Peripheral versus central intravenous nutrition: comparison of two delivery systems

Use of parenteral nutrition in hospitals in the North of England

BACKGROUND

Parenteral nutrition (PN) is a costly technology used widely to provide nutrition to patients who have an inaccessible or nonfunctioning intestine. A prospective survey was designed to collect data on PN for inpatients to study the current use of PN, its complications and outcomes in the north of England. The study objectives were to use the Northern Nutrition Network to collect data from all acute hospital inpatients prospectively receiving PN, for 3 months and to provide evidence for current PN practice, and to establish whether this is in line with recognized published clinical guidelines.

METHODS

Using a paper-based collection tool information was recorded on aspects of PN including: total inpatient episodes, patient demographics, indications, duration, venous access used, complications, number returning to enteral feeding and mortality. The presence of a nutrition support team was also recorded.

RESULTS

Data on 193 patient PN episodes were recorded totalling 1708 patient days. The median age of the patients was 67 years. Of these, 158 (82%) were deemed to have a clear indication for PN using the indications cited in the NICE guidelines (http://www.nice.org.uk). The median duration of PN was 7 days (range 1-93). Thirty (16%) patients developed complications due to PN, 23 (12%) had catheter infections which were most common on medical wards. Thirty-nine (20%) patients died within 28 days of PN starting; no deaths were attributable to PN. A total of 118 (61%) patients returned to full enteral feeding. Only three hospitals had nutrition support teams, which had no significant effect on outcomes.

CONCLUSIONS

Parenteral nutrition practice in the north of England is generally in line with current guidelines, however, only three of 15 hospitals had nutrition support teams. Eighteen per cent of patients did not have a clearly documented indication for PN and 15% developed a complication, most often a catheter-related infection.

The risk of bloodstream infection in adults with different intravascular devices: a systematic review of 200 published prospective studies

OBJECTIVE

To better understand the absolute and relative risks of bloodstream Infection (BSI) associated with the various types of intravascular devices (IVDs), we analyzed 200 published studies of adults In which every device in the study population was prospectively evaluated for evidence of associated infection and microbiologically based criteria were used to define IVD-related BSI.

METHODS

English-language reports of prospective studies of adults published between January 1, 1966, and July 1, 2005, were identified by MEDLINE search using the following general search strategy: bacteremla [Medical Subject Heading, MeSH] OR septicemia [MeSH] OR bloodstream Infection AND the specific type of intravascular device (e.g., central venous port). Mean rates of IVD-related BSI were calculated from pooled data for each type of device and expressed as BSIs per 100 IVDs (%) and per 1000 IVD days.

RESULTS

Point incidence rates of IVD-related BSI were lowest with peripheral Intravenous catheters (0.1%, 0.5 per 1000 IVD-days) and midline catheters (0.4%, 0.2 per 1000 catheter-days). Far higher rates were seen with short-term noncuffed and nonmedicated central venous catheters (CVCs) (4.4%, 2.7 per 1000 catheter-days). Arterial catheters used for hemodynamic monitoring (0.8%, 1.7 per 1000 catheter-days) and peripherally inserted central catheters used in hospitalized patients (2.4%, 2.1 per 1000 catheter-days) posed risks approaching those seen with short-term conventional CVCs used in the Intensive care unit. Surgically implanted long-term central venous devices--cuffed and tunneled catheters (22.5%, 1.6 per 1000 IVD-days) and central venous ports (3.6%, 0.1 per 1000 IVD-days)--appear to have high rates of Infection when risk Is expressed as BSIs per 100 IVDs but actually pose much lower risk when rates are expressed per 1000 IVD-days. The use of cuffed and tunneled dual lumen CVCs rather than noncuffed, nontunneled catheters for temporary hemodlalysis and novel preventive technologies, such as CVCs with anti-infective surfaces, was associated with considerably lower rates of catheter-related BSI.

CONCLUSIONS

Expressing risk of IVD-related BSI per 1000 IVD-days rather than BSIs per 100 IVDs allows for more meaningful estimates of risk. These data, based on prospective studies In which every IVD in the study cohort was analyzed for evidence of infection by microbiologically based criteria, show that all types of IVDs pose a risk of IVD-related BSI and can be used for benchmarking rates of infection caused by the various types of IVDs In use at the present time. Since almost all the national effort and progress to date to reduce the risk of IVD-related Infection have focused on short-term noncuffed CVCs used in Intensive care units, Infection control programs must now strive to consistently apply essential control measures and preventive technologies with all types of IVDs.

The effect of heparin in peripheral intravenous nutrition via a fine-bore midline: a randomised double-blind controlled trial

BACKGROUND AND AIMS

Peripheral intravenous nutrition (PIVN) delivered via a finebore midline offers a viable alternative to central venous feeding. The major complication is the onset of peripheral vein thrombophlebitis (PVT). Feed additives such as heparin and hydrocortisone have been advocated in its prevention. Concern over the safety of heparin has prevented its widespread use; this study examines its true benefit.

METHODS

A randomised, double-blind trial comparing the addition of either, Heparin 1500 units or hydrocortisone 15 mg or a combination of the two to full intravenous nutrition (IVN) (2500 ml, 13 g of nitrogen, 1190 m0sm/k) was performed. All feeds were delivered via a finebore midline inserted via an antecubital fossa vein. Feeding was terminated in the event of complication or cessation of intended nutritional support.

RESULTS

One hundred and twenty-three episodes of feeding occurred in 110 patients. The incidence of peripheral vein thrombosis was similar in each group (Heparin 30% (12/41), hydrocortisone 33% (14/42), combination 31% (13/41) chi(2) test P>0.05). There was a significant difference in total catheter survival with the addition of heparin to the feeds, either alone (11 days (SEM 1.79) or in combination with hydrocortisone (11.7 days (SEM 1.39) compared with those receiving only hydrocortisone (6.9 days (SEM 0.73) P=0.002 and 0.030, respectively)).

CONCLUSION

When intravenous feeds are delivered in to a peripheral vein via a fine-bore midline, the addition of heparin to the feed extends the total period of feeding attainable.

Nutritional support in critical care patients

Malnutrition in the form of insufficient nutrient intake to support tissue metabolism undermines appropriate medical or surgical therapeutic management of a case. The major consequences of malnutrition in all patients are decreased immunocompetence, decreased tissue synthesis and repair, and altered intermediary drug metabolism. A practical goal is to begin nutritional support within 24 hours of the injury, illness, or presentation. There are only two methods by which nutrients can be supplied to the body: enteral and parenteral. General guidelines are presented to help establish a foundation.

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.

Intravenous lipid emulsions are the major determinant of coagulase-negative staphylococcal bacteremia in very low birth weight newborns

BACKGROUND

Intravenous lipid emulsions and the i.v. catheters through which they were administered were the major risk factors for nosocomial coagulase-negative staphylococcal (CONS) bacteremia among newborns in our neonatal intensive care units a decade ago. However, medical practice is changing, and these and other interventions may have different effects in the current setting.

OBJECTIVES

We determined the independent risk factors for CONS bacteremia in current very low birth weight newborns after adjusting for severity of underlying illness.

METHODS

We surveyed 590 consecutively admitted newborns with birth weights < 1500 g hospitalized in 2 neonatal intensive care units and conducted a case-control study in a sample of 74 cases of CONS bacteremia and 74 pairs of matched controls. Adjusted relative odds of bacteremia were estimated for a number of attributes and therapeutic interventions in 2 time intervals before CONS bacteremia: any time before bacteremia and the week before bacteremia.

RESULTS

Using conditional logistic regression to adjust for indicators of severity of illness, two procedures were independently associated with subsequent risk of CONS bacteremia at any time during hospitalization: i.v. lipids, odds ratio (OR) = 9.4 [95% confidence interval (CI) 1.2 to 74.2]; and any surgical or percutaneously placed central venous catheter, OR = 2.0 (95% CI 1.1 to 3.9). Considering only the week immediately preceding bacteremia, the independent risk factors were: mechanical ventilation, OR = 3.2 (95% CI 1.3 to 7.6); and short peripheral venous catheters, OR = 2.6 (95% CI 1.0 to 6.5).

CONCLUSIONS

During the last decade exposure to i.v. lipids any time during hospitalization has become an even more important risk factor for CONS bacteremia (OR = 9.4). Of these bacteremias 85% are now attributable to lipid therapy. In contrast the relative importance of intravenous catheters as independent risk factors has declined. Mechanical ventilation in the week before bacteremia has emerged as a risk factor for bacteremia.

Prospective study of the aetiology of infusion phlebitis and line failure during peripheral parenteral nutrition

Four techniques of administering peripheral parenteral nutrition (PPN) were examined prospectively to investigate the role of mechanical trauma in the development of infusion phlebitis. Patients in group 1 (n = 15) were fed via a standard 18-G Teflon cannula which was removed on completion of the infusion and was rotated to the contralateral arm every day. Group 2 patients (n = 15) had a similar catheter sited in each forearm simultaneously, with rotation of the side of infusion each day. Patients in group 3 (n = 17) had a 15-cm Silastic rubber catheter inserted into a forearm vein and a standard cannula sited in the contralateral forearm, with alternation of infusion each day. Those in group 4 (n = 13) had a fine-bore 23-G silicone catheter sited in one arm only. Patients in groups 1, 2 and 3 were fed over 12-h cycles and those in group 4 for a 24-h continuous cycle. A total of 408 patient-days of PPN were given. Mean duration of PPN in groups 1-4 was 7.5, 9, 5.5 and 5 days respectively. Infusion phlebitis was not recorded in patients who had a daily change of cannula (group 1), but occurred in four patients in group 2, eight in group 3 and eight in group 4. Phlebitis scores were 0, 9, 15 and 12 for groups 1-4 respectively. Severe phlebitis and line occlusion occurred more frequently in patients with a 15-cm catheter (group 3) and in those fed continuously over 24 h (group 4). These results suggest that mechanical trauma is an important factor in the aetiology of infusion phlebitis. This can be minimized by reducing the time for which the vein wall is exposed to nutrient infusion and by reducing the amount of prosthetic material within the vein.

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.

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.