Prediction of fluid responsiveness following liver compression in pediatric patients with single ventricle physiology.

INTRODUCTION: The role of liver compression in predicting fluid responsiveness in children with a single ventricle has never been evaluated. The purpose of this study was to assess whether blood pressure changes during liver compression predict fluid responsiveness in children with single ventricle physiology. METHODS: This prospective, interventional study included children aged 3 months to 5 years who underwent surgery for bidirectional cavopulmonary shunt or extracardiac Fontan operation. Before fluid loading, the right upper abdomen was compressed at 30 mmHg for 10 s, and changes in the blood pressure waves were recorded before administering 10 ml kg-1 of crystalloid solution. Systolic arterial pressure, diastolic arterial pressure, central venous pressure, pleth variability index, respiratory variation in aortic blood flow peak velocity, and stroke volume were measured before and after fluid loading. A volume responder was defined as a patient with >15% increase in stroke volume index. RESULTS: Thirty patients underwent bidirectional cavopulmonary shunt (15 responders and 15 non-responders), and 32 underwent Fontan surgery (17 responders and 15 non-responders). In children with bidirectional cavopulmonary shunt, Δsystolic arterial pressure > 8 mmHg (sensitivity 76.9% and specificity 93.3%), Δdiastolic arterial pressure > 7 mmHg (sensitivity 69.2% and specificity 93.3%), and Δmean arterial pressure > 7 mmHg (sensitivity 69.2% and specificity 100%) during liver compression predicted fluid responsiveness. The areas under the receiver operating characteristic curves of Δsystolic arterial pressure, Δdiastolic arterial pressure, and Δmean arterial pressure were 0.928, 0.859, and 0.874 (all p < .001). In children who underwent Fontan surgery, only Δsystolic arterial pressure > 16 mmHg was predictive of fluid responsiveness (sensitivity of 41.2% and specificity of 100%), with the areas under the receiver operating characteristic curves curve of 0.786 (p < .001). Pleth variability index and respiratory variation in aortic blood flow peak velocity had no predictive value for fluid responsiveness after both types of surgeries. DISCUSSION: In BCPS patients, liver compression increases the inferior vena cava flow which directly leads to an increase in preload. On the other hand, blood flow from the liver drains directly into the pulmonary arteries in Fontan circulation. Because of this characteristics for preload determination, the clinical application of liver compression to monitor hemodynamic changes might be more useful in patients with bidirectional cavopulmonary shunt than those with Fontan circulation. CONCLUSION: Increase in blood pressure induced by liver compression is predictive of fluid responsiveness in children with single ventricle physiology.

The Prognostic Role of Right Ventricular Stroke Work Index during Liver Transplantation.

Right heart-associated hemodynamic parameters including intraoperative pulmonary vascular resistance (PVR) were reported to be associated with patient survival after liver transplantation. We investigated whether intraoperative stroke work indexes of both ventricles could have a better prognostic value than PVR. We reviewed 683 cases at a tertiary care academic medical center. We collected intraoperative variables of baseline central venous pressure, baseline right ventricle end-diastolic volume, mixed venous oxygen saturation, intraoperative PVR and right and left ventricular stroke work indexes. Time-weighted means or area under the curve of intraoperative right and left ventricular stroke work indexes were calculated as exposure variables. One-year all-cause mortality or graft failure was our primary outcome. Cox proportional hazard regression analysis was performed to evaluate the association between exposure variables and one-year all-cause mortality or graft failure. Kaplan-Meier survival curve analysis of our primary outcome was performed for different time-weighted mean ventricular stroke work index groups. Cubic spline curve analysis was performed to evaluate the linear relationship between our exposure variables and primary outcome. Time-weighted mean right ventricular stroke work index was significantly associated with one-year all-cause mortality or graft failure (hazard ratio 1.21, 95% confidence interval (CI) 1.12-1.36, p < 0.001). However, there was no significant association between time-weighted mean left ventricular stroke work index, time-weighted mean PVR, PVR at the end of surgery and one-year mortality. Area under the curve of right ventricular stroke work index was also significantly associated with one-year mortality or graft failure (hazard ratio 1.24, 95% CI 1.15-1.37, p < 0.001). Kaplan-Meier survival curve analysis showed a significant difference in the survival between different mean right ventricular stroke work index groups (Log-rank test: p = 0.002). Cubic spline function curve showed the gradual increase in the risk of mortality with a positive slope with time-weighted mean right ventricular stroke work index. In conclusion, intraoperative elevated right ventricular stroke work index was significantly associated with poor patient or graft survival after liver transplantation. Intraoperative right ventricular stroke work index could be an intraoperative hemodynamic goal and prognostic marker for mortality after liver transplantation.

Effect of Perioperative Subglottic Secretion Drainage on Ventilator-Associated Pneumonia After Cardiac Surgery: A Retrospective, Before-and-After Study.

OBJECTIVES: Although postoperative subglottic secretion drainage prevents ventilator-associated pneumonia (VAP) after cardiac surgery, its role during the perioperative period is unclear. For the present study, the effect of subglottic secretion drainage during and after cardiac surgery on postoperative VAP was investigated. DESIGN: Retrospective, single-center, before-and-after study. SETTING: Perioperative care of cardiac surgical patients in a tertiary university hospital. PARTICIPANTS: Adult patients who underwent cardiac surgery from January 2013-December 2018. INTERVENTIONS: Conventional and subglottic suctioning endotracheal tubes were used in the control and intervention groups before and after a change in institutional policy, respectively. In the intervention group, subglottic secretion drainage was performed continuously during surgery and intermittently after surgery. MEASUREMENTS AND MAIN RESULTS: The risk of postoperative VAP, identified by the National Healthcare Safety Network surveillance definition algorithm, was compared by weighted logistic regression. Logistic regression analyses, with propensity score matching and inverse probability weighting, also were performed. A total of 2,576 patients were analyzed (control [n = 2108]; intervention [n = 468]). Postoperative VAP occurred less frequently in the intervention group (1/468 [0.2%]) compared with the control group (30/2,108 [1.4%]). In the multivariate weighted logistic regression analysis, the risk of VAP after cardiac surgery was significantly lower in the intervention group than in the control group (odds ratio 0.29; 95% confidence interval 0.14-0.58). Similar results were obtained in multivariate analyses after propensity score matching (odds ratio 0.04; 95% confidence interval 0.01-0.14) and inverse probability weighting (odds ratio 0.16; 95% confidence interval 0.05-0.42). CONCLUSIONS: Routine perioperative subglottic secretion drainage using subglottic suctioning endotracheal tubes in patients undergoing cardiac surgery was associated with a reduction in the risk of VAP after surgery.

Effect of spontaneous breathing on atelectasis during induction of general anaesthesia in infants: A prospective randomised controlled trial.

BACKGROUND: Atelectasis occurs commonly during induction of general anaesthesia in children, particularly infants. OBJECTIVES: We hypothesised that maintaining spontaneous ventilation can reduce atelectasis formation during anaesthetic induction in infants. We compared spontaneous ventilation and manual positive-pressure ventilation in terms of atelectasis formation in infants. DESIGN: Randomised controlled study. SETTING: Single tertiary hospital in Seoul, Republic of Korea, from November 2018 to December 2019. PATIENTS: We enrolled 60 children younger than 1 year of age undergoing general anaesthesia, of whom 56 completed the study. Exclusion criteria were history of hypoxaemia during previous general anaesthesia, development of a respiratory tract infection within 1 month, current intubation or tracheostomy cannulation, need for rapid sequence intubation, preterm birth, age within 60 weeks of the postconceptional age and the presence of contraindications for rocuronium or sodium thiopental. INTERVENTION: Patients were allocated randomly to either the 'spontaneous' group or 'controlled' group. During preoxygenation, spontaneous ventilation was maintained in the 'spontaneous' group while conventional bag-mask ventilation was provided in the 'controlled' group. After 5 min of preoxygenation, a lung ultrasound examination was performed to compare atelectasis formation in the two groups. RESULTS: Atelectasis after preoxygenation was seen in seven (26.9%) of 26 patients in the 'spontaneous' group and 22 (73.3%) of 30 patients in the 'controlled' group (P = 0.001). The relative risk of atelectasis in the 'spontaneous' group was 0.39 (95% CI 0.211 to 0.723). Regarding ultrasound pictures of consolidation, the total score and sum of scores in the dependent regions were significantly lower in the 'spontaneous' group than in the 'controlled' group (P = 0.007 and 0.001, respectively). CONCLUSION: Maintaining spontaneous ventilation during induction of general anaesthesia has a preventive effect against atelectasis in infants younger than 1 year of age, particularly in the dependent portions of the lungs. TRIAL REGISTRATION: Clinicaltrials.gov (identifier: NCT03739697).

General Anesthetic Agents and Renal Function after Nephrectomy.

The association between the choice of general anesthetic agents and the risk of acute kidney injury (AKI) and long-term renal dysfunction after nephrectomy has not yet been evaluated. We reviewed 1087 cases of partial or radical nephrectomy. The incidence of postoperative AKI, new-onset chronic kidney disease (CKD) and CKD upstaging were compared between general anesthetic agent groups (propofol, sevoflurane, and desflurane). Four different propensity score analyses were performed to minimize confounding for each pair of comparison (propofol vs. sevoflurane; propofol vs. desflurane; sevoflurane vs. desflurane; propofol vs. volatile agents). Study outcomes were compared before and after matching. Kaplan-Meier survival curve analysis was performed to compare renal survival determined by the development of new-onset CKD between groups up to 36 months after nephrectomy. Propofol was associated with a lower incidence of AKI (propofol 23.2% vs. sevoflurane 39.5%, p = 0.004; vs. propofol 21.0% vs. desflurane 34.3%, p = 0.031), a lower incidence of CKD upstaging (propofol 27.2% vs. sevoflurane 58.4%, p < 0.001; propofol 32.4% vs. desflurane 48.6%, p = 0.017) and better three-year renal survival after nephrectomy compared to sevoflurane or desflurane group (Log-rank test propofol vs. sevoflurane p < 0.001; vs. desflurane p = 0.015) after matching. Propofol was also associated with a lower incidence of new-onset CKD after nephrectomy compared to sevoflurane after matching (p < 0.001). There were no significant differences between sevoflurane and desflurane. However, subgroup analysis of partial nephrectomy showed a significant difference only in CKD upstaging. In conclusion, propofol, compared to volatile agents, could be a better general anesthetic agent for nephrectomy to attenuate postoperative renal dysfunction. However, limitations of the retrospective study design and inconsistent results of the subgroup analysis preclude firm conclusions.