Assessment of cardiac output and volume load by transpulmonary thermodilution technique in immature pigs.

OBJECTIVE: To assess the accuracy of cardiac output (CO) measured by transpulmonary thermodilution technique (TPTD)and explore the validity of intrathoracic blood volume index (ITBVI) for assessment of circulatory volume status. METHODS: Ten immature pigs with a mean weight of (20.6±1.9)kg were studied during the conditions including normovolemia, hypervolemia, and hypovolemia. Simultaneous CO was measured in each condition using pulmonary artery thermodilution (PATD) method and TPTD. More specifically, CO (COPA) was determined with PATD, while CO (COTP) and ITBVI were determined with TPTD. All measurements were repeated 3 times. Central venous pressure (CVP) and heart rate were measured at the same time. The potential correlations of CVP and ITBVI with cardiac index (CI) and stroke volume index (SVI) in each blood volume status were analyzed. RESULTS: A total of 90 simultaneous measurements of COPA and COTP in 3 different blood volume conditions were made. The correlation coefficient between the two measurements was 0.977 (P<0.001) and the mean difference was (0.25±0.26)L/min (95%CI:0.20-0.30 L/min, P<0.001). The coefficient of variation of COTP was 3.7%, while COPA was 5.4%. Compared with those in normovolemia, CVP and ITBVI in hypervolemia significantly increased (P=0.002, 0.019), ITBVI in hypovolemia decreased significantly (P<0.001), and CVP in hypovolemia decreased insignificantly (P=0.05). Correlation analysis revealed a significant correlation between ITBVI with CI and SVI in normovolemia (r=0.741, P=0.014; r=0.885, P=0.001). In contrast, correlations between CVP with CI and SVI were poor. CONCLUSIONS: TPTD can accurately and precisely measure CO in different blood volume conditions. ITBVI measured by TPTD has better validity for the assessment of circulatory volume status than CVP.

Pulse oximetry with clinical assessment to screen for congenital heart disease in neonates in China: a prospective study.

BACKGROUND: Several pioneering studies have provided evidence for the introduction of universal pulse oximetry screening for critical congenital heart disease. However, whether the benefits of screening reported in studies from high-income countries would translate with similar success to low-income countries is unknown. We assessed the feasibility and reliability of pulse oximetry plus clinical assessment for detection of major congenital heart disease, especially critical congenital heart disease, in China. METHODS: We did a pilot study at three hospitals in Shanghai to assess the accuracy of pulse oximetry plus clinical assessment for detection of congenital heart disease. We made a data collection plan before recruitment. We then undertook a large, prospective, and multicentre screening study in which we screened all consecutive newborn babies (aged 6-72 h) born at 18 hospitals in China between Aug 1, 2011, and Nov 30, 2012. Newborn babies with positive screen results (either an abnormal pulse oximetry or abnormal clinical assessment) were referred for echocardiography within 24 h of screening. We identified false-negative results by clinical follow-up and parents' feedback. We calculated sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios for pulse oximetry alone, and in combination with clinical assessment, for detection of major and critical congenital heart disease. FINDINGS: In the pilot study, 6785 consecutive newborn babies were screened; 46 of 49 (94%) cases of asymptomatic major congenital heart disease and eight of eight (100%) cases of asymptomatic critical disease were detected by pulse oximetry and clinical assessment. In the prospective multicentre study, we screened 122,738 consecutive newborn babies (120,707 asymptomatic and 2031 symptomatic), and detected congenital heart disease in 1071 (157 critical and 330 major). In asymptomatic newborn babies, the sensitivity of pulse oximetry plus clinical assessment was 93·2% (95% CI 87·9-96·2) for critical congenital heart disease and 90·2% (86·4-93·0) for major disease. The addition of pulse oximetry to clinical assessment improved sensitivity for detection of critical congenital heart disease from 77·4% (95% CI 70·0-83·4) to 93·2% (87·9-96·2). The false-positive rate for detection of critical disease was 2·7% (3298 of 120,392) for clinical assessment alone and 0·3% (394 of 120,561) for pulse oximetry alone. INTERPRETATION: Pulse oximetry plus clinical assessment is feasible and reliable for the detection of major congenital heart disease in newborn babies in China. This simple and accurate combined method should be used in maternity hospitals to screen for congenital heart disease. FUNDING: Key Clinical Research Project sponsored by Ministry of Health, Shanghai Public Health Three-Year Action Plan sponsored by Shanghai Municipal Government, and National Basic Research Project of China.

Neonatal pulse oximetry screening improves detecting of critical congenital heart disease.

OBJECTIVE: Life-threatening critical congenital heart disease (cCHD) is often not detected in the neonatal period. Unrecognized cCHD results in high morbidity and mortality rates. As a non-invasive, convenient, quick and accurate measuring method, pulse oximetry is considered to be a promising strategy to screen for cCHD in neonates. This article is a review on the neonatal pulse oximetry screening for cCHD. DATA SOURCES: Articles on neonatal pulse oximetry screening for cCHD were accessed from PubMed, using keywords including congenital heart defects, neonatal screening and oximetry. STUDY SELECTION: Original articles and critical reviews selected were relevant to the review's theme. RESULTS: The factors in the course of implementation, including threshold for positive pulse-oximetry screening results, the pulse oximeters used, timing of the screening, and the measuring position, influence the accuracy of the screening. It is recommended that the screening is completed on the second day of life, before hospital discharge. Motion-tolerant pulse oximeters, which can also be applied to measure the saturation in low-perfusion conditions, should be used. The probe should be put on both the right hand and on one foot. Thresholds of < 95% in either limb or a difference of > 3% between the limbs as a positive result may be appropriate. It should be emphasized that pulse-oximetry screening cannot be used as the only way to detect cCHD, clinical examination is also important in this situation. Cost-benefit analysis in the United Kingdom revealed it was plausible to use pulse oximetry as an adjunct to clinical examination. However, it is still controversial as to whether pulse oximetry can be used as a routine screening method for cCHD in neonates. CONCLUSIONS: Neonatal pulse oximetry screening improves detection of cCHD. Further studies should be carried out before it becomes one of the routine newborn screening programs.

Prevalence of congenital heart disease at live birth: an accurate assessment by echocardiographic screening.

AIM: To determine the true prevalence of congenital heart disease (CHD) at live birth using echocardiographic screening. METHODS: A total of 5190 consecutive newborns from two secondary hospitals were included. Each neonate had a complete clinical evaluation with echocardiographic diagnosis at average 47 h of age. Newborns with persistent CHD underwent at least 4 months of follow-up, and the temporal trend of prevalence of mild CHD was assessed. RESULTS: Overall live birth prevalence of CHD was 26.6‰ (severe 3.5‰, moderate 5.4‰ and mild 17.7‰), and prevalence of CHD that could be detected by clinical evaluation was 12.1‰. The most common CHD was ventricular septal defect (VSD, 17.3‰), followed by atrial septal defect (ASD, 6.2‰), patent ductus arteriosus (PDA, 1.3‰), tetralogy of Fallot (TOF, 0.4‰), single ventricle (SV, 0.4‰), atrioventricular septal defect (AVSD, 0.2‰) and double outlet right ventricle (DORV, 0.2‰). Female predominance was observed in mild CHD (VSD, ASD), and male predominance was observed in severe CHD. The prevalence of CHD was reduced to 19.5‰ at the 4-month follow-up, which was largely caused by spontaneous closure rate of muscular VSD. CONCLUSION: Prevalence of CHD determined by echocardiography screening was higher but more accurate than that obtained from birth defect registries.