Dexmedetomidine is Associated with an Increased Incidence of Bradycardia in Patients with Trisomy 21 After Surgery for Congenital Heart Disease.

This study aimed to evaluate adverse cardiac events using dexmedetomidine in infants with trisomy 21 and those without (controls) and examined potential risk factors in infants after cardiovascular surgery. We conducted a single-center retrospective cohort study. The medical records of 124 consecutive infants who had undergone cardiovascular surgery between April 1, 2013, and October 31, 2015, were enrolled. Clinical characteristics, usage of dexmedetomidine, and perioperative medications were analyzed. Adverse cardiac events were assessed with the Naranjo score and World Health Organization-The Uppsala Monitoring Centre (WHO-UMC) criteria. In total, 124 consecutive infants (30 patients and 94 controls) met the inclusion criteria. Eight of 30 (26.7 %) patients with trisomy 21 and 12 of 94 (12.8 %) controls experienced adverse cardiac events (i.e., hypotension, transient hypertension, and bradycardia) during dexmedetomidine with median Naranjo score of 6, and causality categories of WHO-UMC criteria were "certain" or "probable." Of those, the incidence of bradycardia occurred at a higher rate in patients with trisomy 21 than in controls (P = 0.011). Multiple logistic regression analysis revealed that the presence of trisomy 21 was an independent risk factor for adverse cardiac events of dexmedetomidine after cardiovascular surgery (odds ratio 4.10, 95 % CI 1.17-11.19, P = 0.006). Dexmedetomidine is associated with an increased incidence of bradycardia in patients with trisomy 21 after surgery for congenital heart disease. Physicians using dexmedetomidine should know a great deal about the characteristics of patients with trisomy 21, and hemodynamic monitoring should be closely observed.

Potential risk factors for dexmedetomidine withdrawal seizures in infants after surgery for congenital heart disease.

PURPOSE: Few studies are available on withdrawal seizures about dexmedetomidine (DEX). Thus, we retrospectively evaluated the incidence of withdrawal seizures after discontinuation of DEX and examined potential risk factors in infants after cardiovascular surgery. METHODS: The medical records of 142 infants who had undergone cardiovascular surgery between April 2010 and November 2013 were examined. Clinical characteristics and usage of DEX were analyzed. DEX withdrawal seizures were evaluated using Withdrawal Assessment Tool - version 1 (WAT-1). All the patients and controls were categorized according to DEX discontinuation strategy, which was either gradual or abrupt. RESULTS: Nine patients (6.3%) developed generalized clonic or generalized tonic-clonic seizures accompanied by preceding fever of >38°C approximately four to eight hours following the discontinuation of DEX, and were clinically diagnosed as DEX withdrawal seizures with a median WAT-1 score of 3. Clinical characteristics and operative data were similar, but median cumulative dose and maximum temperature after discontinuation of DEX were significantly higher in infants with withdrawal seizures than in those without (P=0.007 and P<0.001, respectively). Eight of the 9 patients with withdrawal seizures (88.9%) and 20 of the 133 patients (15.0%) with no withdrawal seizures had discontinued DEX abruptly (P<0.001). Cumulative dose and abrupt discontinuation of DEX were significantly associated with DEX withdrawal seizures in infants after cardiovascular surgery (R=0.619, P=0.004). CONCLUSIONS: Physicians should be aware that infants who received DEX after cardiovascular surgery had potential to cause withdrawal seizures accompanied by preceding pyrexia after discontinuation of DEX. Higher cumulative dose and abrupt discontinuation of DEX appears to increase the risk for these withdrawal seizures.

Circulating platelet-neutrophil aggregates play a significant role in Kawasaki disease.

BACKGROUND: Circulating platelet-neutrophil aggregates play a crucial role in amplifying acute inflammation and could promote adverse effects involving vascular injury. The aim of this study was to evaluate the role of platelet-neutrophil aggregates in Kawasaki disease (KD). METHODS AND RESULTS: Forty patients with KD (30 intravenous immunoglobulin [IVIG] responders and 10 IVIG non-responders), 7 febrile patients with bacterial infections, and 9 normal volunteers were analyzed. Thirty-three patients with KD were treated with IVIG, and 7 were treated with IVIG plus prednisolone. We evaluated the rate of platelet-neutrophil aggregates and measured the platelet factor 4 (PF4) and ß-thromboglobulin (ß-TG) levels. The rate of platelet-neutrophil aggregates was significantly higher in patients with KD than those with bacterial infection and normal volunteers. The rate of platelet-neutrophil aggregates was significantly higher in patients with coronary artery abnormalities (CAA) than in those without CAA, and was correlated with PF4 and ß-TG levels in patients with KD. Comparing time-course analysis, the rate of platelet-neutrophil aggregates was significantly decreased in patients treated with IVIG plus prednisolone than in those treated with IVIG alone. CONCLUSIONS: The findings demonstrate that platelet-neutrophil aggregates are significantly present in higher rates and are closely related to pathological developments of CAA in KD. Additional prednisolone treatment for patients in the acute phase of KD could suppress platelet-neutrophil aggregates, indicating that platelet-neutrophil aggregates would inhibit amplified reciprocal vascular inflammatory activation.

Immunoglobulin G values before treatment are correlated with the responsiveness to initial intravenous immunoglobulin therapy for Kawasaki disease.

BACKGROUND: Low levels of serum immunoglobulin G (IgG) before intravenous immunoglobulin (IVIG) therapy for Kawasaki disease (KD) have been reported as one of the risk factors for coronary artery abnormalities (CAAs). This risk factor needs to be re-evaluated because the dosage of IVIG has changed from 0.2-0.4 g/kg/day for 5 days to a single high dose of 2 g/kg. METHODS: We reviewed the clinical records of KD patients admitted to our hospital from January 2001 to August 2011. Patients who were given a single high dose of IVIG within 7 days of illness, and who had blood collected for serum immunoglobulin values before treatment, were selected. The serum immunoglobulin levels and coronary artery diameters measured by echocardiogram were transformed to z-scores. RESULTS: The subjects were 197 KD patients, including 22 IVIG nonresponders and 16 patients with CAAs. Of these, 150 (76%) had a z-score for IgG (IgGz) of ≤0. There were no differences in IgGz values between patients with CAAs and those without CAAs. However, nonresponders had higher IgGz values than responders (median, 25th percentile and 75th percentile: -0.26, -0.83 and 0.34 vs. -0.79, -1.40 and -0.03; p = 0.020). Logistic regression analysis showed that the IgGz value was an independent risk factor for resistance to IVIG (OR 1.36, 95% CI 1.002-1.849; p = 0.048). CONCLUSIONS: Low IgGz values were not a risk factor for CAAs in this study. However, KD patients with relatively high IgGz values before treatment may have an increased risk of resistance to initial IVIG therapy. © 2014 S. Karger AG, Basel.

Kawasaki disease patients with six principal symptoms have a high risk of being a non-responder.

BACKGROUND: A diagnosis of Kawasaki disease (KD) is established using six principal symptoms. Because the principal symptoms are deeply connected with KD, it is thus important to investigate the usefulness of the principal symptoms for evaluating the disease severity of KD. METHODS: Patients with definite KD or suspicion of KD were retrospectively examined. Blood test data and the incidence of patients who failed to respond to the initial i.v. immunoglobulin treatment (non-responders) were compared between patients with six principal symptoms, including fever of ≤ 4 days, before treatment of KD (six-symptom patients), and those with five or fewer symptoms (five-symptom patients). RESULTS: The study group of 207 patients who were treated with immunoglobulin consisted of 121 six-symptom patients and 86 five-symptom patients. The six-symptom patients were older and had higher neutrophil proportion and total bilirubin, and lower serum sodium at diagnosis than the five-symptom patients. Although the treatments did not differ between the groups, the six-symptom patients had a higher incidence of non-responders than the five-symptom patients (17% vs 5%; P= 0.008). Logistic regression analysis showed that six-symptom status was related to the risk of being a non-responder (odds ratio [OR], 5.3; 95% confidence interval [95%CI]: 1.6-17.4). This association was still significant after adjustment for the effect of age, neutrophil proportion, and total bilirubin and sodium (OR, 4.4; 95%CI: 1.4-17.3). CONCLUSIONS: The number of principal symptoms before treatment is a useful guide to KD disease severity. Six-symptom patients have a higher risk of being a non-responder than five-symptom patients.

Serum procalcitonin value is useful for predicting severity of Kawasaki disease.

We measured serum procalcitonin concentrations in 160 patients suffering from Kawasaki disease. Serum procalcitonin was significantly higher in nonresponders to an initial intravenous immunoglobulin treatment than in responders. A cutoff value of procalcitonin (0.5 ng/mL) for nonresponders showed that the sensitivity was 85% and the accuracy was 64%. Multivariate logistic regression analysis revealed that procalcitonin-positive cases showed the highest risk for nonresponders.

An elevated value on drug-induced lymphocyte stimulation test for immunoglobulin is an immunological abnormality of Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is an acute febrile vasculitis in childhood. Currently, treatment with 2 g/kg of intravenous immunoglobulin (IVIG) is recommended. Previously we had encountered a patient with KD who showed persistent fever and a severe eruption after IVIG treatment. Using a drug-induced lymphocyte stimulation test (DLST), he was positive for an immunoglobulin product. The aim of this study was to clarify the importance of a positive value for the DLST for immunoglobulin products in KD patients. METHODS: Subjects were 30 confirmed KD patients treated with IVIG at the Kagoshima Medical Association Hospital. DLST values were compared between patients with additional events and those without additional events using the stimulation index (SI = value of (3)H-thymidine absorption with antigen/without antigen). Additional events were defined as symptoms observed after IVIG that were considered unexplainable by the symptoms of KD alone. RESULTS: DLST results were evaluated in 13 patients with additional events and 17 patients without additional events. Elevated DLST values were observed not only in patients with additional events but also in those without additional events. Elevated SI values were observed in the initial 14 days after IVIG and the SI values in this period were significantly higher than those after day 14 (initial 14 days, n = 20, 194 +/- 112%; after day 14, n = 10, 117 +/- 66%, p = 0.010). CONCLUSIONS: Elevated SI values of DLST for immunoglobulin products are not related with additional events. Our results show they may represent one of the immunological abnormalities of KD.

A severe form of Kawasaki disease presenting with only fever and cervical lymphadenopathy at admission.

OBJECTIVE: To examine the characteristics of patients with Kawasaki disease (KD) presenting with only fever and cervical lymphadenopathy at admission. STUDY DESIGN: The laboratory and clinical findings of patients with definite KD presenting with only fever and cervical lymphadenopathy at admission (KDiL) were compared with those of all other patients with KD. RESULTS: Sixteen patients with KDiL (8.6%) and 171 patients without KDiL were examined. The patients with KDiL were significantly older (KDiL/non-KDiL: 4.9+/-2.5/2.2+/-1.9 years) and admitted earlier (3.0+/-1.2/3.9+/-1.3 days of illness) than the patients without KDiL. They also showed significantly elevated white blood cell counts and C-reactive protein levels. Patients with KDiL were treated with the same dose of intravenous immunoglobulin as the patients without KDiL but were treated slightly later and had significantly higher frequency of additional intravenous immunoglobulin treatment (38%/10%) and coronary artery abnormalities (25%/5%). After adjustment for age, white blood cell count, and day of illness at admission or first intravenous immunoglobulin administration, the presence of KDiL significantly increased the risk of being a nonresponder to IVIG treatment or development of a coronary artery abnormality. CONCLUSIONS: KDiL indicates a severe form of KD associated with increased risks of additional intravenous immunoglobulin treatment and coronary artery abnormalities. Patients with KDiL may require heightened surveillance and more aggressive treatment.

Platelet vascular endothelial growth factor is a useful predictor for prognosis in Kawasaki syndrome.

Kawasaki syndrome (KS) is an acute febrile vasculitis of childhood. Coronary artery abnormalities (CAA) are a significant problem in KS patients. High dose intravenous immunoglobulin (IVIG) is effective for reducing the occurrence of CAA. Clinical and histopathological findings suggest that vascular endothelial growth factor (VEGF) is involved in CAA. In circulating blood, newly activated platelets are the major source of VEGF, which is released in large amounts in vascular inflammation. The present study analysed 80 KS patients (69 IVIG responders and 11 IVIG non-responders) and evaluated the role of platelet VEGF in KS vasculitis. Serum VEGF and platelet VEGF levels were significantly higher in KS patients than controls (P < 0.001). Platelet VEGF reflected the reactivity of IVIG treatment and was decreased in responders (P < 0.001), but remained increased in non-responders (P = 0.01). Platelet VEGF levels, but not serum VEGF levels, before IVIG were significantly correlated with the maximum CAA z-score (r = 0.524, P = 0.02). Our findings demonstrate that platelet VEGF may reflect the severity of vasculitis related to the pathological development of CAA in KS. Platelet VEGF may be an important feature of KS pathophysiology.

An elevated value of high mobility group box 1 is a potential marker for poor response to high-dose of intravenous immunoglobulin treatment in patients with Kawasaki syndrome.

We examined the serum values of high mobility group box 1 (HMGB1) in 36 patients with Kawasaki syndrome (KS) (29 responders and 7 poor-responders to initial intravenous immunoglobulin treatment). A mean value of HMGB1 of poor-responders was significantly elevated compared with those of responders (P = 0.0042). Among the 6 factors showing significant differences between responders and poor-responders including HMGB1 (admission illness day, white blood cell counts, C-reactive protein, aspartate aminotransferase, lactate dehydrogenase), values of HMGB1 showed the widest area under the receiver operating characteristic curve. In conclusion, an elevated HMGB1 value could be a potential marker for poor-responders.

Early diagnosis of Kawasaki disease in patients with cervical lymphadenopathy.

BACKGROUND: Among typical patients with Kawasaki disease (KD), a few KD patients present with only fever and cervical lymphadenopathy at admission (KDL). These patients have a significant risk for misdiagnosis, delay in treatment for KD, and development of coronary artery abnormalities. Therefore, the development of an easy tool for early diagnosis in these patients is desirable. METHODS AND RESULTS: Patients who presented with only fever and cervical lymphadenopathy at admission were studied. Of these, 14 patients were eventually diagnosed with KD (KDL) and 24 patients were successfully treated using antibiotics (control). KDL patients were significantly older than control patients (P > 0.022). Among the laboratory findings, neutrophil counts (P > 0.003), C-reactive protein (CRP; P < 0.001), and aspartate aminotransferase (AST; P > 0.018) were significantly different between the groups. To discriminate KDL patients from controls, cut-off points of the aforementioned parameters (KDL indices) were determined using the receiver operating characteristic curves in order to maximize sensitivity and accuracy (age, 5.0 years; neutrophil counts, 10,000 /microL; CRP, 7.0 mg/dL; AST, 30 IU/L). One point was assigned if a subject exceeded the cut-off point in a KDL index. If a patient with three or four KDL indices was considered to have KD, the sensitivity was 78% and the specificity 100%. None of the patients with one or zero KDL index developed KD. CONCLUSIONS: KDL indices may be helpful in discriminating KDL from lymphadenitis at admission. It is important to monitor the symptoms of KD in a patient with three or four KDL indices at admission.

Suspected takotsubo cardiomyopathy caused by withdrawal of bupirenorphine in a child.

A 2-year-old Japanese girl had transient left ventricular apical ballooning on echocardiography and ST-segment elevation and T-wave inversion on electrocardiogram after withdrawal of bupirenorphine and midazolam. The findings improved within 2 weeks. There are many case reports of adults with takotsubo cardiomyopathy but none in children. Takotsubo cardiomyopathy is not well known by pediatric cardiologists, so pediatric cases may have been overlooked. Awareness of a phenomenon similar to takotsubo cardiomyopathy, even in young children, may be important.

Interval representative of transmural dispersion of repolarization in children and young adolescents with congenital long QT syndrome.

BACKGROUND: It has been shown experimentally that the interval from the nadir of the initial negative T wave to the end of the T wave is representative of transmural dispersion of repolarization (TDR) when complex T waves are present. In the clinical setting, however, the interval representative of TDR in patients with long QT syndrome (LQTS) is a controversial subject. METHODS AND RESULTS: Five symptomatic patients (3 boys, 2 girls; 3 LQT1, 2 LQT2) were evaluated by a face immersion test before and after treatment to compare the configuration of the T wave. When the notch disappeared after treatment, the single peak of the T wave after treatment coincided with the nadir of the notch before treatment. When the notch remained the same after treatment as before treatment and when the QTc decreased, the corrected interval from the nadir of the notch to the end of the T wave was for the most part shortened. CONCLUSIONS: The present study showed that the interval representative of the TDR in the clinical surface electrocardiogram can be obtained from the nadir of the notch to the end of the T wave in children and adolescents with LQTS, as was shown in the experimental study.

Heart rate variability and ambulatory blood pressure monitoring in young patients with hypertrophic cardiomyopathy.

BACKGROUND: Sudden cardiac death commonly occurs in young patients with hypertrophic cardiomyopathy (HCM); however, their heart rate variability (HRV) and blood pressure (BP) response to daily life activities is not well known. METHODS AND RESULTS: HRV and ambulatory BP monitoring were performed in 20 patients (age range: 7-21 years) and 57 age-matched healthy volunteers (age range: 10-22 years). Time domain variables and spectral data were obtained at hourly intervals throughout the day. To determine the BP response to daily life activities, the ratios of the mean BP and pulse pressure in the morning, afternoon, and night to those during sleeping were calculated. The association between the BP level and HRV was also evaluated. The HCM patients showed significantly increased sympathovagal imbalance and decreased parasympathetic activity in the early morning, around noon, and in the early evening. This abnormality was independent of cardiac symptoms. Symptomatic patients showed a significantly lower systolic BP response in the morning, and a higher incidence of dissociation between sympathetic activity and BP response than asymptomatic patients. CONCLUSION: An abnormal BP response in the presence of impaired HRV appears to be predictive for cardiac events in young patients with HCM.

Infected aneurysm of the ascending aorta in childhood: report of a case.

Infected aneurysms of the thoracic aorta are rare in children, and many are not diagnosed until autopsy. We report the case of a 3-year-old girl in whom an infected aneurysm of the ascending aorta was successfully repaired by Dacron patch angioplasty under cardiopulmonary bypass.