Pre‐procedure

ActionRationale

1. 1.Show
   Introduce yourself to the patient, explain and discuss the procedure with them, and gain their consent to proceed.
   To ensure that the patient feels at ease, understands the procedure and gives their valid consent (NMC [165], C).
2. 2.Show
   Wash hands with bactericidal soap and water, or decontaminate physically clean hands with alcohol‐based handrub. Apply gloves.
   To reduce the risk of cross‐infection and specimen contamination (Fraise and Bradley [62], E).
3. 3.Show
   Establish whether a trough, random or peak drug level is required. Then:

   • If trough, take sample immediately prior to next due dose.
   • If peak, the timing is drug dependent; discuss with the prescriber or pharmacist.
   • If random, take sample when convenient.
   To ensure the correct test is undertaken.

Procedure

1. 4.Show
   If venepuncture is required to obtain the sample: following venepuncture (see Procedure guideline 13.1: Venepuncture), withdraw the volume of blood appropriate to the blood sample bottle using the vacuum‐assisted collection system.
   To ensure the correct volume of blood is obtained and to reduce the safety risk to the practitioner (DH [46], [48], C).
2. 5.Show
   If a CVAD is available from which to obtain the sample: follow Procedure guideline 13.2: Central venous access devices: taking a blood sample for vacuum sampling or 13.3: Central venous access devices: taking a blood sample for syringe sampling, remembering the following:

   • The device must be flushed thoroughly before taking the blood sample.
   • Take and discard enough blood to clear the device of any residual flush solution or medications (usually 5–10 mL is sufficient), then attach the vacuum‐assisted collection system to take the drug‐level sample.
   • Indicate on the blood sample bottle and appropriate form that the sample is from a CVAD.
   To reduce contamination by previously administered therapeutic agents and to allow appropriate interpretation of the results (NPSA [167], C; RCN [211], C).
3. 6.Show
   Clearly label the blood sample bottle and appropriate form with request details (trough, peak or random) and note the time of the last administered dose.
   To ensure there is no confusion between the peak and trough drug serum level specimens (WHO [260], C).

Post‐procedure

1. 7.Show
   Ensure microbiology or biochemistry request forms are completed correctly, including date, exact time and dosage of previously administered dose.
   To maintain accurate records and provide accurate information for laboratory analysis (NMC [165], C; Weston [255], E).
2. 8.Show
   Arrange prompt delivery to pathology.
   To allow for prompt analysis and timely adjustments to patient's drug therapy regimen if indicated. E
3. 9.Show
   Document the procedure in the patient's records.
   To ensure timely and accurate record keeping (NMC [165], C; WHO [260], C).