Utility of portal vein pulsatility fraction in patients undergoing corrective surgery for tetralogy of Fallot.

BACKGROUND: Right ventricle dysfunction is common after corrective surgery for tetralogy of Fallot and is associated with significant morbidity and mortality. We aimed to determine whether an increased portal vein pulsatility fraction (PVPF) was associated with worse clinical outcomes. METHODS: In a prospective, observational, single-centre study, PVPF and other commonly used parameters of right ventricle function were assessed in patients of all ages undergoing corrective surgery for tetralogy of Fallot intraoperatively, with transesophageal echocardiography, before and after bypass, and post-operatively, with transthoracic echocardiography, at days 1, 2, at extubation, and at ICU discharge. The correlation was tested between PVPF and mechanical ventilation duration, prolonged ICU stay, mortality, and right ventricle function. RESULTS: The study included 52 patients, and mortality was in 3 patients. PVPF measurement was feasible in 96% of the examinations. PVPF in the immediate post-operative period had sensitivity of 73.3% and a specificity of 74.3% in predicting the occurrence of the composite outcome of prolonged mechanical ventilation, ICU stay, or mortality. There was a moderate negative correlation of PVPF with right ventricle fractional area change and right ventricle global longitudinal strain (r = -0.577, p < 0.001 and r = 0.465, p < 0.001, respectively) and a strong positive correlation with abnormal hepatic vein waveform (rho = 0.749, p < 0.001). CONCLUSION: PVPF is an easily obtainable bedside parameter to assess right ventricular dysfunction and predict prolonged mechanical ventilation, prolonged ICU stay, and mortality.

Biochemical Predictors of Acute Kidney Injury in Critically Ill COVID-19 Patients.

It is estimated that 50% of patients with coronavirus disease 2019 (COVID-19) have varying degrees of renal involvement. In this clinical biomarker development research, we examined in a retrospective study design the temporal changes in biochemical laboratory parameters in relation to the development of acute kidney injury (AKI). In a sample of 399 patients admitted from May 2020 to May 2021 to a tertiary health care intensive care unit (ICU), the incidence of AKI was 27.3%, and the median time to AKI was on 7th day of ICU admission. Most common etiology of AKI was kidney hypoperfusion. Within 72 h of developmental of low blood pressure, 63.76% developed AKI. The likelihood of AKI was higher in those with elevated serum ferritin, aspartate transaminase, and thrombocytopenia (low platelet count). A cutoff value of 750.3 ng/mL [area under the ROC curve (AUC) = 0.777] for serum ferritin, and 40.05 U/L for alanine aminotransferase (AUC = 0.677) 1 day before development of AKI displayed, respectively, a sensitivity of 76.2% and 64.3%, whereas the specificity was 69.5% and 64.1%, respectively, for these two biochemical predictors. A cutoff value of platelets (152.50 × 109/L [AUC = 0.75]) measured 4 days before development of AKI, displayed 83.3% sensitivity and 16.4% specificity. Taken together, our study thoroughly examined the temporal association of various clinical and laboratory parameters with AKI and prediction models were developed as per results of the time series data. These observations in a tertiary health care setting contribute to ongoing efforts for biomarker discovery and development using routine biochemical tests so as to forecast AKI in patients with COVID-19.

Development of a cost-effective ex vivo lung perfusion system for lung transplantation in India.

Background & objectives: Standard donor lung preservation with cold flush and storage allows up to six hours between retrieval of lungs from the donor and transplantation in the recipient. Ex vivo lung perfusion (EVLP) systems mimic physiological ventilation and perfusion in the donor lungs with potential for prolonged lung preservation and donor lung reconditioning. In this study, it was aimed to perform EVLP on discarded donor lungs using a locally developed EVLP system. Methods: Equipment that are routinely used for cardiac surgeries were collected and a functional EVLP system was assembled. This system was used on five pairs of lungs retrieved from brain-dead organ donors. The lungs were ventilated and pulmonary circulation was continuously perfused with a solution containing oxygen and nutrients for four hours. The system was tested without red blood cells (RBCs) added to the solution (acellular group; n=3; A1, A2 and A3) and also with RBCs added to the solution (cellular group; n=2; C1 and C2). Results: The EVLP system was successfully used in four (A1, A2, A3 and C2) of the five lung pairs. Mechanical and gas exchange functions of the lungs were preserved in these lung pairs. One lung pair (C1) worsened and developed pulmonary oedema. Histopathological examination of all five lung pairs was satisfactory at the end of the procedure. Major challenges faced were leakage of solution from the system and obstruction to drainage of RBCs containing solution from the lungs. Interpretation & conclusions: The results of the present study suggest that, it is possible to maintain the lungs retrieved for transplantation in a physiological condition using a locally prepared EVLP system and a solution without RBCs.

Mortality Prediction of COVID-19 Patients at Intensive Care Unit Admission.

Background Coronavirus-2019 (COVID-19) patients admitted to the intensive care unit (ICU) have mortality rates between 30%-50%. Identifying patient factors associated with mortality can help identify critical patients early and treat them accordingly. Patients and methods In this retrospective study, the records of patients admitted to the COVID-19 ICU in a single tertiary care hospital from April 2020 to September 2020 were analysed. The clinical and laboratory parameters between patients who were discharged from the hospital (survival cohort) and those who died in the hospital (mortality cohort) were compared. A multivariate logistic regression model was constructed to identify parameters associated with mortality.  Results A total of 147 patients were included in the study. The age of the patients was 55 (45, 64), median (IQR), years. At admission, 23 (16%) patients were on mechanical ventilation and 73 (50%) were on non-invasive ventilation. Sixty patients (40%, 95% CI: 32.8 to 49.2%) had died. Patients who died had a higher Charlson comorbidity index (CCI): 3 (2, 4) vs. 2 (1, 3), p = 0.0019, and a higher admission sequential organ failure assessment (SOFA) score: 5 (4, 7) vs. 4 (3, 4), p < 0.001. Serum urea, serum creatinine, neutrophils on differential leukocyte count, neutrophil to lymphocyte ratio (N/L ratio), D-dimer, serum lactate dehydrogenase (LDH), and C-reactive protein were higher in the mortality cohort. The ratio of partial pressure of arterial oxygen to fraction of inspired oxygen, platelet count, lymphocytes on differential leukocyte count, and absolute lymphocyte count was lower in the mortality cohort. The parameters and cut-off values used for the multivariate logistic regression model included CCI > 2, SOFA score > 4, D-dimer > 1346 ng/mL, LDH > 514 U/L and N/L ratio > 27. The final model had an area under the curve of 0.876 (95% CI: 0.812 to 0.925), p < 0.001 with an accuracy of 78%. All five parameters were found to be independently associated with mortality.  Conclusions CCI, SOFA score, D-dimer, LDH, and N/L ratio are independently associated with mortality. A model incorporating the combination of these clinical and laboratory parameters at admission can predict COVID-19 ICU mortality with good accuracy.

Intraoperative transesophageal echocardiography: A complement to 18F-fluorodeoxyglucose positron emission tomography-computed tomography in localizing pacemaker lead endocarditis.

Lead endocarditis (LE) is a serious complication of permanent trans-venous pacing. Localizing LE may be challenging with conventional imaging modalities. 2-deoxy-2-[fluorine-18] fluoro-D-glucose positron emission tomography-computed tomography (FDG PET/CT) has recently emerged as a promising tool in the diagnosis of LE particularly in cases with normal echocardiographic imaging findings and/or negative blood culture. However, this technique is associated with some drawbacks. Knowledge of these drawbacks and correlating its limitations with other imaging modality is essential for the echocardiographer while evaluating such patient. We report a case where transesophageal echocardiography was complementary to FDG PET/CT in the diagnosis and localization of vegetation over pacemaker leads during intraoperative period.

ST Segment-Elevation Myocardial Ischemia After Arterial Switch Operation due to Pericardial Drain Placement: A Case Report.

Myocardial ischemia postarterial switch operation has been reported extensively in the literature and has been almost exclusively ascribed to issues related to coronary artery translocation. Here, we report a case of a 5-week-old child with D-transposition of the great arteries who underwent an arterial switch operation and developed myocardial ischemia after pericardial drain placement, as evidenced by significant ST segment elevation and abnormal regional cardiac wall motion. The ST segment and cardiac wall motion improved once the drain was withdrawn from the pericardium and placed in the retrosternal space. Few reports in the literature describe this complication, particularly in pediatric patients.

Failure of Pulse Oximetry and Cooximetry as Monitors in a Patient With Hemoglobin MIwate: A Case Report.

We present the perioperative details of a 2-year-old child scheduled for cleft palate repair. Low pulse oximetry readings after induction of anesthesia and before surgery led to the diagnosis of HbMIwate, a rare congenital methemoglobinemia due to mutation in the α-globin gene. We explored the utility of noninvasive cooximetry to monitor methemoglobin and oxygenation during anesthesia and found that noninvasive cooximetry is not useful to monitor oxygenation or to detect the percentage of methemoglobin arising from congenital variants like HbMIwate.