Study of heart rate recovery and cardiovascular autonomic modulation in healthy participants after submaximal exercise.

Heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS) provide important information on cardiovascular autonomic control. However, little is known about the reorganization of HRV, BPV, and BRS after aerobic exercise. While there is a positive relationship between heart rate (HR) recovery rate and cardiorespiratory fitness, it is unclear whether there is a relationship between cardiorespiratory fitness and reorganization of cardiovascular autonomic modulation during recovery. Thus, this study aimed to investigate whether cardiorespiratory fitness influences the cardiovascular autonomic modulation recovery, after a cardiopulmonary exercise test. Sixty men were assigned into groups according to their cardiorespiratory fitness: low cardiorespiratory fitness (LCF = VO2: 22-38 mL kg-1 min-1), moderate (MCF = VO2: 38-48 mL kg-1 min-1), and high (HCF = VO2 > 48 mL kg-1 min-1). HRV (linear and non-linear analysis) and BPV (spectral analysis), and BRS (sequence method) were performed before and after a cardiopulmonary exercise test. The groups with higher cardiorespiratory fitness had lower baseline HR values and HR recovery time after the cardiopulmonary exercise test. On comparing rest and recovery periods, the spectral analysis of HRV showed a decrease in low-frequency (LF) oscillations in absolute units and high frequency (HF) in absolute and normalized units. It also showed increases in LF oscillations of blood pressure. Nonlinear analysis showed a reduction in approximate entropy (ApEn) and in Poincare Plot parameters (SD1 and SD2), accompanied by increases in detrended fluctuation analysis (DFA) parameters α1 and α2. However, we did not find differences in cardiovascular autonomic modulation parameters and BRS in relation to cardiorespiratory fitness neither before nor after the cardiopulmonary test. We concluded that cardiorespiratory fitness does not affect cardiovascular autonomic modulations after cardiopulmonary exercise test, unlike HR recovery.

Important differences between hypertensive middle-aged women and men in cardiovascular autonomic control-a critical appraisal.

BACKGROUND: Normotensive premenopausal women show a vagal predominance of cardiac autonomic modulation, whereas age-matched men show a predominance of sympathetic modulation. However, some women develop systemic arterial hypertension (SAH) even with preserved ovarian function. Our hypothesis is that these women may have cardiovascular autonomic parameters similar to those of hypertensive men, even when subjected to pharmacological treatment. We aimed to investigate cardiovascular autonomic control and baroreflex sensitivity (BRS) in hypertensive premenopausal women and age-matched men. METHODS: One hundred volunteers between 18 and 45 years of age were assigned to two groups (50 participants each): a hypertensive group including patients with a history of SAH for at least 6 months (25 men and 25 women), who were under treatment with monotherapy (losartan, 25-50 mg/kg); and a normotensive group (25 men and 25 women). Anthropometric, hemodynamic, metabolic, and autonomic cardiovascular assessments were performed focusing on BRS, autonomic modulation of heart rate variability (HRV), and blood pressure variability (BPV). RESULTS: On HRV analysis, women showed higher values of high-frequency (HF) oscillations in absolute and normalized units, lower values ​of low-frequency (LF) in normalized units, and lower LF/HF ratio, as compared with men. When the normotensive and hypertensive groups were compared, hypertensive groups showed lower values ​of total variance and of LF and HF bands in absolute units. On BRS, hypertensive groups showed lower values than the normotensive group. CONCLUSION: Regardless of blood pressure control through pharmacological treatment, hypertensive patients continued to have reduced HRV compared to normotensive, and hypertensive men had more autonomic impairment than hypertensive premenopausal women.

Spanish version of the Perme Intensive Care Unit Mobility Score: Minimal detectable change and responsiveness.

PURPOSE: The purpose of this study was to determine the minimal detectable change (MDC) and responsiveness of the Perme Score when used in the adult intensive care unit (ICU) population. METHODS: This is a prospective longitudinal study which was conducted from November 2016 to July 2017 in Cali, Colombia. Four physical therapists with observer and evaluator roles, applied the Perme Score upon ICU admission and discharge. The Consensus-based Standards for the Selection of Health Measurement Instruments Protocol standards to analyze sensitivity to change were used. The sample size was defined considering the lowest concordance proportion reported (68.6%), and a Kappa Index of 0.2784 or higher to guarantee an adequate n, and a 95% reliability level. RESULTS: One hundred and forty-two patients were enrolled in the study. There were 51.4% men with an average age of 58 ± 17 years. Invasive mechanical ventilation was employed in 42.0% of the patients. The MDC for the Perme Score was 1.36, and 80% of patients demonstrated higher or equal values, detecting a significant difference in the type of weaning and the length of stay in the ICU (p < 0.005). CONCLUSIONS: The Perme Score has an MDC of 1.36 points and shows evidence of being sensitive to change. Therefore, the findings validate the responsiveness of the instrument.

Early ovarian hormone deprivation increases cardiac contractility in old female rats-Role of physical training.

OBJECTIVES: We investigated the effects of early ovarian hormones deprivation on morphology and cardiac function and the effects of aerobic training on these parameters, in old rats. METHODS: Female Wistar rats (N = 48) were divided into two groups, at 10 weeks of life: early ovarian hormones deprivation by ovariectomy (OVX; N = 24) and sham (SHAM; N = 24). Between weeks 62 and 82, 12 animals of each group underwent aerobic training (OVX-T and SHAM-T, N = 12). At the end of week 82, all were evaluated by echocardiography, cardiac function (Langendorff technique) and cardiac ß-adrenergic receptor expression quantification. RESULTS: Echocardiography showed slight changes in morphology between OVX and SHAM groups. OVX group (Δ = 101 ±â€¯4.7 mmHg) showed higher values for maximal left intraventricular pressure in response to dobutamine, when compared to SHAM group (Δ = 55 ±â€¯11.8 mmHg). Both OVX-T (Δ = 70 ±â€¯4.0 mmHg) and SHAM-T (Δ = 22 ±â€¯6.6 mmHg) groups showed a reduction in this response. While, ß-adrenergic receptor expression was not different between the untrained groups, SHAM-T (0.23 ±â€¯0.02 AU) and OVX-T (0.29 ±â€¯0.01 AU), showed decreased expression of these receptors. CONCLUSION: Early ovarian hormones deprivation associated with aging, promotes discrete changes in cardiac morphology and increasing cardiac contractility. Aerobic training decreases ß-adrenergic receptors expression, influencing the cardiac contractility.

The blood pressure variability and baroreflex sensitivity in healthy participants are not determined by sex or cardiorespiratory fitness.

BACKGROUND: Heart rate (HR) and blood pressure (BP) autonomic modulation and baroreflex sensitivity (BRS) are important indexes of cardiovascular homeostasis. However, methodological errors are often observed, such as joint analysis of men and women. Another important aspect is that we still do not know whether cardiorespiratory fitness influences these autonomic parameters in healthy individuals. OBJECTIVES: This study aimed to investigate whether sex can affect BRS, autonomic modulation of HR and BP variabilities (HRV and BPV, respectively), as well as the influence of cardiorespiratory fitness on these autonomic parameters. METHODS: Healthy men and women (N=120) were assigned to groups according to the peak oxygen consumption (VO2 peak) obtained in the cardiorespiratory test: low cardiorespiratory fitness (VO2 peak: 22-38 ml/kg/min), moderate cardiorespiratory fitness (VO2 peak: 38-48 ml/kg/min), and high cardiorespiratory fitness (VO2 peak>48 ml/kg/min). HRV and BPV evaluations were performed for all groups in the frequency domain by spectral analysis. Spontaneous BRS was assessed using the sequence method. RESULTS: Women presented lower BP values compared with men. HR did not differ between sexes, but showed an inverse relationship with cardiorespiratory performance. The HRV analysis showed greater sympathetic modulation for men and greater vagal modulation for women. Men and women presented similar results for systolic BPV and BRS, and cardiorespiratory performance did not influence any of the autonomic parameters evaluated. CONCLUSION: Cardiorespiratory fitness does not interfere with HRV and BPV autonomic modulation or BRS. However, the cardiac modulatory balance differs between sexes, with a greater influence of the autonomic vagal component in women and the sympathetic component in men.

Physical training promotes similar effects to the blockade of angiotensin-converting enzyme on the cardiac morphology and function in old female rats subjected to premature ovarian failure.

We investigated the effects of angiotensin-converting enzyme (ACE) inhibition and aerobic physical training on the heart of old female rats (82-wk-old) submitted to premature ovarian failure (10-wk.-old). We used different approaches: morphology and function by echocardiography, reactivity of the coronary bed and left ventricular contractibility (Langendorff Technique). Female Wistar ovariectomized (OVX) rats (n=42) were assigned to one of four groups: OVX, vehicle treated only; OVX-EM, Enalapril Maleate only (EM, 10mg·kg-1·d-1); OVX-T, aerobic trained only; and OVX-EMT, treated with Enalapril Maleate and aerobic trained. Both Enalapril Maleate treatment and aerobic training were done in the last 20weeks of the experimental protocol. When compared to the OVX group, the OVX-EM group showed lower values of wall thickness and left ventricular (LV) mass, lower values of coronary bed reactivity and reduced maximum response of LV contractility to dobutamine, while the OVX-T group showed lower values of LV wall thickness, increase in end-systolic volume, reduced maximum response of LV contractility to dobutamine, and left intraventricular pressure due to increased flow. The combination of treatments (EM and aerobic physical training) did not promote additional important effects on the parameters evaluated. Our results suggest similar beneficial effects of physical training and EM treatment on the morphology and cardiac function in old female rats submitted to premature ovarian failure. Although the causes of these benefits are still unknown, both treatments have promoted a decrease in cardiac contractility, and the reduced ß1-adrenergic sensitivity suggests that both treatments may attenuate the sympathetic effect on the heart.

Do muscular strength and jump power tests reflect the effectiveness of training programs for basketball athletes?

Muscular strength (MS) and jump power (JP) tests are used to assess athletic ability and measure the effectiveness of training programs. However, their use in various sport modalities needs to be investigated further. This study aimed to explore the changes in MS and JP during three different moments of a macrocycle training session and verify the validity of the tests used to predict the effectiveness of basketball training programs. Methods: During macrocycle training (three different moments), sixteen basketball players were evaluated for MS (measured using isokinetic dynamometry at the speed of 60°/s) during concentric contraction of knee flexor and extensor muscles and JP, using countermovement vertical jump (CMVJ) on a force platform. Results: Peak torque and maximal work values for knee extension and flexion showed no differences, during the three moments analyzed. Additionally, no changes were observed for CMVJ. Conclusions: Our results suggest that the effectiveness of basketball training programs does not seem to be related to the performance achieved by athletes on the tests used. Moreover, the lack of changes in MS and JP values during the macrocycle could be related to the training structure used; volume, intensity, density and workload specificity.(AU)

Polycystic Ovary Syndrome Presents Higher Sympathetic Cardiac Autonomic Modulation that is not altered by Strength Training.

Polycystic ovary syndrome (PCOS) may present important comorbidities, such as cardiovascular and metabolic diseases, which are often preceded by changes in cardiac autonomic modulation. Different types of physical exercises are frequently indicated for the prevention and treatment of PCOS. However, little is known about the effects of strength training on the metabolic, hormonal, and cardiac autonomic parameters. Therefore, our aim was to investigate the effects of strength training on the autonomic modulation of heart rate variability (HRV) and its relation to endocrine-metabolic parameters in women with PCOS. Fifty-three women were divided into two groups: CONTROL (n=26) and PCOS (n=27). The strength training lasted 4 months, which was divided into mesocycles of 4 weeks each. The training load started with 70% of one repetition maximum (1RM). Blood samples were collected before and after intervention for analysis of fasting insulin and glucose, HOMA-IR, testosterone, androstenedione and testosterone/androstenedione (T/A) ratio. Spectral analysis of HRV was performed to assess cardiac autonomic modulation indexes. The PCOS group presented higher insulin and testosterone levels, T/A ratio, along with increased sympathetic cardiac autonomic modulation before intervention. The training protocol used did not cause any change of endocrine-metabolic parameters in the CONTROL group. Interestingly, in the PCOS group, reduced testosterone levels and T/A ratio. Additionally, strength training did not have an effect on the spectral parameter values of HRV obtained in both groups. Strength training was not able to alter HRV autonomic modulation in women with PCOS, however may reduce testosterone levels and T/A ratio.

Amlodipine and enalapril promote distinct effects on cardiovascular autonomic control in spontaneously hypertensive rats: the role of aerobic physical training.

BACKGROUND: We compared the autonomic and hemodynamic cardiovascular effects of amlodipine and enalapril treatment associated with an aerobic physical training program on spontaneously hypertensive rats. METHODS: Eighteen-week-old (n = 48) spontaneously hypertensive rats were assigned to one of two groups: sedentary (n = 24) and trained (n = 24) through a 10-week swimming training program. Each group was subdivided into three groups (n = 8): control (vehicle group), amlodipine (amlodipine group; 10 mg/kg per day) and enalapril (enalapril group; 10 mg/kg per day) (both for 10 weeks). We cannulated the femoral artery and vein of all animals for recording arterial pressure and injecting drugs, respectively. Autonomic assessment was performed by double blockade with propranolol and atropine, analysis of heart rate variability (HRV), systolic arterial pressure variability and baroflex sensitivity. RESULTS: Arterial pressure reduction was more prominent in the sedentary and trained enalapril groups. Amlodipine sedentary group presented important autonomic adjustments characterized by a predominance of vagal tone in cardiac autonomic balance, increased HRV associated with sympathetic autonomic modulation reduction and increased vagal autonomic modulation, and increased baroflex sensitivity. All findings were not potentialized by physical training. In turn, the enalapril trained group, but not its sedentary counterpart, also had vagal tone prevalence in cardiac autonomic balance, increased HRV, increased baroflex sensitivity and decreased low-frequency band in systolic arterial pressure variability. CONCLUSION: Amlodipine was more effective in promoting beneficial autonomic cardiovascular adaptations in sedentary animals. In contrast, enalapril achieved better autonomic results only when combined with aerobic physical training.

Peak expiratory flow in healthy, young, non-active subjects in seated, supine, and prone postures.

OBJECTIVE: To compare the PEFs in healthy, young, non-active subjects in seated, supine, and prone postures. METHODS: A total of 30 healthy volunteers (15 male, mean age 22.7 years, non-smokers, sedentary) underwent a physical examination, spirometry to confirm normal pulmonary function, and PEF using the Mini-Wright Peak Flow Meter while wearing a nose clip. PEF measurements were repeated three times in each of three positions (seated, prone, and supine) in random order and differed by less than 20 L/min for a given position. Paired Student's t-tests were used to analyze the results, and the significance level was set at 5%. RESULTS: The PEF values obtained when the study participants were in a seated position (481.0 ± 115.1 L/min) were higher than those obtained when participants were in prone (453.7 ± 112.1 L/min) or supine (453.2 ± 114.3 L/min) positions (p < 0.05). No significant difference in PEF values was observed between the prone and supine positions. CONCLUSION: Body posture affects PEF in healthy, young, non-active subjects. PEFs are higher when subjects are in a seated position compared to prone or supine positions, but no difference in PEF is observed between the prone and supine positions.

Performance in the 6-minute walk test and postoperative pulmonary complications in pulmonary surgery: an observational study

OBJECTIVES: To assess functional capacity in the preoperative phase of pulmonary surgery by comparing predicted and obtained values for the six-minute walk test (6MWT) in patients with and without postoperative pulmonary complication (PPC) METHOD: Twenty-one patients in the preoperative phase of open thoracotomy were evaluated using the 6MWT, followed by monitoring of the postoperative evolution of each participant who underwent the routine treatment. Participants were then divided into two groups: the group with PPC and the group without PPC. The results were also compared with the predicted values using reference equations for the 6MWT RESULTS: Over half (57.14%) of patients developed PPC. The 6MWT was associated with the odds for PPC (odds ratio=22, p=0.01); the group without PPC in the postoperative period walked 422.38 (SD=72.18) meters during the 6MWT, while the group with PPC walked an average of 340.89 (SD=100.93) meters (p=0.02). The distance traveled by the group without PPC was 80% of the predicted value, whereas the group with PPC averaged less than 70% (p=0.03), with more appropriate predicted values for the reference equations CONCLUSIONS: The 6MWT is an easy, safe, and feasible test for routine preoperative evaluation in pulmonary surgery and may indicate patients with a higher chance of developing PPC.

Performance in the 6-minute walk test and postoperative pulmonary complications in pulmonary surgery: an observational study.

OBJECTIVES: To assess functional capacity in the preoperative phase of pulmonary surgery by comparing predicted and obtained values for the six-minute walk test (6MWT) in patients with and without postoperative pulmonary complication (PPC) METHOD: Twenty-one patients in the preoperative phase of open thoracotomy were evaluated using the 6MWT, followed by monitoring of the postoperative evolution of each participant who underwent the routine treatment. Participants were then divided into two groups: the group with PPC and the group without PPC. The results were also compared with the predicted values using reference equations for the 6MWT RESULTS: Over half (57.14%) of patients developed PPC. The 6MWT was associated with the odds for PPC (odds ratio=22, p=0.01); the group without PPC in the postoperative period walked 422.38 (SD=72.18) meters during the 6MWT, while the group with PPC walked an average of 340.89 (SD=100.93) meters (p=0.02). The distance traveled by the group without PPC was 80% of the predicted value, whereas the group with PPC averaged less than 70% (p=0.03), with more appropriate predicted values for the reference equations CONCLUSIONS: The 6MWT is an easy, safe, and feasible test for routine preoperative evaluation in pulmonary surgery and may indicate patients with a higher chance of developing PPC.

Bilateral Shoulder Dysfunction Related to the Lung Resection Area After Thoracotomy.

This study aimed to investigate the mobility, pain, and disability of the shoulders after different pulmonary surgical procedures.It is a cross-sectional prospective study. A total of 38 patients who underwent lung surgery via thoracotomy (mean age = 57 ±â€Š10 years) were evaluated in the preoperative period, and first and second postoperative days were assessed for range of motion of shoulder; pain intensity; and application of the Shoulder Pain and Disability Index questionnaire. This study compared the 3 days of evaluation, and the subgroups according to the resection area (biopsy/nodulectomy, lung segmentectomy and lobectomy).There was a decrease of flexion (153°â€Š±â€Š16°-98°â€Š±â€Š23°), abduction (151°â€Š±â€Š20°-126°â€Š±â€Š38°), and increased Shoulder Pain and Disability Index (2.4-44.3) in the shoulder ipsilateral to surgery from the preoperative to the first postoperative day (P < 0.05). There was a greater loss of ipsilateral flexion and abduction in the lobectomy subgroup (P < 0.05), and decreased abduction of the contralateral shoulder in the lung segmentectomy and lobectomy subgroups (P < 0.05).After pulmonary surgery, there is bilateral impairment in shoulder range of motion, with greater limitation on ipsilateral shoulder, and larger resections.

Chronic cholinergic stimulation promotes changes in cardiovascular autonomic control in spontaneously hypertensive rats.

Hypertension is often accompanied by autonomic dysfunction, which is detrimental to cardiac regulation. On the other hand, cholinergic stimulation through inhibition of acetylcholinesterase appears to have beneficial effects on cardiac autonomic control. Thus, our objective was to investigate the effects of chronic cholinergic stimulation on hemodynamic and cardiovascular autonomic control parameters in spontaneously hypertensive rats (SHR). For this, 26-week-old SHR (N = 32) and Wistar Kyoto rats (WK; N = 32) were divided into two groups: one treated with vehicle (H2O; N = 16) and the other treated with pyridostigmine bromide (PYR; N = 16) in drinking water (25 mg/kg/day) for 2 weeks. All groups were subjected to recording of arterial pressure (AP) and heart rate (HR), quantification of ejection fraction (EF), evaluation of cardiac tonic autonomic balance by means of double autonomic blockade with methylatropine and propranolol, analysis of systolic AP (SAP) and HR variability (HRV), and evaluation of baroreflex sensitivity (BRS). AP, HR, and EF were reduced in the SHR-PYR group compared with the SHR-H2O group. Evaluation of autonomic parameters revealed an increase in vagal tone participation in cardiac tonic autonomic balance and reduced SAP variability; however, no changes were observed in HRV or BRS. These results suggest that chronic cholinergic stimulation with pyridostigmine bromide promotes reduction in the hemodynamic parameters AP, HR, and EF. Additionally, tonic autonomic balance was improved and a reduction in LF oscillations of SAP variability was observed that could not be attributed to BRS, as the latter did not change. Further studies should be conducted to identify the mechanisms involved in the observed responses.

Physical therapy for airway clearance improves cardiac autonomic modulation in children with acute bronchiolitis

BACKGROUND: The effects of physical therapy on heart rate variability (HRV), especially in children, are still inconclusive. OBJECTIVE: We investigated the effects of conventional physical therapy (CPT) for airway clearance and nasotracheal suction on the HRV of pediatric patients with acute bronchiolitis. METHOD: 24 children were divided into two groups: control group (CG, n=12) without respiratory diseases and acute bronchiolitis group (BG, n=12). The heart rate was recorded in the BG at four different moments: basal recording (30 minutes), 5 minutes after the CPT (10 minutes), 5 minutes after nasotracheal suction (10 minutes), and 40 minutes after nasotracheal suction (30 minutes). The CG was subjected to the same protocol, except for nasotracheal suction. To assess the HRV, we used spectrum analysis, which decomposes the heart rate oscillations into frequency bands: low frequency (LF=0.04-0.15Hz), which corresponds mainly to sympathetic modulation; and high frequency (HF=0.15-1.2Hz), corresponding to vagal modulation. RESULTS: Under baseline conditions, the BG showed higher values in LF oscillations, lower values in HF oscillations, and increased LF/HF ratio when compared to the CG. After CPT, the values for HRV in the BG were similar to those observed in the CG during basal recording. Five minutes after nasotracheal suction, the BG showed a decrease in LF and HF oscillations; however, after 40 minutes, the values were similar to those observed after application of CPT. CONCLUSIONS: The CPT and nasotracheal suction, both used for airway clearance, promote improvement in autonomic modulation of HRV in children with acute bronchiolitis. .

Effects of dorsal and lateral decubitus on peak expiratory flow in healthy subjects.

BACKGROUND: One of the measures of the pulmonary function is the peak expiratory flow (PEF) that can be defined as the major flow obtained in an expiratory pressure after a complete inspiration to the level of the total lung capacity. This measure depends on the effort and strength of expiratory muscles, the airway diameter and the lung volume. OBJECTIVE: To compare the results of the peak expiratory flow in healthy male and female obtained in a seated position and dorsal decubitus (DD), right lateral decubitus (RLD) and left lateral decubitus (LLD). METHOD: Thirty young subjects with mean age 22.7 years, healthy and non-smokers were included at the study, 15 of male sex. They did spirometry and IPAQ questionnaire to check the normal pulmonary function and physical activity level. The measures of PEF were performed in four positions, being performed 3 measures in which position, in a random order. Statistical analysis was performed according to Student's t test, with significance level set at 5%. RESULTS: There was a difference between the values obtained in sitting position (481±117.1 L/min) with DD(453.2±116.3 L/min) and RLD (454±112.9 L/min) (p<0.05), however, did not find a significant difference between the sitting position and LLD (469±83 L/min). CONCLUSIONS: Body position affects the values of PEF, with decreasing values in DD and RLD. The LLD can be an alternative to optimize the expiratory flow in situations of constraint to the sitting position.

Physical therapy for airway clearance improves cardiac autonomic modulation in children with acute bronchiolitis.

BACKGROUND: The effects of physical therapy on heart rate variability (HRV), especially in children, are still inconclusive. OBJECTIVE: We investigated the effects of conventional physical therapy (CPT) for airway clearance and nasotracheal suction on the HRV of pediatric patients with acute bronchiolitis. METHOD: 24 children were divided into two groups: control group (CG, n=12) without respiratory diseases and acute bronchiolitis group (BG, n=12). The heart rate was recorded in the BG at four different moments: basal recording (30 minutes), 5 minutes after the CPT (10 minutes), 5 minutes after nasotracheal suction (10 minutes), and 40 minutes after nasotracheal suction (30 minutes). The CG was subjected to the same protocol, except for nasotracheal suction. To assess the HRV, we used spectrum analysis, which decomposes the heart rate oscillations into frequency bands: low frequency (LF=0.04-0.15 Hz), which corresponds mainly to sympathetic modulation; and high frequency (HF=0.15-1.2 Hz), corresponding to vagal modulation. RESULTS: Under baseline conditions, the BG showed higher values in LF oscillations, lower values in HF oscillations, and increased LF/HF ratio when compared to the CG. After CPT, the values for HRV in the BG were similar to those observed in the CG during basal recording. Five minutes after nasotracheal suction, the BG showed a decrease in LF and HF oscillations; however, after 40 minutes, the values were similar to those observed after application of CPT. CONCLUSIONS: The CPT and nasotracheal suction, both used for airway clearance, promote improvement in autonomic modulation of HRV in children with acute bronchiolitis.

Effects of dorsal and lateral decubitus on peak expiratory flow in healthy subjects / Efeitos do posicionamento em decubito dorsal e lateral no pico de fluxo expiratorio em adultos saudaveis

BACKGROUND: One of the measures of the pulmonary function is the peak expiratory flow (PEF) that can be defined as the major flow obtained in an expiratory pressure after a complete inspiration to the level of the total lung capacity. This measure depends on the effort and strength of expiratory muscles, the airway diameter and the lung volume. OBJECTIVE: To compare the results of the peak expiratory flow in healthy male and female obtained in a seated position and dorsal decubitus (DD), right lateral decubitus (RLD) and left lateral decubitus (LLD). METHOD: Thirty young subjects with mean age 22.7 years, healthy and non-smokers were included at the study, 15 of male sex. They did spirometry and IPAQ questionnaire to check the normal pulmonary function and physical activity level. The measures of PEF were performed in four positions, being performed 3 measures in which position, in a random order. Statistical analysis was performed according to Student's t test, with significance level set at 5%. RESULTS: There was a difference between the values obtained in sitting position(481±117.1 L/min) with DD(453.2±116.3 L/min) and RLD (454±112.9 L/min) (p<0.05), however, did not find a significant difference between the sitting position and LLD (469±83 L/min). CONCLUSIONS: Body position affects the values of PEF, with decreasing values in DD and RLD. The LLD can be an alternative to optimize the expiratory flow in situations of constraint to the sitting position. .

CONTEXTUALIZAÇÃO: Pico de fluxo expiratório (PFE) é uma das medidas de função pulmonar definida como o maior fluxo obtido em uma expiração forçada a partir de uma inspiração completa ao nível da capacidade pulmonar total (CPT). Essa medida é dependente do esforço, da força dos músculos expiratórios, do calibre das vias aéreas e do volume pulmonar. OBJETIVO: Comparar os resultados de PFE em homens e mulheres saudáveis, obtidos na posição sentada, com decúbito dorsal (DD), decúbito lateral direito (DLD) e esquerdo (DLE). MÉTODO: Participaram 30 indivíduos, com média de idade de 22,7 anos, saudáveis e não fumantes, sendo 15 do sexo masculino. Todos realizaram espirometria e responderam ao questionário IPAQ para caracterizar a normalidade da função pulmonar e o nível de atividade física. As medidas de PFE foram realizadas nas quatro posições, sendo realizadas três medidas em cada posição, em ordem aleatória. Para análise estatística, foi utilizado o teste t de Student, com nível de significância estabelecido em 5%. RESULTADOS: Houve diferença entre os valores obtidos na posição sentada (481±117, 1 L/min) com o DD (453,2±116,3 L/min) e DLD (454±112,9 L/min) (p<0,05), porém, não encontramos diferença significativa entre as posições sentada e DLE (469±83 L/min). CONCLUSÕES: A posição corporal afeta os valores de PFE, com diminuição dos valores em DD e DLD. O DLE pode ser uma alternativa para otimizar o fluxo expiratório em situações de restrição à posição sentada. .

Low pressure support changes the rapid shallow breathing index (RSBI) in critically ill patients on mechanical ventilation / Baixos níveis de pressão de suporte alteram o índice de respiração rápida e superficial (IRRS) em pacientes graves sob ventilação mecânica

BACKGROUND: The rapid shallow breathing index (RSBI) is the most widely used index within intensive care units as a predictor of the outcome of weaning, but differences in measurement techniques have generated doubts about its predictive value. OBJECTIVE: To investigate the influence of low levels of pressure support (PS) on the RSBI value of ill patients. METHOD: Prospective study including 30 patients on mechanical ventilation (MV) for 72 hours or more, ready for extubation. Prior to extubation, the RSBI was measured with the patient connected to the ventilator (DragerTM Evita XL) and receiving pressure support ventilation (PSV) and 5 cmH2O of positive end expiratory pressure or PEEP (RSBI_MIN) and then disconnected from the VM and connected to a Wright spirometer in which respiratory rate and exhaled tidal volume were recorded for 1 min (RSBI_ESP). Patients were divided into groups according to the outcome: successful extubation group (SG) and failed extubation group (FG). RESULTS: Of the 30 patients, 11 (37%) failed the extubation process. In the within-group comparison (RSBI_MIN versus RSBI_ESP), the values for RSBI_MIN were lower in both groups: SG (34.79±4.67 and 60.95±24.64) and FG (38.64±12.31 and 80.09±20.71; p<0.05). In the between-group comparison, there was no difference in RSBI_MIN (34.79±14.67 and 38.64±12.31), however RSBI_ESP was higher in patients with extubation failure: SG (60.95±24.64) and FG (80.09±20.71; p<0.05). CONCLUSIONS: In critically ill patients on MV for more than 72h, low levels of PS overestimate the RSBI, and the index needs to be measured with the patient breathing spontaneously without the aid of pressure support.

CONTEXTUALIZAÇÃO: O índice de respiração rápida e superficial (IRRS) tem sido o mais utilizado dentro das unidades de terapia intensiva (UTIs) como preditor do resultado do desmame, porém diferenças no método de obtenção têm gerado dúvidas quanto a seu valor preditivo. OBJETIVO: Verificar a influência de baixos níveis de pressão de suporte (PS) no valor do IRRS em pacientes graves. MÉTODO: Estudo prospectivo, incluindo 30 pacientes sob ventilação mecânica (VM) por 72 horas ou mais, prontos para extubação. Anteriormente à extubação, o IRRS foi obtido com o paciente conectado ao ventilador Evita-XL da DragerTM recebendo pressão de suporte ventilatório (PSV) e PEEP=5 cmH2O (IRRS_MIN) e, logo após, desconectado da VM e conectado a um ventilômetro de WrightTM, onde sua frequência respiratória e o volume corrente exalado eram registrados durante 1 minuto (IRRS_ESP). Os pacientes foram divididos de acordo com o desfecho em grupo sucesso extubação (GS) e grupo insucesso extubação (GI). RESULTADOS: Dos 30 pacientes, 11 (37%) falharam no processo de extubação. Na comparação intragrupos (IRRS_MIN x IRRS_ESP), os valores foram menores para o IRRS_MIN em ambos os grupos: GS (34,79±4,67 e 60,95±24,64) e GI (38,64±12,31 e 80,09±20,71) (p<0,05). Na comparação intergrupos não houve diferença entre IRRS_MIN (34,79±14,67 e 38,64±12,31), por outro lado, IRRS_ESP foi maior nos pacientes com falha na extubação: GS (60,95±24,64) e GI (80,09±20,71) (p<0,05). CONCLUSÃO: Em pacientes graves e sob VM acima de 72 horas, níveis mínimos de PS superestimam o IRRS, sendo necessária sua obtenção com o paciente respirando de forma espontânea sem o auxílio de PS.

Low pressure support changes the rapid shallow breathing index (RSBI) in critically ill patients on mechanical ventilation.

BACKGROUND: The rapid shallow breathing index (RSBI) is the most widely used index within intensive care units as a predictor of the outcome of weaning, but differences in measurement techniques have generated doubts about its predictive value. OBJECTIVE: To investigate the influence of low levels of pressure support (PS) on the RSBI value of ill patients. METHOD: Prospective study including 30 patients on mechanical ventilation (MV) for 72 hours or more, ready for extubation. Prior to extubation, the RSBI was measured with the patient connected to the ventilator (DragerTM Evita XL) and receiving pressure support ventilation (PSV) and 5 cmH2O of positive end expiratory pressure or PEEP (RSBI_MIN) and then disconnected from the VM and connected to a Wright spirometer in which respiratory rate and exhaled tidal volume were recorded for 1 min (RSBI_ESP). Patients were divided into groups according to the outcome: successful extubation group (SG) and failed extubation group (FG). RESULTS: Of the 30 patients, 11 (37%) failed the extubation process. In the within-group comparison (RSBI_MIN versus RSBI_ESP), the values for RSBI_MIN were lower in both groups: SG (34.79±4.67 and 60.95±24.64) and FG (38.64±12.31 and 80.09±20.71; p<0.05). In the between-group comparison, there was no difference in RSBI_MIN (34.79±14.67 and 38.64±12.31), however RSBI_ESP was higher in patients with extubation failure: SG (60.95±24.64) and FG (80.09±20.71; p<0.05). CONCLUSIONS: In critically ill patients on MV for more than 72h, low levels of PS overestimate the RSBI, and the index needs to be measured with the patient breathing spontaneously without the aid of pressure support.