The article reports results from the largest international dose survey in paediatric computed tomography (CT) in 32 countries and proposes international diagnostic reference levels (DRLs) in terms of ...computed tomography dose index (CTDI vol) and dose length product (DLP). It also assesses whether mean or median values of individual facilities should be used. A total of 6115 individual patient data were recorded among four age groups: <1 y, >1-5 y, >5-10 y and >10-15 y. CTDIw, CTDI vol and DLP from the CT console were recorded in dedicated forms together with patient data and technical parameters. Statistical analysis was performed, and international DRLs were established at rounded 75th percentile values of distribution of median values from all CT facilities. The study presents evidence in favour of using median rather than mean of patient dose indices as the representative of typical local dose in a facility, and for establishing DRLs as third quartile of median values. International DRLs were established for paediatric CT examinations for routine head, chest and abdomen in the four age groups. DRLs for CTDI vol are similar to the reference values from other published reports, with some differences for chest and abdomen CT. Higher variations were observed between DLP values, based on a survey of whole multi-phase exams. It may be noted that other studies in literature were based on single phase only. DRLs reported in this article can be used in countries without sufficient medical physics support to identify non-optimised practice. Recommendations to improve the accuracy and importance of future surveys are provided.
Breast screening campaign in Macedonia started in the end of 2007 and 19 national mammography departments were included. Contrary to the European Guidelines for Quality Assurance in Mammography ...Screening, the quality assurance activities were not implemented before the start of the campaign, except at the University Clinic of Radiology, Skopje. The quality control tests were performed for the very first time at 13 mammography units under a licence-obtaining procedure. One of the machines was suspended from clinical and screening practice due to heavy malfunction of the generator, X-ray tube and automatic exposure control (AEC) system. Only 3 of the 13 mammography machines met the criteria for tube voltage (kV) accuracy. Two of the seven AEC systems were calibrated in the optimal optical density (OD) range (OD >1.4). AEC settings corresponded to the recommendations at eight units, while nine units met basic overall image quality criteria. Mean glandular dose (MGD) was higher than the recommended level of 2.5 mGy in four departments. Mean gradient of the film G
0.25-2.0 was below 2.8 at four units. Only two light boxes had a luminance of >1700 cd m−2 and six rooms had an ambient light level of <50 lx. The findings of this work clearly suggest that the performance of the mammography equipment involved in the campaign in almost 50 % do not supply basic quality criteria for a breast screening programme.
The aims of this study were to investigate the frequency of computed tomography (CT) examinations for paediatric patients below 15 y of age in 128 CT facilities in 28 developing countries of Africa, ...Asia and Eastern Europe and to assess the magnitude of CT doses. Radiation dose data were available from 101 CT facilities in 19 countries. The dose assessment was performed in terms of weighted CT dose index (CTDIw), volume CT index and dose length product (DLP) for chest, chest (high resolution), lumbar spine, abdomen and pelvis CT examinations using standard methods. The results show that on average the frequency of paediatric CT examinations was 20, 16 and 5 % of all CT examinations in participating centres in Africa, Asia and Eastern Europe, respectively. Eleven CT facilities in six countries were found to use adult CT exposure parameters for paediatric patients, thus indicating limited awareness and the need for optimisation. CT images were of adequate quality for diagnosis. The CTDIw variations ranged up to a factor of 55 (Africa), 16.3 (Asia) and 6.6 (Eastern Europe). The corresponding DLP variations ranged by a factor of 10, 20 and 8, respectively. Generally, the CTDIw and DLP values in Japan are lower than the corresponding values in the three regions in this study. The study has indicated a stronger need in many developing countries to justify CT examinations in children and their optimisation. Awareness, training and monitoring of radiation doses is needed as a way forwards.
The purpose of this prospective study at 73 facilities in 18 countries in Africa, Asia and Eastern Europe was to investigate if the CT doses to adult patients in developing countries are higher than ...international standards. The dose assessment was performed in terms of weighted computed tomography dose index (CTDIw) and dose length product (DLP) for chest, chest (high resolution), lumbar spine, abdomen and pelvis CT examinations using standard methods. Except in one case, the mean CTDIw values were below diagnostic reference level (DRL) while for DLP, 17 % of situations were above DRLs. The resulting CT images were of adequate quality for diagnosis. The CTDIw and DLP data presented herein are largely similar to those from two recent national surveys. The study has shown a stronger need to create awareness and training of radiology personnel as well as monitoring of radiation doses in many developing countries so as to conform to the ALARA principle.
What is the relationship between blood tests for iron deficiency, including anaemia, and the response to intravenous iron in patients with heart failure?
In the IRONMAN trial, 1137 patients with ...heart failure, ejection fraction ≤ 45%, and either serum ferritin < 100 µg/L or transferrin saturation (TSAT) < 20% were randomized to intravenous ferric derisomaltose (FDI) or usual care. Relationships were investigated between baseline anaemia severity, ferritin and TSAT, to changes in haemoglobin from baseline to 4 months, Minnesota Living with Heart Failure (MLwHF) score and 6-minute walk distance achieved at 4 months, and clinical events, including heart failure hospitalization (recurrent) or cardiovascular death.
The rise in haemoglobin after administering FDI, adjusted for usual care, was greater for lower baseline TSAT (Pinteraction < .0001) and ferritin (Pinteraction = .028) and more severe anaemia (Pinteraction = .014). MLwHF scores at 4 months were somewhat lower (better) with FDI for more anaemic patients (overall Pinteraction = .14; physical Pinteraction = .085; emotional Pinteraction = .043) but were not related to baseline TSAT or ferritin. Blood tests did not predict difference in achieved walking distance for those randomized to FDI compared to control. The absence of anaemia or a TSAT ≥ 20% was associated with lower event rates and little evidence of benefit from FDI. More severe anaemia or TSAT < 20%, especially when ferritin was ≥100 µg/L, was associated with higher event rates and greater absolute reductions in events with FDI, albeit not statistically significant.
This hypothesis-generating analysis suggests that anaemia or TSAT < 20% with ferritin > 100 µg/L might identify patients with heart failure who obtain greater benefit from intravenous iron. This interpretation requires confirmation.
Prenatal and postnatal exposure to cigarette smoke is associated with an increased incidence of the sudden infant death syndrome, although the cause(s) for this is unknown. Tobacco glycoprotein ...(TGP), a group of proteins purified from cured tobacco leaves and present in cigarette smoke, have been shown to cause anaphylaxis in excised hearts and lungs of adult rabbits that were neonatally sensitized to TGP and later rechallenged. We sought to determine whether anaphylaxis occurred in live infant rabbits who were neonatally sensitized to TGP. At the age of 1 day, 12 animals were sensitized to TGP (0.1
mg in 0.25
cc alum) via intraperitoneal injection (ipi) followed by a booster ipi at the age of 30 days (TGP-S). Seven animals received ipi of antigen-free alum only (controls). All animals underwent an intravenous TGP challenge at age 42±2 days. Heart rate (HR) and respiratory rate (RR) were recorded for 2
min prior to and 5
min after the challenge. Baseline HR (∼260) and RR (∼120) were similar in all animals. Seven TGP-S animals developed apnea (1.9–4.7
s) within 60
s of the challenge while none of the controls did. The TGP-S also became bradycardic (the lowest HR over 50 consecutive beats), with the HR decreasing from 260 to 220 vs the controls, whose HR remained constant (∼250). We conclude that some rabbits neonatally sensitized to TGP develop apnea and bradycardia upon further intravenous TGP challenge. These studies suggest that cigarette smoke exposure may be associated with a higher rate of SIDS via an anaphylactic mechanism.
W. M. Gershan, H. V. Forster, T. F. Lowry, M. J. Korducki, A. L. Forster, M. A. Forster, P. J. Ohtake, E. A. Aaron and A. K. Garber
Department of Pediatrics, Medical College of Wisconsin, Milwaukee ...53226.
This study was done to determine 1) whether goats demonstrate the roll-off
phenomenon, i.e., a secondary decrease in minute ventilation (VE), after an
initial hyperventilation during various levels of hypoxia and, if so, 2)
whether roll-off could be due to changes in metabolic rate. We hypothesized
that roll-off occurs in the goat during hypoxia but is not due to
hypometabolism. To answer question 1, eight unanesthetized adult goats were
exposed to 15-20 min of hypoxia at 0.15, 0.12, and 0.09 inspired O2
fraction (FIO2), resulting in 60, 40, and 30 Torr arterial PO2,
respectively. Goats were fitted with a face mask connected to a spirometer
to measure VE, and arterial blood gas samples were obtained via carotid
arterial catheters. Roll-off was seen with 0.15 and 0.12 FIO2, whereas VE
steadily increased with 0.09 FIO2. During hypoxia, arterial PCO2 fell 2, 3,
and 7 Torr at 0.15, 0.12, and 0.09 FIO2, respectively. In the second series
of experiments, nine different goats were exposed to 30 min of 0.12 FIO2.
O2 consumption and CO2 production were measured five times during baseline
and hypoxia. VE increased to 32% above baseline values after 2 min of
hypoxia and then gradually decreased by 18%. Changes in breathing frequency
and tidal volume contributed to the roll-off. O2 consumption decreased (P =
0.0029, analysis of variance) and CO2 production increased (P = 0.0027)
during hypoxia, although both changes were small (< 7%) compared with
the eventual 18% decrease in VE. We conclude that the adult goat
demonstrates the roll-off phenomenon during moderate levels of hypoxia.
The purpose of this study was to identify risk factors for pediatric asthma emergency department (ED) visits. A cross sectional sample of 307 families (24%) responded to a mailed survey. Respondents ...were similar to the target population of 2487 children with asthma. Thirty seven percent of respondents had two or more asthma ED visits in the past year. Asthma ED use was associated with persistent asthma symptoms, parents without high school diplomas, age under 4 years, African-American race/ethnicity, use of written care plans, and use of spacers at school. The latter two variables were associated with severe asthma. High risk children can be targeted for office based medical care.
Doxapram was administered orally to six premature babies (3 males, 3 females) with refractory apnea at a mean gestational age of 29 +/- 2.3 weeks, mean birthweight of 1142 +/- 359 gm and a mean ...postnatal age of 24 days. They received 12, 24, and 36 mg/kg/6 hr on day 1, 2, and 3, respectively, assuming a bioavailability of 50%. Serial plasma doxapram concentrations, determined by high-performance liquid chromatography, increased with incremental doses. The drug underwent oxidative metabolism, producing ketodoxapram, the plasma concentration of which remained stable during treatment. The ratio of plasma concentrations to oral doses ranged from 0.10 to 0.12, suggesting that doxapram is poorly absorbed in the newborn. Oral doxapram may replace the intravenous infusion but doses may have to be increased to, but not exceeding, 24 mg/kg/6 hr to achieve therapeutic plasma concentrations. Interpatient variability, poor absorption and gastrointestinal adverse effects caution against the routine use of oral doxapram.
