic occlusion is 1 of the most frequent complications in catheters implanted in children.

OBJECTIVE

To identify the interventions used to treat thrombotic events in long-term central venous catheters in pediatric patients with cancer.

DATA SOURCES

Electronic searches were performed in the Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Register of Controlled Trials, Latin American and Caribbean Health Sciences Literature, LIVIVO, PubMed, Scopus, Web of Science, Google Scholar, OpenGrey, and ProQuest databases. There were no restrictions on language or publication period.

STUDY SELECTION

This systematic review was performed in 2 phases and included clinical trials and observational studies on drugs used to treat thrombotic catheter events in pediatric patients with cancer. The review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis checklist, and the protocol was registered at PROSPERO (identifier CRD42018083555).

DATA EXTRACTION

The authors evaluated the quality of included studies using the Methodological Index for Nonrandomized Studies and Grading of Recommendations Assessment, Development and Evaluation methods. The meta-analysis was performed by using Stata software.

RESULTS

Ten studies were included. The drugs used to restore catheter function were alteplase, urokinase, and streptokinase. A meta-analysis of 6 studies revealed an overall restoration rate of 88% for alteplase.

LIMITATIONS

Reference studies were excluded when it was not possible to reliably extract data that met the inclusion criteria of this review. Sampling issues (absence of randomization, blinding, or a control group) were the main methodologic concerns for the included articles.

CONCLUSIONS

On the basis of the evidence obtained, thrombolysis is effective and potentially safe in this population.

Angioedema Risk Associated With Central Vascular Access Device Declotting

Little is known about the risk of angioedema with low-dose alteplase administration in the treatment of thrombotically occluded central vascular access devices (CVADs). To identify potential cases, the US Food and Drug Administration Adverse Event Reporting System database was searched. Between March 15, 2001, and August 15, 2018, there were 568 low-dose alteplase reports. Of these, 11 appear to be related to complications associated with a device or device occlusion that resulted in an angioedema-like reaction. This suggests that angioedema is a potential complication of alteplase when used for declotting CVADs-a complication that nurses should know how to recognize and treat.

Interventions to obstructive long-term central venous catheter in cancer patients: a meta-analysis

PURPOSE

The aim of this systematic review was to identify the interventions used to treat obstructive events, whether thrombotic or non-thrombotic, in long-term central venous catheters (LT-CVC) in cancer patients.

METHODS

This review included clinical trials and observational studies reporting the drugs used to treat obstructive catheter events in cancer patients. The authors developed specific search strategies for CINAHL, Cochrane CENTRAL, LILACS, PubMed, Scopus, Web of Science, Google Scholar, Open Grey, and ProQuest. The authors evaluated methodological quality of included studies using criteria from Cochrane's Collaboration Tool and the Methodological Index for non-randomized studies (MINORS). The quality of evidence was analyzed by using GRADE's software.

RESULTS

More than 9000 articles were found across the databases. After duplicates removed, the studies were selected in 2 phases. After that, only 15 studies were included. The drugs used to restoration of catheter function were urokinase (53.3%), alteplase (20%), tenecteplase (13.3%), reteplase (6.7%), recombinant urokinase (6.7%), and staphylokinase (6.7%). The results of meta-analysis of 14 studies showed an overall restoration rate of ~ 84%. The drug type meta-analysis demonstrates a success rate of ~ 84%, ~ 92%, and ~ 84% for urokinase, alteplase, and tenecteplase groups, respectively. The main methodological problem in included articles concerns the sample. The quality of evidence ranged from very low to high.

CONCLUSION

The most common interventions used to treat thrombotic catheter occlusion in cancer patients were urokinase and alteplase. No evidence was found about the treatment for non-thrombotic occlusion, thus elucidating an important gap to be investigated.

Spanish Clinical Guidelines on Vascular Access for Haemodialysis

Vascular access for haemodialysis is key in renal patients both due to its associated morbidity and mortality and due to its impact on quality of life. The process, from the creation and maintenance of vascular access to the treatment of its complications, represents a challenge when it comes to decision-making, due to the complexity of the existing disease and the diversity of the specialities involved. With a view to finding a common approach, the Spanish Multidisciplinary Group on Vascular Access (GEMAV), which includes experts from the five scientific societies involved (nephrology [S.E.N.], vascular surgery [SEACV], vascular and interventional radiology [SERAM-SERVEI], infectious diseases [SEIMC] and nephrology nursing [SEDEN]), along with the methodological support of the Cochrane Center, has updated the Guidelines on Vascular Access for Haemodialysis, published in 2005. These guidelines maintain a similar structure, in that they review the evidence without compromising the educational aspects. However, on one hand, they provide an update to methodology development following the guidelines of the GRADE system in order to translate this systematic review of evidence into recommendations that facilitate decision-making in routine clinical practice, and, on the other hand, the guidelines establish quality indicators which make it possible to monitor the quality of healthcare.

Hemodialysis Catheter-Related Central Venous Thrombosis: Clinical Approach to Evaluation and Management

Central venous catheter (CVC) use is common among patients undergoing hemodialysis. Catheter-related vascular thrombosis is a frequent complication, which results in catheter dysfunction. This may eliminate the affected vein as a potential route of vascular access and leads to significant morbidity of the limbs involved. Despite increasing prevalence, there is a dearth of evidence-based guidelines for managing such catheter-related thrombi, often leading to treatment dilemmas in clinical practice. Minimizing the use of CVCs for hemodialysis remains the best approach in preventing such adverse complications. Furthermore, meticulous planning and care when using such catheters in unavoidable circumstances along with vigilant surveillance to identify complications early will allow to avoid associated morbidity.

ACR Appropriateness Criteria® Radiologic Management of Central Venous Access

Obtaining central venous access is one of the most commonly performed procedures in hospital settings. Multiple devices such as peripherally inserted central venous catheters, tunneled central venous catheters (eg, Hohn catheter, Hickman catheter, C. R. Bard, Inc, Salt Lake City UT), and implantable ports are available for this purpose. The device selected for central venous access depends on the clinical indication, duration of the treatment, and associated comorbidities. It is important for health care providers to familiarize themselves with the types of central venous catheters available, including information about their indications, contraindications, and potential complications, especially the management of catheters in the setting of catheter-related bloodstream infections. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Efficacy of Low-Dose Alteplase for Treatment of Hemodialysis Catheter Occlusions

Background

Traditionally, alteplase 2 mg/lumen doses have been used to treat central venous catheter (CVC) occlusions. On January 20, 2004, our hemodialysis (HD) unit implemented a new protocol to utilize alteplase 1 mg/lumen doses for catheter occlusion.

Objectives

The objectives were to 1) assess the efficacy of low-dose alteplase in restoring HD catheter patency; 2) determine the duration of CVC patency as determined by need for further alteplase doses, or radiological or surgical line interventions; and 3) evaluate the financial implications of the new protocol.

Methods

The study was a prospective, open-label trial of 50 consecutive HD patients with permanent, tunnelled CVC lines. A treatment course consisted of 1 or 2 doses of alteplase instilled for 60 minutes then aspirated or as an overnight (48–72 hour) dwell until the next HD. The patient's first alteplase dose following implementation of the new protocol was evaluated. Patients were followed for two months to record need for further alteplase treatment courses, and four months to document radiological or surgical line interventions. The primary outcome was to assess successful restoration of catheter patency defined as the ability of alteplase to restore or maintain HD blood flow rate at or above 300 mL/minute. A financial analysis compared alteplase costs for 11 months prior to and after implementation of the new protocol.

Results

Alteplase 1 mg/lumen doses restored catheter patency in 72% of HD patients with one dose, increasing to 83% with a second dose. Sixty-two percent of patients required a subsequent alteplase course with a median time to next treatment of 14 days and a median of 2 courses/patient. Radiological interventions were ordered in 38% of patients resulting in 8 lines replacements and 7 line strippings. Financial savings with the new low-dose protocol were ~CDN$22,000.

Conclusion

Low dose alteplase 1 mg/lumen successfully treated occlusion of permanent hemodialysis catheters, with a resulting cost reduction.

Twenty-five Years of Advances in Vascular Access: Bridging Research to Clinical Practice

Vascular access has become a key component for a multitude of IV therapies, including parenteral nutrition. Access of the central venous system has been long recognized for its associated complications of infection, thrombosis, and occlusion. Over the past 25 years, clinical practice based on research and innovation has attempted to decrease complication rates and therefore improve the safety of vascular access. This article highlights the research and its influence on catheter care procedures, technology, and education that has led to advances in vascular access. An improved understanding of the pathophysiology associated with catheter-related complications and an ongoing evaluation of new treatment modalities has provided clinicians today with new options for improved patient care and the ability to preserve vascular access options for patients.

Enzymatic Stability of Alteplase Solution for Injection: Effect of Various Methods of Thawing Frozen Solutions

Objective

To modify and evaluate an established chromogenic assay protocol for measuring plasminogen activator inhibitor type-1 (PAI-1) activity to measure tissue plasminogen activator (tPA) activity and compare the enzymatic activity of alteplase as a function of the conditions under which it is thawed.

Methods

A 50 mg vial of alteplase was reconstituted with sterile water to make a 1 mg/mL stock solution (nominal concentration). Plastic syringes were loaded with 0.5 mL of alteplase stock solution and stored at -20°C. After 8 days, samples were thawed by 3 methods - via body temperature (37°C), room temperature (20°C), or in a refrigerator (2°C). Thaw times were recorded. The thawed solutions, along with a freshly prepared alteplase solution, were assayed using the modified protocol of the Spectrolyse PAI-1 kit to determine residual tPA enzyme activity.

Results

Validation of the modified protocol for the Spectrolyse PAI-1 kit used to measure tPA activity produced a linear response with coefficients of determination (R2) of greater than 0.9977 when assayed on 2 separate days, which corresponded to an enzymatic activity accuracy between 98.3% and 108.3%. The average percent residual tPA enzyme activity of samples from each group compared to the freshly prepared solution was 106%, 98.7%, and 91.5% for samples thawed at body temperature, room temperature, and refrigerated, respectively.

Conclusion

Modifications to the standard procedure for the Spectrolyse PAI-1 kit allows for accurate determination of tPA activity in aqueous based reconstituted solutions of alteplase. Under thawed conditions, alteplase retained greater than 91% enzyme activity as compared to a freshly prepared control.

Use of Alteplase for Clearing Peritoneal Dialysis Catheter Occlusion

Background

Peritoneal dialysis (PD) catheter complications account for 20% of all transfers from PD to hemodialysis. One complication is outflow obstruction caused by fibrin deposits within the lumen of the catheter. Alteplase is frequently used to clear fibrin deposits in PD catheters that are refractory to other therapies. However, the literature basis for this practice is unclear.

Method

A review of the literature was conducted to determine the evidence existing for alteplase use in PD catheter occlusion due to fibrin. A literature search of MEDLINE (1967-present) was conducted using the search terms "alteplase", "peritoneal dialysis catheter", "occlusion", "fibrin", and "tissue plasminogen activator". Referenced citations were also searched for pertinent material. All data concerning the use of alteplase for peritoneal dialysis catheter occlusion were included in this review. The search resulted in 1 open-label pilot study, 3 case series, and 2 case reports of alteplase use in declotting occluded PD catheters.

Results

Based on the data, alteplase therapy cleared the occlusion of PD catheters in the majority of cases. In those that were unsuccessful, other surgically correctable and mechanical causes were identified in most cases.

Conclusion

Alteplase appears to be an intriguing alternative to the surgical removal of the PD catheter in patients with catheter occlusion due to fibrin. Although not inexpensive, it appears safe and may decrease the need for surgical correction of occluded catheters.

The Influence of a Novel Needleless Valve on Central Venous Catheter Occlusions in Pediatric Patients

Background: Although it is common for central line catheters to develop a thrombotic occlusion, pediatric patients are at especially high risk of occlusion due to smaller vessels, smaller-gauge catheters, and slower rates of infusion. Mitigating catheter occlusions is costly, requiring tissue plasminogen activator, supplies, and nursing time. Our facility tested a novel neutral displacement needle-free valve designed to reduce occlusion.

Methodology: The organization determined a baseline occlusion rate for Hickman/Broviac catheters, in our 38-bed inpatient hematology/oncology department and our outpatient hematology/oncology clinic from August 2010 through October 2010. In 2011, a premarket test of the Neutron device (ICU Medical, San Clemente, CA) was conducted on the units. Based on the positive trial results, it was decided to implement the device housewide in December 2012.

Results: A comparison of baseline central line complete occlusion rates from August to October 2010 with Neutron trial data from July to October 2011. This pilot project demonstrated a 74.3% reduction (from a rate of 3.82 to a rate of 0.98) in all hematology/oncology department Hickman and Broviac complete catheter occlusions. Subsequently, comparing 5 months of housewide occlusion data from June through October 2012 to 2013, complete occlusions fell by 32.1% (from a rate of 1.56 to a rate of 1.06).

Conclusions: The use of the Neutron needle-free catheter patency device was associated with a reduction in complete occlusions. The corresponding reduction in treatment delays, nursing time spent managing occluded catheters, and fewer needlesticks to patients likely translates to financial benefit for the organization and improved patient and family satisfaction.

Efficacy and safety of using L-cysteine as a catheter-clearing agent for nonthrombotic occlusions of central venous catheters in children

Critically ill pediatric patients, especially in the intensive care unit, receive multiple medications and have a higher risk of central venous catheter (CVC) occlusion. If an occlusion occurs immediately after the administration of multiple medications or incompatible medications, either an acidic solution such as 0.1 N hydrochloric acid (HCl) or a basic solution of 1 mEq/mL sodium bicarbonate or 0.1 N sodium hydroxide can be used. However, compounding and storing of 0.1 N HCl has become more complex due to USP <797> guidelines for sterile compounding, and an alternative is needed. We report a series of cases in which L-cysteine was used instead of HCl to clear CVCs occluded due to administration of multiple medications. L-cysteine is a commercially available, sterile solution with a pH of 1–2.5. CVC occlusion was resolved in 10 of the 16 episodes in 13 patients. Two of the 16 occlusions were phenytoin related and would not have responded. An L-cysteine dose of 50 mg was used during 10 of the 16 episodes, 100 mg during 5 episodes, and 25 mg during 1 episode. A correlation between catheter clearance and dose was not observed. Occlusion resolution due to L-cysteine was not correlated to the prior use of tissue plasminogen activator. Metabolic acidosis, adverse effects, or damage to the catheters due to L-cysteine were not observed. On the basis of this limited experience, we propose L-cysteine as an effective alternative to 0.1 N HCl for clearing CVC occlusions caused by drugs with an acidic pKa.

Intraluminal Volume Dose Alteplase for the Clearance of Occluded Peripherally Inserted Central Catheter Lines at a Long-Term Acute Care Hospital: Efficacy and Economic Impact

PURPOSE

To evaluate the efficacy and economic impact of a maximum of 2 doses of intraluminal volume 1 mg/1 mL dose alteplase for the clearance of occluded peripherally inserted central catheter (PICC) lines at a long-term acute care hospital (LTACH).

METHODS

Open-label, nonrandomized quasi-experimental trial taking place over a 3-month period from December 2013 to March 2014. Patients had a standing order of either standard (2 mg/2 mL) or intraluminal volume (1 mg/1 mL) dose alteplase entered for any potential occlusions. The primary efficacy outcome was restored line patency after a maximum of 2 doses of alteplase. Secondary efficacy outcomes included restored patency after 1 dose of alteplase, reocclusion rate, mean time to reocclusion, and mean number of occlusions per patient.

RESULTS

A total of 168 patients were enrolled into the study (intraluminal volume, n = 54; standard, n = 114) and a total of 270 occlusions were recorded; 90 received intraluminal volume dose alteplase and 180 received the standard dose. The primary efficacy endpoint was 93.3% for the intraluminal volume dose group and 94.4% for the standard dose group. Secondary outcomes were similar between groups. The average cost per dose was $123.77 and $60.62 for the standard and intraluminal volume dose alteplase groups, respectively.

CONCLUSION

For the clearance of occluded PICC lines at our LTACH, there was no statistical difference in the efficacy of a maximum of 2 doses of intraluminal volume dose alteplase versus the standard dose. Use of intraluminal volume dose alteplase was found to be significantly more cost-effective.

Thrombolytic Therapy Using Urokinase for Management of Central Venous Catheter Thrombosis

Purpose:

The management of central venous catheters (CVCs) and catheter thrombosis vary among centers, and the efficacy of the methods of management of catheter thrombosis in CVCs is rarely reported. We investigated the efficacy of bedside thrombolysis with urokinase for the management of catheter thrombosis.

Materials and Methods:

We retrospectively reviewed data from patients who had undergone CVC insertion by a single surgeon in a single center between April 2012 and June 2014. We used a protocol for the management of CVCs and when catheter thrombosis was confirmed, 5,000 U urokinase was infused into the catheter.

Results:

A total of 137 CVCs were inserted in 126 patients. The most common catheter-related complication was thrombosis (12, 8.8%) followed by infection (8, 5.8%). Nine of the 12 patients (75%) with catheter thrombosis were recanalized successfully with urokinase. The rate of CVC recanalization was higher in the peripherally inserted central catheter (PICC) group (87.5%) than the chemoport group (50%). Reintervention for catheter-related thrombosis was needed in only 2.2% of patients when thrombolytic therapy using urokinase was applied. Age <60 years (P=0.035), PICC group (P=0.037) and location of the catheter tip above the superior vena cava (P=0.044) were confirmed as independent risk factors for catheter thrombosis.

Conclusion:

Thrombolysis therapy using urokinase could successfully manage CVC thrombosis. Reintervention was rarely needed when a protocol using urokinase was applied for the management of CVC thromboses.

Comparison of hospital length of stay, costs, and readmissions of alteplase versus catheter replacement among patients with occluded central venous catheters

BACKGROUND

Central venous catheter (CVC) occlusion is common, affecting 30% of all CVCs.

OBJECTIVE

To compare length of stay (LOS), costs, and readmissions associated with the use of alteplase to clear catheter blockage to outcomes associated with catheter replacement.

DESIGN

Retrospective observational study utilizing a large hospital database.

PARTICIPANTS

Hospitalized patients treated for catheter occlusion from January 2006 to December 2011.

MAIN MEASURES

Univariate analyses of patient characteristics and treatment patterns and multivariable regression analyses of postocclusion hospital costs, LOS, and 30- and 90-day readmissions were conducted.

KEY RESULTS

We included 34,579 patients treated for a CVC occlusion by replacement (N=1028) or by alteplase (2 mg) administration (N=33,551). Patients receiving alteplase were somewhat younger than those having catheter replacement (60 ± 19 vs 62 ± 20 years old, P=0.0002). After adjusting for patient and hospital factors via regression modeling, average daily postocclusion costs were $317 lower for alteplase recipients than for catheter replacement patients (95% confidence interval [CI]: 238.22-392.24; P<0.0001). Adjusted total postocclusion costs were $1419 lower for alteplase recipients versus patients receiving catheter replacement (95% CI: 307.27-2458.12; P=0.0121). Postocclusion operating room/surgery, radiology, and supply costs were significantly lower for alteplase recipients (P<0.001). Average adjusted postocclusion LOS was similar for both groups (P>0.05). Odds of readmission were not significantly different at 30 or 90 days.

CONCLUSIONS

Among patients treated for an occluded CVC, alteplase-treated patients had lower daily and total postocclusion costs than patients receiving catheter replacement. Cost differences were mainly driven by lower operating room/surgery, radiology, and supplier costs.

Alteplase infusion versus dwell for clearance of partially occluded central venous catheters in critically ill pediatric patients

OBJECTIVE

To evaluate the efficacy and safety of alteplase infusions and alteplase local instillations (dwells) to clear partially occluded central venous catheters in critically ill children.

DESIGN

Retrospective study.

SETTING

PICU in a single, tertiary care, academic children's hospital.

PATIENTS

Retrospective review of the medical records of all critically ill pediatric patients less than 18 years old who received an alteplase infusion or dwell as the treatment for a partial central venous catheter occlusion. The typical infusion regimen was to administer 0.1 mg/kg of body weight (maximum, 2 mg/dose) of alteplase in 25 mL of 0.9% sodium chloride over 3 hours. The standard dwell was to administer and aspirate alteplase in a 1 mg/mL concentration as a fixed dose as ordered by the prescriber (maximum, 2 mg/dose). Efficacy was defined as documentation of positive blood return from the catheter. Radiology reports, nursing and physician documentation, and laboratory values were reviewed to assess for bleeding events.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One hundred fifty occlusion events were included for analysis. Overall, 72 of 84 alteplase infusions (86%) and 53 of 66 alteplase dwells (80%) resulted in resolution of the lumen occlusion event as documented by positive blood return from the catheter after a maximum of two doses (p = 0.39). One major bleeding event occurred in each arm; both were deemed unlikely related to alteplase.

CONCLUSIONS

Alteplase infusions to clear partially occluded central venous catheters appear to be as efficacious as alteplase dwells in critically ill children. In occlusions treated with an infusion, more occlusions resolved in older and larger patients and in patients with catheters in place less than 7 days. In occlusions treated with a dwell, more occlusions resolved in smaller catheters. The safety profile for both infusions and dwells was acceptable for the pediatric critically ill population.

Clinical guidelines on central venous catheterisation. Swedish Society of Anaesthesiology and Intensive Care Medicine

Safe and reliable venous access is mandatory in modern health care, but central venous catheters (CVCs) are associated with significant morbidity and mortality, This paper describes current Swedish guidelines for clinical management of CVCs The guidelines supply updated recommendations that may be useful in other countries as well. Literature retrieval in the Cochrane and Pubmed databases, of papers written in English or Swedish and pertaining to CVC management, was done by members of a task force of the Swedish Society of Anaesthesiology and Intensive Care Medicine. Consensus meetings were held throughout the review process to allow all parts of the guidelines to be embraced by all contributors. All of the content was carefully scored according to criteria by the Oxford Centre for Evidence-Based Medicine. We aimed at producing useful and reliable guidelines on bleeding diathesis, vascular approach, ultrasonic guidance, catheter tip positioning, prevention and management of associated trauma and infection, and specific training and follow-up. A structured patient history focused on bleeding should be taken prior to insertion of a CVCs. The right internal jugular vein should primarily be chosen for insertion of a wide-bore CVC. Catheter tip positioning in the right atrium or lower third of the superior caval vein should be verified for long-term use. Ultrasonic guidance should be used for catheterisation by the internal jugular or femoral veins and may also be used for insertion via the subclavian veins or the veins of the upper limb. The operator inserting a CVC should wear cap, mask, and sterile gown and gloves. For long-term intravenous access, tunnelled CVC or subcutaneous venous ports are preferred. Intravenous position of the catheter tip should be verified by clinical or radiological methods after insertion and before each use. Simulator-assisted training of CVC insertion should precede bedside training in patients. Units inserting and managing CVC should have quality assertion programmes for implementation and follow-up of routines, teaching, training and clinical outcome. Clinical guidelines on a wide range of relevant topics have been introduced, based on extensive literature retrieval, to facilitate effective and safe management of CVCs.

Individual lytic efficacy of recombinant tissue plasminogen activator in an in vitro human clot model: rate of "nonresponse"

OBJECTIVES

Recombinant tissue plasminogen activator (rt-PA) is a lytic medication widely used in the emergency department to treat acute thrombotic disorders such as ischemic stroke and myocardial infarction. It is known in the clinical use of this drug that it can be less effective in approximately 25% of individuals receiving such treatment. However, there are no data on the variation of lytic efficacy of rt-PA in decreasing individuals' clot size over time. In this study, in vitro lytic efficacy was determined by measuring the decrease in clot diameter after 30 minutes of drug exposure. The authors sought to explore whether there are individuals who do not respond to this lytic therapy and to estimate the rate of nonresponse.

METHODS

Human whole blood clots were made from blood drawn from 22 adult volunteers. The only exclusion criterion was the use of aspirin within 72 hours of the blood draw. Blood clots were allowed to spontaneously form at room temperature and were then incubated at 37°C for 3 hours to ensure complete clot retraction. Sample clots from the same individuals were then exposed to human fresh-frozen plasma (hFFP) control or rt-PA in hFFP (rt-PA) at a concentration of 3.15 μg/mL. All clots were exposed at 37°C for 30 minutes, and clot diameter was measured as a function of time, using a microscopic imaging technique. The fractional clot loss (FCL), which is the percentage decrease in clot diameter at 30 minutes, was used as a measure of lytic efficacy.

RESULTS

Means with standard deviation (SD) FCL values were 8.6% (±3.0%) for control and 20.6% (±9.3%) for rt-PA-treated clots. The mean (±SD) difference in FCL values was 12.0% (±8.8%) and was significant (p < 0.05, paired t-test). Five of the 22 subjects (23%) were "rt-PA nonresponders," in that their FCL (rt-PA) values fell within that of the FCL control values.

CONCLUSIONS

Overall, rt-PA does not produce clot lysis in vitro in clots from a substantial minority of the population, likely due to individual variations in clot composition and structure.

Alteplase for the treatment of catheter occlusion in pediatric patients

OBJECTIVE

To review the literature pertaining to the efficacy of alteplase for restoration of patency of occluded venous and dialysis catheters in pediatric patients.

DATA SOURCES

A MEDLINE search was conducted and cross-referenced with an EMBASE search through November 2012. Search terms included alteplase, tissue plasminogen activator, and catheter.

STUDY SELECTION AND DATA EXTRACTION

Search results were limited to humans, English language, and ages from neonates to 18 years. Pertinent studies discussing efficacy of alteplase for restoration of occluded venous or dialysis catheter function were included. Case reports, review articles, and studies that specified inclusion of hemophilia patients or more than 75% of children with malignancy were excluded.

DATA SYNTHESIS

Fibrinolytics are the drug class of choice for restoration of patency (defined as the ability to withdraw a blood sample) of thrombus-occluded catheters. The trials used to support Food and Drug Administration approval of alteplase for central venous catheter (CVC) occlusions generally had low pediatric enrollment; however, additional small studies are available that support use of alteplase for this indication in children. Alteplase doses of 0.5-2 mg instilled into the lumen of a CVC with dwell times ranging from 30 to more than 240 minutes plus the potential for repeat dosing were reported. Overall efficacy ranged from approximately 50% to 90%, with greater efficacy generally reported with larger doses and longer dwell times. Alteplase doses of 2-2.5 mg with dwell times of 60-120 minutes were observed in 2 studies of occluded peritoneal or hemodialysis catheters, in which efficacy was reported in 57-100% of cases. Limitations of current studies of alteplase for catheter occlusion in children include small study populations and relative lack of pediatric-specific prospective trials.

CONCLUSIONS

Alteplase appears to show efficacy for treatment of thrombus-related venous catheter occlusion in pediatric patients; however, data regarding its use in occluded dialysis catheters are limited.

Review article: the management of long-term parenteral nutrition

BACKGROUND

Home parenteral nutrition (HPN) is currently the management of choice for patients with chronic intestinal failure.

AIM

To summarise the major issues in delivering long-term parenteral nutrition (>3 months) and assess outcome as per complications, mortality and quality of life. To assess the evidence for the therapeutic use of trophic factors such as teduglutide and to review evolving therapeutic options in the treatment of chronic intestinal failure.

METHODS

A literature search using PubMed and MEDLINE databases was performed.

RESULTS

Safe delivery of HPN relies upon individualised formulations of parenteral nutrition administered via carefully maintained central venous catheters by trained patients or carers, supported by a skilled multidisciplinary team. Early diagnosis and treatment of complications including catheter-associated blood stream infection (reported incidence 0.14-0.83 episodes/patient-year on HPN) and central venous thrombosis (reported incidence 0.03 episodes/patient-year) is important to minimise mortality and morbidity. There is a significant variation in the reported incidence of both hepatobiliary complications (19-75%) and advanced liver disease (0-50%). Five-year survival rates in large centres are reported between 60% and 78% with survival primarily related to underlying diagnosis. Long-term survival remains higher on HPN than with intestinal transplantation. The role of intestinal lengthening procedures is yet to be validated in adults.

CONCLUSIONS

Home parenteral nutrition delivered by skilled nutrition teams has low incidences of catheter-related complications. Most deaths relate to the underlying disease. Therapies such as teduglutide and small bowel transplantation appear promising, but home parenteral nutrition appears likely to remain the bedrock of management in the near term.

A prospective observational study of the outcome of central venous catheterization in 100 patients

CONTEXT

To Study the outcome following central vein catheterization in patients receiving chemotherapy.

AIMS

To Study the outcome of central venous catheterization in terms of difficulty during insertion, duration, incidence of infections and other complications and reasons for removal.

SETTINGS AND DESIGNS

Prospective observational study conducted in 100 patients attending to Gujarat Cancer and Research Institute.

MATERIALS AND METHODS

Both onco-medical and onco-surgical patients who required insertion of central venous catheters were enrolled after ethical approval from June 2008 to November 2010. The study comprised 100 patients.

STATISTICAL ANALYSIS USED

Mean and percentage.

RESULTS

Mean duration of the indwelling catheter was 109 days for Hickman catheter, 39 days for cavafix and 59 days for certofix. Difficulty in insertion and arrhythmias were common complications. There were no incidences of major life threatening complications. Catheter related infection was 30%. The commonest reason for catheter removal was treatment completion 72%. The next frequent cause was catheter infection 14% and patient death 6%.

CONCLUSIONS

Even though central venous catheterization is associated with acceptable complications, they serve a useful aid in management of patients on chemotherapy.

Interventions for restoring patency of occluded central venous catheter lumens

BACKGROUND

Central venous catheters (CVCs) facilitate the administration of intravenous drugs, fluids, blood products and parenteral nutrition to patients with either chronic disease or critical illness. Despite a pivotal role within medical management, a common complication associated with CVC use is occlusion of the CVC lumen(s). CVC occlusion can interrupt and cause serious delays in administration of treatment interventions.

OBJECTIVES

The primary objective of this review was to assess the efficacy and safety of different interventions used to restore patency of occluded CVC lumens, in adults and children.

SEARCH METHODS

We identified trials by searching the Cochrane Central Register of Clinical Trials (CENTRAL) (The Cochrane Library 2011, Issue 9); OvidSP MEDLINE (1950 to September 2011); OvidSP EMBASE (1980 to September 2011) and NHS Evidence CINAHL (1982 to September 2011). We also searched clinical trial registers, handsearched reference lists, contacted pharmaceutical companies and authors of publications that met the inclusion criteria to identify trials.

SELECTION CRITERIA

We selected randomized controlled trials which investigated the efficacy of an intervention (chemical, surgical or drug) used to restore patency to an occluded CVC lumen, in either adults or children.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed those studies that met the inclusion criteria for quality and extracted the relevant data using a standardized form.

MAIN RESULTS

No studies were found that investigated the efficacy and safety of either chemical or surgical interventions.Seven studies (eight papers) with a total of 632 participants were identified from the search. They investigated different comparisons, strengths of thrombolytic or anticoagulant drug interventions for treating CVC lumen occlusion thought to be caused by a thrombus.There was low quality evidence from a meta-analysis of two studies suggesting that urokinase (various strengths) was more effective than placebo for restoring patency to occluded CVC lumens in adults and children with underlying medical conditions (relative risk (RR) 2.09, 95% confidence interval (CI) 1.47 to 2.95), with a number needed to treat of 4 (95% CI 2 to 8). There was insufficient evidence to draw conclusions on the safety of urokinase.The overall quality of the evidence provided by these studies was low to very low due to one or more domains being assessed as either at 'unclear risk of bias' or 'high risk of bias'. Furthermore, the total number of participants in these studies was small and consequently may lead to spurious results.

AUTHORS' CONCLUSIONS

There is inadequate evidence to draw strong conclusions on the efficacy or safety of the drug interventions included in this review. There is some low quality evidence from a meta-analysis of two studies investigating urokinase (various strengths) and some very low evidence from two single studies investigating alteplase 2 mg/2 mL that suggest that these two drug interventions may be effective in treating withdrawal or total occlusion of CVC lumens caused by thrombosis. Further high quality, sufficiently powered research is still required to look at the efficacy and safety of urokinase, alteplase and other chemical, surgical and drug interventions for treating CVC lumen occlusion. Research studies which exclusively include child participants are especially warranted.

Thrombolytic therapy for central venous catheter occlusion

BACKGROUND

Long-term central venous catheters have improved the quality of care for patients with chronic illnesses, but are complicated by obstructions which can result in delay of treatment or catheter removal.

DESIGN AND METHODS

This paper reviews thrombolytic treatment for catheter obstruction. Literature from Medline searches using the terms "central venous catheter", "central venous access device" OR "central venous line" associated with the terms "obstruction", "occlusion" OR "thrombolytic" was reviewed. Efficacy of thrombolytic therapy, central venous catheter clearance rates and time to clearance were assessed.

RESULTS

Alteplase, one of the current therapies, clears 52% of obstructed catheters within 30 min with 86% overall clearance (after 2 doses, when necessary). However, newer medications may have higher efficacy or shorter time to clearance. Reteplase cleared 67-74% within 30-40 min and 95% of catheters overall. Occlusions were resolved in 70 and 83% of patients with one and 2 doses of tenecteplase, respectively. Recombinant urokinase cleared 60% of catheters at 30 min and 73% overall. Alfimeprase demonstrated rapid catheter clearance with resolution in 40% of subjects within 5 min, 60% within 30 min, and 80% within 2 h. Additionally, urokinase prophylaxis decreased the incidence of catheter occlusions from 16-68% in the control group to 4-23% in the treatment group; in some studies, rates of catheter infections were also decreased in the urokinase group.

CONCLUSIONS

Thrombolytic agents successfully clear central venous catheter occlusions in most cases. Newer agents may act more rapidly and effectively than currently utilized therapies, but randomized studies with direct comparisons of these agents are needed to determine optimal management for catheter obstruction.

Upper Extremity Deep Vein Thrombosis: The Oft-forgotten Cousin of Venous Thromboembolic Disease

OPINION STATEMENT

Upper extremity deep venous thrombosis (UEDVT) accounts for between 4% and 10% of all deep venous thromboses, and may be due to primary or secondary causes. The incidence of UEDVT is increasing, partly due to the exponential growth in the use of central venous catheters and the increasing placement of permanent cardiac pacemaker or defibrillator devices. UEDVT not only compromises future vascular access but results in significant morbidity and mortality, with symptomatic pulmonary embolus occurring in approximately 12%, post-thrombotic syndrome in 13%, and mortality ranging from 15-50%. Treatment of UEDVT depends on the underlying cause, primary or secondary. In this review, we will evaluate the management options and present a proposed treatment algorithm for primary UEDVT, involving catheter-directed thrombolysis, selective use of mechanical thrombectomy, anticoagulation and antithrombotic therapy, expeditious early first rib resection to decompress the thoracic outlet, and the role of adjunctive endovascular balloon angioplasty and stenting in improving axillo-subclavian vein patency. With regard to secondary UEDVT, we will present a treatment algorithm for managing central venous catheter (CVC) thrombosis; review the options for antithrombotic and anticoagulant therapy; and discuss the role of endovascular therapy. Finally, we will review the data supporting the growing role of percutaneous transluminal angioplasty (PTA) or venoplasty and endovascular stenting as the modality of choice in managing SVC obstruction, whether due to benign or malignant causes, and provide a brief description of the role, benefits and potential complications of SVC filter placement.

Clinical utility of novel agents in the treatment of central venous catheter occlusion

Central venous catheter (CVC) occlusion occurs frequently and remains a significant clinical problem in patients with cancer receiving infusional or intravenous chemotherapy. Thrombotic occlusions frequently limit the benefits of potentially curable cytotoxic agents by interrupting the delivery of infusion of chemotherapy, intravenous medication, nutritional support, and blood products, as well as the frequent acquisition of venous blood samples for laboratory testing. Urokinase has been used as a thrombolytic agent for dysfunctional occluded CVCs, but the alterations in manufacturing practice prompted the Food and Drug Administration to suspend further production of urokinase in 1999. Although streptokinase had a potential as a thrombolytic agent in place of urokinase, the risk of life-threatening anaphylaxis associated with this agent prompted researchers to look for newer agents to dissolve CVC occlusions. Several novel thrombolytic agents are currently being evaluated as a potential treatment for patients with CVC occlusions and acute or chronic peripheral arterial occlusions. Alfimeprase, a recombinant fibrinolytic zinc metalloprotease, has shown promising clinical utility in blood clot lysis in patients with CVC occlusions and peripheral arterial occlusions. Based on the encouraging data, alfimeprase has received orphan drug designation from the Food and Drug Administration and the Committee for Orphan Medicinal Products of the European Medicines Agency for the evaluation of acute peripheral arterial occlusions as a potential indication. Other novel thrombolytic agents such as alteplase and reteplase are undergoing clinical evaluation for their utility in restoring the function of occluded CVCs. The clinical potency of these novel agents and their ongoing clinical trials are discussed briefly herein.

[Complications of venous port systems : Radiological diagnostics and minimally invasive therapy]

INTRODUCTION

Documentation of a correct port placement is a routine investigation in radiology. This article describes typical complications of port catheters and minimally invasive treatment options which can guarantee further use without complications.

MATERIAL AND METHODS

From January 2009 to May 2010 a surgical port placement was carried out on 174 patients at the University Clinic in Mannheim and of these, 52 patients were admitted to our institute for radiological imaging of the port. Minimally invasive treatment options are presented based on the observed port complications.

RESULTS

Of the 52 patients 7 (13.5%) received a port catheter lysis. A successful port position correction was carried out in 3 (5.8%) patients with a malpositioned port catheter and port removal was recommended in 2 patients (3.8%) due to extensive arm venous thrombosis. A minimally invasive port catheter treatment allowed further use of the port system without operative revision in the corresponding patients. The measures were tolerated very well by the patients without postinterventional complications.

Upper extremity deep venous thrombosis

Upper extremity deep venous thrombosis is a serious disease entity which, based on the pathogenesis and in view of the individual patient’s prognosis, must be divided into a primary and a secondary form. Primary upper extremity deep venous thrombosis is, when related to effort, a rather benign disease with excellent prognosis quoad vitam, carrying only a minor potential of developing disabling post-thrombotic syndrome. If primary upper extremity deep venous thrombosis occurs without any obvious cause, screening for underlying malignancy is recommended. Secondary upper extremity deep venous thrombosis typically occurs in older patients with severe comorbidities, mainly related to indwelling central venous catheters and cancer. As a consequence of the underlying diseases, prognosis of secondary upper extremity deep venous thrombosis is poor. Despite a lack of high-quality validation data, ultrasonography is regarded the first-line imaging technique, since it is a non-invasive method without exposure to radiation. In case of a non-diagnostic result of ultrasonography, other imaging modalities such as magnetic resonance imaging and computed tomography may be applied. Regardless of the etiology, the cornerstone of therapy is anticoagulant treatment with low molecular weight heparin or unfractionated heparin and vitamin K antagonists in order to prevent thrombus progression and pulmonary embolism. Owing to a lack of evidence, the optimal duration of anticoagulant treatment remains unclear. The additional benefit of compression therapy as well as of more aggressive therapeutic approaches such as thrombolysis, angioplasty and surgical decompression of the thoracic outlet needs to be investigated in randomized trials.

Prevention of dialysis catheter malfunction with recombinant tissue plasminogen activator

BACKGROUND

The effectiveness of various solutions instilled into the central venous catheter lumens after each hemodialysis session (catheter locking solutions) to decrease the risk of catheter malfunction and bacteremia in patients undergoing hemodialysis is unknown.

METHODS

We randomly assigned 225 patients undergoing long-term hemodialysis in whom a central venous catheter had been newly inserted to a catheter-locking regimen of heparin (5000 U per milliliter) three times per week or recombinant tissue plasminogen activator (rt-PA) (1 mg in each lumen) substituted for heparin at the midweek session (with heparin used in the other two sessions). The primary outcome was catheter malfunction, and the secondary outcome was catheter-related bacteremia. The treatment period was 6 months; treatment assignments were concealed from the patients, investigators, and trial personnel.

RESULTS

A catheter malfunction occurred in 40 of the 115 patients assigned to heparin only (34.8%) and 22 of the 110 patients assigned to rt-PA (20.0%)--an increase in the risk of catheter malfunction by a factor of almost 2 among patients treated with heparin only as compared with those treated with rt-PA once weekly (hazard ratio, 1.91; 95% confidence interval [CI], 1.13 to 3.22; P = 0.02). Catheter-related bacteremia occurred in 15 patients (13.0%) assigned to heparin only, as compared with 5 (4.5%) assigned to rt-PA (corresponding to 1.37 and 0.40 episodes per 1000 patient-days in the heparin and rt-PA groups, respectively; P = 0.02). The risk of bacteremia from any cause was higher in the heparin group than in the rt-PA group by a factor of 3 (hazard ratio, 3.30; 95% CI, 1.18 to 9.22; P = 0.02). The risk of adverse events, including bleeding, was similar in the two groups.

CONCLUSIONS

The use of rt-PA instead of heparin once weekly, as compared with the use of heparin three times a week, as a locking solution for central venous catheters significantly reduced the incidence of catheter malfunction and bacteremia. (Current Controlled Trials number, ISRCTN35253449.).

Does low-dose heparin maintain central venous access device patency?: a comparison of heparin versus saline during a period of heparin shortage

BACKGROUND

A common problem that complicates use of central venous access devices (CVADs) is occlusion by thrombosis. Alteplase, a recombinant tissue plasminogen activator, is used to restore line patency when thrombosis occurs. Heparin flush is commonly used to prevent this complication, but the effectiveness of this practice is unclear. A recent heparin shortage allowed examination of heparin effectiveness in reducing CVAD thrombosis.

METHODS

A retrospective cohort study was performed by querying a pharmacy database for alteplase use for CVAD thrombosis in adult patients during periods when heparin flushes (10 units/mL) were used and when saline flushes were used instead because of a nationwide heparin shortage. The number of patients receiving alteplase, the number of doses administered, and the total amount of alteplase used were compared over 1-month intervals of heparin flush use and 1-month intervals of saline flush use. Patient days and critical care patient days were compared between these time intervals. Peripherally inserted central catheter (PICC) line placements and replacements between time periods of heparin and saline flush were also compared.

RESULTS

Significant increases in the number of patients receiving alteplase (P = .04), the number of alteplase doses administered (P = .04), and total dose of alteplase used (P = .05) occurred during the heparin shortage. No significant differences in patient population were observed. The percentage of PICC line replacements also increased significantly (P < .05) when heparin was not available.

CONCLUSIONS

Heparin flush (10 units/mL) decreases thrombotic occlusions of CVADs, resulting in decreased alteplase use and fewer PICC line replacements.

Infectious and thrombotic complications of central venous catheters

OBJECTIVE

To provide a review of the pathogenesis, prevention, and management strategies of infectious and thrombotic complications of central venous access devices (CVADs).

DATA SOURCE

Journal articles, case reports, product information, personal experience, professional guidelines.

CONCLUSION

Infectious and thrombotic catheter-related complications are common and serious complications that can negatively impact patient outcomes. There has been significant national attention on patient safety, and in particular, the prevention of catheter-related bloodstream infections.

IMPLICATIONS FOR NURSING PRACTICE

Clinicians have a crucial role in preventing and identifying CVAD-related complications. Understanding the pathogenesis of infectious and thrombotic complications, the principles of best practice, and adhering to these practices consistently, in all practice settings, are critical in order to minimize unnecessary risks to patients with an indwelling CVAD.

Hematological issues in critically ill patients with cancer

Patients with solid and hematologic malignancies presenting with major bleeding or thrombotic complications, potentially life-ending events in a cancer patient's clinical course, usually require admission to an intensive care unit (ICU), making their diagnosis and management even more important for the intensivist. Given the significant advances in the diagnosis and treatment of almost all types of cancers in recent years, the intensivist is likely to encounter an ever-increasing number of cancer patients in the ICU setting with these complications. Abnormal hemostasis can occur as a consequence of both the pathology and treatment of cancer. Because cancer can have multiple effects on hemostatic equilibrium, treatment of these complications can be more complex than in the general population. This article reviews the physiology of coagulation and fibrinolysis, with special attention to those aspects that are most frequently altered in the setting of malignancy. The pathophysiology of bleeding and thrombotic complications specific to critically ill cancer patients are then detailed, and the diagnostic and therapeutic strategies are discussed. Special emphasis is placed on new cancer medications that have an effect on hemostasis, and on novel clotting and anticoagulant agents that are available to the intensivist for the management of these patients.

Efficacy of local instillation of recombinant tissue plasminogen activator for restoring occluded central venous catheters in neonates

OBJECTIVE

To evaluate the efficacy of local instillation of tissue plasminogen activator (tPA) for restoring function to occluded central venous catheters (CVCs) in the neonatal population.

STUDY DESIGN

This was a retrospective review of patients admitted to the neonatal intensive care unit during September 2000 to April 2006 who received instillation of tPA for occluded CVCs.

RESULTS

Among 18 infants who received tPA for occluded CVCs, gestational age at birth was 32.5 weeks, birth weight was 1550 g, and gestational age at tPA administration was 39 weeks, with 4 neonates < or =32 weeks' gestational age at tPA administration; age at tPA use was 39 days (medians reported). Ten of 18 (55%) of CVC occlusions were successfully opened after using tPA. No bleeding complications of tPA were noted, including increased or new-onset intraventricular hemorrhage, overt bleeding, or changes in INR or partial thromboplastin time attributed to tPA use. Three patients (16.5%) had bacteremia within 7 days of tPA administration, and no catheter ruptures occurred.

CONCLUSIONS

Local instillation of tPA was successful in restoring function to occluded CVCs in a significant proportion of neonates, although success rates were lower than that reported in populations of older age. Despite the vulnerability of neonates to the potential complications of tPA, no major complications were detected even among premature infants.

Pilot study of Alteplase (tissue plasminogen activator) for treatment of urinary clot retention in an in vitro model

INTRODUCTION

The management of urinary clot retention and hematuria involves manual irrigation with sterile water or normal saline via a Foley catheter followed by continuous bladder irrigation. Irrigation may become difficult because of the formation of dense blood clots. Tissue plasminogen activator (t-PA/Alteplase) may be a useful pharmacological agent to improve the efficacy of manual irrigation of large, dense clots. The goal of the current study was to compare t-PA to sterile water for clot irrigation in an in vitro model.

MATERIALS AND METHODS

In vitro models of clot retention were created using 500-cc urinary leg bags each filled with 80 cc of unpreserved whole blood from a healthy volunteer. Each model was incubated at 25 degrees C for 24 hours to allow clot formation. Four models each with 25 mL solution of t-PA at concentrations of 2, 1, 0.5, and 0.25 mg/mL were evaluated and compared to a control (25 mL sterile water). Models were instilled with solution (t-PA or control) and incubated for 30 minutes at 37 degrees C, and then irrigated with sterile water via 18F Foley by a blinded investigator. Three separate experiments were conducted, and statistical analysis was performed comparing various irrigation parameters.

RESULTS

Clot evacuation with 25 mL of t-PA at a concentration of 2 mg/mL (50 mg) was significantly easier (p = 0.05) and faster (p < 0.05) than the sterile water control. The mean time for clot evacuation in this model was 2.7 minutes for t-PA solution 2 mg/mL versus 7.3 minutes for the control (p < 0.05). Compared to the control, irrigation with t-PA solution 2 mg/mL also required less irrigant (180 mL vs. 500 mL) (p < 0.05) for complete evacuation. There was a similar trend in efficacy for the lower doses of t-PA, but this was not statistically significant.

CONCLUSION

In this in vitro study, a single 25 mL instillation of t-PA solution 2 mg/mL is significantly better than sterile water alone for clot evacuation. In vivo animal studies are pending.

Management of occlusion and thrombosis associated with long-term indwelling central venous catheters

Long-term central venous catheters (CVCs) are important instruments in the care of patients with chronic illnesses, but catheter occlusions and catheter-related thromboses are common complications that can result from their use. In this Review, we summarise management of these complications. Mechanical CVC occlusions need cause-specific treatment, whereas thrombotic occlusions usually resolve with thrombolytic treatment, such as alteplase. Prophylaxis with thrombolytic flushes might prevent CVC infections and catheter-related thromboses, but confirmatory studies and cost-effectiveness analysis of this approach are needed. Risk factors for catheter-related thromboses include previous catheter infections, malposition of the catheter tip, and prothrombotic states. Catheter-related thromboses can lead to catheter infection, pulmonary embolism, and post-thrombotic syndrome. Catheter-related thromboses are usually diagnosed by Doppler ultrasonography or venography and treated with anticoagulation therapy for 6 weeks to a year, dependent on the extent of the thrombus, response to initial therapy, and whether thrombophilic factors persist. Prevention of catheter-related thromboses includes proper positioning of the CVC and prevention of infections; anticoagulation prophylaxis is not currently recommended.