Cleveland Family Study

10.9 Pre-Ultrasound Preparation

The brachial ultrasound procedure will be performed in the morning. Patients will minimize their activities and fast (only water allowed) for 12 hours prior to the procedure.

10.9.1 Patient Preparation

The procedure (e.g., duration of exam, BP cuff inflation/deflation, ECG electrodes, etc.) will be briefly explained to the patient to reduce anxiety and gain the patient’s cooperation. A signed informed consent must be obtained prior to any study-related procedures.

The patient’s left arm will be scanned if the ultrasonographer only scans with his/her left hand. The patient’s right arm will be scanned if the ultrasonographer only scans with his/her right hand. Therefore, the ultrasonographer can rest his/her forearm, wrist and hand on top of the patient’s forearm, increasing the likelihood of a more stable image acquisition and decreasing the possibility of the patient moving his/her arm during the procedure. If the ultrasonographer is able to scan his/her right or left hand and the study site is able to accommodate both types of scanning, the patient’s non-dominant arm will be scanned. The ultrasonographer will record the arm scanned for the procedure. The patient’s same arm will be scanned for subsequent procedures. An arm with a dialysis access graft should not be used as the procedure arm. If the patient has had a mastectomy, the procedure will be performed on the contralateral arm.

• The patient will lie supine on a bed with the head elevated just enough for comfort.
• The procedure arm will be comfortably extended and externally rotated. A blanket folded to a size of 18”x7” will be placed under the patient’s arm as a pad to provide support.
• The patient’s BP will be monitored every three to five minutes for safety purposes utilizing an automated sphygmomanometer with the BP cuff placed around the patient’s non-procedure arm. Alternatively, a standard BP cuff can be used. In this case, and additional staff member will need to obtain the blood pressure readings.
• Three ECG electrodes from the ultrasound system will be attached to the patient in a lead II configuration and a clear QRS configuration will be obtained from which diameter measurements will be made typically at end-diastole (peak R wave).
• A manual inflation, narrow-width occlusion cuff (not adult size) will be placed high as possible on the patient’s procedure arm. This will be used as an occlusion device to create reactive hyperemia. To help facilitate the procedure, the cuff will be connected to a floor-standing automated sphygmomanometer, allowing the ultrasonographer the mobility of his/her hands.
• If a narrow-width occlusion cuff is not available, a pediatric BP cuff should be used to provide sufficient room to scan between the distal end of the cuff and the bifurcation of the brachial into the radial and ulnar arteries.
• If the patient’s arm is large in circumference, creative solutions such as Velcro or carefully placed safety pins will be necessary to prevent the cuff from popping off during inflation, since pediatric cuffs are short in length.
• The patient’s procedure hand will be supinated to his/her palm faces the ceiling.
• The patient will be instructed to relax the muscles of the arm. This position helps expose the brachial artery.
• The patient will rest for 15 minutes in the reclined position before the procedure is started. The start of the “rest” time will be recorded on the data collection worksheet.

10.9.2 Scan Preparation

The appropriate exam type, such as peripheral artery, will be selected on the ultrasound machine. All ultrasound manufacturers determine the optimum operational settings, for every model ultrasound machine and for each of the different exams to be performed. If the ultrasound machine does not have a vascular package, select an application designed for superficial structures such as small parts, musculoskeletal or breast.

However, since the ultrasonic evaluation of vasoactivity is not yet a common application, the ultrasonographer will probably need to modify the exam presets. After the appropriate settings are determined for the ultrasound machine, they will be stored to increase efficiency and reproducibility. The user-defined preset should be saved on a floppy or optical disc so that it can be reloaded in case of inadvertent erasure.

Typical presets for this application will include:

• Depth of 4 cm
• Initial transmit power in the range of 2% so as not to saturate the area of interest
• Highest image line density

The patient ID will be entered as follows: patient initials, screening number, and protocol number. The annotation will be indicated as “UA BL” (i.e., upper arm baseline) and a S-VHS videocassette tape will be loaded into the VCR and the tape counter will be reset to zero. Only three procedures will be recorded per videocassette tape.