SY Chiu, SY Ha, CF Chan, SSY Wong, KY Yuen, KL Chan, YL Lau

Abstract

A 2-year retrospective survey of the use of central venous catheter (CVC) was performed to review its use and complications. 47 CVCs (27 single-lumen catheters, 17 double-lumen catheters and 3 subcutaneous ports) were placed in 38 consecutive patients (age range 0.49-19, median 4.85 year). All except 2 CVCs were inserted through jugular veins under general anesthesia. The total lifespan of the CVCs was 8042 (median 149, range 9-572) days. The rate of documented catheter-related bacteraemia was 3.4 episodes /1 000 catheter days with a total of 28 episodes. The three most common organisms were Coagulase negative staphylococcus, Staphylococcus aureus and Bacillus cereus. The reasons for removal of CVC were cessation of indication in 13 (27%), death 8 (17%), catheter-related bacteraemia 8 (17%), exit site infection 7 (15%), dislodgment 7 (15%) and internal rupture 1 (2%). Three (7%) CVCs were still in use at the end of the study. Catheter-related infection remains the most important complication and the leading cause of CVC removal.

本文回顧性總結了兩年來中心靜脈插管(CVC)的使用及其併發症。連續38例患者（年齡由0.49至19歲，中位數 4.85歲）共接受了47次CVCs（27次單腔管，17次雙腔管，3次皮下囊包）。除兩次外，其餘均為全麻下經頸靜脈插管。總插管時間為8042天(中位數149天，範圍9-572天）。記錄到的與插管相關的菌血症發生率為每 1000插管日3.4次，共計發生28次。三種最常見的細菌分別為：凝固酶陰性的葡萄球菌、金黃色葡萄球菌和蜡樣芽胞杆菌。拔管原因為：插管指征消失13例（27%），死亡8例（17%），插管相關菌血症8例（17%）。插管外口感染7例（15%），插管移位7例（15%）以及皮內插管部份破裂1例（2%）。本研究結束仍有3例（7%） CVCs在使用中。與插管相關的感染仍然是最重要的併發症也是最主要的拔管原因。

Introduction

Central venous catheters are indicated for patients who require frequent or prolonged venous access, for administration of cytotoxic drug, intravenous fluid, antibiotics, blood products, parenteral nutrition; and blood sampling.^1,2 Its use in paediatric haematology / oncology unit has been increasing as it provides easier venous access, reduces the pain of venesection and the risk of extravasation. In 1991, Dawson reported their experience of the use of external CVC in paediatric haematology and oncology patients, and defined the catheter related sepsis as having one positive blood culture, or neutropenic fever even with negative blood culture; or subcutaneous tunnel infection.³ The infection rate of the catheter related sepsis was 2.1 episode /1000 catheter day. The most common organisms were Staphylococcus aureus and Staphylococcus epidermidis. Twenty percent of the external catheter was removed due to complications. In the same year, Ingram also reported their experience. CVC line infection was defined as line infection as having two positive blood cultures from the line with or without fever; tunnel/exit site/pocket infection as inflammation around the device or along catheter tunnel and a positive culture from the area.⁴ The rate of catheter related infection was 4.7/1000 for external catheters, and 0.7/1000 for subcutaneous ports. The most common organism was Staphylococcus epidermidis. Forty-four percent of the external catheters were removed due to complications.

The aim of our survey was to review the complications related to the use of CVCs in the paediatric haematology/ oncology unit at Queen Mary Hospital, Hong Kong.

Method

A retrospective study of CVCs which were inserted within the period of 1993 and 1994 in our haematology / oncology unit was carried out to review its utilization and complications till August, 1995. Case records concerning the use of each CVC and the complications arisen were reviewed. Blood and line culture results were retrieved from the computer database from the Microbiology Department. Catheter related bacteraemia was defined as patient with CVC having temperature > 38°C, at least one positive blood culture, and without other focus of infection. Exit site infection was defined as having at least one positive exit site swab culture and sign of local infection.

Results

Between 1993 and 1994, a total of 47 CVCs were inserted in 38 consecutive patients, including 27 single lumen catheters, 17 double lumen catheters, and 3 subcutaneous ports. Seven patients had more than one CVC inserted within this period. Six of them had two and one had four times of line insertion.

The patients' age ranged 0.49 to 19 year (median 4.85 years). Their disease entities were shown in Table. Twenty-five (53%) were male and 22 (47%) were female. The total lifespan of the CVCs was 8042 days, with a range from 9 to 572, and median 149 days. The indications were chemotherapy (49%), bone marrow transplantation (38%) and others such as total parenteral nutrition, blood product and medication administration (13%). The insertion was through jugular veins under general anesthesia by open method with the creation of subcutaneous tunnel, except 2 CVCs.

There were 28 episodes of catheter related bacteraemia in 22 CVCs, giving an infection rate of 3.4 episode / 1000 catheter day. There were a total of 39 causative organisms associated with catheter related bacteraemia. Five (18%) of the cultures from CVCs yielded mixed growth of organisms. The infective agents were catergorised and shown in Figure 1. Staphylococcus aureus, Coagulase negative staphylococcus and Bacillus cereus, which are common skin pathogens, were the most commonly found organisms (60%). The rate of catheter related bacteraemia in different diagnoses were also shown in Table. Twenty episodes (71%) of catheter related bacteraemia were successfully treated with antibiotics and without removal of the CVC.

Fig. 1 Causative organisms in catheter-related bacteraemia Staphy: Coagulase negative staphylococcus, Staphylococcus aureus, Staphylococcus epidermidis, staphylococcus haemolyticus. Non-fermenter: Pseudomonas aeruginosa, Acinetobacter iwoffii, Agrobacterium radiobactor, Flavo meningosepticum, Acinetobacter anitratus, Achrombacter, Pseudomonas maltophilia. Bacillus: Bacillus cereus, Bacillus species, Diphtheria bacilli, Bacillus circulans. Enterobac. & Vibrion.: Klebsiella pneumoniae, Aeromonas caviae, Enterobacter cloacae. Strept. sanguis

Twelve (26%) CVCs were complicated by external rupture and subsequently repaired. Majority of this complications (11 episodes) were caused by infusion pump, and 1 episode due to cracking at the hub site. All of the occlusion were salvaged by urokinase. None of them led to removal. One CVC was removed due to internal rupture, causing leakage into the subcutaneous tissue. It was irreparable and required line removal. Seven (15%) CVCs were removed due to dislodgment and all the patients were below 5 year of age. The catheter day ranged from 9 to 320, with median 17. In one instance, the catheter tip migrated to right ventricle and the patient complained of chill during line flushing. Surgical intervention for repositioning was subsequenlty performed.

This report did not address the exit site infection rate and the occlusion rate. The outcome of central venous catheter is shown in Figure 2. Forty-eight percent of the CVCs was removed due to complications. Staphylococcus aureus and Coagulase negative staphylococcus accounted for the majority (n=5), followed by Pseudomonas maltophilia (n= 2) in 7 CVC removal due to exit site infection. Bacillus Cereus accounted for 6 of the 8 CVCs which were removed due to bacteraemia. Three CVCs were still in use at the end of the study.

Fig. 2 Outcome of the CVC

Discussion

The use of CVC in paediatric haematology/oncology unit has been increasing over the past decade. However its use is associated with various complications. Infection is the most serious complication of CVC.^2,5,6 Twenty-two (47%) of the CVCs in our series had a history of catheter related bacteraemia. Staphylococcus aureus and Coagulase negative staphylococcus were the most common causative organisms of catheter related bacteraemia and these findings were similar to other studies.^2,3,6 Catheter related bacteraemia due to Bacillus cereus is difficult to clear and accounted for most of the premature catheter removal. Therefore, strategies for prevention and treatment of infections are essential in improving results.⁷ Standard protocol, staff education and continuous monitoring in the use and care of the CVC should be emphasized.

Patients with solid tumours had a lower rate of catheter related bacteraemia in the study which may be related to the lesser degree of the immunosuppression and duration of neutropenia. Infection rate usually increases with longer duration and more severe neutropenia.^2,3,6,7

Most of the mechanical complications were avoidable. In our study, the dislodgment of catheters occurred mainly in younger children and newly inserted catheters. In order to prevent early dislodgment, it is important to secure the catheter properly. Tissue ingrowth into the Dacron cuff will prevent accidental dislodgment, but it takes time and is affected by the patient's nutritional status, immunocompetence, and treatment received (such as steroid effect), and local infection.¹ Hence, the anchoring stitch is recommended to remain for longer period after insertion of CVC. Close dressing is advised for high risk patients. The external rupture of catheter could be reduced with the use of pressure monitoring infusion pump.

In conclusion, the use of CVC is safe and most complications can be managed.^2,3 Catheter related infection remains the most important complication and the leading cause of removal. Strategies for the prevention of infection and mechanical complications are essential for the optimal use of CVC.

Acknowledgment

We wish to thank Ms Patricia Ching, Senior Nursing Officer, Ms Frances Chung, Nursing Officer, of Infection Control Unit for their generous help. Thanks are also directed to Ms Julie Fung, Ward Manager in Paediatric Unit, and all nursing staff of Paediatric Haematology/Oncology ward, in Queen Mary Hospital for their support.

References

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2. Gleason-Morgan D, Church JA, Bagnall-Reeb H, Atkinson J. Complications of central venous catheters in pediatric patients with acquired immunodeficiency syndrome. Pediatr Infect Dis J 1991;10:11-4.

3. Dawson S, Pai MKP, Smith S, Rothney M, Ahmed K, Barr RD. Right atrial catheters in children with cancer: a decade of experience in the use of tunnelled, exteriorized devices at a single institution, Am J Pediatr Hem/Oncol 1991;13:126-9.

4. Ingram J, Weitzman S, Greenberg ML, Parkin P, Filler R. Complications of indwelling venous access lines in the pediatric hematology patient : A prospective comparison of external venous catheters and subcutaneous port. Am J Pediatr Hem/ Oncol 1991;13:130-6.

5. Christensen ML, Hancock ML, Gattuso J, et al. Parenteral nutrition associated with increased infection rate in children with cancer. Cancer 1993;72:2732-8.

6. Gorelick MH, Owen WC, Seibel NL, Reaman GH. Lack of association between neutropenia and the incidence of bacteraemia associated with indwelling central venous catheters in febrile pediatric cancer patients. Pediatr Infect Dis J 1991;10:506-10.

7. Barr RD. Introduction : Use of tunneled right atrial catheters in children with malignant diseases. Am J Pediatr Hem/Oncol 1991;13:123-5.