The Role of Shunt Occlusion During Extracorporeal Life Support.

INTRODUCTION: The current recommendation for systemic to pulmonary artery shunt (SPS) patients requiring extracorporeal life support (ECLS) is to keep the shunt open, maintaining a higher pump flow. The practice in our center is to totally occlude the shunt while on ECLS, and we are presenting the outcome of this strategy. METHODS: This is a retrospective analysis of patients who underwent SPS for cyanotic congenital heart disease with decreased pulmonary blood flow and required postoperative ECLS between January 2016 and December 2020. ECLS indication was excessive pulmonary blood flow, leading to either refractory low cardiac output syndrome (LCOS) or cardiac arrest. All patients had their shunts totally occluded soon after ECLS establishment. RESULTS: Of the 27 SPS patients who needed postoperative ECLS (13 refractory LCOS, 14 extracorporeal cardiopulmonary resuscitation), wherein the strategy of occluding the shunt on ECLS initiation was followed, 16 (59.3 %) survived ECLS weaning and eight (29.6%) survived to discharge. CONCLUSION: Increased flow to maintain systemic circulation for a SPS patient while on ECLS is an accepted strategy, but it should not be applied universally. A large subset of SPS patients, who require ECLS either due to cardiac arrest or refractory LCOS due to excessive pulmonary flow, might benefit from complete occlusion of the shunt soon after commencement of ECLS, especially in cases with frank pulmonary edema or haemorrhage in the pre-ECLS period. A prospective randomized trial could be ethically justified for the subset of patients receiving ECLS for the indication of excessive pulmonary blood flow.

The Role of Shunt Occlusion During Extracorporeal Life Support

ABSTRACT Introduction: The current recommendation for systemic to pulmonary artery shunt (SPS) patients requiring extracorporeal life support (ECLS) is to keep the shunt open, maintaining a higher pump flow. The practice in our center is to totally occlude the shunt while on ECLS, and we are presenting the outcome of this strategy. Methods: This is a retrospective analysis of patients who underwent SPS for cyanotic congenital heart disease with decreased pulmonary blood flow and required postoperative ECLS between January 2016 and December 2020. ECLS indication was excessive pulmonary blood flow, leading to either refractory low cardiac output syndrome (LCOS) or cardiac arrest. All patients had their shunts totally occluded soon after ECLS establishment. Results: Of the 27 SPS patients who needed postoperative ECLS (13 refractory LCOS, 14 extracorporeal cardiopulmonary resuscitation), wherein the strategy of occluding the shunt on ECLS initiation was followed, 16 (59.3 %) survived ECLS weaning and eight (29.6%) survived to discharge. Conclusion: Increased flow to maintain systemic circulation for a SPS patient while on ECLS is an accepted strategy, but it should not be applied universally. A large subset of SPS patients, who require ECLS either due to cardiac arrest or refractory LCOS due to excessive pulmonary flow, might benefit from complete occlusion of the shunt soon after commencement of ECLS, especially in cases with frank pulmonary edema or haemorrhage in the pre-ECLS period. A prospective randomized trial could be ethically justified for the subset of patients receiving ECLS for the indication of excessive pulmonary blood flow.

Spherical harmonics domain-based approach for source localization in presence of directional interference.

This paper presents a learning-based method for source localization in the presence of directional interference under reverberant and noisy conditions. The proposed method operates on the spherical harmonic decomposition of the spherical microphone array recordings to yield spherical harmonics coefficients as the features. An attention mechanism is incorporated through a binary mask that filters out the dominant undesired source components from the features before training. A convolutional neural network is trained to map the phase and magnitude of the filtered coefficients with the location class. Hence, the objective is to develop the binary mask followed by source localization.

Coronavirus disease 2019 convalescent children: outcomes after congenital heart surgery.

BACKGROUND: Children with exposure to coronavirus disease 2019 in recent times (asymptomatic or symptomatic infection) approaching congenital heart surgery programme are in increasing numbers. Understanding outcomes of such children will help risk-stratify and guide optimisation prior to congenital heart surgery. OBJECTIVE: The objective of the present study was to determine whether convalescent coronavirus disease 2019 children undergoing congenital heart surgery have any worse mortality or post-operative outcomes. DESIGN: Consecutive children undergoing congenital heart surgery from Oct 2020 to May 2021 were enrolled after testing for reverse transcription-polymerase chain reaction or rapid antigen test and immunoglobulin G antibody prior to surgery. Convalescent coronavirus disease 2019 was defined in any asymptomatic patient positive for immunoglobulin G antibodies and negative for reverse transcription-polymerase chain reaction or rapid antigen test anytime 6 weeks prior to surgery. Control patients were negative for any of the three tests. Mortality and post-operative outcomes were compared among the groups. RESULTS: One thousand one hundred and twenty-nine consecutive congenital heart surgeries were stratified as convalescence and control. Coronavirus disease 2019 Convalescent (n = 349) and coronavirus disease 2019 control (n = 780) groups were comparable for all demographic and clinical factors except younger and smaller kids in control. Convalescent children had no higher mortality, ventilation duration, ICU and hospital stay, no higher support with extracorporeal membrane oxygenation, high flow nasal cannula, no higher need for re-intubations, re-admissions, and no higher infections as central line-associated bloodstream infection, sternal site infection, and ventilator-associated pneumonia on comparison with coronavirus disease 2019 control children. CONCLUSIONS: Convalescent coronavirus disease 2019 does not have any unfavourable outcomes as compared to coronavirus disease 2019 control children. Positive immunoglobulin G antibody screening prior to surgery is suggestive of convalescence and supports comparable outcomes on par with control peers.

Predictors and outcome of early extubation in infants postcardiac surgery: A single-center observational study.

OBJECTIVE: The objective of the current study was to evaluate the timing of first extubation and compare the outcome of patient extubated early with others; we also evaluated the predictors of early extubation in our cohort. MATERIALS AND METHODS: This prospective cohort study included children <1 year of age undergoing surgery for congenital heart disease. Timing of first extubation was noted, and patients were dichotomized in the group taking 6 h after completion of surgery as cutoff for early extubation. The outcome of the patients extubated early was compared with those who required prolonged ventilation. Variables were compared between the groups, and predictors of early extubation were evaluated using multivariate logistic regression analysis. RESULTS: One hundred and ninety-four (33.8%) patients were extubated early including 2 extubation in operating room and 406 (70.7%) were extubated within 24 h. Four (0.7%) patients died without extubation. No significant difference in mortality and reintubation was observed between groups. Patient extubated early had a significant lower incidence of sepsis (P = 0.003) and duration of Intensive Care Unit (ICU) stay (P = 0.000). Age <6 months, risk adjustment for congenital heart surgery category ≥3, cardiopulmonary bypass time ≥80 min, aortic cross-clamp time ≥ 60 min, and vasoactive-inotropic score >10 were independently associated with prolonged ventilation. CONCLUSION: Early extubation in infants postcardiac surgery lowers pediatric ICU stay and sepsis without increasing the risk of mortality or reintubation. Age more than 6 months, less complex of procedure, shorter surgery time, and lower inotropic requirement are independent predictors of early extubation.

Vasoactive-ventilation-renal score in predicting outcome postcardiac surgery in children.

OBJECTIVE: The objective of this study was to evaluate vasoactive-ventilation-renal (VVR) score to predict outcome postcardiac surgery in children and establish the time at which the score is best to predict outcome. MATERIALS AND METHODS: This prospective cohort included children ≤18 years recovering from cardiac surgery for congenital heart disease. Data were collected from the Intensive Care Unit (ICU) and vasoactive-inotropic score (VIS) and VVR scores calculated at admission, 24 h, and 48 h postoperatively. Outcome of interest was prolonged length of ICU stay (defined as length of stay [LOS] in the upper 25th percentile) and ICU mortality. Correlation between the outcome and scores was obtained and receiver operating characteristic (ROC) curves generated. Independent association of the scores with the outcome was also established. RESULTS: One thousand ninety-seven patients were enrolled with a median age of 24 months (range: 2 days-18 years) including 14.6% with single ventricle physiology. Pediatric ICU LOS >89 h was considered prolonged, and mortality was 2.2%. VVR score correlated better with outcome and had greater area under the curve (AUC) for ROC curve than the corresponding VIS at each study time point. The AUC of ROC curve for VVR score was greatest at 48 h for predicting both prolonged LOS (0.87) and mortality (0.92). VVR score at 48 h remains strongly associated with both prolonged LOS (odds ratio [OR] - 1.24; P = 0.000) and mortality (OR - 1.16; P = 0.000). CONCLUSION: VVR score is effective and robust bedside method to predict prolonged LOS and mortality postpediatric cardiac surgery. VVR score at 48 h was the best to predict outcome.

Paediatric pulmonary haemorrhage: Independent lung ventilation as effective strategy in management.

Pulmonary haemorrhage is an uncommon symptom in paediatrics with the etiology varying among the series by age, location, and the diagnostic tests employed. Once airway protection and volume resuscitation are ensured, localization of the anatomic site of bleeding, isolation of the involved airway, control of haemorrhage and treatment of the underlying cause of becomes essential. In localized persistent bleeding, airway control may be achieved by lung isolation with double lumen endotracheal tube and synchronous independent lung ventilation.

Extubation in the operating room after cardiac surgery in children: a prospective observational study with multidisciplinary coordinated approach.

OBJECTIVE: This prospective observational study was undertaken to determine the feasibility of extubation of children in the operating room after cardiac surgery. DESIGN: A prospective observational study compared with historic controls. SETTING: A single tertiary care referral hospital. PARTICIPANTS: One thousand consecutive pediatric patients requiring cardiac surgery aged 1 day to 18 years. Patients with spinal deformity, neurologic problems, coagulopathy as diagnosed by high international normalized ratio (INR) more than 1.5, and patients preoperatively on mechanical ventilation were excluded from the study. Data were also reviewed for another 1,000 patients operated before the beginning of this study, which constituted historic controls. INTERVENTIONS: All 1,000 patients were considered as potential candidates for extubation in the operating room after cardiac surgery and managed by a combination of general anesthesia and neuraxial analgesia with a mixture of caudal morphine and dexmedetomidine, and extubation in the operating room was attempted after completion of the surgical procedure. These comprised the study group (SG). Data also were reviewed for another 1,000 patients before the beginning of this study when extubation in the operating room was not attempted and compared with this group to study the impact of extubation in the operating room on intensive care unit (ICU) stay and resource utilization. This data comprised the before-study group (BSG). MEASUREMENTS AND MAIN RESULTS: Eight hundred seventy-one (87.1%) patients were extubated in the operating room. This included 40% of neonates and 70%, 85%, and 91% of patients aged between 1 and 3 months, 3 months to 1 year, and more than 1 year, respectively. Forty-five patients (4.5%) required re-intubation within 24 hours, and 9 patients died among those extubated in the OR, but for reasons thought not to be related to extubation. The ICU stay was significantly less in the study group (2.56±1.84 v 5.4±2.32 days, p<0.0001) as compared to before-study group (BSG). The number of patients in the ICU (34.76±3.19 v 59.98±4.92, p<0.0001) and the number of patients on a ventilator (5.1±1.24 v 24.5±2.88, p<0.0001) on a daily basis were significantly less in the study group, reflecting positive impact on resource utilization. CONCLUSION: Extubation in the operating room was successful in 87.1% of the patients without any increase in mortality and morbidity, but with a decrease in ICU length of stay and less use of hospital resources.

Electro-oxidation and determination of antihistamine drug, cetirizine dihydrochloride at glassy carbon electrode modified with multi-walled carbon nanotubes.

A multi-walled carbon nanotube (MWCNT) film-modified glassy carbon electrode (GCE) was constructed for the determination of an antihistamine drug, cetirizine dihydrochloride (CTZH) using cyclic voltammetry (CV). Owing to the unique structure and extraordinary properties of MWCNT, the MWCNT film has shown an obvious electrocatalytic activity towards oxidation of CTZH, since it facilitates the electron transfer and significantly enhances the oxidation peak current of CTZH. All experimental parameters have been optimized. Under the optimum conditions, the oxidation peak current was linearly proportional to the concentration of CTZH in the range from 5.0×10(-7) to 1.0×10(-5)M. The detection limit was 7.07×10(-8)M with 180s accumulation. Finally, the proposed sensitive and simple electrochemical method was successfully applied to CTZH determination in pharmaceutical and urine samples.

Extracorporeal membrane oxygenation in postoperative pediatric cardiac surgical cases.

We prospectively analyzed the results of extracorporeal membrane oxygenation (ECMO) done in our Pediatric Cardiac Unit from January to December 2007. We present a series of nine patients who required ECMO after open heart surgery for congenital heart disease (CHD). The overall survival rate of these patients was 77.8%. The survival rate was 100% in patients who were electively put on ECMO after intracardiac repair for tetralogy of fallot, 50% in patients who were put on ECMO following the arterial switch operation and 50% in patients who were put on ECMO after VSD closure. Our results seem to suggest that patients placed on ECMO electively rather than after a cardiac arrest posts congenital cardiac surgeries have a better outcome.

Influence of surface chemistry of mesoporous alumina with wide pore distribution on controlled drug release.

The crucial role of the drug carrier surface chemical moeities on the uptake and in vitro release of drug is discussed here in a systematic manner. Mesoporous alumina with a wide pore size distribution (2-7 nm) functionalized with various hydrophilic and hydrophobic surface chemical groups was employed as the carrier for delivery of the model drug ibuprofen. Surface functionalization with hydrophobic groups resulted in low degree of drug loading (approximately 20%) and fast rate of release (85% over a period of 5 h) whereas hydrophilic groups resulted in a significantly higher drug payloads (21%-45%) and slower rate of release (12%-40% over a period of 5 h). Depending on the chemical moiety, the diffusion controlled ( proportional, varianttime(-)(0.5)) drug release was additionally observed to be dependent on the mode of arrangement of the functional groups on the alumina surface as well as on the pore characteristics of the matrix. For all mesoporous alumina systems the drug dosages were far lower than the maximum recommended therapeutic dosages (MRTD) for oral delivery. We envisage that the present study would aid in the design of delivery systems capable of sustained release of multiple drugs.

Electro-oxidation and determination of trazodone at multi-walled carbon nanotube-modified glassy carbon electrode.

A simple and rapid electrochemical method was developed for the determination of trace-level trazodone, based on the excellent properties of multi-walled carbon nanotubes (MWCNTs). The MWCNT-modified glassy carbon electrode was constructed and the electrochemical behavior of trazodone was investigated in detail. The cyclic voltammetric results indicate that MWCNT-modified glassy carbon electrode can remarkably enhance electrocatalytic activity towards the oxidation of trazodone in neutral solutions. It leads to a considerable improvement of the anodic peak current for trazodone, and allows the development of a highly sensitive voltammetric sensor for the determination of trazodone. Trazodone could effectively accumulate at this electrode and produce two anodic peaks at about 0.73 V and 1.00 V. The electrocatalytic behavior was further exploited as a sensitive detection scheme for the trazodone determination by differential-pulse voltammetry. Under optimized conditions, the concentration range and detection limit are 0.2-10 microM and 24 nM, respectively for trazodone. The proposed method was successfully applied to trazodone determination in pharmaceutical samples. The analytical performance of this sensor has been evaluated for detection of analyte in urine as a real sample.

Voltammetric oxidation and determination of cinnarizine at glassy carbon electrode modified with multi-walled carbon nanotubes.

The voltammetric oxidation of cinnarizine was investigated. In pH 2.5 Britton-Robinson buffer, cinnarizine shows an irreversible oxidation peak at about 1.20 V at a multi-walled carbon nanotube (MWCNT)-modified glassy carbon electrode. The cyclic voltammetric results indicate that MWCNT-modified glassy carbon electrode can remarkably enhance electrocatalytic activity towards the oxidation of cinnarizine. The electrocatalytic behavior was further exploited as a sensitive detection scheme for the cinnarizine determination by differential-pulse voltammetry. Under optimized conditions, the concentration range and detection limit are 9.0x10(-8) to 6.0x10(-6) M and 2.58x10(-9) M, respectively for cinnarizine. The proposed method was successfully applied to cinnarizine determination in pharmaceutical samples. The analytical performance of this sensor has been evaluated for the detection of analyte in urine as a real sample.

Flash pulmonary edema in a post arterial switch operation - High flow oxygen as a treatment modality.

We report a case of a 3-year-old boy who underwent an arterial switch operation with relief of left ventricular outflow tract obstruction and later presented with recurrent episodes of flash pulmonary edema. High-flow humidified oxygen with positive pressure support (Vapotherm) was used as a treatment modality, thereby avoiding intubation and mechanical ventilation.