Physiological Definition Research Articles

CARDIOVASCULAR DERANGEMENT IN NEONATAL HERPES INFECTION

Abstract BACKGROUND Disseminated Herpes Simplex infection is a severe neonatal illness with high mortality and morbidity. Despite acyclovir treatment, the fulminant disease may be rapidly progressive and treatment is largely supportive. A significant proportion of neonates with this illness require intensive care support for circulatory insufficiency and hypoxic respiratory failure. Extracorporeal membrane oxygenation may be used as rescue therapy, though mortality remains high. The pathophysiological contributors to the disease phenotype, the mechanisms underlying the hemodynamic instability and therapeutic strategies to treat such cardiovascular dysfunction have not been well described. OBJECTIVES To describe patterns of cardiovascular dysfunction using targeted neonatal echocardiography and response to therapy for neonates with disseminated herpes infection in a quaternary neonatal intensive care unit. DESIGN/METHODS A cohort of all neonates with confirmed disseminated herpes simplex virus (HSV) infection admitted over the period of November 2014- April 2017 were included in this study. All neonates were evaluated by comprehensive targeted neonatal echocardiography (TnECHO) assessment within the first 24h of admission. Demographic and clinical features were collected retrospectively from the electronic medical record. All TnECHO measurements were performed by a single expert operator. Ethical approval was obtained from the institutional ethics board. RESULTS Five neonates, 3 with HSV 1 and 2 with HSV 2, were identified during the study period. All had features of profound circulatory insufficiency such as hypotension, metabolic acidosis with high lactate, oliguria/anuria, poor capillary refill etc. Three neonates had severe oxygenation failure. On functional echocardiographic assessment, we found that all cases demonstrated underfilled cardiac chambers and low cardiac outputs suggesting severe vasodilatation and third space losses. These cases were managed by aggressive volume resuscitation and use of peripheral vasoconstrictors such as Vasopressin and Nor-Epinephrine. Primary ventricular dysfunction was identified in 3 neonates, who were treated with dobutamine and/or epinephrine. Significant pulmonary hypertension was detected in three infants which prompted the use of Inhaled Nitric Oxide. Acyclovir was initiated early on. Significant cardiovascular stabilization could be achieved by such targeted hemodynamic therapy. However, in view of extensive neurological and hepatic damage, life sustaining therapy was eventually withdrawn in all of them. CONCLUSION Cardiovascular dysfunction in neonates with disseminated HSV infection may be due to either primary ventricular dysfunction, vasodilatation and third space losses or due to pulmonary hypertension. Early targeted neonatal echocardiography may enhance physiologic definition and facilitate targeted therapy. Mortality from multisystem complications, however, remains universal, which raises the question of the role of ECMO in this population.

Des tempéraments à l’idiosyncrasie : évolution et permanence d’une définition physiologique de l’individu

L’histoire des sciences permet de tracer l’apparition de concepts et de modèles théoriques venant supplanter ceux qui les ont précédés. Nous voudrions montrer que l’émergence d’une nouvelle définition théorique ne signifie pas toujours l’abandon de représentations ancrées dans la culture et même que, dans certains cas, elle contribue à les faire perdurer. Nous prenons ici comme exemple la notion d’idiosyncrasie, qui connaît une grande fortune à partir du xixe siècle.

Phenotyping Pharyngeal Pathophysiology using Polysomnography in Patients with Obstructive Sleep Apnea.

Therapies for obstructive sleep apnea (OSA) could be administered on the basis of a patient's own phenotypic causes ("traits") if a clinically applicable approach were available. Here we aimed to provide a means to quantify two key contributors to OSA-pharyngeal collapsibility and compensatory muscle responsiveness-that is applicable to diagnostic polysomnography. Based on physiological definitions, pharyngeal collapsibility determines the ventilation at normal (eupneic) ventilatory drive during sleep, and pharyngeal compensation determines the rise in ventilation accompanying a rising ventilatory drive. Thus, measuring ventilation and ventilatory drive (e.g., during spontaneous cyclic events) should reveal a patient's phenotypic traits without specialized intervention. We demonstrate this concept in patients with OSA (N = 29), using a novel automated noninvasive method to estimate ventilatory drive (polysomnographic method) and using "gold standard" ventilatory drive (intraesophageal diaphragm EMG) for comparison. Specialized physiological measurements using continuous positive airway pressure manipulation were employed for further comparison. The validity of nasal pressure as a ventilation surrogate was also tested (N = 11). Polysomnography-derived collapsibility and compensation estimates correlated favorably with those quantified using gold standard ventilatory drive (R = 0.83, P < 0.0001; and R = 0.76, P < 0.0001; respectively) and using continuous positive airway pressure manipulation (R = 0.67, P < 0.0001; and R = 0.64, P < 0.001; respectively). Polysomnographic estimates effectively stratified patients into high versus low subgroups (accuracy, 69-86% vs. ventilatory drive measures; P < 0.05). Traits were near-identical using nasal pressure versus pneumotach (N = 11, R ≥ 0.98, both traits; P < 0.001). Phenotypes of pharyngeal dysfunction in OSA are evident from spontaneous changes in ventilation and ventilatory drive during sleep, enabling noninvasive phenotyping in the clinic. Our approach may facilitate precision therapeutic interventions for OSA.

Deiodinases and stem cells: an intimate relationship.

Thyroid hormone is a major determinant of tissue functions in vivo. The deiodinase family controls the tissue-specific activation or inactivation of intracellular thyroid hormones. Precise control of the T3-dependent transcriptional program is required by multiple cell systems, including the stem cell. In this context, the identification of a close connection between thyroid hormones and different signal pathways involved in the control of stem cell functions suggested that the deiodinases may play a role in the definition of stem cell biology and physiology. Stem cells have an unlimited self-renewal capacity and the potential to differentiate into different types of mature cells. Deciphering how all these events are achieved, how the T3 signal is controlled and integrated in stem cells and their niches, and how it can impact on them is essentially unknown and represents a challenge for coming years. In this review, I will explore the role played by the deiodinases in the modulation of the TH signal in stem cells of adult tissues, namely muscle and intestine, and how their actions control the delicate balance among self-renewal, proliferation and differentiation. Elucidation of the molecular mechanisms presiding thyroid hormone action in stem cells may reveal therapeutic potential, for example in the fields of regenerative diseases and cancer.

The relationship between the basal coronary translesional pressure ratio and fractional flow reserve.

Fractional flow reserve (FFR) allows for physiological definition of coronary lesion severity but requires induction of maximal coronary circulation hyperemia with administration of adenosine leading to coronary resistive vessel vasodilatation. However, the hyperemic response to adenosine, and therefore the calculation of FFR, may be affected by dysfunction of the coronary microvasculature. The aim was to define the relationship between basal Pd /Pa and FFR and identify lesion-independent predictors of the change in Pd /Pa with hyperemia. One hundred and sixty-six consecutive patients undergoing FFR measurement were prospectively enrolled (mean age 62.6 ± 10.3 years, 27% females). Basal Pd /Pa , FFR, and delta Pd /Pa (difference between basal Pd /Pa and FFR) were recorded. Independent predictors of delta Pd /Pa included angiographic lesion severity, lesion length, gender, body mass index, and total cholesterol:HDL cholesterol ratio. The best basal Pd /Pa cutoff value to predict lesion physiological significance was 0.87 (positive predictive value of 100% for an FFR value ≤0.80) and the best cutoff for nonsignificance was 0.93 (negative predictive value of 98% for an FFR value >0.80). The delta Pd /Pa may be affected by patient gender, body mass index, and cholesterol profile. A basal Pd /Pa value of ≥0.93 is highly predictive of an FFR >0.80. Conversely, a basal Pd /Pa value of ≤0.87 is highly predictive of an FFR ≤0.80. © 2017 Wiley Periodicals, Inc.

Effects Of Prolonged, Fatiguing Exercise On Critical Power

The critical power (CP) is an important parameter of aerobic fitness and a strong predictor of endurance performance. Establishing how prolonged, fatiguing exercise may influence the CP is important for accurate performance prediction. PURPOSE: To assess the reliability of the CP in a fatigued state established using a 3-min all-out cycling test (3MT), and to assess the effects of fatigue on CP. METHODS: Subjects in Study 1 (n=6, 31 ± 6 yr, 76.8 ± 6.7 kg) and Study 2 (n=9, 29 ± 11 yr, 75.9 ± 7.1 kg) completed a ramp incremental test, a control 3MT test (C-3MT) and a 3MT immediately following 2 h of heavy-intensity constant work-rate (CWR) cycling (F-3MT). In Study 1 subjects performed the F-3MT condition twice. In Study 2 subjects completed 2 h of heavy exercise immediately followed by CWR exercise to exhaustion at 15 W above and below CP measured in F-3MT. Oxygen uptake (VO2) and blood [lactate] were measured during all tests. RESULTS: In Study 1, CP estimates from repeated F-3MTs were not different (test 1: 273 ± 52 W vs test 2: 276 ± 58 W; P >0.05), with an intraclass correlation coefficient of r=0.99 (P<0.05) and typical error of 5 W (2%). In Study 2, CP was lower in the F-3MT (282 ± 52 W) compared to C-3MT (306 ± 56 W; P<0.05). Four of nine subjects completed 30 min of exercise below F-3MT CP with sub-maximal steady state VO2 and blood [lactate] profiles, whereas five subjects exhibited steady state VO2 but non-steady state blood [lactate] and reached exhaustion in ~9-18 min. Subjects reached exhaustion in ~4-22 min when exercising above F-3MT CP. The VO2peak and end-exercise blood [lactate] were not different between exercise bouts performed above (4.05 ± 0.41 L·min-1) and below F-3MT CP (3.93 ± 0.50 L·min-1) but the VO2peak values were lower than the VO2max in the ramp incremental test (4.33 ± 0.52 L·min-1) (both P<0.05). CONCLUSION: The CP estimated in a 3-min all-out test evidenced high reliability in a fatigued state. We found that exercise in close proximity below the CP in the fatigued state was not sustainable beyond ~18 min and did not exhibit steady state blood [lactate] profiles. The VO2 responses during exercise above and below CP were characterised by inability to attain the same VO2max as in the rested state. These findings suggest that the well-characterised physiological definition of the CP is altered under conditions of extreme fatigue.

COPD and bronchiectasis – a real phenotype?

Bronchiectasis is an anatomical diagnosis, arising from a diverse range of mechanisms conceptualised as a 'vicious cycle' and ultimately resulting in permanently dilated airways. COPD is a physiological diagnosis – the end result of a susceptible individual being exposed to sufficient airborne environmental toxin. Confusion between COPD and bronchiectasis arises because of the potential for a similar clinical presentation. However, when extensive, bronchiectasis can result in fixed airflow obstruction that meets the physiological definition for COPD and conversely, some patients with COPD have airway wall changes – typically airway wall thickening rather than dilation – which is commonly labelled as 'bronchiectasis'. Cue confusion, and talk of 'BCOS' – a bronchiectasis-COPD overlap syndrome. Whether you accept this or not, it is important to note that fixed airflow obstruction is associated with poor outcomes in bronchiectasis (FEV1 is a component of BSI and FACED), and airway wall changes have been associated with poor outcomes in COPD. Therapy differs significantly between COPD and bronchiectasis: this presentation will therefore argue that it IS important to distinguish the primary pathology.

Making microscopy count: quantitative light microscopy of dynamic processes in living plants.

Cell theory has officially reached 350 years of age as the first use of the word 'cell' in a biological context can be traced to a description of plant material by Robert Hooke in his historic publication 'Micrographia: or some physiological definitions of minute bodies'. The 2015 Royal Microscopical Society Botanical Microscopy meeting was a celebration of the streams of investigation initiated by Hooke to understand at the subcellular scale how plant cell function and form arises. Much of the work presented, and Honorary Fellowships awarded, reflected the advanced application of bioimaging informatics to extract quantitative data from micrographs that reveal dynamic molecular processes driving cell growth and physiology. The field has progressed from collecting many pixels in multiple modes to associating these measurements with objects or features that are meaningful biologically. The additional complexity involves object identification that draws on a different type of expertise from computer science and statistics that is often impenetrable to biologists. There are many useful tools and approaches being developed, but we now need more interdisciplinary exchange to use them effectively. In this review we show how this quiet revolution has provided tools available to any personal computer user. We also discuss the oft-neglected issue of quantifying algorithm robustness and the exciting possibilities offered through the integration of physiological information generated by biosensors with object detection and tracking.

Study progress of physiologic definition of bronchopulmonary dysplasia in preterm infants

Bronchopulmonary dysplasia (BPD) characterized as the abnormal development of premature lung and trachea influenced by perinatal factors is the most common respiratory disease in very premature infants, and is also one of the diseases confirmedly related to poor quality of life.With the advancement of neonatal research and the improvement in clinical care, more very premature infants with BPD survived to discharge.BPD is becoming the disease which both neonatologists and pediatricians should pay much attention to.The definition of BPD in recent years is in controversy.In this paper, the physiologic definition of BPD was comprehensively reviewed as a recently more accepted definition. Key words: Bronchopulmonary dysplasia; Physiology; Infant, preterm

Defining Airflow Obstruction.

Airflow obstruction has been defined using spirometric test results when the forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio is below a fixed cutoff (<70%) or lower limits of normal (LLN) from reference equations that are based on values from a normal population. However, similar to other positive or abnormal diagnostic test results that are used to identify the presence of disease, perhaps airflow obstruction should be defined based on the values of FEV1/FVC for a population of individuals with known disease such as chronic obstructive pulmonary disease (COPD). Unfortunately, we do not know such a distribution of values of FEV1/FVC for patients with COPD since there is no gold standard for this syndrome or condition. Yet, we have used this physiologic definition of airflow obstruction based on a normal population to identify patients with COPD. In addition, we have defined airflow obstruction as either being present or absent. Instead, we should use a different approach to define airflow obstruction based on the probability or likelihood that the airflow obstruction is present which in turn would give us the probability or likelihood of a disease state such as COPD.

Comparisons and Limitations of Current Definitions of Bronchopulmonary Dysplasia for the Prematurity and Respiratory Outcomes Program.

Bronchopulmonary dysplasia is the most common morbidity of prematurity, but the validity and utility of commonly used definitions have been questioned. To compare three commonly used definitions of bronchopulmonary dysplasia in a contemporary prospective, multicenter observational cohort of extremely preterm infants. At 36 weeks postmenstrual age, the following definitions of bronchopulmonary dysplasia were applied to surviving infants with and without imputation: need for supplemental oxygen (Shennan definition), National Institutes of Health Workshop definition, and "physiologic" definition after a room-air challenge. Of 765 survivors assessed at 36 weeks, bronchopulmonary dysplasia was diagnosed in 40.8, 58.6, and 32.0% of infants, respectively, with the Shennan, workshop and physiologic definitions. The number of unclassified infants was lowest with the workshop definition (2.1%) and highest with the physiologic definition (16.1%). After assigning infants discharged home in room air before 36 weeks as no bronchopulmonary dysplasia, the modified Shennan definition compared favorably to the workshop definition, with 2.9% unclassified infants. Newer management strategies with nasal cannula flows up to 4 L/min or more and 0.21 FiO2 at 36 weeks obscured classification of bronchopulmonary dysplasia status in 12.4% of infants. Existing definitions of bronchopulmonary dysplasia differ with respect to ease of data collection and number of unclassifiable cases. Contemporary changes in management of infants, such as use of high-flow nasal cannula, limit application of existing definitions and may result in misclassification. A contemporary definition of bronchopulmonary dysplasia that correlates with respiratory morbidity in childhood is needed. Clinical trial registered with www.clinicaltrials.gov (NCT01435187).

Chronic cerebrospinal venous insufficiency: pitfalls and perils of sonographic assessment.

Duplex sonography has been proposed as a diagnostic modality for detection of chronic cerebrovascular venous insufficiency, a recently proposed hypothesis of multiple sclerosis (MS) pathogenesis. We reviewed potential challenges of duplex sonography for diagnosis of chronic cerebrovascular venous insufficiency and used interim pooled data from a study aimed to apply cerebrovascular venous insufficiency criteria to a group of patients with MS and control patients without MS. Duplex sonography for chronic cerebrovascular venous insufficiency was performed in patients with MS and controls. Extracranial and deep cerebral veins were studied by using a published chronic cerebrovascular venous insufficiency protocol and criteria. Comparative imaging was performed to explore how physiologic factors and imaging techniques could affect key parameters. The effects of varying definitions on fulfilling chronic cerebrovascular venous insufficiency diagnostic criteria were also explored. Forty-two patients were enrolled. Twenty-five (60%) had a reduction in internal jugular vein cross-sectional area by 50% or more, cross-sectional area of 0.3 cm(2) or less, and/or a B-mode abnormality. No patients had reflux longer than 0.88 seconds in both sitting and supine positions, the presence of duplex sonographic reflux on transcranial Doppler imaging, or a larger internal jugular vein cross-sectional area in the sitting versus supine position. Fourteen patients (33.3%) had either a flap or septum, and 1 had a web. Collateral veins to the vertebral veins were identified in 14 of 42 patients (33.3%). The use of transcranial Doppler imaging versus quality Doppler profiles resulted in fewer patients meeting criteria for chronic cerebrovascular venous insufficiency. There are several important variables, including physiologic, technical, and criterion definitions, in the application of sonographic assessment of chronic cerebrovascular venous insufficiency that may affect diagnostic accuracy.

RESPIRATORY SUPPORT OF PRETERM INFANTS AFTER EXTUBATION: COMPARISON OF CLINICAL EFFICACY OF STANDART AND HIGH FREQUENCY NON-INVASIVE VENTILATION

In animal models nasal high frequency oscillatory ventilation appears to provide better development of immature lung causing less injury. This open randomized study compared the clinical efficacy of the standard (SV) and high frequency (HFV) non-invasive (nasal) ventilation after primary extubation of very preterm infants. The study included 24 very premature infants with birth weight ≤1500 gand respiratory distress syndrome. Before the first extubation infants were randomized into the main (n = 12) or control (n = 12) group. A certain mode of respiratory support was used according to the protocol for at least 72 hrs. The primary study outcome was the need for re-intubation within 72 hrs after the initial extubation. Mortality, incidences of bronchopulmonary dysplasia (BPD) and other important complications of prematurity were also compared in these groups. The frequency of re-intubation within the first 72 hrs. of non-invasive respiratory support was similar in both groups (41.67%). No differences were observed between the groups for the total duration of respiratory support as well. The incidence of BPD was twice higher in the group of infants who were treated using nasal HFV (main group) according to physiological definition, but this difference was not significant (2 cases (16.67%) compared to 1 case (8.33%) accordingly; p = 0.78). BPD incidences according to the clinical definition were similar in the both groups (5 cases - 41.67%). The use of high-frequency non-invasive ventilation after primary extubation of very preterm infants has no obvious clinical advantages over the extubation followed by standard non-invasive ventilation.

Innovative treatments for adults with obstructive sleep apnea.

Obstructive sleep apnea (OSA) affects one in five adult males and is associated with significant comorbidity, cognitive impairment, excessive daytime sleepiness, and reduced quality of life. For over 25 years, the primary treatment has been continuous positive airway pressure, which introduces a column of air that serves as a pneumatic splint for the upper airway, preventing the airway collapse that is the physiologic definition of this syndrome. However, issues with patient tolerance and unacceptable levels of treatment adherence motivated the exploration of other potential treatments. With greater understanding of the physiologic mechanisms associated with OSA, novel interventions have emerged in the last 5 years. The purpose of this article is to describe new treatments for OSA and associated complex sleep apnea. New approaches to complex sleep apnea have included adaptive servoventilation. There is increased literature on the contribution of behavioral interventions to improve adherence with continuous positive airway pressure that have proven quite effective. New non-surgical treatments include oral pressure devices, improved mandibular advancement devices, nasal expiratory positive airway pressure, and newer approaches to positional therapy. Recent innovations in surgical interventions have included laser-assisted uvulopalatoplasty, radiofrequency ablation, palatal implants, and electrical stimulation of the upper airway muscles. No drugs have been approved to treat OSA, but potential drug therapies have centered on increasing ventilatory drive, altering the arousal threshold, modifying loop gain (a dimensionless value quantifying the stability of the ventilatory control system), or preventing airway collapse by affecting the surface tension. An emerging approach is the application of cannabinoids to increase upper airway tone.

IS-003 Early Inhaled Corticosteroids For The Prevention Of Bronchopulmonary Dysplasia In Extremely Preterm Infants: The Neonatal European Study Of Inhaled Steroids (neurosis)

Background Survival of extremely low birth weight (ELBW) infants has improved in recent decades but bronchopulmonary dysplasia (BPD) remains a major problem. The effect of early inhalation of corticosteroids on survival without BPD in these infants is unclear. Objective To determine the effect of early use of inhaled budesonide in infants with gestational ages of 23 0/7–27 6/7 weeks requiring any form of positive pressure support on survival without BPD at 36 weeks’ gestational age. Methods Randomised controlled trial. Budesonide or placebo were continued until infants were either off supplementary oxygen and positive pressure support or had reached a gestational age of 32 0/7 weeks regardless of their ventilator status. The primary outcome was death before 36 weeks of gestational age or survival with BPD, defined according to the physiological definition. Results We randomly assigned 863 infants during the first 12 h of life in 40 centres in 9 countries to inhaled budesonide or placebo. In 7 infants consent was withdrawn. Of the 437 infants assigned to inhaled budesonide, 175 died or survived with BPD (40.0%), as compared with 194 of 419 infants assigned to placebo (46.3%). Further results are shown in the table. Conclusions The reduction of the primary outcome (death before 36 weeks or BPD) by inhaled budesonide in ELBW infants was of borderline statistical significance. Inhaled budesonide significantly reduced BPD, which is a component of our primary outcome and was a predefined secondary outcome.

PO-0766 Exploring A Physiological Definition For Bronchopulmonary Dysplasia

Background and aims Current definitions for bronchopulmonary dysplasia (BPD) lack objectivity. A physiological definition for BPD where the level of shunt and the reduction in ventilation-perfusion ratio serve as an objective grading of severity has been suggested. Shunt and reduced VA:Q can be measured non-invasively by determining the relationship of arterial oxygen saturations (SpO2) to the fraction of inspired oxygen (FiO2). Our aims were to: 1. quantify shunt and reduced VA:Q in infants with BPD and in preterm infants without BPD. 2.correlate shunt and VA:Q to clinical grading of severity where possible Methods The group study population consisted of 10 infants (two with ‘No BPD’, two with ‘Mild BPD’ and six with ‘Severe BPD’) based on the NIH grades of BPD severity. Stepwise alterations in FiO2 were made, whilst ensuring infants stayed within the Monash Newborn SpO2 alarm limits. A two compartmental model of gas exchange was used to derive the SpO2 vs. FiO2 curves and values for shunt and VA:Q. Results Five out of six infants with ‘Severe BPD’ and one infant with ‘Mild BPD’ had VA:Q well below normal, range 0.34 to 0.56. Two infants with ‘No BPD’ and two infants with BPD, had SpO2 vs. FiO2 curves suggesting no impairment in gas exchange. The level of shunt and reduction in VA:Q did not consistently reflect the clinical grading of BPD. Conclusions Our results reinforce the need for a more objective definition of BPD as the possibility of misclassification using the clinical definition occurred on three occasions.

A New Approach to Homeostatic Regulation: Towards a Unified View of Physiological and Ecological Concepts

Stoichiometric homeostasis is the ability of an organism to keep its body chemical composition constant, despite varying inputs. Stoichiometric homeostasis therefore constrains the metabolic needs of consumers which in turn often feed on resources not matching these requirements. In a broader context, homeostasis also relates to the capacity of an organism to maintain other biological parameters (e.g. body temperature) at a constant level over ambient environmental variations. Unfortunately, there are discrepancies in the literature and ecological and physiological definitions of homeostasis are disparate and partly contradictory. Here, we address this matter by reviewing the existing knowledge considering two distinct groups, regulators and conformers and, based on examples of thermo- and osmoregulation, we propose a new approach to stoichiometric homeostasis, unifying ecological and physiological concepts. We suggest a simple and precise graphical way to identify regulators and conformers: for any given biological parameter (e.g. nutrient stoichiometry, temperature), a sigmoidal relation between internal and external conditions can be observed for conformers while an inverse sigmoidal response is characteristic of regulators. This new definition and method, based on well-studied physiological mechanisms, unifies ecological and physiological approaches and is a useful tool for understanding how organisms are affected by and affect their environment.

Evolution evolves: physiology returns to centre stage

Denis Noble, Eva Jablonka, Michael J. Joyner, Gerd B. Muller and Stig W. Omholt University of Oxford, Department of Physiology, Anatomy and Genetics, Oxford, UK Tel Aviv University, Cohn Institute for the History andPhilosophyof Science and Ideas, Ramat Aviv, Israel Mayo Clinic, Rochester, MN, USA University of Vienna, Department of Theoretical Biology, Vienna, Austria Norwegian University of Science and Technology, Faculty of Medicine, Trondheim, Norway

Guidelines for recognition, assessment and treatment of pain: WSAVA Global Pain Council members and co-authors of this document:.

Karol Mathews DVM DVSc DACVECC (Canada) Peter W Kronen Dr Vet Med, DVM DECVAA (Switzerland) Duncan Lascelles BSc BVSc PhD DSAS DECVS DACVS MRCVS (USA) Andrea Nolan MVB DVA PhD DECVAA DECVPT MRCVS (UK) Sheilah Robertson BVMS (Hons) PhD DACVAA DECVAA DECAWBM (WSEL) DACAW MRCVS (USA) Paulo VM Steagall MV MS PhD DACVAA (Brazil/Canada) Bonnie Wright DVM DACVAA (USA) Kazuto Yamashita DVM MS PhD DJCVS (Japan)

Impaired growth at birth and bronchopulmonary dysplasia classification: beyond small for gestational age.

To correlate intrauterine and postnatal growth with bronchopulmonary dysplasia (BPD) classification at 36 weeks postmenstrual age (PMA). A retrospective cohort design reviewing medical records for infants < 29 weeks gestational age (GA) born between 2008 and 2010. BPD classification using physiological definition at 36 weeks PMA and growth parameters at birth and 36 weeks PMA were compared between GA subgroups. The cohort consisted of 140 infants. Median GA and birth weight (BW) were 27 weeks and 918 g, respectively. Twenty percent of infants had no BPD, 27% had mild BPD, 31% had moderate BPD, and 22% had severe BPD. While BW and GA remain major factors associated with severe BPD, we did not observe differences in weights at 36 weeks PMA. Length and head circumference were significantly impaired in infants born < 26 weeks GA at birth and 36 weeks PMA. Most importantly, all infants born < 26 weeks GA below the 25th percentile for weight developed moderate/severe BPD. Infants born < 26 weeks GA were smaller at birth and had significant postnatal growth impairment in linear and head circumference growth. Risk of developing BPD associated with lower BW for GA appeared to occur beyond the traditional small-for-gestational age (SGA) classification.