Dominique Bettex

Cardiac output measurement in children: comparison of the Ultrasound Cardiac Output Monitor with thermodilution cardiac output measurement.

ObjectiveTo compare the assessment of cardiac output (CO) in children using the noninvasive Ultrasound Cardiac Output Monitor (USCOM) with the invasive pulmonary artery catheter (PAC) thermodilution cardiac output measurement.Design and settingProspective observational study in axa0tertiary center for pediatric cardiology of axa0university childrens hospital.PatientsTwenty-four pediatric patients with congenital heart disease without shunt undergoing cardiac catheterization under general anesthesia.Measurements and resultsCO was measured by USCOM using axa0suprasternal CO Doppler probe in children undergoing cardiac catheterization. USCOM data were compared to CO simultaneously measured by PAC thermodilution technique. Measurements were repeated three times within 5u202fmin in each patient. Axa0mean percentage error not exceeding 30% was defined as indicating clinical useful reliability of the USCOM. CO values measured by PAC ranged from 1.3 to 5.3u202fl/min (median 3.6u202fl/min). Bias and precision were −0.13 and 1.34u202fl/min, respectively. The mean percentage error of CO measurement by the USCOM compared to PAC thermodilution technique was 36.4% for USCOM.ConclusionsOur preliminary data demonstrate that cardiac output measurement in children using the USCOM does not reliably represent absolute CO values as compared to PAC thermodilution. Further studies must evaluate the impact of incorporating effective aortic valve diameters on CO measurement using the USCOM.

Risk Factor Analysis of 170 Single-Institutional Contegra Implantations in Pulmonary Position

BACKGROUNDnThe aim of this study is to evaluate risk factors affecting survival of Contegra grafts used in the pulmonary position.nnnMETHODSnOne hundred seventy Contegra implanted (2001 to 2007) in the pulmonary position for replacement after a prior repair (90), Ross procedure (29), tetralogy of Fallot and variants (22), truncus arteriosus (13), Rastelli procedure (8), and miscellaneous (8) were reviewed. Median age was 107 (0.1 to 894) months. Follow-up was 96% complete with a median duration of 65 (7 to 98) months.nnnRESULTSnThere were 7 early and 6 late deaths (none Contegra related) with a survival of 92%±2% at 98 months. Thirty-four Contegra were replaced at a median duration of 43 (7 to 82) months. Eight of 28 balloon-dilated Contegra remain palliated at 49 (23 to 73) months. Multivariate analysis showed Contegra less than 16 mm (p<0.001; HR [hazard ratio] 0.07), high pulmonary pressure (p<0.001; HR 4), and prior operation era (p=0.006; HR 0.3) as independent risk factors for Contegra replacement. The freedom from replacement for Contegra less than 16 mm and 16 mm or greater were 48%±8% and 98%±2%; for presence and absence of high pulmonary pressure were 52%±11% and 88%±3% and for era 1 and 2 were 77%±5% and 88%±4% at 60 months, respectively. Twenty-three of 123 surviving Contegra have a mean Doppler gradient greater than 20 mm Hg. Contegra less than 16 mm, smaller age group, obstructive arborization, and era 1 were significantly associated with higher gradients. While 18 (15%) surviving Contegra have moderate or more regurgitation, 88 (72%) have no significant gradient or regurgitation.nnnCONCLUSIONSnContegra grafts integrate well into the body. Larger Contegra show predictable function with a survival approaching homografts over medium term. Better case selection as one ascends the learning curve tends to improve survival. With easy availability and predictable quality, Contegra grafts continue to be a promising complement to homografts.

Mid-term results of right axillary incision for the repair of a wide range of congenital cardiac defects

OBJECTIVEnWe evaluated the mid-term results of the right axillary incision used for the repair of various congenital heart defects.nnnMETHODSnAll the patients who were operated with this incision between March 2001 and December 2007 were reviewed. There were 123 patients (median age 4.7 {0.4-19.4} years and median weight 16.6 {3.8-62} kg) undergoing atrial septal defect (ASD) closure (62), repair of partial anomalous pulmonary venous connection (PAPVC) (22), correction of partial atrioventricular septal defect (AVSD) (19), and restrictive perimembranous ventricular septal defect (VSD) (20). Additional procedures involved tricuspid valve plasty (10), mitral annuloplasty (3), reduction plasty of the aortic sinus (2), resuspension of the aortic valve cusp (2), sub aortic membrane resection (1), or reimplantation of Scimitar vein (1). The surgical technique involved peripheral (groin) and central (SVC+/-aorta) cannulation for institution of cardiopulmonary bypass. Fibrillatory arrest was used for repair of ASDs and cardioplegic arrest for repairs involving the atrioventricular valves as well as VSDs. The median CPB and aortic clamp times were 72 (35-232) and 0 (0-126) min, respectively.nnnRESULTSnThere was no need for conversion to another approach in any patient. Early morbidity included transient paresis of left upper arm (1), stenting of SVC after repair of a sinus venosus defect (1) and revision for bleeding (1). Follow-up echo showed no residual defect in 116 patients and minor residual defects in 7 patients: tiny ASD (2), tiny VSD (1) and mitral regurgitation (4). One patient developed stenosis in the right external iliac artery used for cannulation, necessitating surgical intervention. All the patients are in excellent condition after a median follow-up of 4.1 (0.4-7.1) years. The incision healed well and the thorax and the breast showed no deformity on follow-up.nnnCONCLUSIONSnThe right axillary incision provides a quality of repair for various congenital defects similar to that obtained by using standard surgical approaches. Because of its deceitful location, and the camouflaging effect of being hidden by the resting arm, it has superior cosmetic appeal compared to conventional incisions. The incision does not interfere with subsequent development of the thorax or the breast (in case of females).

Measurement of Activated Coagulation Time in Children: Evaluation of the Blood-Saving Kaolin i-STAT Activated Coagulation Time Technique in Pediatric Cardiac Anesthesia

OBJECTIVEnTo compare the activated coagulation times (ACTs) measured with the blood-saving kaolin i-STAT 1 ACT technique (Abbott Point of Care Inc, Princeton, NJ) with ACTs obtained from the widely used ACTR II device (Medtronic, Inc, Minneapolis, MN) in children undergoing cardiac surgery.nnnDESIGNnA prospective, observational single-center study.nnnPARTICIPANTSnForty-four pediatric cardiac surgery patients.nnnINTERVENTIONnSurgery was performed with cardiopulmonary bypass (CPB) necessitating heparinization.nnnMETHODS AND MAIN RESULTSnACTs measured on the i-STAT 1 device (2 × 95 μL) were compared with those obtained from the Medtronic ACTR II device (2 × 0.5 mL). Blood samples were drawn before, during, and after heparinization for CPB and paired for statistical analysis. The 2 techniques were compared using simple and multiregression analyses and the Bland-Altman method. In total, 179 intrarater and 142 interrater data pairs were analyzed. The intrarater reliability of the 2 devices was good, with a mean bias and limits of agreement of +2.0 and -55.5/+59.5 seconds for the Medtronic ACTR II and +0.5 and -59.9/+60.9 seconds for the i-STAT 1. An interrater reliability analysis of the mean of simultaneously measured ACT of the Medtronic ACTR II and both i-STAT 1 devices yielded a mean bias of -5.3 seconds and limits of agreement of -210.1/+199.5 seconds. A comparison of the higher of the paired ACT values from both devices showed similar results. After the removal of heparin, the i-STAT 1s ACT values became significantly lower than those measured on the Medtronic ACTR II (p < 0.001). Simple and multiregression analyses revealed that base excess independently influenced the mean bias of the ACT values from the Medtronic ACTR II (p = 0.037) and i-STAT 1 devices (p = 0.036).nnnCONCLUSIONnThe kaolin i-STAT 1 ACT technique agreed well with the Medtronic ACTR II technique during the nonheparinized phase that preceded CPB. The overall agreement between the ACT obtained from the 2 devices was poor. The routine use of i-STAT 1 measured ACT values cannot be recommended as a reliable alternative to the Medtronic ACTR II.

Role of sevoflurane in organ protection during cardiac surgery in children: a randomized controlled trial.

OBJECTIVESnThe protective effects of volatile anaesthetics against ischaemia-reperfusion injury have been shown in vitro, but clinical studies have yielded variable results. We hypothesized that, in children, sevoflurane provides superior cardioprotection after cardiac surgery on cardiopulmonary bypass (CPB) compared with totally intravenous anaesthesia (TIVA).nnnMETHODSnIn this randomized controlled, single-centre study, 60 children with cyanotic and acyanotic heart defects undergoing elective cardiac surgery under CPB (RACHS-1 1-3) were randomized to sevoflurane or TIVA (midazolam <6 months of age, propofol >6 months of age). The primary end-point was the postoperative peak cardiac troponin I/T (cTnI/T). Perioperative cardiac function (as determined by brain-type natriuretic peptide, echocardiography and postoperative vasopressor/inotrope requirements), short-term clinical outcomes (duration of intubation, intensive care unit and hospital length of stay), postoperative inflammatory profile, and pulmonary, renal and liver function were defined as secondary end-points. Analysis of variance was used for statistical analysis.nnnRESULTSnThere was no statistically significant difference in postoperative peak troponin values or any of the secondary end-points. In the subgroup of acyanotic patients under 6 months, sevoflurane led to significantly lower postoperative troponin levels compared with midazolam [reduction of 54% (95% confidence interval 29-71%, P = 0.002)], without any differences in secondary outcome parameters.nnnCONCLUSIONSnSevoflurane did not provide superior myocardial protection in our general paediatric cardiac surgical population. In children under 6 months, however, sevoflurane might be beneficial in comparison with midazolam. The conditioning effects of sevoflurane in specific paediatric subgroups need to be further investigated.

Impact of cytokine release on ventricular function after hepatic reperfusion: a prospective observational echocardiographic study with tissue Doppler imaging

BackgroundPostreperfusion syndrome and haemodynamic instability are predictors for poor outcome after liver transplantation. Cytokine release has been claimed to be responsible for postreperfusion syndrome. However, the underlying pathophysiologic mechanism is not clarified.The aim of this prospective observational study was to correlate cardiac performance (measured by transoesophageal echocardiography (TEE), Doppler and Tissue Doppler Imaging (TDI)) to plasmatic cytokines: IL-6, IL-8, CXCL1, TGF-β and CD40L at 5 different time points during liver transplantation.MethodsSeventeen consecutive patients scheduled for orthotopic liver transplantation, age 18 to 75 years without contraindication for transoesophageal echocardiography were included. Patients were monitored with TEE and TDI.Systolic and diastolic cardiac function, MAP, MPAP, CVP, PCWP, CO and blood samples for cytokine assays were recorded or collected after induction, 15 min after vena cava inferior clamping, 2 to 5 min after reperfusion, 60 min after reperfusion and at the end of surgery.ResultsMean arterial pressure and catecholamine requirements remained unchanged, MPAP, CVP and CO increased, SVR decreased after unclamping. Postreperfusion syndrome did not develop. The haemodynamic parameters and the variations of TEE parameters were consistent with the volume load changes during clamping and declamping and did not reveal systolic or diastolic cardiac dysfunction. All cytokines, except TGF-β, increased.ConclusionThese findings suggest, that significant cytokine release during liver transplantation is not necessarily coincident with haemodynamic instability and impaired cardiac function.Trial registrationClinicalTrials.gov: NCT00547924

Successful Lung Transplant After Prolonged Extracorporeal Membrane Oxygenation (ECMO) in a Child With Pulmonary Hypertension: A Case Report

Introduction: The use of extracorporeal membrane oxygenation (ECMO) is considered a risk factor for, or even a potential con- traindication to, lung transplantation. However, only a few pediatric cases have been described thus far. Case Presentation: A 9-year-old boy with idiopathic pulmonary arterial hypertension developed cardiac arrest after the insertion of a central catheter. ECMO was used as a bridge to lung transplantation. However, after prolonged resuscitation, he developed medullary ischemia and medullary syndrome. After 6 weeks of ECMO and triple combination therapy for pulmonary hypertension, including continuous intravenous prostacyclin, he was weaned off support, and after 2 weeks, bilateral lung transplantation was performed. At 4 years post-transplant, he has minimal problems. The medullary syndrome has also alleviated. He is now back to school and can walk with aids. Conclusions: Increasing evidence supports the use of ECMO as a bridge to LT, reporting good outcomes. In the modern era of PAH therapy, it is feasible to use prolonged ECMO support as a bridge to lung transplant, with the aim of weaning off this support; however, its use requires more experience and knowledge of long-term outcomes.

Insuffisance cardiaque droite aiguë. 2ème partie

Apres la 1ere partie, qui a presente la physiopathologie et le diagnostic, voici maintenant les possibilites therapeutiques de l’insuffisance cardiaque droite aigue.