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The Journal of Applied Laboratory... May 2022Diagnostic sensitivities of point-of-care SARS-CoV-2 assays depend on specimen type and population-specific viral loads. Evaluation of these assays require "direct"...
BACKGROUND
Diagnostic sensitivities of point-of-care SARS-CoV-2 assays depend on specimen type and population-specific viral loads. Evaluation of these assays require "direct" specimens from paired-swab studies rather than more accessible residual specimens in viral transport media (VTM).
METHODS
Residual VTM and limit-of-detection studies were conducted on Abbott ID NOW™ COVID-19, Quidel Sofia 2™ SARS Antigen FIA, and DiaSorin Simplexa™ COVID-19 Direct assays, with cycle threshold (CT) adjustments to approximate direct-specimen testing based on gene-target doubling each PCR cycle. Logistic regression was used to model assay performance by specimen CT. These models were applied to CT distributions of symptomatic and asymptomatic populations presenting to emergency services to predict the percentage of specimens that would be detected by each assay. A 96-sample paired-swab study was conducted to confirm model results.
RESULTS
When using direct nasopharyngeal samples and fit with either VTM or limit-of-detection data, percent positivities for ID NOW (symptomatic 94.9%/97.4%; asymptomatic 88.4.0%/89.6%) and Simplexa (symptomatic 97.8%/97.2%; asymptomatic 91.1%/90.8%) were predicted to be similar. Likewise, percent positivities for ID NOW with direct nasal specimens (symptomatic 77.8%; asymptomatic 64.5%) and, fit with VTM data, Sofia 2 with direct nasopharyngeal specimens (symptomatic 76.6%, asymptomatic 60.3%) were similar. The paired-swab study comparing direct nasopharyngeal specimens on ID NOW and nasopharyngeal VTM specimens on Simplexa showed 99% concordance.
CONCLUSIONS
Assay performance can be modeled as dependent on viral load, fit using laboratory bench study results, and adjusted to account for direct-specimen testing. When using nasopharyngeal specimens, direct testing on Abbott ID NOW and VTM testing on DiaSorin Simplexa have similar performance.
Topics: COVID-19; COVID-19 Testing; Disease Progression; Humans; Nasopharynx; SARS-CoV-2; Sensitivity and Specificity
PubMed: 34755849
DOI: 10.1093/jalm/jfab159 -
Brazilian Dental Journal 2022This study evaluated the effect of surrounded shade and specimens` thickness on the color adjustment potential (CAP) of a single-shade composite. The composite Vittra...
This study evaluated the effect of surrounded shade and specimens` thickness on the color adjustment potential (CAP) of a single-shade composite. The composite Vittra APS Unique was surrounded (dual specimens) or not (simple specimens) by a control composite (shade A1, A2, or A3). Simple specimens of the control composite were also confectioned. Opacity and whiteness index for dentistry (WID) were calculated for simple specimens. Color differences between the simple (ΔE*SIMPLE)/ dual specimens (ΔE*DUAL) and the controls were calculated. CAP was calculated based on the ratio between ΔE* SIMPLE and ΔE* DUAL. The tested composite presented lower opacity (53 to 62% vs. 80 to 93%) and higher WID (≈ 42 vs. 18 to 32) than controls. Irrespective of the specimens' thickness (1.0/ 1.5 mm), the lowest values of ΔE* SIMPLE (11.1/ 10.8) and ΔE*DUAL (7.2/ 6.1) were observed using the surrounding shade A1. The shade A3 yielded higher ΔE*SIMPLE (16.4/ 17.1) and ΔE* DUAL (11.3/ 12.3) than the A2 (ΔE*SIMPLE = 13.4/ 14.6; and ΔE* DUAL = 9.7/ 10.3). The specimen`s thickness significantly affected the CAP (0.35 and 0.44 for 1.0 and 1.5 mm, respectively) only for shade A1, which had the highest CAP values. The shade A3 resulted in higher CAP values (0.31) than A2 (0.27) when 1.0-mm thick specimens were used, but similar values were observed for 1.5 thick specimens (≈ 0.29). In conclusion, both surrounding shade and specimen thickness can affect the CAP of a single-shade resin composite.
Topics: Color; Composite Resins; Materials Testing; Dental Porcelain
PubMed: 36287494
DOI: 10.1590/0103-6440202204973 -
Archives of Pathology & Laboratory... Feb 2020Preanalytic errors, including specimen labeling errors and specimen loss, occur frequently during specimen collection, transit, and accessioning. Radio-frequency...
CONTEXT.—
Preanalytic errors, including specimen labeling errors and specimen loss, occur frequently during specimen collection, transit, and accessioning. Radio-frequency identification tags can decrease specimen identification and tracking errors through continuous and automated tracking of specimens.
OBJECTIVE.—
To implement a specimen tracking infrastructure to reduce preanalytic errors (specimen mislabeling or loss) between specimen collection and laboratory accessioning. Specific goals were to decrease preanalytic errors by at least 70% and to simultaneously decrease employee effort dedicated to resolving preanalytic errors or investigating lost specimens.
DESIGN.—
A radio-frequency identification specimen-tracking system was developed. Major features included integral radio-frequency identification labels (radio-frequency identification tags and traditional bar codes in a single printed label) printed by point-of-care printers in collection suites; dispersed radio-frequency identification readers at major transit points; and systems integration of the electronic health record, laboratory information system, and radio-frequency identification tracking system to allow for computerized physician order entry driven label generation, specimen transit time tracking, interval-based alarms, and automated accessioning.
RESULTS.—
In the 6-month postimplementation period, 6 mislabeling events occurred in collection areas using the radio-frequency identification system, compared with 24 events in the 6-month preimplementation period (75% decrease; = .001). In addition, the system led to the timely recovery of 3 lost specimens. Labeling expenses were decreased substantially in the transition from high-frequency to ultrahigh frequency radio-frequency identification tags.
CONCLUSIONS.—
Radio-frequency identification specimen tracking prevented several potential specimen-loss events, decreased specimen recovery time, and decreased specimen labeling errors. Increases in labeling/tracking expenses for the system were more than offset by time savings and loss avoidance through error mitigation.
Topics: Humans; Medical Errors; Pathology, Clinical; Patient Identification Systems; Quality Assurance, Health Care; Specimen Handling
PubMed: 31246113
DOI: 10.5858/arpa.2019-0011-OA -
International Journal of Environmental... Jan 2022Sputum specimen referral cascades in resource-limited settings are characterized by losses of specimens, resulting in delays in tuberculosis (TB) diagnosis. Mpulungu...
Sputum specimen referral cascades in resource-limited settings are characterized by losses of specimens, resulting in delays in tuberculosis (TB) diagnosis. Mpulungu District Health Office in Zambia conducted a quantitative based cross-sectional study using both primary and secondary data to identify points at which loss of specimens occurred in the sputum referral cascade. Primary data were collected through observations and interviews with 22 TB service providers. Secondary data were collected through examination of patient files and presumptive TB and laboratory registers to retrospectively track sputum specimens referred by ten health centers from April to September 2018. Proportions of specimens/laboratory results at every stage of the referral cascade were calculated using Epi Info v7. Only 49 (23%) out of 209 sputum specimens completed the referral cascade. The remaining 160 (76%) were lost at various stages of the referral cascade. The largest loss (51%) occurred between the release of laboratory results by the diagnostic facility and their receipt at referring facilities. Barriers included an inadequate number of staff oriented in sputum specimen referral, negative staff attitudes, and lack of specimen packaging material and specimen transportation. The district health office should strengthen the sputum specimen referral system by providing transport and specimen packaging material and by training staff in sputum collection transportation and tracking.
Topics: Cross-Sectional Studies; Humans; Mycobacterium tuberculosis; Referral and Consultation; Retrospective Studies; Specimen Handling; Sputum; Zambia
PubMed: 35162643
DOI: 10.3390/ijerph19031621 -
American Journal of Respiratory and... Mar 2012Recent advances in therapy for non-small cell lung carcinoma have shown that a personalized approach to treatment has the potential to significantly reduce lung cancer... (Review)
Review
Recent advances in therapy for non-small cell lung carcinoma have shown that a personalized approach to treatment has the potential to significantly reduce lung cancer mortality. Concurrently, endoscopic ultrasound transbronchial needle aspiration has emerged as an accurate and sensitive tool for the diagnosis and staging of this disease. As knowledge of the molecular mechanisms that drive lung cancer progression increases, the amount of information that must be derived from a tumor specimen will also increase. Recent clinical studies have demonstrated that small specimens acquired by endoscopic ultrasound transbronchial needle aspiration are sufficient for molecular testing if specimen acquisition and processing are done with these needs in mind. Optimum use of this procedure requires a coordinated effort between the bronchoscopist and the cytopathologist to collect and triage specimens for diagnostic testing. When feasible, rapid onsite evaluation should be performed to assess the specimen for both diagnostic quality and quantity and to allocate the specimen for cell-block and possible immunohistochemistry and molecular studies. It is necessary for pulmonologists and bronchoscopists to understand the rationale for histologic and molecular testing of lung cancer diagnostic specimens and to ensure that specimens are acquired and processed in a fashion that provides information from small cytologic specimens that is sufficient to guide treatment in this era of targeted therapy.
Topics: Antineoplastic Agents; Biopsy, Needle; Bronchi; Bronchoscopy; Endosonography; Humans; Lung Neoplasms; Reproducibility of Results
PubMed: 22071327
DOI: 10.1164/rccm.201107-1199CI -
PloS One 2022Pre-analytical variables can have a significant adverse impact on the quality and credibility of coagulation test results. Therefore, correct and consistent...
BACKGROUND
Pre-analytical variables can have a significant adverse impact on the quality and credibility of coagulation test results. Therefore, correct and consistent identification of pre-analytical variables that compromise coagulation specimen quality is of paramount importance. Lack of standardization and heterogeneity among laboratory staff when assessing coagulation specimens can lead to inconsistent identification of these variables. Failure to recognize such pre-analytical variables results in the analysis of poor quality specimens and the authorization of spurious test results.
OBJECTIVES
To determine the impact of a laboratory staff training workshop on coagulation specimen rejection rates and to ascertain the level of knowledge of laboratory personnel concerning coagulation specimen rejection criteria before and after the workshop.
METHODS
A retrospective three-month audit was performed with rejection data of incorrect blood to additive ratio, clotted, aged and haemolysed specimens collected. Training workshops and evaluation sessions were subsequently presented. A revised standard operating procedure delineating coagulation specimen rejection criteria was implemented and a repeat three-month audit was conducted.
RESULTS
In total, 13 162 coagulation specimens were received during the initial audit with 1 104 specimens (8.39%) rejected. Following the workshops, the rejection rate increased by 3.49% to 11.88% with 12 743 coagulation specimens received and 1 514 specimens rejected. Evaluation sessions performed before and after the workshops revealed that 95.2% of attendees attained improved knowledge.
CONCLUSION
This study demonstrated the pivotal importance of regular laboratory staff training. The increase in specimen rejection following the workshops signifies their success in educating laboratory personnel regarding the correct identification of pre-analytical variables. Since most pre-analytical variables occur outside the laboratory, educational workshops need to be extended to non-laboratory personnel responsible for specimen collection and transport.
Topics: Aged; Blood Coagulation; Blood Specimen Collection; Humans; Laboratories; Retrospective Studies; Specimen Handling
PubMed: 35657929
DOI: 10.1371/journal.pone.0268764 -
BMC Surgery Jul 2021The last procedure performed by the surgeon in laparoscopic surgery is to extract the specimen through the smallest incision possible. This experiment aimed to explore...
BACKGROUND
The last procedure performed by the surgeon in laparoscopic surgery is to extract the specimen through the smallest incision possible. This experiment aimed to explore the maximum diameter of specimens that can be extracted through auxiliary incisions of different lengths and shapes by in vitro physical experiments.
MATERIALS AND METHODS
We used the abdominal wall with the muscle layer, fixed on a square wooden frame, to simulate the human abdominal wall. Then, specimen extraction ports were made with circular, inverted Y-shaped and straight-line incisions of different sizes and lengths, and specimens of different sizes were made from tissues of different species. These specimens were extracted from different incisions with a force gauge. The tension value (N) was measured, and records were made of the length or diameter of the smallest auxiliary incision through which a given specimen could pass, as well as the largest specimen diameter that could pass through an incision of a given size. This experiment provides us with preliminary experience-based knowledge of how to choose the appropriate auxiliary incision for surgical specimen extraction according to the diameter of the specimen.
RESULTS
The maximum diameters of specimens that could be extracted with circular ostomy diameters of 2.4, 2.7 and 3.3 cm were 4.0, 4.5 and 6.0 cm, respectively. Specimens with diameters of 6.0, 8.0 and 10.0 cm could be extracted through inverted Y-shaped incisions with a length around the umbilicus of 1 cm and an extension length of 1.0, 3.0, and 4.0 cm, respectively. Moreover, these same specimens could be extracted through inverted Y-shaped incisions with a length around the umbilicus of 2 cm and extension lengths of 0.0, 1.0 and 2.0 cm. Tough tissue specimens (made from chicken gizzards) with diameters of 1.0, 2.0, 4.0 and 6.0 cm, respectively, could be removed through straight-line incisions measuring 1.0, 2.0, 3.0 and 4.0 cm in length.
CONCLUSION
Along with preoperative imaging, surgical planning and trocar position, the shape and length of auxiliary incisions can be used to improve the extraction of specimens via laparoscopic surgery.
Topics: Humans; Laparoscopy; Surgical Instruments; Surgical Wound; Umbilicus
PubMed: 34210315
DOI: 10.1186/s12893-021-01300-5 -
Obstetrics & Gynecology Science May 2022Transvaginal removal of large specimens during laparoscopic hysterectomy can be a complex surgical procedure that poses a risk of organ injury and tissue spillage into...
OBJECTIVE
Transvaginal removal of large specimens during laparoscopic hysterectomy can be a complex surgical procedure that poses a risk of organ injury and tissue spillage into the abdominal cavity and is associated with extraction of the specimen and manual morcellation. Our objective was to demonstrate a technique for transvaginal removal of large specimens using the Alexis Contained Extraction System (CES) in laparoscopic hysterectomy.
METHODS
The technique used for transvaginal removal of large specimens using the Alexis CES was presented in this video. Surgery was performed at a tertiary hospital.
RESULTS
Following resection of the specimen during laparoscopic hysterectomy, the Alexis CES was inserted into the abdominal cavity through the umbilical trocar wound. The specimen was placed in a bag to prevent tissue spillage. The ring retractor was guided to the vagina and pulled out transvaginally. By repeatedly turning the ring retractor, tension was applied to the specimen bag, and the vaginal wall was unfolded all around to enable a secure surgical field. During manual morcellation of the specimen in the bag, the retractor was pulled and additionally turned to roll and re-tension the specimen bag when the bag was loosened. The specimen was pushed out of the vagina and safely and effectively extracted without concerns about tissue spillage in the abdominal cavity or related organ injuries.
CONCLUSION
The technique for transvaginal removal of large specimens using the Alexis CES enables simple, effective, and safe tissue extraction with contained manual morcellation during laparoscopic hysterectomy.
PubMed: 35081674
DOI: 10.5468/ogs.21358 -
Langenbeck's Archives of Surgery Dec 2022The choice for an ideal site of specimen extraction following laparoscopic colorectal surgery remains debatable. However, midline incision (MI) is usually employed for...
BACKGROUND
The choice for an ideal site of specimen extraction following laparoscopic colorectal surgery remains debatable. However, midline incision (MI) is usually employed for right and left-sided colonic resections while left iliac fossa or suprapubic transverse incision (STI) were reserved for sigmoid and rectal cancer resections.
OBJECTIVE
To compare the incidence of surgical site infection (SSI) and incisional hernia (IH) in elective laparoscopic colorectal surgery for cancer and specimen extraction via MI or STI.
METHOD
Prospectively collected data of elective laparoscopic colorectal cancer resections between January 2017 and December 2019 were retrospectively reviewed. MI was employed for right and left-sided colonic resections while STI was used for sigmoid and rectal resections. SSI is defined according to the US CDC criteria. IH was diagnosed clinically and confirmed by CT scan at 1 year.
RESULTS
A total of 168 patients underwent elective laparoscopic colorectal resections. MI was used in 90 patients while 78 patients had STI as an extraction site. Demographic and preoperative data is similar for two groups. The rate of IH was 13.3% for MI and 0% in the STI (p = 0.001). SSI was seen in 16.7% of MI vs 11.5% of STI (p = 0.34). Univariate and multivariate analysis showed that the choice of extraction site is associated with statistically significant higher incisional hernia rate.
CONCLUSION
MI for specimen extraction is associated with higher incidence of both SSI and IH. The choice of incision for extraction site is an independent predicative factor for significantly higher IH and increased SSI rates.
Topics: Humans; Incisional Hernia; Colectomy; Retrospective Studies; Risk Factors; Laparoscopy; Surgical Wound Infection; Morbidity; Colorectal Neoplasms
PubMed: 36219253
DOI: 10.1007/s00423-022-02701-7 -
Biochemia Medica Oct 2018Specimen adequacy is a crucial preanalytical factor affecting accuracy and usefulness of test result. The aim of this study was to determine the frequency and reasons...
INTRODUCTION
Specimen adequacy is a crucial preanalytical factor affecting accuracy and usefulness of test result. The aim of this study was to determine the frequency and reasons for rejected haematology specimens, preanalytical variables which may affect specimen quality, and consequences of rejection, and provide suggestions on monitoring quality indicators as to obtain a quality improvement.
MATERIALS AND METHODS
A cross-sectional survey was conducted and a questionnaire was sent to 1586 laboratories. Participants were asked to provide general information about institution and practices on specimen management and record rejections and reasons for rejection from 1 to 31 July.
RESULTS
A total survey response rate was 56% (890/1586). Of 10,181,036 tubes received during the data collection period, 11,447 (0.11%) were rejected, and the sigma (σ) was 4.6. The main reason for unacceptable specimens was clotted specimen (57%). Rejected specimens were related to source department, container type, container material type, transportation method and phlebotomy personnel. The recollection of 84% of the rejected specimens was required. The median specimen processing delay in inpatient, outpatient and emergency department were 81.0 minutes, 57.0 minutes and 43.3 minutes, respectively.
CONCLUSIONS
Overall, rejection rate was a slightly lower than previously published data. In order to achieve a better quality in the preanalytical phase, haematology laboratories in China should pay more attention on training for phlebotomy and sample transportation, identify main reasons for clotted specimen and take effective measures. The platform in the study will be helpful for long-term monitoring, but simplification and modification should be introduced in the following investigation.
Topics: China; Hematologic Tests; Humans; Laboratories; Quality Control; Surveys and Questionnaires
PubMed: 30429672
DOI: 10.11613/BM.2018.030704