Significant Increase In Respiratory Rate Research Articles

Respiratory Safety Pharmacological Testing with Single Intravenous Administration of Caffeine in Sprague-Dawley Rats.

As caffeine consumption continues to increase, both positive and negative effects are becoming evident. Caffeine directly affects the cardiovascular system, including heart function and rate. Thus, understanding the current respiratory safety pharmacological responses is of utmost importance. To elucidate the respiratory safety pharmacological characteristics of caffeine, male Sprague-Dawley rats, aged 6 weeks, were intravenously administered doses of 0, 2, 6, and 20 mg/kg of caffeine. Respiratory rate, tidal volume, and minute volume were subsequently measured. In this study, we observed a significant increase in respiratory rate and minute volume, but a remarkable reduction in tidal volume following the intravenous administration of caffeine at doses exceeding 6 mg/kg. These changes were evident within the timeframe of 0.25 to 1.5 h. The data we have collected can serve as valuable foundational scientific information for future research on caffeine, encompassing absorption, distribution, metabolism, excretion, and pharmacological core-battery experiments.

Effect of retropneumoperitoneum on cerebral and renal oxygen saturation during retroperitoneal robotic-assisted laparoscopic pyeloplasty (R-RALP) in a pediatric population: Preliminary results of a prospective observational study using a dedicated anesthetic protocol and Near-InfraRed Spectroscopy

BackgroundRetroperitoneal robotic-assisted laparoscopic pyeloplasty (R-RALP) for ureteropelvic junction obstruction (UPJO) has gained growing acceptance among pediatric urologists, and is increasingly performed as day-case surgery, involving smaller children and infants. However, retroperitoneal CO2 insufflation may cause hemodynamic derangements, respiratory changes, and hypercapnia, whose consequences are poorly investigated. We, therefore, decided to prospectively study its effect on regional tissue perfusion and oxygenation in a cohort of pediatric patients undergoing R-RALP, using a dedicated anesthetic protocol and cerebral and renal Near InfraRed Spectroscopy (NIRS). Material and methodsBetween January 2021 and September 2022, a cohort of 21 consecutive children [12 males (9 females), mean age of 7.1 ± 3.8 years and mean body weight of 25.7 ± 12.3 kg] underwent their first elective pyeloplasty for UPJO by R-RALP. The surgical procedure followed a previously described standardized technique and a dedicated anesthetic protocol. In conjunction with the minimal expected standard monitoring, cerebral and renal NIRS were added. Standard monitoring parameters and NIRS values were recorded at preset points throughout the procedures. ResultsStandard monitoring and NIRS measurements during R-RALP were not adversely affected by CO2 insufflation, pending a significant increase in respiratory rate, aimed to avoid hypercapnia, while keeping the ventilation pressure within the safety range, preventing lung injury. ConclusionsR-RALP, using a constant retroperitoneal CO2 insufflation pressure of 12 mmHg with a 5 L.min−1 flow, does not adversely affect respiratory and hemodynamics parameters, pending the implementation of a specifically designed anesthetic protocol aimed to prevent hypercapnia, the most threatening effect of retroperitoneal CO2 insufflation. Clinical Trial Registration NumberNCT03274050.

Comparison of Changes in Chest Wall Mechanics and Respiratory Timing Between Patient-Controlled Epidural Analgesia and Intravenous Patient-Controlled Analgesia After Laparoscopic Gastrectomy: A Randomized Controlled Trial.

Upper abdominal surgery is associated with postoperative diaphragmatic dysfunction. Whether patient-controlled epidural analgesia (PCEA) is superior to intravenous patient-controlled analgesia (IV-PCA) in preventing postoperative diaphragmatic dysfunction is still unclear in laparoscopic gastric surgery. Sixteen patients undergoing laparoscopic gastrectomy randomly received either PCEA or IV-PCA. The primary outcomes were the change in chest wall mechanics and respiratory timing, measured by respiratory inductive plethysmography(Respitrace; Ambulatory Monitoring Inc., Ardsley, New York, United States) before and after surgery, and analyzed by a data acquisition system (PowerLab; ADInstruments, Dunedin, New Zealand). Inspiratory time (Ti), expiratory time (Te), total respiratory cycle time (Ttot), proportion of inspiratory time over total respiratory cycle time (Ti/Ttot), respiratory rate (RR), and abdominal contribution to tidal volume (AB/VT [%]) were calculated from the stored data. AB/VT, relative volume contribution of diaphragm to tidal breathing, represents an index of diaphragmatic function.Because the diaphragm is the main contributor to tidal volume, decreases in AB/VT indicate diaphragm dysfunction. Changes in outcomes over time between the two groups were analyzed using a linear mixed model, and two-sided p values < 0.05 were considered statistically significant. The secondary outcomes were postoperative pain score(visual analog scale (VAS)), bowel function recovery, and hospital stay duration. Postoperative AB/VT in the IV-PCA group was significantly decreased compared to preoperative levels. AB/VT in the PCEA group was significantly higher than the IV-PCA group on postoperative day (POD) 1. Change in AB/VT over time between the PCEA group and the IV-PCA group differed significantly (p = 0.01). A decrease of AB/VT during POD 1 to 3 was observed in the IV-PCA group but not in the PCEA group. As for respiratory timing, there were significant increases in RR with a reduction of Te and Ttot compared to preoperative levels on POD 1 in the PCEA group. There were significant decreases in RR and Ti/Ttot with an increase of Te and Ttot compared to preoperative levels on POD 1 in the IV-PCA group. There was a significant difference in the change of the Ttot over time between the two groups (p = 0.046). There were no significant differences in the changes of Te, Ti/Ttot, Ti, and RR over time between the two groups. There was no significant difference in VAS over time at rest and mobilization, recovery of bowel function, and hospital stay between the two groups. Continuous ropivacaine infusion with PCEA partially attenuated diaphragmatic dysfunction after laparoscopic gastrectomy, while pain relief by continuous intravenous administration of fentanyl could not attenuate diaphragmatic dysfunction. This suggests that PCEA might ameliorate postoperative diaphragmatic dysfunction after laparoscopic gastrectomy.

Immediate Effectiveness of Chest Proprioceptive Neuromuscular Facilitation (PNF) Technique on Hemodynamic Status in COVID-19 Patients: An Original Research.

IntroductionCOVID-19 is an infectious illness that first appeared in Wuhan, China in December 2019, and subsequently spread over the entire world. Those who were affected suffered from fever, cough, weakness, and breathlessness, along with the probability of developing pneumonia which sometimes leads to respiratory failure. The older population with co-morbidities was at higher risk.MethodsIn this experimental study, 59 subjects with COVID-19 were included according to pre-decided inclusion and exclusion criteria. Pre-vitals before the treatment were noted such as heart rate, respiratory rate, and oxygen saturation (SPO2), and then the chest proprioceptive neuromuscular facilitation (PNF) technique was given as a treatment regime, and its immediate effect was calculated. Post-vitals were noted immediately after the treatment session. The statistical analysis was made using the student's paired t-test.ResultsWe found a mean difference of 9.45±5.27 in heart rate before and after the intervention provided which is suggestive of a statistically significant increase within normal limits. Also, the mean value of respiratory rate immediately after the intervention was shown as 22.91 and pre-intervention was 19.18 with a mean difference of 2.93±3.95, showing a statistically significant increase in respiratory rate. Additionally, the mean value of SPO2 immediately after the intervention was shown as 92.76 and pre-intervention was 94.64 and had a mean difference of 1.88±1.67 suggestive of high improvement in oxygen saturation immediately after the intervention.ConclusionThe present study concludes from the available statistical analysis that chest PNF techniques such as intercostal stretch and anterior basal stretch lift have an immediate impact on improvement in oxygen saturation in COVID-19 patients and can be incorporated as an inpatient treatment regime in the rehabilitation protocol.

The Role of Carotid Body Chemoreceptor Afferents in Mediating Abnormal Ventilation in Acute Lung Injury

Background‐Acute lung injury (ALI) induces inflammation that disrupts the normal alveolar‐capillary endothelial barrier which impairs gas exchange to induce hypoxemia that reflexively increases respiration. Increased respiratory rate (RR) usually develops within a few hours to a few days after ALI. This disorder of acute respiratory failure affects approximately 200,000 new cases each year in the US alone and has high morbidity and mortality. The neural mechanisms underlying the respiratory dysfunction after ALI are not fully understood. The purpose of this study involved investigating the role of carotid body chemoreceptor afferents in mediating abnormal ventilation in ALI.Methods and Results‐ALI was induced in male SD rats (200‐250g) using a single intra‐tracheal injection of bleomycin (Bleo) (day 0) and respiratory variables‐ RR, TV (Tidal Volume), and MV (Minute Ventilation) in response to 10% hypoxia (10% O2, 0% CO2) and 5% hypercapnia (21% O2, 5% CO2) were measured weekly from W1‐W4 using whole‐ body plethysmography (WBP). MV at 21% O2 increased from baseline (W0) to W1 and W2 in bleo treated rats (p≤0.01 compared to saline treated sham rats). Changes in MV were due to a significant increase in RR while TV showed no changes. Chemoreflex was assessed by measuring the absolute difference between 21% O2 and hypoxia (10% O2, 0% CO2) &amp; hypercapnia (21% O2, 5% CO2). Chemoreflex activation is a fundamental protective reflex that maintains oxygen homeostasis. Our data indicated a blunted chemoreflex at W1 and a sensitized chemoreflex in W3‐W4 during hypoxia and hypercapnia. We hypothesized that the blunted chemoreflex in W1 could be due to maximal pre‐activation of chemoreceptors, called the ‘ceiling effect’. To test this possibility, 90% hyperoxia (90% O2, 0% CO2) was given to bleo treated rats to inhibit the chemoreflex and our results showed no changes in RR, suggesting absence of the tonic activity at W1 post‐ALI.Conclusions‐These data suggest that chemoreflex activation in response to hypoxia and hypercapnia is blunted at acute stage of lung injury but became sensitized at the recovery stage.

Abstract No.: ABS3339: Effects of volume controlled and pressure controlled volume guaranteed modes of ventilation on respiratory dynamics during laparoscopic surgery in children: A prospective observational study

Background & Aims:The aim of the study was to compare the effects of Volume controlled ventilation (VCV) and Pressure controlled volume guaranteed ventilation (PCV-VG), which delivers the target tidal volume at the lowest possible pressure, on respiratory dynamics during paediatric laparoscopic surgery.Methods:In this prospective observational study, 52 patients of 0-15 years were included; (n= 26) each for VCV and PCV-VG.fraction of inspired oxygen(FiO2)50%, tidal volume 6-10 ml/kg, age appropriate respiratory rate (RR) to maintain end-tidal carbon dioxide (EtCO2) between 35-40 mm Hg, PEEP 4 cm and P-limit 10 cm above the initial peak pressure were set. Peak inspiratory pressure (PIP), Plateau pressure (PlatP), expiredtidal volume (VTe)/kg, compliance (Compl), airway resistance (R), ETCO2 and saturation of O2 (SaO2)were noted after intubation, creation of pneumoperitoneum, changing position, desufflation and change of position to supine.Results:Demographic criteria, haemodynamic parameters, set and measured respiratory parameters at all time points were similar inboth groups. Trendelenburg position was required in 11 children in VCV and 13 in PCV-VG group. Following this, there was similar increase in PIP, PlatP, R and decrease in CompL in both groups. However, significant increase in RR was required inVCV group (percentage change in RR- —VCV: 3.5±5.01, PCV-VG : 0±00, p=0.039) to maintain normal ETCO2.Conclusion:Either VCV or PCV-VG mode of ventilation, can be used during paediatric laparoscopic surgery in supine position.However, with Trendelenburg position, PCV-VG provides a marginal advantage over VCV mode of ventilation.

Impact of therapeutic thoracentesis and pleural pressure changes on breathing pattern, dyspnea, lung function, and arterial blood gases.

Therapeutic thoracentesis is highly effective in providing symptomatic improvement in patients with large volume pleural effusion (PE). However, some physiological effects of pleural fluid (PF) withdrawal are still not fully elucidated. The study aimed to evaluate alterations in the breathing pattern, pulmonary function, and arterial blood gases (ABG) in relation to both withdrawn PF volume and pleural pressure (Ppl) changes in patients undergoing therapeutic thoracentesis. This prospective, observational, cross‑sectional study included 37 patients with large volume PE. Respiratory rate (RR), dyspnea, pulmonary function, and ABG were assessed before the thoracentesis, at the termination of the PF withdrawal and 1, 3, and 24 hours after the procedure. The volume of PF drained, Ppl, and tidal volume (TV) were monitored during the thoracentesis. Thoracentesis resulted in a transient but significant increase in RR directly after the procedure, and a transient decrease, followed by subsequent increase in TV. There was a significant and constant increase in forced vital capacity up to 24 hours after thoracentesis (P = 0.001). Oxygen partial pressure (PaO2) significantly improved directly after PF withdrawal (P = 0.01) and returned to baseline values after 24 hours. Thoracentesis was invariably associated with a significant increase in the amplitude of Ppl (Ppl_ampl) changes during the respiratory cycle (P <0.001). Therapeutic thoracentesis results in a modest improvement in pulmonary function, tran-sient increase in PaO2 and increase in Ppl_ampl. The improvement in pulmonary function and ABG is closely related to the volume of PF drained and pleural elastance. The increase in Ppl_ampl probably represents a more efficient work of the respiratory muscles.

Abstract 12374: Physiologic Changes of COVID-19 Infection Detected by Cardiac Implantable Electronic Device Data

Background: The trajectory of cardiac physiology throughout a COVID-19 infection remains poorly described. This study aimed to characterize physiologic changes associated with acute COVID-19 infection among patients with cardiac implantable electronic devices (CIEDs). Methods: The study population included 286 patients with a Boston Scientific CIED across a large health system. CIED sensor data from March 2020 - February 2021 were linked to clinical data from electronic health records. Three cohorts were created: COVID-positive (n=20), COVID-negative (n=166), and an untested control (n=100) to account for testing bias as institutional protocols only allowed symptomatic patients to be tested in the early months of the study. The magnitude of sensor changes from baseline (30-60 days before a COVID-19 test) to event (15-day window around a test) was compared between cohorts using one-way ANOVA. A date during the study window was randomly selected to serve as the event for control cases. Results: Comparing COVID-positive vs. COVID-negative vs. control, there was a greater change from baseline to event in respiratory rate (15% vs. 2% vs. 0.6% [p&lt;0.0001]), activity (-44% vs. -12% vs. -6% [p&lt;0.0001]), temperature (1% vs. 0.1% vs. -0.3% [p&lt;0.0001]), and HeartLogic Index, a composite index using multiple sensors (227% vs. -11% vs. 2% [p=0.004]). Average sensor changes show prominent differences surrounding a COVID-19 test for COVID-positive compared to COVID-negative and control cases ( Figure ). Conclusions: Physiologic changes associated with COVID-19 infection are detectable using CIEDs. COVID-positive patients have significant increases in respiratory rate, temperature and HeartLogic index and significant decreases in activity compared to COVID-negative and untested patients. Future studies in a larger population will help characterize the utility of CIEDs in infection surveillance and physiologic worsening that should prompt medical attention.

Spacecraft launch and re-entry: Effects of simulated +Gx acceleration on cardiorespiratory parameters

Introduction: In the spaceflight, during launch and re-entry, the crew is exposed to acceleration ranging from +4Gx to +8Gx in nominal conditions. This study was conducted to assess the changes in cardiorespiratory parameters, namely, heart rate (HR), electrocardiogram (ECG), respiratory rate (RR), and SpO2 on exposure to simulated +Gx acceleration. Material and Methods: Fifteen randomly selected healthy male volunteers participated in the study. They were exposed to a simulated acceleration profile consisting of two peaks in the high-performance human centrifuge; first peak of +4Gx for 30 s and second peak of+8Gx for 30 s. The cardiorespiratory parameters were monitored and recorded during the acceleration exposure. The data were compiled and analyzed using one-way repeated measures ANOVA. Results: Significant increase in HR was observed on exposure to +4Gx (110.4 ± 16.7 bpm; P &lt; 0.001) in comparison to the baseline value (80.5 ± 7.5 bpm). However, the changes in the HR at +8Gx were not significant in comparison to baseline as well as +4Gx values. On the other hand, RR indicated a significant increase on exposure to +8Gx (25.2 ± 5.8 breaths/min) in comparison to the baseline (15.1 ± 1.6 breaths/min; P = 0.001) and +4Gx (19.0 ± 6.1 breaths/min; P = 0.009) values. SpO2 showed a significant reduction at +8Gx (94.2 ± 3.8%) in comparison to baseline (98.9 ± 0.3%; P = 0.004) and +4Gx (96.9 ± 1.5%; P = 0.003). ECG did not show any evidence of arrhythmia during the exposure to +Gx acceleration. Conclusion: The insignificant changes in the HR at peak of +8Gx indicate less pronounced effects on the smaller hydrostatic gradient in +Gx acceleration unlike +Gz acceleration. However, the findings of the study point towards a significant increase in respiratory rate and reduction in SpO2 at +8Gx.

Good news on masks

Although guidance is changing rapidly, it appears that the use of face masks will be an important component for the safe return of some children to school. Unfortunately, this guidance has been undermined by largely unfounded concerns about mask safety in children. An article in the current volume of The Journal addresses one aspect of mask safety in children, the use of N95s. Because current guidance calls for the use of cloth or surgical masks in most settings, the findings of the study by Lubrano et al should reassure us about the use of these more specialized masks for exceptional circumstances. Studying children wearing these masks (both with and without exhalation valves), the authors observed no changes in pulse rate or oxygen saturation. Although there were some marginally significant increases in respiratory rate and end tidal CO2 in children during mask wearing, neither of these were to levels of clinical importance. These findings are consistent with similar studies in adults. As the authors point out, no concerns about respiratory function have been raised with the use of less-restrictive masks (eg, cloth) in children. Discussions about the use of masks in children in school will likely continue for some time. Concern about safety probably does not need to be a part of these discussions. Article page 143 ▸ Effects of N95 Mask Use on Pulmonary Function in ChildrenThe Journal of PediatricsVol. 237PreviewTo assess whether use of an N95 mask by children is associated with episodes of desaturation or respiratory distress. Full-Text PDF

Physiological, oxidative and metabolic responses of lactating water buffaloes to tropical climate of South China.

BackgroundHeat stress in tropics is generally associated with significant economic losses resulting from reduced performance, morbidity, and mortality of livestock. To avoid serious consequences of heat stress, it is imperative to better understand the physiological responses and biochemical changes under the state of altered body homeostasis during different seasons of the year.ObjectivesThis study aimed to evaluate the seasonal dynamics of physiological, oxidative and metabolic responses of lactating Nili‐Ravi buffaloes to the tropical climate of South China.MethodsPhysiological responses including rectal temperature (RT), body surface temperature (BST) and respiratory rate (RR) along with serum biochemical and antioxidant parameters of 20 lactating Nili‐Ravi buffaloes were evaluated during different seasons of the year.ResultsHigher temperature‐humidity Index (THI) during the summer season (>80) resulted in a significant increases in RR and BST as compared to the winter season. Higher oxidative stress was observed in the summer season as revealed by significantly higher MDA while lower serum antioxidant enzyme (TAC, GSH‐Px, SOD and CAT) contents. Moreover, serum cortisol was also significantly higher in summer and autumn. The levels of growth hormone and ACTH were also significantly (P < 0.05) lower in summer and autumn as compared to other seasons. The negative association of THI with physiological and antioxidant parameters was observed while it was positively associated with serum MDA and cortisol levels.ConclusionsOur study revealed moderate heat stress in lactating buffaloes in the summer season which calls for attention to avoid economic losses and animal welfare issues.

Effects of N95 Mask Use on Pulmonary Function in Children

To assess whether use of an N95 mask by children is associated with episodes of desaturation or respiratory distress. Twenty-two healthy children were assigned at random to 1 of 2 groups: one group wearing N95 masks without an exhalation valve and the other group wearing N95 masks with an exhalation valve. We tracked changes in partial pressure of end-tidal carbon dioxide (PETCO2), oxygen saturation, pulse rate, and respiratory rate over 72minutes of mask use. All subjects were monitored every 15minutes, the first 30minutes while not wearing a mask and the next 30minutes while wearing a mask. They then performed a 12-minute walking test. The children did not experience a statistically significant change in oxygen saturation or pulse rate during the study. There were significant increases in respiratory rate and PETCO2 in the children wearing an N95 mask without an exhalation valve, whereas these increases were seen in the children wearing a mask with an exhalation valve only after the walking test. The use of an N95 mask could potentially cause breathing difficulties in children if the mask does not have an exhalation valve, particularly during a physical activity. We believe that wearing a surgical mask may be more appropriate for children.

Novel Mechanism of Neural Control of Breathing in Acute Lung Injury (ALI)

Increased respiratory rate (RR) usually develops within a few hours to a few days after ALI. However, the neural mechanisms underlying the breathing dysfunction after ALI are not fully understood. The purpose involved investigating the role of chemoreceptor afferents and pulmonary spinal afferents in the control of breathing in ALI. ALI was induced in male SD rats (200-250g) using intra-tracheal injections of bleomycin (Bleo) (day 0) and measured RR, TV (Tidal Volume), and MV (Minute Ventilation) weekly from W1-W4 using whole body plethysmography (WBP). Chemoreflex was assessed by measuring the absolute difference between 21% O2 and hypoxia (10% O2) & hypercapnia (5% CO2 and 7% CO2). MV at 21% O2 increased from baseline to W1 and W2. Changes in MV were due to significant increase in RR while TV showed no changes. Blunted chemoreflex was observed at W1 and W2 during hypoxia and hypercapnia which could be due to maximal pre-activation of chemoreceptors, called ceiling effect. Chemoreflex was inhibited in bleo-rats through 90% O2 (hyperoxia) which showed no changes in RR, suggesting absence of tonic activity. Other experiments included bleomycin on day 0, ablation of TRPV1-positive lung spinal afferents by bilaterally injecting 5μl of RTX (50 μg/ml) into the stellate ganglion (day 3) and measuring lung parameters (day 7). RTX ablation of pulmonary spinal afferents caused a significant reduction in RR in bleo-rats at W1. These data suggest that chemoreflex activation in response to hypoxia and hypercapnia is blunted whereas, pulmonary spinal afferent activation may play a major role in the increased RR in ALI.

Результати морфологічного дослідження крові корів за теплового стресу залежно від стадій температурно-вологісного індексу

The results of morphological studies of the blood of cows under heat stress indicate that the temperature - humidity index (THI) of animals in comfortable conditions (THI - 68-71) the number of erythrocytes is 5.78 ± 0.13 T / l, the hematocrit - 24.98 ± 1.02%, hemoglobin content - 89.96 ± 2.63 g / l, MCV - 39.76 ± 2.31 fl; MCH - 15.56 ± 1.32 pg; MCHC - 39.14 ± 1.95 g / dl. The total number of leukocytes in the blood of cows is 7.17 ± 0.54 G / l. The relative content (leukogram) and the absolute number of certain types of leukocytes in the blood of cows has no abnormalities. This suggests that the morphological parameters of the blood of cows in the comfortable conditions of THI meet the normative values for cattle and, in particular, Holstein breed. Under moderate heat stress (THI -72-78), in the blood of cows, along with a significant increase in respiratory rate and heart rate, there is a tendency to increase the number of erythrocytes to 5.82 ± 0.69 T / l, there is a significant increase in hematocrit and MCV by 20 and 47%, and a significant decrease in hemoglobin, MCH and MCHC - by 32, 35 and 55%, respectively, relative to control. However, in the blood of cows there is a tendency to decrease the number of leukocytes, with the simultaneous appearance of metamyelocytes, an increase in the number of eosinophils and rod neutrophils, and a significant decrease in the number of lymphocytes by 27% compared to control. Under severe heat stress (THI - 80-90), when the pulse in cows fluctuates between 88-140 beats per minute, and the respiratory rate is 82.0 ± 3.76 respiratory movements, the number of erythrocytes in the blood of cows tends to decrease and is 5.01 ± 0.91 T / l. The hematocrit value is 21% significantly (p≤0.05) less than in cows under moderate heat stress, and is almost the same as in cows under comfortable conditions. The content of hemoglobin in the blood of cows in this period is significantly lower by 28% (p≤0.05) compared to that in cows under comfortable conditions with a slight tendency to increase compared to this figure in cows under moderate heat stress. Color indices indicate that in the blood of cows under severe heat stress there is a large number of young erythrocytes-macrocytes (MCV - 53.69 ± 3.22 fl), which are poor in hemoglobin (MSN - 12.95 ± 3.48 pg) and impaired hemoglobin formation (MCHC - 24.11 ± 2.23 g / dl). The total number of leukocytes in the blood of cows under severe heat stress is 10.80 ± 1.55 G / l, which is 78% (P≤0.01) more than under moderate heat stress and increases due to the appearance of young and an increase of almost in twice rod-shaped and segment-nuclear neutrophils and eosinophils with a simultaneous decrease in the percentage of lymphocytes.

Dynamic hyperinflation induced by the 6-minute pegboard and ring test in hospitalized patients with exacerbated COPD.

The six-minute pegboard and ring test (6-PBRT) has been used to evaluate functional capacity of the upper limbs in stable chronic obstructive pulmonary disease (COPD) patients. To the best of our knowledge, no studies have evaluated dynamic hyperinflation (DH) during exercise with upper limbs in the hospital setting. The aim of this study was to evaluate physiological responses and DH induced by 6-PBRT in hospitalized patients with acute exacerbation of COPD (AECOPD). A cross-sectional study was conducted in a tertiary hospital enrolling patients who were hospitalized due to AECOPD. All included participants underwent an evaluation of lung function and 6-PBRT when they reached minimum clinical criteria. Ventilatory and hemodynamics parameters were monitored during 6-PBRT and until 6 minutes of rest after the test. Symptoms of dyspnea and upper limb fatigue were also measured. Eighteen patients (71.3±5.1 years) with a mean FEV1 of 43.2±18.3% were included in the study (11 females). Prevalence of DH after 6-PBRT was 50% (considering the drop of 150 ml or 10% of inspiratory capacity, immediately after the end of the test). There was a significant increase in respiratory rate, minute volume, dyspnea, and upper limb fatigue after the end of 6-PBRT (p<0.05). Dyspnea recovered more precociously than the perception of fatigue, being reestablished within four minutes of rest. An increase in heart rate, systolic and diastolic blood pressures was also induced by 6-PBRT (p<0.05), requiring 6 minutes of recovery to return to baseline. No adverse events were observed during 6-PBRT. We concluded that 6-PBRT induces physiological changes during its execution, at safe levels, requiring a maximum of 6 minutes for recovery. Finally, the test proved to be safe and applicable for patients hospitalized due to AECOPD.

Seasonal Dynamics of Physiological, Oxidative and Metabolic Responses in Non-lactating Nili-Ravi Buffaloes Under Hot and Humid Climate.

Hot and humid weather exposes animals to high temperature and relative humidity that ultimately reduce their ability to disperse body heat. To avoid serious consequences of heat stress, it is imperative to understand animal physiological responses and biochemical changes during a state of altered body homeostasis across different seasons of the year. This study evaluated seasonal dynamics of physiological, oxidative, and metabolic responses of Nili-Ravi buffaloes to hot and humid climate. Twenty non-lactating multiparous buffaloes were enrolled for this 1-year study. Meteorological data were recorded twice daily to calculate temperature humidity index (THI). Physiological parameters including rectal temperature (RT), body surface temperature (BST), and respiratory rate (RR) were measured weekly. Blood samples were collected once in each season (spring, summer, autumn, and winter) to analyze biochemical and antioxidant parameters. We also measured activities of liver enzymes including alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The results revealed a significantly higher THI value (82) during summer which resulted in a significant increase in RR and BST as compared to winter. Higher oxidative stress was observed in summer owing to significantly higher malondialdehyde (MDA) content and lower levels of serum antioxidant enzymes (GPx, SOD, and CAT) as compared to other seasons. Moreover, serum cortisol was also significantly higher while adrenocorticotropic hormone (ACTH), Triiodothyronine (T3), insulin, and growth hormone contents were significantly lower in summer. Contrarily, plasma thyroxin (T4) level was higher in summer. THI showed a positive correlation with physiological responses but a negative correlation with antioxidant parameters. Our study provides practical insights on the adaptive physiology of buffaloes and has several implications regarding the alleviation of heat stress in buffaloes to enhance the efficiency of production and reproduction under tropical climate. Our study suggests the use of appropriate cooling strategies to effectively manage the non-lactating buffaloes to avoid performance losses and animal welfare issues in summer season.

High-Flow Nasal Oxygen in Coronavirus Disease 2019 Patients With Acute Hypoxemic Respiratory Failure: A Multicenter, Retrospective Cohort Study*

An ongoing outbreak of coronavirus disease 2019 is spreading globally. Acute hypoxemic respiratory failure is the most common complication of coronavirus disease 2019. However, the clinical effectiveness of early high-flow nasal oxygen treatment in patients with coronavirus disease 2019 with acute hypoxemic respiratory failure has not been explored. This study aimed to analyze the effectiveness of high-flow nasal oxygen treatment and to identify the variables predicting high-flow nasal oxygen treatment failure in coronavirus disease 2019 patients with acute hypoxemic respiratory failure. A multicenter, retrospective cohort study. Three tertiary hospitals in Wuhan, China. Forty-three confirmed coronavirus disease 2019 adult patients with acute hypoxemic respiratory failure treated with high-flow nasal oxygen. None. Mean age of the enrolled patients was 63.0 ± 9.7 years; female patients accounted for 41.9%. High-flow nasal oxygen failure (defined as upgrading respiratory support to positive pressure ventilation or death) was observed in 20 patients (46.5%), of which 13 (30.2%) required endotracheal intubation. Patients with high-flow nasal oxygen success had a higher median oxygen saturation (96.0% vs 93.0%; p < 0.001) at admission than those with high-flow nasal oxygen failure. High-flow nasal oxygen failure was more likely in patients who were older (p = 0.030) and male (p = 0.037), had a significant increase in respiratory rate and a significant decrease in the ratio of oxygen saturation/FIO2 to respiratory rate index within 3 days of high-flow nasal oxygen treatment. In a multivariate logistic regression analysis model, male and lower oxygen saturation at admission remained independent predictors of high-flow nasal oxygen failure. The hospital mortality rate of the cohort was 32.5%; however, the hospital mortality rate in patients with high-flow nasal oxygen failure was 65%. High-flow nasal oxygen may be effective for treating coronavirus disease 2019 patients with mild to moderate acute hypoxemic respiratory failure. However, high-flow nasal oxygen failure was associated with a poor prognosis. Male and lower oxygenation at admission were the two strong predictors of high-flow nasal oxygen failure.

ADAPTIVE CAPACITY OF STUD RAMS OF ASKANIAN MEAT AND WOOL BREED AND PARAMETERS OF SELECTION OF ZAKARPATTJA-TYPE PRECOCE BREED EWES FOR INTER-BREEDING

The rams of the Askanian meat-wool breed, grown and kept in the conditions of the steppe zone of the south of Ukraine, were investigated for their adaptive capacity and adaptation to the conditions of the lowland regions of Zakarpattja.&#x0D; It was found that the physiological response of the rams to the maximum air temperature was characterized by a slight increase in body temperature and pulse, and a significant increase in respiratory rate per 1 minute. The good adaptive properties of the Askanian meat and wool breed rams are indicated by the high breeding capacity of ewes, at 97%, in both farms. The ewes of the breed prekos with a live weight of 55.9–58.9 kg were involved in the breeding process, and the Askanian rams with a live weight of 93.3–95.1 kg. It was studied the influence of crossbred crossing of crossbred Askanian sheep of meat and wool breed on the development of productive and reproductive features of Zakarpattja sheep ewes of the breed prekos with the purpose of obtaining mixed breeds with improved economic performance. It is proven by theory and practice that one of the main criteria for the rational management of sheep breeding in modern conditions is the study of individual features of growth and development of young sheep. In a market economy, increasing the meat productivity of sheep is an important factor that determines the level of economic efficiency of the industry. Obtained progeny at the age of 4–8 months had a higher intensity of growth. Thus, the average daily weight gain of lambs in the control group was 234 g, and experimental — 265 g, which is 11.3% more than in the control. The average daily weight gain of the bright control group was 205 g, and the experimental one — 244 g, which is 11.9% more than in the control group. At the age of 8 months, the fat mass of slaughtered animals ranged from 32–36 kg and the carcass weight was 15–18 kg with good fat irrigation.&#x0D; The classification of sheep carcasses by fat irrigation according to the EUROP system corresponded to the average level of coverage of carcasses with fat, that is, the whole carcass was covered with a thin layer of fat, at the base of the tail — small accumulations of fat, the kidneys partially or completely covered with a thin layer of fat, with a slight fatty water between visible intercostal muscles .The balanced feeding of experimental animals had a positive effect on the increase in live birth weight and their viability. The minimum selection parameters of breeding sheep ewes, which are involved in the breeding process, are also set for obtaining animals with high multi-farrowing and combined productivity.

Diaphragm-triggered non-invasive respiratory support in preterm infants.

Diaphragm-triggered non-invasive respiratory support, commonly referred to as NIV-NAVA (non-invasive neurally adjusted ventilatory assist), uses the electrical activity of the crural diaphragm to trigger the start and end of a breath. It provides variable inspiratory pressure that is proportional to an infant's changing inspiratory effort. NIV-NAVA has the potential to provide effective, non-invasive, synchronised, multilevel support and may reduce the need for invasive ventilation; however, its effects on short- and long-term outcomes, especially in the preterm infant, are unclear. To assess the effectiveness and safety of diaphragm-triggered non-invasive respiratory support in preterm infants (< 37 weeks' gestation) when compared to other non-invasive modes of respiratory support (nasal intermittent positive pressure ventilation (NIPPV); nasal continuous positive airway pressure (nCPAP); high-flow nasal cannulae (HFNC)), and to assess preterm infants with birth weight less than 1000 grams or less than 28 weeks' corrected gestation at the time of intervention as a sub-group. We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2019, Issue 5), MEDLINE via PubMed (1946 to 10 May 2019), Embase (1947 to 10 May 2019), and CINAHL (1982 to 10 May 2019). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-randomised trials. Randomised and quasi-randomised controlled trials that compared diaphragm-triggered non-invasive versus other non-invasive respiratory support in preterm infants. Two review authors independently selected trials, assessed trial quality and extracted data from included studies. We performed fixed-effect analyses and expressed treatment effects as mean difference (MD), risk ratio (RR), and risk difference (RD) with 95% confidence intervals (CIs). We used the generic inverse variance method to analyse specific outcomes for cross-over trials. We used the GRADE approach to assess the certainty of evidence. There were two small randomised controlled trials including a total of 23 infants eligible for inclusion in the review. Only one trial involving 16 infants included in the analysis reported on either of the primary outcomes of the review. This found no difference in failure of modality between NIV-NAVA and NIPPV (RR 0.33, 95% CI 0.02 to 7.14; RD -0.13, 95% CI -0.41 to 0.16; 1 study, 16 infants; heterogeneity not applicable). Both trials reported on secondary outcomes of the review, specific for cross-over trials (total 22 infants; 1 excluded due to failure of initial modality). One study involving seven infants reported a significant reduction in maximum FiO₂ with NIV-NAVA compared to NIPPV (MD -4.29, 95% CI -5.47 to -3.11; heterogeneity not applicable). There was no difference in maximum electric activity of the diaphragm (Edi) signal between modalities (MD -1.75, 95% CI -3.75 to 0.26; I² = 0%) and a significant increase in respiratory rate with NIV-NAVA compared to NIPPV (MD 7.22, 95% CI 0.21 to 14.22; I² = 72%) on a meta-analysis of two studies involving a total of 22 infants. The included studies did not report on other outcomes of interest. Due to limited data and very low certainty evidence, we were unable to determine if diaphragm-triggered non-invasive respiratory support is effective or safe in preventing respiratory failure in preterm infants. Large, adequately powered randomised controlled trials are needed to determine if diaphragm-triggered non-invasive respiratory support in preterm infants is effective or safe.

ACE overexpression in myeloid cells increases oxidative metabolism and cellular ATP

ACE overexpression in myeloid cells increases oxidative metabolism and cellular ATP