Name: Tail Vein Puncture Without Anesthesia
Uploaded: 2023-06-30T14:30:00
Description: Watch this Scientific Journal Video about Tail Vein Puncture Without Anesthesia at JoVE.com

tail vein puncture without anesthesia

Estudio comparativo de las técnicas de extracción de sangre en ratas

Blood sampling is necessary for most animal studies, both in vivo and in vitro. In rats, as the frequency and amount of blood sampling can be significant, it is helpful to have different alternatives for collection. Various methods have been described in previous studies.
The most commonly used techniques are tail vein puncture and saphenous vein blood draw. Tail vein sampling is suitable for all rat strains. With proper training, the procedure is simple to perform and causes minimal distress to the animal1. Similarly, the saphenous vein blood draw, provided it is done properly, is also a quick and simple collection method. Neither method requires anesthesia, and both allow for repeated draws of small amounts of blood. However, the saphenous vein puncture usually yields a lower blood volume1 and requires the presence of two people to leave one hindlimb exposed for puncture2.
If large amounts of blood need to be collected from a single animal, cardiac puncture or puncture of the vena cava may be used (up to 10 mL of blood can be drawn from a 150 g rat with cardiac puncture2). These techniques require anesthesia and are terminal procedures. The animal must be euthanized after any of these two techniques2. The jugular stick is an alternative that can be used if large amounts of blood need to be collected in a study that has not yet reached its endpoint. However, this technique also requires significant technical skills to avoid harm to the animal; hence, its use should be limited3.
Other techniques, such as the subclavian vein blood draw, do not need the use of anesthetics before blood collection and allow for repeated sampling of small volumes of blood. However, restrained handling and appropriate needle incision are required for this technique. An improper operation may result in animal pain or even mortality, and the training for this method may be fastidious4. 
Other anecdotal procedures include the orbital puncture and the sublingual vein puncture, both of which require an anesthetic, and neither are recommended nor widely used. Though previous studies have shown faster blood collection by orbital puncture than by tail vein puncture, it was found that orbital puncture under diethyl-ether anesthesia was less well tolerated than the latter method (based on the animals' excitation scores and urine production)5. Moreover, this method is highly influenced by the skill of the person who performs the procedure and is mainly performed by experienced veterinarians. Comparably, the sublingual vein puncture is less distressing and is recommended for repeated blood sampling6. However, this technique presents severe adverse effects such as reduced food and water intake, which can lead to the animal's death7. 
This study describes two methods used in our laboratory for repeated blood sampling. Tail vein puncture can be performed on a conscious animal, and the tissue damage and adverse effects are minimal. The modification of this technique in this study includes stabilizing the tail with the index and middle finger, which allows a single operator to perform the blood collection. The dorsal penile vein puncture has already been described for simple intravenous injections. This technique is performed under anesthesia and allows for a reliable blood source in case of difficulties with other methods (e.g., during the immediate postoperative period, with a small animal, when performing perioperative blood draw under anesthesia). Similar to tail vein sampling, the injury at the puncture site will have a minor overall effect on the animal compared to the techniques mentioned above8. The aim of this methods paper is to offer inexperienced researchers simple and reliable blood sampling alternatives according to the context (e.g., for procedures done under anesthesia, for studies including male rats, for animals with thin tail veins).

Autor destacado: Métodos de recolección de sangre dependientes del contexto en ratas 

Punción modificada de la vena de la cola y la vena del pene para el muestreo de sangre en el modelo de rata

The issue of repeated blood collection methods needs to be addressed since the majority of studies on rats require them. It's important to take into account that a sampling method can be very efficient in a certain context, but become unsuitable for another study. This protocol aims to offer simple and reliable blood sampling alternatives to researchers.Both methods can be done by a single operator and require no extensive prior training, which allows for standardized procedure. When an animal is under anesthesia, the effect of isoflurane can lead to vessel spasm and make the tail vein puncture unsuitable for blood collection. Our protocol offers an alternative in this situation, the penile vein puncture, which presents a better success rate and yields significantly more amounts of blood in less time.

Watch this Scientific Journal Video about Tail Vein Puncture Without Anesthesia at JoVE.com

Tail Vein Puncture Without Anesthesia  

Punción de la vena de la cola sin anestesia

Para comenzar, asegure a la rata en un cono de restricción de plástico, encierre el extremo grande del cono alrededor de la base de la cola. Asegúrese de que el animal esté cómodo y que la respiración no esté restringida durante todo el procedimiento. Sumerja la cola en agua tibia durante aproximadamente un minuto para dilatar la vena y seque la cola con una toalla de papel.En el retenedor, coloque al animal boca abajo con la cola acostada sobre una almohadilla térmica. Para seleccionar la vena de la cola adecuada para el muestreo, gire todo el animal hacia el lado derecho o izquierdo. Utilice el tercio terminal de la cola para la punción de los vasos sanguíneos, ya que los vasos se vuelven más superficiales en esta zona.Limpie la cola con toallitas de etanol al 70% en el sitio de punción y colóquela en el borde de la almohadilla térmica, creando un ángulo en el tercio terminal de la cola. Esto lleva la vena a la superficie y crea más espacio para tomar la muestra. Para la toma de muestras de sangre, mueva el émbolo hacia adelante y hacia atrás en la jeringa varias veces para suavizar la extracción y luego tire del émbolo para crear presión negativa en la jeringa.Asegure la cola plana en la almohadilla térmica con el índice y el dedo medio no dominantes. Coloque el dedo medio proximalmente y el dedo índice distalmente con el sitio de punción entre estos dos dedos. Deslice la jeringa de insulina contra el dedo índice con el ojo de la aguja apuntando hacia arriba hasta que se inserte en la vena.Esto crea un ángulo de 35 grados entre la aguja y la cola. Una vez que la aguja ha entrado en la vena, la sangre fluirá hacia la jeringa. Extraiga lentamente el émbolo de la jeringa a una velocidad constante para recoger el volumen deseado.Retire la jeringa de la cola y permita que se forme una gota de sangre en el lado de punción de la cola. Aspire esta sangre para recoger unos microlitros más de sangre, en caso de un procedimiento no estéril. Aplique presión en el sitio de punción para detener el sangrado y limpie el área con una toallita con alcohol nueva.Después de retirar la rata del cono, devuélvala a su jaula. Las tasas de éxito con los métodos de punción de la vena de la cola se compararon con la tasa de éxito del método de punción de la vena del pene bajo anestesia. Curiosamente, bajo anestesia, la vena de la cola se volvió muy poco confiable y tuvo una tasa de éxito de solo el 25%Las tasas de éxito mostraron resultados casi similares para la punción de la vena de la cola en ratas conscientes y la punción de la vena del pene bajo anestesia.El muestreo de sangre se realizó en menos de seis minutos en la punción de la vena de la cola sin anestesia, y el método de punción de la vena del pene bajo anestesia, mientras que el método de punción de la vena de la cola bajo anestesia tomó más de ocho minutos debido a múltiples fallas.

Research

JoVE Journal

Medicine

Tail Vein Puncture Without Anesthesia

Modified Tail Vein and Penile Vein Puncture for Blood Sampling in the Rat Model

Blood samples are required in most experimental animal designs to assess various hematological parameters. This paper presents two procedures for blood collection in rats: the lateral tail vein puncture and the dorsal penile vein puncture, which offer significant advantages over other previously described techniques. This study shows that these two procedures allow for fast sampling (under 10 min) and yield sufficient blood volumes for most assays (202 &#956;L &#177; 67.7 &#956;L). The dorsal penile vein puncture must be done under anesthesia, whereas the lateral tail vein puncture can be done on a conscious, restrained animal.
Alternating these two techniques, therefore, enables blood draw in any situation. While it is always recommended for an operator to be assisted during a procedure to ensure animal welfare, these techniques require only a single operator, unlike most blood sampling methods that require two. Moreover, whereas these previously described methods (e.g., jugular stick, subclavian vein blood draw) require extensive prior training to avoid harm to or death of the animal, tail vein and dorsal penile vein puncture are rarely fatal. For all these reasons, and according to the context (e.g., for studies including male rats, during the perioperative or immediate postoperative period, for animals with thin tail veins), both techniques can be used alternately to enable repeated blood draws.

Here, we present a protocol to offer rapid, easy, and reliable blood collection alternatives for the rat model. We describe three different blood sampling methods according to the context: tail vein puncture under anesthesia or on a conscious animal, and dorsal penile vein puncture under anesthesia.

Blood samples are required in most experimental animal designs to assess various hematological parameters. This paper presents two procedures for blood ...

Investigación

Medicina

To begin, secure the rat in a plastic restraining cone, enclose the large end of the cone around the base of the tail. Ensure that the animal is comfortable and breathing is unrestricted throughout the procedure. Dip the tail in warm water for about one minute to dilate the vein, and dry the tail with a paper towel.In the restrainer, position the animal facing down with the tail lying on a heating pad. To select the appropriate tail vein for sampling, rotate the entire animal to the right or left side. Use the terminal third of the tail for blood vessel puncturing since the vessels become more superficial in this zone.Wipe the tail with 70%ethanol wipes at the puncture site and place it on the edge of the heating pad, creating an angle in the terminal third of the tail. This brings the vein to the surface and creates more space for taking the sample. For blood sampling, move the plunger back and forth in the syringe several times to smoothen the withdrawal and then pull on the plunger to create negative pressure in the syringe.Secure the tail flat on the heating pad using the non-dominant index and middle finger. Place the middle finger proximally and the index finger distally with the puncture site between these two fingers. Slide the insulin syringe against the index finger with the eye of the needle pointing upward until it is inserted into the vein.This creates an angle of 35 degrees between the needle and the tail. Once the needle has entered the vein, blood will flow into the syringe. Slowly withdraw the plunger of the syringe at a steady rate to collect the desired volume.Remove the syringe from the tail and allow a blood drop to form on the puncture side of the tail. Aspirate this blood to collect a few more microliters of blood, in case of a non-sterile procedure. Apply pressure to the puncture site to stop the bleeding and wipe the area with a new alcohol wipe.After removing the rat from the cone, return it to its cage. The success rates with the tail vein puncture methods were compared with the success rate of the penile vein puncture method under anesthesia. Interestingly, under anesthesia, the tail vein became very unreliable and had a success rate of only 25%The success rates showed almost similar results for the tail vein puncture in conscious rats and the penile vein puncture under anesthesia.The blood sampling was performed in less than six minutes in the tail vein puncture without anesthesia, and the penile vein puncture method under anesthesia, whereas the tail vein puncture method under anesthesia took more than eight minutes due to multiple failures.

Drawing Blood from the Penile Vein

Move the plunger back and forth in the syringe several times to smoothen the withdrawal and then pull on the plunger to create negative pressure in the syringe. Retract the foreskin of the anesthetized rat from the end of the penis and hold the glands between the index and thumb pulling gently. The dorsal penile vein will appear as a superficial blue cord.With the eye of the needle pointing upward, insert the insulin syringe into the vein at an angle of 35 degrees. Once the needle has entered the vein, blood will flow into the syringe. Slowly withdraw the plunger of the syringe at a slow and steady rate to collect the desired volume.Remove the syringe. A blood drop will form on the puncture site. Aspirate the drop to collect a few more microliters of blood in case of a non-sterile procedure.Apply light pressure to the puncture site to stop the bleeding and wipe the area with a new alcohol wipe. Place the penis back in its neutral position. After turning off the isoflurane, monitor the rat until complete recovery and return it to its cage.The blood volume collected in the dorsal penile vein puncture method under anesthesia was compared with the blood collected in the tail vein puncture method with and without anesthesia. The result shows that the penile vein puncture method under anesthesia and the tail vein puncture method without anesthesia yielded comparable quantities of blood.