A pilot study using the LASCA technique to analyze stress using heart rate variability.

In the quest to uncover biological cues that help explain organic changes brought on by an external stimulus, like stress, new technologies have become necessary. The Laser Speckle Contrast Analysis (LASCA) approach is one of these technologies that may be used to analyze biological data, including respiratory rate (RR) intervals, and then use the results to determine heart rate variability (HRV Thus, to evaluate the stress brought on by physical activity, this study used the LASCA approach. A stress induction procedure involving physical exertion was employed, and the results were compared to other established techniques (cortisol analysis and ECG signal) to verify the LASCA methodology as a tool for measuring HRV and stress. The study sample comprised 27 willing participants. The technique involving LASCA allowed for the non-invasive (non-contact) acquisition of HRV and the study of stress. Furthermore, it made it possible to gather pertinent data, such as recognizing modifications to the thermoregulation, peripheral vasomotor tonus, and renin-angiotensin-aldosterone systems that were brought on by elevated stress and, as a result, variations in HRV readings.

Thermal Comfort of Nelore Cattle (Bos indicus) Managed in Silvopastoral and Traditional Systems Associated with Rumination in a Humid Tropical Environment in the Eastern Amazon, Brazil.

The objective of this study was to evaluate the thermal comfort of Nelore cattle (Bos indicus) managed in silvopastoral and traditional systems associated with rumination behavior in a humid tropical environment in the Eastern Amazon, Brazil. The study was carried out on a rural property in Mojuí dos Campos, Pará, Brazil, during the transition period of the year, from June to July 2023. Over these two months, six consecutive data collection days were held. We selected 20 clinically healthy non-castrated male Nelore cattle, aged between 18 and 20 months, with an average weight of 250 kg and body condition score of 3.5 (1-5). These animals were randomly divided into two groups: traditional system (TS) and silvopastoral system (SS). The physiological variables evaluated included RR, RT and BST. The variables were analyzed using the linear mixed model. For agrometeorological variables, higher values were observed between 10:00 a.m. (33 °C) and 6:00 p.m. (30 °C), with the highest temperature observed at 4:00 p.m. (40 °C). The RR showed interactions (p = 0.0214) between systems and times; in general, higher RR were obtained in the Traditional. The animals' RT showed no significant difference (p < 0.05) between the production systems, but there was a statistically significant difference in relation to the time of collection (p < 0.0001). In the BGHI, it was possible to observe that there was mild stress in the period from 22:00 at night to 6:00 in the morning and moderate stress in the period of greatest increase in temperature, from 10:00 in the morning to 18:00 at night. BST showed no statistical difference between the regions studied or between the SP (35.6 °C) and TS (36.25 °C) systems. RT in the TS showed a positive correlation with AT (r = 0.31507; p = 0.0477). RT in the SP showed a positive correlation with THI (r = 35583; p = 0.0242). On the other hand, RT in the SP (r = 0.42873; p = 0.0058) and ST (r = 0.51015; p = 0.0008) showed a positive correlation with BGHI. RR in the TS showed a positive correlation with BGHI (r = 0.44908; p = 0.0037). The greatest amounts of rumination were carried out by animals in the SP system, generally ruminating lying down (p < 0.05). With regard to rumination behavior in the morning and afternoon, there were higher numbers of WS and LD in the TS (p > 0.05). Most of the time, the cattle were LD during the morning and afternoon shifts, and at night and dawn they were WS in the TS. Therefore, the SP offers more thermal comfort advantages compared to the TS system.

Association between early manifestations of infection or sepsis and prognosis in a high complexity hospital in the city of Medellín.

OBJECTIVE: To identify the first symptoms and signs of patients with suspected infection or sepsis and their association with the composite outcome of admission to the Intensive Care Unit (ICU) or mortality. DESIGN: Prospective cohort study between June 2019 and March 2020. SETTING: Hospital Universitario San Vicente Fundación, Colombia. PATIENTS: Over 18 years of age with suspicion or confirmation of sepsis, which required hospitalization. INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: Symptoms and signs associated with infection, with their time of evolution, specified in the study. RESULTS: From 1005 eligible patients, 261 were included. After multivariable adjustment with a logistic regression model, the main factors for ICU admission or mortality were heart rate (OR 1.04 with 95% CI 1.04-3.7), respiratory rate (OR 1.19 with 95% CI 1.0-1.4) and capillary refill time (OR 3.4 with 95% CI 1.9-6.1). CONCLUSIONS: Heart rate, respiratory rate, and capillary refill may behave as early predictors of ICU admission and mortality in cases of sepsis.

Strategies to alleviate heat stress on performance and physiological parameters in feedlot-finished cattle under heat stress conditions. A systematic review-meta-analysis.

Strategies to alleviate heat stress on live performance - dry matter intake (DMI), average daily gain (ADG), and feed conversion efficiency (FCE) - and on physiological parameters - respiratory rate (RR) and panting score (PS) - of feedlot-finished cattle were evaluated by systematic review-meta-analysis. Using the PICO framework were identified 3813 records, with 31 publications and 6729 cattle being considered in the meta-analysis (MA). The comparison most reported was sun vs. shade (n = 24 publications), followed by shade vs. shade (area per animal and effectivity in reduce solar load) (n = 7 publications) and sun vs. sprinkling (n = 4 publications). Cattle with access to shade with total reduction in solar load improved ADG (p = 0.008) and FCE (p = 0.024), and reduced RR (p < 0.001) compared to unshaded animals. Cattle with access to shade with a height between 3 and 4 m increased ADG (p < 0.001), tended to improve FCE (p = 0.054), and reduced RR (p < 0.001) compared to unshaded animals. An area of shade from 2 to 4 m2/animal increased ADG (p = 0.002), and higher than 4 m2/animal reduced RR (p < 0.001) compared to unshaded animals. Animals that received sprinkling volume below 1 L/animal/min improved ADG (p = 0.008) compared to unshaded animals. Cattle with access to shade with a high area per animal improved DMI (p = 0.023) and ADG (p < 0.001) compared to animals with a low area. In univariate meta-regression, it was observed that the variables significantly (P < 0.05) influencing DMI were THI category; influencing ADG were cattle gender, THI category, and coat color; influencing FCE were cattle age and hemisphere; and influencing RR were country, THI category and climate. Performance and physiological parameters of feedlot-finished cattle under heat stress depend on animal and environmental characteristics.

The use of successive systolic differences in photoplethysmographic (PPG) signals for respiratory rate estimation.

Most PPG-based methods for extracting the respiratory rate (RR) rely on changes in the PPG signal's amplitude, baseline, or frequency. However, several other parameters may provide more valuable information for accurate RR computation. In this study, we explored the capabilities of the respiratory-induced variations in successive systolic differences (RISSDV) of PPG signals to estimate RR. We partitioned fifty-three publicly available recordings into eight 1-min segments and identified peaks and troughs of the PPG signals to quantify respiratory-induced variations in amplitude (RIAV), baseline (RIIV), frequency (RIFV), and peak-to-peak amplitude differences (RISSDV). RR values were extracted by determining the peak frequency of the power spectral density of the four variations and the reference respiratory signal. We assessed each feature's performance by computing the root-mean-squared (RMSE) and mean absolute errors (MAE). RISSDV errors were significantly lower than those of RIAV (RMSE and MAE: p < 0.001), RIIV (RMSE: p < 0.01; MAE p < 0.05), and RIFV (RMSE and MAE: p < 0.001), and it appeared less sensitive to absent or missed PPG pulses than respiratory-induced frequency variations. Further research is necessary to extrapolate these findings to subjects under ambulatory rather than stationary conditions, including pediatric and neonatal populations.

Thermoregulatory responses and ingestive behavior of sheep subjected to water restriction and high- and low-energy diets in a semi-arid environment.

The aim of the study was to evaluate the effect of water restriction and low- and high-energy diets on sheep's thermoregulatory responses and ingestive behavior. Forty sheep, non-castrated, with an average body weight of 18.85 kg (SD = 2.80 kg) and an average age of 5 months were assigned to a 2 × 2 factorial arrangement, comprising 2 diets (high- and low-energy) and 2 water offers (ad libitum and 50% water restriction), with 10 replicates. Thermoregulatory responses were evaluated in two periods (morning and afternoon). There was an interaction effect of Diet x Water supply x Periods on respiratory rate (P < 0.05). High-energy diets resulted in increased heart rate, idleness, dry matter feeding and rumination efficiency, and water intake. Low-energy diets increased feeding time, rumination time, the number of ruminal cuds, chews per day, total chewing time, neutral detergent fiber intake and rumination efficiency, number of ruminations per day, average duration of rumination, and defecation frequency. Water supply affected heart rate and idleness (P < 0.05). Sheep had higher values of heart rate and rectal and surface temperatures during the afternoon (P < 0.05). Water restriction combined with a low-energy diet and high environmental temperature leads to a reduction in the respiratory rate of Santa Inês crossbred sheep. Regardless of the dietary energy value, water restriction by 50% of the daily requirement of sheep reduces dry matter intake and increases idleness.

The respiratory oxygenation index for identifying the risk of orotracheal intubation in COVID-19 patients receiving high-flow nasal cannula oxygen / Índice de oxigenação respiratória para identificar risco de intubação orotraqueal em pacientes com COVID-19 que recebem oxigênio por cânula nasal de alto fluxo

ABSTRACT Objective: To assess whether the respiratory oxygenation index (ROX index) measured after the start of high-flow nasal cannula oxygen therapy can help identify the need for intubation in patients with acute respiratory failure due to coronavirus disease 2019. Methods: This retrospective, observational, multicenter study was conducted at the intensive care units of six Brazilian hospitals from March to December 2020. The primary outcome was the need for intubation up to 7 days after starting the high-flow nasal cannula. Results: A total of 444 patients were included in the study, and 261 (58.7%) were subjected to intubation. An analysis of the area under the receiver operating characteristic curve (AUROC) showed that the ability to discriminate between successful and failed high-flow nasal cannula oxygen therapy within 7 days was greater for the ROX index measured at 24 hours (AUROC 0.80; 95%CI 0.76 - 0.84). The median interval between high-flow nasal cannula initiation and intubation was 24 hours (24 - 72), and the most accurate predictor of intubation obtained before 24 hours was the ROX index measured at 12 hours (AUROC 0.75; 95%CI 0.70 - 0.79). Kaplan-Meier curves revealed a greater probability of intubation within 7 days in patients with a ROX index ≤ 5.54 at 12 hours (hazard ratio 3.07; 95%CI 2.24 - 4.20) and ≤ 5.96 at 24 hours (hazard ratio 5.15; 95%CI 3.65 - 7.27). Conclusion: The ROX index can aid in the early identification of patients with acute respiratory failure due to COVID-19 who will progress to the failure of high-flow nasal cannula supportive therapy and the need for intubation.

RESUMO Objetivo: Avaliar se o índice de oxigenação respiratória medido após o início da terapia de oxigênio com cânula nasal de alto fluxo pode ajudar a identificar a necessidade de intubação em pacientes com insuficiência respiratória aguda devido à COVID-19. Métodos: Este estudo retrospectivo, observacional e multicêntrico foi realizado nas unidades de terapia intensiva de seis hospitais brasileiros, de março a dezembro de 2020. O desfecho primário foi a necessidade de intubação até 7 dias após o início da cânula nasal de alto fluxo. Resultados: O estudo incluiu 444 pacientes; 261 (58,7%) foram submetidos à intubação. Uma análise da área sob a curva receiver operating characteristic (ASC ROC) mostrou que a capacidade de discriminar entre o sucesso e o fracasso da oxigenoterapia com cânula nasal de alto fluxo dentro de 7 dias foi maior para o índice de oxigenação respiratória medido em 24 horas (ASC ROC 0,80; IC95% 0,76 - 0,84). O intervalo médio entre o início da cânula nasal de alto fluxo e a intubação foi de 24 horas (24 - 72), e o preditor mais preciso de intubação obtido antes de 24 horas foi o índice de oxigenação respiratória medido em 12 horas (ASC ROC 0,75; IC95% 0,70 - 0,79). As curvas de Kaplan-Meier revelaram maior probabilidade de intubação em 7 dias em pacientes com índice de oxigenação respiratória ≤ 5,54 em 12 horas (razão de risco 3,07; IC95% 2,24 - 4,20) e ≤ 5,96 em 24 horas (razão de risco 5,15; IC95% 3,65 - 7,27). Conclusões: O índice de oxigenação respiratória pode ajudar na identificação precoce de pacientes com insuficiência respiratória aguda devido à COVID-19 que evoluirão para o fracasso da terapia de suporte com cânula nasal de alto fluxo e a necessidade de intubação.

Non-invasive methods to quantify the carcass parameters of sheep: Interaction between thermal environment and residual feed intake.

The thermal environment is important in unit production because the perception of thermal stress can reduce fertility, and productive performance, therefore its management is necessary. The use of non-invasive methods, such as infrared thermography and real-time ultrasonography, are widely used to evaluate indicators in animal production, without the need to slaughter the animals. Thus, we aimed to assess the effect of the thermal environment on the physiological parameters and carcass characteristics of Dorper sheep with positive and negative residual feed intake (RFI) using infrared thermography and real-time ultrasonography techniques. Twenty uncastrated male Dorper sheep (17.8 ± 2.4 kg) were confined for 40 days for RFI classification. Sheep were separated into positive RFI (n = 10) and negative RFI (n = 10). The experimental design was in randomized blocks, in a 2 × 2 factorial arrangement, with 2 thermal environments (full sun or shade) and two feed efficiency groups (positive RFI or negative RFI), with 5 replications. The sheep remained in confinement for 60 days. The animals were slaughtered at the end of the experiment and the carcasses dissected for tissue separation. Rectal temperature (RT) and respiratory rate (RR) were measured at two times (14:00 h and 18:00 h) for periods of 5 days. The RR was determined by indirect auscultation of heart sounds at the level of the laryngotracheal region. The RT was measured introduced a digital clinical thermometer into the animal's rectum. Surface temperature (ST) was obtained using a thermographic infrared camera, collecting the temperatures of the eyeball and skin surface in the regions of the head, ribs, rump, flank and shin. Sheep confined in full sun showed higher RR (P = 0.0001), ST ribs (P = 0.0020), ST rumb (P = 0.0055), ST flank (P = 0.0001) and heat tolerance coefficient (HTC) (P = 0.0010). For sheep confined in full sun, a strong correlation was observed between the RR and the mean ST (MST; r = 0.6826; P = 0.0236) and between the final loin eye area (LEAf) with the real LEA (LEAr) (r = 0.9263; P = 0.0001) and slaughter body weight (SBW) (r = 0.7532; P = 0.0325). For negative RFI sheep, a positive correlation was observed between the RR and the ST rump (r = 0.7343; P = 0.0025) and ST ribs (r = 0.6560; P = 0.0178) and the MST (r = 0.7435; P = 0.0001), between the MST and the LEAr (r = 0.6837; P = 0.0025) and the final LEA (r = 0.6771; P = 0.0144), and between the final LEA and LEAr (r = 0.9942; P = 0.0001), BW (r = 0.8415; P = 0.0277) and MST (r = 0.6771; P = 0.0045). Positive RFI sheep confined to shade showed a high correlation between final LEA and LEAr (r = 0.9372; P = 0.0001). The use of shading in confined Dorper sheep, regardless of the RFI classification, reduces the effects of heat stress on physiological parameters.

Internet of medical things. Measurement of respiratory dynamics using wearable sensors in post-COVID-19 patients.

Nowadays, the measurement of respiratory dynamics is underrated at clinical setting and in the daily life of a subject and it still represents a challenge from a technical and medical point of view. In this article we propose a concept to measure some of its parameters, such as the respiratory rate (RR), using four inertial sensors. Two different experiments were performed to validate the concept. We analyzed the most suitable placement of each sensor to assess those features and we studied the reliability of the system to measure abnormal parameters of respiration (tachypnea, bradypnea and breath holding). Finally, we measured post-COVID-19 patients, some of them with breath alterations after more than a year of the diagnosis. Experimental results showed that the proposed system could be potentially used to measure the respiratory dynamics at clinical setting. Moreover, while RR can be easily calculated by any sensor, other parameters need to be measured with a sensor in a particular position.

Hoy en día, la medición de la dinámica respiratoria está infravalorada en el ámbito clínico y en la vida diaria de un sujeto y sigue representando un reto desde el punto de vista técnico y médico. En este artículo proponemos un concepto para medir algunos de sus parámetros, como la frecuencia respiratoria (FR), utilizando cuatro sensores inerciales. Se realizaron dos experimentos diferentes para validar el concepto. Analizamos la colocación más adecuada de cada sensor para evaluar esas características y estudiamos la fiabilidad del sistema para medir parámetros anormales de la respiración (taquipnea, bradipnea y retención de la respiración). Por último, realizamos mediciones en pacientes post-COVID-19, algunos de ellos con alteraciones respiratorias después de más de un año del diagnóstico. Los resultados experimentales mostraron que el sistema propuesto podría utilizarse potencialmente para medir la dinámica respiratoria en el ámbito clínico. Además, mientras que la FR puede calcularse fácilmente con cualquier sensor, otros parámetros deben medirse con un sensor en una posición determinada.

Application of thermography to estimate respiratory rate in the emergency room: The journal Temperature toolbox.

Among the vital signs collected during hospital triage, respiratory rate is an important parameter associated with physiological, pathophysiological, and emotional changes. In recent years, the importance of its verification in emergency centers due to the severe acute respiratory syndrome 2 (SARS2) pandemic has become very clear, although it is still one of the least evaluated and collected vital signs. In this context, infrared imaging has been shown to be a reliable estimator of respiratory rate, with the advantage of not requiring physical contact with patients. The objective of this study was to evaluate the potential of analyzing a sequence of thermal images as an estimator of respiratory rate in the clinical routine of an emergency room. We used an infrared thermal camera (T540, Flir Systems) to obtain the respiratory rate data of 136 patients, based on nostrils' temperature fluctuation, during the peak of the COVID-19 pandemic in Brazil and compared it with the chest incursion count method, commonly employed in the emergency screening procedures. We found a good agreement between both methods, with Bland-Altman limits of agreement ranging from -4 to 4 min-1, no proportional bias (R2 = 0.021, p = 0.095), and a strong correlation between them (r = 0.95, p < 0.001). Our results suggest that infrared thermography has potential to be a good estimator of respiratory rate in the routine of an emergency room.

Parental Ability to Assess Pediatric Vital Signs.

OBJECTIVE: To evaluate parents' ability to accurately assess their child's heart and respiratory rates (RRs) in the context of potential utility for telehealth visits. STUDY DESIGN: In this controlled study of 203 child-parent pairs, parents measured their child's heart rate (HR) using 4 methods: palpation, auscultation, and 2 photoplethysmographic smartphone applications. Parents measured RR by inspecting the child and tapping the smartphone application. The gold standards were electrocardiogram for the HR and the child's breaths measured by a health care professional for 60 seconds for the RR. We plotted the measurements using a Bland-Altman plot with 95% limits of agreement. RESULTS: Parents underestimated HR by palpation with a calculated bias of -18 beats per minute (bpm) (SD, 19), with limits of agreement ranging from -56 to 19 bpm. Parents overestimated and underestimated HR by auscultation with limits of agreement ranging from -53 to 46 bpm. Smartphone applications did not improve the accuracy of measurements. The accuracy of parental RR measurements was low. For young children, bias was -0.8 breaths per minute (brpm) (SD, 9.8) with limits of agreement from -20 to 19 brpm, and for older children, bias was 0.9 brpm (SD 7.4) with limits of agreement from 6 to 15 brpm. The sensitivity of parental subjective opinion to recognize accelerated RR was 37% (95% CI, 25%-51%). CONCLUSION: Parents were not able to assess their child's RR or HR accurately. Digital remote assessment of children should not rely on parental measurements of vital signs.

The influence of N95 and FFP2 masks on cardiorespiratory variables in healthy individuals during aerobic exercise: a systematic review and meta-analysis / A influência das máscaras N95 e PFF2 sobre variáveis cardiorrespiratórias em indivíduos saudáveis durante o exercício aeróbico: revisão sistemática e meta-análise

ABSTRACT Objective: In view of the current COVID-19 pandemic, the objective of this study was to determine, through a systematic review and meta-analysis, whether the use of N95/FFP2 masks during aerobic exercise has a significant impact on HR, RR, SpO2, and blood pressure (BP) in healthy individuals. Methods: We searched the MEDLINE database for studies published in English between 2005 and 2021. To reduce bias and increase reliability, only randomized controlled trials and randomized crossover clinical trials were considered for inclusion. The selected outcomes included HR, RR, SpO2, and BP, with perceived exertion being evaluated by means of the Borg scale. Results: Eight controlled trials were included in the meta-analysis. Seven evaluated HR (p > 0.05), five evaluated RR (p > 0.05), five evaluated SpO2 and BP (p > 0.05 for both), and six evaluated perceived exertion, presenting controversial results such as risk ratios that were grouped for each variable. Conclusions: This study suggests that N95 and FFP2 masks do not have significant effects on HR, RR, SpO2, and BP during aerobic exercise in healthy individuals.

RESUMO Objetivo: Diante da atual pandemia de COVID-19, o objetivo deste estudo foi determinar, por meio de uma revisão sistemática e meta-análise, se o uso de máscaras N95/PFF2 durante o exercício aeróbico tem impacto significativo na FC, FR, SpO2 e pressão arterial (PA) em indivíduos saudáveis. Métodos: Buscamos no banco de dados MEDLINE estudos publicados em inglês entre 2005 e 2021. Para reduzir o viés e aumentar a confiabilidade, foram considerados para inclusão no estudo somente ensaios clínicos controlados randomizados e ensaios clínicos cruzados randomizados. Os desfechos selecionados foram FC, FR, SpO2 e PA; a percepção de esforço foi avaliada por meio da escala de Borg. Resultados: Oito ensaios controlados foram incluídos na meta-análise. Sete avaliaram FC (p > 0,05), cinco avaliaram FR (p > 0,05), cinco avaliaram SpO2 e PA (p > 0,05 para ambas) e seis avaliaram a percepção de esforço, com resultados controversos (razões de risco agrupadas para cada variável, por exemplo). Conclusões: Este estudo sugere que as máscaras N95 e PFF2 não têm efeitos significativos na FC, FR, SpO2 e PA durante o exercício aeróbico em indivíduos saudáveis.

Productive, physiological and behavioral sheep profiles housed on facilities with different roofs in the Amazon region

The Brazilian Amazon region is characterized by high rainfall, with high temperatures and relative humidity, where sheep are raised in extensive and semi-intensive systems and some regions. This work aimed to evaluate the climatic indices of sheepfolds in the Amazon region, the productive performance, and physiological variables of Santa Inês sheep confined in sheepfolds with fiber cement (FC) and polyvinyl chloride (PC) tiles. Twenty castrated males of Santa Inês sheep were used, with a mean age of 1.5±0.2 years old and a live weight of 23±2.1 kg. The statistical design used was a completely randomized design with two roofs (FC and PC). The temperature, relative humidity of the air, temperature index of the black globe, and thermal radiation load was above the comfort zone for sheep, being higher (P < 0.05) in the sheepfold with PVC tile than FC, which contributed to the increase in respiratory rate, as a way to maintain the animals' homeotherm. Furthermore, sheep installed in the sheepfold with FC tile showed the highest weight gain, spent more time feeding, increased feeding efficiency, dry matter and fiber intake, reducing daily water intake.

Índice de Oxigenação Respiratória prevê falha de pós-extubação com cânula nasal de alto fluxo em pacientes de unidade de terapia intensiva: estudo de coorte retrospectivo / The Respiratory Rate-Oxygenation Index predicts failure of post-extubation high-flow nasal cannula therapy in intensive care unit patients: a retrospective cohort study

RESUMO Objetivo: Investigar a aplicabilidade do Índice de Oxigenação Respiratória para identificar o risco de falha de cânula nasal de alto fluxo em pacientes com pneumonia. Métodos: Este estudo retrospectivo observacional de 2 anos foi realizado em um hospital de referência em Bogotá, na Colômbia. Incluíram-se no estudo todos os pacientes em que foi utilizada cânula nasal de alto fluxo pós-extubação como terapia-ponte para a extubação. O Índice de Oxigenação Respiratória foi calculado para avaliar o risco de falha pós-extubação de cânula nasal de alto fluxo. Resultados: Incluíram-se no estudo 162 pacientes. Destes, 23,5% apresentaram falha de cânula nasal de alto fluxo. O Índice de Oxigenação Respiratória foi significativamente menor em pacientes que tiveram falha de cânula nasal de alto fluxo. A mediana (IQ 25 - 75%) foi de 10,0 (7,7 - 14,4) versus 12,6 (10,1 - 15,6), com p = 0,006. O Índice de Oxigenação Respiratória > 4,88 apresentou razão de chances bruta de 0,23 (IC95% 0,17 - 0,30) e RC ajustada de 0,89 (IC95% 0,81 - 0,98) estratificada por gravidade e comorbidade. Após a análise de regressão logística, o Índice de Oxigenação Respiratória apresentou razão de chances ajustada de 0,90 (IC95% 0,82 - 0,98; p = 0,026). A área sob a curva Receiver Operating Characteristic para falha de extubação foi de 0,64 (IC95% 0,53 - 0,75; p = 0,06). O Índice de Oxigenação Respiratória não apresentou diferenças entre pacientes que sobreviveram e que morreram durante internação na unidade de terapia intensiva. Conclusão: O Índice de Oxigenação Respiratória é uma ferramenta acessível para identificar pacientes em risco de falha no tratamento pós-extubação com cânulas nasais de alto fluxo. Estudos prospectivos são necessários para ampliar a utilidade nesse cenário.

ABSTRACT Objective: To investigate the applicability of the Respiratory Rate-Oxygenation Index to identify the risk of high-flow nasal cannula failure in post-extubation pneumonia patients. Methods: This was a 2-year retrospective observational study conducted in a reference hospital in Bogotá, Colombia. All patients in whom post-extubation high-flow nasal cannula therapy was used as a bridge to extubation were included in the study. The Respiratory Rate-Oxygenation Index was calculated to assess the risk of post-extubation high-flow nasal cannula failure. Results: A total of 162 patients were included in the study. Of these, 23.5% developed high-flow nasal cannula failure. The Respiratory Rate-Oxygenation Index was significantly lower in patients who had high-flow nasal cannula failure [median (IQR): 10.0 (7.7 - 14.4) versus 12.6 (10.1 - 15.6); p = 0.006]. Respiratory Rate-Oxygenation Index > 4.88 showed a crude OR of 0.23 (95%CI 0.17 - 0.30) and an adjusted OR of 0.89 (95%CI 0.81 - 0.98) stratified by severity and comorbidity. After logistic regression analysis, the Respiratory Rate-Oxygenation Index had an adjusted OR of 0.90 (95%CI 0.82 - 0.98; p = 0.026). The area under the Receiver Operating Characteristic curve for extubation failure was 0.64 (95%CI 0.53 - 0.75; p = 0.06). The Respiratory Rate-Oxygenation Index did not show differences between patients who survived and those who died during the intensive care unit stay. Conclusion: The Respiratory Rate-Oxygenation Index is an accessible tool to identify patients at risk of failing high-flow nasal cannula post-extubation treatment. Prospective studies are needed to broaden the utility in this scenario.

Ventilador mecânico invasivo de emergência resistente e de fácil manutenção / Robust, maintainable, emergency invasive mechanical ventilator

RESUMO Objetivo: Desenvolver um ventilador mecânico invasivo simples, resistente, seguro e eficiente que possa ser utilizado em áreas remotas do mundo ou zonas de guerra, em que a utilidade prática de equipamentos mais sofisticados é limitada por questões de manutenção, disponibilidade de peças, transporte e/ou custo. Métodos: O dispositivo implementa o modo de ventilação mandatória contínua com pressão controlada, complementado por um simples modo assisto-controlado. Pode-se também utilizar a pressão positiva contínua nas vias aéreas. Ao se evitar o fluxo contínuo de oxigênio ou ar, minimiza-se o consumo de gases comprimidos. As taxas respiratórias e as relações de tempo de inspiração e expiração são determinadas eletronicamente. Além disso, conta com um alarme de apneia/falta de energia. Resultados: Os perfis de pressão foram medidos para uma série de condições, sendo considerados ajustáveis dentro de uma margem de erro de ± 2,5cmH2O, e foram considerados bem estáveis dentro dessa variação durante um período de 41 horas. Os parâmetros de tempo do ciclo respiratório foram precisos dentro de alguns pontos percentuais durante o mesmo período. O dispositivo foi testado quanto à durabilidade por um período equivalente a 4 meses. Os testes químicos e biológicos não conseguiram identificar qualquer contaminação do gás por compostos orgânicos voláteis ou micro-organismos. Em comparação com um ventilador bem estabelecido, o teste de ventilação em um animal de grande porte mostrou que este poderia ser ventilado adequadamente durante um período de 60 minutos, sem quaisquer efeitos negativos perceptíveis durante o período subsequente de 24 horas. Conclusão: Este projeto de ventilador pode ser viável após novos testes em animais e aprovação formal pelas autoridades competentes, para aplicação clínica nas circunstâncias atípicas anteriormente mencionadas.

ABSTRACT Objective: To develop a simple, robust, safe and efficient invasive mechanical ventilator that can be used in remote areas of the world or war zones where the practical utility of more sophisticated equipment is limited by considerations of maintainability, availability of parts, transportation and/or cost. Methods: The device implements the pressure-controlled continuous mandatory ventilation mode, complemented by a simple assist-control mode. Continuous positive airway pressure is also possible. The consumption of compressed gases is minimized by avoiding a continuous flow of oxygen or air. Respiratory rates and inspiration/expiration time ratios are electronically determined, and an apnea/power loss alarm is provided. Results: The pressure profiles were measured for a range of conditions and found to be adjustable within a ± 2.5cmH2O error margin and stable well within this range over a 41-hour period. Respiratory cycle timing parameters were precise within a few percentage points over the same period. The device was tested for durability for an equivalent period of four months. Chemical and biological tests failed to identify any contamination of the gas by volatile organic compounds or microorganisms. A ventilation test on a large animal, in comparison with a well established ventilator, showed that the animal could be adequately ventilated over a period of 60 minutes, without any noticeable negative aftereffects during the subsequent 24-hour period. Conclusion: This ventilator design may be viable, after further animal tests and formal approval by the competent authorities, for clinical application in the abovementioned atypical circumstances.

Autonomic and cardiorespiratory responses to the active tilt test in individuals with Parkinson disease: cross-sectional study / Respostas autonômicas e cardiorrespiratórias ao teste ativo de inclinação em indivíduos com doença de Parkinson: estudo transversal

Abstract Background The Parkinson disease (PD) is frequently associated with autonomic dysfunctions. However, data regarding the influence of PD on the autonomic responses to postural changes is limited. Objective To analyze and compare the autonomic responses, evaluated through linear and non-linear methods of heart rate variability, and cardiorespiratory parameters in two groups: Parkinson disease (PDG) and control (CG), at rest and during the active tilt test. Methods A total of 48 participants were analyzed (PDG: n = 25;73.40 ± 7.01 years / CG: n = 23;70.17 ± 8.20 years). The autonomic modulation and cardiorespiratory parameters were evaluated at rest and during the active tilt test. To assess the autonomic modulation the linear indices, at the time (rMSSD, SDNN) and frequency (LF, HF, LF/HF) domains, and the non-linear indices, obtained through the Poincaré plot (SD1, SD2, SD1/SD2), were calculated. The cardiorespiratory parameters evaluated were heart rate (HR), systolic (SBP), and diastolic blood pressure (DBP), peripheral oxygen saturation (SpO2), and respiratory rate. Results At rest, the PDG presented significantly lower values of rMSSD, SDNN, LF, HF, SD1, SD2, and DBP, and higher values of SpO2. During test, in the PD group, modifications were observed in HR, and SBP, besides a reduced parasympathetic response, and an increased global modulation. The qualitative analysis of the Poincaré plot showed that the PDG has a lower dispersion of the RR intervals during rest and the active tilt test. Conclusion Individuals with PD present reduced global variability and parasympathetic modulation at rest, and reduced parasympathetic response and damage in HR regulation when performing the active tilt test, compared with controls.

Resumo Antecedentes A doença de Parkinson (DP) está frequentemente associada a disfunções autonômicas. Porém, dados sobre a influência da DP nas respostas autonômicas às mudanças posturais são limitados. Objetivos Analisar e comparar as respostas autonômicas, avaliadas por métodos lineares e não lineares de variabilidade da frequência cardíaca e parâmetros cardiorrespiratórios em dois grupos: DP (GDP) e controle (CG), em repouso e durante o tilt test ativo. Métodos Foram analisados 48 participantes (GDP: n = 25;73,40 ± 7,01 anos/GC: n = 23; 70,17 ± 8,20 anos). A modulação autonômica e os parâmetros cardiorrespiratórios foram avaliados em repouso e durante o tilt test ativo. Para avaliar a modulação autonômica foram calculados os índices lineares, nos domínios do tempo (rMSSD, SDNN) e frequência (LF, HF, LF/HF), e os índices não lineares, obtidos através do plot de Poincaré (SD1, SD2, SD1/SD2). Os parâmetros cardiorrespiratórios avaliados foram frequência cardíaca (FC), pressão arterial sistólica (PAS), diastólica (PAD), saturação periférica de oxigênio (SpO2) e frequência respiratória. Resultados Em repouso, o GDP apresentou valores menores de rMSSD, SDNN, LF, HF, SD1, SD2 e PAD, e maiores valores de SpO2. No teste, foram observadas modificações na FC e na PAS, redução da resposta parassimpática e aumento da modulação global no GDP. A análise qualitativa do plot de Poincaré mostrou que o GDP apresentou menor dispersão dos intervalos RR no repouso e no tilt test ativo. Conclusão Indivíduos com DP apresentam redução da variabilidade global e modulação parassimpática em repouso, redução da resposta parassimpática e prejuízo na regulação da FC ao realizar o tilt test ativo, em comparação aos controles.

Early Initiation of Extracorporeal Blood Purification Using the AN69ST (oXiris®) Hemofilter as a Treatment Modality for COVID-19 Patients: a Single-Centre Case Series

Abstract Introduction: Severe coronavirus disease 2019 (COVID-19) is characterised by hyperinflammatory state, systemic coagulopathies, and multiorgan involvement, especially acute respiratory distress syndrome (ARDS). We here describe our preliminary clinical experience with COVID-19 patients treated via an early initiation of extracorporeal blood purification combined with systemic heparinisation and respiratory support. Methods: Fifteen patients were included; several biomarkers associated with COVID-19 severity were monitored. Personalised treatment was tailored according to the levels of interleukin (IL)-6, IL-8, tumour necrosis factor alpha, C-reactive protein (CRP), neutrophil-to-lymphocyte ratio, thrombocyte counts, D-dimers, and fibrinogen. Treatment consisted of respiratory support, extracorporeal blood purification using the AN69ST (oXiris®) hemofilter, and 300 U/kg heparin to maintain activation clotting time ≥ 180 seconds. Results: Ten patients presented with severe to critical disease (dyspnoea, hypoxia, respiratory rate > 30/min, peripheral oxygen saturation < 90%, or > 50% lung involvement on X-ray imaging). The median intensive care unit length of stay was 9.3 days (interquartile range 5.3-10.1); two patients developed ARDS and died after 5 and 26 days. Clinical improvement was associated with normalisation (increase) of thrombocytes and white blood cells, stable levels of IL-6 (< 50 ng/mL), and a decrease of CRP and fibrinogen. Conclusion: Continuous monitoring of COVID-19 severity biomarkers and radiological imaging is crucial to assess disease progression, uncontrolled inflammation, and to avert irreversible multiorgan failure. The combination of systemic heparin anticoagulation regimens and extracorporeal blood purification using cytokine-adsorbing hemofilters may reduce hyperinflammation, prevent coagulopathy, and support clinical recovery.

Physiological responses, water consumption, and feeding behaviour of lamb breeds fed diets containing different proportions of concentrate

The use of adapted breeds, such as Santa Inês, is of paramount importance for regions with high temperatures because they develop efficient mechanisms for heat dissipation. Furthermore, some breeds have physiological adaptations, such as more efficient mechanisms for the digestion of fibrous foods (e.g. Rabo Largo), which can reduce the harmful effects of semiarid environments. We studied the ingestive behaviour, water consumption, and physiological parameters during feeding of two native sheep breeds fed diets containing high (700 g/kg DM; HC diet) or low (300 g/kg DM; LC diet) percentages of concentrates, based on dry matter (DM). A total of 40 uncastrated male lambs (20 Rabo Largo [breed 1] and 20 Santa Inês [breed 2], with an average body weight of 16.68 ± 2.78 kg, and 19.29 kg ± 3.28 kg, respectively), were distributed in a randomised block design in a two-by-two factorial scheme (breeds × diets) with 10 repetitions. Santa Inês lambs consumed and ruminated DM (P = 0.029 for both) and neutral detergent fibre (NDF; P = 0.001 and P = 0.004, respectively) more efficiently than RaboLargo lambs, while the latter showed an increase in respiratory rate (+19 breaths/min) and rectal temperature (+1.3 °C) compared to the Santa Inês lambs (P = 0.001). The HC diet negatively affected (P < 0.05) the feeding behaviour of the animals, reflecting the higher (P < 0.05) water consumption. The results showed that diets rich in concentrate negatively affected the thermoregulation of lambs. Santa Inês have greater feed and thermoregulatory efficiency than Rabo Largo lambs under conditions of heat stress in the feedlot.(AU)

Physiological responses, water consumption, and feeding behaviour of lamb breeds fed diets containing different proportions of concentrate

The use of adapted breeds, such as Santa Inês, is of paramount importance for regions with high temperatures because they develop efficient mechanisms for heat dissipation. Furthermore, some breeds have physiological adaptations, such as more efficient mechanisms for the digestion of fibrous foods (e.g. Rabo Largo), which can reduce the harmful effects of semiarid environments. We studied the ingestive behaviour, water consumption, and physiological parameters during feeding of two native sheep breeds fed diets containing high (700 g/kg DM; HC diet) or low (300 g/kg DM; LC diet) percentages of concentrates, based on dry matter (DM). A total of 40 uncastrated male lambs (20 Rabo Largo [breed 1] and 20 Santa Inês [breed 2], with an average body weight of 16.68 ± 2.78 kg, and 19.29 kg ± 3.28 kg, respectively), were distributed in a randomised block design in a two-by-two factorial scheme (breeds × diets) with 10 repetitions. Santa Inês lambs consumed and ruminated DM (P = 0.029 for both) and neutral detergent fibre (NDF; P = 0.001 and P = 0.004, respectively) more efficiently than RaboLargo lambs, while the latter showed an increase in respiratory rate (+19 breaths/min) and rectal temperature (+1.3 °C) compared to the Santa Inês lambs (P = 0.001). The HC diet negatively affected (P < 0.05) the feeding behaviour of the animals, reflecting the higher (P < 0.05) water consumption. The results showed that diets rich in concentrate negatively affected the thermoregulation of lambs. Santa Inês have greater feed and thermoregulatory efficiency than Rabo Largo lambs under conditions of heat stress in the feedlot.