Clinical implications of hypothermic ventricular fibrillation versus beating-heart technique during cardiopulmonary bypass for pulmonary valve replacement in patients with repaired tetralogy of Fallot.

OBJECTIVES: This study aimed to compare the effects of hypothermic ventricular fibrillation and beating-heart techniques during cardiopulmonary bypass (CPB) on postoperative outcomes after simple pulmonary valve replacement in patients with repaired tetralogy of Fallot (TOF). METHODS: We retrospectively reviewed the data of 47 patients with repaired tetralogy of Fallot at a single institution, who received pulmonary valve replacement under the ventricular fibrillation or beating-heart technique without cardioplegic cardiac arrest during CPB between January 2005 and April 2015. RESULTS: The patients were divided into fibrillation (n = 32) and beating-heart (n = 15) groups. On comparing these groups, the fibrillation group had a larger sinotubular junction (27.1 ± 4.6 vs 22.1 ± 2.4 mm), had a longer operation duration (396 ± 108 vs 345 ± 57 min), required more postoperative transfusions (2.1 ± 2.6 vs 5.0 ± 6.3 units) and had a higher vasoactive-inotropic score at intensive care unit admission (8.0 vs 10, all P < 0.05). Echocardiographic data indicated that the systolic internal diameter of the left ventricle was larger in the fibrillation group than in the beating-heart group immediately after surgery and at the 1-year follow-up. Major adverse cardiac events occurred in 3 cases, all from the fibrillation group. Among 7 patients from the fibrillation group with transoesophageal echocardiography data during CPB, 6 had fully opened aortic valves during fibrillation, causing flooding into the left ventricle and left ventricle distension. CONCLUSIONS: The postoperative outcomes are worse with the ventricular fibrillation technique than with the beating-heart technique during CPB for pulmonary valve replacement in patients with repaired tetralogy of Fallot.

Determination of insertion depth of flexible laryngeal mask airway in pediatric population-A prospective observational study.

STUDY OBJECTIVE: The purpose of this study was to determine the ideal insertion depth of the flexible laryngeal mask airway (FLMA) by elucidating the relationships between insertion depth and patient's age, body weight, height, and other parameters. We also evaluated an insertion technique that uses the change in intracuff pressure for proper positioning of the FLMA in cases where it is difficult to sense resistance during FLMA insertion. DESIGN: This study was a prospective observational study. SETTING: Participants were recruited from the Seoul National University Children's Hospital. PATIENTS: We enrolled 154 children aged ≤15 years with an American Society of Anesthesiologists physical status of I or II who were scheduled for ophthalmic surgery of <2 hours duration under general anesthesia. INTERVENTIONS: After induction of general anesthesia, FLMA insertion was guided by the change in intracuff pressure, measured using a manometer. The FLMA position was assessed using a fiberoptic bronchoscope. MEASUREMENTS: The FLMA insertion depth was measured at the end of each surgical procedure. A multiple linear regression model was then created using age, height, weight, nasal-tragus length, and sternal length. MAIN RESULTS: The FLMA was successfully inserted in the first attempt in 134 patients using continuous monitoring of intracuff pressure. Using multiple linear regression analysis and the Durbin-Watson test, we found that insertion depth was best predicted by height and weight (r2=0.777), and the resulting formula was as follows: insertion depth of FLMA (cm)=7.0+0.04×height (cm)+0.05 ×weight (kg). CONCLUSIONS: The FLMA insertion depth can be calculated using height and weight. Continuous monitoring of intracuff pressure during FLMA insertion is a useful alternative insertion method in cases where resistance is difficult to sense.

Intraoperative trans-fontanellar cerebral ultrasonography in infants during cardiac surgery under cardiopulmonary bypass: an observational study.

This study was performed to evaluate the feasibility of intraoperative point-of-care trans-fontanellar cerebral ultrasonography (TFCU) to obtain blood flow velocity (BFV) reference values at the internal carotid arteries (ICAs) and peri-callosal part of the anterior cerebral artery (pACA) during pediatric cardiac surgery under cardiopulmonary bypass (CPB). TFCU was performed at three time points (after induction of anesthesia, during CPB, after CPB) in 35 infants. BFV was measured at both ICAs and pACA through the anterior fontanelle with an ultrasound sector probe. We divided patients into Group S (<5 kg, n = 16) and Group L (≥5 kg, n = 19) for comparisons according to weight. We also analyzed BFV in low cerebral regional oxygen saturation (rSO2) data. All measurements of the BFV at both the ICAs and the pACA were possible. BFVs at the ICAs were lower in Group S than in Group L at all three time points. BFVs at the pACA were similar in both groups except higher value in Group L after CPB. When the rSO2 was <50, most BFVs (14 of 15 measurements) were lower than the median BFV value during CPB. However, a low rSO2 did not always reflect low BFV before and after CPB. Point-of-care TFCU can determine BFV at the ICAs and pACA during pediatric cardiac surgery. BFV differs according to the patient's size and CPB application. TFCU can be a practical cerebral blood flow monitoring method when rSO2 changes without any specific reason in infants.ClinicalTrials.gov NCT01996020.

Critical incidents, including cardiac arrest, associated with pediatric anesthesia at a tertiary teaching children's hospital.

BACKGROUND: Analysis of critical incidents provides valuable information to improve the quality and safety of patient care. This study identified and analyzed pediatric anesthesia-related critical incidents including cardiac arrests in a tertiary teaching children's hospital. METHODS: All pediatric anesthesia-related critical incidents reported in a voluntary departmental reporting system between January 2008 and August 2013 were included in the analysis. A critical incident was defined as (i) any incident that altered patients' vital signs and affected the management of patients while they were under the care of an anesthesiologist, and (ii) human factor: where patient injury or accidents were as a result of human error. Changes in vital signs that recovered spontaneously were excluded. RESULTS: During the 6-year study period, a total of 229 critical incidents were reported from 49,373 anesthetic procedures. The most frequently reported incidents were associated with the respiratory system (55%), with tracheal tube-related events accounting for 40.9% of respiratory incidents followed by laryngospasm (17.3% of respiratory incidents). Cardiac arrest occurred in 42 cases in this study (8.5 cases per 10,000 anesthetics). Cardiovascular problems were the major causes of cardiac arrest (66.7%), and incidents of cardiogenic shock and hemorrhage/hypotension contributed equally to the cardiac arrest induced by cardiovascular problems (each 16.7%). Human factor-related events accounted for 58.5% of all critical incidents of which 53.7% were respiratory events. CONCLUSION: Despite recent improvements in safety of pediatric anesthesia, many preventable factors still remain that can lead to critical incidents.

Determination of the 95% effective dose of remifentanil for the prevention of coughing during extubation in children undergoing tonsillectomy (with or without adenoidectomy).

BACKGROUND: Limited data are available regarding the 95% effective dose (ED95 ) of remifentanil to prevent the cough response during emergence from general anesthesia in children. METHODS: This study included 40 patients aged 3-12 years who underwent elective tonsillectomy with or without adenoidectomy. A predetermined remifentanil dose was infused continuously with desflurane during surgery and was continued until extubation. In the emergence period, the cough response during awake extubation was assessed to determine the remifentanil dose for the next patient. The first patient received remifentanil at the rate of 0.01 µg·kg(-1) ·min(-1) , and subsequent patients received a 0.01 µg·kg(-1) ·min(-1) higher dose than the previous patient if there was more than moderate coughing detected, and the patient after those with less than mild coughing received either the same dose (95% probability) or a 0.01 µg·kg(-1) ·min(-1) lower dose (5% probability) using the biased coin design. Times to extubation and adverse events were recorded. The ED95 was calculated using the maximum-likelihood estimation. RESULTS: The ED95 of remifentanil for preventing coughing during extubation was 0.060 µg·kg(-1) ·min(-1) (95% confidence interval, 0.037-0.068). There was moderate coughing in all groups receiving 0.01-0.06 µg·kg(-1) ·min(-1) of remifentanil, but no cough response occurred in the group receiving remifentanil 0.07 µg·kg(-1) ·min(-1) . Time to extubation was weakly correlated with remifentanil infusion rate (r = 0.331). One patient who received remifentanil 0.07 µg·kg(-1) ·min(-1) showed desaturation over 5 s immediately after extubation, but recovered after receiving 100% oxygen. CONCLUSION: The ED95 of the continuous remifentanil infusion rate was 0.060 µg·kg(-1) ·min(-1) to prevent the cough response during extubation in children after tonsillectomy.

The effect of lidocaine on apoptotic neurodegeneration in the developing mouse brain.

BACKGROUND: General anesthetics induce neuronal apoptosis in the immature brain. Regional anesthesia using local anesthetics can be an alternative to general anesthesia. Therefore, this study investigated the possible effect of lidocaine on neuronal apoptosis. METHODS: Fifty-one 7-day-old C57BL6 mice were allocated into control (group C), lidocaine (group L), lidocaine plus midazolam (group LM) and isoflurane (group I) groups. Group C received normal saline administration. Groups L and LM were injected with lidocaine (4 mg/kg, subcutaneously) only and the same dose of lidocaine plus midazolam (9 mg/kg, subcutaneously). Group I was exposed to 0.75 vol% isoflurane for 6 h. After 6 h, apoptotic neurodegeneration was assessed using caspase-3 immunostaining and terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) staining. RESULTS: For the entire brain section, neuronal cells exhibiting caspase-3 activation were observed more frequently in group I than in group C (P < 0.001). In the thalamus, apoptosis of group L was more frequent than that of group C (P < 0.001), but less freqent than that of groups LM and I (P = 0.0075 and P < 0.001, respectively). In the cortex, group I experienced more apoptosis than group L and C (all Ps < 0.001). On TUNEL staining, the difference in apoptosis between the lidocaine and control groups was marginal (P = 0.05). CONCLUSIONS: Lidocaine induced minimal apoptosis in the developing brain compared with isoflurane and lidocaine plus midazolam. However, we cannot fully exclude the possible adverse effect of subcutaneously administered lidocaine on the developing brain.

Ondansetron attenuates the activity of excitatory amino acid transporter type 3 expressed in Xenopus oocytes.

The purpose of this study was to evaluate the effect of ondansetron on excitatory amino acid transporter type 3 (EAAT3) and to elucidate the roles of protein kinase C (PKC) and phosphatidylinositol 3-kinase (PI3K) in the effect. EAAT3 was expressed in Xenopus oocytes following the injection of rat EAAT3 mRNAs. Using the two-electrode voltage clamping method, the inward currents induced by L-glutamate were measured for 1 min in the presence and absence of ondansetron (1-1000 µM). Different concentrations of L-glutamate (3-300 µM) were used to determine the kinetic characteristics of EAAT3. To identify the involvement of PKC and PI3K in the effect, oocytes were exposed to a PKC activator and to PKC inhibitors and PI3K inhibitors, and L-glutamate-induced currents were recorded. Ondansetron decreased EAAT3 activity in a dose-dependent manner. In a kinetic study, ondansetron (10 µM for 3 min) reduced Vmax, but not Km compared with the control group. The PKC activator abolished the ondansetron-induced decrease in EAAT3 activity. The PKC inhibitors (staurosporine and chelerythrine) and ondansetron had not additive or synergistic effects on EAAT3 activity. The PI3K inhibitors (wortmannin and LY294002) decreased the EAAT3 response, although there were no differences among the groups comprising ondansetron, PI3K inhibitors, and PI3K inhibitors plus ondansetron. Our results demonstrate that ondansetron attenuates EAAT3 activity and this effect seems to be mediated by PKC and PI3K.

Anesthetic management of laparoscopic pheochromocytoma excision in a patient with a Fontan circulation: a case report.

An 18-year-old male with a Fontan circulation underwent excision of a pheochromocytoma after conversion from laparoscopic surgery. The pneumoperitoneum established for laparoscopic surgery may have adverse effects on the Fontan circulation, because it increases the intra-abdominal pressure (IAP), intra-thoracic pressure, pulmonary vascular resistance, and systemic vascular resistance (SVR), and decreases cardiac preload and cardiac output. Meticulous monitoring is also required during carbon dioxide exsufflation, because a rapid decrease in IAP can provoke hemodynamic deterioration by decreasing venous return and SVR. Furthermore, catecholamines released by the pheochromocytoma can worsen the hemodynamic status of Fontan circulation during surgery. Therefore, sophisticated intraoperative anesthetic care is required during laparoscopic pheochromocytoma excision in patients with a Fontan circulation.

The effect of sevoflurane and ondansetron on QT interval and transmural dispersion of repolarization in children.

BACKGROUND: This study evaluated the prolongation of QT interval by the combination of sevoflurane and ondansetron in pediatric patients. Additionally, transmural dispersion of repolarization as interval between the peak and end of the T wave (Tp-e) and Tp-e/QT ratio was also measured to assess the risk of ventricular arrhythmia. METHODS: The 3-lead electrocardiography (ECG) in lead II was sampled at three stages: at preinduction, just before (Sevo alone) and finally, after administration of ondansetron (Sevo+Ondansetron) in 41 children aged from 3 to 12 years. The QT interval was corrected for heart rate using Bazett's formula. And, Tp-e interval was obtained, and Tp-e/QT ratio was calculated. For analysis of the changes of parameters, a repeated-measures analysis of variance was used to identify significant differences in QTc, Tp-e interval and Tp-e/QT ratio at the three epochs. RESULTS: The mean QTc at preinduction period was 413.8 (20.8) ms. The mean Sevo alone and Sevo+Ondansetron QTcs were 432.5 (28.1) and 439.2 (27.6) ms, and the differences in QTc prolongation between stages were all significant (P < 0.01). Ondansetron increased Tp-e interval significantly; however, Tp-e/QT ratio was not different among three stages. There were no ECG abnormalities such as atrial or ventricular arrhythmia and T-wave abnormality in any patient. CONCLUSIONS: Sevoflurane prolongs the QTc interval and its combination with ondansetron further increased this effect in children. However, the dispersion of ventricular repolarization was not significantly affected, and there were no adverse events such as ventricular arrhythmia in this study. The combination of sevoflurane and ondansetron may be clinically safe, but careful ECG monitoring is still advisable.

A comparative trial of the GlideScope(R) video laryngoscope to direct laryngoscope in children with difficult direct laryngoscopy and an evaluation of the effect of blade size.

BACKGROUND: GlideScope® video laryngoscope (GVL) has been proposed to be useful for airway management, but its efficacy for difficult airways has not been confirmed in pediatric patients. In this study, we evaluated the usefulness of the GVL for improving the laryngoscopic view in patients whose Cormack and Lehane grade (C&L grade) was ≥3 under direct laryngoscopy. We also assessed the effect of GVL blade size on the laryngoscopic view. METHODS: This randomized open trial was conducted in a tertiary pediatric center. Patients whose previous C&L grade was ≥3, or who were anticipated to have a difficult airway, were enrolled. The initial modified C&L grade was scored using a direct laryngoscope (DL). If the patient's C&L grade was ≥3, the laryngoscopic view was scored again using GVLw (selected based on weight) and GVLs (1 size smaller than GVLw) in random order by a single experienced anesthesiologist. All laryngoscopic views were graded both with and without the backward, upward, and right lateral displacement of the thyroid cartilage (BURP) maneuver. The primary outcome was the difference in the C&L grade between DL and GVLw, and the secondary outcome was that between GVLw and GVLs. For statistical analysis, the modified C&L grade was converted to an ordinal scale. RESULTS: Data from 23 pediatric patients were analyzed. When compared with DL, improvement of laryngoscopic view with the GVLw wa not obvious (98.3% confidence interval [CI] for differences of ordinal scale, 0-1 without BURP, P = 0.15 and 0-1 with BURP, P = 0.11). However, GVLs improved the laryngoscopic view in comparison with both DL (98.3% CI for differences, 3.5-5.0 without BURP, P = 0.00007 and 3.5-4.5 with BURP, P = 0.0001) and GVLw (98.3% CI for differences, 3.0-4.5 without BURP, P = 0.00007 and 2.5-4.0 with BURP, P = 0.0001). There was no adverse outcome during this study. CONCLUSIONS: In patients with C&L grade ≥3 under direct laryngoscopy, GVLs significantly improved the laryngoscopic view when compared with DL or GVLw. The GVLs is recommended for improving the laryngoscopic view in patients with a difficult airway.

The effect of full expiration on the position and size of the subclavian vein in spontaneously breathing adults.

BACKGROUND: If full expiration during subclavian venous cannulation increases the distance between the subclavian vein (SCV) and the pleura or increases the diameter of the vein, it might decrease the incidence of pneumothorax and/or increase the success rate of venous cannulation. In this study, we evaluated the effect of full expiration on the distance from the SCV to the pleura and on the crosssectional area (CSA) of the SCV in spontaneously breathing adults. METHODS: The distance from the inferior border of the right SCV and the pleura (SCVinf-Pleura distance), the distance from the center of the vein to the pleura (SCVcen-Pleura distance), and the CSA of the vein were measured using ultrasound at the end of inspiration and at the end of full expiration in 20 adults placed in the horizontal position. The subjects were then placed in 15° Trendelenburg tilt, and the distances and the CSA were measured again. RESULTS: The SCVcen-Pleura distances were changed minimally in the horizontal position (0.005 cm, 95% confidence interval [CI] -0.04 to 0.05) and in the Trendelenburg position (0.02 cm, 95% CI -0.005 to 0.05). The SCVinfPleura distances decreased at the end of full expiration in the horizontal position, but the change was only 0.07 cm (95% CI 0.03-0.11; P = 0.003). In the Trendelenburg position, those distances remained unchanged (0.02 cm, 95% CI -0.01 to 0.06). Compared with endinspiration, the SCV CSA after full expiration increased by at least 14% in both the horizontal position and the Trendelenburg position. CONCLUSIONS: The distance from the SCV to the pleura did not change after full expiration. However, this simple technique can still be considered during placement of subclavian catheters in spontaneously breathing patients, because it significantly enlarges the CSA of the SCV.

TRICOT encodes an AMP1-related carboxypeptidase that regulates root nodule development and shoot apical meristem maintenance in Lotus japonicus.

During the course of evolution, mainly leguminous plants have acquired the ability to form de novo structures called root nodules. Recent studies on the autoregulation and hormonal controls of nodulation have identified key mechanisms and also indicated a possible link to other developmental processes, such as the formation of the shoot apical meristem (SAM). However, our understanding of nodulation is still limited by the low number of nodulation-related genes that have been identified. Here, we show that the induced mutation tricot (tco) can suppress the activity of spontaneous nodule formation 2, a gain-of-function mutation of the cytokinin receptor in Lotus japonicus. Our analyses of tco mutant plants demonstrate that TCO positively regulates rhizobial infection and nodule organogenesis. Defects in auxin regulation are also observed during nodule development in tco mutants. In addition to its role in nodulation, TCO is involved in the maintenance of the SAM. The TCO gene was isolated by a map-based cloning approach and found to encode a putative glutamate carboxypeptidase with greatest similarity to Arabidopsis ALTERED MERISTEM PROGRAM 1, which is involved in cell proliferation in the SAM. Taken together, our analyses have not only identified a novel gene for regulation of nodule organogenesis but also provide significant additional evidence for a common genetic regulatory mechanism in nodulation and SAM formation. These new data will contribute further to our understanding of the evolution and genetic basis of nodulation.

Intraoperative plasma lactate as an early indicator of major postoperative events in pediatric cardiac patients.

Hyperlactatemia and unmeasured anions (UMA) have been suggested to be useful predictors of outcomes after pediatric cardiac surgery in the ICU. However, if we detect high-risk patient in the operating room, we could practice early intervention to decrease mortality and morbidity. The purpose of this study was to determine whether the intraoperative lactate or UMA levels can predict adverse outcomes in pediatric cardiac patients with undergoing cardiopulmonary bypass (CPB). We studied 102 patients with congenital heart disease. Arterial blood samples were obtained after inducing anesthesia, 5 min after weaning from CPB and after chest closure. Major adverse events (MAEs) were defined as cardiac compression, re-sternotomy due to hemodynamic instability, extra-corporeal membrane oxygenator support, creatinine levels greater than 2 mg/dL, or death. Patients were divided into MAE group (8 patients, 7.8%) and non-MAE group. Six patients with MAEs died. Importantly, the lactate levels (mmol/L) at weaning from CPB (4.19 vs 2.1; MAE group vs non-MAE group), chest closure (5.76 vs 2.39; MAE group vs non-MAE group) and the intraoperative increases in lactate levels were significantly higher in the MAE group than in the non-MAE group. However, there was no significant difference in the UMA levels or their changes between the groups. The increase in the lactate level from CPB weaning to chest closure was the best predictor of MAEs (AUC: 0.810). In conclusion, the intraoperative plasma lactate levels were more closely associated with MAEs, and they are more useful for predicting the outcome of pediatric cardiac patients than the UMA levels.

Application of the continuous autotransfusion system (CATS) to prevent transfusion-related hyperkalemia following hyperkalemic cardiac arrest in an infant -A case report-.

Transfusion-induced hyperkalemia can lead to cardiac arrest, especially when the patient rapidly receives a large amount of red blood cells (RBCs), previously stored for a long period of time, irradiated or both. We report on a case of application of the Continuous AutoTransfusion System (CATS) to wash RBCs, in order to lower the high potassium (K(+)) level in the packed RBCs unit, during massive transfusion following transfusion-induced hyperkalemic cardiac arrest. After the washing process using CATS, there was no more electrocardiographic abnormality or cardiac arrest due to hyperkalemia. This case emphasizes the potential risk to develop transfusion-related hyperkalemic cardiac arrest, during massive transfusion of irradiated, pre-stored RBCs. CATS can be effectively used to lower the K(+) concentration in the packed RBCs unit, especially when the risk of transfusion-induced hyperkalemia is high.

17ß-Estradiol attenuates the activity of the glutamate transporter type 3 expressed in Xenopus oocytes.

Estrogen, a neuroactive sex hormone in the brain, enhances neuronal excitability and increases seizures. Glutamate transporters help in limiting the excitatory neurotransmission by uptaking glutamate from the synapses. We investigated the effects of 17ß-estradiol on the activity of a glutamate transporter, excitatory amino acid transporter 3 (EAAT3), in Xenopus oocytes. EAAT3 was expressed in Xenopus oocytes by injection of rat EAAT3 mRNA. l-Glutamate (30 µM)-induced membrane currents mediated by EAAT3 were measured using the two-electrode voltage clamp technique. 17ß-Estradiol reduced EAAT3 activity in a concentration- and time-dependent manner. 17ß-Estradiol (10nM for 72h) significantly decreased V(max) but had no effect on K(m) of EAAT3 for glutamate. When 17ß-estradiol treated oocytes were incubated with phorbol-12-myrisate-13-acetate, a protein kinase C (PKC) activator, 17ß-estradiol-induced decrease in EAAT3 activity was abolished. Furthermore, in pretreatment of oocytes with chelerythrine or staurosporine, two PKC inhibitors, EAAT3 activity was significantly decreased. However, there was no statistical difference among the 17ß-estradiol, PKC inhibitor, or 17ß-estradiol plus PKC inhibitor groups. Likewise, wortmannin, a phosphatidylinositol 3-kinase (PI3K) inhibitor, significantly reduced basal EAAT3 activity, but the activity did not differ among the 17ß-estradiol, wortmannin, or 17ß-estradiol plus wortmannin groups. Estradiol receptor inhibitor, fulvestrant, did not change the reduced EAAT3 activity by 17ß-estradiol. Our results suggest that 17ß-estradiol decreases EAAT3 activity. PKC and PI3K seem to be involved in this effect, possibly not via estradiol receptors.

Interactions of midazolam and propofol on α1ß2γ2L and α1ß2γ2S gamma aminobutyric acid type A receptors expressed in human embryonic kidney cells.

BACKGROUND: The gamma aminobutyric acid type A (GABA(A)) receptor is a prime target of many anesthetics, including midazolam and propofol. Although these anesthetics have sedative and hypnotic properties by enhancing GABA(A) receptor activity, their interactions at the GABA(A) receptors have not been explored. We investigated the interaction of midazolam and propofol with α(1)ß(2)γ(2)L and α(1)ß(2)γ(2)S GABA(A) receptors. METHODS: Using the whole-cell patch clamp technique, we tested the effects of midazolam and propofol on GABA-induced currents in human embryonic kidney 293 T cells transfected with α(1)ß(2)γ(2)L and α(1)ß(2)γ(2)S GABA(A) receptors. RESULTS: Midazolam and propofol on their own enhanced the amplitude of GABA(A) receptor responses in a dose-dependent manner, and they had additive effects on α(1)ß(2)γ(2)S GABA(A) receptors, but not on α(1)ß(2)γ(2)L GABA(A) receptors. However, additive interactions of midazolam and propofol on the α(1)ß(2)γ(2)L GABA(A) receptors were observed when protein kinase C was inhibited. CONCLUSIONS: The interaction between midazolam and propofol is affected by receptor subtype, and protein kinase phosphorylation influences their interaction on the α(1)ß(2)γ(2)L receptor.

The effect of cardioplegic solution-induced sodium concentration fluctuation on postoperative seizure in pediatric cardiac patients.

BACKGROUND: Despite potential benefits of histidine-tryptophan-ketoglutarate (HTK) solution as a cardioplegic solution, it can cause hyponatremia, especially in pediatric patients. Fluctuations in the sodium concentration during cardiopulmonary bypass (CPB) can adversely affect the central nervous system. We evaluated the relationship between the cardioplegic solution, the fluctuation of sodium concentration, and the incidence of postoperative seizure in pediatric cardiac patients. METHODS: The medical records of 628 patients were reviewed for the occurrence of a postoperative seizure, type of cardioplegic solution (HTK or del Nido solution), and intraoperative data. A change of sodium concentration exceeding 15 mmol/L (ΔNa>15) during CPB was defined as a significant fluctuation of sodium concentration. RESULTS: Postoperative seizures were detected in 18 patients (2.9%). The ΔNa>15 was detected in 63 of 189 patients (33.3%) who received the HTK solution and in 14 of 439 patients (3.2%) who received the del Nido solution (p<0.001). The incidence of ΔNa>15 was strongly associated with postoperative seizure (odds ratio, 6.3; 95% confidence interval, 2.4 to 16.4, p=0.001). After adjusting for potential confounders, the ΔNa>15 remained significantly associated with postoperative seizure (odds ratio, 3.9; 95% confidence interval, 1.3 to 12.3, p=0.018). CONCLUSIONS: Histidine-tryptophan-ketoglutarate solution during CPB frequently causes fluctuations of sodium concentration, usually combined with hyponatremia, which is associated with postoperative seizure. Special attention to sodium concentration is required, particularly when HTK solution is used in pediatric cardiac patients.