Avoiding Repeat Needle Sticks in Sick Foals

The push-pull technique is an acceptable method for obtaining blood samples for venous blood gas analysis in foals and avoids repeated needle sticks, according to a recent study.

A manual packed cell volume should be performed in place of hematocrit measurement, researchers added.

This study compared venous blood gas parameters from samples collected by a push-pull technique through a jugular catheter with those sampled by direct jugular venipuncture in 17 hospitalized foals.

Three different techniques for drawing a blood sample from a catheter were reviewed: the discard, the reinfusion, and the push-pull methods.

The push-pull technique avoided the loss of blood associated with the discard method and reduced the risk of contamination associated with the reinfusion method, they said.

A 10 mL syringe was used to aspirate a volume of blood equal to 3 times the dead space volume of a 16G catheter and extension set (total 2.4 mL). This was immediately reinfused into the vein without disconnecting the syringe. This procedure was repeated 3 times before connecting a 1 mL heparinized syringe to collect venous blood.

A 20G 1-inch needle and 1 mL syringe were used to obtain a blood sample from the contralateral jugular vein.

All samples were analyzed with an automated blood gas analyzer within 10 minutes of collection.

There was a high level of agreement between the results obtained by the 2 sampling methods at both 0 and 24 hours for almost all parameters except hematocrit and PVO2 values, the researchers found.

This method would also be appropriate for electrolytes, glucose and lactate in sick neonatal foals.

The project was funded by a research fund (RFF) of the University of Naples Federico II.

For more information:

Del Prete C, Lanci A, Cocchia N, et al. Venous blood gas parameters, electrolytes, glucose and lactate concentration in sick neonatal foals: direct venipuncture versus push-pull technique. Equine Vet J 2020 [Epub August 8]. https://doi.org/10.1111/evj.13332