Which of the following is the correct angle of insertion when performing venipuncture using the evacuated tube method?
50°
30°
90°
75°
The Correct Answer is B
Choice A Reason:
An angle of 50° is too steep for venipuncture and increases the risk of going through the vein and causing injury to structures beneath it. A steeper angle can also make it more difficult to control the depth of the needle, leading to an increased chance of puncturing the posterior wall of the vein.
Choice B Reason:
An angle of 30° is the recommended angle for venipuncture as it allows for a smooth entry into the vein without going too deep. This angle helps to ensure that the needle enters the vein in a controlled manner and minimizes the risk of injury to the patient. It also provides a good balance between ease of entry and control over the needle's depth.
Choice C Reason:
An angle of 90° is not recommended for venipuncture because it is perpendicular to the skin, which greatly increases the risk of passing through the vein entirely and causing injury. This angle does not allow for any control over the depth of the needle and is likely to cause discomfort or pain to the patient.
Choice D Reason:
An angle of 75° is also too steep for safe venipuncture. Similar to a 50° angle, it increases the risk of penetrating the posterior wall of the vein and potentially damaging surrounding tissues or arteries. It is important to use a lower angle to ensure the safety and comfort of the patient during the procedure.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
Choice A reason:
Simply observing the site to see if the hematoma worsens is not an appropriate response. While monitoring the development of a hematoma is part of the process, it is not a proactive measure to address the immediate issue. The phlebotomist must take action to prevent further injury or complication.
Choice B reason:
Asking the patient to apply pressure may be part of the post-venipuncture care, especially after the needle has been removed, to aid in stopping any bleeding. However, this does not address the immediate concern of a developing hematoma during the draw.
Choice C reason:
Releasing the tourniquet and stopping the draw is the correct action to take when a hematoma is observed. This response is in line with the standard procedure for when a complication arises during venipuncture. Stopping the draw helps prevent further blood from pooling and exacerbating the hematoma.
Choice D reason:
While calling for a nurse and assessing the patient's condition is important, especially if the phlebotomist needs assistance or the patient shows signs of distress, it should not be the first action taken. The immediate response should be to address the hematoma by stopping the draw.
Correct Answer is A
Explanation
Choice A Reason:
The evacuated tube system is designed for the collection of multiple blood specimens using interchangeable tubes. This system utilizes a double-pointed needle, one end of which goes into the patient's vein and the other into a vacuum tube. As the blood is drawn, it automatically fills the tube until the vacuum is exhausted. The phlebotomist can then easily replace the filled tube with another without removing the needle from the patient's vein, allowing for multiple samples to be taken during a single venipuncture.
Choice B Reason:
The hypodermic needle and syringe system is typically used for manual blood draws when the evacuated tube system is not suitable, such as with small or fragile veins. This system does not use interchangeable tubes; instead, the blood is drawn into a syringe and then transferred into the appropriate tubes, which can be time-consuming and increase the risk of hemolysis or contamination.
Choice C Reason:
A winged infusion set, also known as a butterfly needle, is often used for patients with difficult veins. Like the hypodermic needle and syringe system, it does not inherently allow for the use of interchangeable multi-sample tubes. Blood is collected into a syringe or a single tube attached to the butterfly needle, and changing tubes usually requires a new puncture for each sample.
Choice D Reason:
The lancet microcollection system is used for capillary blood collection, typically from a fingerstick or heelstick. It is used for small volume samples and does not accommodate interchangeable multi-sample tubes. This method is commonly used for pediatric patients or when only a small amount of blood is needed.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today