A comparative study of heel-stick devices for infant blood collection

Effects of automatic heel lancet on invasiveness in neonates: A systematic review and meta-analysis

AIM

We conducted a meta-analysis comparing the invasiveness of automatic lancet devices, which can collect adequate amount of blood at shallow puncture depths, with conventional manual lance devices (lancet or needle) to statistically identify less invasive instruments for neonatal heel lance.

METHODS

We searched PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL, and Ichushi databases for studies comparing the invasiveness between automatic lancet and manual lancet or needle in term and preterm neonates in neonatal intensive care unit.

RESULTS

This review included 9 out of 449 searched articles, with 673 neonates. Automatic lancet had significantly lower pain scores (standardised mean difference: -2.0, 95% confidence interval: -3.3 to -0.7), heart rate (mean difference: -8.0, 95% confidence interval: -13.8 to -2.1), cry duration (mean difference: -21.5, 95% confidence interval: -32.5 to -10.4), number of punctures (mean difference: -0.6, 95% confidence interval: -1.1 to -0.2), and duration of procedures (mean difference: -37.7, 95% confidence interval: -75.2 to -0.2) than manual lancet or needle. Furthermore, peripheral oxygen saturation was significantly higher in automatic lancet than in manual lancet or needle (mean difference: 4.5, 95% confidence interval: 0.5-8.5).

CONCLUSION

Automatic heel lancet devices were less invasive than manual heel lance devices (lancet or needle).

Accounting for arterial and capillary blood gases for calculation of cerebral blood flow in preterm infants

One of the most feared neurological complications of premature birth is intraventricular hemorrhage, frequently triggered by fluctuations in cerebral blood flow (CBF). Although several techniques for CBF measurement have been developed, they are not part of clinical routine in neonatal intensive care. A promising tool for monitoring of CBF is its numerical assessment using standard clinical parameters such as mean arterial pressure, carbon dioxide partial pressure (pCO₂) and oxygen partial pressure (pO₂). A standard blood gas analysis is performed on arterial blood. In neonates, capillary blood is widely used for analysis of blood gas parameters. The purpose of this study was the assessment of differences between arterial and capillary analysis of blood gases and adjustment of the mathematical model for CBF calculation to capillary values. The statistical analysis of pCO₂ and pO₂ values collected from 254 preterm infants with a gestational age of 23-30 weeks revealed no significant differences between arterial and capillary pCO₂ and significantly lower values for capillary pO₂. The estimated mean differences between arterial and capillary pO₂ of 15.15 mmHg (2.02 kPa) resulted in a significantly higher CBF calculated for capillary pO₂ compared to CBF calculated for arterial pO₂. Two methods for correction of capillary pO₂ were proposed and compared, one based on the mean difference and another one based on a regression model.

CONCLUSION

Capillary blood gas analysis with correction for pO₂ as proposed in the present work is an acceptable alternative to arterial sampling for the assessment of CBF.

WHAT IS KNOWN

• Arterial blood analysis is the gold standard in clinical practice. However, capillary blood is widely used for estimating blood gas parameters. • There is no significant difference between the arterial and capillary pCO₂ values, but the capillary pO₂ differs significantly from the arterial one.

WHAT IS NEW

• The lower capillary pO₂ values yield significantly higher values of calculated CBF compared to CBF computed from arterial pO₂ measurements. • Two correction methods for the adjustment of capillary pO₂ to arterial pO₂ that made the difference in the calculated CBF insignificant have been proposed.

Capillary blood reference intervals for platelet parameters in healthy full-term neonates in China

Background

No consensus has been reached on capillary blood reference intervals for platelet parameters in full-term neonates. We aimed to establish neonatal capillary blood reference intervals for platelet parameters and evaluate influences of sex, gestational age and postnatal age on platelet parameters.

Methods

This study was a prospective investigation and implemented in 594 healthy full-term neonates from 12 to 84 h of age, using SYSMEX XN-9000 haematology automatic analyser by means of capillary blood. Reference intervals for platelet parameters were defined by an interval of 2.5th − 97.5th percentiles.

Results

Capillary reference interval for platelet count was (152–464) × 10⁹/L. No significance was found between sex-divided reference intervals for platelet parameters. The values of platelet count changed minimally across gestational age (37–41 weeks) and postnatal age (12–84 h). Reference intervals for other platelet parameters were affected by these factors to a different extent.

Conclusions

We established capillary blood reference intervals for platelet parameters in the first days after birth of full-term neonates in China.

Issues in neonatal cellular analysis

Hematologic values in neonates differ significantly from those in older children and adults. Quantitative and qualitative differences are present as a reflection of the developmental changes during fetal hematopoiesis and, so, correlate with gestational age. At birth, the hemoglobin, mean corpuscular volume, and WBC counts of term newborns are significantly higher than those of older children and adults, and in preterm neonates the differences are even more pronounced. This review explores these differences and the major factors that account for them from the hematology laboratory standpoint. After a discussion of the developmental hematopoiesis and normal hematologic values in term and preterm neonates, important preanalytic factors, such as limited blood availability, effect of sampling site, and violent crying, and analytic interferences are examined. Finally, the review addresses resulting challenges in interpretation of hematologic test results in term and preterm neonates, especially issues surrounding neonatal reference intervals and critical value reporting, and suggests possible solutions.

An automatic incision device for obtaining blood samples from the heels of preterm infants causes less damage than a conventional manual lancet

OBJECTIVES

To evaluate in a randomised blind study the effect on puncture site lesions of two different incision devices used to obtain blood samples from preterm infants by repeated heel sticks.

SETTING

The neonatal intensive care unit at the Hospital for Children and Adolescents and Laboratory, Helsinki University Central Hospital.

PATIENTS

A total of 100 preterm infants (birth weight below 2500 g) not previously subjected to heel stick sampling.

INTERVENTIONS

The infants were randomly allocated to blood sampling from the heel with either a conventional manual lancet or an automatic incision device. The same type of lancet was used for any given baby throughout the study (2-21 days).

MAIN OUTCOME MEASURES

The damage caused by sampling was evaluated using four criteria: bruising of the heel, inflammation of the heel, bruising of either the ankle or the leg, and skin healing at the puncture site. The evaluation was based on photographs presenting typical categories of each outcome.

RESULTS

To obtain a sufficient volume of blood, on average 2.6 times more punctures were needed when the conventional manual lancet was used than when the automatic incision device was used. Heels punctured with the lancet had more bruising (100% v 84%) and more signs of inflammation (79% v 53%), and there was more bruising of the ankle or leg (92% v 53%) than when the automatic incision device was used. Skin healed equally rapidly in the two groups.

CONCLUSION

The use of an automatic incision device for collecting repeated skin puncture samples from preterm infants is less traumatic than the use of a conventional manual lancet.