A novel method for quantification of cefazolin local tissue concentration in blood, fat, synovium, and bone marrow using liquid chromatography - mass spectrometry

To be effective, the concentration of antibiotic used must exceed the minimum inhibitory concentration (MIC) against infecting organisms at and in the surgical site. Few studies follow antibiotic levels for tissues that are manipulated during surgery. The aim of this work was to develop and validate a novel LC-MS method as well as an efficient extraction technique for the quantification of cefazolin in local tissues and whole blood. This method uses the same efficient extraction method across multiple tissue types affected by orthopedic surgery: blood, fat, synovium, and bone marrow. The ability to quantify cefazolin in these tissues will help identify surgical techniques and antibiotic dosing protocols that better protect patients from infection. The internal standard, 13C2,15N-cefazolin, co-elutes with cefazolin, and was used in calibration curves and tissue extracts as well as for cefazolin recovery and matrix effects. The protocol was rigorously tested, including measurements of reproducibility and calibration curve quality. The recovery of the extraction method ranges from 94% to 113% across all sample types. There is little to no matrix effect on cefazolin signal (98-120%). The developed method was used to determine cefazolin concentrations in tissues of 10 patients undergoing a total knee replacement. Cefazolin blood concentrations were approximately 500 times higher than in adipose, synovium, and bone marrow tissues. This clinical data shows that although the minimum inhibitory concentration is largely surpassed in blood, the concentration of cefazolin in fat, synovium, and bone marrow could be insufficient during a knee replacement. This method of cefazolin quantification will help surgeons optimize antibiotic concentrations in the local tissues during knee replacement surgery and potentially reduce serious post-surgical infections.

Cognitive dysfunction among patients referred for transcatheter aortic valve implantation: results of the Montreal Cognitive Assessment and clinical impact at 6 months

Background

Detection of Cognitive Dysfunction (CD) is not routinely performed among patients undergoing Transcatheter Aortic Valve Implantation (TAVI). We sought to determine whether CD has an impact on the clinical course of these patients, during hospitalization at the time of TAVI and up to 6 months afterwards.

Methods

The MoCA was performed before TAVI by an experienced operator in an unselected population of patients referred for TAVI. CD was defined according to the MoCA score: No CD if score ≥26, mild CD if score 18–25, moderate if 10–17 and severe if <10. Multivariate Cox logistic regression analysis was used to determine the impact of CD on procedural success of TAVI, length of stay, 6 month survival, re-admission, and change in clinical status (changes in NYHA class and/or functional status).

Results

MoCA was performed in 83 consecutive patients. TAVI was performed using femoral access and local anesthesia in all patients. There were no procedural deaths, and 2 deaths at 6 months. The median age was 85 years, and median Euroscore I was 11.62. The median MOCA score was 22, CD was excluded in 17 (20%), mild in 50 (60%), moderate in 15 (18%) and severe in one patient. No difference was observed in rate of procedural success, 6 month mortality, re-admission, degree of dyspnea by NYHA between the different cognitive groups. Length of stay after the TAVI procedure was lower in patients without CD, compared to those with CD at any level: 3±1 days versus 4.3±1 days, p=0.045, and p=0.02 by multivariate analysis (figure).

Conclusion

Among patients referred for TAVI, mild or moderate CD was observed in 80% of patients. Patients without CD had a shorter length of stay at the time of TAVI, but CD was not associated with worse prognosis or clinical status at 6 months.

Funding Acknowledgement

Type of funding sources: None.

Assessment of cognitive dysfunction using the Montreal Cognitive Assessment test: rate, severity and comparison with the Clock test alone in a population of patients referred for TAVI

Background

Although not recommended in routine practice, the detection and quantification of Cognitive Dysfunction (CD) in older patients might have an impact on clinical decisions. We assessed the rate and severity of CD in an unselected population of patients referred for Transcatheter Aortic Valve Implantation (TAVI) using the Montreal Cognitive Assessment (MoCA) and using the Clock Drawing Test (ClockT) alone.

Methods

The MoCA was performed before TAVI by an experienced operator. The ClockT was scored out of 10 points according to the Rouleau rating scale. CD was defined according to the MoCA score: No CD if score ≥26, mild CD if score 18–25, moderate if 10–17 and severe if <10. Inter-observer reliability of scoring on the ClockT was estimated with the Bland-Altman method. Agreement between MoCA scores and the ClockT for ruling out and for detecting CD were measured with the Kappa coefficient.

Results

MoCA was performed in 83 consecutive patients referred for TAVI, median age 85 years. The mean time required for assessment was 11±2 min for the MoCA and 3±2 min for the ClockT. The mean MoCA score was 21±4.5: CD was excluded in 17 (20%) pts, mild CD was found in 50 (60%), moderate in 15 (18%) and severe in one (1%). The median ClockT score was 8 (interquartile 6; 9), with excellent inter-observer concordance (Kappa= 0.84). Overall, 51% of the variance of the MoCA score was explained by the ClockT alone according to multiple regression. A ClockT <7 detected a group with significantly lower MoCA score, compared to pts with higher ClockT scores (figure).

Conclusion

Among patients referred for TAVI, CD can be excluded using the MoCA test in 20%, while moderate or severe CD is observed in 18%. The ClockT alone is faster to implement, reliable to interpret and enabled detection of patients with moderate CD when Rouleau scoring was <7.

Funding Acknowledgement

Type of funding sources: None.

Digital health technology for remote care in response to the COVID-19 pandemic: a scoping review

COVID-19 pandemic has forced the emergency deployment of digital health technology (DHT) to provide remote care. DHT is a promising option to enable telehealth, and, by the same token, it contributes to the implementation of social distance measures. The objective of this scoping review is to investigate existing DHT solutions that have been put in place to enable remote care in response to the COVID-19 pandemic. Structured literature searches were performed in Medline (Ovid), Scopus and CINAHL with Full Text (EBSCOhost), with a mix of keywords and controlled vocabulary unique to each database. The librarian utilized the search strategy on respiratory pandemics created in April 2020 for Medline (Ovid) by Canadian Agency for Drugs and Technology in Health (CADTH). An additional search for grey literature was performed including pre-prints and reports in Google Advanced, LitCovid and MedRx. Two independent reviewers assessed the articles retrieved from the databases (n=131) based on pre-established inclusion criteria and included six articles. Analysis of the results revealed six different types of DHT, including 5 dedicated to telemedicine and one used to track activity of people who were confined to their homes. The results showed positive health-related outcomes and user behavior outcomes. This review revealed that there is limited literature on the use of DHT to enable remote care in response to a pandemic and therefore calls for more documentation of the ongoing deployment of DHTs to support patient safety and the delivery of quality care during the COVID-19 pandemic and beyond.

[Self-evaluation of conization indications since the introduction of the French colposcopy and cervico-vaginal pathology quality charter in 2 colposcopy centers]

OBJECTIVES

Analyze the efficiency of the implementation of the colposcopy and cervico-vaginal pathology quality charter. The question was to determine whether the criteria of more than 70% of excisional conizations containing CIN2+ lesions (cervical intraepithelial neoplasia 2 or 3 or carcinoma in situ) had been reached and demonstrate a reduction of the conization rate is possible.

METHODS

An epidemiological descriptive, retrospective and multicenter study was performed in "Nord Franche-Comté Hospitals" (Belfort and Montbéliard, France) during the period from November 2013 to January 2015. Inclusion criteria were patients over 25 years undergoing cervical excisions for diagnostic and/or therapeutic purposes after Pap smear screening followed by colposcopically directed biopsies. The files were selected from a data collection and studied using the computerized patient record.

RESULTS

In total, 116 conizations were performed: 103 by four French Society of Colposcopy and Cervico-Vaginal Pathology (SFCPCV) members and 13 by four SFCPCV non-members. The overall result of the primary outcome showed 53% of CIN2+ lesions found in cervical conization specimens, which can be broken down to 55% for the group of SFCPCV members and to 38% for the group of SFCPCV non-members. The statistical analysis indicates a significant difference (P=0.02) in the percentage of CIN2+ lesions discovered on the surgical specimen for the group of SFCPCV members.

CONCLUSIONS

This self-evaluation shows that it is essential to be a SFCPCV member and to adhere to the charter. By complying with the charter and associating the new National Cancer Institute recommendations (December 2016), it is possible to reduce the conization rate and even to surpass the target of more than 70% of excisional conizations containing CIN2+ lesions.

Bilateral simultaneous metal inlay dissociation from the polyethylene liner of a metal-on-metal hip replacement

INTRODUCTION

Hard-on-hard bearings for total hip replacement may require a modular acetabular inlay for which polyethylene is often used in a sandwich-type configuration. However, differences in the elastic modulus of the materials make fixation of this metal insert uncertain. The aim of this study is to report a case of bilateral separation of the metal insert from the polyethylene sandwich in a metal-on-metal bearings prosthesis.

MATERIALS AND METHODS

A bilateral total hip arthroplasty was performed in two operations, four months apart, in a 53-year-old woman following a corticosteroid-induced osteonecrosis. The total hip replacement system included a cementless stem, and a press-fit hemispheric cup containing a polyethylene sandwich with a metallic insert (Sikomet).

RESULTS

Three years later, the patient consulted because of abnormal noise in her right hip which appeared normal on conventional X-ray. Three months later she consulted again for persistent noise. Separation of the metal insert from the polyethylene sandwich was diagnosed and an acetabular revision was performed selecting a metal-on-polyethylene articulation system. The postoperative course, for this revision, was uneventful, but the patient returned with the similar symptoms in her left hip four months later, resulting in the same type of revision. During the revisions, osteolysis secondary to metallosis was diagnosed, requiring synovectomy and acetabular reconstruction with morcelized allograft impaction. The left side postoperative course included three dislocations in nine months which were conservatively treated and have not since recurred.

DISCUSSION AND CONCLUSION

This is the first reported case recording an almost simultaneous bilateral dissociation of a hard-on-hard inlay from its polyethylene sandwich. This bilateral case suggests that the fixation of the metal insert inside the polyethylene was probably defective. This case is also a reminder that mechanical complications (separation, implant fracture) should be searched for in presence of any abnormal noise occurring after hard-on-hard bearings prosthetic implantation. This confirms the necessity of periodical follow-up of hip arthroplasties and the importance of knowing their radiological features. The low carbon content of the Sikomet bearing may have been the cause of this failure by increasing frictional torque on the bearing surface, causing metallosis which has already been described in the literature in this type of hip replacement system.