Central Venous Catheter Technique in Small Children - Research Paper Example

CENTRAL VENOUS CATHETER TECHNIQUE IN SMALL CHILDREN INTRODCTION: A central venous catheter is passed to gain venous access to the thoracic part of vena cava or the up to the right atrium as defined by Ms Alison (Alison 2005). Passing a central venous catheter is a difficult technique especially in small children where it carries a high rate of mortality and morbidity. BACKGROUND: Ultrasound guided central venous catheterization is safer and more proficient in pediatric population, especially in children weighing less than 5 kilograms. Several papers have described the feasibility of the ultrasound guided technique approaching one vein at a time. In our retrospective cohort paper we theorize a systematic approach aimed at identifying the most suitable vein performing a pre procedural scan of all the possible site for vein cannulation and thereafter choosing the most appropriate in term of size and other factors such as collapsibility during respiratory cycle or anatomical anomalies. This systematic approach allowed identifying the brachiocephalic vein as the more suitable for central line placement, and along with in plane approach we were able to be successful in 100% of cases without complication. TYPES OF CENTRAL VENOUS CATHETERS: There are different types of central venous catheters as described by Ms Alison (Alison 2005). These are categorized depending upon: 1. The site of insertion, 2. Intended life span, 3. The pathway acquired or 4. The length of the catheter. The sites of insertion include: 1. Subclavian, 2. Umbilical, 3. Internal jugular, 4. Femoral, 5. Brachial, 6. Sephanous, 7. Cephalic or 8. Basilic veins. The intended life span means: 1. Permanent / long-term, 2. Temporary / short-term. The pathway acquired includes: 1. Tunnelled and 2. Non-tunnelled. The length of the catheter means: 1. Short or 2. Long catheter. INDICATIONS FOR CENTRAL VENOUS CATHETERIZATION: As published by The Great Ormond Street Hospital for Children’s publications in 2007, the central venous catheter is usually inserted into a neck vein to gain access to the right atrium. It is required to gain an ease of access for taking regular blood samples, for administration of medicines in patients undergoing chemotherapy or for giving total parenteral nutrition. It may also be required for administration of anesthetics, peri operative management or long term management of chronic illness. It is also indicated for measurement of central venous pressure. CONTRAINDICATIONS FOR CENTRAL VENOUS CATHETERIZATION: Alan (Alan S. 2008) describes the contraindications for placement of central venous catheterization as: 1. Infection over the target area, 2. Thrombosis of the target vein, 3. Injury over the target area. FACTORS EFFECTING CENTRAL VENOUS CATHERIZATION: The success of this procedure depends upon a number of factors including the general condition of the child as described by Grebenik (Grebenik 2004). These include an experienced hand performing the procedure, the site of insertion of cannula, the presence of vascular anomaly, clotting problems or any previous cannulation procedure performed in the past. Because of these all factors, an ultrasound guided technique of central venous catheterization is rapidly becoming a preferable procedure for a central line placement in infants, neonates and children. Ultrasound guided technique has an advantage over the blind procedure for gaining the safest venous access and ensuring a flawless approach. RISK FACTORS ASSOCIATED WITH THE TECHNIQUE: There are certain risk factors associated with this procedure like the risk of infection or thrombosis, which may lead to various complications as described by Haas (Haas 2003). Therefore, a standard level of antiseptic measures is always expected to be attained prior to procedure in order to achieve successful results and avoid the chances of infection. As described in the report by The Great Ormond Street Hospital for Children, a collar or cuff is usually required to keep the catheter in place in cases requiring a long term placement of the catheter; while no collar is needed in short term needs like after a surgery or in an intensive care unit. THE SITES OF INSERTION IN NEONATES AND INFANTS: 1. BRACHIOCEPHALIC VEIN: The most preferred choice for insertion of a central venous catheter in neonates and infants is that of the brachio-cephalic vein although internal jugular and sub clavian veins have also been the veins of choice. This is the largest and most easily assessable vein in infants and small children. There are certain advantages and disadvantages regarding this procedure. The greatest advantage of this vessel is that it is far away from the intra thoracic structures thereby reducing the risk of hemothorax and pneumothorax. A big disadvantage is that the catheter may not pass centrally; instead it may take entrance into the axilla, or above into the internal or external jugular vein. Charles has described different techniques and devices used in various methods of catheter placement (Charles 2009). These techniques are usually age specific. A special technique known as Seldinger technique is a favorable method in order to avoid certain complications young children. In certain difficult cases, there may be a need for a bright trans-illumination light source in order to enhance the visibility. The procedure is usually carried out under general anesthesia. Initially, for induction of anesthesia, a butterfly needle can be used. This is followed by an appropriate catheter after anesthesia. It is recommended to make use of a T-connector in order to minimize the amount of drugs required to flush the drugs administered through the intravenous line. This is particularly true for infants. A burette is required for titration of fluids administered and in order to limit the total infusion. In infants and newborns, a flow limiting infusion pump is used. In addition, the flow rates are also dependent upon the: 1. Brand of the catheter, 2. Type of tubing and 3. Extensions and stop cocks. In case of the catheterization of brachiocephalic vein, it has an advantage over other veins from being away from the intrathoracic structures, thereby reducing the risk of pneumothorax or hemothorax. The main disadvantage of inserting a central venous line in brachiocephalic vein is that many catheters passed at this site do not gain access to central veins, instead they become ‘captured’ in the axilla or otherwise, may pass into the internal or external jugular vein. Still other disadvantages include a risk of infection as there are more chances of the catheter migration with movements of the arm. Inserting a venous catheter in brachiocephalic vein is a preferred method of insertion mostly acquired by the radiologists and pediatric staff for insertion of the peripherally inserted central catheters (PICC) which are of significant use for long term cases extending from seven days to three months. These catheters help to improve the quality of patient care provided on account of a minimal need of gaining peripheral access and a decreased need for venipunctures for blood sampling. There is not much data available to support the routine use of heparin in order to prevent the thrombosis and occlusion of the catheter. The patient’s arm is first prepared and drapped according to the aseptic measures. The modified Seldinger technique is used for cannulating the brachiocephalic vein which makes use of the special long catheters and wires or by intracath approach which involves the passage of a catheter through a needle. Once the vein is entered, if the catheter cannot be threaded, the advancement may be achieved by: 1. Initiating rapid administration of intravenous fluid, 2. Positioning the arm in cephalic direction or 3. An anterior displacement of the shoulder. If per cutaneous techniques may not be approached, direct venous cut down may be an alternate option. 2. THE SUBCLAVIAN VEIN: According to Charles there are certain advantages and disadvantages for insertion of central venous catheter in subclavian vein. These include: 1. Fixed landmarks, 2. An easy approach for long term or chronic cases, 3. Patient comfort. The disadvantages include: 1. Pneumothorax or 2. Hemothorax. For insertion of a central venous catheter in a subclavian vein, the needle is inserted immediately below the clavicle at a point about one and a half to two third of its length from the sternoclavicular junction. With its very close approximation with the clavicle, the needle is directed in direction of the suprasternal notch. The whole process is performed accompanied by a continuous aspiration. As soon as the blood is aspirated in the catheter, it is preceded further. If this technique is not used, then it is recommended to locate the Subclavian vein with a small gauge-needle. Once the insertion is achieved, an antibiotic cream is applied at the insertion site, the catheter is stitched in its place in order to fix it, followed by an appropriate dressing. If the procedure is being carried out under controlled ventilation, the risk of hemothorax or pneumothorax can be decreased by ceasing the ventilation for a moment while going for the subclavian vein. This keeps the apex of the lung away from the catheter tip, thus preventing its damage. Once the venipuncture has been achieved, a positive end expiratory pressure is maintained thereby reducing the risk of air embolism. The venous placement of wire is confirmed before final dilation or fixation is performed in order to be sure about the correct placement. THE SELDINGER TECHNIQUE OF CATHETERIZATION: The Saldinger technique of catheterization is helpful for insertion of central venous catheters in those infants who are difficult to cannulate. It is also called as ‘micropuncture’. Jannet describes the details of this procedure (Jannet 2007). In this technique, a small gauge, peripheral intravenous catheter is inserted under aseptic measures. The needle is then removed followed by the insertion of a short guidewire a few centimeters beyond the peripheral intravenous catheter tip which is still in the peripheral circulation. It is then removed over the wire. After anesthetizing the skin, the introducer for peripherally inserted central catheter (PICC) is then inserted over the guidewire. The guide wire is then removed after the catheter is in its correct place. CASE STUDY: Given below is an account of the study performed to show the benefits of ultrasound guided insertion of the central venous catheter in brachio-cephalic vein in neonates. As the technique particularly requires a skillful hand regarding the neonates, infants and children, the ultrasounded guided venous access has been beoming the standard technique preferred for this procedure. This greatly increases the chances of success of this procedure This study was performed using the brachio-cephalic venous as the preferred choice as this is the largest and easiest accessable vein in neonates and small children. Although previously, much of the successful studies have been performed using the subclavian and internal jugular vein. The study was performed by PLEASE ENTER THE INFORMATION ABOUT THE SOURCE OF THIS STUDY/POWER POINT PRESENTATION. The study was based on a review of all the CVC insertions involving less than six years old children in the Pediatric Intensive Care Unit and Pediatric Oncology Department. The analysis did not include the PICC’s. The central veins were carefully evaluated under ultrasound guidance in order to chose the vein to puncture. This is called as the ‘Rapid Central Vein Assessment (RaCeVa) using the linear probe 10-14 Mhz ‘hockey stick’ for ultrasound. Different types of catheters were taken into consideration including silicon, polyurethane, power injectable polyurethane, single lumen and double lumen catheters. The final selection was made in favour of the catheter measuring 3 Fr to 5 Fr in diameter using following equation: Vein mm = or > catheter Fr The special kits available for micro-introduction were used for all patients. These kits contain: 1. 21 G echogenic needles, 2. Soft straight tip 0.018 “ guide-wire and 3. 3.5 or 4.5 Fr micro-introducer. All CVC’s were inserted using the ‘in-plane’ approach under real time ultrasound guidance. The use of ultrasound for continued for assessment of the guide-wire direction, soon after its insertion in the needle. In addition, the help of intracavitary ECG method was also taken wherever required during the procedure. In most of the studied cases, the catheter was tunneled to the infraclavicular area in order to achieve a more favourible exit site. Finally, at the end of the procedure, the ultrasound of intercostal spaces was performed to exclude the possible presence of pneumothorax or any other pleuro-pulmonary damage. The sutureless devices were used in all cases to finally fix the catheters in their place. Cyano acrylate glue was used to seal the puncture and the exit sites and transparent dressing applied. An additional confirmation for correct placement of catheter was performed in all cases either by a chest radiograph or echocardiography. The results of this review were as under: 183 ultrasound guided CVC insertions were made in 165 patients out of which: 15 patients were < 1 month old, 70 patients were between 1-12 months old and 80 patients were 1-6 years old. In all these patients, supra-clavicular approaches were used including: 167 cases for brachio-cephalic vein puncture, 10 involving the internal jugular vein, 3 for subclavian vein and 2 for the external jugular vein. All of the above cases underwent successful CVC insertions without any puncture-related complications like hemothorax or pneumothorax. In about 85% of cases, the vein was punctured at first prick. Regarding the 167 insertions of brachio-cephalic vein: 123 cases were performed using the landmark measures + IC-EKG + post operative TTE or X-ray, with no malpositions reported. 44 cases were performed using the landmark measures + post operative TTE or X-ray, with only 4 cases reported having tip ‘too-deep’ at post-op control. Thus it was concluded by the results of this study that assessing a patient carefully before inserting a CVC line allows a more appropriate choice of the vein to be pricked, especially in terms of its caliber, depth and the complications pleural or arterial damage. The results of this study also show the greater success rates for brachio-cephalic vein catheterization espeically in patients less than six years old because of its largest caliber and a relatively easy approach. COMPLICATIONS OF CENTRAL VENOUS CATHETERIZATION: Some of the various complications as published by Samuel in his book (Samuel 2010) include: 1. Infection, 2. Sepsis, 3. Thrombosis, 4. Distal ischemia due to thrombosis and 5. Catheter malfunctioning. These complications are preventable if strict aseptic measures are carried out during the process of insertion. GUIDELINES APPROVED BY AMERICAN SOCIETY OF ANESTHESIOLOGISTS: According to a report published by the American Society of Anesthesiologists, (Jannet 2007) certain guidelines were established for placement of a central venous catheter in any patient. According to these guidelines, the resource preparation for this technique includes: 1. Availability of an aseptic physical environment where the catheterization is planned to be placed, 2. Availability of the standardized equipment set, 3. Availability of a professional assistant and 4. Using a checklist for placement and maintenance of the catheter. Ms Alison (Alison 2009) has described some protocols required to prevent the chances of infection after central venous catheterization. These are given below: Key Points Grade of evidence Use of maximal sterile barriers during the insertion of central venous catheters reduces colonization of the catheter A Staff knowledge about the importance of maximal sterile barriers and aseptic technique can decrease the incidence of blood stream infection. B Wearing gloves reduces hand contamination C The combined use of alcohol and gloves reduces the incidence of late-onset infection D CONCLUSION: The central venous catheterization is an important procedure requiring a skillful handling and technique especially in case of infants and small children. Its main indications remain for the use of certain medications in patients of chronic illness, for administration of carefully calculated anesthetic drugs and for measurement of central venous pressure. The preferred choice of vein in infants is the brachiocephalic vein as it is the largest accessible vein in infants. Different studies have now shown a higher success rate of the ultrasound guided technique of central venous catheterization as it limits the chances of wrong insertion. This also ensures the correct placement of catheter before final fixation is performed. The correct placement of catheters can also be confirmed by the chest radiographs performed after the procedure. The Seldinger technique of catheterization is a specialized technique used in difficult cases of insertion. It requires the use of a short PIV catheter followed by a guide wire and then finally, the insertion of the PICC once the PIV is removed. The process of insertion of central venous catheter can lead to certain complications like infection and thrombosis leading to peripheral ischemia but one can minimize the chances of infection by performing the procedure under strict aseptic measures. WORKS CITED Alan S. et. al (2008) Central Venous Catheterization [Online] The New England Journal of Medicine. Available from: http://www.ttuhsc.edu/som/internalmedicine/pulm/education/procedures/cvcplacement.pdf Charles J. et. al. (2009) A Practice of Anesthesia for Infants and Children [Online] Google Books. Available from: http://books.google.com.pk/books?id=iOqXLFBQt_UC&pg=PA1056&lpg=PA1056&dq=technique+of+brachiocephalic+vein+catheterization+in+infants&source=bl&ots=OQSxWcZ1gW&sig=NOhIbPGGxXxkDFwXjvrNacMMPRE&hl=en&sa=X&ei=t7tbUcaTJofkrAfohIGIBA&ved=0CD4Q6AEwAw#v=onepage&q=technique%20of%20brachiocephalic%20vein%20catheterization%20in%20infants&f=false C. R. Grebenik et. al (2004) British Journal of Anesthesia [Online] 92 (6): 827-30. Available from: http://bja.oxfordjournals.org/content/92/6/827.full.pdf Great Ormond Street Hospital for Children (2007) The Child First and Always [Online]. Available from: http://www.gosh.nhs.uk/medical-conditions/procedures-and-treatments/insertion-of-a-central-venous-catheter/ Haas et. al. (2003) Current Opinion in Anesthesiology [Online] Volume 16 Issue-3-pp291-303. Available from: http://journals.lww.com/co-anesthesiology/Abstract/2003/06000/Central_venous_catheter_techniques_in_infants_and.9.aspx Janet Pettit et. al (2007) Peripherally Inserted Central Catheters; Guideline for Practice [Online]. Available from: http://www.nann.org/pdf/PICCGuidelines.pdf Ms Alison Young et. al (2009) A Review of the Literature of Central Venous Catheters [Online] NHS Education for Scotland. Available from: http://www.knowledge.scot.nhs.uk/media/CLT/ResourceUploads/1011695/CVC%20Managment%20in%20Neonates.pdf Samuel Eric Wilson (2010) Vascular Access Principles and Practice [Online] Google Books. Available from: http://books.google.co.uk/books?id=ogyoOFHXWaMC&printsec=frontcover#v=onepage&q&f=false Read More