A prospective study on use of thrive (transnasal humidified rapid insufflation ventilatory exchange) versus conventional nasal oxygenation following extubation of adult cardiac surgical patients.

Background: Postoperative pulmonary complications in cardiac surgery increase mortality and morbidity. High flow nasal cannula oxygen therapy (HFNC) is one of the preventive measures to reduce the incidence of lung complications. HFNC can decrease dyspnea and improve physiologic parameters after extubation, including respiratory rate and heart rate, compared with conventional oxygen therapy. In this study, we evaluated the role of THRIVE (Transnasal Humidified Rapid Insufflation Ventilatory Exchange) after extubation. Methodology: We prospectively randomized 60 adults aged between 18 and 65 years undergoing elective cardiac surgery to either High flow oxygen therapy using THRIVE (Group A) or conventional nasal cannula (group B). Arterial paO2, paCO2, pH at three points of time i.e., 1, 2, 4 hrs after extubation were evaluated using arterial blood gas analysis. Ventilation duration, the incidence of reintubation, sedation score, mortality, and other complications were also assessed. Results: Thirty adults in each group had comparable patient characteristics. There was a statistically significant decline in paCO2 in group A at 1, 2, 4 hrs post extubation (P = 0.022, 0.02, <0.001) with a significant increase in oxygenation (P < 0.001) when compared to group B.ICU stay duration was similar between two groups. No complications were noted in both groups. Conclusion: THRIVE is safe to use following extubation in adult cardiac surgical patients.

Role of urinary PO2 analysis during conventional versus conventional and modified ultrafiltration techniques in adult cardiac surgery.

Background: Medullary hypoxia is the initial critical event for kidney injury during cardiopulmonary bypass, and therefore urinary PO2 with its potential of detecting medullary oxygenation for its management. Therefore, we tested the role of urinary PO2 in predicting kidney injury in those undergoing conventional versus combined (conventional and modified) ultrafiltration during cardiac surgery in adults. Methodology: We prospectively evaluated 32 adults between 18 and 65 years of age undergoing elective on-pump cardiac surgery with ejection fraction >35% by conventional (group C) versus combined ultrafiltration (group CM). Urine samples were analyzed for PO2 after induction, 30 min, 3 h, and 6 h post filtration along with blood urea and serum creatinine after induction, at 6 h, 24 h, and 48 h post filtration. Demographic variables, cardiopulmonary bypass duration, flow rates, inotropic score, ventilation duration, diuretic use, and intensive care unit (ICU) stay were assessed between two groups. Results: Both the groups (16 in each group) had comparable urinary PO2 after induction (P = 0.387) with significant decrease in group C at 30 min, 3 h, and 6 h post filtration (P < 0.05). There was a statistically significant increase in serum creatinine (mg/dL) at 48 h in group C compared with group CM (1.57 vs. 1.25, respectively; P ≤ 0.05). There was an increased diuretic usage and length of ICU stay in group C. Conclusion: Combined ultrafiltration technique had renoprotective effect in cardiac surgery analyzed by urinary PO2 levels.

Early prediction of acute kidney injury using serum phosphorus as a biomarker in pediatric cardiac surgical patients.

BACKGROUND: Acute kidney injury (AKI) is a strong predictor of morbidity and mortality after cardiac surgery. Lack of valid early biomarkers for predicting AKI has hampered the ability to take therapeutic measures for preventive cause. Hyperphosphatemia that occurs in AKI due to renal excretion defect was not studied in this context and could be simple marker of AKI. Therefore, we tested role of serum phosphorus in prediction of AKI as a biomarker after cardiac surgery in children. METHODOLOGY: We prospectively evaluated 51 children aged between 3 weeks and 12 years undergoing elective cardiac surgery. Serum creatinine and phosphorus were measured preoperatively and postoperatively at 24 and 48 h. As per the Kidney Disease Improving Global Outcomes criteria, patients were grouped into AKI and non-AKI on the basis of the development of AKI within 48 h postsurgery. The postoperative diagnostic performance of phosphorus thresholds was analyzed by the area under receiver operating characteristic curves (AUC-ROC). RESULTS: From 51 children included, 10 developed AKI. In AKI group, serum phosphorus increased significantly from 4.47 ± 0.43 baseline to 6.29 ± 0.32 at 24 h postsurgery (P = 0.01) while serum creatinine increased from baseline 0.33 (0.24-0.46) to 0.49 (0.26-0.91) at 24 h which is statistically insignificant (P = 0.16). ROC analysis showed that serum phosphorus at 24 h, the AUC was 0.84 with sensitivity 0.75 and specificity 0.93 for a cutoff value of 6.4 mg/dl. Whereas serum phosphorus at 48 h, the AUC was 0.86 with sensitivity 66.67% and specificity 97.62% for a cutoff value of 5.4 mg/dl. CONCLUSION: Serum phosphorus can be an alternative biomarker as early as 24 h for early prediction of AKI in pediatric cardiac surgery.