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

Estudo Comparativo de Técnicas de Coleta de Sangue em Ratos

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 em destaque: métodos de coleta de sangue dependentes do contexto em ratos 

Veia Caudal e Punção Peniana Modificadas para Coleta de Sangue no Modelo de Rato

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  

Punção da veia caudal sem anestesia

Para começar, prenda o rato em um cone de contenção de plástico, feche a grande extremidade do cone em torno da base da cauda. Certifique-se de que o animal esteja confortável e que a respiração seja irrestrita durante todo o procedimento. Mergulhe a cauda em água morna por cerca de um minuto para dilatar a veia e seque a cauda com um papel toalha.No contenção, posicione o animal virado para baixo com a cauda deitada em uma almofada de aquecimento. Para selecionar a veia caudal apropriada para amostragem, gire todo o animal para o lado direito ou esquerdo. Use o terço terminal da cauda para punção dos vasos sanguíneos, uma vez que os vasos se tornam mais superficiais nesta zona.Limpe a cauda com lenços de etanol 70% no local da perfuração e coloque-a na borda da almofada de aquecimento, criando um ângulo no terço terminal da cauda. Isso traz a veia para a superfície e cria mais espaço para a coleta da amostra. Para a amostragem de sangue, mova o êmbolo para frente e para trás na seringa várias vezes para suavizar a retirada e, em seguida, puxe o êmbolo para criar pressão negativa na seringa.Fixe a cauda na almofada de aquecimento usando o dedo indicador e médio não dominante. Posicionar o dedo médio proximalmente e o indicador distalmente com o local da punção entre esses dois dedos. Deslize a seringa de insulina contra o dedo indicador com o olho da agulha apontando para cima até que seja inserida na veia.Isso cria um ângulo de 35 graus entre a agulha e a cauda. Uma vez que a agulha tenha entrado na veia, o sangue fluirá para a seringa. Retire lentamente o êmbolo da seringa a uma taxa constante para recolher o volume desejado.Retire a seringa da cauda e deixe formar uma gota de sangue no lado de punção da cauda. Aspirar esse sangue para coletar mais alguns microlitros de sangue, no caso de um procedimento não estéril. Aplique pressão no local da punção para parar o sangramento e limpe a área com um novo lenço com álcool.Depois de remover o rato do cone, devolva-o à sua gaiola. As taxas de sucesso com os métodos de punção da veia caudal foram comparadas com a taxa de sucesso do método de punção da veia peniana sob anestesia. Curiosamente, sob anestesia, a veia caudal tornou-se muito pouco confiável e teve uma taxa de sucesso de apenas 25%As taxas de sucesso mostraram resultados quase semelhantes para a punção da veia caudal em ratos conscientes e a punção da veia peniana sob anestesia.A coleta de sangue foi realizada em menos de seis minutos na punção da veia caudal sem anestesia, e o método de punção da veia peniana sob anestesia, enquanto o método de punção da veia caudal sob anestesia levou mais de oito minutos devido a múltiplas falhas.

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 ...