Complications of intravenous feeding catheters

Long-Term Parenteral Nutrition: Problems with Venous Access

Long-term parenteral nutrition requires central venous access, often difficult in patients who have had several central venous catheterizations. Therapy may be complicated by thrombosis and sepsis which may further compromise central access. We report five cases illustrating such difficulties and suggest that these patients be referred early to specialist centres where experienced catheter insertion and management results in a greatly reduced incidence of complications.

Transdermal Glyceryl Trinitrate to Allow Peripheral Total Parenteral Nutrition: A Double-Blind Placebo Controlled Feasibility Study

Seventy-two consecutive patients requiring total parenteral nutrition (TPN) were randomized to two groups. Group A received daily a peripheral intravenous regimen which provided 10 g nitrogen and 1400 non-nitrogen kcal (5.9 MJ). Group B received daily a peripheral intravenous regimen which delivered 9.4 g nitrogen and 1900 non-nitrogen kcal (8.0 MJ). Each group was further randomized to receive a self-adhesive patch of transdermal glyceryl trinitrate (GTN) or an identical placebo. Infusion survival was the main end-point. For group A, the median time of infusion survival was 74 h (range: 58–100) in the control group compared with 108 h (range: 68–156) in the group that received transdermal GTN (P < 0.001). For group B, the median infusion survival was 67 h (range: 46–92) in the control group compared with 103 h (range: 66–151) in the treatment group (P < 0.001). TPN is feasible via peripheral veins and the incidence of infusion failure can be effectively reduced by transdermal GTN.

Comparison of the Complications between Left Side and Right Side Subclavian Vein Catheter Placement in Patients Undergoing Coronary Artery Bypass Graft Surgery

Introduction: Percutaneous subclavian vein catheterization is one of the most common invasive procedures performed in cardiac surgery. The aim of this study was to compare left and right subclavian vein catheter placement via the infraclavicular approach in patients who undergo coronary artery bypass graft (CABG) surgery.

Methods: This prospective, randomized clinical trial was performed in193 patients. The technique applied for cannulation was infraclavicular approach for both the right and the left sides. Subclavian vein of other side was attempted only when catheterization at initial side was unsuccessful at two attempts. The success and complication rates were compared for the two sides.

Results: On193 patients, catheterization attempts were performed. Overall 177 catheterizations (91.7%) were successful during the first attempt, 105 (92.1%) on the right side and 72 (91.1%) on the left side. There was no significant difference between success rate and side of catheterization. Malposition of the catheter tip on the right side (9.6%) was significantly more than the left side (0%) (P= 0.003). The differences in other complications on two sides were statistically insignificant.

Conclusion: Compared with the right side, insertion of the cannula on the left side resulted in fewer catheter tip misplacements. Incidence of cannulation failure and other complications were similar on both sides.

Ethanol flush for the prevention of catheter occlusion

Catheter occlusion by lipid material has been associated with the use of compounded nutrient solutions containing lipid. We have studied the incidence of catheter occlusion when either a saline or an ethanol flush has been used prior to the application of a heparin lock following an overnight infusion of such nutrients. Lipid occlusion occured in 13 of 23 catheters when a saline flush preceeded the application of a heparin lock, whereas the use of a 20% ethanol solution before the application of the heparin lock resulted in only 2 occlusoins in 28 catheters (p < 0.001). In addition there was significantly longer catheter survival in the ethanol group (p < 0.01). It is concluded that an ethanol flush may significantly reduce the incidence of catheter occlusion during the use of lipid mixes.

Pseudomonas infection of the catheter exit site successfully managed with topical acetic acid

A case of recurrent catheter exit site infection with Pseudomonas aeruginosa is presented in a patient receiving home parenteral nutrition. The past episodes were managed by elective catheter replacement following extrusion of the catheter cuff. We describe the successful use of acetic acid to the exit site which resulted in the eradication of the organism and complete resolution of all signs.

A patient with jejunostomy liberated from home intravenous therapy after 14 years; contribution of balance studies

A patient with a jejunostomy 100 cm from the duodeno-jejunal flexure, following surgery for Crohn's disease, had needed parenteral fluids at home for 14 years because of a negative intestinal balance of sodium. Measurements were made of her oral intake and intestinal output during study periods each of 2 days. Loperamide 4 mg QDS, codeine phosphate 60 mg QDS and both together put her into positive intestinal fluid balance but sodium balance remained negative. Both drugs used together were more effective than either used alone. Ranitidine 300 mg BD made no significant difference to her intestinal output. 1 litre of a glucose-electrolyte solution (120 mmol sodium) sipped during the day resulted in sodium balance, but only with the addition of loperamide and codeine phosphate was positive sodium balance achieved (mean 44 mmol/day). This therapy allowed her to dispense with parenteral fluids which have been stopped for the last year.

Indwelling catheters and medical implants with FXIIIa inhibitors: A novel approach to the treatment of catheter and medical device-related infections

Central venous catheters (CVCs) are being utilized with increasing frequency in intensive care and general medical wards. In spite of the extensive experience gained in their application, CVCs are related to the long-term risks of catheter sheath formation, infection, and thrombosis (of the catheter or vessel itself) during catheterization. Such CVC-related-complications are associated with increased morbidity, mortality, duration of hospitalization, and medical care cost [1]. The present study incorporates a novel group of Factor XIIIa (FXIIIa, plasma transglutaminase) inhibitors into a lubricious silicone elastomer in order to generate an optimized drug delivery system whereby a secondary sustained drug release profile occurs following an initial burst release for catheters and other medical devices. We propose that the incorporation of FXIIIa inhibitors into catheters, stents, and other medical implant devices would reduce the incidence of catheter sheath formation, thrombotic occlusion, and associated staphylococcal infection. This technique could be used as a local delivery system for extended release with an immediate onset of action for other poorly aqueous soluble compounds.

Nutrition support teams: how they work, are set up and maintained

Safe cost effective nutritional support is provided by a multidisciplinary team whose activity is overseen by a Nutrition Steering Group that reports directly to the Hospital Trust Board. When a nutrition support team (NST) is first formed, a nutrition nurse specialist enables parenteral nutrition to be given safely. An NST needs to have a clearly agreed scope of practice and needs to be able to justify its presence in terms of quality and cost savings.

Pulmonary function in rats dying from long‐term parenteral nutrition

Infusion of Vamin or Intralipid causes death in a rat model of continuous parenteral nutrition. Morphological investigations have shown vascular injury and thrombus formation in the lungs. In this study, lung function in rats was examined before death due to parenteral nutrition. The rats were fed saline intravenously (group I); 100 mL kg(-1) day(-1) (controls); a 7% amino acid-glucose solution (Vamin-Glukos) (group II); 100 mL kg(-1) day(-1), or 20% fat emulsion (Intralipid) (group III); 40 mL kg(-1) day(-1). The infusion was stopped when the condition of the rats deteriorated. In a saline-perfused, isolated lung model, pulmonary arterial pressure (Ppa), transpulmonary pressure (Ptp), endothelial function, measured as inactivation of serotonin (bioassay), and the capillary filtration coefficient (CFC) were determined. Haematological parameters were also evaluated. Constant findings in group II and III were central thrombus formation, anaemia and thrombocytopenia. Ppa increased from 0.7 (0.04) kPa in group I to 1.4 (0.1) kPa and 1.7 (0.1) kPa in groups II and III, respectively (p<0.001). Inactivation of serotonin was reduced to 36% (2) in group II and 37% (2) in group III compared with 74% (5) in group I (p<0.002). CFC increased to 25 mg min(-1) (5) (group II) and 30 mg min(-1) (6) (group III) compared with 13 mg min(-1) (2) in controls (p=0.01). The study shows that major pulmonary hypertension and severe reduction of the endothelial function are present when rats deteriorate after infusion of parenteral nutrition substrates.

Percutaneous closure after inadvertent subclavian artery cannulation

Accidental insertion of an arterial sheath is an uncommon but potentially serious complication of jugular venous catheterization. When the subclavian artery is inadvertently cannulated, sheath removal can be complicated by significant hemorrhage due to its incompressible location. We report a case of inadvertent insertion of an 8 French sheath into the subclavian artery, which was successfully removed and the puncture site sealed with a collagen-based vascular closure device (Angio-Seal STS Plus). This averted an otherwise emergent open surgical procedure to remove the sheath and repair the subclavian artery in a high-risk patient.

Peripheral parenteral nutrition in geriatric wards

Poor nutritional status significantly contributes to morbidity and mortality in elderly. Malnutrition and denutrition are amenable to interventions aimed to improve outcomes in acute conditions so that nutritional support is frequently initiated during hospitalisation. If the enteral route remains the first evidence-based choice when the gut is functional, this approach may be difficult to perform in some "geriatric" situations like delirium, agitation, coma or pulmonary congestion. In the first days of the acute condition, when the patient is still stable, an alternative to the enteral route may also be considered. Although there is no evidence that parenteral nutrition is better than enteral nutrition, the peripheral intravenous route may be of interest especially when the enteral route is contraindicated. Moreover, the technique of peripheral parenteral nutition reduces central cannulation-related complications like pneumothorax. We emphasize here the place of this alternative method for a short duration nutritional support when supplement of caloric intake is needed. We discuss indications, a practical approach, our experience and analyze the evidences for this complementary nutritional support.

UNRESOLVED ISSUES IN DIALYSIS: Long-Term Management of the Tunneled Venous Catheter

Despite their propensity for significant complications, tunneled central venous catheters have become a common means of vascular access in the United States for patients requiring maintenance hemodialysis for end-stage renal disease (ESRD). Reasons for their use include advanced patient age, peripheral vascular disease (arterial and venous), late referral for creation of vascular access, and more importantly, the lack of an interdisciplinary service line on vascular access among vascular surgeons, radiologists, and nephrologists. This review article summarizes complications commonly encountered in dialysis patients who use tunneled central venous catheters for vascular access-mainly thrombosis, stenosis, and infection. Special attention is given to novel approaches for the prevention of catheter-associated infections. Effective prevention and timely treatment of common catheter-associated complications can reduce the substantial morbidity associated with the use of these devices. However, these measures should not detract from the goal of avoiding or limiting the long-term use of catheters, thereby optimizing vascular access management by ensuring the timely availability of functioning arteriovenous fistulas.

Cost savings of an adult hospital nutrition support team

OBJECTIVES

A hospital-based nutrition support team (NST) may need to demonstrate cost savings and quality benefits. The primary aim of this study was to determine whether an NST could show tangible cost savings (equipment, investigations, and medication costs) from managing patients considered for parenteral nutrition (PN). Secondary aims related to the quality issues of placement of PN catheters, catheter-related sepsis (CRS), duration of parenteral nutrition, and mortality.

METHODS

An NST was formed in 1999 and worked in all adult areas of a university hospital (Leicester Royal Infirmary). Comparative data about all patients given PN were collected for 2 consecutive years (a retrospective pre-NST year and a prospective NST year).

RESULTS

In the pre-NST year there were 82 PN episodes (54 patients), 665 PN days, and a CRS rate of 71% (seven infections/100 PN days). In the NST year, there were 133 referrals for PN but only 78 PN episodes (75 patients, 59% of referrals), 752 PN days, and a decreased overall CRS rate of 29% (three infections/100 PN days, P < 0.05) but a rate of 7% (0.6 infection/100 PN days) in the final 3 mo of the NST year. Tangible cost savings for the NST year were derived from 55 avoided PN episodes (42741 pounds sterlings) and 35 avoided CRS episodes (7974 pounds sterlings). Thirty-nine percent of PN catheters were inserted by the NST with no insertion-related complications. Competency-based training of ward nursing staff decreased the CRS rate. Mean duration of PN increased from 8 to 10 d (P not significant). In-hospital mortality for patients who had PN was 23 of 54 (43%) in the pre-NST year compared with 18 of 75 (24%) in the NST year (P < 0.05).

CONCLUSIONS

Although the number of PN days increased with an NST, tangible cost savings of 50715 pounds sterlings were demonstrated within the NST year by avoided PN episodes and a decreased incidence of CRS. These savings justify the salaries of a nutrition nurse specialist and a senior dietitian.

Is the landmark technique safe for the insertion of subclavian venous lines?

BACKGROUND

The complications of central venous line insertion have been highlighted by the recent NICE report advising that ultrasound guidance should be used for central line insertion.

METHODS

We report a prospective audit of the complications of subclavian vein central venous line insertion for parenteral nutrition over a five-year period when ultrasound guidance was not used.

RESULTS

In total, 201 lines were inserted for parenteral nutrition into a subclavian vein. A single consultant surgeon inserted 120 of the lines and year five or six surgical registrars performed the other line insertions. Five pneumothoraces occurred in four patients who had subclavian lines inserted and a chest drain was required in three cases. Four line tips were found to be going upwards rather than into the superior vena cava. Misplacement was more common with right subclavian insertion. Inability to site the line at that attempt was associated with previous line insertion in four of six patients.

CONCLUSION

A low complication rate can be achieved for central line insertion for parenteral nutrition. It is likely that this is due to the small number of experienced operators.

Use of ethanol locks to prevent recurrent central line sepsis

Catheter-related sepsis (CRS) is a common complication of long-term parenteral nutrition. Conventional antibiotic therapy is often effective in the short-term but, because of poor activity against intraluminal microbial biofilms, may not prevent relapse. Ethanol is an effective antiseptic. We describe a case of a patient with recurrent CRS successfully treated with 70% ethanol locks.

Upper extremity deep venous thrombosis in patients with 5-fluorouracil-containing adjuvant chemotherapy--three case reports and a review

Catheter-related deep venous thrombosis is a complication that can occur in patients receiving chemotherapy. Three such cases are described and a review of the literature is made, focusing on recent results regarding possible thrombogenic mechanisms and the high prevalence of non-symptomatic thrombosis as well as the high morbidity and mortality associated with upper extremity deep venous thrombosis. Special emphasis is given to the cytotoxic effects of 5-fluorouracil on vascular endothelium and the likely link to thrombotic complications. The possible differences between two different methods of administering chemotherapy, continuous infusion and bolus dose administration, in this regard are briefly discussed. It is concluded that the first steps towards an understanding of the mechanisms behind the vascular effects of 5-fluorouracil have been taken. Much remains to be done before active interaction with the pathogenic processes leading to vascular and cardiac complications can be realized, yet various forms of anticoagulant therapy could well be an efficient form of prophylaxis.

Surface modification of a segmented polyetherurethane using a low-powered gas plasma and its influence on the activation of the coagulation system

A medical grade segmented polyetherurethane (PEU) was treated with a low-powered gas plasma using O(2), Ar, N(2) and NH(3) as the treatment gases. Changes in the surface functional group chemistry were studied using X-ray photoelectron spectroscopy. The wettability of the surfaces was examined using dynamic contact angle measurements and the surface morphology was evaluated using atomic force microscopy. The influence of the surface modification to the polyurethane on the blood response to the polyetherurethane was investigated by measuring changes in the activation of the contact phase activation of the intrinsic coagulation cascade. The data demonstrate that the plasma treatment process caused surface modifications to the PEU that in all cases increased the polar nature of the surfaces. O(2) and Ar plasmas resulted in the incorporation of oxygen-containing groups that remained present following storage in an aqueous environment. N(2) and NH(3) plasmas resulted in the incorporation of nitrogen-containing groups but these were replaced with oxygen-containing groups following storage in the aqueous environment. In all plasma treatments there was a lowering of contact phase activation compared to the untreated surface, the N(2) and NH(3) treatments dramatically so.

Randomized clinical trials to determine the role of topical glyceryl trinitrate in peripheral intravenous nutrition

BACKGROUND

The contribution of glyceryl trinitrate (GTN) to prevention of peripheral vein thrombophlebitis (PVT) during peripheral intravenous nutrition delivered by fine-bore midline intravenous catheter is unclear. The aim of this study was to establish its role.

METHODS

Two consecutive randomized clinical trials were conducted. In trial 1 patients were randomized to receive standard peripheral intravenous nutrition containing heparin and hydrocortisone with or without the placement of a topical GTN patch (triple therapy or dual therapy). In trial 2 patients were randomized to receive standard peripheral intravenous nutrition with either dual therapy or topical GTN alone (monotherapy).

RESULTS

Dual therapy was as effective as triple therapy in preventing PVT (incidence 10 of 37 versus 11 of 39 patients respectively). Dual therapy reduced the incidence and increased the time to onset of PVT compared with monotherapy (14 of 41 versus 22 of 35 patients respectively, P = 0.012; median 17.3 (95 per cent confidence interval (c.i.) 13.4 to 21.1) versus 8.9 (95 per cent c.i. 6.7 to 11.0) days, P = 0.007).

CONCLUSION

Use of a topical GTN patch confers no benefit when peripheral intravenous nutrition is delivered via a fine-bore midline intravenous catheter.

Transpleural subclavian central venous catheter placement in a child with scoliosis discovered during a thoracotomy

Placement of central venous catheters in dysmorphic children can be difficult because of distortion of normal anatomical landmarks. We present such a case of a 16 year-old child who had a central venous catheter inserted in the left subclavian vein. Although a conventional roentgenogram was consistent with correct placement, the catheter was found to traverse the pleural space before entering the subclavian vein.

Sleeve-related thrombosis: a new form of catheter-related thrombosis

In a detailed study of central venous catheter-related sleeve and thrombosis in experimental animals, a new form of thrombosis was detected and termed sleeve-related thrombosis. A silastic catheter was placed in the jugular vein and the anterior vena cava of 22 rabbits and 54 rats. After intervals of 1, 3, 7 days, 2, 3, 4 weeks and 1, 2, 4, 6 months the veins were examined by light microscopy and by transmission electron microscopy. In about 50% of the rats a thrombus was observed at the end of the catheter sleeve. Consecutive cutting allowed the visualization of a transition from a sleeve via part of sleeve and part of thrombus to a pure thrombus. This thrombus was separated from the vein wall and could not be considered a mural thrombus. As the thrombus was only attached to the terminal part of the organized catheter sleeve we propose the name sleeve-related thrombosis.

Use of the gonadal vein in children with difficult central venous access: a novel technique

In children who require multiple central venous catheterization, the commonly used veins can become thrombosed making central venous access a challenging problem. The authors report on a patient with a rare metabolic disorder who had extensive thrombosis of the superior vena cava and iliofemoral veins, in whom the right ovarian vein was cannulated using a retroperitoneal approach for the placement of a SILASTIC((R)) (Dow Corning, Midland, MI) catheter with an implantable port. This is a useful and reliable technique in children who have difficult venous access.

Complications and cost associated with parenteral nutrition delivered to hospitalized patients through either subclavian or peripherally-inserted central catheters

BACKGROUND AND AIMS

Total parenteral nutrition (TPN) is typically delivered through catheters inserted into the superior vena cava (SVC) via a subclavian or internal jugular vein approach. A peripherally-inserted central venous catheter (PICC), utilizing a cephalic or basilic venous approach, may provide a safe alternative to the standard catheter approach and, because non-physician providers can insert the PICC, may introduce a potential cost-savings to health care institutions. We sought to determine if PICC lines are safer and more cost-effective than the standard central venous catheter approach for hospitalized patients who require TPN.

METHODS

One hundred and two hospitalized patients (age range, 18-88 years) who required TPN were prospectively randomized to receive therapy via a centrally-inserted subclavian catheter (n=51) or a peripherally-inserted PICC line (n=51). The primary end-point was the development of a complication requiring catheter removal. Other end-points included catheter infection and thrombophlebitis. Cost associated with insertion and maintenance of each catheter was also studied.

RESULTS

Complication-free delivery rate (without the need to remove or replace the catheter) was 67% for subclavian catheters and 46% for PICC lines (P<0.05). The overall infection rate was 4.9 per 1000 catheter days and was similar for each catheter type (P=0.68). PICC lines were associated with higher rates of clinically-evident thrombophlebitis (P<0.01), difficult insertion attempts (P<0.05), and malposition on insertion (P<0.05). No catheter complications resulted in significant long-term morbity or mortality. No significant difference was noted between the two catheter types in terms of aborted insertion attempts (P=0.18), dislodgement (P=0.12), or line occlusion (P=0.25). After standardizing costs for each hospital, the direct institutional costs for insertion and maintenance of PICC lines (US$22.32+/-2.74 per day) was greater than that for subclavian lines (US$16.20+/-2.96 per day;P<0.05).

CONCLUSION

PICC catheters have higher thrombophlebitis rates and are more difficult to insert into certain patients when compared to the standard subclavian approach for central venous access in hospitalized patients who require TPN. Because of this, PICCs may be less cost-effective than currently believed because of the difficulty in inserting and maintaining the catheter.

How to feed patients with sepsis

Sepsis is associated with profound catabolism and hypermetabolism that complicate provision of nutritional support. These metabolic changes are caused by inflammatory mediators involved in the septic process and cannot be reversed by nutritional means. High protein isocaloric nutritional regimens are recommended if possible, in association with aggressive measures to control the sepsis. However, nutritional therapy and its complications may also affect the incidence and course of sepsis. Hyperglycemia and conventional intravenous fat emulsions have been shown to increase susceptibility to infection. Enteral nutrition is associated with fewer infectious complications than parenteral nutrition, at least in severely injured patients. Recently nutritional formulations have been introduced that contain novel substrates that enhance various aspects of immunity. Several studies have suggested that this immunonutrition reduces infection risk in the critically ill, and preliminary findings suggest it may even have an effect on survival in sepsis.

Ultrasonic investigation of the effect of topical glyceryl trinitrate on peripheral arm vein diameter: implications for intravenous nutrition

BACKGROUND

It has been suggested that topical glyceryl trinitrate (GTN) ointment may cause venodilatation and hence deter thrombophlebitis. However, objective evidence of an increase in vein diameter has not been demonstrated.

METHODS

B mode ultrasonography was used to measure arm vein diameter. In a prospective study, measurements were taken before and after 24 hours of exposure to topical GTN.

RESULTS

Reproducibility of vein diameter measurement was demonstrated. Basilic veins were larger than cephalic veins, but exposure to GTN ointment for 24 hours was not associated with measurable venodilatation.

CONCLUSIONS

Ultrasonography enabled noninvasive measurement of intraluminal vein diameter. It is unlikely that GTN prevents thrombophlebitis in superficial arm veins by causing venodilatation.

Nutrition and inflammatory bowel disease

This article reviews the nutritional aspects of inflammatory bowel disease (IBD) including the mechanisms and manifestations of malnutrition and the efficacy of nutritional therapies. Nutrient deficiencies in patients with IBD occur via several mechanisms and may complicate the course of the disease. Nutritional status is assessed by clinical examination and the use of nutritional indices such as the Subjective Global Assessment of nutritional status. Nutritional intervention may improve outcome in certain individuals; however, because of the costs and complications of such therapy, careful selection is warranted, especially in patients presumed to need parenteral nutrition.

Incidence of vein thrombosis in peripheral intravenous nutrition: effect of fat emulsions

The relative risk of thrombophlebitis induced by either Long-chain Triglycerides (LCTs) or Medium-chain Triglycerides (MCTs) during peripheral i.v. nutrition (PIN) was evaluated. A total of 76 patients were randomly assigned into group A (n=40) and group B (n=36). The nutritional requirements in both groups were covered by a standardized regime of osmolality 1130 mOsm and pH 5.2, which provided 14 kg/day(-1) nitrogen, 600 kcal/day(-1) of carbohydrates and 1000 kcal/day(-1) of lipids. Group A received the lipids as pure LCTs while group B received a mixture of LCTs/MCTs at a ratio 1:1. The infused nutritional volume was 2000 ml and was delivered via a suitable vein in a proximal forearm, using a fine bore polyurethane 22G catheter. The two standardized regimes were evaluated over a 10 day period regarding the incidence of thrombophlebitis. The cumulative risk of thrombophlebitis was documented to be significantly lower in group A compared to group B (17.5% versus 44.4%, P < 0.05). LCTs appear to prolong peripheral vein feeding by lessening the reaction of venous endothelium to the irritating nutritional infusate.

Stability issues in home parenteral nutrition

Home parenteral nutrition (HPN) is a method of providing nutrients, fluid and electrolytes intravenously to patients with a malfunctioning gastrointestinal tract, at home. Parenteral nutrition (PN) formulations are checked carefully for stability by the hospital pharmacist before the bags are made. However, there are many differences between supplying PN regimens to in-patients on the ward and to patients at home. Transportation between the hospital and home may be prolonged if the patient lives a long way from the hospital and may not be straight-forward. A number of factors can adversely affect the stability of the PN, which in turn can cause complications such as line blockage; or even life-threatening events, such as pulmonary embolism. The hospital team caring for HPN patients needs to be aware of these stability issues if complications resulting from incompatibilities of the solutions in the bags or the infusion line are to be avoided.

[Economic impact of a prescription protocol in an intensive care unit]

OBJECTIVE

To assess the economic impact of a prescribing protocol for i.v. fluid therapy and artificial nutrition.

STUDY DESIGN

Comparative study, before and during use of the protocol.

PATIENTS

The study included 555 ICU patients allocated into two groups, before and after starting with the protocol. The groups were comparable for number, pathologies, age, severity score, duration of ICU stay, incidence of nosocomial infections, mortality rate.

METHOD

In February 1995, a written literature-based prescribing protocol for fluid therapy (hydroxyethylstarch and albumin), and artificial nutrition (enteral nutrition as first-line therapy) was devised. A cost analysis was made for two 6-month periods: before (August 1994 to January 1995) and after start of protocol (February to July 1995).

RESULTS

The prescription of albumin and hydroxyethylstarch decreased (by 33 and 58% respectively), whereas administration of Ringer lactate and gelatine solutes increased simultaneously. This induced a cost saving of 15,000 FF (a 20% decrease in cost). The reduction of parenteral nutrition in favour of early enteral nutrition induced a cost saving of 56,000 FF (31% decrease in cost).

CONCLUSION

Our prescribing protocol generated a cost saving of 9% of the pharmaceutical budget and decreased the cost-benefit ratio of our ICU.

Central venous catheter failure is induced by injury and can be prevented by stabilizing the catheter tip

PURPOSE

Thrombosis associated with central venous catheters is a significant cause of device failure, morbidity, and loss of access sites. We hypothesized that central vein thrombosis is caused by catheter injury to the vein wall and that it can be reduced by stabilizing the catheter tip. To test these hypotheses, we studied central vein catheters in a porcine model. Test catheters had a silicone-encased stainless steel loop at the indwelling end that contacted the vein wall and stabilized the catheter tip in the center of the vessel.

METHODS

Sealed silicon elastic (Silastic) catheters (3.2 mm outer diameter) with and without a stabilizing loop were inserted via the external jugular vein into the superior vena cava just above the right atrium. Animals were killed at 1, 2, 4, and 8 weeks, and the vena cava was inspected for the presence of thrombus and entrapment of the catheter tip.

RESULTS

In control animals mural thrombus developed at the site of the catheter tip. This thrombus organized by invasion of macrophages and smooth muscle cells, eventually forming a lesion similar to intimal hyperplasia. Lesion cross-sectional area was significantly smaller in animals with loop catheters than in control animals at 2 weeks (1.2 +/- 1.3 vs 34.5 +/- 23.9 mm2; p = 0.05) and 4 weeks (2.8 +/- 0.3 vs 13.9 +/- 5.8 mm2; p < 0.05). By 8 weeks the vena cava was nearly occluded in most animals and the catheter tip was entrapped in this lesion in all cases. Test catheters eliminated the injury process for up to 8 weeks (p < 0.01, chi2 control vs loop catheter entrapment). Very little injury response was found where the loop contacted the vein wall, and the catheter tip was free of thrombus in all cases.

CONCLUSIONS

Mural thrombosis at the tip of indwelling central catheters is caused by chronic mechanical venous wall injury. Vessel injury and the resulting thrombosis can be prevented by a catheter modification that stabilizes the tip. Such a catheter may significantly reduce catheter malfunction and morbidity associated with these devices.

Migration of jugular or subclavian venous catheters into inferior tributaries of the brachiocephalic veins or into the azygos vein, with possible complications

Six children are reported in whom a central venous catheter from the internal jugular or the subclavian vein migrated to an anomalous position: the left superior intercostal vein in the first two cases, the thymic vein in the third, and the azygos vein in the last three. Resultant complications in five cases were: extravasation of the infusate in the first and third case; local vascular stenosis or complete vascular occlusion in the second and fifth case; and obstruction of the azygos arch due to local thrombosis and possible stenosis, with a likely extravasation of the infusate, in the sixth case. The mediastinal vascular anatomy related to these central venous catheters is reviewed with reference to similar and related cases in the literature.

High osmolality feedings do not increase the incidence of thrombophlebitis during peripheral i.v. nutrition

BACKGROUND

Peripheral i.v. nutrition has been advocated for patients who require short-term i.v. nutrition support to avoid the complications and expense of central venous catheterization. Feeding formulas for peripheral administration have usually been modified by increasing the proportion of lipid, because increasing osmolality is reported to cause thrombophlebitis. The aim of this study was to determine whether standard feeding formulas can be given via the peripheral route and also to establish whether increasing osmolality does increase the incidence of thrombophlebitis under these conditions.

METHODS

Thirty-six patients requiring parenteral nutrition were randomized to receive either a "high" (1700 mOsmol/L) or "standard" (1200 mOsmol/L) osmolality feeding containing 2000 kcal and 12 g nitrogen via a peripheral line.

RESULTS

Twenty patients (mean age 55.6 years, range 16 to 78) received standard osmolality feedings using 20 peripheral feeding lines for a mean duration of 6.8 days (range 2 to 16) with 10 line failures (8 thrombophlebitis, 2 occlusion). Nineteen patients (mean age 56.1 years, range 27 to 83) received high osmolality feedings via 20 lines for a mean of 6.3 days (range 0 to 18) with five line failures (4 thrombophlebitis, 1 occlusion), one failed insertion, one line removed at the patient's request, and four lines that fell out. Forty lines were inserted overall of which 19 (47.5%) were removed electively, 12 (30%) developed thrombophlebitis, 3 (7.5%) occluded, 4 (10%) fell out, 1 (2.5%) was a failed insertion, and 1 (2.5%) was removed for nonmedical reasons.

CONCLUSIONS

Increasing osmolality of total parenteral nutrition did not increase episodes of thrombophlebitis in this trial and did not affect the success rate of the lines. We conclude that standard total parenteral nutrition formulas of higher osmolality than previously thought can be safely given via the peripheral route for short-term feeding and do not increase the risk of thrombophlebitis.

Peripheral infusion as the route of choice for intravenous nutrition: a prospective two year study

A central venous catheter (CVC) is widely regarded as the standard route for delivery of intravenous nutrition (IVN). Peripheral venous infusion avoids the morbidity of a CVC, but may require regular resiting of standard intravenous cannulae, or compromise of the nutritional quality of the feed, to avoid thrombophlebitis. Fine-bore catheters, designed for use in neonates, have been associated with a much lower incidence of phlebitis when used for peripheral IVN in adults, but reports have been limited to selected groups of patients. A prospective study of 302 courses of IVN is presented in which a peripheral vein was the route of first choice. The composition of the feed was determined by the patient's metabolic requirement, and was not compromised to facilitate peripheral venous infusion. In 51% of all courses of IVN the peripheral route alone was used; 76% of patients who received peripheral IVN required only one fine-bore catheter.

Fatal microvascular pulmonary emboli from precipitation of a total nutrient admixture solution

BACKGROUND

Paroxysmal respiratory failure and death occurred in two young adult females with pelvic infections. Autopsy revealed an amorphous material containing calcium obstructing the pulmonary microvasculature of each patient. Both patients received an identical total nutrient admixture (TNA) solution before their deaths.

METHODS

Infusion of TNA into an animal model was undertaken in an effort to reproduce the clinical effect. Laboratory investigation was also performed to isolate a precipitate and identify the factors contributing to precipitation.

RESULTS

A nonvisible precipitate containing calcium, phosphorus, and organic material was isolated from the TNA solution. Infusion of the formulation into healthy pigs resulted in sudden death within 4 hours. Alteration of the amino acid component, mix sequence, agitation technique, and mixing container influenced precipitate formation.

CONCLUSION

Pulmonary embolization of a precipitate containing calcium phosphate resulted in the death of two patients. The pH of the amino acid component, transient elevation of calcium and phosphorus concentrations during mixing, and the lack of agitation during automated preparation of the formulation were identified as the etiologic factors producing the fatal precipitate.

Prolonged peripheral parenteral nutrition with an ultrafine cannula and low-osmolality feed

Peripheral parenteral nutrition is an attractive alternative to centrally delivered parenteral nutrition because it obviates the need for central venous cannulation and its attendant complications. Some 45 consecutive patients were fed peripherally using a 22-G polyurethane catheter and a fat-based, low-osmolality feed. Of these patients, 36 were fed for a median of 8.5 (range 3-31) days without peripheral vein thrombophlebitis (PVT). Seven patients developed PVT after a median of 6 (range 5-7) days. The cumulative daily risk of PVT was 0.016 episodes per day. These results suggest that prolonged (more than 7 days) problem-free peripheral parenteral nutrition is possible.

Preventive effect of simultaneously infused lipid emulsion against thrombophlebitis during postoperative peripheral parenteral nutrition

A prospective, randomized study was conducted to determine whether simultaneous infusion of lipid emulsion with an amino acid-dextrose-electrolyte solution would reduce the incidence of thrombophlebitis (TP) during postoperative peripheral parenteral nutrition (PPN). Thirty patients who had undergone gastric resection for adenocarcinoma were randomly divided into two groups according to whether they were infused with 10% lipid emulsion (group A) or 5% glucose solution (group B) simultaneously with the amino acid-glucose solutions. The total osmolarity of the infusion solutions in each group was 853 mOsm/l. The incidence of complications due to TP, namely, redness and/or edema beneath the cannula insertion site and/or pain, was investigated. There were no differences in the background characteristics of the patients in groups A and B, except regarding concurrent resection of other organs (P = 0.03). The incidence of edema in group A was significantly lower than in group B on postoperative days 2 and 4, although there was no difference in the incidence of redness and pain between the two groups. These findings suggest that the simultaneous infusion of lipid emulsion has a preventive effect against TP during postoperative PPN, and may be a practical means of providing PPN after gastrointestinal surgery.

Central venous catheter sepsis with weekly catheter change in paediatric burn patients: an analysis of 221 catheters

To document the risk of catheter sepsis associated with central venous catheter changes every 7 days in paediatric burn patients, and analysis of data collected prospectively on 234 such catheters was performed. During an 18-month period there were 301 acutely burned children admitted to a regional paediatric burn facility of whom 53, with an average burn size of 42 per cent TBSA, required 234 central venous catheters. A central venous catheter management protocol was followed which included catheter changes every 7 days. If insertion sites were clean and uninflamed, catheters were replaced by guidewire and the original catheter tip was semiquantitatively cultured. Catheters were replaced to a new site if insertion sites appeared inflamed or catheter tips grew 15 or more colony forming units. Overall, 3.2 per cent (10.9 per cent by Centers for Disease Control definition) of central venous catheters were associated with sepsis. When catheters were replaced by guidewire from one to three times, catheter sites were used for a mean of 15.6 days without an increased rate of line sepsis. There was no difference in sepsis rates between catheters placed at a new site or replaced by guidewire. There were no deaths attributed to catheter-related sepsis. We conclude that a protocol allowing for catheter change to a new site, or replacement by guidewire, every 7 days was associated with a low risk of catheter sepsis in paediatric burn patients.

[Respective indications of enteral or parenteral nutrition during pre- and post-operative periods]

Denutrition is often associated with poor postoperative outcome. However, a large body of evidence, from studies comparing perioperative parenteral (PN) or enteral (EN) nutrition to the absence of perioperative nutrition, suggests that perioperative nutritional support provides significant improvements in both nutritional status and postoperative clinical outcome in selected patients who are or will become malnourished. The aim of this study was to select and review all relevant articles comparing perioperative parenteral and enteral nutritional support, either in terms of clinical outcome, or risks and costs, or in pathophysiological terms. Twelve clinical reports were reviewed. All contained methodological flaws, mainly type II statistical error due to an insufficient number of patients, inaccurate primary diagnosis, absence of blinding, and lack of objective criteria of judgement. These concerns warrant caution in interpreting the results. Moderately strong (grade B) recommendations can only be drawn from these studies: PN (compared to early EN) is associated with a higher rate of sepsis in patients following abdominal trauma; EN is as efficient as PN in patients following surgery; EN is safe and cheaper than PN. PN formulae lack many important nutrients (glutamine, arginine, cysteine, peptides, fibers, n-3 polyunsaturated fatty acids, and nucleotides). Many experimental (animal) and some clinical (in non surgical patients) studies showed that PN (compared to EN) induces gut mucosal atrophy, liver dysfunction, gut bacterial translocation and immune dysfunction. The final aim of PN and EN would therefore strikingly differ. The qualitatively imperfect PN would only supply the fasting patient with quantitative amounts of calories and proteins. Due to initially limited digestive tolerance, EN provides less nutrition than PN does, but would finally lead to the same or even better outcome, due to its ability to counteract stress induced gut and immune dysfunction. Current evidence therefore suggests that early EN is superior to PN in trauma patients, and not different from but cheaper (and therefore more cost-effective) than PN in surgical patients. Further controlled, randomised, and blinded studies including sufficient sizes of groups are required, especially in the surgical setting, to address a large number of still unanswered questions.