Underwent Norwood Operation Research Articles

Neighborhood socioeconomic status and length of stay after congenital heart disease surgery.

Socioeconomic factors are associated with health outcomes and can affect postoperative length of stay after congenital heart disease (CHD) surgery. The hypothesis of this study is that patients from neighborhoods with a disadvantaged socioeconomic status (SES) have a prolonged length of hospital stay after CHD surgery. Pre- and postoperative data were collected on patients who underwent CHD surgery at the University of Maryland Medical Center between 2011 and 2019. A neighborhood SES score was calculated for each patient using data from the United States Census Bureau and patients were grouped by high vs. low SES neighborhoods. The difference of patient length of stay (LOS) from the Society for Thoracic Surgeons median LOS for that surgery was the primary outcome measure. Linear regression was performed to examine the association between the difference from the median LOS and SES, as well as other third variables. The difference from the median LOS was -4.8 vs. -2.2 days in high vs. low SES groups (p = 0.003). SES category was a significant predictor of LOS in unadjusted and adjusted regression analyses. There was a significant interaction between Norwood operation and SES-patients with a low neighborhood SES who underwent Norwood operation had a longer LOS, but there was no difference in LOS by SES in patients who underwent other operations. Neighborhood SES is a significant predictor of the LOS after congenital heart disease surgery. This effect was seen primarily in patients undergoing Norwood operation.

Attributable mortality benefit of digoxin treatment in hypoplastic left heart syndrome after the Norwood operation: An instrumental variable-based analysis using data from the Pediatric Health Information Systems Database

BackgroundObservational studies have demonstrated an association between the use of digoxin and reduced interstage mortality after Norwood operation for hypoplastic left heart syndrome (HLHS). Digoxin use has increased significantly but remains variable between different hospitals, independent of case-mix. Instrumental variable analyses have the potential to overcome unmeasured confounding, the major limitation of previous observational studies and to generate an estimate of the attributable benefit of treatment with digoxin. MethodsA cohort of neonates with HLHS born from January 1, 2007 to December 31, 2021 who underwent Norwood operation at Pediatric Health Information Systems Database hospitals and survived >14 days after operation were studied. Using hospital-specific, 6-month likelihood of administering digoxin as an instrumental variable, analyses adjusting for both unmeasured confounding (using the instrumental variable) and measured confounders with multivariable logistic regression were performed. ResultsThe study population included 5,148 subjects treated at 47 hospitals of which 63% were male and 46% non-Hispanic white. Of these, 44% (n = 2,184) were prescribed digoxin. Treatment with digoxin was associated with superior 1-year transplant-free survival in unadjusted analyses (85% vs 82%, P = .02). This survival benefit persisted in an instrumental-variable analysis (OR: 0.71, 95% CI: 0.54-0.94, P = .01), which can be converted to an absolute risk reduction of 5% (number needed to treat of 20). ConclusionsIn this observational study of patients with HLHS after Norwood using instrumental variable techniques, a significant benefit in 1-year transplant-free survival attributable to digoxin was demonstrated. In the absence of clinical trial data, this should encourage the use of digoxin in this vulnerable population.

Periscopic technique in Norwood operation is associated with better preservation of early ventricular function.

ObjectiveAlthough the right ventricle (RV) to pulmonary artery conduit in stage 1 Norwood operation results in improved interstage survival, the long-term effects of the ventriculotomy used in the traditional technique remain a concern. The periscopic technique (PT) of RV to pulmonary artery conduit placement has been described as an alternative technique to minimize RV injury. A retrospective study was performed to compare the effects of traditional technique and PT on ventricular function following Norwood operation.MethodsA retrospective study of all patients who underwent Norwood operation from 2012 to 2019 was performed. Patients with baseline RV dysfunction and significant tricuspid valve regurgitation were excluded. Prestage 2 echocardiograms were reviewed by a blinded experienced imager for quantification of RV function (sinus and infundibular RV fractional area change) as well as for regional conduit site wall dysfunction (normal or abnormal, including hypokinesia, akinesia, or dyskinesia). Wilcoxon rank-sum tests were used to assess differences in RV infundibular and RV sinus ejection fraction and the Fisher exact test was used to assess differences in regional wall dysfunction.ResultsTwenty-two patients met inclusion criteria. Eight underwent traditional technique and 14 underwent PT. Median infundibular RV fractional area change was 49% and 37% (P = .02) and sinus RV fractional area change was 50% and 41% for PT and traditional technique (P = .007) respectively. Similarly qualitative regional RV wall function was better preserved in PT (P = .002).ConclusionsThe PT for RV to pulmonary artery conduit in Norwood operation results in better preservation of early RV global and regional systolic function. Whether or not this benefit translates to improved clinical outcome still needs to be studied.

Trends in Discharge Prescription of Digoxin After Norwood Operation: An Analysis of Data from the Pediatric Health Information System(PHIS) Database.

Quality improvement efforts have focused on reducing interstage mortality for infants with hypoplastic left heart syndrome (HLHS). In 1/2016, two publications reported that use of digoxin was associated with reduced interstage mortality. The degree to which these findings have affected real world practice has not been evaluated. The discharge medications of neonates with HLHS undergoing Norwood operation between 1/2007 and 12/2018 at Pediatric Health Information Systems Database hospitals were studied. Mixed effects models were calculated to evaluate the hypothesis that the likelihood of digoxin prescription increased after 1/2016, adjusting for measurable confounders with furosemide and aspirin prescription measured as falsification tests. Interhospital practice variation was measured using the median odds ratio. Over the study period, 6091 subjects from 45 hospitals were included. After adjusting for measurable covariates, discharge after 1/2016 was associated with increased odds of receiving digoxin (OR 3.9, p < 0.001). No association was seen between date of discharge and furosemide (p = 0.26) or aspirin (p = 0.12). Prior to 1/2016, the likelihood of receiving digoxin was decreasing (OR 0.9 per year, p < 0.001), while after 1/2016 the rate has increased (OR 1.4 per year, p < 0.001). However, there remains significant interhospital variation in the likelihood of receiving digoxin even after adjusting for known confounders (median odds ratio = 3.5, p < 0.0001). Following publication of studies describing an association between digoxin and improved interstage survival, the likelihood of receiving digoxin at discharge increased without similar changes for furosemide or aspirin. Despite concerted efforts to standardize interstage care, interhospital variation in pharmacotherapy in this vulnerable population persists.

Standardization of the Perioperative Management for Neonates Undergoing the Norwood Operation for Hypoplastic Left Heart Syndrome and Related Heart Defects.

In-hospital complications after the Norwood operation for single ventricle heart defects account for the majority of morbidity and mortality. Inpatient care variation occurs within and across centers. This multidisciplinary quality improvement project standardized perioperative management in a large referral center. Quality improvement project. High volume cardiac center, tertiary care children's hospital. Neonates undergoing Norwood operation. The quality improvement team developed and implemented a clinical guideline (preoperative admission to 48 hr after surgery). The composite process metric, Guideline Adherence Score, contained 13 recommendations in the guideline that reflected consistent care for all patients. One-hundred two consecutive neonates who underwent Norwood operation (January 1, 2013, to July 12, 2016) before guideline implementation were compared with 50 consecutive neonates after guideline implementation (July 13, 2016, to May 4, 2018). No preguideline operations met the goal Guideline Adherence Score. In the first 6 months after guideline implementation, 10 of 12 operations achieved goal Guideline Adherence Score and continued through implementation, reaching 100% for the last 10 operations. Statistical process control analysis demonstrated less variability and decreased hours of postoperative mechanical ventilation and cardiac ICU length of stay during implementation. There were no statistically significant differences in major hospital complications or in 30-day mortality. A higher percentage of patients were extubated by postoperative day 2 after guideline implementation (67% [30/47] vs 41% [41/99], respectively; p = 0.01). Of these patients, reintubation within 72 hours of extubation significantly decreased after guideline implementation (0% [0/30] vs 17% [7/41] patients, respectively; p = 0.02). This initiative successfully implemented a standardized perioperative care guideline for neonates undergoing the Norwood operation at a large center. Positive statistical process control centerline shifts in Guideline Adherence Score, length of postoperative mechanical ventilation, and cardiac ICU length of stay were demonstrated. A higher percentage were successfully extubated by postoperative day 2. Establishment of standard processes can lead to best practices to decrease major adverse events.

Association of a Home Monitoring Program With Interstage and Stage 2 Outcomes.

BackgroundIn shunt‐dependent, single‐ventricle patients, mortality remains high in the interstage period between discharge after neonatal surgery and stage 2 operation. We sought to evaluate the impact of our infant single‐ventricle management and monitoring program (ISVMP) on interstage mortality and stage 2 outcomes.Methods and ResultsThis retrospective single‐center cohort study compared patients enrolled in ISVMP at hospital discharge with historical controls. The relationship of ISVMP to interstage mortality was determined with a bivariate probit model for the joint modeling of both groups, using an instrumental variables approach. We included 166 ISVMP participants (December 1, 2010, to June 30, 2015) and 168 controls (January 1, 2007, to November 30, 2010). The groups did not differ by anatomy, gender, race, or genetic syndrome. Mortality was lower in the ISVMP group (5.4%) versus controls (13%). An ISVMP infant compared with a historical control had an average 29% lower predicted probability of interstage death (adjusted probability: −0.29; 95% CI, −0.52 to −0.057; P=0.015). On stratified analysis, mortality was lower in the hypoplastic left heart syndrome subgroup undergoing Norwood operation (4/84 [4.8%] versus 12/90 [14%], P=0.03) but not in those with initial palliation of shunt only (P=0.90). ISVMP participants were younger at the time of the stage 2 operation (138 versus 160 days, P<0.001), with no difference in postoperative mortality or length of stay.ConclusionsIn this single‐center study, we report significantly lower interstage mortality for participants with hypoplastic left heart syndrome enrolled in ISVMP. Younger age at stage 2 operation was not associated with postoperative mortality or longer length of stay.

Impact of Regional Cerebral Perfusion on Outcomes Among Neonates Undergoing Norwood Operation.

To evaluate the impact of regional cerebral perfusion (RCP) during heart operation on outcomes in neonates undergoing Norwood operation. We performed a retrospective cohort study using data from the Single Ventricle Reconstruction trial data set. The adjusted effect of RCP use on each outcome was studied using a penalized logistic regression model with bootstrap validation. Of 549 patients included in the study, 252 patients (45.9%) received RCP during their heart operation. In univariate comparisons, the majority of the baseline characteristics and preoperative risk factors were similar in the RCP and No RCP group. The total cardiopulmonary bypass (CPB) time and the total cross-clamp (CC) time were longer in the RCP group (RCP vs No RCP, median CPB time: 161 minutes vs 109 minutes; median CC time: 63 minutes vs 43 minutes). In adjusted models, the use of RCP was not associated with decreased mortality and/or need for heart transplant at hospital discharge (odds ratio [OR]: 0.73; 95% confidence interval [CI]: 0.43-1.25) or prolonged mechanical ventilation (OR: 1.20, 95% CI: 0.62-2.28) or prolonged hospital length of stay (OR: 1.30, 95% CI: 0.73-2.30). We demonstrated that use of RCP was associated with longer CPB times, increased use of ultrafiltration, and higher probability of open chest after Norwood operation. This study did not demonstrate any impact of RCP on in-hospital mortality and/or heart transplantation, prolonged mechanical ventilation, and prolonged hospital length of stay among neonates undergoing Norwood operation.

Impact of Hybrid Stage 1 Palliation for Hypoplastic Left Heart Syndrome: Histopathological Findings

The purpose of the study is to analyze the impact of hybrid stage 1 palliation on right ventricular myocardial pathology in hypoplastic left heart syndrome. Sufficient amount of right ventricular biopsies could be obtained from 16 of 32 patients who underwent Norwood operation between 2007 and 2013. Histopathological findings of right ventricle in patients who underwent primary Norwood operation (primary group, n = 5), patients with aortic atresia (HS1P AA group, n = 6) or aortic stenosis (HS1P AS group, n = 5) who underwent staged Norwood palliation following hybrid stage 1 palliation were compared. To eliminate the influence of right ventricular pressure afterload, right ventricular biopsies were obtained from patients with truncus arteriosus communis (TAC group, n = 6) at total correction. The percentage of myocardial fibrosis was significantly higher in both HS1P groups than in TAC group; moreover, it was significantly higher in HS1P AA group than in primary group. Capillary vascular density was significantly lower in all hypoplastic left heart syndrome groups than in TAC group. At the sub-endocardial layer, collagen type I/III ratios were higher in HS1P AA group than in other hypoplastic left heart syndrome groups. The proportions of N-cadherin immunolocalized to myocyte termini were lower in all hypoplastic left heart syndrome groups than in TAC group. Right ventricle in hypoplastic left heart syndrome showed more significant ischemic change and myocardial immaturity than that in truncus arteriosus communis. Hybrid stage 1 palliation for aortic atresia would be a risk factor for further right ventricular myocardial ischemia.

Post-cardiotomy Rescue Extracorporeal Cardiopulmonary Resuscitation in Neonates with Single Ventricle After Intractable Cardiac Arrest: Attrition After Hospital Discharge and Predictors of Outcome

Extracorporeal cardiopulmonary resuscitation (ECPR) in children with cardiac arrest refractory to conventional cardiopulmonary resuscitation (CPR) has been reported with encouraging results. We reviewed outcomes of neonates with functional single ventricle (FSV) surviving post-cardiotomy ECPR after hospital discharge. Fifty-eight patients who required post-cardiotomy extracorporeal membrane oxygenation (ECMO) since the introduction of our ECPR protocol (January 2007-December 2011) were identified. Forty-one were neonates. Survival analysis was conducted. Of 41 neonates receiving post-cardiotomy ECMO, 32 had FSV. Twenty-one had ECPR. Fourteen underwent Norwood operation (NO) for hypoplastic left heart syndrome (HLHS). Seven had non-HLHS FSV. Four (of 7) underwent modified NO/DKS with systemic-to-pulmonary shunt (SPS), 2 SPS only and 1 SPS with anomalous pulmonary venous connection repair. Mean age was 6.8±2.1days. ECMO median duration was 7days [interquartile range (IQR25-75: 4-18)]. Survival to ECMO discontinuation was 72% (15 of 21 patients) and at hospital discharge 62% (13 of 21 patients). The most common cause of late attrition was cardiac. At last follow-up (median: 22months; IQR25-75: 3-36), 47% of patients were alive. Duration of ECMO and failure of lactate clearance within 24h from ECMO deployment determined late survival after hospital discharge (p<0.05). Rescue post-cardiotomy ECMO support in neonates with FSV carries significant late attrition. ECMO duration and failure in lactate clearance after deployment are associated with unfavorable outcome. Emphasis on CPR quality, refinement of management directives early during ECMO and aggressive early identification of patients requiring heart transplantation might improve late survival.

Association of Hematocrit and Red Blood Cell Transfusion with Outcomes in Infants Undergoing Norwood Operation.

The objective of this study was to investigate the association between red blood cell (RBC) transfusion and hematocrit values with outcomes in infants undergoing Norwood operation. This study included infants ≤2 months of age who underwent Norwood operation with either a modified Blalock-Taussig shunt or a right ventricle-pulmonary artery shunt. Demographics, preoperative, operative, daily laboratory data, and postoperative variables were collected. The primary outcome measures evaluated included mortality, ICU length of stay, length of mechanical ventilation, and days to chest closure. The secondary outcome measures evaluated included lactate levels, estimated glomerular filtration rate, and inotrope score in the first 14 days after heart operation. Cox proportional hazard models were fitted to study the probability of study outcomes as a function of hematocrit values and RBC transfusions after operation. Eighty-nine patients qualified for inclusion. With a median hematocrit of 46 (IQR 44, 49), and a median RBC transfusion of 92 ml/kg (IQR 31, 384) in the first 14 days after operation, 81 (91 %) patients received RBC transfusions. A multivariable analysis adjusted for risk factors, including the age, weight, prematurity, cardiopulmonary bypass and cross-clamp time, and postoperative need for nitric oxide and dialysis, demonstrated no association between hematocrit and RBC transfusion with majority of study outcomes. This single-center study found that higher hematocrit values and increasing RBC transfusions are not associated with improved outcomes in infants undergoing Norwood operation.

One size does not fit all: the influence of age at surgery on outcomes following Norwood operation.

BackgroundGiven our large catchment area that often results in later presentation age, we sought to understand our institutional outcomes for the Norwood operation in the context of published data. Specifically, we studied whether operative and late death post-Norwood are dependent on age at operation.MethodsRetrospective review of 105 consecutive infants undergoing Norwood (2004–2011) at our institution. Patients were divided into those undergoing Norwood ≤ 7 days of age (N = 43; 41%) and those undergoing Norwood > 7 days of age (N = 63; 59%). Operative mortality (≥30 days), interstage mortality (between Norwood and superior bidirectional Glenn), STS-mortality (operative death + in-hospital death), and late mortality, occurring any time following hospital discharge were compared among groups. Multivariable factors for mortality at each time-point were compared using logistic regression models.ResultsUnderlying diagnosis was HLHS in 67 (64%) with the remainder (N = 38; 36%) being other single ventricle variants. Median age at surgery was 8 days (range 1–63 days) and mean weight at surgery was 3.2 ± 0.6 kg. Pulmonary blood flow was provided by a right ventricle-pulmonary artery conduit in 94% (N = 99). Overall operative survival was 92%, with 73% (N = 66) undergoing bidirectional Glenn. Median age was higher for operative survivors compared to non-survivors (12 days vs. 5 days; P = 0.036), with operative mortality higher for infants ≤7 days at Norwood compared to infants >7 days at Norwood (14% vs. 3%; P = 0.04). After censoring for in-hospital death, age ≤ 7 days was also associated with increased risk for late death (26% vs. 5%; P = 0.005).ConclusionsIn contrast to other institutional series, infants at our center undergoing Norwood operation at an earlier age have worse outcomes. Adoption of published practice patterns could lead to different local outcomes because of intangible center-specific effects, underscoring the principle that results from one institution may not be generalizable to others. Targeted center-specific internal review, if possible, should precede externally recommended changes in practice.

Safe use of alteplase in a 10 months old infant with cardio-embolic stroke

The knowledge about safety and efficacy of thrombolysis in paediatric stroke is limited, especially for very young children. We present an infant with cardioembolic stroke treated with alteplase. He had hypoplastic left heart syndrome since birth. He underwent Norwood operation, followed by bidirectional cavopulmonary anastomosis at 3 months. On aspirin therapy he was well until heart failure developed at the age of 9 months with 2 thrombi in the right ventricle. During the course of enoxaparin therapy sudden acute left-sided haemiplegia occurred. The emergency brain CT scan was normal. Informed consent was obtained from parents after explaining the alteplase treatment protocol and possible complications. Alteplase was administered i.v. according to standard adult stroke regimen. A control CT scan obtained 24 h later was negative for intracranial haemorrhage but the hypodense area in insula, internal capsule and subcortical area of the right parietal region were indicative of ischaemic stroke. Anticoagulation therapy was continued. He recovered hand functions after 5 days and full repertoire of movements on his left side 3 weeks later. A neurological examination performed 2 months after indicated mild residual haemiparesis and a modified Rankin scale score of 1. Three months later, the patient died of progressive heart failure. An international multicentre prospective trial is ongoing to investigate the safety and appropriate dose of alteplase for paediatric ages 2–17 years. The aim of this paper is to report safe use of alteplase even in a very young child.

A Single-Center Experience of Extubation Failure in Infants Undergoing the Norwood Operation

Identify incidence, etiology, and predictors of extubation failure in neonates and infants who underwent Norwood operation with either a modified Blalock-Taussig shunt (mBTS) or a Sano shunt at a single tertiary care, academic children's hospital. Extubation failure for our study was defined as reintubation within 96 hours after extubation. We collected demographics, preoperative, intraoperative, postoperative, and peri-extubation data in a retrospective, observational format in patients who underwent Norwood operation with either a modified Blalock-Taussig shunt (mBTS) or a Sano shunt between January 2005 and March 2011. Clinical outcomes evaluated included the success or failure of extubation, cardiac intensive care unit (CICU) length of stay (LOS), hospital LOS, and mortality. Descriptive, univariate, and multivariate statistics were utilized to compare groups with extubation failure and extubation success. Of 64 eligible patients during the study period, extubation failure occurred in 22% (14 of 64) of the patients. Eight patients failed extubation in the first 24 hours with an extubation failure rate of 12%. The median age of patients was 18 days (range 13.75 days to 22 days) and median weight of patients was 3.37 kg (range 3.11 kg to 3.86 kg). Twelve patients received a mBTS while 52 patients received a Sano shunt. All extubation failures occurred in patients receiving a Sano shunt. The most common risk factors for failed extubation were lung disease in 29% (4 of 14), cardiac dysfunction in 21% (3 of 14), diaphragmatic paralysis in 14% (2 of 14), airway edema in 14% (2 of 14), vocal cord paralysis in 14% (2 of 14), and laryngotracheomalacia in 7% (1 of 14). Patients with extubation failure had longer CICU LOS and hospital LOS. Overall mortality at the time of hospital discharge was 8%. Independent predictors of extubation failure included use of nitric oxide after surgery, increased days of mechanical ventilation prior to extubation, elevated inotrope score leaving the operating room, and presence of atelectasis prior to extubation. Extubation failure in children after the Norwood operation is a slow and evolving process occurring as late as 96 hours after extubation and is not associated with an increase in in-hospital mortality. Causes of failed extubation are diverse. Successful weaning from positive pressure ventilation depends on adequate cardiovascular function, the presence of satisfactory ventilatory reserves, and favorable pulmonary mechanics.

Post-cardiotomy extracorporeal cardiopulmonary resuscitation in neonates with complex single ventricle: analysis of outcomes

Extracorporeal cardiopulmonary resuscitation (ECPR) in children with cardiac arrest refractory to conventional cardiopulmonary resuscitation (CPR) has been reported with encouraging results. We sought to review outcomes of neonates with functional single ventricle (FSV) receiving post-cardiotomy ECPR. Forty-eight patients who required post-cardiotomy extracorporeal membrane oxygenation (ECMO) since the introduction of our ECPR protocol (January 2007-December 2009) were identified. Twenty-seven were neonates. Review of records and survival analysis were conducted. Of 27 neonates receiving post-cardiotomy ECMO 20 had FSV. Fourteen had ECPR. Ten underwent Norwood operation (NO) for hypoplastic left heart syndrome (HLHS). Four had FSV other than HLHS. Three underwent Damus-Kay-Stansel or modified NO with systemic-to-pulmonary shunt (SPS) and one SPS with anomalous pulmonary venous connection repair. Mean age and weight were 7.8 ± 2.9 days and 3.44 ± 1.78 kg, respectively. ECMO median duration was 6 days (interquartile range (IQR) 3-14). Survival to ECMO discontinuation was 79% (11 of 14 patients) and at hospital discharge was 57% (8 of 14 patients). The most common cause of death was multi-organ failure (four of six deaths). At last follow-up (median: 11 months (1-34)) 43% of patients were alive. CPR mean duration for patients with favorable versus unfavorable outcome was 38.6 ± 6.3 versus 42.1 ± 7.7 min (p = 0.12). Previously reported determinants for poorer prognosis in conventional non-rescue ECMO (such as pre-ECMO pH<7.2, renal, neurological or pulmonary hemorrhage complications, and pre- and post-vasoactive inotropic score) did not influence outcome between survivors and non-survivors (p>0.05). ECMO support in neonates with FSV requiring ECPR can result in favorable outcome in more than half of patients at hospital discharge. Aggressive strategy toward timely application of ECPR is justified. Expeditious ECPR deployment after proper patients' selection, refinement of CPR quality and use of adjunctive neuroprotective interventions, such as induced hypothermia, might further improve outcomes.

Aortic Arch Recoarctation after the Norwood Stage I Palliation: The Comparative Accuracy of Blood Pressure Cuff and Echocardiographic Doppler Gradients in Detecting Significant Obstruction

Aortic arch recoarctation is responsible for significant morbidity and mortality after the Norwood Stage I procedure. Cuff blood pressure (BP) gradients and echocardiographic Doppler gradients are routinely used as noninvasive screening tests for early detection, but accuracy has not been systematically tested. We sought to evaluate the ability of cuff BP and Doppler gradients, measured at routine outpatient clinic visits, to predict significant arch obstruction in single ventricle patients after the Norwood operation. Consecutive patients who underwent Norwood operation at our institution were identified retrospectively. Cuff and echocardiographic gradients measured prior to the pre-Glenn catheterization were compared to peak-to-peak systolic neoaortic arch gradients obtained at catheterization. Statistical analyses, including Receiver Operator Characteristic (ROC) curves, were performed using different cutpoints for cuff and echocardiographic gradients, evaluating their ability to predict a clinically significant catheter gradient. Data were obtained in 68 patients. Echocardiographic gradient cutpoints were more sensitive but less specific than cuff BP gradient cutpoints at detecting a catheter gradient > or = 10 mm Hg. Echo gradients > or = 20 mm Hg showed 85% sensitivity and 95% specificity in detecting a systolic catheter gradient > or = 10 mm Hg. chocardiographic Doppler outperforms cuff BP as a sensitive noninvasive screening tool for early detection of significant arch obstruction in infants after the Norwood operation.

Does size matter? Larger Blalock–Taussig shunt in the modified Norwood operation correlates with better hemodynamics☆

Excess pulmonary to systemic blood flow ratio (Qp/Qs) correlates with hemodynamic instability and mortality after modified Norwood operation. Studies suggest that maximal oxygen delivery occurs at a Qp/Qs of around 1. The use of a rather small modified Blalock-Taussig shunt (MBTS) is believed to achieve this goal. However, optimal MBTS size with respect to postoperative hemodynamics remains unclear. Between 2/2002 and 2/2004, 20 consecutive patients underwent Norwood operation; there were 19 operative survivors: nine with a normalized MBTS area (NSA) > or = 3.3 mm2/kg (group 1) and 10 with NSA < 3.3 mm2/kg (group 2). Mean arterial pressure (MAP) and common atrial pressures (CAP), arterial and superior vena cava oxygen saturations, urinary output and inotropes recorded for the postoperative hours 0, 6, 12, 18, 24 and 48 were analyzed. Hospital mortality was 11.1% (1/9) in group 1 and 30% (3/10) in group 2 (P = 0.6). For group 1 significantly higher MAP of 52+/-1.3 versus 46+/-0.8 mmHg (P < 0.001), higher urinary output of 6.2+/-0.5 versus 4.2+/-0.5 ml/kg per h (P < 0.01), lower CAP of 8+/-0.3 versus 10+/-0.4 mmHg (P < 0.001), and lower heart rate of 145+/-2.6 versus 160+/-1.6 bpm were recorded than for group 2. In group 1, lower doses of adrenaline (0.03+/-0.01 versus 0.15+/-0.01 microg/kg per min, P < 0.05) and noradrenaline (0.01+/-0.01 versus 0.13+/-0.04 microg/kg per min, P < 0.01) were needed. Although Qp/Qs was more often calculated to be > 1.5 in group 1 (51 versus 31%), arteriovenous oxygen difference and oxygen excess factor were not significantly different, indicating similar oxygen delivery. Monitoring of the central venous oxygen saturations and application of afterload reduction in cases of high Qp/Qs allows the insertion of a larger MBTS without association with lower oxygen delivery. In fact, better hemodynamic status with less inotropic support was noted with a larger MBTS early after Norwood operation.