Cumulative radiation dose incurred by patients in intensive care unit at Mankweng Hospital

Abstract

BACKGROUND: Patients admitted in the Intensive Care Unit (ICU) are critically ill and may require multiple radiological imaging studies. These imaging studies may be repeated in a short space of time and patients are therefore at an increased risk of receiving high cumulative radiation dose in a single admission at a hospital. This study aimed at quantifying the amount of cumulative radiation dose incurred by patients admitted in ICU at Mankweng Hospital in a single admission. METHODOLOGY: A retrospective descriptive study design was conducted on hospital records of patients admitted to the Intensive Care Unit, in the period between 01 April 2019 and 31 March 2020. Data was collected using a data collection sheet and captured into Microsoft excel for analysis. The study applied descriptive statistics (mean, median, quantile ranges, and frequencies and percentages) to summarise the patients’ demographical information and profile. Analysis of variance was used to assess the difference between means by reason of admission. The Chi-square test was used to analyse the relationship between the reason for admission in ICU and the cumulative radiation dose incurred. Regression analysis was applied to determine the relationship between the length of ICU stay and the cumulative radiation dose incurred by patients in a single admission. Statistical Package for Social Sciences (SPSS) version 28 was used to analyse the data. RESULTS: During the study period, a total of 221 imaging studies were conducted, out of which 150 (68%) were plain X-rays and 71 (32%) were CT scans. The radiation dose received by the patients was 644mSv, with a mean of 4.9mSv. Plain X-rays were more frequent than CT scans, but contributed only 5% of the radiation dose, whereas CT scans accounted for 95% of it. The average length of stay in the ICU was 5 days, ranging from 1 to 17 days. Most patients (63.57%; n=82) stayed in the ICU for less than 5 days, while the remaining (35.66%; n=46) stayed for more than 5 days. The study also found a significant positive correlation between length of stay and X-ray (p-value <0.0001). The Chi-square test demonstrated that the cumulative radiation dose received by patients during a single admission was associated with the reasons for admission (p-value=0.03260<0.05). CONCUSION: ICU patients at Mankweng Hospital are experiencing higher radiation doses in a single admission, with CT scans being the biggest contributor of the radiation dose. Radiation dose increases with increase in length of ICU stay.