Caregivers can also measure central venous pressure and other physiological variables through the central line. They are also longer and, as reflected by Poiseuille's law , require higher pressure to achieve the same flow, all other variables being equal. Central IV lines carry risks of bleeding, infection, gangrene , thromboembolism and gas embolism see Risks below.
Surrounding structures such as the pleura and carotid artery are also at risk of damage with the potential for pneumothorax or even cannulation of the artery. There are several types of central IV access, depending on the route that the catheter takes from the outside of the body to the vein. The PICC line is inserted through a sheath into a peripheral vein sometimes using the Seldinger technique or modified Seldinger technique, under ultrasound guidance, usually in the arm, and then carefully advanced upward until the catheter is in the superior vena cava or the right atrium.
This is usually done by measuring the distance to an external landmark, such as the suprasternal notch, to estimate the optimal length. An X-ray must be used to verify that the tip is in the right place when fluoroscopy was not used during the insertion. A PICC may have a single single-lumen tube and connector, two double-lumen or three triple-lumen compartments, each with its own external connector.
Power-injectable PICCs are now available as well. The insertion site requires better protection than that of a peripheral IV line, due to the higher risk of serious infection if bacteria travel up the catheter. However, a PICC poses less of a systemic infection risk than other central IV lines, because the insertion site is usually cooler and drier than the sites typically used for other central lines.
This helps to slow the growth of bacteria which could reach the bloodstream by traveling under the skin along the outside of the catheter. The chief advantage of a PICC over other types of central lines is that it is safer to insert with a relatively low risk of uncontrollable bleeding and essentially no risks of damage to the lungs or major blood vessels. Although special training is required, a PICC does not require the skill level of a physician or surgeon.
It is also externally unobtrusive, and with proper hygiene and care can be left in place for months to years if needed for patients who require extended treatment. The chief disadvantage is that it must be inserted and then travel through a relatively small peripheral vein which can take a less predictable course on the way to the superior vena cava and is therefore somewhat more time consuming and more technically difficult to place in some patients.
As a PICC travels through the axilla, it can also become kinked, causing poor function. While some central lines have their catheter pass through the skin and then directly into the vein, other central lines called "tunneled catheters" insert through the skin and then pass or "tunnel" a significant distance before inserting into the vein. This reduces the risk of infection, since bacteria from the skin surface are not able to travel directly into the vein.
These catheters are often made of materials that resist infection and clotting. These include the Hickman line or Broviac catheter. A port often referred to by brand names such as Port-a-Cath or MediPort is a central venous line that does not have an external connector; instead, it has a small reservoir that is covered with silicone rubber and is implanted under the skin.
Medication is administered intermittently by placing a small needle through the skin, piercing the silicone, into the reservoir. When the needle is withdrawn, the reservoir cover reseals itself. The cover can accept hundreds of needle sticks during its lifetime. It is possible to leave the ports in the patient's body for years; if this is done, the port must be accessed monthly and flushed with an anti-coagulant, or the patient risks it getting plugged up.
If it is plugged, it becomes a hazard as a thrombus will eventually form with an accompanying risk of embolisation. Removal of a port is usually a simple outpatient procedure; however, installation is more complex and a good implant is fairly dependent on the skill of the radiologist.
Ports cause less inconvenience and have a lower risk of infection than PICCs, and are therefore commonly used for patients on long-term intermittent treatment. A third type is a midline catheter which is inserted into a peripheral vein and advances through the vein, unlike a peripheral IV line, but falls short of emptying into a central vein.
A continuous infusion is primarily used to correct fluid and electrolyte imbalances. This is as opposed to intermittent infusion, when a patient requires medications only at certain times, such as secondary IV and IV push. The tubing from the bag of fluid being administered that connects to directly to the patient is called the primary tubing. Any additional IVs to be administered are connected to the primary tubing and are called secondary IV, or IV piggyback;  this is done instead of placing multiple catheters in the patient.
When administering a secondary IV medication, the primary bag is held lower than the secondary bag so that the secondary medication can flow into the primary tubing, rather than fluid from the primary bag flowing into the secondary tubing.
The fluid from the primary bag is needed to help flush any remaining medication from the secondary IV from the tubing into the patient. Some medications are also given by IV "push" or bolus. A syringe containing the medication is connected to an access port in the primary tubing and the medication is administered through the port. The syringe plunger is pressed slowly, if it might irritate the vein or cause a too-rapid effect. Certain medications, such as potassium, are never to be administered by IV push because the spike in medication in the blood from the IV push could be fatal.
Once a medicine has been injected into the fluid stream of the IV tubing, there must be some means of ensuring that it gets from the tubing to the patient. Usually this is accomplished by allowing the fluid stream to flow normally and thereby carry the medicine into the bloodstream; however, a second fluid injection is sometimes used, a "flush", following the injection to push the medicine into the bloodstream more quickly.
Substances that may be infused intravenously include volume expanders, blood-based products, blood substitutes, medications and nutrition. There are two main types of volume expander: Crystalloids are aqueous solutions of mineral salts or other water-soluble molecules.
Colloids contain larger insoluble molecules, such as gelatin. Blood is a colloid. The best way to determine if a person will benefit from fluids is by doing a passive leg raise followed by measuring the output from the heart. Medications may be mixed into the fluids mentioned above.
Compared with other routes of administration , such as oral medications , the intravenous route is the fastest way to deliver fluids and medications throughout the body. Certain types of medications can only be given intravenously, such as when there is insufficient uptake by other routes of administration such as enterally. Examples include intravenous immunoglobulin and propofol. A blood product or blood-based product is any component of blood which is collected from a donor for use in a blood transfusion.
Blood transfusions can be life-saving in some situations, such as massive blood loss due to trauma , or can be used to replace blood lost during surgery. Blood transfusions may also be used to treat a severe anaemia or thrombocytopenia caused by a blood disease. People with hemophilia usually need a replacement of clotting factor, which is a small part of whole blood. People with sickle-cell disease may require frequent blood transfusions. Early blood transfusions consisted of whole blood , but modern medical practice commonly uses only components of the blood, such as fresh frozen plasma or cryoprecipitate.
Blood substitutes also called 'artificial blood' or 'blood surrogates' are artificial substances aiming to provide an alternative to blood-based products acquired from donors. The main blood substitutes used today are volume expanders such as crystalloids and colloids mentioned above. Also, 'oxygen-carrying substitutes' are emerging. Buffer solutions are used to correct acidosis or alkalosis. Lactated Ringer's solution also has some buffering effect.
A solution more specifically used for buffering purpose is intravenous sodium bicarbonate. Parenteral nutrition is feeding a person intravenously, bypassing the usual process of eating and digestion. The person receives nutritional formulas containing salts , glucose , amino acids , lipids and added vitamins.
In a second study, 15 high-dose vancomycin therapy by continuous infusion led to fewer adverse drug reactions and treatment failures relative to standard-dose and high-dose therapy by intermittent infusion, although the results were not explicitly reported.
Three studies with level II-3 evidence i. All three studies were retrospective. One involved a pediatric population 16 and 2 involved adult patients. The duration of intermittent therapy was not described, and these 2 patients were eventually switched to continuous infusion. Six of the children received vancomycin by continuous infusion from the beginning of therapy and underwent serial determinations of vancomycin in the serum and CSF during the initial 48 h of treatment.
For these children, vancomycin concentration was detectable in the CSF at 48 h. The drug concentration remained stable between day 3 and cessation of therapy range 1 to 3. Vancomycin became undetectable in the CSF within 24 h of discontinuation. No complications were associated with continuous infusion of vancomycin, although renal function and adverse events were not reported. All 13 patients survived and were considered cured. One child experienced a recurrence 1 month after discontinuation of therapy.
Two patients in each group had additional mixed infections Klebsiella pneumoniae and Pseudomonas in both and received concomitant therapy with monobactams or aminoglycosides.
Mean baseline SOFA scores were 6. The mean SOFA score at the end of therapy was significantly lower than baseline in the group that underwent continuous infusion 4. Mean serum concentrations of vancomycin were compared between continuous and intermittent dosing, but the statistical significance was not reported at 2 h, No adverse effects were observed in either group. Interestingly, patients assigned to undergo continuous dosing were given an initial dose of mg IV over 10 min. Such rapid administration of vancomycin may increase the risk of infusion-related adverse effects.
Twenty-two of the 23 patients who received vancomycin by both modes of administration had higher serum concentrations of the drug with continuous infusion; the one outlier actually received a lower daily dose during the continuous infusion course than the intermittent dosing course.
All patients achieved serum concentrations above the MIC with continuous infusion, whereas 4 patients had concentrations below the MIC with intermittent dosing. Three patients experienced adverse drug reactions while receiving vancomycin by continuous infusion a rash in 2 patients, interstitial nephritis in 1 patient ; no adverse reactions were observed during intermittent infusion.
A pediatric study reported continuous and intermittent administration of vancomycin to children with staphylococcal meningitis and ventricular shunt infections. In a study of critically ill adults, 17 there was significant improvement in SOFA scores and reduction in WBC counts with continuous infusion of vancomycin, but no significant changes were observed in the intermittent dosing group.
However, patients in the continuous dosing group had higher SOFA scores and WBC counts at baseline, which signifies a potentially sicker population than the control group. No adverse effects were reported in either group. In a third study, 18 adult patients treated with vancomycin by continuous infusion achieved higher serum concentrations and consistently maintained concentrations above the MIC.
However, the dosing and sampling strategies were highly variable. Limited evidence is currently available to evaluate the clinical efficacy and safety of vancomycin by continuous infusion relative to conventional intermittent infusion.
Published trials were highly heterogeneous in terms of study design, dosing regimens, and serum monitoring strategies, and evaluated a vast array of outcomes that rendered comparison across trials difficult. Although both adult and pediatric populations were of interest, only one pediatric study met the inclusion criteria for this review. A common limitation to the existing literature is the relatively small sample populations used for individual studies.
Sample size was generally less than 30, and the largest trial involved only patients. Unfortunately, that study also used different prespecified target concentrations of vancomycin for the intermittent and continuous infusion groups.
Therefore, the results reflected not only the 2 modes of vancomycin administration but also a discrepancy in target serum concentrations. The other 8 studies that were identified and analyzed here did not report a priori sample size calculations.
It was also unclear whether they were designed to be superiority, non-inferiority, or equivalence studies. Some studies assessed only pharmacokinetic and pharmacodynamic outcomes. Other studies included in this review focused on whether continuous vancomycin dosing would improve clinical efficacy and safety rather than on surrogate pharmacokinetic outcomes.
As noted earlier, one of these studies was significantly underpowered to assess treatment failure, 8 and the other did not report the required sample size a priori, 14 so it remains unclear whether it had adequate power to assess cure rate. A study of chronic osteomyelitis was designed primarily to evaluate standard-dose versus high-dose vancomycin, with the high-dose group further divided into continuous and intermittent dosing. The other retrospective study revealed a link between continuous infusion and higher frequency of serum concentrations above the MIC.
Only the lowest recorded serum concentrations of vancomycin were reported, so these data did not capture whether target concentrations were sustained throughout the course of treatment or whether supratherapeutic concentrations were observed.
It would be useful to assess the satisfaction of nurses and patients, potential administration challenges e. It might be argued that continuous infusion is more labour-intensive, but this end point is highly subjective.
It is also important to note that cost estimates should be interpreted with caution as they are subject to variation according to dosage adjustments and serum monitoring protocols of the institution. Overall, the studies included in this review had inconsistent findings.
They were highly heterogeneous in terms of methodologic design, patient population, dosing and sampling strategies, and outcomes evaluated. Common limitations to these studies were small sample size, poor reporting of adverse drug reactions, and insufficient consideration of potential confounding factors that might bias outcomes.
For example, timely and accurate diagnosis and initiation of antibiotics have been shown to improve mortality in the intensive care unit.
In light of these limitations, there appears to be a lack of sound evidence to support the use of continuous infusion of vancomycin for treating multidrug-resistant gram-positive infections.
Furthermore, continuous infusion does not appear to reduce costs relative to traditional intermittent dosing. This systematic review had some limitations. Only articles published in English and French were included. As a result, 3 potentially relevant articles 2 in Spanish and 1 in Japanese were excluded. Only studies that directly compared continuous with intermittent vancomycin infusion were eligible for review.
Studies evaluating pharmacokinetic characteristics and clinical efficacy of continuous infusion alone were not included. Current evidence does not support routine administration of vancomycin by continuous infusion for various multidrug-resistant gram-positive infections. Although this review does not negate the potential role of continuous vancomycin infusion in unique therapeutic circumstances, such specific cases warrant individualized clinical judgement based on patient-specific parameters and evaluation of the potential benefits and risks of each administration modality.
National Center for Biotechnology Information , U. A recent study by Benko et al. In both treatment groups serum concentrations exceeded the MIC by four to five times. The serum bactericidal titres were equal in both regimens.
The latter study and other clinical trials with ceftazidime, demonstrated the effectiveness of CI and confirmed our results. The stability of an antibiotic is an important consideration if CI administration is to be used.
Thus, in this study, the antibiotic solution was changed every 8 h for the CI group. No problems with stability occurred during the study period. This characteristic reduces the applicability of meropenem for CI for outpatient parenteral antibiotic therapy. In conclusion, the rationale for using meropenem as CI is supported by the pharmacokinetic data of our study.
Serum concentrations remained above the MIC for most likely target pathogens in all patients. A loading dose of 2 g of meropenem should be given initially to attain bactericidal drug concentrations as rapidly as possible. During continuous infusion, no major adverse events related to the use of CI were observed. Thus, meropenem can be administered safely by CI. This study did not evaluate the clinical efficacy of the two different antibiotic treatment schedules.
Further investigations are required to evaluate pharmacodynamic and economic perspectives in the clinical setting. In-vitro activity of meropenem for clinically important Gram-positive and Gram-negative pathogens Mean serum meropenem concentrations with sd bars. Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide.
Sign In or Create an Account. Close mobile search navigation Article navigation. Continuous infusion versus intermittent administration of meropenem in critically ill patients Florian Thalhammer.
Abstract This prospective crossover study compared the pharmacokinetics of meropenem by continuous infusion and by intermittent administration in critically ill patients. View large Download slide. Email alerts New issue alert.
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Besides these uses, many medications are administered by intravenous infusion. A piggyback intravenous infusion is the intermittent delivery of an additional fluid or medication through the primary intravenous line from a second source of fluid with a secondary set of intravenous tubing. Piggyback intravenous infusion set.
ADMINISTERING INTERMITTENT INTRAVENOUS MEDICATION USING A SECONDARY SET Definition: An intermittent infusion is a method of administering a medication mixed in a small amount of IV solution, such as 50 ml or ml.
Administering Intermittent Intravenous Medication (Secondary Medication) and Continuous IV Infusions Intravenous intermittent infusion is an infusion of a volume of fluid/medication over a set period of time at prescribed intervals and then stopped until the next dose is required. An infusion set for an intermittent or continuous administration of a therapeutical substance, such as insulin, comprises a cannula housing (1) with a soft plastic cannula (2) to be placed inside the body of a patient, where the cannula together with the cannula housing (1) form a through passageway the inlet of which into the cannula housing (1) is covered by a membrane.
Intravenous therapy (IV) is a therapy that delivers liquid substances directly into a vein (intra-+ ven-+ -ous). The intravenous route of administration can be used for injections (with a syringe at higher pressures) or infusions (typically using only the pressure supplied by gravity). secondary infusion Definition the administration of a parenteral drug that has been diluted in a small volume of iv solution(50 to ml) over 30 to 60 minutes.