 |
|
Brief Reports Indian Pediatrics 2001; 38: 889-892 |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Use of Percutaneous Silastic Central Venous Catheters in the Management of Newborn Infants |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Central venous catheters (CVC) are essential in the management of sick newborns. Peripheral CVC are placed based on an anticipated need of prolonged intravenous fluid therapy or total parenteral nutrition. Various complications including thrombosis, embolism, extravasation and infection have been reported with the use of CVC’s in adults and children. We report our experience with 44 peripheral CVC’s used in 38 infants over a 10 month period. Methods Thirty eight infants admitted to the Neo-natal Intensive Care Unit at Nepean Hospital between October 1995 and September 1996 required peripheral CVC for prolonged fluid therapy and parenteral nutrition. All these babies were analyzed in this study. Per-Q-cath (23 gauge) silastic central venous catheters were used for catheterization. The catheters were inserted according to the "Through the Needle" technique under strict asepsis(1). Catheters were checked so that the tip was placed either in the SVC for the scalp and arm insertions or the IVC for leg insertions. The CVC was used exclusively for intra-venous fluid therapy or parenteral nutrition. Total parenteral nutrition (TPN) was prepared in the pharmacy under sterile conditions. Fluids/TPN were changed daily with strict aseptic technique. Medications and blood transfusions were administered via a separate peripheral vein. Three types of complications were analyzed: mechanical, septic and thrombotic. Mechanical complications included intra-thoracic effusions, catheter dislodgment, leaking, or perforation. Septic complications included bacteremia and local infection. For the diagnosis of catheter related sepsis, blood cultures were collected through the CVC and the catheter tip was sent for culture.Antibiotics were not administered through the CVC. Catheters were removed electively as soon as the infants reached full feeds. The CVC was also removed if there was any evidence of a complication including effusion, occlusion, extravasation or bacteremia. Statistical analy-sis was done by Chi square test. Results During the 10-month period, a total of 44 peripheral CVC were inserted in 38 newborn infants. Thirty five of these infants were preterm and 6 babies required repeat catheterization. Birth weights ranged from 465 to 4010 grams with an average of 1380 ± 757 (SD).The gestational ages ranged from 23 to 41 with an average of 29.7 ± 4.3 (SD) weeks. Thirty two (73%) catheters were inserted in very low birth weight (VLBW) infants of which 23 (51 %) were placed in babies <1000 grams.
CVC: central venous catheter
Rate = complications x 1000 p value <0.001 Nineteen (43%) CVC were inserted through the scalp veins of which 4 (21%) could not be advanced beyond the neck veins (Table I). Eighteen (41%) catheters were placed through the arm veins and were successfully placed with the catheter tips placed high in the SVC. Seven catheters were inserted through the leg veins and 2 (29%) of these had to be left with the tips of the catheter in the thigh veins. Thirty-eight (86%) of the catheters were placed successfully in either the SVC or the IVC. Thirty (68%) of the catheters were removed electively after the babies had reached full enteral feeding. Complications were encountered with 14 catheters (32%). Bacteremia was seen in 3 patients. Two of these had Staphylococcus-Epidermidis sepsis and one had Candida sepsis. The catheter tip in the patient with candida sepsis on culture grew the same species of candida. All 3 catheters were removed after the sepsis had been confirmed. Local phlebitis was seen in 3 patients, all infants in whom the tip of the catheter could not be advanced satis-factorily to the proper location. Five catheters (11%) were removed due to high pressures in the infusion pumps. Local thrombosis at the catheter tip or deposition of calcium phosphate crystals could have been responsible for the catheter occlusion. One patient developed pericardial tampo-nade after 3 days of catheterization and died of this complication. A chest X-ray done later confirmed that the catheter had migrated and lay in the right atrium at the time of death. Extravasation was seen with 2 catheters. A total of 14 complications were seen with 44 catheters in situ for a total of 650 days, which represents a rate of 1 complication/46.4 catheter days. Data analysis with regard to site of insertion showed that catheters inserted through the arm veins were associated with a significantly less risk as compared to catheters sited through the scalp or the leg veins (complication rates of 13 vs 23 and 44 per 1000 catheter days, respectively; p <0.001) (Table 1). Fifteen (83%) catheters inserted through the arm veins were removed after reaching full feeds as compared to 12 (63%) scalp and 3 (43%) leg catheters. Infections, both local and systemic were encountered more frequently with the leg catheters. Swelling over the shoulder region (extravasation) was seen with 2 catheters inserted through the scalp veins. These were not associated with any pleural effusions. Complications were seen more frequently with catheters placed in babies weighing less than 1500 grams. Twelve catheters were placed in infants weighing >1500 grams and 2 (17%) of these developed complications. Twelve (38%) complications were encoun-tered with 32 CVC inserted in VLBW infants. Babies in the higher weight group were graded to full feeds earlier and catheters were removed at 11 days as compared to 16 days in the VLBW group. Discussion Central venous catheters form an integral part of management in most neonatal intensive care units(2). Surgically placed central venous lines have been largely replaced by the use of the more pliable, peripherally sited silastic central venous catheters. In our group of patients we have demonstrated the feasibility and safety of using central venous catheters for providing parenteral nutrition for prolonged periods of time in extremely low birth weight (ELBW) infants. Forty-four catheters were in situ for a cumulative 650 days with an average duration of 15 days per catheter. However, the use of these catheters may be associated with complications. Infectious complications have been reported in a range of 12-32% in various reports(3,4). In our series, 6 catheters (14%) were associated with infection. Three of these were associated with systemic sepsis and three developed local phlebitis. However, the risk of infection is known to increase with the duration of catheterization and a better index of infective complications would be number of episodes per 1000 days of catheter use. Three episodes of systemic sepsis were identified with 650 days of catheter use with an index of 4.6 infections /1000 days which is comparable to 3.7 and 5.7 reported by other authors(4,5). Mechanical complications in reports have ranged from 15% to 26%(4,5). In our series, mechanical complications were noted with 3 (7%) catheters. Two of these developed extra-vasation and 1 baby died due to pericardial tamponade secondary to an improperly placed PCVC. Pericardial tamponade is seen more often with the use of polyethylene and other stiff catheters used for umbilical catheteriza-tion and percutaneous central line(6). Although rare, recent reports have shown that pericardial effusions can also occur with the use of pliable silastic catheters in extremely low birth weight infant(6,7). Thrombotic complications are usually rare with the properly placed catheters. In our series, we encountered thrombotic complica-tions in 5 catheters (11%) and in 3 of these, the catheter tip could not be advanced properly into the major vessels. This placement failure rate of 7% (3/44) is comparable to the rate of 4% reported by other authors(8). Although local thrombosis was suspected in these 5 patients due to high pressures in the infusion pumps, none of the catheters were associated with deep caval thrombosis. The incidence of these complications may vary according to the site of insertion; scalp or arm veins (superior vena cava) and leg veins (inferior vena cava). Inferior vena cava catheters are less optimal and are associated with an increased risk of thrombosis and sepsis(7). Central venous pressures with these also tend to be unreliable. If this route is necessary, the tip should be positioned beyond the renal veins below the right atrium so that the blood flow of the renal veins can reduce the risk of thrombosis. The most optimum site of insertion would be the arm vein with the tip of the catheter placed high in the SVC. Most studies have focused attention to the use of these catheters in low birth weight preterm neonates. We have described success-ful catheter insertion in a large number of very small infants (23 infants weighing below 1000 grams and 9 babies weighing below 750 grams). With improving neonatal care and the advent of newer modalities such as surfactant therapy, more ELBW infants are expected to survive and require prolonged intravenous fluid and parenteral nutrition therapy. We conclude that CVC can be used safely to deliver total parenteral nutrition to extremely small preterm infants over a prolonged period of time. Staff education and formulation of standard guidelines for CVC care would help in elimination of catheter related complica-tions. We recommend using the arm veins for insertion of CVC. The tip of the catheter should be confirmed by X-ray to be high in the SVC, from where migration into the pericardium is unlikely. Contributors: RA was responsible for designing the study, data collection and drafting the manuscript. RA will act as the guarantor for the study. LD was responsible for interpretation of the data and revising the manuscript. Funding: None. Competing interests: None stated.
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
