Features of short-term and long-term infusion therapy: review of the vascular access technologies from the point of view of the nurse. Catheterization of peripheral veins

Background. Infusion therapy (IT) has a number of features that both doctors and nurses need to know. IT can be performed via a needle, a peripheral intravenous catheter (PIC), and an implanted system for long-term infusions (ISLI). Objective. To describe the features of short-term and long-term IT. Materials and methods. Analysis of literature sources on this topic. Results and discussion. First of all, every healthcare worker should remember that the patient should be identified before any manipulation and then the procedure may start. IT via the needle has a number of disadvantages: complications due to the frequent punctures and prolonged stay of needle in the vein; limited possibility of long-term IT; increased risk of needle injuries among medical staff. The advantages of PIC above needle include the lower risk of infection, better safety, the possibility of rapid administration of drugs in various combinations, easy use of IT and parenteral nutrition, and the ability to monitor central venous pressure. PIC are classified by the presence of an additional injection port, by the material from which they are made, by the shape of the needle tip sharpening, by the visibility on X-ray and size. Venoport Plus (“Yuria-Pharm”) is an elastic teflon catheter with a low coefficient of surface friction, X-ray contrast strips and the possibility of a long stay in a vein (up to 72 hours). The advantages of the Venoport Plus PIC are the adaptive shape of the cap, the optimal inclination angle and SMART SLOT – a hole near the tip of the needle, which allows you to visualize the blood between the catheter and the needle without waiting for it to appear in the indicator chamber. The most suitable for the PIC placement veins are located on the outside of the hand and on the inner surface of the forearm. It is recommended to use the ulnar vein only for laboratory blood sampling and emergency medical care. When choosing PIC one should take into account the vein diameter, necessary speed of infusion, potential time of stay of a catheter in a vein, and features of the infused solution. After installing PIC, it is advisable to use special transparent aseptic bandages. Bandage replacement is performed as needed; daily replacement is not required. After PIC installation and after infusion, PIC should be washed with 0.9 % NaCl, heparin (1:100 dilution), or Soda-Bufer solution (“Yuria-Pharm”). If the catheter is not used, washing should be performed once a day. ISLI Yu-Port (“Yuria-Pharm”) provides long-term venous access and can be used if the patient needs multiple administrations of drugs during a long course of therapy. Conclusions. 1. IT can be conducted via a needle, PIC, or ISLI. 2. The advantages of PIC over the needle injection are lower risk of infection, better safety, the possibility of rapid administration of drugs in various combinations, facilitated use of IT and parenteral nutrition, and the ability to monitor central venous pressure. 3. PIC Venoport Plus (“Yuria-Pharm”) is an elastic teflon catheter with an adaptive shape of the cap and the optimal angle. 4. When choosing PIC one should take into account the vein diameter, the required speed of infusion, the potential time of stay of a catheter in a vein, and the features of the infused solution. 5. ISLI Yu-Port provides long-term venous access and can be used if necessary for the multiple administrations of drugs during a long course of therapy.

A Nonsurgical Embryo Transfer Technique for Fresh and Cultured Blastocysts in Rats

The use of a nonsurgical embryo transfer technique in rodents eliminates the potential pain, distress, and health complications that may result from a surgical procedure and as such, represents a refinement in rodent assisted reproductive techniques. A nonsurgical technique has not been previously developed for use with rat embryos. Here we describe an efficient method to deliver either fresh or cultured blastocyst stage embryos to the uterine horn of pseudopregnant female rats using a rat nonsurgical embryo transfer (rNSET) device. The rNSET device is composed of a Teflon catheter and a hub that attaches to a 2 μL pipette. Oxytocin is used to dilate the cervix before the delivery of blastocysts, allowing passage of the rNSET catheter directly into the uterine horn for embryo delivery. The efficiency of recovery of pups after nonsurgical embryo transfer is similar to the efficiency after surgical embryo transfer. Furthermore, the technique is not stressful to the subjects, as demonstrated by the absence of a decrease in weight or increase in fecal corticosterone level in recipients of embryos delivered nonsurgically, without the use of anesthesia or analgesia.

Attenuation of postexertional hypotension by cardiac afferent blockade

Naloxone eliminates postexertional hypotension (PEH) in human and animal models. The effect of naloxone on sympathetic activity during hemorrhage and generation of arterial baroreflex function curves can be stimulated by blockade of cardiac afferent receptors. We tested the hypothesis that cardiac afferent blockade would eliminate PEH in eight spontaneously hypertensive rats (SHR). Rats were instrumented with a Silastic-tipped catheter inserted into the pericardial space. Four weeks later, a Teflon catheter was placed in the descending aorta via the left common carotid artery for measurement of mean arterial pressure (MAP) and heart rate (HR). MAP and HR were examined before (preexercise) and after (postexercise) a single bout of dynamic treadmill exercise (9-12.0 m/min, 10-18% grade for 30-40 min) under three experimental conditions: control, cardiac efferent blockade, and combined cardiac efferent and afferent blockade. MAP significantly decreased (29 +/- 5 and 25.6 +/- 4 mmHg) in the control and cardiac efferent blockade conditions after exercise. However, when cardiac afferents were blocked, the hypotensive response to mild dynamic exercise was significantly attenuated (-6 +/- 3 mmHg). Thus blockade of cardiac afferents eliminated PEH in the SHR. These data suggest that inhibitory influence of cardiac afferents on the circulation may be enhanced after exercise.

Cannulation of the lateral saphenous vein-a rapid method to gain access to the venous circulation in anaesthetized guineapigs

Previously published methods of venous puncture in guineapigs did not provide reliable venous access for more than a few minutes, and therefore surgical intervention was necessary to cannulate the femoral or external jugular vein or the vena cava. In the present report cannulation of the Vena saphena lateralis via the Vena plantaris lateralis or of the Vena saphena medialis is described by inserting a 22 gauge teflon catheter. These catheters are commercial products. The method is timesaving and inexpensive. Successful cannulation was accomplished in 34 of 35 guineapigs. No lethal incidents occurred.

Reduced vascular responsiveness after a single bout of dynamic exercise in the conscious rabbit

We measured agonist-induced changes in the iliac artery blood flow velocity (IFV) independent of baroreflex-mediated compensatory mechanisms in chronically instrumented New Zealand White rabbits (n = 8). Animals were instrumented with a Doppler flow probe around the right common iliac artery. A Teflon catheter was inserted into the right iliolumbar artery for local infusion of the vasoactive agonists. Another Teflon catheter was inserted in the left femoral artery for the measurement of pulsatile and mean arterial (MAP) blood pressures and heart rate (HR). The alpha-adrenergic receptor agonist phenylephrine (PE, 1.32–10.0 micrograms), the beta 1- and beta 2-adrenergic receptor agonist isoproterenol (IP, 0.022–0.11 micrograms), and the purinergic receptor agonist adenosine (AD, 10.0–100.0 micrograms) were injected into the functionally isolated hindlimb, and dose-response curves were generated. Changes in IFV were obtained without changes in MAP or HR. Exercise increased HR, MAP, and IFV (65.3 +/- 7.1 beats/min, 11.1 +/- 2.2 mmHg, and 2.2 +/- 0.3 kHz, respectively). The maximum responses to PE, AD, and IP were reduced 29.0 +/- 6.7, 50.7 +/- 8.5, and 61.0 +/- 8.1%, respectively, after exercise. In conclusion, exercise attenuated adrenergic and purinergic receptor-mediated vascular responses in the intact conscious rabbit.

Nasobiliary Drainage

Placement of nasobiliary tubes has now become a widely accepted method for therapeutic drainage and instillation of solvents into the biliary tree. The author routinely uses a 300 cm long, 7 or 10 French, specially performed Teflon catheter, which adapts to the anatomy of the duodenum and bile ducts, for the following indications: decompression of obstructed bile duct in acute suppurative cholangitis; prevention of stone impaction after endoscopic sphincterotomy; sequential cholangiography; biliary fistula; instillation of solvents for common bile duct scones; local radiotherapy of biliary malignancies; aspiration of bile for chemical and bacteriological studies; and drainage of pancreatic pseudocysts. Pancreatic or biliary drains should supplement traditional diagnostic and therapeutic modalities in patients with surgical or medical lesions of the pancreas and biliary tree.