Relationship between pulse pressure variation and stroke volume variation with changes in cardiac index during hypotension in patients undergoing major spine surgeries in prone position - A prospective observational study

Background and Aims

Dynamic indices such as pulse pressure variation (PPV) and stroke volume variation (SVV) are better predictors of fluid responsiveness than static indices. There is a strong correlation between PPV and SVV in the prone position when assessed with the fluid challenge. However, this correlation has not been established during intraoperative hypotension. Our study aimed to assess the correlation between PPV and SVV during hypotension in the prone position and its relationship with cardiac index (CI).

Material and Methods

Thirty patients aged 18-70 years of ASA class I-III, undergoing spine procedures in the prone position were recruited for this prospective observational study. Hemodynamic variables such as heart rate (HR), mean arterial pressure (MAP), PPV, SVV, and CI were measured at baseline (after induction of anesthesia and positioning in the prone position). This set of variables were collected at the time of hypotension (T-before) and after correction (T-after) with either fluids or vasopressors. HR and MAP are presented as median with inter quartile range and compared by Mann-Whitney U test. Reliability was measured by intraclass correlation coefficients (ICC). Generalized estimating equations were performed to assess the change of CI with changes in PPV and SVV.

Results

A statistically significant linear relationship between PPV and SVV was observed. The ICC between change in PPV and SVV during hypotension was 0.9143, and after the intervention was 0.9091 (P < 0.001). Regression of changes in PPV and SVV on changes in CI depicted the reciprocal change in CI which was not statistically significant.

Conclusion

PPV is a reliable surrogate of SVV during intraoperative hypotension in the prone position.

Framework for Machine Learning of CT and PET Radiomics to Predict Local Failure after Radiotherapy in Locally Advanced Head and Neck Cancers

Context:

Cancer Radiomics is an emerging field in medical imaging and refers to the process of converting routine radiological images that are typically qualitatively interpreted to quantifiable descriptions of the tumor phenotypes and when combined with statistical analytics can improve the accuracy of clinical outcome prediction models. However, to understand the radiomic features and their correlation to molecular changes in the tumor, first, there is a need for the development of robust image analysis methods, software tools and statistical prediction models which is often limited in low- and middle-income countries (LMIC).

Aims:

The aim is to build a framework for machine learning of radiomic features of planning computed tomography (CT) and positron emission tomography (PET) using open source radiomics and data analytics platforms to make it widely accessible to clinical groups. The framework is tested in a small cohort to predict local disease failure following radiation treatment for head-and-neck cancer (HNC). The predictors were also compared with the existing Aerts HNC radiomics signature.

Settings and Design:

Retrospective analysis of patients with locally advanced HNC between 2017 and 2018 and 31 patients with both pre- and post-radiation CT and evaluation PET were selected.

Subjects and Methods:

Tumor volumes were delineated on baseline PET using the semi-automatic adaptive-threshold algorithm and propagated to CT; PyRadiomics features (total of 110 under shape/intensity/texture classes) were extracted. Two feature-selection methods were tested for model stability. Models were built based on least absolute shrinkage and selection operator-logistic and Ridge regression of the top pretreatment radiomic features and compared to Aerts' HNC-signature. Average model performance across all internal validation test folds was summarized by the area under the receiver operator curve (ROC).

Results:

Both feature selection methods selected CT features MCC (GLCM), SumEntropy (GLCM) and Sphericity (Shape) that could predict the binary failure status in the cross-validated group and achieved an AUC >0.7. However, models using Aerts' signature features (Energy, Compactness, GLRLM-GrayLevelNonUniformity and GrayLevelNonUniformity-HLH wavelet) could not achieve a clear separation between outcomes (AUC = 0.51–0.54).

Conclusions:

Radiomics pipeline included open-source workflows which makes it adoptable in LMIC countries. Additional independent validation of data is crucial for the implementation of radiomic models for clinical risk stratification.

Impact of COVID-19 pandemic on income and opportunities of ophthalmologists in India: Ophthalmologists' Workplace Expectations and Satisfaction Survey (OWESS) Report 1

Purpose

To evaluate the impact of COVID-19 pandemic on the income and surgical training opportunities among the ophthalmologists in India and their opinion on salary reduction during this period.

Methods

A questionnaire in the form of a Google survey was sent to ophthalmologists across India on May 1, 2021. The data collected until May 11, 2021 was analyzed.

Results

A total of 1057 ophthalmologists all over India participated in the survey. Of the respondents, 559 (52.9%) were women and 730 (69.1%) were young ophthalmologists (below the age of 40 years). Salary reduction was reported by 569 (53.8%) of the respondents. The categories suffering the maximum salary reduction were - young ophthalmologists (407, 55.8%) (P < 0.001), women (304, 54.4%) (P < 0.001), and private sector employees (457, 67%) (P < 0.001). More women ophthalmologists (438, 78.4%) felt it was unfair to reduce the salary during the pandemic, as compared to men (330, 66.3%) (P < 0.001). A reduction in surgical training opportunities was reported by 689 (65.2%) of ophthalmologists. The categories who suffered the maximum loss of surgical training opportunities were young ophthalmologists (565, 77.4%) (P < 0.001), women ophthalmologists (415, 74.2%) (P < 0.001), and ophthalmologists in the government sector (147, 82.6%) (P < 0.001).

Conclusion

Ophthalmologists in India, especially women and the younger professionals, had to face salary reduction and loss of surgical training opportunities during the COVID-19 pandemic. Most ophthalmologists in India do not favor a reduction in salary. There is a need to formulate policies to safeguard ophthalmologists, especially women and younger generation from future crises in training, employment, and income.

Rodenticide ingestion is an important cause of acute hepatotoxicity in Tamil Nadu, southern India

BACKGROUND AND AIM

Though rodenticidal hepatotoxicity is reported from India, there is no systematic study to assess its magnitude. This study aimed to assess exposure to rodenticide as a risk factor for acute hepatotoxicity in Tamil Nadu, India.

METHODS

We retrospectively analyzed acute hepatotoxicity caused by ingestion of hepatotoxin or potentially hepatotoxic drug overdose across 15 hospitals in 6 districts of Tamil Nadu from 1 January 2019 to 30 June 2019. Study exclusion criteria were idiosyncratic drug-induced liver injury and chronic liver diseases.

RESULTS

Of the 702 patients, 685 gave history of consuming rodenticide; hepatotoxicity in the other patients resulted from paracetamol overdose (n=10) and due to other drugs (n=7); 97% patients had a suicidal intent. Of 671 patients with complete data, ratio of number of patients with hepatotoxicity due to rodenticide to paracetamol overdose was 450:6 (i.e. 75:1). The 451 rodenticidal hepatotoxicity patients (255 males, 75% were 15-34 years old) underwent conservative management (n=396), plasma exchange (n=54) and plasma exchange followed by liver transplant (n=1); 159 patients (35%) had poor outcome (131 died, 28 discharged in moribund state). Based on our observations, we estimate a case burden of 1584 rodenticidal hepatotoxicity patients (95% CI: 265-6119) with poor outcome in 554 patients in Tamil Nadu from January 2019 to June 2019. Population attributable risk for rodenticide as cause of hepatotoxicity was 22.7%.

CONCLUSION

Rodenticide ingestion was an important cause of acute hepatotoxicity in Tamil Nadu. Most patients were young and one-third had poor outcome. Public health interventions are needed to address this.

Plasma Von Willebrand Factor Levels Predict Survival in COVID-19 Patients Across the Entire Spectrum of Disease Severity

Background: Characterization of reticulo-endothelial activation in COVID-19 may guide treatment. Objectives: To assess reticulo-endothelial activation and its correlation with disease severity and death in patients across the entire spectrum of COVID-19 severity. Methods: Consecutive hospitalized COVID-19 patients were studied, with similar number of patients in each disease severity category. Baseline serum ferritin, sCD163 (macrophage activation markers) and plasma von Willebrand factor (VWF) antigen (endothelial activation marker) levels were studied. Clinical parameters and plasma D-dimer levels were also studied. The study parameters were correlated with COVID-19 severity and survival. Results: The 143 patients (104 males [80%], age 54 [42 – 65] years, median [inter-quartile range]) presented 4 (3—7) days after symptom onset. Thirty-four patients had mild disease, 36 had moderate disease, 36 had severe disease and 37 had critical disease at baseline. With increasing COVID-19 severity, ferritin, sCD163, VWF and D-dimer levels significantly increased at baseline, however, 139 patients had normal sCD163 levels. Of the reticulo-endothelial markers, VWF level independently correlated with COVID-19 severity and with survival. VWF level > 332.6 units/dl correlated with COVID-19 severity (odds ratio [OR]: 2.77 [95% confidence interval (C.I): 1.1 – 6.99], p value: 0.031) and in-hospital death (OR [95% CI]: 29.28 [5.2 – 165], p value < 0.001). Conclusions: Reticulo-endothelial activation markers increased incrementally with worsening COVID-19 severity. Baseline endothelial activation marker (VWF), and not macrophage activation markers, independently correlated with COVID-19 severity and death.

Cotrimoxazole prophylaxis prevents major infective episodes in patients with systemic lupus erythematosus on immunosuppressants: A non-concurrent cohort study

BACKGROUND

Prophylactic trimethoprim-sulfamethoxazole (TMP-SMX) prevents pneumocystis jirovecii infection in SLE on immunosuppression. Its role in preventing other major infections in immuno suppressed SLE patients is unknown.

METHODS

A non-concurrent cohort study was conducted on patients of SLE fulfilling SLICC and/or ACR 1997 criteria, who received tapering dose of steroid starting with ≥0.5 mg/kg/day of prednisolone or equivalent dose of deflazacort and mycophenolate mofetil ≥1 g/day (or equivalent dose of mycophenolate sodium) at least for the preceding 1 year. Interviewing patients & documenting relevant data from hospital electronic Medical records (EMR), followed by comparison of Incidence densities of major infections between those on prophylactic Trimethoprim 160 mg + Sulfamethoxazole 800 mg and those not on it, was done by student 't' test. Multivariate logistic regression was performed for independent risk of any major infection between the two groups.

RESULTS

Of 228 patients, 162 did not receive TMP-SMX prophylaxis, and 66 had received. The incidence density of major infection was found to be significantly lower in TMP-SMX group (1.25 per 100 person year) as compared to those not on TMP-SMX group (11.201 per 100 person year); P < 0.001 (95% CI 0.027 - 0.449) and odds ratio of 0.03 (CI 0 - 0.24).

CONCLUSION

Cotrimoxazole prophylaxis in SLE patients on immunosuppression prevents major infections.

A validated audio-visual educational module on examination skills in ophthalmology for undergraduate medical students in the COVID-19 season - An observational longitudinal study

Purpose

The aim of this study was to assess the impact of an audio visual (AV) teaching module on basic torchlight examination of the eye and direct ophthalmoscopy for undergraduate medical students.

Methods

This observational longitudinal study was done on 33 consecutive medical interns during their Ophthalmology posting from December 2019 to March 2020 at a medical college in South-India. An AV-module was created using animation graphics, narratives, demonstrations on normal individuals and on patients with positive signs. All interns had a pretest consisting of Multiple-choice questions, (MCQs) and an Objective Structured Clinical Examination (OSCE) on torchlight examination and direct ophthalmoscopy (DO). They were then shown the 20-minute AV-module. A posttest was performed immediately and after one week.

Results

The mean pretest MCQ score was 5.84 ± 1.98. It improved to 8.81 ± 1.15 in the immediate posttest and 8.87 ± 1.66 in the one-week posttest. The mean pretest OSCE score was 12.21 ± 3.39. It improved to 23.21 ± 3.39 in the immediate posttest and 23.90 ± 3.7 in the one-week posttest. Using Generalized Estimating Equation, MCQ score improved by 2.97 units and 3.03 units and the OSCE score improved by 11 units and 11.69 units in the immediate posttest and one-week posttest respectively when compared to the pretest corresponding to the MCQ score and OSCE score (p < 0.001).

Conclusion

AV teaching modules-for torchlight examination and DO has a significant benefit in improving knowledge and skill in undergraduate medical students. These significant results have the great translatory capacity in the current COVID-19 pandemic, where physical demonstrations involving close proximity and groups of students are highly risk prone.

Modelling of reproduction number for COVID-19 in India and high incidence states

Background

Since the onset of the COVID-19 in China, forecasting and projections of the epidemic based on epidemiological models have been in the centre stage. Researchers have used various models to predict the maximum extent of the number of cases and the time of peak. This yielded varying numbers. This paper aims to estimate the effective reproduction number (R) for COVID-19 over time using incident number of cases that are reported by the government.

Methods

Exponential Growth method to estimate basic reproduction rate R₀, and Time dependent method to calculate the effective reproduction number (dynamic) were used. "R0" package in R software was used to estimate these statistics.

Results

The basic reproduction number (R₀) for India was estimated at 1.379 (95% CI: 1.375, 1.384). This was 1.450 (1.441, 1.460) for Maharashtra, 1.444 (1.430, 1.460) for Gujarat, 1.297 (1.284, 1.310) for Delhi and 1.405 (1.389, 1.421) for Tamil Nadu. In India, the R at the first week from March 2-8, 2020 was 3.2. It remained around 2 units for three weeks, from March 9-29, 2020. After March 2020, it started declining and reached around 1.3 in the following week suggesting a stabilisation of the transmissibility rate.

Conclusion

The study estimated a baseline R₀ of 1.379 for India. It also showed that the R was getting stabilised from first week of April (with an average R of 1.29), despite the increase in March. This suggested that in due course there will be a reversal of epidemic. However, these analyses should be revised periodically.

Forecasting COVID-19 epidemic in India and high incidence states using SIR and logistic growth models

Background

Ever since the Coronavirus disease (COVID-19) outbreak emerged in China, there has been several attempts to predict the epidemic across the world with varying degrees of accuracy and reliability. This paper aims to carry out a short-term projection of new cases; forecast the maximum number of active cases for India and selected high-incidence states; and evaluate the impact of three weeks lock down period using different models.

Methods

We used Logistic growth curve model for short term prediction; SIR models to forecast the maximum number of active cases and peak time; and Time Interrupted Regression model to evaluate the impact of lockdown and other interventions.

Results

The predicted cumulative number of cases for India was 58,912 (95% CI: 57,960, 59,853) by May 08, 2020 and the observed number of cases was 59,695. The model predicts a cumulative number of 1,02,974 (95% CI: 1,01,987, 1,03,904) cases by May 22, 2020. As per SIR model, the maximum number of active cases is projected to be 57,449 on May 18, 2020. The time interrupted regression model indicates a decrease of about 149 daily new cases after the lock down period, which is statistically not significant.

Conclusion

The Logistic growth curve model predicts accurately the short-term scenario for India and high incidence states. The prediction through SIR model may be used for planning and prepare the health systems. The study also suggests that there is no evidence to conclude that there is a positive impact of lockdown in terms of reduction in new cases.

Predictors of mortality, strategies to reduce readmission, and economic impact of acute decompensated heart failure: Results of the Vellore Heart Failure Registry

AIM

Heart failure is a global problem that is increasing in prevalence. We undertook the initiative to compile the Vellore Heart Failure Registry (VHFR) to assess the clinical profile, mortality, risk factors and economic burden of heart failure by conducting a prospective, observational, hospital-based cohort study in Vellore, Tamil Nadu.

METHODS AND RESULTS

This study was a prospective observational cohort study conducted at the Christian Medical College and Hospital, Vellore, between January 2014 and December 2016. A total of 572 patients who satisfied the Boston criteria for "definite heart failure" were included and the primary outcome was all-cause mortality. The median duration of hospital stay was eight days and the in-hospital, one, three and six month mortalities were 13.25%, 27.3%, 32.53% and 38.15%, respectively. The median duration of survival was 921 days. Readmission for heart failure constituted 42%, and the most common cause of decompensation was an infection(31.5%). The presence of cyanosis at admission, history of previous stroke or transient ischemic attack, and American College of Cardiology (ACC)/American Heart Association (AHA) stage D at the time of discharge were independently associated with mortality at six months. The median total direct cost of admission was INR 84,881.00 ($ 1232.34) CONCLUSION: The VHFR cohort had younger, more diabetic, and fewer hypertensive subjects than most cohorts. Admission for heart failure is a catastrophic health expenditure. Attempts should be made to ensure a reduction in readmission rates by targeting goal-directed therapy. As the most common cause of acute decompensation is pneumonia, vaccinating all patients before discharge may also help in this regard.

Coverage, quality, and correlates of childhood immunization in slums under national immunization program of India: A cross-sectional study

Adequate and quality immunization coverage plays a key role in controlling the outbreaks of vaccine preventable diseases. Places where immunization coverage is low, vaccine preventable diseases contribute to worse health outcomes. This is especially true in Indian slum dwellings where 33.0% of the urban population live. The aim of the study was to explore the coverage, quality, and correlates of primary immunization under national immunization program among children aged 12–23 months, living in slums of Mumbai. A community based cross-sectional survey was conducted. Parents or caretakers of 550 eligible children aged 12–23 months were interviewed using a structured interview schedule. Regression analysis was used to detect correlates of full immunization coverage (children who received one dose each of BCG, measles, and three doses each of DPT, OPV, and HBV by his/her first birthday) and of quality immunization coverage (children who received primary vaccines at appropriate age and intervals as mentioned above and had filled immunization card). Out of total 550 children, 402 (73.1%), 131 (23.8%), and 17 (3.1%) were fully, partially, and unimmunized, respectively. Almost 86.0% children received quality immunization coverage. In the regression analysis, reminder for immunization services was found to be the single most significant correlate of full and quality immunization coverage.

In this study, full immunization coverage was found to be below the expected level. This study also revealed that the awareness regarding the importance of adequate immunization was still lacking in the slum population. Emphasizing on reminders for immunization services, encouraging institutional deliveries, and scaling up use of postnatal care services may act as keys to improving the immunization coverage in Indian slums.