Establishing reference ranges of cord blood: point-of-care hemostatic function assessment in preterm and term neonates.

BACKGROUND: Thrombelastometry, allowing timely assessment of global hemostatic function, is increasingly used to guide hemostatic interventions in bleeding patients. Reference values are available for adults and children, including infants but not neonates immediately after birth. METHODS: Neonates were grouped as preterm (30 + 0 to 36 + 6 weeks/days) and term (37 + 0 to 39 + 6 weeks/days). Blood samples were drawn from the umbilical cord immediately after cesarean section and analyzed by thrombelastometry. Reference ranges were determined for the extrinsic and intrinsic coagulation pathways, fibrin polymerization, and hyperfibrinolysis detection. RESULTS: All extrinsically activated test parameters, but maximum lysis (P = 0.139) differed significantly between both groups (P ≤ 0.001). Maximum clot firmness in the fibrin polymerization test was comparable (P = 0.141). All intrinsically activated test parameters other than coagulation time (P = 0.537) and maximum lysis (P = 0.888) differed significantly (P < 0.001), and so did all aprotinin-related test parameters (P ≤ 0.001) but maximum lysis (P = 0.851). CONCLUSIONS: This is the first study to identify reference ranges for thrombelastometry in preterm and term neonates immediately after birth. We also report differences in clot initiation and clot strength in neonates born <37 versus ≤40 weeks of gestation, mirroring developmental hemostasis. IMPACT: Impact: This prospective observational study is the first to present reference ranges in preterm and term infants for all types of commercially available tests of thrombelastometry, notably also including the fibrin polymerization test. IMPORTANCE: Viscoelastic coagulation assays such as thrombelastometry have become integral to the management of perioperative bleeding by present-day standards. Reference values are available for adults, children, and infants but not for neonates. Key message: Clot initiation and formation was faster and clot strength higher in the term than in the preterm group. Parameters of thrombelastometry obtained from cord blood do not apply interchangeably to preterm and term neonates.

Comparison of hematologic indices and markers of infection in umbilical cord and neonatal blood.

OBJECTIVE: Evaluation of a neonate for suspected early neonatal sepsis routinely includes blood tests such as complete blood count, C-reactive protein (CRP) and culture. In order to obviate the need for venepuncture, we prospectively compared these tests in paired samples from umbilical cord and peripheral venous blood drawn during the first hours after birth in both preterm and term infants. METHODS: Paired blood samples were studied from asymptomatic neonates with risk factors for early sepsis. Data were collected on maternal and neonatal factors that may have influenced the correlation between the tests. RESULTS: Three hundred fifty pairs of samples were studied. Significant correlation between umbilical cord and peripheral venous samples was found for white blood cell (WBC; r = 0.683) and platelets (PLT) (r = 0.54). Correlation for hemoglobin was lower (r = 0.36). No cases of early neonatal sepsis were detected. However, contamination rates were 12% in umbilical cord blood and 2.5% in peripheral venous blood cultures. WBC rose after birth and the 90th percentile rose from 22 500 in umbilical cord blood to 29 700 in peripheral blood. CONCLUSIONS: Screening for sepsis with umbilical cord CBC may be useful provided normal ranges are adjusted accordingly.

Predictive value of the respiratory syncytial virus risk-scoring tool in the term infant in Canada.

BACKGROUND: Palivizumab prophylaxis against respiratory syncytial virus (RSV) infection has been widely adopted for high-risk infants during the RSV season, based on country-specific guidelines. OBJECTIVE: To determine if a validated, risk-scoring tool (RST), can be applied to term, RSV-positive infants seen in the emergency room (ER) to predict need for hospitalization, in order to target prophylaxis cost effectively at a selected group of children. DESIGN: Retrospective, descriptive study. SETTING: McMaster Children's Hospital in Hamilton, Ontario, Canada. PARTICIPANTS: A total of 72, consecutive, term, RSV-positive cases were identified retrospectively, from November through April during the 2006-2007 RSV season. METHODS: A questionnaire/chart review was conducted on 68 of 72 cases, to determine risk categories based on the RST. Four, trained abstractors, extracted pertinent data from the medical records of RSV-positive patients. Means, standard deviations (SD), and percents were used to describe the study variables for hospitalized and ER patients discharged home. Chi-square tests were used to compare infants' risk factors to hospitalization. ANOVA was used for comparisons within and between risk groups and RST scores. A p-value of <0.05 was considered statistically significant. RESULTS: The majority of infants scored in the low-risk category (n = 44), versus moderate (n = 16) or high risk (n = 8). Within the low-risk category, 27 (61%) of children were admitted to hospital compared to 17 (39%) who were treated in the ER and discharged home. The mean RST scores for those admitted to the pediatric intensive care unit/ward, the ward only, or those discharged home from the ER were 48.3 (n = 10), 41.0 (n = 36), and 36.5 (n = 22), respectively (p = 0.17). The mean number of risk factors for those discharged home versus hospitalized patients was 2.5 (1.3) and 2.97 (1.13), respectively (p = 0.15). Only two of eight cases in the high-risk group required intensive care. CONCLUSIONS: Overall, the risk-scoring tool did not discriminate between low versus moderate- to high-risk RSV-positive term infants who require hospitalization which has cost implications, since universal prophylaxis of this cohort would be financially prohibitive. A larger study is necessary to establish risk factors that more accurately determine RSV hospitalization among term infants.

Umbilical cord blood nutrients in low birth weight babies in relation to birth weight & gestational age.

BACKGROUND & OBJECTIVE: Low birth weight (LBW) babies are a vulnerable group and represent two outcomes--preterm birth (preterm LBW) and term with intrauterine growth retardation (term LBW). LBW babies are considered to have low nutrient reserve, but the extent of deficiency as compared to the normal babies and the differences between preterm LBW and term LBW are unclear. This study was carried out to look at key anthropometric, biochemical and clinical (ABC) parameters of LBW babies, both preterm and term, in comparison to a control group of term normal weight babies. METHODS: A group of 500 babies was selected at birth from a tertiary care teaching hospital and categorized into LBW (n = 251) with preterm LBW (n = 59), term LBW (n = 192) and term controls (n = 249). Two controls were dropped as tests could not be performed in the available cord blood sample. Key anthropometric and biochemical parameters were measured. Socio-economic status, age, parity, height and pre-delivery haemoglobin of the mothers were also recorded. RESULTS: The maternal characteristics were comparable in the three groups. Socio-economically, majority of them belonged to lower middle or upper lower class (Class III and IV) representing the non affluent. All the anthropometric measurements and nutrients measured namely total protein, albumin, cholesterol, triglycerides, calcium, magnesium, zinc and iron were significantly lower in LBW babies compared to term control babies. These values were lowest in preterm LBW followed by term LBW. Total iron binding capacity (TIBC) showed inverse association with iron. Some of the babies including control babies had protein, albumin, calcium and iron below the normal range and mean albumin, calcium and iron levels were below the normal range in all the three subsets. INTERPRETATION & CONCLUSION: Preterm and term LBW babies are born with significantly lower nutrient reserves at birth compared to term control babies. Normal weight babies from the non affluent sections also have low nutrients especially albumin, calcium and iron. As these levels are liable to be further lowered by recurrent infections and inappropriate feeding habits, nutritional surveillance, extra feeding and supplements like calcium and iron are recommended for such vulnerable babies to promote optimum growth and to prevent deficiencies. This is important as currently, there are no clear or uniform recommendations for extra feeding and nutrient supplements to LBW babies and no supplements other than exclusive breast feeding are recommended for term normal birth weight babies. Extra nutritional inputs for LBW and selected non affluent babies along with care of the prospective and prenatal mothers for ensuring adequate transfer of nutrients to the offspring seem necessary. Such interventions can be integrated with the existing health care programmes to reach all the beneficiaries.