Formula for the prediction of apnea / hypopnea index in children with obstructive sleep apnea without polysomnography according to the clinical parameters: Is it reliable?

PURPOSE OF THE STUDY: The aim of the study was to propose "the risk formula" for obstructive sleep apnea in children according to the general and local clinical parameters and findings relevant for obstructive sleep apnea (OSA) severity. The unmet need for this formula arises from the economic burden of polysomnography (device, staff, training, special sleep centers, etc) as the golden standard for the diagnostics. MATERIALS AND METHODS USED: The study was performed from January 2013 until January 2016 in the Sleep Center, Department for Neuroscience, School of Medicine of the University of Split, Department of Pediatrics, University Hospital Split, Croatia and ENT Dept. University Hospital in Split, Croatia. Inclusion criteria were: age > two years, AHI >1 diagnosed by polysomnography. Exclusion criteria were: chronic lung disease, active tonsillitis/pharyngitis at the time of the physical exam and syndromes that affect breathing. All polysomnograms were scored by a qualified sleep technologist and interpreted by two board certified sleep physicians independently. Age, sex, BMI, Mallampati score, tonsillar size and adenoids size were recorded. All statistical calculations were performed using SPSS 20. RESULTS: In total 60 children were included in the study. The median of age was 5 years (range 2-9). There were 19 (32%) girls and 41 (68%) boys. Of all evaluated predictors, there were statistically significant differences in the values of AHI among children with different modified Mallampati score (χ2 = 28.2; p < 0.001), different size of tonsils (χ2 = 25.3; p < 0.001) and different size of adenoids (z = 2.7; p = 0,006) in univariate regression analysis. Strong positive association of AHI with modified Mallampati score (standardized B = 0.51; partial correlation = 0.542, r = 0.631) was found, as well as positive correlation of AHI with tonsillar size (standardized B = 0.246; partial correlation = 0.295,R = 0.489) in the multivariate forward stepwise regression analysis. CONCLUSION: Even though we are aware that PSG is the gold standard for diagnostics of SDB there is a significant financial burden for this diagnostic procedure. That is why there is a necessity for establishing good clinical standards and possible formula for OSA severity evaluation. We propose formula which includes Mallampati score and tonsillar size for OSA -risk calculation in order to perform early therapeutic intervention thereby reducing the risk of long-term negative consequences. We recommend this formula as the screening formula in circumstances where PSG is not available, in cases when the "waiting list" is too long or when a child can not cooperate to perform it. In developing countries like Croatia on time intervention with reduced procedure-associated costs is of the utmost importance.

Lateral thermal damage to rat abdominal wall after harmonic scalpel application.

BACKGROUND: Use of the Harmonic Scalpel transduces a lower amount of energy to tissues, thereby limiting the potential for lateral thermal damage and deep penetration because only low temperatures are reached. The working principle of the Harmonic Scalpel is the transformation of electric power into the longitudinal mechanical movement of the instrument tip. This study aimed to determine the effects from varying durations of Harmonic Scalpel application on the experimental model of rat abdominal wall without skin. METHODS: After the rats had been anesthetized, and a laparotomy was performed. The Harmonic Scalpel shears were used on the muscular part of the abdominal wall without skin. Different durations of output power 3 were applied: a single 5-s application, a single 10-s application, and a regimen of two sequential 5-s applications. Each animal in each group of 10 received five individual activations, after which the animals were killed. Tissue samples were fixed and embedded in paraffin before sections were taken and stained. Using light microscopy and morphometric imaging analysis, the width of tissue lateral thermal damage was measured from the point of Harmonic Scalpel incision. RESULTS: The rat abdominal wall showed lateral thermal damage over a mean width of 0.0522 +/- 0.0097 mm after a 5-s Harmonic Scalpel application, a damage width of 0.1544 +/- 0.0419 mm after a 10-s application, and a damage width of 0.1020 +/- 0.0430 mm after a 5-s application followed by 5 s of inactivity and another 5 s of activity. These differences in thermal damage width between all the groups are statistically significant. CONCLUSIONS: The findings lead to the conclusion that tissue lateral thermal damage after Harmonic Scalpel application at standard output power is greater when a longer sustained period of application is used. Lateral thermal damage also is greater if the Harmonic Scalpel application time is continuous rather than of the same total duration with a brief midpoint interruption.

Effect of maternal hyperoxygenation on experimentally produced uteroplacental insufficiency in the rat.

The paper examines the effects of maternal hyperoxygenation on uteroplacental insufficiency produced by ligation of the uterine artery. Maternal hyperoxygenation did not significantly affect experimentally produced growth retardation or survival of the fetuses from the ligated horn. Analysis of the vascular anatomy revealed that additional oxygen improves the survival of fetuses compromised by uteroplacental insufficiency only in the presence of anastomosis between the uterine and ovarian arteries. The study demonstrated the importance of that anastomosis in evaluating the results obtained by this experimental model.

Morphological diversity of dying cells during regression of the human tail.

During normal human development a number of transient structures form and subsequently regress completely. One of the most prominent structures that regress during development is the human tail. We report here a histological and ultrastructural study of cell death in the cranial and caudal (tail) parts of the neural tube in 4 to 6-week-old human embryos. Initially, the human tail is composed of tail bud mesenchyme which differentiates into caudal somites, secondary neural tube, notochord and tail gut. Later on, these structures gradually regress by cell death. During the investigated period, we observed two morphologically distinct types of dying cells. The well-described apoptotic type of cell death was observed only in the cranial neural tube that forms during primary neurulation. The other type of cell death characterized by necrotic morphology was observed in the tail mesenchyme and in the caudal neural tube that forms during secondary neurulation. This morphological diversity suggests that besides differences in origin and fate there are different mechanisms of developmental cell death between two parts of the human neural tube. We can speculate that the apoptotic type of cell death is associated with the precise control of cell numbers and that the other morphologically distinct type of cell death is responsible for the massive removal of transitory structures.

Envenomation by the horned viper (Vipera ammodytes L.).

Snake venom poisoning is a medical emergency that requires urgent therapeutic procedures. The treatment of venomous snakebites is still controversial because of unclear therapeutic modalities. Choice of treatment is dictated in part by regional characteristics with regard to patient population and types of venomous snakes. The purpose of the study presented here was to report regional experience with venomous snakebites and to describe first-aid, pre-hospital, and hospital therapeutic procedures for horned viper bite. During a 16-year period, from 1980 to 1996, at the Clinical Hospital Split (Croatia) we collected data on 389 victims of horned viper bite. Incidence of the local and general complications is presented. We also reviewed therapeutic modalities and outcome with special attention to compartment syndromes and the indications for fasciotomy.

Fibronectin expression in the developing human spinal cord, nerves, and ganglia.

AIM: Analysis of developmental role of fibronectin during differentiation of the human spinal cord, nerves, and ganglia. METHODS: Seven normal human embryos and fetuses between the 7th and 9th developmental week and a 9-week fetus with cervical spina bifida were histologically examined on hematoxylin and eosin stained serial paraffin sections of thoracic axial segments. Monoclonal antibody to the human cell fibronectin fragment was used for immunohistochemical detection of fibronectin. RESULTS: In the 7th and 8th week of development, fibronectin was weakly expressed in the ventricular and intermediate zones of the spinal cord. Intense fibrillar expression was found in the marginal zone of the spinal cord - first over the ventral gray horns and later over the lateral and dorsal gray horns, and along the pathways of ventral and dorsal roots of the spinal nerves and in the spinal ganglia. At 9th week, fibronectin expression disappeared in the ventricular and intermediate zones a nd became weak and granular in the marginal zone of the spinal cord. In the spinal cord of a 9-week malformed fetus with cervical spina bifida, fibronectin expression was completely absent. Fibronectin was expressed in the nerves and ganglia throughout the investigated period, both in normal and malformed human conceptuses. CONCLUSION: Transient expression of fibronectin in the human spinal cord coincided with the most intense neuronal differentiation. Temporal and spatial expression of fibronectin during normal development, and its absence in a malformed human fetus suggests developmental role of fibronectin for the normal formation of the spinal cord.

Morphological characteristics of dying cells in axial structures of developing human embryos.

Programmed cell death (PCD) is a widespread phenomenon in the development of vertebrates. In most cases, dying cells during development exhibit generalized morphological features typical of apoptosis. We analyzed the morphological features of dying cells in the developing axial structures of 5 human embryos between 5 and 8 weeks of postovulatory age. Cell death in the axial structures, i.e. spinal cord, notochord and surrounding mesenchyme and somites, was analyzed using light and electron microscopy. Tissue samples were taken from the cervicothoracic region of normal human conceptuses. Two morphological types of cell death were found: apoptosis which was characterized by round or semilunar nuclear chromatin condensations, condensation and shrinkage of the cytoplasm and formation of apoptotic bodies, and cell death without the morphological features of apoptosis which was characterized by pyknotic nuclear chromatin condensations, vacuolated cytoplasm and the formation of numerous intercellular spaces. Apoptotic death occurred during the 5th week of normal development in all the axial structures. Later, apoptotic death appeared in all the axial structures, with the exception of the notochord, where some dying cells displayed features of secondary necrosis. According to our findings, apoptosis seems to be the most frequently observed type of PCD, but it is not the exclusive type of morphological cell death during the development of axial structures in human embryos.