Which criteria should be used to select patients for the Fontan operation?

The Fontan operation has improved the survival of children born with single ventricle physiology. Selecting candidates for the Fontan operation may be difficult on borderline cases. No clear criterion has been established on the risk for staged Fontan palliation. Another aspect that remains controversial is the indications for fenestration. Intraoperative pulmonary flow study may identify high-risk patients for the procedure. In this report, the authors describe their results with Fontan procedures in children with pulmonary pressure >15 mmHg.

Dilated cardiomyopathy in children: moving beyond traditional pharmacologic therapy.

PURPOSE OF REVIEW: Dilated cardiomyopathy (DCM) is a rare myocardial disorder characterized by a dilated left ventricle and systolic dysfunction. Globally, it affects around 1 in every 100 000 children. The prognosis is generally poor, with 40% either failing traditional medical therapy within the first 2 years or requiring a heart transplant. This article will address the basic cause, epidemiology, pathobiology, and historical treatment approach of DCM and introduce novel contemporary medical and surgical strategies that may reduce the need for heart transplantation. RECENT FINDINGS: In the last 15 years, there has been a significant emphasis on identifying alternative treatment strategies in managing the child with a DCM and heart failure symptoms. New therapies have evolved to help bridge these critically ill children to transplant or have these therapeutic modalities serve as end-points in themselves. Thus subsequently, we will highlight contemporary as well as novel medical and procedural therapies that are being used for the treatment of pediatric DCM. SUMMARY: The child with a DCM and severe left ventricular dysfunction has a number of options available beyond simple diuretics and afterload reduction. Novel pacing strategies and mechanical assist device may provide not only a more stable clinical bridge environment but also may actually serve as an endpoint itself.

Applying Educational Theory to Interdisciplinary Education in Pediatric Cardiac Critical Care.

At the 14th Annual International Meeting for the Pediatric Cardiac Intensive Care Society, the authors presented a simulation workshop for junior multidisciplinary providers focused on cardiopulmonary interactions. We provide an overview of educational theories of particular relevance to curricular design for simulation-based or enhanced activities. We then demonstrate how these theories are applied to curriculum development for individuals to teams and for novice to experts. We review the role of simulation in cardiac intensive care education and the education theories that support its use. Finally, we demonstrate how a conceptual framework, SIMZones, can be applied to design effective simulation-based teaching.

Inadequate oxygen delivery index dose is associated with cardiac arrest risk in neonates following cardiopulmonary bypass surgery.

AIM: To evaluate the Inadequate oxygen delivery (IDO2) index dose as a predictor of cardiac arrest (CA) in neonates following congenital heart surgery. METHODS: Retrospective cohort study in 3 US pediatric cardiac intensive units (1/2011- 8/2016). Calculated IDO2 index values were blinded to bedside clinicians and generated from data collected up to 30 days postoperatively, or until death or ECMO initiation. Control event data was collected from patients who did not experience CA or require ECMO. IDO2 dose was computed over a 120-min window up to 30 min prior to the CA and control events. A multivariate logistic regression prediction model including the IDO2 dose and presence or absence of a single ventricle (SV) was used. Model performance metrics were the odds ratio for each regression coefficient and receiver operating characteristic area under the curve (ROC AUC). RESULTS: Of 897 patients monitored during the study period, 601 met inclusion criteria: 29 patients had CA (33 events) and 572 patients were used for control events. Seventeen (59%) CA and 125 (26%) control events occurred in SV patients. Median age/weight at surgery and level of monitoring were similar in both groups. Median postoperative event time was 0.73 days [0.05-22.39] in CA patients and 0.82 days [0.08 25.11] in control patients. Odds ratio of the IDO2 dose coefficient was 1.008 (95% CI: 1.006-1.012, p = 0.0445), and 2.952 (95% CI: 2.952-3.258, p = 0.0079) in SV. The ROC AUC using both coefficients was 0.74 (95% CI: 0.73-0.75). These associations of IDO2 dose with CA risk remained robust, even when censored periods prior to arrest were 10 and 20 min. CONCLUSION: In neonates post-CPB surgery, higher IDO2 index dose over a 120-min monitoring period is associated with increased risk of cardiac arrest, even when censoring data 10, 20 or 30 min prior to the CA event.

Eighteen years of paediatric extracorporeal membrane oxygenation and ventricular assist devices: insight regarding late outcomes.

BACKGROUND: We reviewed all patients who were supported with extracorporeal membrane oxygenation and/or ventricular assist device at our institution in order to describe diagnostic characteristics and assess mortality. METHODS: A retrospective cohort study was performed including all patients supported with extracorporeal membrane oxygenation and/or ventricular assist device from our first case (8 October, 1998) through 25 July, 2016. The primary outcome of interest was mortality, which was modelled by the Kaplan-Meier method. RESULTS: A total of 223 patients underwent 241 extracorporeal membrane oxygenation runs. Median support time was 4.0 days, ranging from 0.04 to 55.8 days, with a mean of 6.4±7.0 days. Mean (±SD) age at initiation was 727.4 days (±146.9 days). Indications for extracorporeal membrane oxygenation were stratified by primary indication: cardiac extracorporeal membrane oxygenation (n=175; 72.6%) or respiratory extracorporeal membrane oxygenation (n=66; 27.4%). The most frequent diagnosis for cardiac extracorporeal membrane oxygenation patients was hypoplastic left heart syndrome or hypoplastic left heart syndrome-related malformation (n=55 patients with HLHS who underwent 64 extracorporeal membrane oxygenation runs). For respiratory extracorporeal membrane oxygenation, the most frequent diagnosis was congenital diaphragmatic hernia (n=22). A total of 24 patients underwent 26 ventricular assist device runs. Median support time was 7 days, ranging from 0 to 75 days, with a mean of 15.3±18.8 days. Mean age at initiation of ventricular assist device was 2530.8±660.2 days (6.93±1.81 years). Cardiomyopathy/myocarditis was the most frequent indication for ventricular assist device placement (n=14; 53.8%). Survival to discharge was 42.2% for extracorporeal membrane oxygenation patients and 54.2% for ventricular assist device patients. Kaplan-Meier 1-year survival was as follows: all patients, 41.0%; extracorporeal membrane oxygenation patients, 41.0%; and ventricular assist device patients, 43.2%. Kaplan-Meier 5-year survival was as follows: all patients, 39.7%; extracorporeal membrane oxygenation patients, 39.7%; and ventricular assist device patients, 43.2%. CONCLUSIONS: This single-institutional 18-year review documents the differential probability of survival for various sub-groups of patients who require support with extracorporeal membrane oxygenation or ventricular assist device. The indication for mechanical circulatory support, underlying diagnosis, age, and setting in which cannulation occurs may affect survival after extracorporeal membrane oxygenation and ventricular assist device. The Kaplan-Meier analyses in this study demonstrate that patients who survive to hospital discharge have an excellent chance of longer-term survival.

Risk Factors for Survival After Heart Transplantation in Children and Young Adults: A 22-Year Study of 179 Transplants.

BACKGROUND: This article reviews all patients who underwent heart transplantation (HTx) within a single institution (172 patients underwent 179 HTx [167 first-time HTxs, 10 second HTxs, 2 third HTxs]) to describe diagnostic characteristics, management protocols, and risk factors for mortality. METHODS: Descriptive analysis was performed for the entire cohort using mean, standard deviation, median, interquartile range, and overall range, as appropriate. Univariable and multivariable Cox proportional hazards models were performed to identify prognostic factors for outcomes over time. The primary outcome of interest was mortality, which was modeled by Kaplan-Meier analysis. RESULTS: Median age at HTx was 263 days (range, 5 days to 24 years; mean = 4.63 ± 5.95 years; 18 neonates, 79 infants). Median weight at HTx was 7.5 kg (range, 2.2-113 kg; mean = 19.36 ± 23.54). Diagnostic categories were cardiomyopathy (n = 62), primary transplantation for hypoplastic left heart syndrome (HLHS) or HLHS-related malformation (n = 33), transplantation after cardiac surgery for HLHS or HLHS-related malformation (n = 17), non-HLHS congenital heart disease (n = 55), and retransplant (n = 12). Operative mortality was 10.1% (18 patients). Cumulative total follow-up is 1,355 years. Late mortality was 18.4% (33 patients). Overall Kaplan-Meier five-year survival was 76.2%. One hundred twenty-one patients are alive with a mean follow-up of 7.61 ± 6.46 years. No survival differences were seen among the five diagnostic subgroups ( P = .064) or between immunosensitized patients (n = 31) and nonimmunosensitized patients (n = 141; P = .422). CONCLUSIONS: Excellent results are expected for children undergoing HTx with comparable results among diagnostic groups. Pretransplant mechanical circulatory support and posttransplant mechanical circulatory support are risk factors for decreased survival. Survival after transplantation for HLHS or HLHS-related malformation is better with primary HTx in comparison to HTx after prior cardiac surgery.

Hypothyroidism in Infants With Congenital Heart Disease Exposed to Excess Iodine.

Thyroid hormone is critical for neonatal brain development, and even transient hypothyroidism can cause adverse neurocognitive outcomes. Infants exposed to excess iodine are at risk of developing hypothyroidism, especially those with congenital heart disease (CHD), because they are routinely exposed to excess iodine from intravenous iodinated contrast media and topical antiseptics. The aim of the present study was to identify the proportion of neonates with CHD exposed to iodine who developed hypothyroidism and to identify the associated risk factors. This was a retrospective study of neonates undergoing cardiac catheterization at Boston Children's Hospital during a 3-year period, some of whom also underwent cardiac surgery. Hypothyroidism was defined as an elevated thyroid-stimulating hormone level (>20 mIU/L at 24 to 96 hours of age and >15 mIU/L at >96 hours of age by heel-stick sampling and >9.1 mIU/L at 1 to 20 weeks of age by serum testing). Multivariate logistic regression was performed to predict the odds of developing hypothyroidism. Hypothyroidism was diagnosed incidentally in 46 of 183 infants (25%) with CHD after iodine exposure. Controlling for baseline cardiac risk, postnatal age, and gestational age, we found a fourfold increase in odds of developing hypothyroidism in neonates with serum creatinine >0.9 mg/dL and a fourfold increase in those who underwent more than three procedures. Hypothyroidism in neonates with CHD exposed to excess iodine is associated with multiple procedures and impaired renal function. Routine serial monitoring of thyroid function in these neonates is warranted. Future studies should examine the association between hypothyroidism and neurocognitive function in this population.

Phosphodiesterase Inhibitor-Based Vasodilation Improves Oxygen Delivery and Clinical Outcomes Following Stage 1 Palliation.

BACKGROUND: Systemic vasodilation using α-receptor blockade has been shown to decrease the incidence of postoperative cardiac arrest following stage 1 palliation (S1P), primarily when utilizing the modified Blalock-Taussig shunt. We studied the effects of a protocol in which milrinone was primarily used to lower systemic vascular resistance (SVR) following S1P using the right ventricular to pulmonary artery shunt, measuring its effects on oxygen delivery (DO2) profiles and clinical outcomes. We also correlated Fick-based assessments of DO2 with commonly used surrogate measures. METHODS AND RESULTS: Neonates undergoing S1P were treated according to best clinical judgment prior to (n=32) and following (n=24) implementation of a protocol that guided operative, anesthetic, and postoperative management, particularly as it related to SVR. A majority of the subjects (n=51) received a modified right ventricular to pulmonary artery shunt. In a subset of these patients (n=21), oxygen consumption (VO2) was measured and used to calculate SVR, DO2, and oxygen debt. Neonates treated with the protocol had significantly lower SVR (P=0.02), serum lactate (P<0.001), and Sa-vO2 difference (P<0.001) and a lower incidence of CPR requiring extracorporeal membrane oxygenation (E-CPR, P=0.02) within the first 72 postoperative hours. DO2 was closely associated with SVR (r2=0.78) but correlated poorly with arterial (SaO2) and venous (SvO2) oxyhemoglobin concentrations, the Sa-vO2 difference, and blood pressure. CONCLUSIONS: A vasodilator protocol utilizing milrinone following S1P effectively decreased SVR, improved serum lactate, and decreased postoperative cardiac arrest. DO2 correlated more closely with SVR than with Sa-vO2 difference, highlighting the importance of measuring VO2 in this population. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02184169.

Factors Associated With Mortality in Neonates Requiring Extracorporeal Membrane Oxygenation for Cardiac Indications: Analysis of the Extracorporeal Life Support Organization Registry Data.

OBJECTIVES: Survival among neonates supported with extracorporeal membrane oxygenation for cardiac indications is 39%. Previous single-center studies have identified factors associated with mortality, but a comprehensive multivariate analysis is not available for this population. Understanding factors associated with mortality may help design treatment strategies, determine optimal timing for cannulation, and inform patient selection. This study identifies factors associated with mortality in neonates supported with extracorporeal membrane oxygenation for cardiac indications. DESIGN: Retrospective cohort study. SETTING: Two hundred and thirty U.S. and international centers reporting extracorporeal membrane oxygenation data to the Extracorporeal Life Support Organization. SUBJECTS: Four thousand and four seventy one neonates with congenital and acquired cardiac disease supported with extracorporeal membrane oxygenation for cardiac indications during 2001-2011. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The primary outcome measure was mortality prior to hospital discharge. Overall hospital mortality was 59%. Demographic and preextracorporeal membrane oxygenation factors associated with mortality were evaluated in a multivariable model. Factors associated with death prior to hospital discharge included lower body weight, earlier era, single ventricle physiology, lower preextracorporeal membrane oxygenation arterial pH, and longer time from intubation to extracorporeal membrane oxygenation cannulation. Lower pH was associated with increased mortality regardless of cardiac diagnosis and surgical complexity. The majority of survivors separated from extracorporeal membrane oxygenation less than 8 days after extracorporeal membrane oxygenation deployment. CONCLUSIONS: Mortality for neonates supported with extracorporeal membrane oxygenation for cardiac indications is high. Severity of preextracorporeal membrane oxygenation acidosis was independently associated with increased risk of mortality. Earlier initiation of extracorporeal membrane oxygenation may reduce the degree and duration of acidosis and may improve survival. Further studies are needed to determine optimal timing of cannulation in this population.

Training fellows and residents in paediatric cardiac critical care.

As pediatric cardiac critical care becomes more sub-specialized it is reasonable to assume that dedicated units may provide a better infrastructure for improved multidisciplinary care, cardiac-specific patient safety initiatives, and dedicated training of fellows and residents. The knowledge base required to optimally manage pediatric patients with critical cardiac disease has evolved sufficiently to consider a standardized training curriculum and board certification for pediatric cardiac critical care. This strategy would potentially provide consistency of training and healthcare and improve quality of care and patient safety.

A Review of Systemic Vasodilators in Low Cardiac Output Syndrome Following Pediatric Cardiac Surgery.

Following surgery for congenital heart disease, patients develop a predictable and progressive decline in cardiac output known as low cardiac output syndrome. During low cardiac output states, a compensatory response to increase systemic perfusion occurs both innately and as part of the postoperative pharmacologic support strategies intended to increase or sustain adequate oxygen delivery. The result typically involves a rise in systemic vascular resistance and heart rate. These and other responses may actually limit the ability of the recently operated heart to provide sufficient cardiac output to meet the oxygen demands of the body. In order to improve systemic oxygen delivery, clinicians have increasingly employed systemic vasodilator therapy to reduce afterload and improve ventriculoarterial coupling. This review will summarize currently utilized pharmacologic agents that promote systemic vasodilation and improve cardiac output through afterload reduction. This article addresses the fourth of eight topics comprising the special issue entitled "Pharmacologic strategies with afterload reduction in low cardiac output syndrome after pediatric cardiac surgery".

Theoretical and Evidence-Based Benefit of Afterload Reduction in the Postoperative Pediatric Heart.

Rational use of vasodilators to induce afterload reduction is predicated on a thorough knowledge of the constituents of afterload and of the role ventriculoarterial coupling plays in determining their effects. Afterload reduction therapy should be goal directed with the intent to improve stroke volume and tissue oxygen delivery rather than to decrease blood pressure per se. This review will summarize the components comprising circulatory system afterload and will use ventriculoarterial coupling concepts to demonstrate the variable but predictable effects of vasodilator therapy on hemodynamics and tissue oxygen delivery. This article addresses the third of eight topics comprising the special issue entitled "Pharmacologic strategies with afterload reduction in low cardiac output syndrome after pediatric cardiac surgery".

Extracorporeal membrane oxygenation for the support of adults with acute myocarditis.

OBJECTIVES: To characterize survival outcomes for adult patients with acute myocarditis supported with extracorporeal membrane oxygenation and identify risk factors for in-hospital mortality. DESIGN: Retrospective review of Extracorporeal Life Support Organization registry database. SETTING: Data reported to Extracorporeal Life Support Organization by 230 extracorporeal membrane oxygenation centers. PATIENTS: Patients 16 years old or older supported with extracorporeal membrane oxygenation for myocarditis during 1995 to 2011. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: There were 150 separate runs of extracorporeal membrane oxygenation for 147 patients with a diagnosis of acute myocarditis in the Extracorporeal Life Support Organization database from 1995 through 2011. Survival to hospital discharge was 61%. Nine patients underwent heart transplantation, and transplant-free survival to discharge was 56%. Extracorporeal membrane oxygenation was deployed during extracorporeal cardiopulmonary resuscitation in 31 patients (21% of the cohort). In a multivariate model evaluating pre-extracorporeal membrane oxygenation and extracorporeal membrane oxygenation support factors, pre-extracorporeal membrane oxygenation arrest (adjusted odds ratio, 2.4; 95% CI, 1.1-5.0) and need for higher extracorporeal membrane oxygenation flows at 4 hours post-extracorporeal membrane oxygenation cannulation (odds ratio, 2.8; 95% CI, 1.1-7.3) were associated with increased odds of in-hospital mortality. In a second multivariate model evaluating adverse events while on extracorporeal membrane oxygenation, central nervous system injury (odds ratio, 26.5; 95% CI, 7.3-96.6), renal failure (odds ratio, 3.6; 95% CI, 1.4-9.3), arrhythmia (odds ratio, 5.8; 95% CI, 2.2-15.1), and hyperbilirubinemia (odds ratio, 9.1; 95% CI, 2.6-31.8) were associated with increased odds of in-hospital mortality. CONCLUSIONS: Extracorporeal membrane oxygenation can be used effectively in adults with myocarditis to support the circulation while awaiting myocardial recovery. Early extracorporeal membrane oxygenation deployment prior to cardiac arrest may be associated with better outcomes.

Next generation patient monitor powered by in-silico physiology.

The goal of this paper is to introduce a next generation patient monitoring technology that relies on objective and continuous data analytics to alleviate the data overload in the critical care unit. The technology provides the foundation for increasing the consistency and efficacy of data use in clinical practice and improving outcomes. This paper presents results for applying the approach to the hemodynamic monitoring of infants immediately following cardiac surgery and demonstrates its efficacy of estimating the probability of inadequate systemic oxygen delivery, which is an essential risk attribute in the management of critically ill patients.

Extracorporeal membrane oxygenation-supported cardiopulmonary resuscitation following stage 1 palliation for hypoplastic left heart syndrome.

OBJECTIVES: To report on survival from a large multicenter cohort of neonates with hypoplastic left heart syndrome requiring extracorporeal membrane oxygenation-assisted cardiopulmonary resuscitation after stage 1 palliation operation. DESIGN: Retrospective analysis of data from the Extracorporeal Life Support Organization data registry (1998 through 2013). We computed the survival to hospital discharge for neonates (age < 30 d) who required extracorporeal membrane oxygenation after stage 1 palliation and evaluated factors associated with mortality using multivariate logistic regression analysis. SETTING: Multicenter data reported to Extracorporeal Life Support Organization registry. PATIENTS: Infants with hypoplastic left heart syndrome after stage 1 palliation who received extracorporeal membrane oxygenation-assisted cardiopulmonary resuscitation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: There were 307 extracorporeal membrane oxygenation runs in the setting of extracorporeal membrane oxygenation-assisted cardiopulmonary resuscitation in 293 neonates with hypoplastic left heart syndrome following stage 1 palliation operation. The median age at cannulation was 9 days (interquartile range, 5-14 d). Survival to hospital discharge was 36%. In univariate analysis, gestational age, weight, extracorporeal membrane oxygenation duration, presence of air embolism, hemorrhagic complications, renal failure, and pulmonary complications (pulmonary hemorrhage and pneumothorax) were all associated with nonsurvival. In multivariate analysis, lower body weight at cannulation (odds ratio, 3.9; 95% CI, 1.9-8.3), duration of the extracorporeal membrane oxygenation (odds ratio, 3.4; 95% CI, 1.9-7.3), and renal failure while on extracorporeal membrane oxygenation (odds ratio, 2; 95% CI, 1.2-3.5) increased odds of mortality. CONCLUSIONS: Mortality for neonates with hypoplastic left heart syndrome supported with extracorporeal membrane oxygenation-assisted cardiopulmonary resuscitation after stage 1 palliation is high. Lower body weight, increased duration of extracorporeal membrane oxygenation support, and renal failure increased mortality.

Extracorporeal membrane oxygenation after stage 1 palliation for hypoplastic left heart syndrome.

OBJECTIVE: To report the outcomes from a large multicenter cohort of neonates requiring extracorporeal membrane oxygenation (ECMO) after stage 1 palliation for hypoplastic left heart syndrome. METHODS: Using data from the Extracorporeal Life Support Organization (2000-2009), we computed the survival to hospital discharge for neonates (age ≤30 days) supported with ECMO after stage 1 palliation for hypoplastic left heart syndrome. The factors associated with mortality were evaluated using multivariate logistic regression analysis. RESULTS: Among 738 neonates, the survival rate was 31%. The median age at cannulation was 7 days (interquartile range, 4-11). Black race (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.2-3.6), mechanical ventilation before ECMO (>15-131 hours: OR, 1.6; 95% CI, 1.1-2.4; >131 hours: OR, 1.9; 95% CI, 1.3-2.9), use of positive end expiratory pressure (>6-8 cm H(2)O: OR, 1.7; 95% CI, 1.1-2.7; >8 cm H(2)O: OR, 1.9; 95% CI, 1.2-3.1), and longer ECMO duration (per day, OR, 1.2; 95% CI, 1.1-1.3) increased mortality. ECMO support for failure to wean from cardiopulmonary bypass (OR, 1.6; 95% CI, 1.02-2.4) also decreased survival. ECMO complications, including renal failure (OR, 1.9; 95% CI, 1.2-3.1), inotrope requirement (OR, 1.5; 95% CI, 1.1-2.1), myocardial stun (OR, 3.2; 95% CI, 1.3-7.7), metabolic acidosis (OR, 2.9; 95% CI, 1.3-6.7), and neurologic injury (OR, 1.7; 95% CI, 1.1-2.6), during support also increased mortality. CONCLUSIONS: Mortality for neonates with hypoplastic left heart syndrome supported with ECMO after stage 1 palliation is high. Longer ventilation before cannulation, longer support duration, and ECMO complications increased mortality.

Femoral artery catheterization in neonates and infants.

OBJECTIVE: To determine the incidence of perfusion-related complications associated with indwelling femoral artery monitoring catheters in neonates and infants following introduction of a 2.5-F diameter, 5-cm length, polyethylene catheter (Cook Medical, Bloomington, IN) to our unit. DESIGN: Prospective observational cohort study. SETTING: Pediatric cardiac intensive care unit in a university-affiliated children's hospital. PATIENTS: All patients <2 yrs old with an indwelling femoral artery catheter during a 3-yr period. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Two hundred eighty-two patients (including 98 neonates), median (range) age 10 wks (0.1-84), weight 4.1 kg (2.0-11.1) were enrolled; outcomes in 249 were evaluable. Pulse strength in dorsalis pedis arteries and pulse discrepancies between feet were assessed hourly by the cardiac intensive care unit nurse and recorded on a flow sheet. Nonpalpable pulses were assessed as "absent" or "present" with ultrasonic Doppler. Following removal of the catheter, assessments of pulse strength continued until resolution of any discrepancies. Median (range) duration of catheterization was 4 days (1-23). Catheters of 2.5-F diameter were used in 227 patients and larger catheters in 55 patients. The incidence of pulse strength discrepancies between feet was 20%, loss of pulse was 3.4% (6.7% in neonates, 1.4% in older infants) when extracorporeal membrane oxygenation patients were excluded, and resolution of pulse discrepancy or loss was 100%. Duration of catheterization and use of a catheter larger than 2.5 Fr were significant predictors of loss of pulse. CONCLUSIONS: Loss of pedal pulse distal to small-bore monitoring femoral artery catheters in neonates and infants is directly related to the duration of catheterization and is less frequent when 2.5-F, 5-cm polyethylene catheters are used instead of larger catheters.