Comparative Effect of High-Frequency Nasal Cannula and Noninvasive Ventilation on the Work of Breathing and Postoperative Pulmonary Complication after Pediatric Congenital Cardiac Surgery: A Prospective Randomized Controlled Trial.

BACKGROUND: Various forms of commonly used noninvasive respiratory support strategies have considerable effect on diaphragmatic contractile function which can be evaluated using sonographic diaphragm activity parameters. OBJECTIVE: To compare the magnitude of respiratory workload decreased as assessed by thickening fraction of the diaphragm and longitudinal diaphragmatic strain while using high-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) modes [nasal intermittent positive pressure ventilation (NIPPV) and bilevel positive airway pressure (BiPAP)] in pediatric patients after cardiothoracic surgery. METHODOLOGY: This prospective randomized controlled trial was performed at a tertiary care surgical intensive care unit in postcardiac surgery patients aged between 1 and 48 months, who were randomly allocated into three groups: 1) HFNC (with flows at 2 L/kg/min), 2) NIPPV via RAMS cannula in PSV mode (pressure support 8 cmH2O, PEEP 5 cmH2O), and 3) BiPAP in nCPAP mode (CPAP of 5 cmH2O). Measurements were recorded at baseline after extubation (R0) and subsequently every 12 hourly (R1, R2, R3, R4, R5) at 12, 24, 36, 48, and 60 hours respectively until therapy was discontinued. RESULTS: Sixty patients were included, with 20 patients each in the NIPPV group, HFNC group, and BiPAP group. Longitudinal strain at crura of diaphragm was lower in the BiPAP group as compared to HFNC group at R2-R4 [R2 (-4.27± -2.73 vs - 8.40± -6.40, P = 0.031), R3 (-5.32± -2.28 vs -8.44± -5.6, P = 0.015), and R4 (-3.8± -3.42 vs -12.4± -7.12, P = 0.040)]. PFR was higher in HFNC than NIPPV group at baseline and R1-R3[R0 (323 ± 114 vs 264 ± 80, P = 0.008), R1 (311 ± 114 vs 233 ± 66, P = 0.022), R2 (328 ± 116 vs 237 ± 4, P = 0.002), R3 (346 ± 112 vs 238 ± 54, P = 0.001)]. DTF and clinical parameters of increased work of breathing remain comparable between three groups. The rate of reintubation (within 48 hours of extubation or at ICU discharge) was 0.06% (1 in NIPPV, 1 in BiPAP, 2 in HFNC) and remain comparable between groups (P = 1.0). CONCLUSION: BiPAP may provide better decrease in work of breathing compared to HFNC as reflected by lower crural diaphragmatic strain pattern. HFNC may provide better oxygenation compared to NIPPV group, as reflected by higher PFR ratio. Failure rate and safety profile are similar among different methods used.

Author Response.

How to cite this article: Niyogi SG, Naskar C, Singh A, Kumar B, Grover S. Author Response. Indian J Crit Care Med 2024;28(2):188.

Melatonin and Melatonin Agonists for Prevention of Delirium in the Cardiac Surgical ICU: A Meta-analysis.

Aim and Background: Delirium is highly prevalent in the immediate postoperative period following cardiac surgery and adversely impacts outcomes. Melatonin has been increasingly used in pharmacological prevention of delirium. We aimed to synthesize the available evidence concerning the role of melatonin and melatonin agonists in preventing delirium in patients after cardiac surgery. Materials and methods: PubMed, Google Scholar, and Web of Science databases were searched for relevant randomized and non-randomized trials in adults undergoing cardiac surgery investigating melatonin agonists to prevent delirium. Studies incorporating transplants, preoperative organ support, prophylactic antipsychotics, or children were excluded. Risk-of-bias was assessed using Cochrane ROB 2.0 and ROBINS-I tools. A systematic review and meta-analysis were conducted, calculating pooled odds ratio (OR) for the incidence of postoperative delirium using a random effects model with the Mantel-Haenszel method with restricted maximum-likelihood estimator. Trial sequential analysis was also carried out for the primary outcome. Results: Six randomized trials and one non-randomized trial involving 1,179 patients were included. Incidence of delirium was 16.7 and 29.6% in the intervention and comparator groups respectively, indicating a pooled OR of 0.44 [95% confidence interval (CI) 0.27 - 0.71, p = 0.04] favoring melatonin. Two studies had a high risk of bias, and I2 statistics indicated significant heterogeneity. However, publication bias was insignificant, and trial sequential analysis indicated the significance of the attained effect size. Conclusion: Based on available studies, perioperative melatonin use significantly decreases postoperative incidence of delirium after adult cardiac surgery. However, the available quality of evidence is low, and larger trials with standardization of nonpharmacological delirium prevention interventions, in high-risk cohorts, and exploring various dosages and regimens should be carried out. How to cite this article: Niyogi SG, Naskar C, Singh A, Kumar B, Grover S. Melatonin and Melatonin Agonists for Prevention of Delirium in the Cardiac Surgical ICU: A Meta-analysis. Indian J Crit Care Med 2023;27(11):837-844.

Effect of perioperative use of oral triidothyronine for infants undergoing complex congenital cardiac surgeries under cardiopulmonary bypass: A double-blinded randomised controlled study.

Background: Thyroid hormone metabolism disrupts after cardiopulmonary bypass both in adults and pediatric patients. This is known as Euthyroid sick syndrome, and it is more evident in pediatric patients who were undergoing complex cardiac surgeries compared to adults. This decrease in serum T3 levels increases the incidence of low cardiac output, requirement of inotropes, prolonged mechanical ventilation, and prolonged intensive care unit (ICU) stay. Aims and Objectives: The primary objective was to compare the mean Vasoactive-inotropic score (VIS) at 72 hours postoperatively between T3 and Placebo groups. Materials and Methods: One hundred patients were screened, and 88 patients were included in the study. Triidothyronine 1 mic/kg 10 doses 8th hourly was given orally postoperatively to cases and sugar sachets to controls. The blood samples for analysis of FT3, FT4, and TSH were taken every 24 hours postoperatively, and baseline values were taken after induction. Mean VIS scores, ejection Fraction (EF), Left ventricular outflow tract velocity time integral (LVOT VTi), hemodynamics and partial pressure of oxygen/ fraction of inspired oxygen(PaO2/FiO2) were recorded daily. Results: The Mean VIS scores at 72 Hours postoperatively were significantly less in the T3 group (5.49 ± 6.2) compared to the Placebo group (13.6 ± 11.7). The PaO2/FiO2 ratios were comparatively more in the T3 group than the Placebo group. The serum levels of FT3 FT4 were significantly higher in the T3-supplemented group than the Placebo group. The VIS scores were significantly lower from 48 hours postoperatively in children < 6 months of age. Conclusion: In this study, we observed that supplementing T3 postoperatively decreases the ionotropic requirement from 72 hours postoperatively. This is more useful in children <6 months of age undergoing complex cardiac surgeries.

Utility of Transfontanelle Ultrasound in Predicting the Fluid Responsiveness in Children After Repair of Congenital Heart Diseases: A Prospective Observational Study.

OBJECTIVES: Postoperative fluid management in children undergoing cardiac surgery requires a balanced optimization. The blood flow velocity variation in the internal carotid artery (ΔICA) measured through transfontanelle ultrasound has been shown to predict fluid responsiveness during cardiac surgery. It may provide an excellent window to study fluid responsiveness in infants during the postoperative period when the intensivist is faced with the challenges of poor echocardiographic window. The authors aimed to observe the correlation between ΔICA measured on transfontanelle ultrasound with the respiratory variability of peak aortic blood flow velocity (ΔVpeak) on transthoracic echocardiography as a marker of fluid responsiveness in infants on mechanical ventilation during the postoperative period after cardiac surgery. DESIGN: A prospective observational study. SETTING: The postcardiac surgery intensive care unit (ICU) of a tertiary care hospital. PARTICIPANTS: Thirty infants undergoing congenital cardiac surgery. INTERVENTIONS: A fluid bolus of 10 mL/kg administered over 10 minutes at 1 and 6 hours after ICU admission. Patients were categorized into fluid responders and nonresponders based on >15% increase in the indexed stroke volume. MEASUREMENTS AND MAIN RESULTS: A total of 50 fluid boluses were administered in 30 patients. Among these, 22 (73.33%) were responders and 8 (26.67%) were nonresponders. There was moderate correlation between ΔICA and peak aortic blood flow velocity variation (ΔVpeak) (r = 0.59, p ≤ 0.001). The ΔVpeak >14.74% had 68% sensitivity and 75% specificity to predict fluid responsiveness (area under the receiver operating characteristic [AUROC], 0.749; p = 0.001; positive likelihood ratio, 2.71; negative likelihood ratio, 0.43). The ΔICA >9.85% could predict fluid responsiveness in infants (AUROC, 0.728; p = 0.003; 75% sensitivity; 60% specificity; positive likelihood ratio, 1.85; negative likelihood ratio, 0.42). Among children younger than 6 months, ΔICA >9.85% was a better predictor of fluid responsiveness (AUROC, 0.889; p = 0.009) than ΔVpeak >15% (AUROC, 0.778; p = 0.061). CONCLUSION: The ICA variability >9.85% measured via transfontanelle ultrasound is a good predictor of fluid responsiveness in infants, especially those younger than 6 months on mechanical ventilation after cardiac surgery.

Role of transesophageal echocardiography in the recurrent biatrial myxoma of uncommon origin.

After surgical excision of myxoma recurrence usually happens adjacent to the initial origin site. We report a case of recurrent myxomas in a young male patient that had biatrial recurrence with one tumor originating very unusually from the base of the anterior mitral leaflet. Intraoperative transesophageal echocardiography was instrumental in localizing the site of the origin of left atrial myxoma from the base of the anterior mitral leaflet and in detecting an additional myxoma attached to the wall of the right atrium.

Utility of Lung Ultrasound in the Estimation of Extravascular Lung Water in a Pediatric Population-A Prospective Observational Study.

OBJECTIVE: Lung ultrasound (LUS) is a promising bedside modality for the estimation of extravascular lung water index (EVLWI), but has not been validated against objective measures in children. This study aimed to investigate the correlation of LUS B-line scoring with EVLWI, thresholds indicating elevated EVLWI, and its outcome following pediatric cardiac surgery. DESIGN: Prospective observational study. SETTING: Cardiothoracic surgical intensive care unit in a tertiary care teaching hospital. PARTICIPANTS: Children younger than 12 years undergoing elective complete surgical correction of cyanotic or acyanotic congenital heart disease (Aristotle score ≤9), excluding neonates, those weighing <3.5 kg, and those with thoracic deformities, pulmonary pathology, and hemodynamic instability. INTERVENTIONS: Extravascular lung water index measurement by transpulmonary thermodilution, along with concurrent LUS B-line and Chest-X ray (CXR) scoring. MEASUREMENTS AND MAIN RESULTS: LUS B-line score had a moderate correlation with EVLWI (Pearson's correlation coefficient 0.57; 95% CI 0.44-0.69). LUS B-line scores showed acceptable discrimination only for higher thresholds of EVLWI (sensitivity 82% and 79%, respectively, for EVLWI >20 mL/kg v sensitivity and specificity 57% and 80% for EVLWI >10 mL/kg). Age, body surface area, vasoactive-inotropic score (VIS), chest X-ray score, and EVLWI but not LUS B-line score were significant predictors for duration of mechanical ventilation in this cohort. CONCLUSIONS: LUS B-line scoring has limited utility in semiquantitative estimation of EVLWI at lower thresholds of EVLWI in pediatric cardiac surgical patients. It may have better discrimination and acceptable sensitivity and specificity at higher thresholds of EVLWI. Contrasting with multiple reports of clinical utility, these results call for wider evaluation of LUS and its clinical modifiers like age, pathology, and pretest probability in estimation of EVLWI.

Role of Lung Ultrasound in the Detection of Postoperative Pulmonary Complications in Pediatric Patients: A Prospective Observational Study.

OBJECTIVE: To evaluate the incremental benefit of lung ultrasound (LUS) over clinical examination and chest x-rays (CXR) together (clinico-radiologic examination) for the diagnosis of postoperative pulmonary complications (PPC). DESIGN: Prospective observational study. SETTING: Tertiary care center. PARTICIPANTS: One hundred children after corrective congenital cardiac surgery with left-to-right shunts. INTERVENTION: Participants were independently evaluated with clinico-radiologic examination by the treating team, as well as LUS by an investigator at 12, 24, 48, and 72 hours after surgery. After recording the diagnoses, the LUS findings were disclosed to the treating team and a final diagnosis was made. CXR scores and LUS scores were evaluated for their ability to predict PPC. MEASUREMENTS AND MAIN RESULTS: A total of 34 cases of PPCs were observed. Of these, 32 each were detected by clinico-radiologic examination and LUS alone. Addition of LUS improved total number of PPCs detected in the early postoperative period but not in the late postoperative period. Preoperative and early postoperative LUS scores were superior to CXR scores in predicting occurrence of PPC (area under receiver operating characteristics curve [AUROC] 0.920 v 0.732; p < 0.001 preoperatively; AUROC 0.987 v 0.858, p = 0.001 at 12 hours postoperatively). Multivariate analysis suggested LUS score as an independent predictor of PPC, and LUS score along with aortic cross-clamp time as independent predictors of duration of mechanical ventilation and intensive care unit stay. CONCLUSIONS: LUS improves identification of PPC over clinico-radiologic examination in the early postoperative period. Preoperative LUS scores have better predictive ability than CXR scores for the occurrence of PPC.

Left Atrial Dissection and Rupture Following Excision of Left Atrial Myxoma: Role of Transesophageal Echocardiography.

Left atrial mass after excision of a left atrial myxoma may occur due to residual or additional masses, such as biatrial or multicentric myxomas and inverted left atrial appendage. In this E-challenge, the authors present a case where intraoperative transesophageal echocardiography allowed visualization of a left atrial mass after excision of a left atrial myxoma. Detailed examination demonstrated that the mass was due to left atrial dissection that progressed to rupture, allowing its early detection and repair. A high index of suspicion, as well as coordination between the surgeon and the perioperative echocardiographer, played a crucial role in the detection and management of this complication.

Emergency valve preserving ascending aorta replacement following iatrogenic right coronary artery dissection: A life-saving procedure.

Iatrogenic aortocoronary dissection is a rare but potentially fatal complication of coronary catheterizations. Although the incidence is comparatively low, dissection often leads to procedure failure with increased risk of myocardial infarction and death. Iatrogenic aortocoronary dissection is principally caused by disruption of intima at the ostia of the right or left coronary artery during interventional procedures and appears as luminal filling defects, the persistence of contrast or intimal tear outside the coronary lumen. We present a case of right coronary artery dissection leading to type-A aortic dissection suffered during diagnostic coronary catheterization. This required emergency supracoronary replacement of the ascending aorta with an aortic interposition tube graft and venous grafts to coronary arteries.

Absent right superior vena cava with left superior vena cava draining into unroofed coronary sinus with common atrium in a child with an atrioventricular septal defect.

The association of absent right superior vena cava and persistent left superior vena cava draining into unroofed coronary sinus with common atrium and the atrioventricular septal defect is an extremely rare form of the congenital cardiac disorder with only one case reported so far, hence, can be missed preoperatively if not carefully looked for. Failure to detect absent right superior vena cava beforehand may otherwise pose difficulties in carrying out invasive surgical or medical interventions.

Dextrocardia, situs solitus, inlet ventricular septal defect (VSD), and iatrogenic tricuspid regurgitation (TR)-A surgical perspective.

Dextrocardia with situs solitus is a rare congenital anomaly, often associated with intra- or extracardiac malformations. A clear understanding of the spatial orientation of the chambers of the heart for planning surgical approach, is imperative. Access to the right side of the heart, especially for repair of the tricuspid valve can be challenging. We describe a case of dextrocardia, situs solitus, inlet ventricular septal defect (VSD) with iatrogenic tricuspid regurgitation (TR) in an adult patient, highlighting the surgical aspects essential for a successful outcome.

Comparison between computerized tomography-guided bronchial width measurement versus conventional method for selection of adequate double lumen tube size.

Background: Selection of adequate size double lumen tube (DLT) is complicated by marked inter-individual variability in morphology and dimensions of tracheobronchial tree. Computerized tomography (CT)-guided left bronchus width measurement has been used to predict adequate size DLT in European and Singapore population; however, no such data exist for Indian population who are racially different. We compared the effect of DLT size selection based on CT-guided bronchial width measurement to the conventional method of DLT selection on the adequacy of both lungs isolation and on the safety margin of right-sided DLT. Methods: Fifty-five adults scheduled to undergo thoracotomy were enrolled in this prospective observational study. An appropriate size left- or right-sided DLT with outer diameter 0.5-1 mm smaller than the CT-measured bronchial width was selected for the isolation of lungs. Adequacy of separation was checked using fiberoptic bronchoscope. The safety margin of selected right-sided DLT size was calculated from CT-measured right upper lobe bronchus width and diameter of right upper lobe ventilation slot of the DLT. Results: Adequate separation of lungs was achieved in 92.7% of studied population, 90.9% in males, and 95.4% in females. Among these, 54.9% patients required different sized DLT as compared to conventional method. Overall safety of margin of right-sided DLTs was comparable between two methods of DLT selection (median [IQR] 4.8 (3.5-6.8) vs. 6.59 (3.5-7.8), P = 0.317). DLT size with adequate isolation of lung correlated with height, tracheal width (TW) on chest X-ray, and age of the patients. A formula to calculate DLT size based on these variable was derived. Conclusion: CT-measured bronchial width predicts the appropriate DLT size better than conventional method. In the absence of CT scan facility, patient height, age, and chest X-ray TW may be used to predict DLT size with reasonable accuracy.

Role of perioperative echocardiography in repair of incomplete shone complex: A case series.

Multilevel obstruction of left-sided heart structures was originally characterized by Shone et al. The formulation of an appropriate operative strategy remains challenging and needs to be individualized for this complex subset of patients. Intraoperative transesophageal echocardiography (TEE) not only helps in delineating spatial anatomy but also reveals associated anomalies that help in decision-making regarding operative strategies for these patients. Here, we discuss five such cases of Shone's anomaly presenting at varied age group with different associated anomaly in which intraoperative TEE played a pivotal role in the management.

Early thrombolysis is associated with decreased operative mortality in postinfarction ventricular septal rupture.

BACKGROUND: Post myocardial infarction ventricular septal rupture (PMI-VSR) is a dreaded mechanical complication of acute coronary syndromes. Given that surgical mortality approaches 50%, it is pragmatic that the risk factors for mortality and outcomes after surgical correction of PMI- VSR are carefully scrutinized. METHODS: We performed a single-center, retrospective cohort study of 35 patients presenting for surgical closure of post myocardial infarction ventricular septal rupture over six years. We reviewed patient characteristics, clinical, echocardiographic, angiographic and perioperative risk factors which may affect mortality after surgical repair of PMIVSR and 30 day and one year mortality rates of these patients. Univariate and multivariate logistic and cox proportional hazard regression analysis was used to identify predictors of operative and overall mortality. Long term survival was presented with Kaplan-Meier Survival Curve. RESULTS: Sixteen patients (46%) were in cardiogenic shock. Concomitant coronary artery bypass grafting (CABG) was done in 22 patients (63%) but did not influence survival. Preoperative thrombolysis was done in 12 patients (34%) out of which 10 (53%) survived Operative mortality was 46% and one-year mortality was 49%. Multivariate analysis identified preoperative thrombolysis: Hazards ratio, 0.12; 95% CI, 0.02-0.61; p value of 0.01, as significant independent predictor of survival in PMIVSR cohort. CONCLUSIONS: Preoperative thrombolysis is associated with decreased odds of operative and overall mortality after surgical repair in PMIVSR patients.

Anthryl Benzothiazolium Molecular Rotor-Based Turn-On DNA Probe: Detailed Mechanistic Studies.

An efficient turn-on fluorescence probe for biomolecules not only helps in its sensitive detection but is also useful to understand the different interactions that are operating between biomolecules and probes. Polycyclic aromatic molecules are known to be strong interacting ligand for DNA and extensively studied as a model cancer drug. However, these molecules show large decrease in their emission intensity, i.e., a turn-off probe for DNA. In the present work, we have synthesized a benzothiazole-based anthracene derivative and studied its interaction with a natural DNA with the aim of having a turn-on DNA probe with a polycyclic aromatic moiety. Our detailed spectroscopic studies show that the new probe strongly interacts with DNA molecules and results in a significant increase in its emission yield. Time-resolved studies show a large increase in probe's excited-state lifetime in DNA solution. Detailed experiments have been performed to understand its mode of interaction with DNA molecules. The mode of interaction has also been supported by the blind molecular docking studies. Further, the viscosity-dependent photophysical properties and detailed quantum chemical calculations confirm that the new probe belongs to molecular rotor class of molecules. Association with DNA molecules results in a significant retardation in the nonradiative deactivation process due to the torsional motion in the excited state of the probe and leads to a significant increase in its emission yield. Thus, due its molecular rotor nature, despite with a turn-off fluorophore unit, anthracene, the new probe, acts as a sensitive turn-on fluorescence probe for DNA molecules.

The processing and heterostructuring of silk with light.

Spider silk is a tough, elastic and lightweight biomaterial, although there is a lack of tools available for non-invasive processing of silk structures. Here we show that nonlinear multiphoton interactions of silk with few-cycle femtosecond pulses allow the processing and heterostructuring of the material in ambient air. Two qualitatively different responses, bulging by multiphoton absorption and plasma-assisted ablation, are observed for low- and high-peak intensities, respectively. Plasma ablation allows us to make localized nanocuts, microrods, nanotips and periodic patterns with minimal damage while preserving molecular structure. The bulging regime facilitates confined bending and microwelding of silk with materials such as metal, glass and Kevlar with strengths comparable to pristine silk. Moreover, analysis of Raman bands of microwelded joints reveals that the polypeptide backbone remains intact while perturbing its weak hydrogen bonds. Using this approach, we fabricate silk-based functional topological microstructures, such as Mobiüs strips, chiral helices and silk-based sensors.

Silicone tracheobronchial stent: A rare cause for bronchoesophageal fistula and distortion of airway anatomy.

Silicone tracheobronchial stents are being increasingly used in a large number of patients for the treatment of tracheal stenosis. One very rare complication due to tracheobronchial stenting is bronchoesophageal fistula (BEF), which has been associated with the use of metallic stents. We report intraoperative management of a patient undergoing repair of a BEF, following previous insertion of a silicone Y-stent that is soft in texture and has not been implicated for this complication till date. In addition, misalignment of this silicone tracheobronchial Y-stent resulted in a tracheal mucosal bulge proximal to the stent that vanished after its removal.