Recurrence of ventricular fibrillation in out-of-hospital cardiac arrest: Clinical evidence and underlying ionic mechanisms.

Defibrillation remains the optimal therapy for terminating ventricular fibrillation (VF) in out-of-hospital cardiac arrest (OHCA) patients, with reported shock success rates of ∼90%. A key persistent challenge, however, is the high rate of VF recurrence (∼50-80%) seen during post-shock cardiopulmonary resuscitation (CPR). Studies have shown that the incidence and time spent in recurrent VF are negatively associated with neurologically-intact survival. Recurrent VF also results in the administration of extra shocks at escalating energy levels, which can cause cardiac dysfunction. Unfortunately, the mechanisms underlying recurrent VF remain poorly understood. In particular, the role of chest-compressions (CC) administered during CPR in mediating recurrent VF remains controversial. In this review, we first summarize the available clinical evidence for refibrillation occurring during CPR in OHCA patients, including the postulated contribution of CC and non-CC related pathways. Next, we examine experimental studies highlighting how CC can re-induce VF via direct mechano-electric feedback. We postulate the ionic mechanisms involved by comparison with similar phenomena seen in commotio cordis. Subsequently, the hypothesized contribution of partial cardiac reperfusion (either as a result of CC or CC independent organized rhythm) in re-initiating VF in a globally ischaemic heart is examined. An overview of the proposed ionic mechanisms contributing to VF recurrence in OHCA during CPR from a cellular level to the whole heart is outlined. Possible therapeutic implications of the proposed mechanistic theories for VF recurrence in OHCA are briefly discussed.

The impact of alternate defibrillation strategies on shock-refractory and recurrent ventricular fibrillation: A secondary analysis of the DOSE VF cluster randomized controlled trial.

BACKGROUND: The DOSE VF randomized controlled trial (RCT) employed a pragmatic definition of refractory ventricular fibrillation (VF after three successive shocks). However, it remains unclear whether the underlying rhythm during the first three shocks was shock-refractory or recurrent VF. OBJECTIVE: To explore the relationship between alternate defibrillation strategies employed during the DOSE VF RCT and the type of VF, either shock-refractory VF or recurrent VF, on patient outcomes. METHODS: We performed a secondary analysis of the DOSE VF RCT. We categorized cases as shock-refractory or recurrent VF based on pre-randomization shocks (shocks 1-3). We then analyzed all subsequent (post-randomization) shocks to assess the impact of standard, vector change (VC) or double sequential external defibrillation (DSED) shocks on clinical outcomes employing logistic regression adjusted for Utstein variables, antiarrhythmics, and epinephrine. RESULTS: We included 345 patients; 60 (17%) shock-refractory VF, and 285 (83%) recurrent VF. Patients in recurrent VF had greater survival than shock-refractory VF (OR: 2.76 95% CI [1.04, 7.27]). DSED was superior to standard defibrillation for survival overall, and for patients with shock-refractory VF (28.6% vs 0%, p = 0.041) but not for those in recurrent VF. DSED was superior to standard defibrillation for return of spontaneous circulation (ROSC) and neurologic survival for shock-refractory and recurrent VF. VC defibrillation was not superior for survival or ROSC overall, for shock-refractory, or recurrent VF groups, but was superior for VF termination across all groups. CONCLUSION: DSED appears to be the superior defibrillation strategy in the DOSE VF trial, irrespective of whether the preceding VF is shock-refractory or recurrent.

Labral Support Shelf Acetabuloplasty for Late Presenting Perthes Disease: Outcomes in Indian Patients.

Introduction: The treatment of late-presenting Perthes disease with extrusion is controversial and debatable. One of the options available is the labral shelf acetabuloplasty (LSA). Aim: The aim of the study was to evaluate the results of LSA in late-presenting Perthes disease in terms of clinic-radiological outcome measures. Materials and Methods: A retrospective analysis of prospectively collected data of patients with late presenting Perthes disease (Elizabethtown stage 2B onwards) treated by LSA by 2 experienced paediatric orthopaedic surgeons was performed. Data was collected of clinical parameters such as hip range of motion(ROM) and Harris Hip score and radiological parameters such as acetabular height, width and volume, shelf width, Centre Edge angle(CEA) and the lateral extrusion. Results: Thirty-five patients (28 males and 7 females) treated between 2012 to 2019 were analyzed. Majority were in Elizabethtown stage 3A (23) followed by 2B and 3B (12 each). At a mean follow up of 36 months, the hip ROM and the Harris Hip Score (from 65 ± 3.5 to 81.33 ± 7.12) improved significantly and there was a statistically significant improvement in terms of all radiological parameters. Majority of the hips were in Stulberg grade 3 (20) followed by grade 1 and 2 (7 each) and Stulberg 4 (1). There were no major complications in any of the patients of the series. Conclusion: Labral support shelf acetabuloplasty is a valuable surgery for late presenting Perthes disease and helps in maintenance of good coverage and allows restoration of range of motion over time.

Identifying appropriate prediction models for estimating hourly temperature over diverse agro-ecological regions of India.

The present study tests the accuracy of four models in estimating the hourly air temperatures in different agroecological regions of the country during two major crop seasons, kharif and rabi, by taking daily maximum and minimum temperatures as input. These methods that are being used in different crop growth simulation models were selected from the literature. To adjust the biases of estimated hourly temperature, three bias correction methods (Linear regression, Linear scaling and Quantile mapping) were used. When compared with the observed data, the estimated hourly temperature, after bias correction, is reasonably close to the observed during both kharif and rabi seasons. The bias-corrected Soygro model exhibited its good performance at 14 locations, followed by the WAVE model and Temperature models at 8 and 6 locations, respectively during the kharif season. In the case of rabi season, the bias-corrected Temperature model appears to be accurate at more locations (21), followed by WAVE and Soygro models at 4 and 2 locations, respectively. The pooled data analysis showed the least error between estimated (uncorrected and bias-corrected) and observed hourly temperature from 04 to 08 h during kharif season while it was 03 to 08 h during the rabi season. The results of the present study indicated that Soygro and Temperature models estimated hourly temperature with better accuracy at a majority of the locations situated in the agroecological regions representing different climates and soil types. Though the WAVE model worked well at some of the locations, estimation by the PL model was not up to the mark in both kharif and rabi seasons. Hence, Soygro and Temperature models can be used to estimate hourly temperature data during both kharif and rabi seasons, after the bias correction by the Linear Regression method. We believe that the application of the study would facilitate the usage of hourly temperature data instead of daily data which in turn improves the precision in predicting phenological events and bud dormancy breaks, chilling hour requirement etc.

Inappropriate Shock Delivery Is Common During Pediatric In-Hospital Cardiac Arrest.

OBJECTIVES: To characterize inappropriate shock delivery during pediatric in-hospital cardiac arrest (IHCA). DESIGN: Retrospective cohort study. SETTING: An international pediatric cardiac arrest quality improvement collaborative Pediatric Resuscitation Quality [pediRES-Q]. PATIENTS: All IHCA events from 2015 to 2020 from the pediRES-Q Collaborative for which shock and electrocardiogram waveform data were available. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We analyzed 418 shocks delivered during 159 cardiac arrest events, with 381 shocks during 158 events at 28 sites remaining after excluding undecipherable rhythms. We classified shocks as: 1) appropriate (ventricular fibrillation [VF] or wide complex ≥ 150/min); 2) indeterminate (narrow complex ≥ 150/min or wide complex 100-149/min); or 3) inappropriate (asystole, sinus, narrow complex < 150/min, or wide complex < 100/min) based on the rhythm immediately preceding shock delivery. Of delivered shocks, 57% were delivered appropriately for VF or wide complex rhythms with a rate greater than or equal to 150/min. Thirteen percent were classified as indeterminate. Thirty percent were delivered inappropriately for asystole (6.8%), sinus (3.1%), narrow complex less than 150/min (11%), or wide complex less than 100/min (8.9%) rhythms. Eighty-eight percent of all shocks were delivered in ICUs or emergency departments, and 30% of those were delivered inappropriately. CONCLUSIONS: The rate of inappropriate shock delivery for pediatric IHCA in this international cohort is at least 30%, with 23% delivered to an organized electrical rhythm, identifying opportunity for improvement in rhythm identification training.

Radiotherapy molds: An approach to fabricating facial moulage.

Impression procedures for recording large maxillofacial defects are tedious and difficult because of the unavailability of stock impression trays. This article describes the procedure of fabricating a straightforward facial moulage with predictable accuracy by using a reusable radiotherapy thermoplastic sheet.

Osteoradionecrosis of the jaws: A retrospective cohort study.

Introduction: Radiotherapy (RT) combined with chemotherapy and surgery is the indicated treatment for head and neck cancers. Even with the advent of modern technological advances in RT and improved oral hygiene awareness, osteoradionecrosis (ORN) still remains as one of the most debilitating side effects of RT. Methodology: This is a retrospective review assessing 72 patients aged over 18 years of age reporting in the Dental Department, for treatment of ORN from April 2010 to July 2019. Each patient was clinically examined and treated according to standard protocol. The stage of ORN was noted at the diagnosis and at follow-up. The demographic data, the tumor characteristics, and the treatment of patients were evaluated using descriptive statistics. Results: At the time of diagnosis, 84.7% of the study population was found to have Epstein Type II chronic persistent nonprogressive lesions and 11.1% of the cohort had Type III active progressive lesions. Statistically significant correlation (P = 0.00) was found for ORN grade at diagnosis and at follow-up. ORN being a chronic pathology, stabilization of the disease was observed in 72.3% of cases. The resolution of the necrotic lesion and down staging of the disease was seen only in 2.8% of patients. Conclusion: ORN is mainly a chronic long standing pathology which is difficult to treat completely. Stabilization of symptoms and preventing further spread of the necrotic lesion should be the ultimate aim of the treatment to improve the quality of life of the patients.

Longitudinal change in ATN biomarkers in cognitively normal individuals.

BACKGROUND: Biomarkers for amyloid, tau, and neurodegeneration (ATN) have predictive value for clinical progression, but it is not clear how individuals move through these stages. We examined changes in ATN profiles over time, and investigated determinants of change in A status, in a sample of cognitively normal individuals presenting with subjective cognitive decline (SCD). METHODS: We included 92 individuals with SCD from the SCIENCe project with [18F]florbetapir PET (A) available at two time points (65 ± 8y, 42% female, MMSE 29 ± 1, follow-up 2.5 ± 0.7y). We additionally used [18F]flortaucipir PET for T and medial temporal atrophy score on MRI for N. Thirty-nine individuals had complete biomarker data at baseline and follow-up, enabling the construction of ATN profiles at two time points. All underwent extensive neuropsychological assessments (follow-up time 4.9 ± 2.8y, median number of visits n = 4). We investigated changes in biomarker status and ATN profiles over time. We assessed which factors predisposed for a change from A- to A+ using logistic regression. We additionally used linear mixed models to assess change from A- to A+, compared to the group that remained A- at follow-up, as predictor for cognitive decline. RESULTS: At baseline, 62% had normal AD biomarkers (A-T-N- n = 24), 5% had non-AD pathologic change (A-T-N+ n = 2,) and 33% fell within the Alzheimer's continuum (A+T-N- n = 9, A+T+N- n = 3, A+T+N+ n = 1). Seventeen subjects (44%) changed to another ATN profile over time. Only 6/17 followed the Alzheimer's disease sequence of A → T → N, while 11/17 followed a different order (e.g., reverted back to negative biomarker status). APOE ε4 carriership inferred an increased risk of changing from A- to A+ (OR 5.2 (95% CI 1.2-22.8)). Individuals who changed from A- to A+, showed subtly steeper decline on Stroop I (ß - 0.03 (SE 0.01)) and Stroop III (- 0.03 (0.01)), compared to individuals who remained A-. CONCLUSION: We observed considerable variability in the order of ATN biomarkers becoming abnormal. Individuals who became A+ at follow-up showed subtle decline on tests for attention and executive functioning, confirming clinical relevance of amyloid positivity.

Evaluating area-specific adaptation strategies for rainfed maize under future climates of India.

This study investigates the spatio-temporal changes in maize yield under projected climate and identified the potential adaptation measures to reduce the negative impact. Future climate data derived from 30 general circulation models were used to assess the impact of future climate on yield in 16 major maize growing districts of India. DSSAT model was used to simulate maize yield and evaluate adaptation strategies during mid (2040-69) and end-centuries (2070-99) under RCP 4.5 and 8.5. Genetic coefficients were calibrated and validated for each of the study locations. The projected climate indicated a substantial increase in mean seasonal maximum (0.9-6.0 °C) and minimum temperatures (1.1-6.1 °C) in the future (the range denotes the lowest and highest change during all the four future scenarios). Without adaptation strategies, climate change could reduce maize yield in the range of 16% (Tumkur) to 46% (Jalandhar) under RCP 4.5 and 21% (Tumkur) to 80% (Jalandhar) under RCP 8.5. Only at Dharwad, the yield could remain slightly higher or the same compared to the baseline period (1980-2009). Six adaptation strategies were evaluated (delayed sowing, increase in fertilizer dose, supplemental irrigation, and their combinations) in which a combination of those was found to be effective in majority of the districts. District-specific adaptation strategies were identified for each of the future scenarios. The findings of this study will enable in planning adaptation strategies to minimize the negative impact of projected climate in major maize growing districts of India.

Two-piece oral facial prothesis retained with magnets for a complex maxillary facial defect: A clinical report.

Total flap failure is a devastating complication in head and neck reconstruction. This clinical report describes the rehabilitation of an extensive maxillectomy defect communicating with the midface by using a 2-piece magnet-retained orofacial prosthesis fabricated in heat-processed acrylic resin. The innovative design and choice of material allowed early rehabilitation of a patient receiving palliative care at a resource-constrained tertiary care oncology center. Prosthetic treatment served to reduce the period of hospitalization and helped the patient to resocialize.

Panoramic Endocardial Optical Mapping Demonstrates Serial Rotors Acceleration and Increasing Complexity of Activity During Onset of Cholinergic Atrial Fibrillation.

Background Activation during onset of atrial fibrillation is poorly understood. We aimed at developing a panoramic optical mapping system for the atria and test the hypothesis that sequential rotors underlie acceleration of atrial fibrillation during onset. Methods and Results Five sheep hearts were Langendorff perfused in the presence of 0.25 µmol/L carbachol. Novel optical system recorded activations simultaneously from the entire left and right atrial endocardial surfaces. Twenty sustained (>40 s) atrial fibrillation episodes were induced by a train and premature stimuli protocol. Movies obtained immediately (Initiation stage) and 30 s (Early Stabilization stage) after premature stimulus were analyzed. Serial rotor formation was observed in all sustained inductions and none in nonsustained inductions. In sustained episodes maximal dominant frequency increased from (mean±SD) 11.5±1.74 Hz during Initiation to 14.79±1.30 Hz at Early Stabilization (P<0.0001) and stabilized thereafter. At rotor sites, mean cycle length (CL) during 10 prerotor activations increased every cycle by 0.53% (P=0.0303) during Initiation and 0.34% (P=0.0003) during Early Stabilization. In contrast, CLs at rotor sites showed abrupt decreases after the rotors appearances by a mean of 9.65% (P<0.0001) during both stages. At Initiation, atria-wide accelerations and decelerations during rotors showed a net acceleration result whereby post-rotors atria-wide minimal CL (CLmin) were 95.5±6.8% of the prerotor CLmin (P=0.0042). In contrast, during Early Stabilization, there was no net acceleration in CLmin during accelerating rotors (prerotor=84.9±11.0% versus postrotor=85.8±10.8% of Initiation, P=0.4029). Levels of rotor drift distance and velocity correlated with atria-wide acceleration. Nonrotor phase singularity points did not accelerate atria-wide activation but multiplied during Initiation until Early Stabilization. Increasing number of singularity points, indicating increased complexity, correlated with atria-wide CLmin reduction (P<0.0001). Conclusions Novel panoramic optical mapping of the atria demonstrates shortening CL at rotor sites during cholinergic atrial fibrillation onset. Atrial fibrillation acceleration toward Early Stabilization correlates with the net result of atria-wide accelerations during drifting rotors activity.

Oral and dental health status in patients undergoing neoadjuvant chemotherapy for locally advanced head and neck cancer.

OBJECTIVE: A prospective, longitudinal assessment of oral and dental health status was done from baseline until treatment completion in patients scheduled to receive neoadjuvant chemotherapy (NACT) for locally advanced head and neck cancer (LAHNC). STUDY DESIGN: One hundred fifty consecutive, treatment-naïve adult patients with biopsy-proven LAHNC scheduled to receive NACT were recruited. One hundred thirty-five patients completed all assessments at 3 designated time points: baseline (T0), midtreatment (T1), and posttreatment (T2). Variables assessed were: Oral Hygiene Index-Simplified (OHI-S) score; decayed, missing, or filled teeth (DMFT) score; mucositis grade; pain score; and grade of trismus. RESULTS: Median OHI-S scores showed a statistically significant increase (higher the score, poorer the oral hygiene) when the patients were evaluated from baseline to completion of NACT (T1 vs. T2; T0 vs. T2; P < .001), which indicated a decrease in oral health. There was no change in median DMFT score (P = .32), but a significant change was seen in all-grade mucositis over time (P < .001). Median pain scores and trismus grades decreased significantly (P < .001) over time. CONCLUSIONS: There was a decrease in oral health status without any change in dental health seen in patients undergoing NACT. Mucositis was initially noted as an aftermath of chemotherapy, which resolved with time.

Lower-Limb Ischemia at Birth Because of Spontaneous Arterial Thrombosis: A Case Report.

CASE: A full-term neonate presented with right lower extremity ischemia at birth because of spontaneous thrombosis of the right common iliac artery. He was initially managed with supportive treatment, anticoagulation, and dressings; however, advanced gangrenous changes precluded salvage of the ischemic limb. A guillotine amputation was performed at day 15 of life, and the stump went on to heal well by secondary intention. CONCLUSION: Thromboembolic events occurring in infancy are well-recognized phenomena; however, it is far rarer to encounter a neonate born with "congenital gangrene". We discuss the etiology, approach to diagnosis, and treatment of this rare but devastating condition.

A Comparative Study of Topical 5% 5-Fluorouracil with Needling versus 30% Trichloroacetic Acid with Needling in the Treatment of Plantar Warts.

BACKGROUND: Warts are benign proliferations of keratinocytes caused by Human Papilloma Virus (HPV). Plantar warts are caused by HPV types 1, 2, 4, 27 and 57. It is challenging to treat them due to frequent recurrences. AIM: To compare the efficacy and safety of topical 5% 5-Fluorouracil (5-FU) with needling versus 30% Trichloroacetic acid (TCA) with needling in the treatment of plantar warts. MATERIALS AND METHODS: Sixty consecutive patients of plantar warts were randomly allocated into two groups of 30 each and treated with either 30% TCA with needling or 5% 5-FU with needling once in four weeks, until complete clearance of warts or for a maximum of three sessions. Baseline clinical photographs were taken and subjective response at the end of treatment was recorded. Objective assessment at 4, 8, and 12 weeks was carried out and outcome was evaluated by reduction in number and size of warts. Adverse effects of each group were noted and compared. Follow-up of patients was done at 6 months for clinical assessment of results and to study recurrence. RESULTS: Out of 30 patients in 30% TCA group, 28 patients (93.33%) had complete response and 02 patients (6.66%) had partial response at the end of 12 weeks. In 5-FU group, 26 patients (86.66%) showed complete response, 02 patients (6.66%) had partial response, and 02 patients (6.66%) had no response to treatment. The mean reduction in size and number of warts was better in the TCA group and was significant at 4th week of follow up while at the end of 8th week and 12th week, the response was identical. There was no recurrence of warts in the complete responders at the end of 6 months. The main adverse effect seen in both groups was pain at the needling site. CONCLUSION: Needling with both topical 5% 5-FU and 30% TCA are highly effective in clearing plantar warts. However, 30% TCA has the advantage of early action and complete clearance of plantar warts with fewer adverse effects.

Statistical Analysis of Polymer Nanocomposites for Mechanical Properties.

Epoxy resins, due to their high stiffness, ease of processing, good heat, and chemical resistance obtained from cross-linked structures, have found applications in electronics, adhesives coatings, industrial tooling, and aeronautic and automotive industries. These resins are inherently brittle, which has limited their further application. The emphasis of this study is to improve the properties of the epoxy resin with a low-concentration (up to 0.4% by weight) addition of Multi-Walled Carbon Nanotubes (MWCNTs). Mechanical characterization of the modified composites was conducted to study the effect of MWCNTs infusion in the epoxy resin. Nanocomposites samples showed significantly higher tensile strength and fracture toughness compared to pure epoxy samples. The morphological studies of the modified composites were studied using Scanning Electron Microscopy (SEM).

Effect of Amplitude Spectral Area on Termination of Fibrillation and Outcomes in Pediatric Cardiac Arrest.

Background Amplitude spectral area (AMSA) predicts termination of fibrillation (TOF) with return of spontaneous circulation (ROSC) and survival in adults but has not been studied in pediatric cardiac arrest. We characterized AMSA during pediatric cardiac arrest from a Pediatric Resuscitation Quality Collaborative and hypothesized that AMSA would be associated with TOF and ROSC. Methods and Results Children aged <18 years with cardiac arrest and ventricular fibrillation were studied. AMSA was calculated for 2 seconds before shock and averaged for each subject (AMSA-avg). TOF was defined as termination of ventricular fibrillation 10 seconds after defibrillation to any non-ventricular fibrillation rhythm. ROSC was defined as >20 minutes without chest compressions. Univariate and multivariable logistic regression analyses controlling for weight, current, and illness category were performed. Primary end points were TOF and ROSC. Secondary end points were 24-hour survival and survival to discharge. Between 2015 and 2019, 50 children from 14 hospitals with 111 shocks were identified. In univariate analyses AMSA was not associated with TOF and AMS-Aavg was not associated with ROSC. Multivariable logistic regression showed no association between AMSA and TOF but controlling for defibrillation average current and illness category, there was a trend to significant association between AMSA-avg and ROSC (odds ratio, 1.10 [1.00‒1.22] P=0.058). There was no significant association between AMSA-avg and 24-hour survival or survival to hospital discharge. Conclusions In pediatric patients, AMSA was not associated with TOF, whereas AMSA-avg had a trend to significance for association in ROSC, but not 24-hour survival or survival to hospital discharge. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02708134.

Preparation of cement spacer in treatment of segmental bone defects in children by the induced membrane technique: A technical note.

The Masquelet Induced Membrane Technique (IMT) is one of the tools in the surgeon's armamentarium for the management of segmental bone defects. The first stage of the IMT includes the insertion of a cement spacer, which is typically fashioned by the free-hand technique. We propose a novel technique for preparation of the cement spacer using a split syringe barrel as a mould. This technique produces a uniformly cylindrical spacer with minimum cement spillage, while also minimizing thermal damage to the surrounding soft tissues. It is a simple and cost-effective method that can be adapted for use in any long bone in children.

Preventive aspect of ayurveda and yoga towards newly emerging disease COVID-19.

The ongoing coronavirus pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS CoV 2) and unique in various facets. The earlier experience from the past severe acute respiratory syndrome (SARS) epidemics seem to be insufficient and there is need for better strategies in public health and medical care. Ayurved & Yog are well known for their preventive and therapeutic aspect, but not getting utilized properly for prevention of Covid 19 crisis which may also be helpful as supportive therapy along with current line of management. This paper is aimed at unrevealing the role of Ayurved and Yoga guidelines established by Department of AYUSH for prevention from SARS-CoV-2 by providing help to improving the quality of supportive/prophylactic therapy in relation with their immunity.