Iodinated Contrast Media Substitution to Prevent Recurrent Hypersensitivity Reactions: A Systematic Review and Meta-Analysis.

Background Changing iodinated contrast media (ICM) may reduce the risk of recurrent ICM-induced hypersensitivity reactions in patients with a prior reaction. Purpose To perform a systematic review on the effectiveness of ICM change in comparison with no change to prevent recurrent ICM immediate hypersensitivity reactions. Materials and methods Multiple data bases were searched without language restriction between January 1990 and August 2021 to identify comparative studies of any design that included patients with a prior ICM hypersensitivity reaction to low-osmolality ICM and re-exposure to intravascular ICM. The methods used included a duplicate assessment of eligibility, double extraction of quantitative data, validity assessment, and random-effects meta-analysis. The primary outcome was the incidence of all-grade immediate recurrent hypersensitivity reactions. Secondary outcomes were the incidence of severe immediate recurrent hypersensitivity reactions and other adverse events associated with ICM change. Results Six retrospective observational studies at moderate to severe risk of bias assessed 7155 adult patients (4329 in the ICM change group and 2826 in the no-change group). Studies adopted nonstandardized switching methods, and the proportions of the ICM change group ranged between 19% (five of 27 examinations) and 80% (3104 of 3880 examinations). A Bayesian meta-analysis revealed that changing ICM was associated with a reduced risk of recurrent hypersensitivity reaction by 61% (risk ratio = 0.39; 95% credible interval [CrI]: 0.24, 0.58). The wide-ranging estimates of risk reduction were not explained by the risk of bias ratings, the event rates in the no-change group, the index-reaction severity, or the co-administered nonstandard premedication. Rare severe recurrent reactions (five studies with five events) precluded a conclusion (risk ratio = 0.34, favoring ICM change; CrI: 0.01, 3.74). Adverse events associated with ICM change were not reported. Conclusion In observational evidence of limited quality, iodinated contrast media (ICM)-change was associated with a reduced risk of recurrent immediate hypersensitivity reaction in patients with a prior ICM-induced hypersensitivity reaction. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by McDonald in this issue.

Th17 Cells Participate in Thy1.1 Glomerulonephritis Which Is Ameliorated by Tacrolimus.

INTRODUCTION: Thy1.1 glomerulonephritis (Thy1.1 GN) in rats is widely used as an experimental model of mesangial proliferative glomerulonephritis (GN). We previously reported that T-helper (Th) cells were accumulated in glomeruli from the early phase of this model and that not Th2 cells but Th1 cells play an important role in the development of glomerular alterations. Although Th17 is reported to be involved in the pathogenesis of several autoimmune diseases, the role of Th17 cells in the pathogenesis of mesangial alterations in Thy1.1 GN remains unclear. METHODS: The kinetics of the infiltration of subsets of Th cells and the expression of IL-17 in Thy1.1 GN were analyzed. Next, the localization and the cell types of IL-17 receptor (IL-17R)-positive cells and IL-6-positive cells were analyzed. Then, the effect of tacrolimus on the expressions of Th17-related cytokines in Thy1.1 GN was analyzed. RESULTS: Not only Th1 cells but also Th17 cells were recruited into glomeruli from the early phase of the disease. mRNA expression of IL-17 in glomeruli was elevated. The increased positive expression of IL-17R was detected in the mesangial area, and some of IL-17R-positive cells were co-stained with IL-6. Tacrolimus treatment ameliorated mesangial alterations by suppressing the expressions of Th17-related cytokines such as IL-17 and IL-6. CONCLUSION: Th17 cells participate in the development of Thy1.1 GN, a mimic of mesangial proliferative GN, and Th17 cells and their related cytokines are pertinent therapeutic targets.

Establishment of monoclonal antibodies broadly neutralize infection of hepatitis B virus.

Antibodies against hepatitis B virus S protein can protect against hepatitis B virus (HBV) infection. Therefore, hepatitis B immunoglobulin (HBIG), which contains HBsAb, is used clinically as a therapy for HBV infection. In this study, a series of monoclonal antibodies that recognize multiple HBV genotypes was obtained. All the antibodies recognized conformational epitopes of S protein, but not linear epitopes. Several antibodies neutralized HBV infection and exhibited strong affinities and neutralizing activities. Antigenic epitope analysis demonstrated that they recognized residue Ile152 of S protein, which is localized outside the "a" determinant. Ile152 is highly conserved, and a mutation in this residue resulted in reduced expression of large hepatitis B surface proteins (L protein), suggesting that the amino acid at this position is involved in the expression of L protein. In addition, the antibodies neutralized the infection of hepatitis D virus possessing a Gly145 mutation to Arg in S protein, which is a well-known escape mutation against HBIG treatment. Using mouse monoclonal antibodies, a humanized antibody possessing affinities and neutralizing activities similar to those of the original mouse antibody was successfully established. The antibodies generated in this study may have the potential for use in alternative antibody therapies for HBV infection.

Neurosurgical Pathology and Management of Limited Dorsal Myeloschisis Associated with Congenital Dermal Sinus in Infancy.

BACKGROUND: Because of the shared origin of limited dorsal myeloschisis (LDM) and congenital dermal sinus (CDS), CDS elements may be found within the fibroneural LDM stalk. When part of the CDS invested in the intradural stalk is left during untethering surgery, inclusion tumors such as dermoid cysts may develop. However, the most appropriate surgical strategy for LDM with CDS is still under debate. METHODS: Of 19 patients with LDM, 3 (15.8%) had histologically verified CDS elements. We retrospectively analyzed the clinicopathological findings of these patients. RESULTS: In patient 1, the entire stalk including a tiny dermoid cyst at the intradural stalk could be resected through two-level laminectomy during untethering at 6 months of age. In patients 2 and 3, the stalk appeared to be a typical LDM stalk during the initial surgery at 18 and 7 days, respectively; however, CDS was histologically diagnosed in the proximal severed end of the stalk. Postoperative three-dimensional heavily T2-weighted imaging demonstrated spherical enlargement of the remnant stalk, and the entire length of the remnant stalk including newly developed dermoid was resected during the second surgery at 3 years 11 months and 11 months, respectively. Histopathologically, glial fibrillary acidic protein-immunopositive neuroglial tissues and CDS elements were mainly located at the proximal and distal sites of the stalk, respectively, supporting the "dragging down and pulling up" theory. In patients 2 and 3, however, the proximal head of the dermoid cyst passed the distal head of the neuroglial tissues and located at the stalk-cord attachment. CONCLUSION: Surgeons should be aware of the approximately 10% possibility of the coexistence of CDS when managing infant LDM. However, the recommendation for excision of the entire length of the LDM stalk in all patients should be more carefully made because such a strategy may result in an unnecessary extent of laminotomy/laminectomy for most patients with pure LDM. However, once the postoperative histological examination reveals coexistence of CDS in the resected proximal part of the stalk, the entire length of the remnant stalk should be excised as soon as possible.

Validity of a disposable catheter to drain urine overnight in neurogenic bladder.

BACKGROUND: Overnight catheter drainage (OCD) is introduced to avoid overdistention of the bladder at night-time when clean intermittent catheterization proves ineffective for daytime management of neurogenic bladder. We adopted OCD using disposable silicone no-balloon (DSnB) catheters, with the distal end outside the body opening into diapers. OCD using DSnB catheter, however, had risks of retrograde bacterial contamination. Therefore, in this study, the validity of equipping DSnB catheters with check valves to prevent retrograde bacterial contamination was examined. METHODS: For the in vitro study, excised saline-filled swine bladders were drained using DSnB catheters with or without check valves, and the time required for intravesical pressure to reach 5 cmH2 O was measured. For the in vivo study, in cross-over experiments comparing DSnB catheters with and without check valves, OCD using DSnB catheters for 10 h was performed in rabbits under analgesia. Bacterial growth from urine samples before and after OCD and residual urine volume were examined. RESULTS: For the in vitro experiment, the median drainage time was 368.2 s (range, 88-1,085 s) and 344.7 s (range, 28-840 s) with and without check valves, respectively (n = 6), which was not significantly different. For the in vivo experiment, in cross-over experiments (n = 8) new bacterial growth rates after OCD did not differ, and median residual urine volume was 17.1 mL (range, 0-75 mL) and 1.2 mL (range, 0-5 mL) with and without check valves, respectively (P = 0.055). CONCLUSIONS: Installing a check valve in the DSnB catheter did not decrease new bacterial growth, while tending to increase residual urine volume. DSnB catheters without check valves appear to be better for continuous drainage of urine from bladder.

Bringing the Real World Into Developmental Science: A Commentary on Weber, Fernald, and Diop (2017).

This article examines the parent intervention program evaluated by Weber et al. (2017) and argues that there are scientific and ethical problems with such intervention efforts in applied developmental science. Scientifically, these programs rely on data from a small and narrow sample of the world's population; assume the existence of fixed developmental pathways; and pit scientific knowledge against indigenous knowledge. The authors question the critical role of talk as solely providing the rich cognitive stimulation important to school success, and the critical role of primary caregivers as teachers of children's verbal competency. Ethically, these programs do not sufficiently explore how an intervention in one aspect of child care will affect the community's culturally organized patterns of child care.

Successful Management of Fulminant Guillain-Barré Syndrome and Its Complications.

A 3-year-old girl presented with muscle weakness of her limbs and trunk 6 days after developing symptoms of common cold. Two days later, she experienced respiratory arrest with a Glasgow Coma Scale score of 3, necessitating endotracheal intubation. Therefore, she was transferred to our hospital with suspected acute encephalopathy. Although no abnormalities were observed on brain and spinal magnetic resonance imaging and electroencephalography, peripheral nerve conduction velocity tests failed to evoke motor and sensory nerve action potentials. Thus, we gave a diagnosis of fulminant Guillain-Barré syndrome and initiated immunoglobulin therapy. On day 3 of admission, she developed sinus tachycardia that induced circulatory failure and oliguria, which was successfully treated with landiolol. Subsequently, we performed plasmapheresis followed by immunoglobulin and steroid pulse therapies. She was weaned off the mechanical ventilator by day 20 of admission, was ambulatory by day 44, and had completely recovered without any adverse sequelae by day 55. In conclusion, landiolol was effective for treating acute sinus tachycardia-induced circulatory failure and played a key role in saving the life of this patient.

Partition Function and Configurational Entropy in Non-Equilibrium States: A New Theoretical Model.

A new model of non-equilibrium thermodynamic states has been investigated on the basis of the fact that all thermodynamic variables can be derived from partition functions. We have thus attempted to define partition functions for non-equilibrium conditions by introducing the concept of pseudo-temperature distributions. These pseudo-temperatures are configurational in origin and distinct from kinetic (phonon) temperatures because they refer to the particular fragments of the system with specific energies. This definition allows thermodynamic states to be described either for equilibrium or non-equilibrium conditions. In addition; a new formulation of an extended canonical partition function; internal energy and entropy are derived from this new temperature definition. With this new model; computational experiments are performed on simple non-interacting systems to investigate cooling and two distinct relaxational effects in terms of the time profiles of the partition function; internal energy and configurational entropy.

Ability of a novel system for neonatal extracorporeal renal replacement therapy with an ultra-small volume circuit to remove solutes in vitro.

BACKGROUND: We automated our manual, syringe-driven extracorporeal renal replacement therapy (eRRT) system with an ultra-small volume circuit (3.2 ml) that is suitable for neonates without blood priming. Our objective was to determine the solute clearance and water balance of the automated and manual systems in vitro. METHODS: Stored whole blood samples containing exogenous urea, creatinine (Cr), potassium (K), and ammonia (NH3) to imitate acute kidney injury (AKI) and hyperammonemia were dialyzed for 3 h (blood flow, 4.0 ml/min; dialysate flow, 600 ml/h) with a continuous infusion of heparin. Solute clearance and sample weight were then compared with values before dialysis. RESULTS: The median clearance of blood urea nitrogen, Cr, K, and NH3 ranged from 1.7 to 2.3 and from 2.4 to 2.6 ml/min, and the median weight of the samples was decreased by 3.8 g and increased by 8.3 g after 3 h of dialysis using the manual and automated systems, respectively. CONCLUSIONS: The automated system effectively cleared solutes, but safety concerns were associated with platelet consumption and fluid balance. Additional studies are needed to establish the safety and accuracy of this novel system for clinical use in neonates and preterm infants.

Solitary fibrous tumors in the extremities: imaging findings for six patients.

The purpose of this study was to describe the magnetic resonance imaging (MRI) and computed tomography (CT) findings for solitary fibrous tumors (SFTs) in the extremities in correlation with histopathological findings. Between 2006 and 2013, 6 consecutive patients with SFT in an extremity were studied with MRI (6 patients) and CT (4 patients). Diffusion-weighted images were also performed in 3 patients and dynamic contrast-enhanced CT in 2 patients. All 6 tumors were diagnosed after surgical excision, and the pre-surgical imaging findings were correlated with the histopathological findings. As a result, all 6 patients were female, and each had a clearly palpable, well-circumscribed, round or oval mass adjacent to fascia in an extremity, of less than 10 cm maximum diameter in 5 patients. On MRI, the tumors were iso-intense with muscle on T1-weighted image, and appeared heterogeneous and high-intensity on T2-weighted image. After injection of a contrast agent, the tumors demonstrated strong enhancement. A vascular pedicle was detected in 4 patients with tumors having a maximum diameter more than 5 cm. Diffusion-weighted images demonstrated high signal intensities, and apparent diffusion coefficient values were iso to high compared to muscle (from 1.41-2.10×10(-3) mm(2)/s). All the tumors were benign histopathologically and clinically. In 1 patient, the imaging appearance revealed underlying histopathological components, including fibrous-rich, cellular-rich, and myxoid change areas. In conclusion, a SFT in an extremity comprises a well-circumscribed mass adjacent to fascia having a fibrous-dominant area, strong contrast enhancement, and a vascular pedicle.

Intratumoral hemorrhage in a patient with malignant meningioma under anticoagulant therapy.

We report the case of an elderly woman with malignant meningioma and atrial fibrillation who started taking anticoagulants after an ischemic stroke and subsequently developed intratumoral hemorrhage. Further studies are required to confirm whether a particular anticoagulant agent is suitable for patients with brain tumor and atrial fibrillation.

Comparison of the central adrenal vein and the common trunk of the left adrenal vein for adrenal venous sampling.

PURPOSE: To compare left adrenal venous sampling (AVS) in two locations: the central adrenal vein and the common trunk. MATERIALS AND METHODS: A total of 22 patients (12 men and 10 women; mean age, 50 y; range, 26-65 y) who were suspected of having primary aldosteronism (PA) and underwent successful AVS with cortisol concentration measurement and/or venography between November 2010 and August 2011 were retrospectively analyzed. In regard to the left adrenal vein, collections were done at two locations: at the common trunk below the confluence of the inferior phrenic vein and at the central adrenal vein, which was above the confluence. The effects of the inflow from the inferior phrenic vein on plasma aldosterone and cortisol levels were analyzed. RESULTS: Eight patients had bilateral hypersecreting lesions and 13 had a unilateral lesion. One was diagnosed as having secondary hypertension other than PA. The median cortisol levels below and above the confluence were 129 µg/dL (range, 21-400 µg/dL) and 215 µg/dL (range, 21-690 µg/dL), respectively. The median aldosterone levels were 2,120 pg/mL (range, 164-42,700 pg/mL) and 4,275 pg/mL (range, 119-59,000 pg/mL), respectively. The median aldosterone/cortisol (A/C) ratios were 244 (range, 34-2,401) and 278 (range, 25-2,251), respectively. Cortisol and aldosterone levels were significantly higher above the confluence (P = .0050 and P = .0003, respectively), whereas the A/C ratio showed no significant difference (P = .12). CONCLUSIONS: Although higher levels of cortisol and aldosterone were obtained upstream, A/C ratio was not significantly different between the central adrenal vein and the common trunk.

An inhaled ACE2 decoy confers protection against SARS-CoV-2 infection in preclinical models.

The Omicron variant continuously evolves under the humoral immune pressure exerted by vaccination and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and the resulting Omicron subvariants display further immune evasion and antibody escape. An engineered angiotensin-converting enzyme 2 (ACE2) decoy composed of high-affinity ACE2 and an IgG1 Fc domain could offer an alternative modality to neutralize SARS-CoV-2. We previously reported its broad spectrum and therapeutic potential in rodent models. Here, we demonstrate that the engineered ACE2 decoy retains neutralization activity against Omicron subvariants, including the currently emerging XBB and BQ.1 strains, which completely evade antibodies currently in clinical use. SARS-CoV-2, under the suboptimal concentration of neutralizing drugs, generated SARS-CoV-2 mutants escaping wild-type ACE2 decoy and monoclonal antibodies, whereas no escape mutant emerged against the engineered ACE2 decoy. Furthermore, inhalation of aerosolized decoys improved the outcomes of rodents infected with SARS-CoV-2 at a 20-fold lower dose than that of intravenous administration. Last, the engineered ACE2 decoy exhibited therapeutic efficacy for cynomolgus macaques infected with SARS-CoV-2. These results indicate that this engineered ACE2 decoy represents a promising therapeutic strategy to overcome immune-evading SARS-CoV-2 variants and that liquid aerosol inhalation could be considered as a noninvasive approach to enhance the efficacy of COVID-19 treatments.

Dispersion dependence of linewidth in actively mode-locked ring lasers.

We studied the spectral linewidth narrowing of wavelength-swept actively mode-locked ring lasers (AMLLs). The numerical calculations for the static-state AMLL led us to predict that anomalous dispersion would narrows the linewidth. We examined the effect experimentally using AMLL setups for normal and anomalous dispersive cavities via the normal or inverse use of a linearly chirped fiber Bragg grating. The experiment indicated that the cavity with anomalous dispersion always generates narrower linewidth lasers than its normal dispersion equivalent. The cavity with anomalous dispersion also achieved a 0.08 nm linewidth. Using the anomalous dispersion setup, we observed instantaneous linewidth broadening during wavelength sweeping. Although the coherence of AMLL decreased drastically when the sweep rate became very rapid beyond a single roundtrip, narrow-linewidth lasing was observed within a single roundtrip. In summary, we demonstrated the use of 150 kHz wavelength sweeping with a 40-nm range and a 2.7-m short-length anomalous dispersion cavity.

Comparison of contamination levels on the exterior surfaces of vials containing platinum anticancer drugs in Japan.

Contamination of the external surface of anticancer drug vials supplied to hospital pharmacies has been recognized as a potential health hazard. The aim of this study was to investigate the levels of contamination on the exterior surface of vials containing platinum anticancer drugs in Japan. Platinum contamination on the exterior surface of vials containing cisplatin or carboplatin was examined using products commercially available in Japan. Cisplatin vials from 42 batches (2 drug contents, 10 products and 5 manufacturers) and carboplatin vials from 28 batches (3 drug contents, 7 products and 3 manufacturers) were used. Five vials were randomly sampled from each batch. Exterior contamination levels of 0.070-144 ng/vial as cisplatin and 0.21-1630 ng/vial as carboplatin were detected. Significant differences in the levels of contamination among the batch numbers were observed in 6 of 10 cisplatin products and 6 of 7 carboplatin products. Significant differences in the levels of contamination were observed in 3 cisplatin products with different contents of drug within the vials and 1 carboplatin product with different contents of drug within the vials. Significant differences in the contamination levels among the cisplatin manufacturers but not carboplatin manufacturers were observed. The degree of contamination of the carboplatin products was significantly higher than that of the cisplatin products. In conclusion, external contamination was confirmed in all cisplatin and carboplatin vials tested. The degree of contamination was different among different batch numbers, drug contents, manufacturers, and platinum anticancer drug.

[Subdural hematoma with reversible cerebral vasoconstriction syndrome: a case report].

A 71-year-old man had persistent cervical pain secondary to thunderclap headache during sleep. MRI conducted the next morning revealed subdural hematoma and convexity subdural hemorrhage on the right occipital region, and the patient was hospitalized. MRA showed vascular narrowing in the bilateral PCA. Follow-up MRA on day 8 of admission showed aggravated vascular narrowing of PCA, indicative of reversible cerebral vasoconstriction syndrome (RCVS). The patient was treated with a calcium-channel antagonist. Post-discharge MRA showed improvement of PCA narrowing, and the diagnosis of RCVS was confirmed.

Massive hemothorax in a pregnant patient with neurofibromatosis type 1.

BACKGROUND: Reports of spontaneous hemothorax in patients with neurofibromatosis type 1 are scarce despite the severe complication. We herein present the first case of hemothorax in a neurofibromatosis type 1 patient during pregnancy and discuss the difficulty associated with its diagnosis and treatment. CASE PRESENTATION: A 39-year-old female at 34 weeks gestation presented with sudden left back pain and dyspnea. Chest radiography revealed massive left pleural effusion. Computed tomography showed bleeding from the intercostal artery. Although the patient appeared hemodynamically stable, the fetus was in a critical condition. Emergency caesarean section was performed within 1 hour. Subsequently, we performed endovascular coil embolization of the intercostal artery. While this intensive treatment saved the patient, her fetus could not be rescued. CONCLUSIONS: Patients with neurofibromatosis type 1 may develop massive hemothorax without gross lesions. In late pregnancy, sufficient infusion and quick hemostasis are essential and can be lifesaving.

Anemia Prevalence and Anthropometric Status of Indigenous Women and Young Children in Rural Botswana: The San People.

In Botswana, there is limited data available on the health and nutritional status of the San People (also known as the Basarwa or Bushmen), an Indigenous minority group primarily living in the Ghanzi District. Our aim in this study was to assess anemia prevalence among and anthropometric indices of women and young children in Ghanzi District through a cross-sectional survey. We recruited 367 mother-child pairs (women 15-49 years and children 6-59 months) in nine randomly selected areas. A capillary blood sample was collected, and weight and height were measured. Hemoglobin (Hb) concentration was measured with use of a hemoglobinometer (HemoCue, AB), as per global recommendations. Overall, adjusted anemia prevalence was 12% in non-pregnant women (Hb < 120 g/L), 26% in pregnant women (Hb < 110 g/L), and 42% in children (Hb < 110 g/L), but it varied widely depending on whether or not the controversial factor of ethnicity was adjusted for (range of 6-26%, 22-30%, and 35-68% prevalence, respectively). Thirty-nine percent (n = 133/344) of non-pregnant women and 52% (n = 12/23) of pregnant women were underweight (BMI < 18.5 kg/m2). In children aged 6-23 months, 41% were underweight (weight-for-age z-score < -2 SD), 13% were wasted (weight-for-height z-score < -2 SD), and 65% were stunted (height-for-age z-score < -2 SD); in children aged 24-59 months, 57% were underweight, 13% were wasted, and 66% were stunted. Fifty-six percent (n = 205/367) of women self-reported smoking in any form (rolled cigarettes or snuffing). The high prevalence of smoking among women, underweight status among pregnant women, and anemia, stunting, and wasting among children is of the highest concern for public health and should be addressed in future health and nutrition programming.

Bactericidal effect of HM-242, a novel disinfectant, against Pseudomonas aeruginosa.

The bactericidal effect of HM-242, a novel antimicrobial agent, against Pseudomonas aeruginosa was investigated by using Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values and the time-kill study. Furthermore, we also morphologically investigated its effect against P. aeruginosa by use of transmission electron microscopy (TEM) in comparison with that of chlorhexidine digluconate (CHG). The bactericidal activity of HM-242 after 1 min incubation evaluated by MBC was 25 microg/mL, while the MBC of CHG was 50 microg/mL. In the time-kill study, the killing activity of HM-242 with 25 microg/mL incubation was stronger than that of CHG with 50 microg/mL incubation. MIC values of HM-242 and CHG against P. aeruginosa were 25 microg/mL and 12.5 microg/mL, respectively. We also observed via TEM the morphological changes in the test bacteria after being treated with each drug at 1/2MBC, 1MBC, 2MBC and 4MBC after 1 min or 5 min incubation. Under treatment with the same concentration of the test drugs, the cell damage with HM-242 treatment was greater than that with CHG. The appearance of empty cells was recognized at the concentrations greater than 50 microg/mL (2MBC) of HM-242 and 200 microg/mL of CHG (4MBC) after 1 min exposure, although no cell damage was evident below these concentrations. The cell-damaging effect against the test strain was dependent on the drug concentration and incubation time. The release of cell components and bleb formation were also recognized. These results suggest that HM-242 has more potent bactericidal activity in low concentrations under shorter time treatments than CHG. Both HM-242 and CHG act on the cell membrane and cell wall of P. aeruginosa and can destroy the cell integrity. We finally emphasize that HM-242 as well as CHG might be a suitable disinfectant for use in the medical field.

Pharmacologic and non-pharmacologic interventions to prevent hypersensitivity reactions of non-ionic iodinated contrast media: a systematic review protocol.

INTRODUCTION: Iodinated contrast media are commonly used in medical imaging and can cause hypersensitivity reactions, including rare but severe life-threatening reactions. Although several prophylactic approaches have been proposed for severe reactions, their effects remain unclear. Therefore, we aim to review systematically the preventive effects of pharmacologic and non-pharmacologic interventions and predictors of acute, hypersensitivity reactions. METHODS AND ANALYSIS: We will search the PubMed, EMBASE and Cochrane Central Register of Controlled Trials databases from 1 January 1990 through 31 December 2019 and will examine the bibliographies of eligible studies, pertinent review articles and clinical practice guidelines. We will include prospective and retrospective studies of any design that evaluated the effects of pharmacological and non-pharmacological preventive interventions for adverse reactions of non-ionic iodinated contrast media. Two assessors will independently extract the characteristics of the study and intervention and the quantitative results. Two independent reviewers will assess the risk of bias using standard design-specific validity assessment tools. The primary outcome will be reduction in acute contrast media-induced hypersensitivity reactions. The secondary outcomes will include characteristics associated with the development of contrast media-induced acute hypersensitivity reactions, and adverse events associated with specific preventive interventions. Unique premedication regimens (eg, dose, drug and duration) and non-pharmacological strategies will be analysed separately. Average-risk and high-risk patients will be considered separately. A meta-analysis will be performed if appropriate. ETHICS AND DISSEMINATION: Ethics approval is not applicable, as this will be a secondary analysis of publicly available data. The results of the analysis will be submitted for publication in a peer reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42019134003.