Population pharmacokinetics of molnupiravir in adults with COVID-19: Lack of clinically important exposure variation across individuals

Effective antiviral treatments for coronavirus disease 2019 (COVID-19) are needed to reduce the morbidity and mortality associated with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection, particularly in patients with risk factors for severe disease. Molnupiravir (MK-4482, EIDD-2801) is an orally administered, ribonucleoside prodrug of β-D-N4-hydroxycytidine (NHC) with submicromolar potency against SARS-CoV-2. A population pharmacokinetic (PopPK) analysis for molnupiravir exposure was conducted using 4202 NHC plasma concentrations collected in 1207 individuals from a phase I trial in healthy participants, a phase IIa trial in non-hospitalized participants with COVID-19, a phase II trial in hospitalized participants with COVID-19, and a phase II/III trial in non-hospitalized participants with COVID-19. Molnupiravir pharmacokinetics (PK) was best described by a two-compartment model with a transit-compartment absorption model and linear elimination. Molnupiravir apparent elimination clearance increased with body weight less-than-proportionally (power 0.412) and was estimated as 70.6 L/h in 80-kg individuals with a moderate interindividual variability (43.4% coefficient of variation). Additionally, effects of sex and body mass index on apparent central volume and food status and formulation on the absorption mean transit time were identified as statistically significant descriptors of variability in these PK parameters. However, none of the identified covariate effects caused clinically relevant changes in the area under the NHC concentration versus time curve between doses, the exposure metric most closely related to clinical response. Overall, the PopPK model indicates that molnupiravir can be administered in adults without dose adjustment based on age, sex, body size, food, and mild-to-moderate renal or mild hepatic impairment.

Evaluating the cost implications of integrating SARS-CoV-2 genome sequencing for infection prevention and control investigation of nosocomial transmission within hospitals

BACKGROUND

The COG-UK hospital-onset COVID-19 infection (HOCI) trial evaluated the impact of SARS-CoV-2 whole-genome sequencing (WGS) on acute infection, prevention, and control (IPC) investigation of nosocomial transmission within hospitals.

AIM

To estimate the cost implications of using the information from the sequencing reporting tool (SRT), used to determine likelihood of nosocomial infection in IPC practice.

METHODS

A micro-costing approach for SARS-CoV-2 WGS was conducted. Data on IPC management resource use and costs were collected from interviews with IPC teams from 14 participating sites and used to assign cost estimates for IPC activities as collected in the trial. Activities included IPC-specific actions following a suspicion of healthcare-associated infection (HAI) or outbreak, as well as changes to practice following the return of data via SRT.

FINDINGS

The mean per-sample costs of SARS-CoV-2 sequencing were estimated at £77.10 for rapid and £66.94 for longer turnaround phases. Over the three-month interventional phases, the total management costs of IPC-defined HAIs and outbreak events across the sites were estimated at £225,070 and £416,447, respectively. The main cost drivers were bed-days lost due to ward closures because of outbreaks, followed by outbreak meetings and bed-days lost due to cohorting contacts. Actioning SRTs, the cost of HAIs increased by £5,178 due to unidentified cases and the cost of outbreaks decreased by £11,246 as SRTs excluded hospital outbreaks.

CONCLUSION

Although SARS-CoV-2 WGS adds to the total IPC management cost, additional information provided could balance out the additional cost, depending on identified design improvements and effective deployment.

Population pharmacokinetic analysis of the P2X3-receptor antagonist gefapixant

Gefapixant, a P2X3-receptor antagonist, demonstrated objective and subjective efficacy in individuals with refractory or unexplained chronic cough. We report a population pharmacokinetic (PopPK) analysis that characterizes gefapixant pharmacokinetics (PKs), quantifies between- and within-participant variability, and evaluates the impact of intrinsic and extrinsic factors on gefapixant exposure. The PopPK model was initially developed using PK data from six phase I studies. Stepwise covariate method was utilized to identify covariates impacting PK parameters; the model was re-estimated and covariate effects were re-assessed after integrating PK data from three phase II and III studies. Simulations were conducted to evaluate the magnitude of covariate effects on gefapixant exposure. Of 1677 participants included in this data set, 1618 had evaluable PK records. Age, body weight, and sex had statistically significant, but not clinically relevant, effects on exposure. Degree of renal impairment (RI) had statistically significant and clinically relevant effects on exposure; exposure was 17% to 89% higher in those with versus without RI. Simulation results indicated that gefapixant 45 mg administered once daily to patients with severe RI has similar exposure to gefapixant 45 mg administered twice daily to patients with normal renal function. There were no significant effects of proton pump inhibitors or food. Of evaluated intrinsic and extrinsic factors, only RI had a clinically relevant effect on gefapixant exposure. Patients with mild or moderate RI do not require dosage adjustments; however, for patients with severe RI who are not on dialysis, gefapixant 45 mg once daily is recommended.

First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9  GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36  GeV/c^{2}, rejecting cross sections above 9.2×10^{-48}  cm at the 90% confidence level.

Factors Influencing COVID-19 Risk: Insights from Molnupiravir Exposure-Response Modeling of Clinical Outcomes

Molnupiravir (MOV) is an oral antiviral for the treatment of COVID-19 in outpatient settings. This analysis investigated the relationship between β-D-N4-hydroxycytidine (NHC) pharmacokinetics (PK) and clinical outcomes in patients with mild to moderate COVID-19 in the Phase 3 part of the randomized, double-blind, placebo-controlled MOVe-OUT trial. Logistic regression models of the dependency of outcomes on exposures and covariates were constructed using a multi-step process. Influential covariates were identified first using placebo arm data, followed by assessment of exposure-dependency in drug effect using data from both the placebo and MOV arms. The exposure-response (E-R) analysis included 1,313 participants; 630 received MOV and 683 received placebo. Baseline viral load, baseline disease severity, age, weight, viral clade, active cancer, and diabetes were identified as significant determinants of response using placebo data. Absolute measures of viral load on days 5 and 10 were strong on-treatment predictors of hospitalization. An additive area under the curve (AUC)-based E_max model with a fixed Hill coefficient of 1 best represented the exposure-dependency in drug effect and the AUC50 was estimated to be 19,900 nM*hr. Patients at 800 mg achieved near maximal response which was larger than for 200 or 400 mg. The final E-R model was externally validated and predicted that the relative reduction in hospitalization with MOV treatment would vary with patient characteristics and factors in the population. In conclusion, the E-R results support the MOV dose of 800 mg twice daily to treat COVID-19. Many patient characteristics and factors impacted outcomes beyond drug exposures.

Short-term risk prediction after major lower limb amputation: PERCEIVE study

BACKGROUND

The accuracy with which healthcare professionals (HCPs) and risk prediction tools predict outcomes after major lower limb amputation (MLLA) is uncertain. The aim of this study was to evaluate the accuracy of predicting short-term (30 days after MLLA) mortality, morbidity, and revisional surgery.

METHODS

The PERCEIVE (PrEdiction of Risk and Communication of outcomE following major lower limb amputation: a collaboratIVE) study was launched on 1 October 2020. It was an international multicentre study, including adults undergoing MLLA for complications of peripheral arterial disease and/or diabetes. Preoperative predictions of 30-day mortality, morbidity, and MLLA revision by surgeons and anaesthetists were recorded. Probabilities from relevant risk prediction tools were calculated. Evaluation of accuracy included measures of discrimination, calibration, and overall performance.

RESULTS

Some 537 patients were included. HCPs had acceptable discrimination in predicting mortality (931 predictions; C-statistic 0.758) and MLLA revision (565 predictions; C-statistic 0.756), but were poor at predicting morbidity (980 predictions; C-statistic 0.616). They overpredicted the risk of all outcomes. All except three risk prediction tools had worse discrimination than HCPs for predicting mortality (C-statistics 0.789, 0.774, and 0.773); two of these significantly overestimated the risk compared with HCPs. SORT version 2 (the only tool incorporating HCP predictions) demonstrated better calibration and overall performance (Brier score 0.082) than HCPs. Tools predicting morbidity and MLLA revision had poor discrimination (C-statistics 0.520 and 0.679).

CONCLUSION

Clinicians predicted mortality and MLLA revision well, but predicted morbidity poorly. They overestimated the risk of mortality, morbidity, and MLLA revision. Most short-term risk prediction tools had poorer discrimination or calibration than HCPs. The best method of predicting mortality was a statistical tool that incorporated HCP estimation.

Predictive Role of Aortic Valve Calcium score on post-procedural outcomes and mortality after Transcatheter aortic valve replacement

Introduction

Extent of aortic valve (AV) calcium increases as degenerative aortic valve stenosis progresses. Initial studies postulated AV calcium (AVC) score to be a predictor of complications such as need for pacemaker implantation, paravalvular regurgitation and mortality after Trans-catheter Aortic valve Replacement (TAVR). However, evidence regarding the impact of AVC score as a predictor of post-procedural complications and mortality has been conflicting.

Objective

This study aimed to determine the prognostic impact of AVC as predictor of post-procedural outcomes and mortality in patients with severe aortic stenosis (AS) who underwent TAVR.

Methods

We retrospectively abstracted the records of 497 patients with severe AS who underwent TAVR between January 2016 and July 2019 at our institution. All patients underwent a non-contrast cardiac CT scan on a Siemens Somatom Definition Flash 128 slice scanner. AVC score using the Agatston method was obtained retrospectively. Patients were divided into two groups: 1) Non-severe AVC score group [women <1200 Agatston unit (AU) and men <2000 AU]; 2) Severe AV Calcium Score group [women >1200 AU and men >2000 AU]. Primary outcome was 1-year mortality.

Results

Among 466 patients included in the analysis, 352 patients were included severe AVC group while 114 patients were in the non-severe AVC group. Patients in the severe AVC group were older (81±8 vs 79±8 years), were predominantly males (79% vs 71%), and had less diabetes mellitus (31% vs 42%, p=0.02). Post-TAVR AV dimensionless index (0.58±0.13 vs 0.58±0.12, p=0.8) and AV mean gradient (9.5±4.9 vs 9.2±5.4 mmHg) were not statistically different between both groups. There was no statistical difference in the need for PPM (12% vs 7%, p=0.16), post-TAVR stroke (1.5% vs 0%), post-TAVR major complications (17.4% vs 10%, p=0.07), 30 day (3.7% vs 4.4%), and 1-year mortality (13.6 vs 11.4, p=0.6) between both groups.

Conclusion

Our study report that the severity of AVC score does not have a prognostic impact on major post-procedural outcomes and mortality after TAVR.

Funding Acknowledgement

Type of funding sources: None.

Sex-based differences of the impact of aortic valve calcium score on mortality and post-procedural outcomes after trans-catheter aortic valve replacement

Introduction

Sex based differences exist in the presentation, outcomes, and management of cardiovascular diseases. Although aortic valve calcium (AVC) score has been postulated to be associated with post-procedural outcomes after transcatheter aortic valve replacement (TAVR), data on the impact of AVC score on procedural outcomes after TAVR based on sex have been scarce.

Objective

The aim of the present study was to elucidate sex related differences in the prognostic impact of AVC score as a predictor of post-procedural outcomes and mortality in patients with severe aortic stenosis (AS) who underwent TAVR.

Methods

We retrospectively abstracted the records of 497 patients with severe AS who underwent TAVR between January 2016 and July 2019 at our institution. All patients underwent a non-contrast cardiac CT scan on a Siemens Somatom Definition Flash 128 slice scanner. AVC score using the Agatston method was calculated retrospectively. Primary outcome was 1-year mortality. Patients were divided into two groups: 1) Non-severe AVC score group [women <1200 Agatston unit (AU) and men <2000 AU]; 2) Severe AVC Score group [women >1200 AU and men >2000 AU]. Cox-regression model was used to predict effect of variables on 1-year mortality in male and female patients.

Results

Among 466 patients included, 268 patients were male and 198 were female (57.5% vs 42.5%). When compared with males, female patients had significantly lower AVC score (p<0.001), aortic valve area (AVA) (p<0.001), obstructive CAD (p<0.001), and history of previous PCI (p<0.004), and CABG (<0.001) but had a significantly higher STS score (6.7±3.2 vs 5.8±3.3 P=0.01). There was no difference between need for permanent pacemaker (PPM) implantation (11% vs 9.6%, p=0.4), major complications (16% vs 15%, p=0.9), stroke (0.8% vs 1.6%, p=0.7), 30-day (3.7% vs 4%, p=0.9), and 1-year mortality (14% vs 12%, p=0.6) between males and females, respectively. Female patients required smaller bio-prosthetic valves compared with males (26±3.2 vs 30±3, p<0.001). Cox regression analysis for female patients showed BMI, hemoglobin level, and AVA independently predicted 1-year mortality, while there was no impact of severe AVC score (>1200 AU) on 1-year mortality in females. Similarly, Cox regression analysis for male patients showed there was no impact of severe AVC score (>2000 AU) on 1-year mortality in males. When males in the severe AVC group were compared with female patients in the severe AVC group, there was no difference in 30 day (4.3% vs 3.3%, p=0.82) and 1-year mortality (14.2% vs 13.3%, p=0.77). Similarly, in the severe AVC group there was no difference between need for PPM implantation (12.8% vs 12.1%, p=0.9), major complications (19.7% vs 15.8%, p=0.4), and stroke (2.2% vs 1%, p=0.6) between males and females, respectively.

Conclusion

There were no sex differences in the impact of AVC score on mortality and post-procedural outcomes after TAVR.

Funding Acknowledgement

Type of funding sources: None.

Accelerating model-informed decisions for COVID-19 vaccine candidates using a model-based meta-analysis approach

Background

The COVID-19 pandemic has increased the need for innovative quantitative decision tools to support rapid development of safe and efficacious vaccines against SARS-CoV-2. To meet that need, we developed and applied a model-based meta-analysis (MBMA) approach integrating non-clinical and clinical immunogenicity and protection data.

Methods

A systematic literature review identified studies of vaccines against SARS-CoV-2 in rhesus macaques (RM) and humans. Summary-level data of 13 RM and 8 clinical trials were used in the analysis. A RM MBMA model was developed to quantify the relationship between serum neutralizing (SN) titres after vaccination and peak viral load (VL) post-challenge in RM. The translation of the RM MBMA model to a clinical protection model was then carried out to predict clinical efficacies based on RM data alone. Subsequently, clinical SN and efficacy data were integrated to develop three predictive models of efficacy – a calibrated RM MBMA, a joint (RM-Clinical) MBMA, and the clinical MBMA model. The three models were leveraged to predict efficacies of vaccine candidates not included in the model and efficacies against newer strains of SARS-CoV-2.

Findings

Clinical efficacies predicted based on RM data alone were in reasonable agreement with the reported data. The SN titre predicted to provide 50% efficacy was estimated to be about 21% of the mean human convalescent titre level, and that value was consistent across the three models. Clinical efficacies predicted from the MBMA models agreed with reported efficacies for two vaccine candidates (BBV152 and CoronaVac) not included in the modelling and for efficacies against delta variant.

Interpretation

The three MBMA models are predictive of protection against SARS-CoV-2 and provide a translational framework to enable early Go/No-Go and study design decisions using non-clinical and/or limited clinical immunogenicity data in the development of novel SARS-CoV-2 vaccines.

Funding

This study was funded by Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

1010. Cross-Species Translation of Correlates of Protection for COVID-19 Vaccine Candidates Using Quantitative Tools

Background

Several COVID-19 vaccines have been authorized, and the need for rapid, further modification is anticipated. This work uses a Model-Based Meta-Analysis (MBMA) to relate, across species, immunogenicity to peak viral load (VL) after challenge and to clinical efficacy. Together with non-clinical and/or early clinical immunogenicity data (ECID), this enables prediction of a candidate vaccine’s clinical efficacy. The goal of this work was to enable the accelerated development of vaccine candidates by supporting Go/No-Go and study design decisions, and the resulting MBMA can be instrumental in decisions not to progress candidates to late stage development.

Methods

A literature review with pre-specified inclusion/exclusion criteria enabled creation of a database including nonclinical serum neutralizing titers (SN), peak VL after challenge with SARS-CoV-2 (VL), along with data from several clinical vaccine candidates. Rhesus Macaque (RM) and golden hamster (GH) were selected (due to availability and consistency of data) for MBMA modeling. For both RM and GH, peak post-challenge VL in lung and nasal tissues were used as surrogates for clinical disease and were related to pre-challenge SN via the MBMA. The VL predictions from the RM MBMA were scaled to incidence rates in humans, with a scaling factor between RM and human SN estimated using early Phase 3 efficacy data. This enabled clinical efficacy predictions based on ECID. To qualify the model’s predictive power, efficacies of COVID-19 vaccine candidates were compared to those predicted from the MBMA and their respective Ph1/2 SN data. More recently available clinical data enable building a clinical MBMA; comparing this to the RM MBMA further supports SN as predictive.

Results

The MBMA analyses identified a sigmoidal decrease in VL (increasing protection) with increase in SN in all three species, with more SN needed (in both RM and GH) for protection in nasal swabs than in BAL (see figure). The comparison between predicted and reported clinical efficacies demonstrated the model’s predictive power across vaccine platforms.

RM and GH MBMA Protection Models and Translational Prediction with Observed Efficacies

Sizes of circles indicate relative weight of the data in the respective quantitative model. Model and data visualizations have been harmonized (across tissue-types) separately for each of RM and GH using VACHER (Lommerse, et al., CPT:PSP, in press).

Conclusion

By quantifying adjustments needed between species and assays, translational MBMA can inform development decisions by using nonclinical SN and VL, and ECID to predict protection from COVID-19.

Disclosures

Anna Largajolli, PhD, Certara (Employee) Nele Plock, PhD, Certara (Employee, Shareholder)Merck & Co., Inc. (Independent Contractor) Bhargava Kandala, PhD, Merck & Co., Inc. (Employee, Shareholder) Akshita Chawla, PhD, Merck & Co., Inc. (Employee, Shareholder) Seth H. Robey, PhD, Merck & Co., Inc. (Employee, Shareholder) Kenny Watson, PhD, Certara (Employee, Shareholder) Raj Thatavarti, MS, Certara (Employee, Shareholder) Sheri Dubey, PhD, Merck & Co., Inc. (Employee, Shareholder) S. Y. Amy Cheung, PhD, Certara (Employee, Shareholder) Rik de Greef, MSc, Certara (Employee, Shareholder) Jeffrey R. Sachs, PhD, Merck & Co., Inc. (Employee, Shareholder)

1544 The Doctor Will Call You Now – Patients’ Perspective of The Implementation of Telephone Clinics in the COVID-19 Era

Aim

During the first wave of the COVID-19 pandemic, clinical guidelines advised the implementation of remote consultations with the aim of preventing viral transmission. Guidance included the introduction of telephone clinics and in March 2020, these were initiated for General Surgery at our rural DGH. The aim of this study was to review patients’ perspectives of these remote consultations.

Method

Using telephone clinic schedules, the first 100 patients of the telephone clinics were retrospectively identified. A survey was created using Google forms and questions covered patient demographics, as well as patients’ opinions on the organisation and efficacy of the clinic. The survey was completed via a telephone conversation with each patient between June to August 2020.

Results

72 patients consented to participate (age range: 24-80 years; 65% female). 44% of consultations were follow up, with 23% of patients having their initial appointment remotely. Although 82% of patients were able to discuss all concerns, nearly half of patients (43%) felt not having a face-to-face appointment affected their consultation. 78% of patients preferred remote consultations during the pandemic, but beyond this specific situation, 53% felt that in the future they would still prefer a face-to-face consultation. 57.6% of patients rated the newly implemented telephone consultations as 10/10.

Conclusions

The majority of patient feedback was positive. However, outside of the COVID-19 pandemic, our patients would prefer the traditional face-to-face consultation format. This outcome has been demonstrated in other similar studies worldwide, as it enables patients to be examined by and meet their surgeon prior to potential surgery.

Endodontic implications of a patient with arteriovenous malformation: a case report and literature review

AIM

To present the endodontic management of a patient diagnosed with a high-flow arteriovenous malformation (AVM) requiring root canal treatment and to discuss the relevant endodontic literature for this rare but significant problem.

SUMMARY

AVM is a complex communication of an artery and a vein in which the oxygenated blood is forced away from the intended tissue. The incidence of its occurrence in the face and neck is rare, and when present, the most common sign is gingival bleeding. Arteriovenous malformation is both a diagnostic and therapeutic challenge for dentists. Also, there is ambiguity regarding the precautions to be taken whilst doing endodontic procedures in such cases. Hence, there is a need to understand the disease process and its implications in order to prevent life-threatening complications during treatment. This case report highlights the successful endodontic management of a cariously exposed right maxillary second premolar in a patient diagnosed with high-flow AVM. On an orthopantomogram, the AVM was spreading in the left submandibular space involving the left ramus area. The clinical findings of limited mouth opening with inter-appointment swelling and trismus during treatment made the case unusual and challenging. This paper addresses the current understanding of the classification, diagnosis, clinical features and endodontic management, together with specific guidelines and recommendations whilst performing endodontic procedures in AVM cases.

KEY LEARNING POINTS

The classification and oral manifestations of AVM must be known and understood. Practitioners should be aware of the radiographic appearance of AVM. Recommended precautions should be taken when carrying out restorative and endodontic procedures in a patient with AVM. Antibiotic prophylaxis may be considered before endodontic treatment in a patient with AVM. Multidisciplinary treatment planning may be required.

Association between concentration of active MMP-9 in pulpal blood and pulpotomy outcome in permanent mature teeth with irreversible pulpitis - a preliminary study

AIM

To investigate the correlation between the concentration of active-matrix metalloproteinases-9 (aMMP-9) in pulpal blood and the outcome of pulpotomy in mature permanent teeth with symptomatic irreversible pulpitis (SIP).

METHODOLOGY

Forty permanent molar teeth with a clinical diagnosis of SIP and normal apical tissues with periapical index (PAI) score ≤ 2 and ten permanent teeth (8 molars and two premolars) with a diagnosis of normal pulp that required root canal treatment for prosthetic reasons from patients between the ages of 15-35 years were recruited. All clinical procedures were performed under local anaesthesia and rubber dam isolation. After access opening, the coronal pulp tissue was amputated up to the canal orifice. A 100 μL volume of the pulpal blood was collected using a micropipette and transported to the laboratory. Sodium hypochlorite (2.5 %) was used as a haemostatic agent, and mineral trioxide aggregate (MTA) was used as the pulp capping material. The tooth was restored with composite at the same visit. Teeth with normal pulps were treated with single-visit root canal treatment. Patients with pulpotomy were recalled at 6 and 12 months. Outcome assessment of teeth with pulpotomy was carried out at 12 months and was categorized as success (asymptomatic patients with PAI score ≤ 2) or failure (symptomatic patients or PAI score ≥ 3). Quantification of aMMP-9 in pulpal blood was achieved using a fluorometric assay. The following statistical analyses were performed to assess the data: t-test, Fisher's exact test, kappa coefficient, non-parametric test, Wilcoxon rank-sum test, Spearman rank correlation test and receiver operating characteristic curve (ROC).

RESULT

The success rate of pulpotomy was 88 % at 12-months. There was a significant difference between the median concentrations of aMMP-9 in pulpal blood of teeth with normal pulps (52 (12-96) ng mL^-1 :) and SIP (193.3 (25.8-607.7) ng mL^-1 :) (P = 0.0003) and successful (132.3 (25.8-548.3) ng mL^-1 :) and failed cases (512.4 (334.8-607.7 ng mL^-1 :) (P = 0.0015) of MTA pulpotomy. A significant association was established between aMMP-9 concentration and outcome of pulpotomy. The area under the receiver operating characteristics curve (0.9484, 95%CI) suggested excellent discriminatory power of aMMP-9 concentration in pulpal blood to predict the pulpotomy outcome.

CONCLUSION

The pulpal blood concentration of aMMP-9 was significantly associated with the outcome of pulpotomy in teeth with symptomatic irreversible pulpitis, where it may be used as a potential prognostic biomarker.

Safety and efficacy of superior calyceal access versus inferior calyceal access for pelvic and/or lower calyceal renal calculi- a prospective observational comparative study

Objective

To compare efficacy and safety between superior calyceal access and inferior calyceal access for pelvic and/or lower calyceal renal stones.

Methods

Consecutive patients presenting with Pelvic and/or inferior calyceal renal calculi were allocated to the superior calyceal access (group 1) or inferior calyceal access (group 2) treatment arm. Allocation of treatment access was based on the surgeon’s preference. Variables studied included stone free rate, operating time, intraoperative and postoperative complications. Statistical analysis was executed using SPSS, Version 16.0. The statistical significance was evaluated at 5% level of significance (p value < 0.05).

Results

Between July 2018 and February 2019, 63 patients were included in each group. The percutaneous inserted guidewire entered the ureter in 92% in group1 and 74.6% in group 2 (p = 0.034). Stone fragments migrated to the middle calyx in 3.2% in group1 and 9.5% in group 2 (p = 0.033). A second puncture was required in one patient in group 1 and in 5 patients in group 2 (p = 0.04). The operative duration (minutes) was 13.46 ± 1.09 in the group 1 while 16.58 ± 1.44 in the group 2 (p = 0.002). Thoracic complications (hydropneumothorax) occurred to 2 patients in superior calyceal access group managed with intercostal tube drainage (p = 0.243).Post operatively blood transfusion was required in two patients in group 2 (p = 0.169). Angioembolization was done in one patient among the inferior calyceal access approach (p = 0.683). Complete stone clearance assessed at 3 months was 96.8% in group 1 and 85.7% in group 2 (p = 0.046).

Conclusions

Superior calyceal access is a safe and most efficacious in terms of achieving complete stone clearance rate with reduced operative time, minimal blood loss, less need for a second puncture and auxiliary procedures at minimal complications.

Study registration

Clinical trials registry – INDIA; CTRI/2018/07/014,687.

International Nosocomial Infection Control Consortium (INICC) report, data summary of 45 countries for 2012-2017: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2012 to December 2017 in 523 intensive care units (ICUs) in 45 countries from Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, prospective data from 532,483 ICU patients hospitalized in 242 hospitals, for an aggregate of 2,197,304 patient days, were collected through the INICC Surveillance Online System (ISOS). The Centers for Disease Control and Prevention-National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI) were applied.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the medical-surgical ICUs, the pooled central line-associated bloodstream infection rate was higher (5.05 vs 0.8 per 1,000 central line-days); the ventilator-associated pneumonia rate was also higher (14.1 vs 0.9 per 1,000 ventilator-days,), as well as the rate of catheter-associated urinary tract infection (5.1 vs 1.7 per 1,000 catheter-days). From blood cultures samples, frequencies of resistance, such as of Pseudomonas aeruginosa to piperacillin-tazobactam (33.0% vs 18.3%), were also higher.

CONCLUSIONS

Despite a significant trend toward the reduction in INICC ICUs, DA-HAI rates are still much higher compared with CDC-NHSN's ICUs representing the developed world. It is INICC's main goal to provide basic and cost-effective resources, through the INICC Surveillance Online System to tackle the burden of DA-HAIs effectively.

The validity and reproducibility of cross table radiographs compared with CT scans for the measurement of anteversion of the acetabular component after total hip arthroplasty

Aims

The aim of this study was to assess the reproducibility and validity of cross table radiographs for measuring the anteversion of the acetabular component after total hip arthroplasty (THA) and to compare it with measurements using CT scans.

Patients and Methods

A total of 29 patients who underwent THA between June 2010 and January 2016 were included. There were 17 men and 12 women. Their mean age was 43 years (26 to 65). Seven patients underwent a bilateral procedure. Thus, 36 THAs were included in the study. Lateral radiographs and CT scans were obtained post-operatively and radiographs repeated three weeks later. The anteversion of the acetabular component was measured using the method described by Woo and Morrey and the ischiolateral method described by Pulos et al and these were compared with the results obtained from CT scans.

Results

The mean anteversion was 18.35° (3° to 38°) using Woo and Morrey’s method, 51.45° (30° to 85°) using the ischiolateral method and 21.22° (2° to 48°) using CT scans. The Pearson correlation coefficient was 0.754 for Woo and Morrey’s method and 0.925 for the ischiolateral method. There was a linear correlation between the measurements using the ischiolateral method and those using CT scans. We derived a simple linear equation between the value of the CT scan and that of ischiolateral method to deduce the CT scan value from that of ischiolateral method and vice versa.

Conclusion

The anteversion of the acetabular component measured using both plain radiographic methods was consistently valid with good interobserver reproducibility, but the ischiolateral method which is independent of pelvic tilt was more accurate. As CT is costly, associated with a high dose of radiation and not readily available, the ischiolateral method can be used for assessing the anteversion of the acetabular component. Cite this article: Bone Joint J 2017;99-B:1006–11.

Exploration of a new model of care in a psychiatry unit

The model established at Orillia Soldiers Memorial Hospital involves family physicians as the most responsible physician. They act as "admission gatekeeper" for all unattached patients who are admitted to the psychiatry in-patient unit. A PubMed, EBSCO, OVID Medline, Embase, CINAHL, and Web of Science database review of the last 10 years (2006-2016) was undertaken. A satisfaction survey was undertaken. An intensive literature review found this model to be unique. The model has proved to be extremely efficient and cost-effective.

International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs.

CONCLUSIONS

Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically.

Do Congenitally Blind Individuals have Better Haptic Object Perception Compared to Blindfolded Sighted Individuals?

Objective: Haptic perceptual enhancement in congenitally blind people is a subject of intense debate. There is no consensus whether the congenitally blind get the benefit of their haptic experience or the sighted get the benefit of previous visual experience when it comes to recognizing objects by manual exploration using different constraints. The present study compared haptic object perception between congenitally blind and blindfolded sighted participants in a situation where manual exploration of objects was constrained. Methods: Thirty congenitally blind braille readers and 30 age and gender matched controls were studied. All participants were required to identify the objects haptically, without the aid of vision. Manual exploration of the objects was constrained by permitting touching of the object with only the exposed tip of the index finger with the aim to limit cues about material information. Performance was evaluated in terms of speed and accuracy with which objects were identified. Result: The recognition time analysis showed that congenitally blind participants recognize objects much faster than blindfolded sighted participants. The analysis of haptic recognition rates showed that congenitally blind participants identified the objects more accurately compared to blindfolded normal sighted individuals. Conclusion: Congenitally blind individuals appear to possess a definite enhanced haptic perceptual ability allowing for faster and more accurate recognition of objects even when manual exploration is constrained.

Tell tale of tablets in bronchus

Foreign body (FB) aspiration is an emergency of concern at all ages. However, in adults, it can present with atypical symptoms such as shortness of breath, wheezing or rarely cyanosis. Aspiration of oral medications is seen in the elderly population with impairment of protective airway mechanism. Treatment of choice is endoscopic removal of the foreign body. We report such a case of foreign body aspiration (potassium chloride tablet), diagnosed on imaging and subsequently developed bronchostenosis. There are a very few reported cases of oral potassium supplement aspiration and associated complications in the literature.

Intravenous albumin infusion is an effective therapy for hyponatremia in patient with malignant ascites

There are few reports about the treatment of moderate to severe hyponatremia associated with malignant liver metastasis. Here, we report using intravenous salt poor albumin infusion to treat hypervolemic cirrhosis related hyponatremia. A 58-year-old female with ascites secondary to metastatic breast cancer was referred to our department with symptomatic hyponatremia (serum sodium concentration of 121 mEq/L). The serum sodium level was corrected slowly over 2 days with intravenous albumin infusion and the patient's symptoms – fatigue, nausea, dizziness and headache improved.

Patterns of adherence to NICE glaucoma guidance in two different service delivery models

PURPOSE

To assess adherence patterns to the UK National Institute of Health and Clinical Excellence (NICE) guidelines on glaucoma management (2009) in a tertiary referral centre shared care setting and in a district general hospital (DGH) setting.

METHOD

We performed a retrospective case note analysis of 200 patients from two centres between January and June 2010. The two centres involved were a consultant-guided teaching hospital optometry-led shared care setting (setting 1) and a consultant-led DGH clinic setting (setting 2). The main outcome measures were compliance with eight of the main NICE guidelines on glaucoma diagnosis and management (2009).

RESULTS

Both centres showed good adherence to the guidelines regarding the choice of initial treatment (96% vs 100%, settings 1 and 2, respectively) and arranging appropriate monitoring intervals (92% vs 86%). However, significant differences were seen when assessing whether an optic disc image was obtained at the initial visit (74% vs 10%), whether an appropriate initial assessment was performed (96% vs 58%), whether patients' review interval complied with the NICE guidance regardless of hospital cancellations (92% vs 66%), and whether concordance with medication was checked (88% vs 24%) (settings 1 and 2, respectively, P<0.01-Fisher's exact test).

CONCLUSION

Our study provides evidence to suggest that a hospital-based shared care service with trained optometrists using assessment sheets compares favourably to non-specialist glaucoma care delivered by ophthalmologists.

SU-E-I-77: X-Ray Coherent Scatter Diffraction Pattern Modeling in GEANT4

PURPOSE

To model X-ray coherent scatter diffraction patterns in GEANT4 for simulating experiments involving material detection through diffraction pattern measurement. Although coherent scatter cross-sections are modeled accurately in GEANT4, diffraction patterns for crystalline materials are not yet included. Here we describe our modeling of crystalline diffraction patterns in GEANT4 for specific materials and the validation of the results against experimentally measured data.

METHODS

Coherent scatter in GEANT4 is currently based on Hubbell's non-relativistic form factor tabulations from EPDL97. We modified the form-factors by introducing an interference function that accounts for the angular dependence between the Rayleigh-scattered photons and the photon wavelength. The modified form factors were used to replace the inherent form-factors in GEANT4. The simulation was tested using monochromatic and polychromatic x-ray beams (separately) incident on objects containing one or more elements with modified form-factors. The simulation results were compared against the experimentally measured diffraction images of corresponding objects using an in-house x-ray diffraction imager for validation. The comparison was made using the following metrics: number of diffraction rings, radial distance, absolute intensity, and relative intensity.

RESULTS

Sharp diffraction pattern rings were observed in the monochromatic simulations at locations consistent with the angular dependence of the photon wavelength. In the polychromatic simulations, the diffraction patterns exhibited a radial blur consistent with the energy spread of the polychromatic spectrum. The simulated and experimentally measured patterns showed identical numbers of rings with close agreement in radial distance, absolute and relative intensities (barring statistical fluctuations). No significant change was observed in the execution time of the simulations.

CONCLUSIONS

This work demonstrates the ability to model coherent scatter diffraction in GEANT4 in an accurate and efficient manner without compromising the accuracy or runtime of the simulation. This work was supported by the Department of Homeland Security under grant DHS (BAA 10-01 F075), and by the Department of Defense under award W81XWH-09-1-0066.

OXYGEN TOXICITY

Oxygen, the gas vital to sustain life, can also destroy it. It may become toxic at an elevated partial pressure, which may be the result of a rise in inspired oxygen concentration, an increase in environmental pressure or a combination of both. The toxicity tends to express itself most recognizably in one of several forms including central nervous system manifestations, pulmonary signs and symptoms and ocular effects, especially in premature infants. Other forms of toxicity should be expected in severe exposure but are difficult to detect and hence are not often considered important limitations for the use of oxygen. The onset and degree of the toxicity vary with the concentration of the gas used and the duration of exposure. Marked variations in individual susceptibility are found. Prevention of its occurrence and early detection of toxicity are called for, the treatment being symptomatic.