Pulmonary Gas Exchange

SUMMARYHumboldt penguins Spheniscus humboldti in captivity and free-living Magellanic penguins S. magellanicus were fitted with loggers to determine beak angles during breathing. The Humboldt penguins were also fitted with masks for determining rates of air flow during breathing. During periods of higher gas exchange requirement, Humboldt penguins opened their beaks during inspiration, where tidal volume was linearly correlated with both change in beak angle and maximum beak angle, closed them slightly during the final stages of inspiration and finally closed them during expiration. Substantial differences were apparent between individuals. Contrary to the condition proposed for most birds, our data suggest that expiration is passive during periods of high respiratory tidal volumes, and that the increased resistance of the respiratory pathway serves to slow air flow so as to maximize gas exchange in the lungs. During foraging, Magellanic penguins at the surface between dives showed ...

Cardiopulmonary exercise testing (CPET) is a methodology that has profoundly affected the approach to patients' functional evaluation, linking performance and physiological parameters to the underlying metabolic substratum and providing highly reproducible exercise capacity descriptors. This study provides professionals with an up-to-date review of the rationale sustaining the use of CPET for functional evaluation of cardiac patients in both the clinical and research settings, describing parameters obtainable either from ramp incremental or step constant-power CPET and illustrating the wealth of information obtainable through an experienced use of this powerful tool. The choice of parameters to be measured will depend on the specific goals of functional evaluation in the individual patient, namely, exercise tolerance assessment, training prescription, treatment efficacy evaluation, and/or investigation of exercise-induced adaptations of the oxygen transport/utilization system. The full potentialities of CPET in the clinical and research setting still remain largely underused and strong efforts are recommended to promote a more widespread use of CPET in the functional evaluation of cardiac patients. Eur J Cardiovasc Prev Rehabil 00:000-000

Background Optimizing perioperative mechanical ventilation remains a significant clinical challenge. Experimental models indicate that "noisy" or variable ventilation (VV)--return of physiologic variability to respiratory rate and tidal volume--improves lung function compared with monotonous control mode ventilation (CV). VV was compared with CV in patients undergoing abdominal aortic aneurysmectomy, a patient group known to be at risk of deteriorating lung function perioperatively. Methods After baseline measurements under general anesthesia (CV with a tidal volume of 10 ml/kg and a respiratory rate of 10 breaths/min), patients were randomized to continue CV or switch to VV (computer control of the ventilator at the same minute ventilation but with 376 combinations of respiratory rate and tidal volume). Lung function was measured hourly for the next 6 h during surgery and recovery. Results Forty-one patients for aneurysmectomy were studied. The characteristics of the pati...

Based on literature in Adult Respiratory Distress Syndrome in humans and evidence of surfactant activation in vitro and vivo, and our clinical observations of secondary respiratory decompensation in premature infancies recovering from RDS, a study was designed to look at the possibility of benefit from secondary surfactant administration in premature infancies with secondary decompensation after recovery from respiratory distress syndrome (RDS). A prospective pilot study was performed to study the effects of secondary surfactant administration on oxygenation, ventilation and pulmonary function of neonates who had respiratory decompensation after recovery from RDS. A secondary data analysis was performed looking at pulmonary function related to ventilatory efficiency index (VEI), modified ventilatory index (MVI) and respiratory severity score (RSS). Entry criteria included infants admitted with RDS who were 7 days to 3 months of age, with birth weights ≥ 500 grams. Infants qualified ...

At the onset of muscular exercise, the kinetics of pulmonary O2uptake (V̇o2P) reflect the integrated dynamic responses of the ventilatory, circulatory, and neuromuscular systems for O2transport and utilization. Muscle O2uptake (V̇o2m) kinetics, however, are dissociated from V̇o2Pkinetics by intervening O2capacitances and the dynamics of the circulation and ventilation. We developed a multicompartment computational model (MCM) to investigate these dynamic interactions and optimized and validated the MCM using previously published, simultaneously measured V̇o2m, alveolar O2uptake (V̇o2A), and muscle blood flow (Q̇m) in healthy young men during cycle ergometry. The model was used to show that 1) the kinetics of V̇o2Aduring exercise transients are very sensitive to preexercise blood flow distribution and the absolute value of Q̇m, 2) a low preexercise Q̇mexaggerates the magnitude of the transient fall in venous O2concentration for any given V̇o2mkinetics, necessitating a tighter couplin...

Background: The aim of this study was to define clinical characteristics of patients with COPD and PH with particular attention on subgroup which have PH “out of proportion”, investigating the differences in term of inflammatory and oxidative stress status. Materials and Methods: Patients with COPD and low level of oxygen (PaO2 2), who showed, at echocardiographic study, PAPs > 30 mmHg without left heart systolic and diastolic dysfunction underwent to Right Heart Catheterization (RHC) to evaluate pulmonary pressures. The assay for human IL-6, LTB4, VIP and ET-1 were performed on blood sample taken during RHC in pulmonary artery. Results: 83 patients were enrolled and divided in three groups: simple COPD when mPAP was less then 25 mmHg (37 pz); COPD with PH if mPAP > 25 mmHg (46 pz) and among these last ones who had mPAP >35mmHg and FEV1 Patients with PH were older and had a BMI higher than others groups, moreover they had lower FEV1 and DLCO. Despite these differences, lowe...

Objective: To explore the consequences of helium/oxygen (He/O 2 ) inhalation on respiratory mechanics, gas exchange, and ventilation-perfusion (VA/Q) relationships in an animal model of severe induced bronchospasm during mechanical ventilation. Design: Prospective, interventional study. Setting: Experimental animal laboratory, university hospital. Interventions: Seven piglets were anesthetized, paralyzed, and mechanically ventilated, with all ventilator settings remaining constant throughout the protocol. Acute stable bronchospasm was obtained through continuous aerosolization of methacholine. Once steady-state was achieved, the animals successively breathed air/O 2 and He/O 2 (FIO 2 0.3), or inversely, in random order. Measurements were taken at baseline, during bronchospasm, and after 30 min of He/O 2 inhalation. Results: Bronchospasm increased lung peak inspiratory pressure (49±6.9 vs 18±1 cm H 2 O, P<0.001), lung resistance (22.7±1.5 vs 6.8±1.5 cm H 2 O.l -1 .s, P<0.001), dynamic elastance (76±11.2 vs 22.8±4.1 cm H 2 O.l -1 , P<0.001), and work of breathing (1.51±0.26 vs 0.47±0.08, P<0.001). Arterial pH decreased (7.47±0.06 vs 7.32±0.06, P<0.001), PaCO 2 increased, and PaO 2 decreased. Multiple inert gas elimination showed an absence of shunt, substantial increases in perfusion to low VA/Q regions, and dispersion of VA/Q distribution. He/O 2 reduced lung resistance and work of breathing, and worsened hypercapnia and respiratory acidosis. Conclusions: In this model, while He/O 2 improved respiratory mechanics and reduced work of breathing, hypercapnia and respiratory acidosis increased. Close attention should be paid to monitoring arterial blood gases when He/O 2 is used in mechanically ventilated acute severe asthma.

Objective: To compare the effects of He/O 2 and external PEEP (PEEPe) on intrinsic PEEP (PEEPi), respiratory mechanics, gas exchange, and ventilation/perfusion (V . A /Q . ) in mechanically ventilated COPD patients. Design and setting: Prospective, interventional study in the intensive care unit of a university hospital. Interventions: Ten intubated, sedated, paralyzed, mechanically ventilated COPD patients studied in the following conditions: (a) baseline settings made by clinician in charge, air/O 2 , ZEEP; (b) He/O 2 , ZEEP; (c) air/O 2 , ZEEP; (d) air/O 2 , PEEPe 80% of PEEPi. Measurements at each condition included V . A /Q . by the multiple inert gas elimination technique (MIGET). Results: PEEPi and trapped gas volume were comparably reduced by He/O 2 (4.2±4 vs. 7.7±4 cmH 2 O and 98±82 vs. 217±124 ml, respectively) and PEEPe (4.4±1.3 vs. 7.8±3.6 cmH 2 O and 120±107 vs. 216±115 ml, respectively). He/O 2 reduced inspirato-ry and expiratory respiratory system resistance (15.5±4.4 vs. 20.7±6.9 and 19±9 vs. 28.8±15 cmH 2 O l -1 s -1 , respectively) and plateau pressure (13±4 vs. 17±6 cmH 2 O). PEEPe increased airway pressures, including total PEEP, and elastance. PaO 2 /FIO 2 was slightly reduced by He/O 2 (225±83 vs. 245±82) without significant V . A /Q . change. Conclusions: He/O 2 and PEEPe comparably reduced PEEPi and trapped gas volume. However, He/O 2 decreased airway resistance and intrathoracic pressures, at a small cost in arterial oxygenation. He/O 2 could offer an attractive option in COPD patients with PEEPi/dynamic hyperinflation.

In 90 patients referred to the pulmonary function laboratory for evaluation of hyperventilation syndrome (HVS) and in whom somatic causes of the complaints had been excluded, we investigated the degree of concordance between three widely applied diagnostic methods: 1) the standardized Nijmegen questionnaire on major daily complaints; 2) the reproduction of the same symptoms during the hyperventilation provocation test (HVPT); and 3) the responses of end-tidal CO2 fraction (FETCO2) during the HVPT. In 86% of the patients a concordance was found between Nijmegen questionnaire (i.e. score of 24/64 or more) and symptom reproduction during HVPT (i.e. recognition of at least 2 major daily complaints). Based on these combined data we made a definite diagnosis of HVS in 37 patients, of non-HVS in 40 patients, and we retained only a possible HVS in 13 patients. Each of the 16 complaints in the questionnaire contributed significantly to the distinction between HVS and non-HVS patients, and a ...

Electrical impedance tomography (EIT), as a monitoring tool of regional lung ventilation, is radiation-free imaging with high temporal resolution. The most important purpose of EIT is to visualize the distribution of tidal volume in different lung regions especially between dependent (dorsal in supine patients) and non-dependent (ventral in supine patients) regions. Many clinical studies evaluated the applicability of PulmoVista® 500 (Dräger Medical GmbH, Lübeck, Germany) and similar EIT devices in estimating optimal PEEP after recruitment maneuvers (RM) in lung healthy patients and acute respiratory distress syndrome (ARDS), ventilation distribution in cystic fibrosis, COPB, pneumonia and respiratory diseases syndrome in infants.

Trail running involves constant changes in terrain and slope, complicating the accurate assessment of energy expenditure during performance. This study aimed to examine the relationship between running power output (RPO), oxygen consumption (VO 2), carbon dioxide production (VCO 2), and energy expenditure per minute (EE min) across positive and negative slopes in trained trail runners under standardized laboratory conditions. Fifteen male trail runners performed five randomized 5 min treadmill runs at 70% of VO 2 maximal speed on-7%,-5%, 0%, +5%, and +7% slopes. VO 2 , VCO 2 , EE min , respiratory exchange ratio (RQ), heart rate (HR), and RPO were recorded. Statistical analysis included Shapiro-Wilk tests for normality, repeated-measures ANOVA to compare variables across slopes, and Spearman or Pearson correlations between RPO and physiological variables. Moderate to strong positive correlations were found between RPO and VO 2 (Rho = 0.80-0.84, p < 0.001) and between RPO and EE min (Rho= 0.74-0.87, p < 0.01) across all conditions. These findings suggest that RPO measured via a wearable device may reflect changes in energy expenditure and supports the integration of wearable power metrics into training and nutritional strategies for trail running. However, further studies in female athletes, outdoor settings, extreme slopes, and altitude conditions are needed to confirm the generalizability of these results.

Apneic oxygenation; pulmonary and cardiovascular effects Kolettas A, Grosomanidis V, Fyntanidou B, Kotzampassi K, Kolettas V, Theodosiadis P, Karakoulas K, Mitos G, Aidoni Z, Vasilakos D Apneic oxygenation is an adjunct „ventilation‟ technique that involves insufflation of oxygen at varying flows through a catheter that is inserted through the endotracheal tube and is positioned above the carina. Apneic oxygenation improves gas exchange efficiency and preserves the arterial oxygenation at an acceptable level. The understanding of the mechanism that is responsible for the sustained high alveolar and blood oxygenation levels requires the substantial knowledge of the physiology regarding the transport and exchange of alveolar gases. Application of apneic oxygenation may be necessary in some clinical situations, in which no movement of the chest or the lungs may be desirable, such as during cardiothoracic surgery or during some radiological procedures, in order to eliminate respiratory ...

The aim of this study was to assess the validity of VO2max prediction using retrograde extrapolation in a breath-bybreath (BxB) gas measurement system. A retrospective study was performed, analysing 31 incremental and maximal stress tests carried out in our laboratory, corresponding to male subjects who practised different sporting activities (age: 29.9 ± 14.45 years; height: 174.4 ± 6.5 cm; weight: 71.4 ± 7.2 kg). A linear regression of the first minute of recovery was used to obtain extrapolated VO2max data and, subsequently, a correction equation was applied that provided predicted VO2max values. Given the variability of data in BxB measurement systems, extrapolated values can be expected to vary significantly from those actually measured, but differences disappeared in the predicted values, which were almost identical to those measured. This method enables stress tests to be performed without having to record gas measurements until the end. It could be useful for the validation of specific field tests, measuring VO2 trackside after the test, during recovery.

The purpose of this study was to evaluate the reliability of the VmaxST portable metabolic measurement system. Forty-five healthy adults (age = 25.7 ± 5.9 yr; height = 171.8 ± 9.1 cm; weight = 69.6 ± 12.8 kg; VO 2 peak = 40.7 ml/kg/min; percent fat = 21.7 ± 11.0) performed two separate and identical exercise routines on different days consisting of treadmill walking at 2.0 mph (53.6 m/min), 3.0 mph (80.5 m/min), and 4.0 mph (107.3 m/min) and running at 6.0 mph (160.9 m/min). V E and gas exchange were measured continuously breath-to-breath. A random effects model on logtransformed data yielded coefficients of variation (CV) and intraclass correlation coefficients (ICC) for VO 2 and V E of 5.2-7.6%, and 0.77-0.92, respectively, for all walking and running trials. For VCO 2 , CVs were higher (10-12%) and ICCs lower (0.70-0.81). Ordinary least squares regression between the individual difference scores and the individual mean scores for V E , VO 2 and VCO 2 , respectively, indicated no systematic bias (all p > 0.05). Bland-Altman analysis also illustrated no systematic bias between repeated measurements. The VmaxST provides reliable measurements of VO 2 and V E duringduring walking and running eliciting V E and VO 2 at least up to ~56 and 2.2 l/ min, respectively. The system appears to be less reliable for measuring VCO 2 .

Carbogen is thought to be more effective than normobaric oxygen in reducing tumour hypoxia because it may reduce hyperoxic vasoconstriction. In this study, tumour and normal arteriolar diameters were measured simultaneously with perivascular pO2 during air breathing followed by either carbogen or 100% oxygen to determine whether the action of carbogen is the result of alterations in feeding vessel diameter. Fischer-344 rats bearing dorsal flap window chambers, with or without implanted R3230AC tumours, were the experimental subjects. Arteriolar diameters were measured using optical techniques and perivascular pO2 was measured using recessed-tip electrodes (3-6 microns tip diameter). Baseline arteriolar pO2 averaged 30-50% of blood gas pO2 (mean = 97 mmHg). Both hyperoxic gases increased blood gas pO2 by 4-to 5-fold, but relative improvements in arteriolar pO2 were < or = 2.5 for all arterioles studied. This means that these normobaric high O2 gases are not very efficient in increasing O2 delivery to tumours. In addition, improvements in tumour arteriolar pO2 were transient for both hyperoxic gases. Oxygen and carbogen caused no change and mild vasodilatory responses in tumour arterioles, respectively. Normal arterioles on the other hand, tended toward vasoconstriction by carbogen breathing. Peri-arteriolar pO2 in tumours increased within the first 5 min of breathing either hyperoxic gas, followed by a decline back toward values seen with air-breathing. These results suggest that temporal changes in tumour oxygenation after exposure to carbogen or O2 may not be due to changes in perfusion. Other factors, such as changes in O2 consumption rate may be involved.

Limited information exists regarding measurement, reproducibility and interrelationships of non-invasive biomarkers in smokers. We compared exhaled breath condensate (EBC) leukotriene B 4 (LTB 4 ) and 8-isoprostane, exhaled nitric oxide, induced sputum, spirometry, plethysmography, impulse oscillometry and methacholine reactivity in 18 smokers and 10 non-smokers. We assessed the relationships between these measurements and within-subject reproducibility of EBC biomarkers in smokers. Compared to non-smokers, smokers had signifi cantly lower MMEF % predicted (mean 64.1 vs 77.7, p = 0.003), FEV 1 /FVC (mean 76.2 vs 79.8 p = 0.05), specifi c conductance (geometric mean 1.2 vs 1.6, p = 0.02), higher resonant frequency (mean 15.5 vs 9.9, p = 0.01) and higher EBC 8-isoprostane (geometric mean 49.9 vs 8.9 pg/ml p = 0.001). Median EBC pH values were similar, but a subgroup of smokers had airway acidifi cation (pH Ͻ 7.2) not observed in non-smokers. Smokers had predominant sputum neutrophilia (mean 68.5%). Repeated EBC measurements showed no signifi cant differences between group means, but Bland Altman analysis showed large individual variability. EBC 8-isoprostane correlated with EBC LTB 4 (r = 0.78, p = 0.0001). Sputum supernatant IL-8 correlated with total neutrophil count per gram of sputum (r = 0.52, p = 0.04) and with EBC pH (r = -0.59, p = 0.02). In conclusion, smokers had evidence of small airway dysfunction, increased airway resistance, reduced lung compliance, airway neutrophilia and oxidative stress.

A method for the noninvasive measurement of airway responsiveness was validated in allergic BALB/c mice. With head-out body plethysmography and the decrease in tidal midexpiratory flow (EF50) as an indicator of airway obstruction, responses to inhaled methacholine (MCh) and the allergen ovalbumin were measured in conscious mice. Allergen-sensitized and -challenged mice developed airway hyperresponsiveness as measured by EF50to aerosolized MCh compared with that in control animals. This response was associated with increased allergen-specific IgE and IgG1 production, increased levels of interleukin-4 and interleukin-5 in bronchoalveolar lavage fluid and eosinophilic lung inflammation. Ovalbumin aerosol challenge elicited no acute bronchoconstriction but resulted in a significant decline in EF50baseline values 24 h after challenge in allergic mice. The decline in EF50to MCh challenge correlated closely with simultaneous decreases in pulmonary conductance and dynamic compliance. The de...

Background: Studies in thoracic surgery have long raised concerns that intraoperative administration of intravenous fluids exacerbates or causes postoperative complications and hence advocate fluid restriction. Methods: This retrospective 3-year study investigated the role of intraoperative crystalloid administration rates on the duration of postoperative hospital length of stay (phLOS) and on the incidences of previously reported adverse events (AEs) in 222 consecutive patients following thoracic surgery. Results: Higher rates of intraoperative crystalloid administration were significantly associated with shorter phLOS (P=0.0006) and with less variance in phLOS. Dose-response curves showed progressive decreases in the postoperative incidences of surgical, cardiovascular, pulmonary, renal, other, and long-term AEs with higher intraoperative crystalloid administration rates. The rate of intravenous crystalloid administration during thoracic surgery was significantly associated with duration of and variance in phLOS, and dose-response curves showed progressive decreases in the incidences of AEs associated with this surgery. We cannot confirm that restrictive intraoperative crystalloid administration benefits patients undergoing thoracic surgery.

Cardiac surgery with cardiopulmonary bypass (CPB) has advanced significantly, yet prolonged stays in the intensive care unit (ICU) after such surgeries remain a critical concern due to increased healthcare costs, resource strain, and heightened risk of complications. This study aimed to assess the risk factors associated with long ICU stays in patients after cardiac surgery with CP Bat the University of Benin Teaching Hospital. A descriptive cross-sectional survey design was employed, using a census sampling technique among 50 healthcare workers inthe hospital's cardiac ICU. Data were collected through a structured, validated questionnaire and analyzed using descriptive statistics. Results revealed that patient-specific factors, including advancedage, comorbidities, obesity, poor nutritional status, and reduced functional capacity,significantlycontribute to prolonged ICU stays.Additionally, postoperative complications such as respiratory issues, infections, acute kidney injury, bleeding, and arrhythmias were major determinants ofextended ICU admissions. In order to enhance outcomes and shorten ICU stays, the study's recommendations stress the need of preoperative patient optimization, early mobilization, adherence to standardized treatment procedures, and multidisciplinary team methods. According to the study's findings, early risk factor identification and treatment can improve recovery, lower medical expenses, and maximize the use of intensive care unit resources.It is advised that more study be done to examine strategies that can successfully reduce the length of stay in the intensive care unit following heart surgery.

Previous literature has shown that sedentary older women rely on peripheral adaptations to improve cardiorespiratory fitness with endurance training i.e. they show minimal increases in central parameters (cardiac output, Q) in response to endurance training. The purpose of this study therefore was to determine whether endurance trained older women were able to preserve maximal exercise Q and were characterized by a high stroke volume (SV) when compared to physically inactive older women. Trained (n = 7) and untrained (n = 1 0) women attended two maximal and one submaximal laboratory session. Breath-by-breath analysis was conducted using mass spectrometry and Q was assessed using acetylene open circuit inert gas wash-in. Multivariate analysis of variance and paired samples t-tests were used to determine between and within group differences. Trained women had a significantly higher VO2max (37.5 vs. 24.1 ml(-1)·kg·min(-1)) compared to untrained women. There were no differences for peri...

Rationale: In a pulmonary process characterized by spatially heterogeneous loss of aeration, the impairment of gas exchange is expected to depend on the regional distribution of perfusion relative to that of aeration. Objectives: To investigate how regional aeration, shunt, and perfusion are interrelated at different levels of end-expiratory pressure and how their interplay relates to global shunt fraction in acute lung injury. Methods: Regional shunt and perfusion were assessed by imaging with positron emission tomography the pulmonary kinetics of [ 13 N]nitrogen infused in saline solution in five sheep after lung lavage. The lung field was divided in six horizontal regions. Measurements and Main Results: Each animal showed an inverse relation between regional shunt (FS) and gas (FG) fractions: FS 5 2m Á FG 1 FS 0 . This relation was similar among animals (m 5 1.25 6 0.14, FS 0 5 0.75 6 0.15) and invariant with end-expiratory pressure, despite lack of correlation between global shunt and gas fractions and large interanimal variability in global shunt fraction. When this relation was used to estimate global shunt fraction as a perfusion-weighted average of the estimates of regional shunt fraction derived from regional gas fraction, 72% of the interanimal variability in global shunt fraction could be explained. Conclusions: Despite large interanimal variability in global shunt fraction, there was a consistent inverse relation between regional shunt and gas fractions, independent of end-expiratory pressure. Most of the interanimal variability in global shunt fraction could be explained by the combined effect of this relation and the distribution of perfusion on regional shunt, rather than by differences in global aeration.

Large animals havc a lower massspccific cost of transport than do small animals, but the ecological significance of this relationship is unclear (Taylor 197711). Bourliere (1975, p. 7) has stated that "the fact that a horse can move one gram of its body weight over one kilolnctrc morc chcaply than a mouse is another evolutionary advantage of a large body sizc." Such a vicw sccrns illogical at best. Animals do not live on a pet--gram basis but rather as intact individuals (cf. McNab 1971), and whole-animal transport costs arc, of course, greater for large animals than for small ones. In ordcr to consider the ecological relevance of transport cost allometry, 1 define the Ecological Cost of Transport (ECT) as the pcrcentagc of an animal's Daily Energy Expenditure (DEE) that is devoted to transport costs. Two questions must then be answered: (1) How does the ECT vary as a function of body mass? (2) What is the magnitude of the ECT? In naturc, many animals travel at speeds which elicit their maximal rate of oxygen consumption ( ~0 , m a x ; c.g.

To investigate single-day time-to-exhaustion (TTE) and time trial (TT) based laboratory tests values of critical power (CP), Wprime (W&#39;) and respective oxygen kinetics responses. Twelve cyclists performed a maximal ramp test followed by three TTE and three TT efforts interspersed by a 60-min recovery between efforts. Oxygen uptake was measured during all trials. The mean response time (MRT) was calculated as a description of the overall V̇O2 kinetic response from the onset to 2 min of exercise. TTE determined CP was 279 ± 52W and TT determined CP was 276 ± 50W (P = 0.237). Values of W&#39; were 14.3 ± 3.4 kJ (TTE W&#39;) and 16.5± 4.2 kJ (TT W&#39;) (P = 0.028). Whilst a high level of agreement (-12 to 17 W) and a low prediction error of 2.7% was established for CP, for W&#39; limits of agreements were markedly lower (-8 to 3.7 kJ) with a prediction error of 18.8%. The mean standard error for TTE CP values was significantly higher than that for TT CP values (2.4 ± 1.9% vs. 1.2 ±...

Background: It is mandatory for the clinicians to understand the events occurring in the Pediatric Intensive Care Unit (PICU) and outcome of mechanically ventilated children for improving the quality of care of the critically ill child. There are many factors which are associated with increased magnitude of mortality in ventilated children. Therefore this study will assess the overall characteristics and outcome of mechanically ventilated children aged 1month-18years at the University of Gondar Hospital, Pediatric Intensive Care Unit. Methods: Institution based retrospective cross-sectional study was conducted on 115 children admitted and mechanically ventilated at PICU of the University of Gondar Hospital from June2015 to September 2021.Data were collected by a structured data extraction tool from the medical records. Data analysis was done by using SPSS version 20. Both descriptive and analytical statistical procedures were utilized. To identify associated factors with the outcome, both bivariate and multi-variate logistic regression analysis were applied. The results of the regression analysis were reported as OR with their 95% con dence interval and signi cance of p-value below 0.2 and 0.05 in Bivariate and multi variate logistic regressions, respectively. .Result: The overall mortality was reported to be 54.8% and clinical characteristics of ventilated children showed that neurologic emergencies (coma)41(35.7%) and Mmalignancies which found in 20(17.4%) were the major reasons for mechanical ventilation. Frequently used mode was SIMV (79.1%) and CPAP was the preferred method of weaning (50%). The mortality rate of mechanically ventilated pediatric patients at the University of Gondar Hospital ,PICU was 54.8%. The main cause of death was Acute Respiratory Distress syndrome. SIMV was the main mode and ETT was the only way to access the airway. Severe Acute Malnutrition ,extubation during night and duration of PICU stay were signi cant predictors of PICU mortality.

Background: At the admission in rehabilitation program, some patients with chronic respiratory disease were asked by a health professional to to answer a questionnaire about their sexuality. The objectives of the study were 1) to determine if sexual problems occurred in patients with respiratory chronic disease ; 2) to assess if these survey problems were linked to respiratory disease; 3) to explore the motivation to speak about sexuality during rehabilitation program. Methods: 52 consecutive respiratory disease subjects (58.3 ± 9 yr; FEV1 = 65.5 ± 21 % predicted, mean ± SD) answered a sexuality questionnaire survey with rehabilitation team (psychologists, nurses, physiotherapists). This group comprised 26 men and 26 women. Results: 70% of patients estimated that respiratory disease had an impact on their sexuality. A visual analog scale showed that 62% of patients were not satisfied. The severity of obstruction (FEV1) was not correlated to satisfaction (r=.017, P=0.90), or frequenc...

Abstract: The histology of the accessory respiratory organ of the African catfish – dendretic organ was investigated to reveal its microanatomy. The data obtained will provide baseline data for further investigative research and assist fish pathologists. The histology showed that the tubular shaped dendretic organ was covered by stratified squamous epithelium containing periodic acid-Schiff (PAS) and alcian blue (AB) positive mucous cells. On most surfaces, the epithelial cells were organized into columns with mucous cells placed in-between the epithelial cell columns. At the tip of the surface, capillaries were lined by endothelium at the surface epithelium/air contact area. The subepithelial layer was of loose connective tissue containing adipose tissue and occasional blood vessels. The core of the dendretic organ contained elastic cartilage surrounded by a dense layer of perichondrium. Elastic fibres were observed the territorial and inter-territorial spaces.

The pharyngeal pad located dorsally on the oro-pharynx was processed for light microscopy. The epithelium was of stratified mucous type containing taste buds, club cells and teeth. The micromorphology revealed the co-localization of teeth and taste bud. Developing, erupting and erupted teeth were also seen. The thin bone of cancellous type with a marrow seen provided point of origin and insertion for the skeletal muscle present. Osteoblasts were seen on the surface of the cancellous bone probably depositing bone matrix. The pad had a base of hyaline cartilage. Stratum adiposum was observed and may be site for nutrient storage and also function in reducing friction between sliding muscle fibres since it was sandwiched between muscle fibres. The micromorphology suggest an organ used in trituration and selection of food by gustation. The blood vessels in the bone marrow suggest haematopoietic function. The bone and cartilage present is for support. Keywords: Pharyngeal pad, Histology, ...

A respiration-gated synchrotron radiation computed tomography (SRCT) technique, which allows visualization and direct quantification of inhaled stable xenon gas, was used to study the effect of tidal volume (Vt) on regional lung ventilation. High-resolution maps (pixel size 0.35 × 0.35 mm) of local washin time constants (τ) and regional specific ventilation were obtained in five anesthetized, paralyzed, and mechanically ventilated rabbits in upright body position at the fourth, sixth, and eighth dorsal vertebral levels with a Vt from 4.9 ± 0.3 to 7.9 ± 0.4 ml/kg (means ± SE). Increasing Vt without an increase in minute ventilation resulted in a proportional increase of mean specific ventilation up to 65% in all studied lung levels and reduced the scattering of washin τ values. The τ values had log-normal distributions. The results indicate that an increase in Vt decreases nonuniformity of intraregional ventilatory gas exchange. The findings suggest that (SRCT) provides a new quantit...

We aimed to describe the evolution in nursing diagnoses for children with congenital heart disease. This longitudinal study was carried out from July to November of 2004. The sample consisted of 45 children interned in a public hospital in Fortaleza, Brazil, followed during fifteen days. In this period, we accomplished six diagnostic evaluations and found 21 nursing diagnoses. Six of these showed greater oscillations in their occurrence over time: Ineffective breathing pattern, Activity intolerance, Ineffective airway clearance, Hyperthermia, Sleep pattern disturbance, Risk for activity intolerance. Five parametric models were constructed in the time domain, with a view to predicting the occurrence of the nursing diagnoses. Knowledge about the temporal evolution in individuals' responses can guide nursing care towards the client's real needs. DESCRIPTORS: heart defects, congenital; nursing diagnosis; continuity of patient care EVOLUCIÓN DE LOS DIAGNÓSTICOS ENFERMEROS DE NIÑOS CON CARDIOPATÍAS CONGÉNITAS Se objetivó describir la evolución de los diagnósticos enfermeros en niños portadores de cardiopatías congénitas. Estudio longitudinal desarrollado en los meses de julio a noviembre del 2004. La muestra fue compuesta por 45 niños ingresados en un hospital de la red pública del municipio de Fortaleza, Brasil, acompañados durante quince días de internamiento. En el período, llevamos a cabo seis evaluaciones diagnósticas, encontrando 21 diagnósticos enfermeros. Entre los diagnósticos, seis evidenciaron mayores oscilaciones en sus trayectorias de ocurrencia en el tiempo: Patrón respiratorio ineficaz, Intolerancia a la actividad, Limpieza ineficaz de las vías aéreas, Hipertermia, Deterioro del patrón de sueño y Riesgo de intolerancia a la actividad. Se construyeron cinco modelos paramétricos en el dominio del tiempo, con vistas a predecir la ocurrencia de esos diagnósticos enfermeros. Concluimos que el conocimiento de la evolución temporal de las respuestas del individuo puede dirigir los cuidados de enfermería para las reales necesidades del cliente. DESCRIPTORES: cardiopatías congénitas; diagnóstico de enfermería; continuidad de la atención al paciente EVOLUÇÃO DOS DIAGNÓSTICOS DE ENFERMAGEM DE CRIANÇAS COM CARDIOPATIAS CONGÊNITAS Objetivou-se descrever a evolução dos diagnósticos de enfermagem em crianças portadoras de cardiopatias congênitas. Estudo longitudinal desenvolvido nos meses de julho a novembro de 2004. A amostra foi composta por 45 crianças internadas em um hospital da rede pública do município de Fortaleza, acompanhadas durante quinze dias de internamento. No período efetivaram-se seis avaliações diagnósticas. Foram encontrados 21 diagnósticos de enfermagem. Entre os diagnósticos, seis evidenciaram maiores oscilações em suas trajetórias de ocorrência no tempo: Padrão respiratório ineficaz, Intolerância à atividade, Desobstrução ineficaz das vias aéreas, Hipertermia, Padrão de sono perturbado e Risco para intolerância à atividade. Foram construídos cinco modelos paramétricos no domínio do tempo, com vistas a predizer a ocorrência desses diagnósticos de enfermagem. Conclui-se que o conhecimento da evolução temporal das respostas do indivíduo pode direcionar os cuidados de enfermagem para as reais necessidades do cliente.

We aimed to describe the evolution in nursing diagnoses for children with congenital heart disease. This longitudinal study was carried out from July to November of 2004. The sample consisted of 45 children interned in a public hospital in Fortaleza, Brazil, followed during fifteen days. In this period, we accomplished six diagnostic evaluations and found 21 nursing diagnoses. Six of these showed greater oscillations in their occurrence over time: Ineffective breathing pattern, Activity intolerance, Ineffective airway clearance, Hyperthermia, Sleep pattern disturbance, Risk for activity intolerance. Five parametric models were constructed in the time domain, with a view to predicting the occurrence of the nursing diagnoses. Knowledge about the temporal evolution in individuals' responses can guide nursing care towards the client's real needs. DESCRIPTORS: heart defects, congenital; nursing diagnosis; continuity of patient care EVOLUCIÓN DE LOS DIAGNÓSTICOS ENFERMEROS DE NIÑOS CON CARDIOPATÍAS CONGÉNITAS Se objetivó describir la evolución de los diagnósticos enfermeros en niños portadores de cardiopatías congénitas. Estudio longitudinal desarrollado en los meses de julio a noviembre del 2004. La muestra fue compuesta por 45 niños ingresados en un hospital de la red pública del municipio de Fortaleza, Brasil, acompañados durante quince días de internamiento. En el período, llevamos a cabo seis evaluaciones diagnósticas, encontrando 21 diagnósticos enfermeros. Entre los diagnósticos, seis evidenciaron mayores oscilaciones en sus trayectorias de ocurrencia en el tiempo: Patrón respiratorio ineficaz, Intolerancia a la actividad, Limpieza ineficaz de las vías aéreas, Hipertermia, Deterioro del patrón de sueño y Riesgo de intolerancia a la actividad. Se construyeron cinco modelos paramétricos en el dominio del tiempo, con vistas a predecir la ocurrencia de esos diagnósticos enfermeros. Concluimos que el conocimiento de la evolución temporal de las respuestas del individuo puede dirigir los cuidados de enfermería para las reales necesidades del cliente. DESCRIPTORES: cardiopatías congénitas; diagnóstico de enfermería; continuidad de la atención al paciente EVOLUÇÃO DOS DIAGNÓSTICOS DE ENFERMAGEM DE CRIANÇAS COM CARDIOPATIAS CONGÊNITAS Objetivou-se descrever a evolução dos diagnósticos de enfermagem em crianças portadoras de cardiopatias congênitas. Estudo longitudinal desenvolvido nos meses de julho a novembro de 2004. A amostra foi composta por 45 crianças internadas em um hospital da rede pública do município de Fortaleza, acompanhadas durante quinze dias de internamento. No período efetivaram-se seis avaliações diagnósticas. Foram encontrados 21 diagnósticos de enfermagem. Entre os diagnósticos, seis evidenciaram maiores oscilações em suas trajetórias de ocorrência no tempo: Padrão respiratório ineficaz, Intolerância à atividade, Desobstrução ineficaz das vias aéreas, Hipertermia, Padrão de sono perturbado e Risco para intolerância à atividade. Foram construídos cinco modelos paramétricos no domínio do tempo, com vistas a predizer a ocorrência desses diagnósticos de enfermagem. Conclui-se que o conhecimento da evolução temporal das respostas do indivíduo pode direcionar os cuidados de enfermagem para as reais necessidades do cliente.

Objective: Although resection of giant bullae for the purpose of improving the function of underlying compressed lung is an accepted form of surgery for emphysema, there is only limited information regarding long-term improvement in dynamic hyperinflation and exercise tolerance. Our major goal was to investigate the effects of lung resection for giant bullae on pulmonary function, dynamic hyperinflation, and exercise capacity in patients with chronic obstructive pulmonary disease characterized by emphysema. Methods: Pulmonary function and exercise testing were assessed prospectively before and 3, 6, 12, 24, and 48 months after surgery in 12 patients who had chronic obstructive pulmonary disease with emphysema who underwent lung resection of giant bullae. Results: Forced expiratory volume, diffusing capacity for carbon monoxide, arterial partial pressure of oxygen, and exercise capacity were significantly increased after resection of surgical bullae. Dynamic hyperinflation, as assessed by reduction in inspiratory capacity and dyspnea Borg scale, were significantly decreased during exercise. Improvement in baseline and exercise functional capacity slightly decreased over time, remaining, however, far above the value before surgery. Altogether, these findings suggest that surgery for resection of giant bullae is an effective procedure for improving airflow, limiting gas exchange, and limiting exercise dynamic hyperinflation over time. T he resection of giant bullae in patients with chronic obstructive pulmonary disease (COPD) 1-3 for the purpose of improving the function of underlying compressed lung is an accepted form of surgery for emphysema. Patients with COPD who have bullae occupying up to 30% of the hemithorax, with evidence of compressed lung tissue underlying the bullae, usually undergo surgery. Outcomes in carefully selected patients appear to be positive, with surgical mortality ranging from 0% to 22.5%. Lung function testing at rest demonstrates early improvement of dyspnea and increases in forced expiratory volume in 1 second (FEV 1 ), ratio of forced expiratory volume in 1 second to forced vital capacity (FEV 1 /FVC), and diffusing capacity of the lung for carbon monoxide (DLCO). For example, in one of the largest series, long-term results of 84 patients who underwent surgical procedures for bullous emphysema indicate that the greatest improvement in FEV 1 , that is, 50% to 200%, was seen in patients with bullae that occupied up to 50% of the hemithorax. 5 Improvement in lung function appears durable in terms of symptom relief and pulmonary function testing. Elegant studies have recently reported that giant bullectomy appears to have been fairly safe and allowed clinical and functional improvement for years. This benefit of elective surgery in patients with giant bullous emphysema was evaluated in terms of dyspnea score, resting lung function, and quality of life. Although 6-minute walk From Explorations Fonctionnelles Respi-

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In this study, we aimed to define the effects of anesthesia and surgery on the resting energy expenditure of horses in experimental conditions. Six horses were used in a longitudinal study with 2 study periods: before and after anesthesia and surgery. Every horse underwent a standard 90-min ventral midline exploratory laparotomy. Oxygen uptake (VO2) and carbon dioxide output (VCO2) were measured, with the use of a closed-circuit spirometry system, on 5 consecutive days immediately before and after the surgery. In 3 consecutive 5-min periods each day, the expired air was collected in a Collins spirometer. Samples of the expired gas were drawn from the spirometer through a drying column into O2 and CO2 analyzers. Resting energy expenditure was calculated as [(VO2 STPD*3.94) + (VCO2 STPD*1.11)]*1.44. This study showed that anesthesia and ventral midline exploratory laparotomy in experimental conditions increase the postoperative caloric demand in horses by an average of 1.0 Mcal/d, whi...

Background: Dark chocolate (DC) is abundant in flavanols which have been reported to increase the bioavailability and bioactivity of nitric oxide (NO). Increasing NO bioavailability has often demonstrated reduced oxygen cost and performance enhancement during submaximal exercise. Methods: Nine moderately-trained male participants volunteered to undertake baseline (BL) measurements that comprised a cycle :V O 2max test followed by cycling at 80 % of their established gas exchange threshold (GET) for 20-min and then immediately followed by a two-minute time-trial (TT). Using a randomised crossover design participants performed two further trials, two weeks apart, with either 40 g of DC or white chocolate (WC) being consumed daily. Oxygen consumption, RER, heart rate and blood lactate (BLa) were measured during each trial. Results: DC consumption increased GET and TT performance compared to both BL and WC (P < 0.05). DC consumption increased :V O 2max by 6 % compared to BL (P < 0.05), but did not reach statistical significance compared to WC. There were no differences in the moderate-intensity cycling for :V O 2, RER, BLa and heart rate between conditions, although, :V O 2 and RER exhibited consistently lower trends following DC consumption compared to BL and WC, these did not reach statistical significance. Conclusion: Chronic supplementation with DC resulted in a higher GET and enhanced TT performance. Consequently, ingestion of DC reduced the oxygen cost of moderate intensity exercise and may be an effective ergogenic aid for short-duration moderate intensity exercise.

The purpose of the study was to measure the demands of off-road cycling via portable spirometry, leg-power output (PO), heart rate (HR) and blood lactate (BLa) concentration. Twenty-four male competitive cyclists (age: 29±7.2 yrs, height: 1.79 ± 0.05 m, body mass: 70.0 ± 4.9 kg, VO2peak: 64.9 ± 7.5 ml·kg(-1)·min(-1)) performed simulated mountain bike competitions (COMP) and laboratory tests (LabT). From LabT, we determined maximal workload and first and second ventilatory thresholds (VT1, VT2). A high-performance athlete (HPA) was used for comparison with three groups of subjects with different sport-specific performance levels. Load profiles of COMP were also investigated during uphill, flat and downhill cycling. During the COMP, athletes achieved a mean oxygen uptake (VO2COMP) of 57.0 ± 6.8 ml·kg(-1)·min(-1) vs. 71.1 ml·kg(-1)·min(-1) for the HPA. The POCOMP was 2.66±0.43 W·kg(-1) and 3.52 W·kg(-1) for the HPA. POCOMP, VO2COMP and HRCOMP were compared to corresponding variables at...

The early literature suggests that hypoventilation in infants with congenital central hypoventilation syndrome (CHS) is less severe during rapid eye movement (REM) than during non-REM (NREM) sleep. However, this supposition has not been rigorously tested, and subjects older than infancy have not been studied. Given the differences in anatomy, physiology, and REM sleep distribution between infants and older children, and the reduced number of limb movements during REM sleep, we hypothesized that older subjects with CHS would have more severe hypoventilation during REM than NREM sleep. Nine subjects with CHS, aged (mean ± SD) 13 ± 7 yr, were studied. Spontaneous ventilation was evaluated by briefly disconnecting the ventilator under controlled circumstances. Arousal was common, occurring in 46% of REM vs. 38% of NREM trials [not significant (NS)]. Central apnea occurred during 31% of REM and 54% of NREM trials (NS). Although minute ventilation declined precipitously during both REM an...

We report our experience with CT-guided percutaneous catheter drainage of loculated thoracic air collections in mechanically ventilated patients with acute lung injury or acute respiratory distress syndrome. MATERIALS AND METHODS. Nine critically ill patients had 17 air collections (I 3 pneumothoraces, three pneumatoceles, one tension pneumomediastinum) that either developed despite the presence of standard surgical chest tubes or were in loculated sites that were difficult to access. All nine patients were ventilated mechanically for a clinical diagnosis of acute respiratory distress syndrome. Catheter size ranged from 7-to 28-French. Response was measured by imaging follow-up, ventilatory parameters, and clinical outcome. RESULTS. On follow-up imaging studies, all 17 air collections were shown to have been evacuated successfully. Catheters remained in place for a mean of 1 1 days (range. 4-28 days).

OBJETIVO: Avaliar condicionamento físico e força muscular de crianças asmáticas antes e depois de quatro meses de participação num programa de exercícios físicos. MÉTODOS: Dois grupos de crianças com asma moderada e idade entre oito e onze anos foram formados. Ambos realizaram testes pré e pós-treinamento físico, duas vezes por semana, por quatro meses, em sessões de 90 minutos, com exercícios em solo e em água. Orientações sobre asma, seu controle e tratamento foram fornecidos a ambos os grupos. RESULTADOS: Na avaliação final, observou-se aumento das variáveis antropométricas em ambos os grupos. O grupo exercício apresentou melhora significativa na distância percorrida em nove minutos (inicial 1,333 + 0,03 km e final 1,440 + 0,03 km; p &lt; 0,05), número de flexões abdominais (inicial 24,3 + 1,4 abdominais e final 33,2 + 1,1 abdominais; p &lt; 0,05), pressão inspiratória máxima (inicial 73 + 5 cmH2O e final 103 + 5 cmH2O; p &lt; 0,05), pressão expiratória máxima (inicial 75 + 4 cmH...