Determination of umbilical venous catheter tip position with radiograph.

OBJECTIVES: To compare the cardiac silhouette method with the vertebral body method in predicting the umbilical venous catheter tip position on ultrasound; to measure the length of the target zone for the umbilical venous catheter tip; and to determine the time taken for a neonatologist to ascertain position of the umbilical venous catheter tip with ultrasound. DESIGN: Prospective cohort study. SETTING: Neonatal ICU. PATIENTS: Newborn infants with an umbilical venous catheter. INTERVENTIONS: Ultrasound scans to determine the umbilical venous catheter tip position were performed within an hour of corresponding anteroposterior chest-abdominal radiograph. MEASUREMENTS AND MAIN RESULTS: Two hundred paired radiograph and ultrasound scans in 82 newborn infants were analyzed. Each radiograph was reviewed independently by an experienced neonatologist who recorded the position of the umbilical venous catheter tip by vertebral level and by the cardiac silhouette method. For each method, the sensitivity, specificity, and positive and negative predictive values were calculated for the prediction of the true position of the catheter tip on ultrasound. The umbilical venous catheter tip was well positioned in just 28 of 200 scans. The cardiac silhouette method was superior to the vertebral level method for all test variables, with a sensitivity and specificity of 86% and 94% compared with 61% and 74%. The length of the target zone approximates to a single T8 vertebral body height on radiograph. CONCLUSIONS: For radiograph and ultrasound scans performed within an hour of each other, the cardiac silhouette method more accurately predicts umbilical venous catheter tip than vertebral body level and methods described in previous studies. Catheters are frequently malpositioned. The length of the target zone for optimal umbilical venous catheter tip position is short. Ultrasound assessment of umbilical venous catheter tip position is quick.

Relationship between blood culture collection method and proportion of contaminated cultures in neonates.

AIM: This study aims to document methods of blood culture collection used in our neonatal unit and to determine whether or not the proportion of contaminated cultures varied according to method of collection. Two specific comparisons of interest were the proportion of contaminated cultures in samples collected via (i) preferred versus non-preferred methods, and (ii) peripheral cannulae at the time of insertion versus separate arterial or venous puncture. METHODS: Data were collected on every blood culture taken in the Grantley Stable Neonatal Unit of the Royal Brisbane and Women's Hospital over a 12-month period. The method used to collect blood for culture was recorded, and the proportion of contaminated cultures taken by each method was calculated. RESULTS: Blood was collected via peripheral cannulae at the time of insertion in 63.1% of cultures, umbilical catheters at the time of insertion in 18.1%, peripheral arterial or venous puncture in 7.7%, and indwelling lines in 2.1%, and the method was unknown in 9.0%. The proportion of contaminated blood cultures was 11.5% with collection via peripheral vascular puncture, 11.1% via indwelling lines, 2.1% via peripheral cannulae at the time of insertion and 1.1% via umbilical catheters at the time of insertion. There was no significant difference in the proportion of contaminated cultures taken via preferred and non-preferred methods. The proportion of contaminated cultures taken via peripheral cannulae at the time of insertion was significantly less than when samples were taken via a separate arterial or venous puncture. CONCLUSIONS: In our unit, blood cultures are frequently collected via peripheral cannulae at the time of insertion. Blood cultures taken in this manner are less likely to be contaminated than cultures collected via separate vascular puncture.

The management of patent ductus arteriosus in Australia and New Zealand.

AIM: This study aimed to establish current management practice for patent ductus arteriosus (PDA) among individual consultant neonatologists in Australia and New Zealand, to examine the influences that drives practice and highlight the importance of future randomised controlled trials in the region. METHODS: Eligible subjects were identified from the Directory of Neonatal Intensive Care Units in Australia and New Zealand, 2007. A questionnaire was sent online to each consultant and was followed up with a letter and telephone call. Seven questions addressed management approach, the drug used and the treatment regimen, threshold for referral for surgical ligation and the literature influencing practice. Data were collected from 22 August 2007 to 22 November 2007. RESULTS: The overall response rate was 95%. For infants < or =28 weeks or < or =1000 g, all consultants treat PDA by one of four distinct management approaches. Expectant management was favoured by 35%, echocardiographic targeted prophylaxis 32%, presymptomatic treatment 16% and prophylaxis by 17%. There were marked regional variations in practice. Within individual units, more than one approach is used in 14 out of 24 units. Long courses of indomethacin are used to treat PDA by 86%. For 22% of consultants, management is not influenced by published literature. CONCLUSIONS: Differences of opinion in the literature are reflected by the heterogeneity in clinical practice across regions and within units. Crucial questions undergoing evaluation are whether data extrapolated from a previous area are relevant to PDA in modern neonatology and whether targeting treatment early can translate to improved clinical outcome.