Effect of Equal Ratio Ventilation on Respiratory Mechanics and Oxygenation During Volume-Controlled Ventilation in Pediatric Patients

Purpose: Children have few small alveoli, which reduce lung compliance; in contrast, their cartilaginous rib cage makes their chest wall highly compliant. This combination promotes lung collapse. Prolonged inspiratory to expiratory (I:E) ratio ventilation is used to optimize gas exchange and respiratory mechanics in surgery. However, the optimal ratio is unclear in children. We hypothesized that, compared to a 1:2 I:E ratio, a 1:1 I:E ratio would improve dynamic compliance and oxygenation, and affect the peak airway pressure in pediatric patients undergoing surgery. Materials and methods: Forty-eight patients aged ≤6 years who were scheduled to undergo surgery under general anesthesia with an arterial line were randomly allocated to receive 1:1 (group 1:1) or 1:2 (group 1:2) I:E ratio ventilation. Airway pressure, respiratory system compliance, and arterial blood gas analyses were compared between groups immediately after induction (T0), 30 min after induction (T1), 60 min after induction (T2), immediately after surgery (T3), and on arrival at the post-anesthesia care unit (T4). Results: Peak and plateau airway pressures were significantly lower in group 1:1 than in group 1:2 at T1 (p=0.044 and 0.048, respectively). The dynamic and static compliances were significantly higher in group 1:1 than in group 1:2 at T1 (p=0.044 and 0.045, respectively). However, the partial pressure of oxygen did not significantly differ between groups. Conclusion: Compared to a 1:2 I:E ratio, a 1:1 I:E ratio improved dynamic compliance and lowered the peak airway pressure without complications in pediatric patients. Nevertheless, our results do not support its use solely for improving oxygenation.ope

Prognostic Value of Serum Albumin in Aortic Aneurysm Patients Undergoing Graft Replacement of Ascending Aorta and Aortic Arch

Background: Hypoalbuminemia is a marker of poor overall health with influences from protein energy malnutrition, systemic inflammation and hepatic and renal disease. Albumin has been reported to have a prognostic impact in various cohorts. This study investigated whether preoperative serum albumin levels could be used to predict mortality in patients with aortic aneurysms undergoing graft replacement of ascending aorta and aortic arch. Methods: We retrospectively reviewed 183 patients who underwent graft replacement of ascending aorta and aortic arch between January 2010 and December 2020. The exclusion criteria included patients with traumatic aortic injuries (n=2), previous aortic repair within 6 months (n=2), ruptured aortic aneurysms (n=14), or a lack of preoperative laboratory data or medical records (n=10). The remaining 87% eligible patients were divided into two groups based on their preoperative serum albumin levels. The lower albumin group was defined as having serum albumin levels ≤3.5 g/dL, while the higher albumin group was defined as having albumin levels >3.5 g/dL. The incidence of mortality was compared between the two groups, and a logistic regression analysis was performed to evaluate the predictors of mortality. Results: The incidence of 1-year mortality was higher in the lower albumin group than in the higher albumin group (3.4% vs. 23.5%, p=0.006). The optimal cut-off value of albumin to predict 1-year mortality was 4.0 g/dL (area under the curve 0.885, 95% CI 0.821–0.949, p<0.001), with a sensitivity and specificity of 90.0% and 80.3%, respectively. Preoperative serum albumin levels (OR = 0.116, 95% CI 0.021-0.641, p=0.014) and diabetes mellitus (OR = 5.757, 95% CI 1.018-32.565, p=0.048) remained independent predictors of mortality. Conclusion: Preoperative serum albumin levels were an independent predictor of 1-year mortality after the graft replacement of ascending aorta and aortic arch. These findings underscore that the optimization of patients' nutritional status before surgery may be warranted and should be further explored in this high-risk population.ope

Prognostic impact of preoperative serum alkaline phosphatase level on a composite of morbidity and mortality after thoracic endovascular aortic repair: A retrospective study

BACKGROUND: Serum alkaline phosphatase (ALP) is related to vascular calcification and is known to have a prognostic impact in various cohorts. However, evidence in patients undergoing thoracic endovascular aortic repair (TEVAR) is lacking. Thus, we hypothesized that preoperative serum ALP level could be used for predicting adverse events after TEVAR. METHODS: We retrospectively reviewed 167 patients who underwent TEVAR between February 2013 and December 2016. Patients were classified into tertiles according to preoperative ALP level (92 IU/L). The composite of morbidity and mortality (composite MM) was defined as the presence of one or more of the following: myocardial infarction, cerebrovascular accident, dialysis requirement, pulmonary complication, infection, and mortality within 1 year after TEVAR. The incidence of composite MM was compared among the 3 tertiles, and stepwise logistic regression analysis was performed to evaluate the predictors for composite MM. RESULTS: The incidence of composite MM was 14.5% in the first tertile group, 17.9% in the second tertile group, and 35.7% in the third tertile group (P = .016). The third tertile of ALP level (odds ratio [OR] 1.766, 95% confidence interval [CI] 1.074-2.904, P = .025) and emergency TEVAR (OR 2.369, 95% CI 1.050-5.346, P = .038) remained as independent predictors of composite MM. CONCLUSIONS: Our data showed an independent relationship between high preoperative ALP levels and adverse outcomes in patients undergoing TEVAR. This finding might suggest a potential role of ALP level as a risk stratification marker.ope

Heart rate variability predicts the extent of corrected QT interval prolongation after tracheal intubation

Background:Corrected QT (QTc) interval can be modulated by sympathetic and parasympathetic balance. Tracheal intubation causes significant prolongation of the QTc interval due to sympathetic stimulation. This study was designed to elucidate the relationship between baseline autonomic nervous system activity and QTc prolongation after endotracheal intubation using heart rate variability (HRV). Methods: Sixty-six healthy patients were included and the baseline HRV data were recorded for 5 min before anesthesia. Power spectrum densities were calculated for low frequencies (LF, 0.04−0.15 Hz) and high frequencies (HF, 0.15−0.4 Hz), defined as either LF's or HF's relative part of the total power. Anesthesia was induced with sevoflurane and vecuronium was given. The QTc interval, heart rate (HR) and mean arterial pressure (MAP) were measured before induction (baseline), before laryngoscopy (pre-intubation) and immediately after the intubation (post-intubation). Results: The QTc interval change at post-intubation from baseline (ԤQTc) showed a significant negative correlation with the HF (r = 0.34, P = 0.006) and positive correlation with LF/HF ratio (r = 0.37, P = 0.005). Patients were retrospectively divided into low-HF/ LF (＜2.5, n = 44) and high-HF/LF group (＞2.5, n = 22). The ԤQTc was statistically higher in the high-LF/HF group compared to that in the low-LF/HF group (P = 0.048). The HR and MAP at baseline, pre-intubation and post-intubation were not different between two groups. Conclusions: The QTc interval prolongation after endotracheal intubation is influenced by baseline autonomic conditions and can be exaggerated in patients with activated sympathetic activity or depressed parasympathetic activity.ope

A brief cardiac arrest due to saline irrigation during surgery for infratentorial cerebellar tumor

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Efficacy of Single-Dose Dexmedetomidine Combined with Low-Dose Remifentanil Infusion for Cough Suppression Compared to High-Dose Remifentanil Infusion: A Randomized, Controlled, Non-Inferiority Trial

Background: Combination of dexmedetomidine and opioid may be an alternative to high-dose opioid in attenuating cough during emergence from anesthesia, while also reducing the adverse effects of high-dose opioid. We tested the hypothesis that a single-dose of dexmedetomidine combined with low-dose remifentanil infusion during emergence would not be inferior to high-dose remifentanil infusion alone in attenuating cough after thyroidectomy. Methods: One hundred sixty-nine patients undergoing thyroidectomy were enrolled and randomized in a 1:1 ratio into group DR or group R. Each patient received an infusion of dexmedetomidine (0.5 μg/kg) and low-dose remifentanil infusion of effect-site concentration (Ce) at 1 ng/mL or normal saline and high-dose remifentanil infusion of Ce at 2 ng/mL for 10 min at the end of surgery. Remifentanil was maintained until tracheal extubation. Primary endpoint was the severity of coughing, which was assessed for non-inferiority using a four-point scale at the time of extubation. For comparison of coughing incidence during emergence, coughing grade was also measured at three times: before extubation, at extubation, and after extubation. Time to awakening, hemodynamic and respiratory profile, pain, and postoperative nausea and vomiting were also evaluated for superiority. Results: The 95% confidence intervals for differences in cough grade during tracheal extubation were <0.9, indicating non-inferiority of the single dose of dexmedetomidine combined with low-dose remifentanil infusion. The incidence of coughing was similar in the two groups. Hemodynamic changes during tracheal extubation were attenuated, but emergence from anesthesia was delayed, in group DR. Use of rescue antiemetic was similar in both groups, but the incidence of vomiting was less in group DR. Conclusion: A single-dose of dexmedetomidine (0.5 μg/kg) combined with low-dose remifentanil infusion at 1 ng/mL of Ce during emergence from sevoflurane-remifentanil anesthesia was not inferior to high-dose remifentanil infusion alone at 2 ng/mL of Ce with regard to suppressing cough.ope

Incidence and Risk Factors of Acute Kidney Injury After Kasai Operation for Biliary Atresia: A Retrospective Study

Background: Biliary atresia is a progressive, inflammatory, and destructive pathology of the bile ducts. Patients who undergo surgery for correction of biliary atresia (Kasai operation) are at risk of acute kidney injury (AKI) because of their young age at the time of surgery, long operation time, and liver fibrosis or failure as complication of biliary atresia. Conversely, AKI is associated with poor outcomes after surgery. This study therefore aimed to evaluate the incidence, risk factors, and outcomes of AKI after Kasai operation. Methods: All consecutive patients who underwent Kasai operation between March 2006 and December 2015 in a single tertiary-care university hospital were enrolled. AKI was defined based on the Acute Kidney Injury Network criteria. Multivariate logistic regression models were used to assess risk factors for AKI. Results: One hundred sixty-six patients received Kasai operation during study period. Of these, AKI occurred in 37 of 166 patients (22.3%). In multivariate logistic regression analysis, age older than 30 days, higher preoperative estimated glomerular filtration rate, and preoperative contrast use within 7 days were associated with the development of AKI. Perioperative packed red blood cells transfusion was related to reduced occurrence of AKI. AKI was associated with longer ICU stay (OR = 1.015, p = 0.016). More patients with AKI were also found to receive additional surgery except liver transplantation within 1 year compared to those without AKI (10.8 % vs. 2.3 %, p = 0.045). Conclusions: Increased age is strongly associated with the development of AKI after Kasai operation. These findings indicate a rational basis for early corrective surgery for biliary atresia, early screening for AKI, and intervention to improve the results of Kasai operation.ope

Prognostic value of preoperative serum alkaline phosphatase for predicting 3-year mortality in patients undergoing kidney transplantation: A retrospective study

Serum alkaline phosphatase (ALP) levels are related to high-turnover bone disease and reflect vascular calcification and inflammation. ALP has been reported to have a prognostic impact in various cohorts including chronic kidney disease. This study investigated whether preoperative serum ALP level could be used for predicting mortality in patients undergoing kidney transplantation. We retrospectively reviewed 1,718 patients who underwent kidney transplantation between November 2005 and June 2017. Finally, 1,533 patients who met the inclusion criteria were classified into tertiles based on preoperative serum ALP level ( 72 IU/L). The incidence of mortality was compared among the three tertiles, and a stepwise logistic regression analysis was performed to evaluate the predictors for mortality. The incidence of 3-year mortality was the highest in the third tertile (1.0% vs. 2.5% vs. 4.4% in the first, second, and third tertile, respectively, p = 0.003). The third tertile of ALP level (odds ratio [OR] 1.855, 95% CI 1.192-2.886, p = 0.006), age (OR 1.052, 95% CI 1.022-1.082, p = 0.011), and history of hypertension (OR 0.401, 95% CI 0.210-0.765, p = 0.006) remained as independent predictors of mortality. Preoperative serum ALP level was significantly higher in the non-survivor group than in the survivor group (58.00 [44.00-76.00] vs. 75.00 [56.25-113.00], p = 0.003). The optimal cut-off value of serum ALP to predict 3-year mortality was 71 IU/L (area under the curve 0.636, 95% CI 0.554-0.719, p = 0.003). Therefore, preoperative serum ALP level was an independent predictor of 3-year mortality in patients undergoing kidney transplantation.ope

Association of Pre- and Post-Donation Renal Function with Midterm Estimated Glomerular Filtration Rate in Living Kidney Donors: A Retrospective Study

Purpose: The estimated glomerular filtration rate (eGFR) at 6 months after donation (eGFR6m) is strongly associated with the risk of end-stage renal disease in living kidney donors. This study aimed to investigate the incidence of eGFR6m <60 mL/min/1.73 m2(eGFR6m <60) and identify the risk factors that can predict the occurrence of eGFR6m <60 in living kidney donors. Materials and Methods: Living kidney donors who underwent nephrectomy at Severance Hospital between January 2009 and December 2019 were identified. We excluded 94 of 1233 donors whose creatinine values at 6 months after donation were missing. The risk factors for eGFR6m <60 were assessed using multivariate regression analysis. The optimal cutoff points for candidate risk factors for predicting eGFR6m <60 occurrence were determined using the Youden index. Results: The eGFR6m <60 occurred in 17.3% of the participants. Older age (≥44 years), history of hypertension, lower preoperative eGFR (<101 mL/min/1.73 m2), and degree of increase in creatinine levels on postoperative day 2 compared to those before sur gery (ΔCr2_pre) (≥0.39 mg/dL) increased the risk of eGFR6m <60. The addition of ΔCr2_pre to preoperative eGFR yielded a higher predictive accuracy for predicting eGFR6m <60 than that with preoperative eGFR alone {area under the receiver operating charac teristic curve=0.886 [95% confidence interval (CI), 0.863–0.908] vs. 0.862 (95% CI, 0.838–0.887), p<0.001}. Conclusion: The incidence of eGFR6m <60 was 17.3%. Older age, lower preoperative eGFR, history of hypertension, and greater ΔCr2_pre were associated with the occurrence of eGFR6m <60 after living donor nephrectomy. The combination of preoperative eGFR and ΔCr2_pre showed the highest predictive power for eGFR6m <60.ope

Kidney Function in Living Donors Undergoing Nephrectomy by Sevoflurane or Desflurane Anesthesia

PURPOSE: Although there is no clinical evidence of nephrotoxicity with the volatile anesthetics currently used in general anesthesia, a better agent should be needed in terms of preserving postoperative renal function in living kidney donors who have only single remaining kidney. The purpose of the current retrospective, single-center study was to evaluate and compare renal function of living kidney donors after nephrectomy under either sevoflurane or desflurane anesthesia. MATERIALS AND METHODS: From January 2006 through December 2011, a total of 228 donors undergoing video assisted minilaparotomy surgery nephrectomy for kidney donation were retrospectively enrolled in the current study. The donors were categorized into a sevoflurane group or desflurane group based on the type of volatile anesthetic used. We collected laboratory data from the patients preoperatively, immediately after the operation, on the first postoperative day and on the third postoperative day. We also compared renal function of the kidney donors after donor nephrectomy by comparing creatinine level and estimated glomerular filtration rate (eGFR). RESULTS: The decrease in renal function after surgery in both groups was the most prominent on the first postoperative day. There were no significant differences between the two groups in postoperative changes of creatinine or eGFR. CONCLUSION: Sevoflurane and desflurane can be used safely as volatile anesthetics in donors undergoing nephrectomy.ope