Cardiovascular Journal of Africa: Vol 32 No 5 (SEPTEMBER/OCTOBER 2021)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 5, September/October 2021 AFRICA 273 The target population was all the cardiologists ( n = 4), radiographers ( n = 2) and nursing staff ( n = 4) working at the site. Data collection for the radiation was conducted over a one-month period. The researcher attended the site once a week and recorded all the procedures for that specific day. The total number of procedures performed for the month was 11. The sample consisted of this one hospital and the staff alternating between the cases, including three cardiologists, two radiographers, one scrub nurse and two assistant nurses, who were observed for 11 procedures. The researcher was present before, during and after the procedures as an observer by means of the checklist, without interfering in the workflow of the procedure. The TLDs were handed to staff to be attached to specific areas before preparation for the procedure, namely under the physicians’, nurses’ and radiographers’ lead glasses on the temple next to the eye closest to the X-ray tube, on the thyroid under the thyroid shield, on the hand closest to the X-ray tube during the procedure and on the dorsum of the foot (on top of the shoe) closest to the X-ray tube. The TLDs were collected from the staff once the procedure was done and attached to the next person before the following procedure started. Measurement of the distances of the feet of the staff to the X-ray tube were recorded during the procedure by the researcher without the need for the staff to work at a slower pace. Measurements were made with a measuring tape by bending under the table to be close to the feet of the staff. The researcher was wearing a personal dosimeter. The procedures were completed by three cardiologists and two radiographers taking turns. Due to the interchange of staff, it was decided that the dosimeters would not be dedicated to a specific staff member but to the person responsible for the procedure, since the aim was not to observe individuals but the safety culture of the team. Measurements of the distances of staff were handled with the same principle. All the procedures that were executed during the one-month period that the researcher was available to attend formed part of the data. Under supervision of a statistician, descriptive statistics were calculated, namely frequencies and percentages for categorical data, and means and standard deviations or medians and percentiles for numerical data. For the purpose of this article, selected criteria on the checklist (benchmarked as mentioned above) that were evaluated are listed in Table 1. Areas of non-compliance were identified and are highlighted in the table. The researcher completed the criteria for each individual participant in a Microsoft Excel spreadsheet. Results The doses to the eye, thyroid, hand and foot of the physicians, nurses, assistant (floor) nurses and radiographers involved in the procedures at the participating hospital were measured by means of finger TLDs. In total, the sample consisted of 176 measurements (four anatomical locations × 11 procedures × four categories of health workers). The dosimeter readings for the cardiologist, nurse, floor nurse and radiographer are listed in Table 2 to indicate the mSv value of the exposure measured to the eye, thyroid, hand and foot of the staff. The values for the 11 procedures to be noted are to the hand of the cardiologist (0.73 mSv), eye of the cardiologist (0.45 mSv), hand of the scrub nurse (0.65 mSv), eye of the scrub nurse (0.54 mSv), foot of the scrub nurse (0.52 mSv) and thyroid of the radiographer (0.42 mSv). In the RPS report, the deep doses below 0.15 mSv were reported as zero and the beta skin doses below 3.25 mSv were reported as zero if the deep dose was < 0.15 mSv. The effective dose for an interventionalist is typically 2–4 mSv/y, which is well below the recommended limit of 20 mSv/y. 2,12,19,20 The majority of procedures involved femoral catheterisation. The orientation of the C-arm of the X-ray machine was mainly in the posterior–anterior and lateral angulations with the image intensifier for the frontal tube above the table. The interventionalist’s and scrub nurse’s feet were at a distance of 16 to 68 cm from the X-ray tube (Table 3). The hand of the cardiologist was never in the beam. However, 36% of the time, the elbow was in the beam during fluoroscopy and also in 18% of the procedures, during acquisition of the images (cine). During the mechanical injection of contrast media, none of the staff in the theatre moved away from the patient. Other staff, such as technologists, were mostly behind a barrier. Most of the anaesthetists made use of shielding but were placed within one metre of the patients most of the time. The theatre door was frequently not closed. The fluoroscopy (screening) time ranged from 0.24 to 25.53 minutes and dose area product ranged between 102 and 11 336 mGy/cm 2 . No intermittent screening was observed, but the recommended ‘last image hold’ and ‘loop image displayed’ are used routinely. Pulsed fluoroscopy of 15 frames per second (f/s) was used and in 55% of the procedures, a frame rate of 30 f/s. Collimation and filters were used and visible on the real-time images, but in only 27% of the procedures was tight collimation observed. In this unit, none of the required and recommended table screens or ceiling-suspended screens were installed. All the floor nurses made use of one-sided lead aprons with no lead cover at the back. The thickness of the lead aprons was correctly selected, namely 0.35 mm lead (Pb) and even 0.5 mm Pb in front at the overlap. Thyroid shield thickness adhered to the minimum of 0.5 mm Pb equivalent. All the cardiologists made use of lead glasses, but only 25% of the glasses had protective sides. Headcovers were available but not used. The radiation workers were issued with one dosimeter each Table 3. Participants’ foot distance from the X-ray tube under the table Foot distance from X-ray tube (cm) Health worker Total Floor nurse Interventionalist Nurse Radiographer n (%) n (%) n (%) n (%) n (%) 16 0 (0) 0 (0) 1 (9.1) 0 (0) 1 (9.1) 40 0 (0) 1 (9.1) 0 (0) 0 (0) 1 (9.1) 46 0 (0) 0 (0) 1 (9.1) 0 (0) 1 (9.1) 53 0 (0) 1 (9.1) 0 (0) 0 (0) 1 (9.1) 54 0 (0) 0 (0) 1 (9.1) 0 (0) 1 (9.1) 57 0 (0) 3 (27.3) 0 (0) 0 (0) 3 (27.3) 61 0 (0) 1 (9.1) 0 (0) 0 (0) 1 (9.1) 62 0 (0) 1 (9.1) 1 (9.1) 0 (0) 2 (18.2) 63 0 (0) 0 (0) 1 (9.1) 0 (0) 1 (9.1) 64 0 (0) 0 (0) 1 (9.1) 0 (0) 1 (9.1) 67 0 (0) 2 (18.2) 1 (9.1) 0 (0) 3 (27.3) 68 0 (0) 2 (18.2) 4 (36.4) 0 (0) 6 (54.5) 150 0 (0) 0 (0) 0 (0) 11 (100) 11 (100) 300 11 (100) 0 (0) 0 (0) 0 (0) 11 (100)