Umbilical arterial catheter duration as risk factor for Bell's Stage III necrotizing enterocolitis in preterm neonates.

Objectives: To explore risk factors for Stage-III necrotizing enterocolitis (NEC-III) in preterm neonates. Methods: This was a retrospective case-control study of neonates born <33 weeks gestational age (GA) who were admitted to a tertiary neonatal intensive care unit, between 2015 and 2018. NEC-III cases were compared with Stage-II NEC (NEC-II) and non-NEC controls. Two to four non-NEC controls were matched by GA ± 1 week and date of birth ± 3 months, to one NEC-III case. Univariate and multivariate analyses were used to examine risk factors for NEC-III. Results: Of 1360 neonates born <33 weeks, 71 (5.2%) had NEC-II and above, with 46% being NEC-III. Mean age of onset of NEC-III was 13.7 days versus 23.9 days for NEC-II (p = 0.01). Neonates with NEC-III were of lower GA (NEC-III 25.4 weeks, NEC-II 27.3 weeks, and non-NEC 26 weeks; p = 0.0008) and had higher Score for Neonatal Acute Physiology Perinatal Extension-II scores (NEC-III 47.5, NEC-II 28.4 and non-NEC 37, p = 0.003). Multivariate analysis showed duration of umbilical arterial catheter (UAC) >5 days was significantly associated with the development of NEC-III with adjusted odds ratio (AOR) 3.8; 95% confidence interval (CI) (1.05-13.66) for NEC-III versus non-NEC and AOR 5.57; 95% CI (1.65-18.73), p = 0.006 for NEC-III versus NEC-II. Rupture of membranes (ROM) >1 week was associated with NEC-III (AOR 6.93; 95% CI [1.56-30.69] vs. non-NEC and AOR 11.74; 95% CI [1.14-120.34] vs. NEC-II). Conclusion: The increased association of NEC-III with duration of UAC and ROM could be further examined in prospective studies, and an upper limit for UAC duration could be considered in NEC prevention bundles.

Adverse events associated with umbilical vascular catheters in the neonatal intensive care unit: A retrospective cohort study.

BACKGROUND: Umbilical catheters are commonly inserted in newborns in the neonatal intensive care unit (NICU) yet are associated with serious adverse events (AEs) such as malposition, migration, infection, thrombosis, hepatic complications, cardiac effusion, and cardiac tamponade. There is a need to determine the incidence and risk factors for AEs to inform safe practice. OBJECTIVES: The objective of this study was to determine the incidence and risk factors for AEs (all-cause and individual types) associated with umbilical venous catheters (UVCs) and umbilical arterial catheters (UACs) in the NICU. METHODS: A retrospective cohort study was conducted in an Australian level-VI NICU over a 3-year period. Any newborn who had both a UVC and UAC insertion attempt was included. RESULTS: There were 236 neonates who had 494 catheters (245 UVCs and 249 UACs). Of these, 71% of UVCs (95% confidence interval [CI]: 65.6-76.9%; incidence rate: 181.1-237.3 per 1000 catheter days) and 43.8% of UACs (95% CI: 38-50.5%; incidence rate: 102.0-146.3 per 1000 catheter days) were associated with an AE. The most common AE was malposition on first X-ray for UVCs (60.1%, 95% CI: 55.1-67.3) and UACs (32.6%, 95% CI: 26.8-39.6). A dwell time of ≥7 days was a significant predictor of UAC failure (incidence risk ratio: 1.5, 95% CI: 1.1-2.1, p = 0.006) and migration of the UVC (incidence risk ratio: 3.5, 95% CI: 1.0-11.5, p = 0.043). CONCLUSION: Adverse events related to insertion occurred in a relatively high percentage of umbilical catheters placed. Increased dwell time remains a significant risk factor for catheter migration and overall failure. Practice change and consideration of risk factors for both individual and overall AE risk are necessary to reduce complications.

Percutaneous retrieval of embolized umbilical arterial catheter in extreme premature infant.

BACKGROUND: Umbilical arterial catheterization is a common procedure performed on critically ill neonates, especially those with extreme prematurity. Various complications have been described following umbilical artery catheter (UAC) placement including thrombosis, embolism, vasospasm, vascular perforation, hemorrhage, and infection. However, treatment of these complications is challenging due to the small size of this very fragile subset of patients. METHODS: A 3-day old extremely preterm infant was referred to our institution for percutaneous removal of a fragmented and embolized umbilical arterial catheter. RESULTS: Catheter retrieval was successful via a carotid approach utilizing techniques from percutaneous closure of PDA in preterm infants and trans-carotid access for PDA stent and aortic interventions. CONCLUSION: This case report describes the successful percutaneous retrieval of an embolized UAC fragment in an extremely preterm infant, the smallest documented in literature to date.

Clinical application and complication analysis of umbilical arterial catheterization in premature infants / 中国新生儿科杂志

Objective:To study the clinical application and complications of umbilical arterial catheterization (UAC) in premature infants.Methods:From January 2021 to December 2022, premature infants with UAC successfully inserted in NICU of our hospital were enrolled. According to birth weight (BW), the infants were assigned into three groups: <1 000 g, 1 000~1 499 g and ≥1 500 g. The perinatal data, UAC usage, UAC-related complications and risk factors of UAC-related complications were retrospectively analyzed.Results:A total of 39 premature infants received UAC, with gestational age 29.3(27.3, 30.4) weeks and BW 1 100 (900, 1 310) g. The insertion length (IL) of UAC was calculated using the average value of two formulas: a, IL (cm) =4×BW (kg) +7; and b, IL(cm) =3×BW (kg)+9. The accuracy of tube end position was determined using chest/abdomen radiography. 30(76.9%) cases had accurate position, 6(15.4%) had higher position and 3(7.7%) had lower position. The proportion of appropriately positioned tube end in <1 000 g, 1 000~1 499 g and ≥1 500 g groups were 80.0%, 76.5% and 71.4%, respectively, without statistically significant differences ( P>0.05) .No significant differences existed among the three groups in UAC duration and UAC routinely removal rate ( P>0.05). 9 cases (23.1%) of UAC were removed for specific reasons, including 4 cases of arterial spasm, 2 cases of withdrawal of treatment, 1 case of tube end displacement, 1 case of abdominal distension and 1 case of death. 21 cases received 1 U/ml heparin (0.9%NaCl solution) 0.5~1 ml/h arterial infusion. 23.8% (5/21) had hypernatremia and the level of sodium became normal after reducing the concentration of NaCl solution. Arterial vasospasm occurred in 4 patients with skin color changes of one side of the lower extremities. After UAC removal, the skin color returned to normal. Conclusions:UAC is helpful and safe for preterm infants, however, its complications should be alerted to.

Off label use of PICC as umbilical arterial catheter: Clinical case series.

Umbilical arterial catheters are often placed at birth in critical ill neonates. Advantages of umbilical arterial catheterization include continuous blood pressure monitoring, accurate blood gas and frequent blood samplings. We described the off-label use of a third generation polyurethane power injectable 3 Fr single lumen peripheral inserted central catheter as umbilical arterial catheter. This clinical case series opens new scenarios about the off-label use of power PICC in newborns. Prospective studies are needed to evaluate the safety and advantages of PICCs as umbilical catheters over the conventional old generation polyurethane neonatal catheters.

Risk factors for umbilical vascular catheter-related adverse events: A scoping review.

INTRODUCTION: Adverse events associated with umbilical catheters include malposition, bloodstream infections, thrombosis, tip migration, and extravasation, resulting in loss of vascular access and increased risk of morbidity and mortality. There is a need for greater understanding of risk factors associated with adverse events to inform safe practice. OBJECTIVES: The aim of the study was to summarise the existing evidence regarding risk factors for umbilical catheter-related adverse events to inform the undertaking of future research. REVIEW METHOD USED: A scoping review of peer-reviewed original research and theses was performed. DATA SOURCES: The US National Library of Medicine National Institutes of Health, Embase, EMcare, and ProQuest Dissertations and Theses were the data sources. REVIEW METHODS: Informed by the Joanna Briggs Institute Reviewer's Manual, all types of original research studies reporting adverse events published in English from 2009 to 2020 were eligible for inclusion. Studies where umbilical artery catheter and umbilical venous catheter data could not be extracted separately were excluded. RESULTS: Searching identified 1954 publications and theses, 1533 were excluded at screening, and 418 were assessed for eligibility at full text. A total of 89 studies met the inclusion criteria. A range of potential risk factors for umbilical arterial and venous catheters were identified. Longer dwell time and prematurity were associated with increased risk of bloodstream infection and thrombosis in cohort studies. Case studies detailed analogous factors such as insertion techniques and lack of catheter surveillance during dwell warrant further investigation. CONCLUSIONS: We identified a vast range of patient, device, and provider risk factors that warrant further investigation. There was a lack of large cohort studies and randomised controlled trials to demonstrate the significance of these risk factors. Improvement in methods to ensure correct catheter tip location and to detect adverse events early is essential. In addition, policy needs to be developed to guide clinicians in catheter surveillance measures to reduce the risk of adverse events.

Neonatal necrotizing enterocolitis caused by umbilical arterial catheter-associated abdominal aortic embolism: A case report.

BACKGROUND: Reports of necrotizing enterocolitis (NEC) caused by umbilical arterial catheter (UAC)-associated abdominal aortic embolism in neonates are rare. Herein, we report the case of an extremely low birth weight (ELBW) infant with NEC caused by UAC-associated abdominal aortic embolism. CASE SUMMARY: A female infant, aged 21 min and weighing 830 g at 28+6 wk of gestational age, was referred to our hospital because of premature birth and shallow breathing. The patient was diagnosed with ELBW, neonatal respiratory distress syndrome, neonatal intrauterine infection, and neonatal asphyxia. Umbilical arterial and venous catheters were inserted on the day after birth and were removed 9 d later, according to the doctor's plan. Within 48 h after extubation, the patient's manifestations included poor responsiveness, heart rate range of 175-185/min, and currant jelly stool. Therefore, we considered a diagnosis of NEC. To determine the cause, we used B-mode ultrasound, which revealed a partial abdominal aortic embolism (2 cm × 0.3 cm) and abdominal effusion. The patient was treated with nil per os, gastrointestinal decompression, anti-infective therapy, blood transfusion, and low-molecular-weight heparin sodium q12h for anticoagulant therapy (from May 20 to June 1, the dosage of low-molecular-weight heparin sodium was adjusted according to the anti-Xa activity during treatment). On the 67th day after admission, the patient fully recovered and was discharged. CONCLUSION: The abdominal aortic thrombosis in this patient was considered to be catheter related, which requires immediate treatment once diagnosed. The choice of treatment should be determined according to the location of the thrombus and the patient's condition.

Umbilical catheter rupture: A serious complication in neonatal intensive care units.

Umbilical catheterization is commonly used as a route to provide medications and fluids to the neonates as well as for blood sampling and continuous monitoring. Although the rupture of umbilical catheters is considered as a rare, preventable complication, it has been reported several times in the literature. Healthcare providers need to be cautious with catheter placement, maintenance, and removal to prevent such a complication. Hereby, we review the literature about this complication after presenting two incidents of umbilical venous catheter rupture in two separate patients in our neonatal ICU. One was removed easily through the umbilical stump, whereas the other required surgical exploration.

Bedside sonography performed by neonatology residents to confirm central vascular catheter position in neonates - A Prospective Diagnostic Evaluation study.

OBJECTIVE: To evaluate the diagnostic accuracy and utility of bedside ultrasound (US) by neonatology residents to confirm position of umbilical venous catheter (UVC), umbilical arterial catheter (UAC), and peripherally inserted central catheter (PICC). METHODS: In this prospective study, we included neonates who required UVC, UAC or PICC insertion. Two neonatology residents performed all bedside US examinations after a short period of training. Plain radiograph was taken as gold standard. Time taken for confirmation of catheter position by US and radiograph was recorded. RESULTS: We recruited 71 neonates for UVC and UAC, and 40 neonates for PICC. Sensitivity and specificity of US in identifying a malpositioned catheter was good for UVC (94% and 66.7% respectively) and UAC (86.7% and 94.5%). Agreement between radiograph and US was good for UVC [0.718 (0.512, 0.861); p < 0.001] and UAC [0.857 (0.682, 0.953); p < 0.001]. Sensitivity (47.8%) of US in identifying a malpositioned PICC was low, though specificity (82.4%) was good. Agreement between radiograph and US in identifying PICC position was poor [0.25 (-0.084, 0.545); p 0.024]. This was due to incorrect interpretation of catheter position on radiograph in some infants, which was confirmed by the radiologist. The median time taken for US was significantly less than time taken for radiograph in confirming the position of UVC (50 vs. 155 minutes; p < 0.001)), UAC (45 vs. 128 minutes; p < 0.001), and PICC (60 vs. 136 minutes; p < 0.001). CONCLUSION: US examination byneonatology residents has good diagnostic accuracy in confirming the position of UAC and UVC, and possibly PICC in neonates. The time taken to confirm catheter position by US is significantly less than radiograph.

Neonatal Umbilical Arterial Catheter Removal Is Accompanied by a Marked Decline in Phlebotomy Blood Loss.

BACKGROUND: Umbilical arterial catheters (UACs) are frequently used in critically ill neonates. UAC are convenient, reliable, and allow for caregiver convenience in performing painless arterial blood sampling. We hypothesized that UAC removal in extremely low birth weight (ELBW) neonates will result in significantly less phlebotomy blood loss (PBL) after correcting for severity of illness. STUDY DESIGN AND METHODS: PBL was measured at a single center in 99 ELBW infants who survived to day 28. Individual infant's paired daily PBL for the two 24-h periods before and after UAC removal were compared using the paired t test. Daily PBL up to 7 days before and 7 days after UAC removal were compared using a logistic regression with mixed model analysis for repeated measures. Cumulative 28-day phlebotomy loss was evaluated by multiple linear regression analysis. RESULTS: PBL 24 h before and after UAC removal were 1.7 mL (95% CI 1.5-1.9) and 0.9 mL (95% CI 0.8-1.0; p < 0.0001), respectively. Cumulative 28-day PBL increased by 2.2 mL (±0.7) per day that a UAC was present with or without correction for severity of illness (p < 0.001). CONCLUSION: UAC removal is independently associated with a marked decline in PBL. We speculate the ease and convenience of UAC blood sampling lead to more frequent blood testing and greater PBL.

Are there changes to regional tissue oxygenation and circulation following umbilical artery catheter placement? A prospective cohort study in newborn infants.

AIM: The use of umbilical arterial catheters (UACs) is a standard of care in monitoring critically unwell infants. Serious vascular complications are rare but when they do occur, they can be associated with significant morbidity, risking limb loss or even death. Near infra-red spectroscopy has the potential to monitor limb perfusion. Our study investigates changes in tissue oxygenation and perfusion in the abdominal and leg circulation following UAC insertion. METHODS: A prospective observational study performing ultrasound pulsed Doppler measurements in the coeliac, superior mesenteric artery, renal arteries and the femoral arteries as well as near infrared spectroscopy measurements of both thighs at three time points (immediately before = Time 1, 1 h after = Time 2 and 24 h after UAC insertion = Time 3). RESULTS: We monitored 30 infants, the mean gestational age was 30 weeks (24-41) and the mean birthweight was 1720 g (600-4070 g). We observed statistically significant changes (P < 0.05) in pulse Doppler measurements in coeliac (mean peak systolic velocity (PSV): Time 1 = 70.51, Time 2 = 61.75; resistive index (RI): Time 1 = 0.75, Time 2 = 0.67), superior mesenteric (PSV: Time 1 = 41.72, Time 2 = 36.10; RI: Time 1 = 0.92, Time 2 = 0.87), renal (same side end-diastolic velocity: Time 1 = 1.98, Time 2 = 3.80; RI: Time 1 = 0.93, Time 2 = 0.87; opposite side end-diastolic velocity: Time 1 = 2.62, Time 2 = 3.84; RI: Time 1 = 0.92, Time 2 = 0.85) and femoral arteries (same side PSV: Time 1 = 72.75, Time 2 = 62.18; opposite side PSV: Time 1 = 81.89, Time 2 = 62.74). Tissue oxygenation in lower limbs remained unaffected (same side (mean): Time 1 = 68.59, Time 2 = 68.99, Time 3 = 66.40, opposite side: Time 1 = 67.72, Time 2 = 66.92, Time 3 = 65.40). All infants on clinical examination had normal lower limb perfusion, lower limb arterial pulses and normal perfusion to the gluteal region before and after insertion of UAC. CONCLUSIONS: While sub-clinical changes in perfusion occur in abdominal and leg circulation, these changes are not consistent across vessels and regional tissue oxygenation remains unaffected.

A novel use of ultrasound for the extraction of a fractured umbilical arterial catheter.

A 7-day-old 600 grams baby with a post-conceptual age of 29 weeks presented with features suggestive of hollow viscous perforation, and was posted for an emergency laparotomy. In addition, she had a fractured indwelling umbilical arterial catheter which was planned for extraction in the same sitting. Radiological imaging showed that the catheter extended into the stump of the umbilical cord. She underwent exploratory laparotomy and ileal resection anastomosis, following which the stump was explored. However, the catheter could not be identified, and we suspected that it had embolised into the aorta. Using ultrasound guidance, we identified the catheter within the aorta. The aorta was cross-clamped, and the catheter extracted through an aortotomy which was later sutured.

Accuracy of 11 formulae to guide umbilical arterial catheter tip placement in newborn infants.

BACKGROUND: Umbilical arterial catheter (UAC) insertion is a common procedure in the neonatal intensive care unit (NICU). Correct placement of the tip of the UAC at first attempt minimises handling of the infant and reduces the risk of infection and complications. We aimed to determine the accuracy of 11 published formulae to guide UAC placement. METHODS: This was a one-year prospective observational study in a tertiary NICU. Clinicians used their preferred formula for UAC insertion, with X-rays performed immediately post-procedure to check the tip position. Birth weight and measurements included in the 11 formulae were recorded within 48 hours. The gold standard insertion distance was defined as the distance from the abdominal wall to the mid-descending aorta, at T8 level on X-ray (range T6-T10). Insertion length using the 11 formulae was calculated and compared with this gold standard distance. RESULTS: One hundred and three infants were included, with median (IQR) gestational age and weight of 28 (26-33.5) weeks and 980 (780-2045) g, respectively. The predicted value of the 11 formulae to place the UAC in correct position ranged from 51.0% to 73.8%. Formulae that involved direct body part measurements showed the highest predicted success rates, smallest mean difference from T8 and narrowest limits of agreement using the Bland-Altman method. CONCLUSION: Success rates for accurate UAC placement are highest when formulae that involve body measurements are used. However, even the most accurate method would result in more than 25% of UACs needing manipulation to achieve an optimal position.

Optimal Line and Tube Placement in Very Preterm Neonates: An Audit of Practice.

BACKGROUND: Placement of endotracheal tubes (ETTs) and umbilical catheters (UCs) is essential in very preterm infant care. The aim of this study was to assess the effect of an educational initiative to optimize correct placement of ETTs and UCs in very preterm infants. METHODS: A pre-post study design, evaluating optimal radiological position of ETTs and UCs in the first 72 h of life in infants <32 weeks gestational age (GA) was performed. Baseline data was obtained from a preceding 34-month period. The study intervention consisted of information from the pre-intervention audit, surface anatomy images of the newborn for optimal UC positioning, and weight-based calculations to estimate insertion depths for endotracheal intubation. A prospective evaluation of radiological placement of ETTs and UCs was then conducted over a 12-month period. RESULTS: During the study period, 211 infants had at least one of the three procedures performed. One hundred and fifty-seven infants were included in the pre-education group, and 54 in the post-education group. All three procedures were performed in 50.3% (79/157) in the pre-education group, and 55.6% (30/54) in the post-education group. There was no significant difference in accurate placement following the introduction of the educational sessions; depth of ETTs (50% vs. 47%), umbilical arterial catheter (UAC) (40% vs. 43%,), and umbilical venous catheter (UVC)(14% vs. 23%). CONCLUSION: Despite education of staff on methods for appropriate ETT, UVC and UAC insertion length, the rate of accurate initial insertion depth remained suboptimal. Newer methods of determining optimal position need to be evaluated.

Estimating umbilical catheter insertion depth in newborns using weight or body measurement: a randomised trial.

OBJECTIVE: Incorrectly positioned umbilical venous and arterial catheters (UVC and UAC) are associated with increased rates of complications in newborns. Catheter insertion depth is often estimated using body surface measurement. We wished to determine whether estimating insertion depth of umbilical catheters using birth weight (BW), rather than surface measurements, results in more correctly positioned catheters. INTERVENTIONS/OUTCOME: Newborns were randomised to have UVC and UAC insertion depth estimated using formulae based on BW or using graphs based on shoulder-umbilicus length. The primary outcome was correct catheter tip position on X-ray determined by one radiologist masked to group assignment. RESULTS: UVC insertion was successful in 97/101 (96%) infants but the catheter was not advanced to the estimated depth in 22. There was no difference in the proportion of correctly positioned UVCs between groups (weight 16/51 (31%) vs measurement 13/46 (28%), p=0.826). The tips of 52 (54%) UVCs were in the portal venous system or too low on X-ray. Attempted UAC insertion was successful in 62/87 (71%) infants. More infants in the weight group had a correctly positioned UAC tip (weight 29/32 (91%) vs measurement 15/30 (50%), p=0.001). CONCLUSIONS: UVCs were often not inserted to the estimated depth, and their tips were in the portal venous system or too low on X-ray. Using BW to estimate insertion depth did not result in more correctly positioned UVCs. UAC insertion attempts were often unsuccessful, but when successful, using BW to estimate insertion depth resulted in more correctly positioned catheters. TRIAL REGISTRATION NUMBER: (ISRCTN17864069).

Comparison of Wright's formula and the Dunn method for measuring the umbilical arterial catheter insertion length.

BACKGROUND: Umbilical artery catheterization is the standard procedure for arterial access in neonatal intensive care units. An umbilical arterial catheter (UAC) needs to be placed accurately during the initial insertion because malpositioning increases catheter-related complications and subsequent repositioning exposes newborns to unnecessary handling, further radiologic exposure, and an increased risk of infection. To measure the UAC insertion length in newborns, we compared the conventional practice (i.e., the Dunn method) with a new formula: Wright's formula. METHODS: The study enrolled 119 newborns. A nomogram derived from Dunn was used during the first study period and the new formula devised by Wright (4 × birth weight + 7 cm) was used during the second study period. The catheter tip position on the initial radiograph was evaluated as correct (i.e., T6-T10), overinsertion (i.e., T10). RESULTS: The demographic profiles were not different between the two groups, which included sex; birth weight; and the number of preterm births, low-birth-weight (LBW) newborns, and very-low-birth-weight (VLBW) newborns. When using Wright's formula and the Dunn method, 83% of newborns and 61% of newborns, respectively, received a correct insertion (p < 0.05). The success rate for positioning the UAC tip between T7 and T8 was approximately two-fold higher when using Wright's formula than when using the Dunn method. In particular, the rate of correct insertion was significantly higher with Wright's formula in term newborns, LBW newborns, VLBW newborns, and small for gestational age (SGA) newborns (p < 0.05); however, the rate of overinsertion with the Dunn method was much higher in term newborns, LBW newborns, VLBW newborns, and SGA newborns (p < 0.05). CONCLUSION: The use of Wright's formula overall results in superior correct placement of the UAC tip. It may be a more accurate and practical method than the conventional practice for measuring the UAC insertion length in newborns.

Radiographic assessment of umbilical venous and arterial catheter tip location.

Umbilical venous and arterial catheters are routinely used in the care of critically ill patients in neonatal intensive care settings. Providers caring for these vulnerable patients have a role in ensuring that catheter tips remain in an appropriate position. The ideal anatomic tip location for both types of umbilical catheters is reviewed, and the evaluation of this position via radiographic study is discussed. Umbilical venous catheters (UVCs) and umbilical arterial catheters (UACs) have their own different complications. Complications of a malpositioned catheter of either type can be life threatening; therefore, evaluation of catheter tip location is an important skill in the provision of neonatal intensive care.

Impact of umbilical catheterization on morbidity and mortality in extremely premature newborns.

OBJECTIVE: Investigate the benefit of umbilical catheterization upon survival and selected morbidities in extremely premature newborns (<28 weeks gestation). Outcomes of successfully catheterized extremely premature newborns are compared with others who cannot be successfully catheterized, and we hypothesize that umbilical catheterization promotes survival and reduces morbidities. STUDY DESIGN: Utilizing a retrospective, cohort study design, survival and outcomes of catheterized and non-catheterized newborns (n = 722) were compared by univariate and multiple logistic regression analyses. RESULTS: Of all newborns, 66.8% had both umbilical arterial catheter (UAC) and umbilical venous catheter (UVC) placements, 15.0% had only UAC, 13.7% had only UVC, and 4.6% had neither. Overall survival was 82.5%. Survivals with and without UAC were 82.5% and 82.6% (NS), but survival with UVC was 80.7% versus 90.1% without UVC (p = 0.012). Analysis of risk factors associated with death during umbilical catheterization reaffirmed that death remained significantly dependent upon UVC placement (OR = 35.7; 95% CI: 3.7-347.3, p = 0.002). CONCLUSION: Successful umbilical catheterization of extremely premature newborns does not provide benefit through promotion of survival or reduction of morbidities when compared to others who are not successfully catheterized at the umbilicus.

Effects of Umbilical Arterial Catheterization on Intestinal Hemodynamics

PURPOSE: An umbilical arterial catheter (UAC) in the high position reduces the lumen of the aorta and may thereby impair blood supply to the intestine. Effects of UAC on intestinal blood flow were investigated. METHODS: With the measurement of the aortic diameter, pulsed Doppler ultrasonography was performed in 23 fasting newborns to measure blood flow velocities (peak systolic velocity, end-diastolic velocity, mean velocity, time velocity integral and resistive index) in the celiac trunk (CT) and the superior mesenteric artery (SMA) before and after removal of the UAC in the high position. RESULTS: UAC reduced the cross-sectional area of the aorta by 3.5-15.0% (mean 7.5%), with the percentage of reduction being inversely related to birth weight (r=-0.86, P<0.0001). Blood flow velocities in the CT and the SMA did not change significantly after removal of the UACl left in place for 7 days. There were also no differences in blood flow velocities pre- and postremoval of the UAC which stayed in place for 17.3 days and caused a mean aortic obstruction of 11.7%. However, a longer indwelling time of the UAC may lead to a higher velocity in the CT with UAC in place, as reflected by a correlation by multiple regression analysis (r=0.42, P=0.045). CONCLUSION: Although UAC remaining in place for up to 2 weeks in fasting newborns does not lead to direct alterations in blood supply to the intestine, the possibility of blood flow impairment to abdominal organs by prolonged use cannot be excluded.