Warming Prior to Heel Stick: Blood Sample Quality and Infant Comfort-A Randomized Controlled Trial

BACKGROUND

Capillary blood sampling (heel stick) in infants is commonly performed in neonatal care units. Before the procedure, warming the infant's heel is often a customary practice, but no consensus exists on the most effective heel-warming method.

PURPOSE

To compare the effects of routinely used warming methods (glove, gel pack, or blanket) applied prior to heel stick on blood sample quality and infant's comfort.

METHODS

This prospective, double-blind, randomized controlled trial conducted in the neonatal intensive care unit included infants (postmenstrual age of ≥28 + 0 weeks and ≤43 + 6 weeks) who were computer-randomized to 1 of 3 warming methods.The primary outcome was blood flow velocity at sampling. Secondary outcomes were hemolysis index, infant COMFORTneo score, and frequency of postprocedure skin injuries. In addition, irrespective of the warming method used, the correlation between heel skin temperature and postprocedure heel skin injury was analyzed.

RESULTS

A total of 176 heel warmings were successfully randomized, and 173 were analyzed. Despite a significant difference in obtained heel skin temperature after warming between the 3 warming methods ( P = .001), no difference in blood flow velocity ( P = .91), hemolysis index ( P = .99), or COMFORTneo score ( P = .76) was found. Baseline skin temperatures above 37.0°C were associated with higher incidences of skin injury, and skin temperatures after warming were significantly higher in skin-injured heels ( P = .038).

IMPLICATIONS FOR PRACTICE AND RESEARCH

All 3 warming methods had similar effects on blood sample quality and infant's comfort. However, excessive warming of the heel should be avoided to prevent skin injuries.

Jet-Induced Blood Release From Human Fingertips: A Single-Blind, Randomized, Crossover Trial

BACKGROUND

Lancet pricks are often poorly received by individuals with diabetes; jet injection may allow lancet-free blood sampling. We examine whether the technique of jet injection can release sufficient blood from the fingertip to enable measurement of blood glucose concentration. In addition, we assess the effect of jet shape and cross-sectional area on fluid release, blood dilution, and perceived pain.

METHODS

A randomized, single-blind, crossover study was conducted on 20 healthy volunteers who received interventions on four fingertips: a lancet prick, and jet injection of a small quantity of saline solution through three differently shaped and sized nozzles. Released fluid volume, blood concentration, and glucose concentration were assessed immediately after the intervention. Pain perception and duration, and any skin reactions, were evaluated both immediately and 24 hours after the intervention.

RESULTS

Jet injection released sufficient blood from the fingertip to conduct a glucose measurement. A slot-shaped nozzle released the most blood, although less than a lancet, with slightly higher pain. The blood glucose levels estimated from the extracted fluid showed a mean absolute percentage error of 25%. There was no consistent evidence that a jet injection leads to different skin reactions at the intervention site relative to a lancet prick.

CONCLUSIONS

Fingertip penetration by jet injection can release a volume of fluid sufficient for blood glucose measurement. Jet injection with a slot-shaped nozzle and/or a nozzle with larger outlet area helps to release more fluid. This technique may enable blood sampling, glucose concentration measurement, and insulin delivery to be performed in a single device.

Capillary blood sampling increases the risk of preanalytical errors in pediatric hospital care: Observational clinical study

PURPOSE

The blood sampling procedure is complex and prone to failure, as reflected by preanalytical errors in pediatric hospital care. The primary aim was to evaluate if the risk of preanalytical errors was higher with capillary blood sampling than with venous blood sampling, and secondary, explore specific factors associated with preanalytical errors, both overall and stratified by capillary and venous blood sampling.

DESIGN AND METHODS

This observational pediatric hospital study collected outcomes from medical records and blood sampling surveys from year 2014 to 2016. The risk of preanalytical errors was analyzed with adjusted-odds ratio (adj-OR) by multivariable logistic regression with 95% confidence intervals (CIs).

RESULTS

Overall, 128 (13%) preanalytical errors were identified among 951 blood samples. The proportion and adj-OR of errors was significantly higher in capillary compared with venous blood samples, 72 (20%) of 354 versus 56 (9.4%) of 597, p = .001, adj-OR 2.88 (CI 1.79-4.64). Blood collection with multiple sample tubes was significantly associated with increased risk of preanalytical errors (n = 97 of 601, 16%), while log weight (kg) significantly decreased the risk of preanalytical errors adj-OR 0.66 (CI 0.50-0.86), indicating a protective effect of increasing weight. However, stratified analyses indicated a protective effect of increasing log weight for venous blood sampling adj-OR 0.52 (CI 0.38-0.72), but not capillary blood sampling, adj-OR 1.08 (CI 0.76-1.55).

CONCLUSION

This study indicates that capillary blood sampling collection increases the risk of preanalytical errors. Further, a child's increasing body weight reduced the risk of preanalytical errors, while multiple sample tube collections significantly increased the risk of preanalytical errors.

PRACTICE IMPLICATIONS

This new information may help nurses improve their knowledge concerning blood sampling collection in pediatrics. Altogether, this study also indicates that implementing more venous blood sampling and improve the cases of capillary sampling could reduce the number of preanalytical errors in pediatric hospitals.

Comparison between a laser lancing device and lancet for capillary blood sampling, capillary blood hemoglobin measurement, and blood typing

BACKGROUND

Blood donor screening includes tests using capillary blood, which is usually obtained by finger pricking using a lancet; however, the lancet has some shortcomings, such as skin puncture pain and needle stick injury. Recently, laser lancing devices for finger-prick sampling have been developed. We compared capillary blood Hb (cHb) levels and blood typing results obtained using a laser lancing device with those obtained using a lancet.

STUDY DESIGN AND METHODS

cHb levels, blood typing results, and skin puncture pain scores were assessed in 191 participants. Finger-prick sampling was performed using LMT-1000 (LaMeditech, Seoul, Korea) and a lancet on the same finger on different hands. Paired venous Hb (vHb) levels were assessed in 103 participants using an automated hematology analyzer and compared with the cHb levels obtained using both lancing devices.

RESULTS

The paired cHb results obtained with the laser lancing device and lancet showed a strong correlation (r = 0.927, p < .001) without any significant difference (p = .113) and a substantial agreement (κ = 0.654) for the identification of participants with a low Hb level (<12.5 g/dl). cHb levels were significantly higher than vHb levels with both lancing devices (mean differences: 0.27-0.43 g/dl). The results of blood typing using the laser lancing device showed 100% accuracy. Use of the laser lancing device showed significantly lower skin puncture pain scores (p < .001).

CONCLUSION

Use of a laser lancing device for capillary Hb measurement and blood typing showed accurate results, with significantly reduced skin puncture pain. Laser lancing devices could be feasible for donor screening tests.