Airway Reactance Predicts Static Lung Hyperinflation in Severe Asthma

BACKGROUND AND OBJECTIVES

Background: Static lung hyperinflation (SLH) measured using body plethysmography in patients with asthma is associated with poor outcomes. The severity of SLH may be associated with small airway dysfunction (SAD), which can be measured using impulse oscillometry (IOS). Objective: This study aims to determine the correlation between SLH and SAD in patients with severe asthma and assess the improvement in SLH and SAD with treatment.

METHODS

We analyzed data from patients who were enrolled in the Taiwan Severe Asthma Registry, which comprises a prospective observational cohort. Plethysmography and IOS were performed regularly. The relationship between spirometry and IOS parameters was determined. Changes in the clinical outcomes in response to treatment were analyzed.

RESULTS

Of 107 patients with severe asthma, 83 (77.6%) had SLH based on an increased residual volume to total lung capacity ratio (RV/ TLC). Most patients were older women with worse pulmonary function and SAD than those without SLH. SAD, defined as increased airway resistance/reactance, was significantly correlated with SLH. Airway reactance at 5 Hz (X5) ≤-0.21 kPa/(L/s) detected SLH with an area under the receiver operating characteristic curve of 0.84 (P<.0001; sensitivity, 85.2%; and specificity, 83.3%). After 12 months, patients who received add-on biologics (vs those who did not) had significantly reduced exacerbations, fractional exhaled nitric oxide level, and blood eosinophil counts, as well as improved forced expiratory volume in the first second, X5, and a trend toward reduced RV/TLC ratio.

CONCLUSIONS

In severe asthma, airway reactance (X5) could be a novel parameter for assessing SLH.

Small left atrial size complicating percutaneous transcatheter device closure of secundum atrial septal defect with conventional approach

Background and Objectives

Transcatheter device closure becomes the first option for treating secundum atrial septal defect (ASD), but the conventional method is sometimes unsuccessful even when the defect size indicates the closure to be feasible. To increase the success rate, modified methods have been introduced and used. This study aimed to find predictors for using the modified methods in the device closure of secundum ASDs.

Subjects and Methods

Between October 2010 and December 2012, 92 patients with ASDs underwent the transcatheter device closure. We analyzed the sizes of the defect, the surrounding rims, and the ratios of the left atrium (LA) dimensions to the device size in the patients who underwent the procedure either using the conventional or modified methods.

Results

Among the 88 successful cases (95.7%), 22 patients (25%) required modified methods (12 using pulmonary vein and 10 using balloon). The modified method group had the larger size of ASDs and smaller posterosuperior rim. The mean ratios of the LA anteroposterior diameter, width, and length to the device size were all significantly smaller in the modified methods group than in the conventional group (1.20 vs. 1.56, 1.32 vs. 1.71, and 1.61 vs. 2.07, respectively). We found that the risk factors for the modified methods were smaller retroaortic rim, larger ASD, and smaller LA dimension/device size.

Conclusion

In addition to larger defects and smaller retroaortic rim, the smaller ratios of the LA dimensions to the device size influenced the need for the application of modified methods in the transcatheter device closure of ASDs.

Segmental Analysis of Right Ventricular Longitudinal Deformation in Children before and after Percutaneous Closure of Atrial Septal Defect

Background

The aim of study is to identify the dependence of right ventricular (RV) free wall longitudinal deformation on ventricular loading through segmental approach in relatively large number of patients with atrial septal defect (ASD).

Methods

Patients with ASD (n = 114) and age matched healthy children (n = 60) were echocardiographically examined the day before percutaneous device closure and within 24 hours afterwards. RV free wall deformation parameters, strain (є) and strain rate (SR), were analyzed in the apical (є_A, SR_A) and basal (є_B, SR_B) segments. Measured deformation parameters were adjusted for RV size (є_AL, SR_AL, є_BL, SR_BL) by multiplying by body surface area indexed RV longitudinal dimension. Regression analyses determined the relationships of these deformation parameters with RV loading parameters that were measured by catheterization.

Results

є_BL and SR_BL were not different between pre-closure patients and controls (p = 0.245, p = 0.866), and were decreased post-closure (p = 0.001, p = 0.018). Post-closure є_BL was lower than in controls (p = 0.001). Pre-closure є_AL and SR_AL were higher than in controls (p = 0.001, p < 0.001), but decreased after closure (all p < 0.001). The pulmonary to systemic flow ratio was related to procedural differences of є_BL (p = 0.017) and of SR_BL (p = 0.019). RV end diastolic pressure was negatively related to post-closure є_BL (p = 0.020) and post-closure SR_BL (p = 0.012), and the procedural SR_BL difference (p = 0.027).

Conclusion

The longitudinal deformation of the RV basal segment is dependent and its remodeling is also dependent on volume loading in children with ASD.

Outcome of neonates with Ebstein's anomaly in the current era

Ebstein's anomaly is frequently detected before birth, with prenatal detection accounting for the majority of cases in the current population. This study aimed to identify the outcome variables among these infants. The medical records of 59 patients with neonatal Ebstein's anomaly managed at the Asan Medical Center between January, 2001 and June, 2012 were investigated retrospectively. In 46 cases, the diagnosis was made prenatally. Surgical/interventional procedures were performed for 27 of the analyzed patients. Biventricular repair was successful for 12 patients but not for 9 patients with pulmonary atresia. The median follow-up period was 1.96 years (range 0.0-10.4 years). The overall mortality rate was 23.7 % (14/59). Of the 14 deaths, 5 occurred within several hours after birth. The 1- and 5-year survival rates were 78.6 and 76.3 %, respectively. Univariate analysis identified several variables related to the time to death: fetal distress (p = 0.002), prematurity (p = 0.036), low birth weight (p = 0.003), diameter of the atrial septal defect (p = 0.022), and pulmonary stenosis/atresia (p = 0.001). Neither the Carpentier classification (p = 0.175) nor the Celermajer index (p = 0.958) was a significant variable. According to the multivariate analysis, fetal distress (p = 0.004) and pulmonary atresia/stenosis (p < 0.001) were significant determinants of outcome. In conclusion, fetal distress and pulmonary atresia/stenosis are significant predictors of mortality in the current population of patients with neonatal Ebstein's anomaly. A close cooperation of associated clinicians is required for an improvement in outcome. To establish a better surgical strategy for patients with Ebstein's anomaly and pulmonary atresia, studies of larger populations are required.

Diagnosis of incomplete kawasaki disease in infants based on an inflammation at the bacille calmette-guérin inoculation site

Background and Objectives

This study was intended to test how the inflammation at the Bacille Calmette-Guérin (BCG) inoculation site (BCGitis) can be a useful a diagnostic feature of Kawasaki disease (KD).

Subjects and Methods

All subjects were infants at the time of admission, and had received BCG vaccination during their neonatal period. There were 54 patients with complete KD (group 1) and 29 patients with incomplete KD (group 2). All 83 patients had BCGitis during the acute phase of illness. Data regarding the coronary artery diameters in 31 age-matched controls were used for comparison.

Results

The 2 patient groups did not differ in clinical and laboratory variables. During the acute phase, the median z scores of the left anterior descending coronary artery (LAD) diameter were 0.20, 0.42, and -0.48 in groups 1, 2, and control respectively, and that of right coronary artery (RCA) diameters were -0.15, -0.16, and -1.17 respectively. The z scores in both patient groups were greater than those in controls (p=0.0014 in LAD and p<0.0001 in RCA between group 1 and controls; p=0.0023 in LAD and p<0.0001 in RCA between group 2 and controls). A similar pattern was observed during the subacute and convalescent phases.

Conclusion

BCGitis is a useful feature in the diagnosis of incomplete KD in infants who received BCG vaccine during neonatal period.

Detection rate and clinical impact of respiratory viruses in children with Kawasaki disease

Purpose

The purpose of this prospective case-control study was to survey the detection rate of respiratory viruses in children with Kawasaki disease (KD) by using multiplex reverse transcriptase-polymerase chain reaction (RT-PCR), and to investigate the clinical implications of the prevalence of respiratory viruses during the acute phase of KD.

Methods

RT-PCR assays were carried out to screen for the presence of respiratory syncytial virus A and B, adenovirus, rhinovirus, parainfluenza viruses 1 to 4, influenza virus A and B, metapneumovirus, bocavirus, coronavirus OC43/229E and NL63, and enterovirus in nasopharyngeal secretions of 55 KD patients and 78 control subjects.

Results

Virus detection rates in KD patients and control subjects were 32.7% and 30.8%, respectively (P=0.811). However, there was no significant association between the presence of any of the 15 viruses and the incidence of KD. Comparisons between the 18 patients with positive RT-PCR results and the other 37 KD patients revealed no significant differences in terms of clinical findings (including the prevalence of incomplete presentation of the disease) and coronary artery diameter.

Conclusion

A positive RT-PCR for currently epidemic respiratory viruses should not be used as an evidence against the diagnosis of KD. These viruses were not associated with the incomplete presentation of KD and coronary artery dilatation.

Effectiveness and safety of percutaneous transcatheter implantation of pulmonary arterial stent in congenital heart disease

Background and Objectives

Pulmonary arterial stenosis is a relatively common complication after corrective operation of congenital heart disease. Unilateral stenosis of pulmonary arteries could result in decrease perfusion of affected lung, pulmonary regurgitation, or elevation of right ventricular pressure. Eventually there are increasing risks of right ventricular failure, arrhythmia, or sudden death. However we have limited data of pulmonary arterial stent in paediatric population as the treatment of branch pulmonary stenosis. This study aimed at validating the effectiveness and investigating complications of pulmonary arterial stent implantation in a single institution during mid-term follow up period.

Subjects and Methods

A total of 42 patients (50 stents) were implanted for treating branch pulmonary arterial stenosis. We used cardiac catheterization for comparing diameter after stent implantation directly and lung perfusion scan indirectly. We also investigated any adverse effect relating the procedure.

Results

Percent stenosis of stenotic lesions were decreased from 54.1±10.7% to 22.8±12.5% (p<0.001) and degree of decrement in affected lung perfusion was declined from 22.7±8.0% to 10.3±9.0% (p<0.001) immediately and lasts during mid-term follow up period. Complication rate relating the procedure was 12% (6 out of 12) and there was no mortality case.

Conclusion

This series showed immediate and short term effectiveness of pulmonary arterial stent in congenital heart defects. We concluded that percutaneous transcatheter implantation of pulmonary arterial stent was safe and effective during short and mid-term follow up period.

Right ventricular outflow tract stenting in a low birth weight infant born with tetralogy of fallot and prostaglandin e1 dependency

Surgical skill and strategy for the correction of tetralogy of Fallot (TOF) have improved and resulted in satisfactory outcomes. However, prematurity and low birth weight continue to remain risk factors for poor outcomes. We present a case of a 2,150 g neonate born with TOF, in whom palliation was achieved with right ventricular outflow tract (RVOT) stenting. Seventy-seven days after the procedure, stenosis of RVOT below the stent was identified. At that time his body weight was 4.9 kg and total corrective surgery was deemed feasible. Eight months following surgical repair, the patient remained well without medical intervention. RVOT stenting may be a viable interim procedure while waiting for a low birth weight neonate born with TOF and prostaglandin E1 dependency to reach optimal weight to undergo corrective surgery.

Perivascular brightness of coronary arteries in Kawasaki disease

OBJECTIVE

Because perivascular echo brightness (PEB) of coronary arteries has been proposed as a criterion for diagnosis of incomplete Kawasaki disease, we assessed the clinical importance of PEB during the acute phase of disease.

STUDY DESIGN

We enrolled 58 patients with Kawasaki disease who underwent two-dimensional strain analysis of images of pericoronary tissue taken during the acute and the convalescent phases. Echogenicity of pericoronary tissue and of the blood pool was determined by speckle tracking in the respective areas of imaging as the averages of integrated backscatter over a single cardiac cycle. PEB was defined as echogenicity of pericoronary tissue minus blood pool.

RESULTS

PEB did not differ in the acute phase in patients and control subjects (P = .10) and between phases of disease (P = .25). In comparison between patient groups, the presence of pericardial effusion was higher in patients with higher PEB during the acute phase (n = 30) than in the remaining patients (33% versus 4%, P < .01).

CONCLUSIONS

PEB did not differ between patients and control subjects and is only associated with the presence of pericardial effusion during the acute phase of Kawasaki disease. Our data do not confirm the reliability of PEB as a useful diagnostic sign of incomplete Kawasaki disease.

Log-transformed plasma level of brain natriuretic peptide during the acute phase of Kawasaki disease is quantitatively associated with myocardial dysfunction

Purpose

Brain natriuretic peptide (BNP) has been considered a biochemical marker for myocarditis in Kawasaki disease. We performed this study to determine its quantitative significance.

Methods

We attempted to correlate log-transformed BNP concentrations (log-BNP) and clinical, laboratory, and echocardiographic variables in 81 children with Kawasaki disease. Stepwise multiple linear regression analysis was used to determine the variables independently associated with log-BNP concentration.

Results

Serum C-reactive protein level (P<0.0001), serum alanine aminotransferase concentration (P=0.0032), white blood cell count (P=0.0030), and left ventricular mass index (P=0.0024) were positively related with log-BNP, and hemoglobin level (P<0.0001), serum albumin level (P<0.0001), Na⁺ concentrations (P<0.0001), left ventricular fractional shortening (P=0.0080), and peak early diastolic tissue velocity of the left ventricular basal lateral segment (P=0.0045) were negatively related to the log-BNP concentration. Multiple regression analysis showed that serum albumin concentration (R₂=0.31, P=0.0098) and left ventricular mass index (R₂=0.09, P=0.0004) were significantly associated with the log-BNP concentration.

Conclusion

Elevated BNP levels during the acute phase of Kawasaki disease may be attributable to cardiac dysfunction associated with the increase in left ventricular mass, and log-BNP concentration may be a quantitative biochemical marker of myocarditis in Kawasaki disease.

Utility of the rapid B-type natriuretic peptide assay for detection of cardiovascular problems in newborn infants with respiratory difficulties

BACKGROUND

Because the major problems of respiratory difficulties in newborn infants are due to cardiopulmonary problems, improving the early detection and referral of newborn infants with cardiovascular problems has been considered one of the primary goals of care in the neonatal intensive care unit.

OBJECTIVE

To evaluate whether rapid plasma B-type natriuretic peptide (BNP) assay could be used as a screening test to detect the cardiovascular problems in newborn infants with respiratory difficulties.

METHODS

We studied 73 newborn infants >or=34 weeks gestational age presenting with respiratory difficulties during the first few days after birth; they were divided into a cardiovascular problem group (CP group, n = 32) and a noncardiac problem group (NP group, n = 41) according to the presence of cardiovascular problems by clinical and/or echocardiographic studies in newborn infants with respiratory difficulties.

RESULTS

On admission, the median (25-75%) BNP concentration of the CP group was significantly higher than that of the NP group [1,038 (578-1,435) vs. 240 (118-388) pg/ml, p < 0.001]. The best cutoff BNP values for differentiating the CP group were 346.0, 421.0, 570.5 and 191.5 pg/ml within 18 h, at 18-36 h, at 36-60 h and after 60 h of life, respectively. Although the plasma BNP measurement was not a single confirmative test, it was found to have a high sensitivity and a high negative predictive value for rapidly ruling out serious cardiovascular problems in neonatal respiratory difficulties.

CONCLUSION

A rapid plasma BNP assay may be useful for detection of cardiovascular problems in newborn infants with respiratory difficulties during the first few days after birth.

The prevalence of atopy and asthma among university freshmen in Seoul, Korea: association with obesity

The aims of this study were to investigate the prevalence of atopy, asthma, and obesity in university freshmen and to determine whether leptin is associated with bronchodilator reversibility in obesity. A total of 537 university freshmen completed International Study of Asthma and Allergies in Children (ISAAC) questionnaire and underwent skin prick testing and bronchodilator reversibility test. The prevalences of asthma, wheeze, and atopy were 10 (1.9%), 84 (15.6%), and 198 (36.9%), respectively. The mean (+/- SD) bronchodilator response (5.1 +/- 4.4%) was higher in the overweight/obese men than in the normal male subjects (3.7 +/- 3.2%, p < 0.05). The mean leptin level in the overweight/obese men was 5.55 +/- 3.48 ng/mL, which was significantly higher than that (2.78 +/- 1.65 ng/mL) of the normal male subjects. The prevalence of asthma among university freshmen is seriously under-diagnosed and leptin may play a role in bronchodilator reversibility in overweight/obese young men.

Methodological investigation of measuring nasopharyngeal temperature as noninvasive brain temperature analogue in the neonate

OBJECTIVES

(a) To investigate in a newborn animal model whether nasopharyngeal temperature is more closely related to epidural brain temperature than rectal temperature and (b) to investigate in human neonates whether measurement of nasopharyngeal temperature is dependent on the measurement site and other conditions.

DESIGN AND SETTING

(a) Animal experiment in newborn piglets, at an institute for surgical research. (b) Prospective study in human neonates, at a neonatal intensive care unit of a tertiary care university hospital. ANIMALS AND PATIENTS: (a) Nineteen tracheostomized ventilated newborn piglets. (b) Twenty-two spontaneously breathing human newborns nursed either in an incubator or a cot.

MEASUREMENTS AND RESULTS

(a) In the piglets nasopharyngeal temperature (Tnasoph) measured at the nose-ear distance, defined as distance from the inner brim of the nostril to the tragus and inner rim of the meatus accusticus, most closely reflected epidural temperature (Tepidur) at the epidural surface (r2 = 0.89), followed by skin temperature at the temple, rectal temperature (Trectum) at 2 cm depth, and esophageal temperature (Tesoph) in the middle esophagus. Tnasoph did not significantly differ before and after tracheostomy. (b) In the newborns Tnasoph was significantly lower than Trectum. Measurements of Tnasoph at nose-ear distance within a feeding tube had a high precision and were unaffected by breathing or head turning. A nasopharyngeal probe was imaged by magnetic resonance imaging in four newborns of various body weight; its tip when inserted to a depth equal to nose-ear distance was anatomically closest to the brain base but separated from it by tissue layer 2.2 cm thick.

CONCLUSIONS

Tnasoph measured at a position anatomically closest to the brain reflects epidural brain temperature more closely than Trectum. When measured at nose-ear distance it is unaffected by breathing or head turning. Measuring Tnasoph within a feeding tube and standardizing the measuring position is crucial for its use as brain temperature analogue.

Early biochemical indicators of hypoxic-ischemic encephalopathy after birth asphyxia

Hypoxic-ischemic encephalopathy (HIE) after perinatal asphyxia is a condition in which serum concentrations of brain-specific biochemical markers may be elevated. Neuroprotective interventions in asphyxiated newborns require early indicators of brain damage to initiate therapy. We examined brain-specific creatine kinase (CK-BB), protein S-100, and neuron-specific enolase in cord blood and 2, 6, 12, and 24 h after birth in 29 asphyxiated and 20 control infants. At 2 h after birth, median (quartiles) serum CK-BB concentration was 10.0 U/L (6.0-13.0 U/L) in control infants, 16.0 U/L (13.0-23.5 U/L) in infants with no or mild HIE, and 46.5 U/L (21.4-83.0 U/L) in infants with moderate or severe HIE. Serum protein S-100 was 1.6 microg/L (1.4-2.5 microg/L) in control infants, 2.9 microg/L (1.8-4.7 microg/L) in asphyxiated infants with no or mild HIE, and 17.0 microg/L (3.2-34.1 microg/L) in infants with moderate or severe HIE 2 h after birth. No significant difference was detectable in serum neuron-specific enolase between infants with no or mild and moderate or severe HIE 2 and 6 h after birth. A combination of serum protein S-100 (cutoff value, 8.5 microg/L) and CK-BB (cutoff value, 18.8 U/L) 2 h after birth had the highest predictive value (83%) and specificity (95%) of predicting moderate and severe HIE. Cord blood pH (cutoff value, <6.9) and cord blood base deficit (cutoff value, >17 mM) increase the predictive values of protein S-100 and CK-BB. We conclude that elevated serum concentrations of protein S-100 and CK-BB reliably indicate moderate and severe HIE as early as 2 h after birth.

Propofol versus midazolam for intensive care unit sedation after coronary artery bypass grafting

OBJECTIVE

To compare the safety and effectiveness of propofol (2,6-diisopropylphenol) to midazolam for sedation of mechanically ventilated patients after coronary artery bypass grafting.

DESIGN

Open, randomized, prospective trial.

SETTING

Cardiothoracic intensive care unit (ICU), Cleveland Clinic Foundation.

PATIENTS

Eighty-four patients with normal or moderately impaired left ventricular function who underwent elective coronary artery bypass graft surgery under high-dose opioid anesthesia.

INTERVENTIONS

Patients were randomly selected to receive either propofol (mean loading dose 0.24 mg/kg; mean maintenance dose 0.76 mg/kg/hr) or midazolam (mean loading dose 0.012 mg/kg; mean maintenance dose 0.018 mg/kg/hr). Infusion rates were titrated to keep patients comfortable, drowsy, and responsive to verbal stimulation. Study duration, 8 to 12 hrs; infusions were started in the ICU when patients were awake and hemodynamically stable.

MEASUREMENTS AND MAIN RESULTS

During therapy, both groups had lower mean arterial pressures and heart rates compared with baseline measurements; however, the propofol group had significantly lower heart rates than the midazolam group during the first 2 hrs of infusion. The propofol group also had significantly lower blood pressure measurements 5 and 10 mins after the initial dose, although there was no difference during infusion. Baseline cardiac output was measured before starting the infusion, and measurements were repeated during continuous infusion at 4, 8, and 12 hrs. Cardiac output values were similar. Propofol maintenance infusions ranged from 3 to 30 micrograms/kg/min and midazolam infusions ranged from 0.1 to 0.7 micrograms/kg/min. At these infusion rates. both groups had adequate sedation, based on nurse and patient evaluations; however, the propofol group used significantly lower total doses of sodium nitroprusside and supplemental opioids.

CONCLUSIONS

Both propofol and midazolam provided safe and effective sedation of coronary artery bypass graft patients recovering from high-dose opioid anesthesia. The reduced need for both antihypertensive medication and opioids seen in the propofol group may be advantageous. However, the hypotension seen after the initial bolus dose of propofol may be a concern. No difference between the two drugs could be demonstrated in time to extubation or ICU discharge, although it is probable that time to extubation was governed more by residual operative opioids than the study agents.

[Monitoring fetal delivery by oxycardiotocography]

Oxycardiotocography is a combination of cardiotocography and continuous registration of the foetal arterial oxygen saturation (SaO2). In a few cases, the value of this additional information of foetal SaO2 is demonstrated. During uncomplicated deliveries with normal foetal heart rate patterns, the foetal SaO2 usually ranges between 50% and 70%. Uterine hyperactivity with impaired perfusion of the placenta shows besides a changed heart rate patterns, a significant decrease of the foetal oxygen saturation. Conversely, by supplying oxygen to the mother with a mask, the foetal oxygen saturation can be increased by approx. 10%. In case of a breech presentation and application of the sensor to the buttocks, the measured O2-saturation is approx. 10% to 15% below the values usually obtained from the scalp because the tissue there is supplied with mixed blood after the ductus.