scholarly journals Efficacy of ventilator waveform observation for detection of patient–ventilator asynchrony during NIV: a multicentre study

2017 ◽  
Vol 3 (4) ◽  
pp. 00075-2017 ◽  
Author(s):  
Federico Longhini ◽  
Davide Colombo ◽  
Lara Pisani ◽  
Francesco Idone ◽  
Pan Chun ◽  
...  

The objective of this study was to assess ability to identify asynchronies during noninvasive ventilation (NIV) through ventilator waveforms according to experience and interface, and to ascertain the influence of breathing pattern and respiratory drive on sensitivity and prevalence of asynchronies.35 expert and 35 nonexpert physicians evaluated 40 5-min NIV reports displaying flow–time and airway pressure–time tracings; identified asynchronies were compared with those ascertained by three examiners who evaluated the same reports displaying, additionally, tracings of diaphragm electrical activity. We determined: 1) sensitivity, specificity, and positive and negative predictive values; 2) the correlation between the double true index (DTI) of each report (i.e., the ratio between the sum of true positives and true negatives, and the overall breath count) and the corresponding asynchrony index (AI); and 3) the influence of breathing pattern and respiratory drive on both AI and sensitivity.Sensitivities to detect asynchronies were low either according to experience (0.20 (95% CI 0.14–0.29) for expert versus 0.21 (95% CI 0.12–0.30) for nonexpert, p=0.837) or interface (0.28 (95% CI 0.17–0.37) for mask versus 0.10 (95% CI 0.05–0.16) for helmet, p<0.0001). DTI inversely correlated with the AI (r2=0.67, p<0.0001). Breathing pattern and respiratory drive did not affect prevalence of asynchronies and sensitivity.Patient–ventilator asynchrony during NIV is difficult to recognise solely by visual inspection of ventilator waveforms.

2021 ◽  
Vol 10 (19) ◽  
pp. 4550
Author(s):  
Bruno De Oliveira ◽  
Nahla Aljaberi ◽  
Ahmed Taha ◽  
Baraa Abduljawad ◽  
Fadi Hamed ◽  
...  

Patient–ventilator dyssynchrony is a mismatch between the patient’s respiratory efforts and mechanical ventilator delivery. Dyssynchrony can occur at any phase throughout the respiratory cycle. There are different types of dyssynchrony with different mechanisms and different potential management: trigger dyssynchrony (ineffective efforts, autotriggering, and double triggering); flow dyssynchrony, which happens during the inspiratory phase; and cycling dyssynchrony (premature cycling and delayed cycling). Dyssynchrony has been associated with patient outcomes. Thus, it is important to recognize and address these dyssynchronies at the bedside. Patient–ventilator dyssynchrony can be detected by carefully scrutinizing the airway pressure–time and flow–time waveforms displayed on the ventilator screens along with assessing the patient’s comfort. Clinicians need to know how to depict these dyssynchronies at the bedside. This review aims to define the different types of dyssynchrony and then discuss the evidence for their relationship with patient outcomes and address their potential management.


2022 ◽  
pp. emermed-2021-211823
Author(s):  
Keita Shibahashi ◽  
Kazuhiro Sugiyama ◽  
Takuto Ishida ◽  
Yuichi Hamabe

BackgroundThe duration from collapse to initiation of cardiopulmonary resuscitation (no-flow time) is one of the most important determinants of outcomes after out-of-hospital cardiac arrest (OHCA). Initial shockable cardiac rhythm (ventricular fibrillation or ventricular tachycardia) is reported to be a marker of short no-flow time; however, there is conflicting evidence regarding the impact of initial shockable cardiac rhythm on treatment decisions. We investigated the association between initial shockable cardiac rhythm and the no-flow time and evaluated whether initial shockable cardiac rhythm can be a marker of short no-flow time in patients with OHCA.MethodsPatients aged 18 years and older experiencing OHCA between 2010 and 2016 were selected from a nationwide population-based Japanese database. The association between the no-flow time duration and initial shockable cardiac rhythm was evaluated. Diagnostic accuracy was evaluated using the sensitivity, specificity and positive predictive value.ResultsA total of 177 634 patients were eligible for the analysis. The median age was 77 years (58.3%, men). Initial shockable cardiac rhythm was recorded in 11.8% of the patients. No-flow time duration was significantly associated with lower probability of initial shockable cardiac rhythm, with an adjusted OR of 0.97 (95% CI 0.96 to 0.97) per additional minute. The sensitivity, specificity and positive predictive value of initial shockable cardiac rhythm to identify a no-flow time of <5 min were 0.12 (95% CI 0.12 to 0.12), 0.88 (95% CI 0.88 to 0.89) and 0.35 (95% CI 0.34 to 0.35), respectively. The positive predictive values were 0.90, 0.95 and 0.99 with no-flow times of 15, 18 and 28 min, respectively.ConclusionsAlthough there was a significant association between initial shockable cardiac rhythm and no-flow time duration, initial shockable cardiac rhythm was not reliable when solely used as a surrogate of a short no-flow time duration after OHCA.


2005 ◽  
Vol 12 (3) ◽  
pp. 142-149 ◽  
Author(s):  
L O Sarian ◽  
S F Derchain ◽  
P Naud ◽  
C Roteli-Martins ◽  
A Longatto-Filho ◽  
...  

Objectives: To assess the performance indicators of visual inspection with acetic acid (VIA) and visual inspection with Lugol's iodine (VILI) in four Latin American centres participating in the ongoing Latin AMerican Screening (LAMS) study, in settings with moderate incidence of cervical disease and with poorly to moderately well-organized cervical cancer screening. Setting: Three Brazilian centres (São Paulo, Campinas and Porto Alegre) and one Argentine centre (Buenos Aires) recruited a total of 11,834 healthy women to undergo VIA, VILI, conventional Pap smear and Hybrid Capture II (HCII). Methods: Women who had a positive result from any of these tests were subjected to colposcopy and biopsies (if necessary), and women with high-grade cervical intraepithelial neoplasia (CIN) were properly treated. To control for verification bias, 5% of women with normal tests were referred for colposcopy, as were 20% of HCII-negative women. Results: Data on VIA ( n=11,834), VILI ( n=2994), conventional Pap smear ( n=10,138) and HCII ( n=4195) were available for test comparisons, calculating sensitivity, specificity, and positive and negative predictive values. Overall test positivity was 11.6% for VIA, 23.0% for VILI, 2.2% for Pap smear (LSIL threshold), 1.1% for Pap smear (HSIL threshold) and 17.1% for HCII. VIA was positive in 61.8% of the women with CIN 1, 57.0% of those with CIN 2, 35.0% of women with CIN 3 and in 21 of 28 (75%) of women with cancer. Approximately 10% of women with no detectable disease had an abnormal VIA. Regarding VILI, 83.3% of women diagnosed with CIN 1 and 62.5% of those with CIN 3 had an abnormal test. VILI failed to detect one of three cases of cancer. Both the sensitivity, specificity and positive predictive value of VIA and VILI in detecting CIN 2 or CIN 3 could be significantly improved depending on the combination with Pap smear or HCII (sensitivity up to 100.0% and specificity up to 99.8%). Conclusions: The LAMS study failed to reproduce the performance figures obtained with VIA and VILI (as stand-alone tests) in some other settings, where the prevalence of cervical disease was higher. However, a combined use of VIA or VILI with the Pap test or HCII allowed specific detection of cervical abnormalities.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
François Beloncle ◽  
Lise Piquilloud ◽  
Pierre-Yves Olivier ◽  
Alice Vuillermoz ◽  
Elise Yvin ◽  
...  

Abstract Background Occlusion pressure at 100 ms (P0.1), defined as the negative pressure measured 100 ms after the initiation of an inspiratory effort performed against a closed respiratory circuit, has been shown to be well correlated with central respiratory drive and respiratory effort. Automated P0.1 measurement is available on modern ventilators. However, the reliability of this measurement has never been studied. This bench study aimed at assessing the accuracy of P0.1 measurements automatically performed by different ICU ventilators. Methods Five ventilators set in pressure support mode were tested using a two-chamber test lung model simulating spontaneous breathing. P0.1 automatically displayed on the ventilator screen (P0.1vent) was recorded at three levels of simulated inspiratory effort corresponding to P0.1 of 2.5, 5 and 10 cm H2O measured directly at the test lung and considered as the reference values of P0.1 (P0.1ref). The pressure drop after 100 ms was measured offline on the airway pressure–time curves recorded during the automated P0.1 measurements (P0.1aw). P0.1vent was compared to P0.1ref and to P0.1aw. To assess the potential impact of the circuit length, P0.1 were also measured with circuits of different lengths (P0.1circuit). Results Variations of P0.1vent correlated well with variations of P0.1ref. Overall, P0.1vent underestimated P0.1ref except for the Löwenstein® ventilator at P0.1ref 2.5 cm H2O and for the Getinge group® ventilator at P0.1ref 10 cm H2O. The agreement between P0.1vent and P0.1ref assessed with the Bland–Altman method gave a mean bias of − 1.3 cm H2O (limits of agreement: 1 and − 3.7 cm H2O). Analysis of airway pressure–time and flow–time curves showed that all the tested ventilators except the Getinge group® ventilator performed an occlusion of at least 100 ms to measure P0.1. The agreement between P0.1vent and P0.1aw assessed with the Bland–Altman method gave a mean bias of 0.5 cm H2O (limits of agreement: 2.4 and − 1.4 cm H2O). The circuit’s length impacted P0.1 measurements’ values. A longer circuit was associated with lower P0.1circuit values. Conclusion P0.1vent relative changes are well correlated to P0.1ref changes in all the tested ventilators. Accuracy of absolute values of P0.1vent varies according to the ventilator model. Overall, P0.1vent underestimates P0.1ref. The length of the circuit may partially explain P0.1vent underestimation.


2018 ◽  
Vol 24 (S) ◽  
pp. 879-883
Author(s):  
Summera Aslam ◽  
Ahmed Zunair Wasim ◽  
Lubna Javed ◽  
Tayyiba Wasim

Objectives| To evaluate the accuracy of Visual Inspection with Acetic Acid (VIA) and Papanicolaou (Pap) smear as screening tests for cervical carcinoma and compare it with cervical biopsy as a gold standard. Methods| This was a cross-sectional study conducted at Gynae Unit 3 Services Institute of Medical Sciences from Jan 2016 to December 2016. All the married patients between 18 to 64 years of age were included in the study. Every patient underwent VIA, Pap smear and colposcopic directed biopsy from aceto white area as well as from 2:00 clock and 5:00 clock position. We determined the sensitivity, specificity, positive and negative predictive values of VIA, Pap smear and both tests and compared them with histopathology of biopsy specimen. Results| 476 women were screened in the study. Out of these, 110 (23.10%) patients were VIA positive and 40 (8.40%) patients were positive with Pap smear. Thirty seven (7.77%) patients were positive on both VIA and Pap smear. A total of 43 (9.03%) patients had cervical pre-malignancy on biopsy. The sensitivity of VIA and pap was 97.67%, 94.87% while specificity was 84.29% and 99.31%respectively (p=0.001). The PPV of VIA and pap was 38.18% and 92.5 %( p=0.00) while NPV was 99.7% and 99.5% respectively. The sensitivity and specificity of both tests combined was 94.59% and 99.54% while the PPV and NPV was 94.59% and 99.54% respectively. Diagnostic accuracy of VIA was 85.5%. Conclusion| VIA has high sensitivity and NPV which makes it an effective screening test for cervical carcinoma in developing countries like Pakistan. Pap smear can be combined to VIA positive cases to improve its specificity.


Author(s):  
Abinaya Maathuri Jeyakumar ◽  
Swarnalatha Mohanapu

Background: There are multiple screening methods available for screening cervical cancer with their advantages and disadvantages, researches that compare the sensitivity, specificity, positive and negative predictive values of these tests in a low-cost setting specific to a geographical area is lacking and has to be enhanced. The objective of this study was to determine and compare the agreement, sensitivity, specificity and predictive values of conventional Pap smear cytology, liquid-based cytology and VIA/VILI with cervix biopsy.Methods: This cross sectional study was conducted on women of >35 years of age. Pap smear specimen was collected followed by Liquid Base Cytology (LBC) using cytobrush specimen after which visual inspection with 5% acetic acid (VIA) and visual inspection with Lugol’s Iodine (VILI) procedure was carried out and followed by cervix biopsy. All methods were analyzed for accuracy.Results: Sensitivity was lowest for PAP smear (39.1%, 95% CI 19.18% to 59.1%), followed by VIA VILI (95.7%, 95% CI 87.32% to 100%), and highest for LBC (100.0%). The negative predictive value was lowest for PAP smear (87.4%, 95% CI 81.21% to 93.6%), followed by VIA VILI (99.0%, 95% CI 96.99% to 100.0%) and highest for LBC (100%). The overall diagnostic accuracy was lowest for PAP smear (88.3%) followed by VIA/VILLI (99.2%) and highest for LBC (100%).Conclusions: Treatment decisions based on findings of the PAP smear have to be taken with caution, considering the lower sensitivity. Wherever resources are available more accurate screening methods like liquid-based cytology must be used.


2003 ◽  
Vol 13 (5) ◽  
pp. 626-632 ◽  
Author(s):  
P. S. Basu ◽  
R. Sankaranarayanan ◽  
R. Mandal ◽  
C. Roy ◽  
P. Das ◽  
...  

Visual inspection of the cervix after application of 3–5% acetic acid (VIA) is a potential alternative to cytology for screening in low-resource countries. The present study evaluated the performance of VIA, magnified visual inspection after application of acetic acid (VIAM), and cytology in the detection of high-grade cervical cancer precursor lesions in Kolkata (Calcutta) and suburbs in eastern India. Trained health workers with college education concurrently screened 5881 women aged 30–64 years with VIA, VIAM, and conventional cervical cytology. Detection of well-defined, opaque acetowhite lesions close to the squamocolumnar junction; well-defined, circumorificial acetowhite lesions; or dense acetowhitening of ulceroproliferative growth on the cervix constituted a positive VIA or VIAM. Cytology was considered positive if reported as mild dysplasia or worse lesions. All screened women (N = 5881) were evaluated by colposcopy, and biopsies were directed in those with colposcopic abnormalities (N = 1052, 17.9%). The final diagnosis was based on histology (if biopsies had been taken) or colposcopic findings, which allowed direct estimation of sensitivity, specificity, and predictive values. Moderate or severe dysplasia or carcinoma in situ (CIN 2–3 disease) was considered as true positive disease for the calculation of sensitivity, specificity, and predictive values of screening tests. 18.7%, 17.7% and 8.2% of the women tested positive for VIA, VIAM, and cytology. One hundred twenty two women had a final diagnosis of CIN 2–3 lesions. The sensitivities of VIA and VIAM to detect CIN 2–3 lesions were 55.7% and 60.7%, respectively; the specificities were 82.1% and 83.2%, respectively. The sensitivity and specificity of cytology were 29.5% and 92.3%, respectively. All the tests were associated with negative predictive values above 98%. VIA and VIAM had significantly higher sensitivity than cytology in our study; the specificity of cytology was higher than that of VIA and VIAM.


2020 ◽  
Vol 163 (6) ◽  
pp. 1156-1165
Author(s):  
Juan Xiao ◽  
Qiang Xiao ◽  
Wei Cong ◽  
Ting Li ◽  
Shouluan Ding ◽  
...  

Objective To develop an easy-to-use nomogram for discrimination of malignant thyroid nodules and to compare diagnostic efficiency with the Kwak and American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS). Study Design Retrospective diagnostic study. Setting The Second Hospital of Shandong University. Subjects and Methods From March 2017 to April 2019, 792 patients with 1940 thyroid nodules were included into the training set; from May 2019 to December 2019, 174 patients with 389 nodules were included into the validation set. Multivariable logistic regression model was used to develop a nomogram for discriminating malignant nodules. To compare the diagnostic performance of the nomogram with the Kwak and ACR TI-RADS, the area under the receiver operating characteristic curve, sensitivity, specificity, and positive and negative predictive values were calculated. Results The nomogram consisted of 7 factors: composition, orientation, echogenicity, border, margin, extrathyroidal extension, and calcification. In the training set, for all nodules, the area under the curve (AUC) for the nomogram was 0.844, which was higher than the Kwak TI-RADS (0.826, P = .008) and the ACR TI-RADS (0.810, P < .001). For the 822 nodules >1 cm, the AUC of the nomogram was 0.891, which was higher than the Kwak TI-RADS (0.852, P < .001) and the ACR TI-RADS (0.853, P < .001). In the validation set, the AUC of the nomogram was also higher than the Kwak and ACR TI-RADS ( P < .05), each in the whole series and separately for nodules >1 or ≤1 cm. Conclusions When compared with the Kwak and ACR TI-RADS, the nomogram had a better performance in discriminating malignant thyroid nodules.


Author(s):  
Carmelo Saraniti ◽  
Enzo Chianetta ◽  
Giuseppe Greco ◽  
Norhafiza Mat Lazim ◽  
Barbara Verro

Introduction Narrow-band imaging is an endoscopic diagnostic tool that, focusing on superficial vascular changes, is useful to detect suspicious laryngeal lesions, enabling their complete excision with safe and tailored resection margins. Objectives To analyze the applications and benefits of narrow-band imaging in detecting premalignant and malignant laryngeal lesions through a comparison with white-light endoscopy. Data Synthesis A literature search was performed in the PubMed, Scopus and Web of Science databases using strict keywords. Then, two authors independently analyzed the articles, read the titles and abstracts, and read completely only the relevant studies according to certain eligibility criteria. In total, 14 articles have been included in the present review; the sensitivity, specificity, positive and negative predictive values, and accuracy of pre- and/or intraoperative narrow-band imaging were analyzed. The analysis showed that narrow-band imaging is better than white-light endoscopy in terms of sensitivity, specificity, positive and negative predictive values, and accuracy regarding the ability to identify cancer and/or precancerous laryngeal lesions. Moreover, the intraoperative performance of narrow-band imaging resulted more effective than the in-office performance. Conclusion Narrow-band imaging is an effective diagnostic tool to detect premalignant and malignant laryngeal lesions and to define proper resection margins. Moreover, narrow-band imaging is useful in cases of leukoplakia that may cover a possible malignant lesion and that cannot be easily assessed with white-light endoscopy. Finally, a shared, simple and practical classification of laryngeal lesions, such as that of the European Laryngological Society, is required to identify a shared lesion management strategy. Key Points


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