Predisposing factors, prevention, and management of central venous catheter occlusions.

Occlusion is the most common noninfectious complication of central venous access catheters. The primary approach is prevention. Successful management begins with an understanding of the potential etiologies of occlusions. Proper assessment aids the clinician in correctly identifying the cause and treatment strategy. This article focuses on the physiologic principles of, research on, and current clinical practices with central venous catheter occlusions.

Central venous catheter occlusion: successful management strategies.

Catheter occlusion is the most common noninfectious complication seen with longterm central venous access devices. Medical-surgical nurses frequently encounter these devices both in the hospital and home and are in a key position to recognize catheter occlusions and institute appropriate treatments. The etiology of catheter occlusion, its clinical evaluation, prevention, and treatment strategies will be reviewed.

Central venous access--catheters, technology, and physiology.

Medical-surgical nurses increasingly encounter central venous access devices. Effective patient care involves both the routine management of these devices as well as identifying potential complications and appropriate treatments. The key physiologic principles research, and clinical practices associated with vascular access technologies are presented.

Elimination of intraluminal colonization by antibiotic lock in silicone vascular catheters.

An in vitro model was designed to evaluate the efficacy of instilled antimicrobials to reduce or eliminate intraluminal microbial colonization. Minimal inhibitory concentration and minimal bactericidal concentration activity of appropriate test anti-infectives were determined using standard methodology against clinically derived and reference test strains commonly associated with catheter-related infection. Drug activity was validated by bioassay for the test anti-infectives. Reference and clinical test strains were inoculated to the intraluminal surface of silicone catheter segments and incubated for 30 min, after which the inoculum was replaced with total parenteral nutrition (TPN) solution and reincubated for 12 h. For 7 d, instillation of antibiotic and TPN solution was alternated every 12 h to simulate clinical conditions. On days 1, 4, and 7, catheter segments were rinsed, bisected, and sonicated for quantitative plate count to determine mean microbial counts per centimeter of catheter surface. Catheter segments were also prepared for scanning electron microscopy. A significant decrease in staphylococcal intraluminal colonization after instillation of nafcillin, ceftriaxone, gentamicin, and vancomycin was demonstrated (P < 0.001). Aztreonam, ceftriaxone, and gentamicin completely eliminated gram-negative catheter colonization (P < 0.001). Yeast was eradicated from the internal catheter surface after treatment with amphoteracin B, and fluconazole significantly decreased intraluminal colonization (P < 0.001). Results show a significant decrease in staphylococcal, gram-negative, and fungal intraluminal colonization after instillation of appropriate antimicrobial. In vitro results support early clinical success using this technique. Future studies are warranted to identify optimal drug concentrations and dosing intervals.

Catheter pinch-off syndrome: recognition and management.

Catheter pinch-off syndrome is an uncommon and often unrecognized complication of central venous catheters. The cause, clinical diagnosis, and management of this unique catheter occlusion are reviewed. Nurses can play a key role in the early detection of catheter pinch-off syndrome as well as the prevention of subsequent catheter fracture and embolization.

Central venous access. Clinical practice issues.

Central venous catheterization has facilitated the delivery of parenteral nutrition for over 20 years. Current practice in the care of central venous catheters and management of associated complications reflects past clinical experience and innovative research study. The article highlights key issues associated with central venous access from a clinical perspective.

Treatment of Hickman catheter sepsis using antibiotic lock technique.

Antibiotic lock therapy, an alternative treatment for Hickman catheter sepsis, was evaluated in six recipients of prolonged outpatient intravenous therapy. Twenty-two episodes of catheter sepsis were identified, involving coagulase-negative staphylococci (11), gram-negative bacilli (3), gram-positive bacilli (1), yeast (4), and mixed bacteria or fungi (3). In a select group of patients, treatment was successful 92% of the time.

Pinch-off syndrome: a rare etiology for central venous catheter occlusion.

BACKGROUND: Catheter pinch-off syndrome is a rare and often misdiagnosed complication of tunneled Silastic central venous catheters. Pinch-off syndrome occurs when the catheter is compressed between the first rib and the clavicle, causing an intermittent mechanical occlusion for both infusion and withdrawal. We report its incidence in a large series of catheter insertions and describe the clinical presentation, radiographic findings, and recommended treatment. METHODS: A total of 1457 tunneled Silastic central venous catheters that were inserted using the percutaneous subclavian approach were prospectively studied. Indications for catheter placement included bone marrow transplant, continuous or intermittent chemotherapy, long-term antibiotics, and parenteral nutrition. Catheters were evaluated for clinical presentation of an occlusion relieved by postural changes and radiographic findings of luminal narrowing. RESULTS: Pinch-off syndrome was identified in 16 (1.1%) catheters. Radiographic findings were present in all catheters; clinical findings were present in 15 catheters. Clinical symptoms presented within a median of 2 days after placement (range, 0 to 167 days). Partial or complete catheter transection, a serious sequela of catheter pinch-off syndrome, occurred in 19% of the identified catheters. CONCLUSIONS: (1) Catheter pinch-off syndrome presents clinically as a catheter occlusion related to postural changes; (2) clinical symptomatology should be confirmed radiographically; and (3) catheter removal with a more lateral replacement in the subclavian vein or in the internal jugular vein will avoid a recurrent complication.

Nutrition support in specific diseases: back to basics.

The nutrition care of a patient is complicated by the recent proliferation of commercially available specialty products. Rational and objective guidelines are necessary to direct formula selection for use in specific diseases. Consideration of the patient's nutritional status, functioning of major organ systems, and alterations in nutrient metabolism are essential. The diagnosis of a specific disease does not necessitate the use of a specialty product in all instances. Many times modification of a standard formula can result in safe and effective nutrition. Basic nutrition principles should continue to guide the clinician as the definitive answers to the issues surrounding metabolic support in patients with specific disease states become available.

Glucose response to abrupt initiation and discontinuation of total parenteral nutrition.

Plasma glucose was studied during the initiation of total parenteral nutrition (TPN) and the discontinuation of TPN without a tapering schedule. Blood was sampled every 5 minutes for 2 hours after the start of TPN and 1 week later as TPN was discontinued. A total of 14 initiations and 14 discontinuations were studied in 18 patients. Severity of illness in patients ranged from stable condition postoperatively to multiple-system failure; six patients had diabetes mellitus. The TPN solution was a 3:1 admixture that provided a caloric intake equal to 1.2 times the resting energy expenditure, with 40% fat and 60% carbohydrate calories. An average of 1963 kcal was provided per day (340 g of glucose, 79 g of fat). During the initiation phase, the mean increase in plasma glucose was 60 mg/dL. The increase for diabetic patients was 79 +/- 14 mg/dL compared with 52 +/- 23 mg/dL for the nondiabetics. During the discontinuation phase, the mean plasma glucose decreased 40 +/- 20 mg/dL; two patients with high concentrations of regular insulin (50 and 100 units) showed an increase in plasma glucose when the TPN was stopped. Plasma glucose returned to the preinfusion baseline after discontinuation. During both initiation and discontinuation, plasma glucose showed little change after the first 60 minutes. No clinical symptoms of hypoglycemia were observed. In conclusion, TPN as a 3:1 admixture can be safely started as full nutrition support and stopped abruptly without a tapering schedule. Plasma glucose response is rapid, predictable, and mostly complete within 60 minutes.

The substance abuser and home intravenous therapy: above all else, do no harm.

Home care therapy is being challenged by changes in patient populations and technologic advances. The selection of appropriate candidates for home intravenous therapy is a critical issue faced by health care professionals. This process is more complex when the patient has a history of intravenous drug abuse. The issues concern patient compliance, safety, ethics, and legal responsibilities. Safe care depends on the ability of the patient to demonstrate a predetermined level of competence with catheter use. The potential use of illicit drugs may influence the ability of the patient to be compliant. Ethical principles of the patient's autonomy and free choice are weighed against the health professional's sense of beneficence. Legal guidelines stress informed consent, standards of care, and adequate documentation. An exploration of each of these factors outlines the potential risks and benefits and provides a basis for making clinical judgments.

Pinch-off syndrome: a complication of implantable subclavian venous access devices.

Implantable central venous access devices placed via the subclavian vein may become obstructed by thrombosis, impingement against a vein wall, or compression between the clavicle and first rib. The latter has been termed pinch-off syndrome (POS). Eleven patients with POS were studied, including one whose catheter had fractured and one whose catheter had fragmented. They were compared with 22 matched control patients and 100 consecutive routine clinic patients. Each catheter was graded: 0 = normal, 1 = abrupt change in course with no luminal narrowing, 2 = luminal narrowing, and 3 = complete catheter fracture. POS was present in most (eight of 11) cases within 3 weeks after placement. A grade 1 catheter was common (33%) among control subjects, but grades 2 and 3 were uncommon (1%). Catheter fracture or fragmentation was seen in two of five cases with long-term (greater than 3 weeks) pinching (grade 2 catheter). The following conclusions were reached: Grade 2 represents significant catheter compression and the potential for serious complications. Grade 1 is of uncertain clinical significance, due to its high prevalence in control subjects.