Klaus Pfurtscheller

A retrospective analysis of securing autologous split-thickness skin grafts with negative pressure wound therapy in paediatric burn patients

BACKGROUND AND AIM Deep dermal and full-thickness burn wounds are excised and grafted with split-thickness skin grafts. Especially in less compliant patients such as young children, conventional fixing methods can often be ineffective due to high mobility rates in this age group. The aim of this retrospective single-centre study was to give an overview of our experience in the fixation of autologous split-thickness skin grafts (ASTSGs) on burn wounds by negative pressure wound therapy (NPWT) in paediatric patients. METHODS A retrospective analysis describing 53 paediatric patients with burns or burn-related injuries who were treated as 60 individual cases were conducted. All patients received ASTSGs secured by NPWT. RESULTS Of the individual cases, 60 cases with a mean age of 8±6 years (the youngest was 3 months, the eldest was 24 years old) were treated in a single procedure with ASTSG and NPWT. Total burn surface area (TBSA) was, median (med) 4.5% (3.0-12.0%). The TBSA of deep dermal thickness to full-thickness (IIb-III°) burns was med 4.0% (2.0-6.0%). The TBSA treated with ASTSG and NPWT was med 3.5% (2.0-6.0%). Take rate was, med 96% (90-99%) with a total range of 70-100%. The only significant correlation that could be found was between the grafted TBSA and the take rate. The smaller the grafted TBSA the better the take rate resulted, as expected. In three cases, major complications were noted. CONCLUSION To sum up our experience, the NPWT system has developed itself to be a constant, well-implemented and useful tool in securing ASTSGs to the wound bed. The main advantage of the technique is a much higher mobility of the patient compared to conventional fixation methods. The high compliance rate of an often challenging group of patients such as children recompenses possible higher costs compared to conventional fixation methods.

Effects of a fast cable car ascent to an altitude of 2700 meters on EEG and ECG.

In the Eastern Alps, the Dachstein massif with a height of almost 3000 m is an ideal location for investigating the effects of changes in altitude on the human body. Within a few minutes, a cable car facilitates an ascent from 1702 to 2700 m above sea level, where the partial pressure of oxygen is about 550 mmHg (as compared to 760 mmHg at sea level). In this study, 10 healthy subjects performed a reaction time task at 990 m and 2700 m in altitude. The subjects were instructed to perform a right hand index finger movement as fast as possible after a green light flashed (repeated 50 times). The corresponding electrocardiogram (ECG) and the electroencephalogram (EEG) were recorded. From the ECG heart rate and heart rate variability measures in the time and frequency domain were calculated. An event-related desynchronization/synchronization (ERD/ERS) analysis was performed with the EEG data. Finally, the EEG activity and the ECG parameters were correlated. The study showed that with the fast ascent to 2700 m the heart rate increased and the heart rate variability measures decreased. The correlation analysis indicated a close relationship between the EEG activity and the heart rate and heart rate variability. Furthermore it was shown for the first time that the beta ERS in the 14-18 Hz frequency range (post-movement beta ERS) was significantly reduced at high altitude. Very interesting also is the loss of correlation between EEG activity and cardiovascular measures during finger movement at high altitude. The suppressed post-movement beta ERS at the altitude of 2700 m may be interpreted as results of an increased cortical excitability level when compared with the reference altitude at 990 m above sea level.

Chromosomal integration of the HHV-6 genome as a possible cause of HHV-6 detection in cardiac tissues

With interest we read the article published by Comar et al. The authors analysed 35 explanted hearts from children with idiopathic dilated cardiomyopathy (DCM, n=16) or congenital heart disease (CHD, n=11) for the presence of human herpes virus 6 (HHV-6) DNA. They found the HHV-6 B genome in 43.7% and 21% of patients with DCM and CHD, respectively. DNA load ranged from 1.56×102 to 8.6×102 copies/μg DNA (mean 3.06×102 copies/μg). The authors conclude that there might be associations between the myocardial disease and a latent HHV-6 infection.1 However, if HHV-6 DNA is detected in tissue specimens, chromosomal integration of the HHV-6 genome (chromosomally-integrated HHV-6 (CIHHV-6)) should be considered, and further analyses should be undertaken.2,3 We report a case where detection of HHV-6 DNA initially (mis-)led to the diagnosis of HHV-6 associated myocarditis. A 4-year-old girl was admitted with fever and reduced general condition. Echocardiography revealed an enlarged left atrium and left ventricle, severely reduced contractility and moderate mitral valve regurgitation consistent with DCM. Haemodynamics deteriorated with recurrent arrhythmias, hypotension …

Correlation between EEG burst-to-burst intervals and HR acceleration in preterm infants

One objective of this paper is to confirm the coupling between heart rate (HR) changes and electroencephalographic (EEG) bursts (as reported for the first time in Pfurtscheller et al. [K. Pfurtscheller, G.R. Müller-Putz, B. Urlesberger, W. Müller, G. Pfurtscheller, Relationship between slow-wave EEG bursts and heart rate changes in preterm infants, Neurosci. Lett. 385 (2) (2005) 126-130]) in a larger group of preterm infants. Other objectives are to report on semi-automatic detection of burst-to-burst intervals (BBI, time period between the onsets of 2 consecutive EEG bursts) and on correlations between BBI and HR changes. A group of 34 preterm infants with a conceptional age (CA) of 35.9+/-0.6 weeks (mean+/-S.D.) was studied. Periods with a length of about 10 min with low HR variability and discontinuous EEG were selected from long-term EEG and ECG registrations and analyzed. From the automated detection of EEG bursts, an estimate for the mean burst-to-burst interval was obtained. EEG trials with a duration of 16s and a single EEG burst in the middle, were selected and averaged together with the corresponding instantaneous HR trials. It was found that preterm infants without evidence of neurological deficit and with normal development revealed a mean BBI of 13.4+/-2.6s (mean+/-S.D.) and a HR increase of 1.7+/-0.9 bpm (mean+/-S.D.) during the occurrence of EEG bursts. This HR increase is comparable with the earlier reported increase of 1.9+/-0.8 bpm. A significant negative correlation of r=0.453 (p<0.01) was found between BBI and HR increase and a positive correlation between CA and HRV (r=0.438, p<0.01) and between CA and HRI (r=0.452, p<0.01).

Transdermal uptake and organ distribution of silver from two different wound dressings in rats after a burn trauma

Silver‐containing wound dressings are an integral part of wound therapy in adult and pediatric burn patients. The antimicrobial effect of silver is well known and has been described in numerous studies. Side effects are rarely reported from silver‐containing wound care products, even though systemic absorption of silver has been shown by elevated levels of silver in the blood of patients after silver exposure during wound therapy. This animal study investigated the silver levels of blood and in which organs and tissues silver is detectable after long‐term application of silver‐containing wound dressings after a burn trauma. In male rats, a major full‐thickness scald was created on their backs according to a standardized burn model. Two different silver‐containing wound dressings (nanocrystalline silver [NCS] and silver sulphate foam [SSF]) were applied initially and changed every 7 days. Weekly blood drawings revealed an increase of blood silver in week three with significant higher values in the SSF compared with NCS group (Ag μg/kg 135.8 vs. 61.7; means; p ≤ 0.05). Thereafter, the NCS group showed significantly higher blood silver levels than the SSF group at week five (Ag μg/kg 192.3 vs. 81.3; means; p ≤ 0.01) and six (Ag μg/kg 168.2 vs. 32.9; means; p ≤ 0.01). After 6 weeks, the animals were sacrificed, and the organs and tissues were analyzed for their silver content by inductively coupled plasma mass‐spectrometry. Silver was detectable in all analyzed organs and tissue samples, with higher silver values in parenchymatous organs in the NCS than SSF group (Ag μg/kg; spleen: 3,469 vs. 260; kidney: 3,186 vs. 289; liver: 2,022 vs. 313; means; p ≤ 0.05). Silver was also detectable in brain, testis, lung, heart, and muscle tissue.

Differentiating Inherited Human Herpesvirus Type 6 Genome from Primary Human Herpesvirus Type 6 Infection by Means of Dried Blood Spot from the Newborn Screening Card

To differentiate active human herpesvirus type 6 (HHV-6) infection from inherited HHV-6 (iHHV-6), we analyzed dried blood spots from archived newborn screening cards in 3 patients with high HHV-6 DNA copy numbers. Two patients were positive for HHV-6 DNA as neonates suggesting iHHV-6. In 1 patient, the absence of HHV-6 DNA excluded iHHV-6.

Innovative scald burn model and long-term dressing protector for studies in rats.

R are frequently used for experimental studies in burns. Scalding is the easiest mechanism for provoking a dermal burn; the ability to vary water temperature, time of exposure, and the burned area make this method effective for reproducing almost any kind of thermal wound. Last but not least, rats are readily available, inexpensive, and easy to manage. In general, a scald injury in rats is inflicted on anesthetized animals by immersion of the area to be burned into a water bath. The area of exposure is determined by the aperture in the template, which can be an elaborately designed apparatus, a metal wire cage, or a simple metal plate with a rectangular aperture through which the body part is immersed in a water bath for a specified amount of time. To establish a standard long-term method for protecting the burn wound dressings from being eaten by the rats and thereby tainting the scientific results, we searched the relevant literature and found that there was nothing available for that purpose. After several tests, the armor described later used together with our scald template was found to be satisfactory for our experiment series. With the use of the armor, the silver detected in the blood should originate only from the wound, with no additional absorption from the gut. In this article, an innovative scald protocol and armor are being presented.With this template firmly pressed on the shaved back, only the area to be burned is in contact with the boiling water. The burn wound is uniform in size and depth and can certainly be reproduced. The template is easy and fast to fabricate at a low cost and at any size. The armor ensures that the dressings stay in place for a minimum of four or even more weeks and prevents the rats from eating the silver-coated wound material.

Semiautomatisches Verfahren für die Untersuchung des synchronen Verhaltens von EEG- und Herzraten-Mustern bei Frühgeborenen / Semi-automatic procedure for the investigation of synchronized EEG- and heart rate patterns in preterm neonates

Abstract Recordings of the electroencephalogram (EEG) and of the heart rate variability (HRV) of preterm neonates can give important information on the actual state of the nervous system. Both signals, EEG and HRV, are affected by parameters such as gestational age, stage of maturation and behavioral state. This work describes a method for automatic detection of slow wave EEG-bursts and a tool to average changes in the EEG and the corresponding heart rate. The detection is based on the hjorth activity (HA), calculated from the EEG. HA spikes (HAS) are identified by the determination of the beginning and end of existing spikes. HAS maxima and the time between two consecutive HAS are the basis for the triggering of the bursts. EEG power and time synchronized HR changes are averaged with a time window length of 20 s. Resultant, HR increase and duration are determined. These parameters, obtained by the automatic detection, proved to be comparable to the results of an expert. Zusammenfassung Die kontinuierliche und simultane Aufzeichnung des Elektroenzephalogramms (EEG) und der Herzratenvariabilität (HRV) kann bei Risikofrühgeborenen wichtige Informationen über den Zustand des Nervensystems geben. Diese beiden Parameter werden unter anderem vom Gestationsalter, Reifegrad und Verhaltenszustand beeinflusst. In den vom Experten bestimmten Schlafphasen zeigen Frühgeborene ein diskontinuierliches „slow wave“-EEG-Muster. Das Ziel dieser Arbeit war, „bursts“ von „slow waves“ im EEG automatisch zu detektieren und eine Mittelung der EEG-Leistungsänderungen mit der dazugehörigen HR-Änderung bei den gefundenen „bursts” durchzuführen. Die Berechnungen für die Detektion basieren auf der synchron zum EEG berechneten Hjorth-Aktivität (HA). Durch die Bestimmung von Beginn und Ende der vorhandenen „spikes” werden die HA-„spikes“ (HAS) ermittelt. Die HAS-Maxima und die Zeiten zwischen zwei aufeinander folgenden HAS stellen die Grundlage für die Triggerung der „bursts“ dar. Die Mittelung der EEG-Leistung und der zeitlich synchronen HR-Änderung erfolgt mit einer Standardfensterbreite von 20 s mit einer automatischen Berechnung des HR-Anstieges sowie dessen Dauer. Es konnte gezeigt werden, dass die Wertebereiche dieser zwei Parameter, bei den Auswertungen durch den Experten mit den Ergebnissen der automatischen Detektion vergleichbar sind.

Malignant stroke in a female adolescent (Case Presentation)

The Discussion and Diagnosis can be found on page 1070. CASE PRESENTATION An 18-year-old girl is admitted to the hospital because of sudden dizziness and collapse at work. On admission, she has a severe, unilateral, right-sided headache, nausea, and sensory loss and weakness of the left upper and lower extremities as well as left-sided central facial palsy. For a couple of weeks prior to admission, the patient had suffered from frequent headaches. She is a non-smoker and there is no family history on migraine, stroke, myocardial infarction or coagulation disorder. Two months ago she had started oral contraceptives (low-dose oestrogen). Through physical examination she is alert and oriented in time, place and person with adequate responses (Glasgow Coma Scale of 15). On neurologic exam she has flaccid palsy and complete loss of sensation of the left side of the body, central left-sided facial palsy, positive plantar response on the left and pupils are equal and round. Vital signs are stable.

Malignant stroke in a female adolescent (Discussion and Diagnosis)

The Case Presentation can be found on page 929. DISCUSSION Stroke is a rare disorder in childhood, but ranges among the top ten causes of death in children (1). Over the last 10 years the incidence seems to have increased from two to six cases per 100000 children per year (2). The reason for this increase might partly be explained by the enhanced detection rate of minor stroke events or transitory ischaemic attacks due to improved clinical awareness as well as new neuroimaging and laboratory techniques. Another explanation for the increase may be the improved survival of children with previously lethal diseases predisposing to stroke e.g. cardiac malformations. In 40%, the cause of stroke in infancy and childhood remains unclear and half of the cases are found to have multiple risk factors (3). Stroke in this age group is often associated with non-atherosclerotic vasculopathy, congenital or acquired heart disease and central nervous system infections. Hereditary prothrombotic risk factors are suspected to contribute to the risk of ischaemic stroke, but in most cases an additive acquired factor seems to be necessary to trigger a stroke. In our patient the screening for prothrombotic markers reveals a homozygote MTHFR 677T mutation and elevated fasting plasma homocysteine (15.3 μmol/L, normal range: 4.6–12.4 μmol/L). No other prothrombotic risk factors can be identified: global coagulation tests, factor VIII, protein C activity, protein C antigen, protein S antigen free/bound, antithrombin, activated protein C resistance, anti-cardiolipin antibodies, cholesterol and lipoprotein(a) are all within normal limits. Factor-V Leiden mutation and prothrombin 20210A mutation are negative. Both parents are heterozygous for the MTHFR 677CT mutation. The clinical significance of the methylene tetrahydrofolate reductase (MTHFR) 677CT mutation is not completely clear. The literature is controversial about the relation between this mutation and stroke in childhood (4,5). Preliminary data suggest that stroke recurrence is associated with the presence of hereditary thrombophilia (6). MTHFR is an important enzyme in folate metabolism. It catalyses the reaction from 5,10-methylene tetrahydrofolate to 5-methylene tetrahydrofolate, which is needed for the degradation of homocysteine. Homocysteine is a wellknown risk factor for vasculopathy and a reason for early onset atherosclerosis (more accumulation of lipids and proteins, stimulation of smooth muscle cell growth, intima damage due to increased production of free oxygen radicals) and thrombophilia (inhibition of prostacyclin, inhibition of activation of plasminogen, inhibition of activation of protein C) (7). In heterozygotes, MTHFR enzyme activity might be reduced to 50%, whereas in homozygotes a residual activity of up to 20% is possible, depending on the mutation. The prevalence of MTHFR homozygotes in healthy populations is up to 16.5% (8). In children and adolescents atherosclerosis promoted by MTHFR mutations is probably not as important as the prothrombotic coagulation alterations. Our patient had no other thrombophilic risk factors (like overweight, high age, pregnancy, anti-phospholipid syndrome, smoking, etc.) except the intake of oral contraceptives. In the study by Pezzini et al. young patients with MTHFR mutations had a four times increased risk of a thromboembolic event compared to healthy controls, and equal to the risk of healthy persons taking oral contraceptives (9). Slooter et al. investigated whether the effect of MTHFR mutations may be potentiated by the use of oral contraceptives. They found that the MTHFR 677CT mutation is an independent risk factor of ischaemic stroke and their data suggest a high relative risk of ischaemic stroke for MTHFR mutation in combination with the use of oral contraceptives (10). Our