Effect of a Conical-PEP Mask on Exercise in Subjects With COPD.

BACKGROUND: Dynamic hyperinflation (DH) is a major pathophysiology of COPD that is directly related to dyspnea and exercise intolerance. Positive expiratory pressure (PEP) might reduce DH and dyspnea during exercise, but at present, there is insufficient evidence to conclude whether it is beneficial for DH, dyspnea, and exercise capacity in COPD. METHODS: A randomized crossover trial with concealed allocation was conducted in 37 moderate to very severe subjects with COPD (34 males, age 66.6 ± 7.4 y, FEV1% of predicted 56.3 ± 13.7). The experimental condition was conical-PEP breathing with a PEP of around 5 cm H2O during a spot marching exercise at a constant speed, inducing 71 ± 9% age-predicted maximum heart rate to symptom limit or 25 min. The control condition was usual breathing. Exercise endurance time and end-exercise symptoms were recorded. Inspiratory capacity (IC) was measured pre-exercise and immediately post exercise. Cardiopulmonary function and breathlessness were monitored throughout the test and after 10 min of recovery. RESULTS: There were no complications or adverse effects during exercise with a conical-PEP mask. Conical-PEP showed longer exercise times than control (median 11.0 [interquartile range 7.7-17.0] min vs 8 [6.0-11.5] min, respectively, P < .001). Most stopped exercising because of breathlessness and leg fatigue. At the end of exercise, IC and breathlessness showed non-significant differences between the conditions, but breathlessness was significantly lower in conical-PEP (median 4 [1.5-5.0] than control 5 [3-6] on Borg scale at isotime for control [8 min]). CONCLUSIONS: Breathing with a 5 cm H2O conical-PEP mask improved exercise time (median 27.1% [0.6-52.9]) in subjects with COPD. The improvement in exercise with the conical-PEP mask was associated with slower development of breathlessness, possibly due to delays in DH development.

The effects of slow loaded breathing training on exercise blood pressure in isolated systolic hypertension.

OBJECTIVES: Slow loaded breathing training has been shown to reduce resting blood pressure (BP) in isolated systolic hypertension (ISH), but it is not known whether this also reduces their exaggerated BP responses to exercise. METHODS: The study was a randomized controlled trial with block allocation stratified by sex. Twenty ISH patients (68 ± 5 yrs, 11 males) were randomized with one group undertaking 8-weeks training with slow loaded breathing (SLB: 25% maximum inspiratory pressure, 6 breaths per minute, 60 breaths every day) or deep breathing control (CON), with 8 weeks follow-up. Outcome measures were home BP and heart rate (HR) with laboratory measures of BP and HR responses to static handgrip and dynamic arm cranking exercise. Data were compared with a two-week run-in baseline. RESULTS: Home systolic BP fell by 22 mmHg (20-23; mean, 95% CI), diastolic BP by 9 mmHg (7-11), and HR by 12 bpm (9-15; all p < .001) as a result of SLB training. Systolic BP at the end of 2-min isometric handgrip was 189 ± 10 mmHg (mean, SD) before training and 157 ± 6 mmHg following SLB training. After 4-min arm exercise, systolic BP, measured at the ankle, was reduced from 243 ± 8 mmHg during the run-in period to 170 ± 15 mmHg after SLB training with no change for CON. The reduction in exercise BP, in both types of exercise, was partly due to a reduction in resting BP and to a smaller increase above resting. Systolic and pulse pressures remained below run-in values 8 weeks after the end of SLB training, and BP response to handgrip exercise remained below run-in values at 4 weeks after SLB training. CONCLUSIONS: SLB not only reduces resting BP in ISH but also the responses to both static and dynamic exercise, potentially reducing the negative aspect of exercise for cardiovascular health.

Incidence and risk factors of pulmonary atelectasis in mechanically ventilated trauma patients in ICU: a prospective study.

AIM: The aim of the study was to obtain information about the incidence and risk factors for pulmonary atelectasis in mechanically ventilated patients in the trauma ICU (TMICU). Pulmonary atelectasis is a common complication leading to serious lung dysfunction in patients in the TMICU and early identification of patients at risk is important for their effective management. METHODS: All trauma patients admitted to the TMICU with mechanical ventilation for more than 1 day were included in a prospective 12-month study. Pulmonary atelectasis was diagnosed from chest radiographs by a critical care doctor and radiologist. RESULTS: A total of 405 trauma patients were identified and data from 338 patients analyzed showing the incidence of pulmonary atelectasis to be 14%. Multivariate analysis revealed significant risk factors to be chest injury with an adjusted odds ratio (AOR) of 102.8, abdominal injury (AOR: 4.6), surgical intervention (AOR: 8.4), comorbidity (AOR: 13.7), Acute Physiology and Chronic Health Evaluation II score (APACHE II) of at least 15 (AOR: 4.8), sedation of at least 7 days (AOR: 7.5) and mechanical ventilation of at least 9 days (AOR: 3.43). Patients with chronic pulmonary disease tended to have higher risk for pulmonary atelectasis (AOR: 8.8). Patients with pulmonary atelectasis had longer stays in TMICU (P < 0.001) and higher mortality (P = 0.013). CONCLUSION: The incidence of pulmonary atelectasis in TMICU in Thailand is comparable with that of the developed world. Pulmonary atelectasis is particularly associated with chest trauma, whereas abdominal injury, APACHE II of at least 15, surgery, comorbidity and prolonged mechanical ventilation are also significant risk factors. Early interventions to prevent or treat pulmonary atelectasis in these patients may improve outcome and shorten their stay in the TMICU and hospital.

Comparison of breathing patterns, pressure, volume, and flow characteristics of three breathing techniques to encourage lung inflation in healthy older people.

Background: It is important to encourage lung inflation to prevent postsurgical pulmonary complications and we compared three breathing techniques that place different emphasis on inspiratory flow and breath-holding. Methods: Fourteen healthy older people (69 ± 3.6 yrs) used diaphragmatic breathing (DB), Triflo II (TF), and a water pressure threshold device (BreatheMAX; BM) in a randomized and balanced crossover design. Outcome measures were inspiratory flow and pressure, inspiratory time (Ti), tidal volume (Vt), and breathing frequency. Results: Inspiratory flow with TF was significantly faster than DB and BM (p < 0.001: 0.96 ± 0.1; 0.43 ± 0.20 and 0.28 ± 0.1 L.s-1, respectively) and pressures greater (p < 0.001: -1.3 ± 0.6, -5.5 ± 1.2 and -2.8 ± 3.6 cm H2O). However, Ti was shorter (TF, 1.16 ± 0.21s; DB, 3.31 ± 0.97 s, p < 0.001; BM, 5.53 ± 1.92 s, p < 0.001), resulting in smaller Vt (TF, 1.12 ± 0.29 L; DB, 1.28 ± 0.29L, p = 0.003; BM, 1.37 ± 0.43L, p = 0.016). Breathing frequency was faster with TF compared to DB and BM (p < 0.001). Conclusions: Substantial lung inflation could be achieved with any of the above-mentioned methods, although Vt was smaller with TF and the high inspiratory flow with this method may not inflate the lower lung. The high pressures and rapid breathing with TF could increase the sense of effort. Trials are needed to determine the clinical value of the different breathing exercises.

The immediate effects of breathing with oscillated inspiratory and expiratory airflows on secretion clearance in intubated patients with cervical spinal cord injury.

STUDY DESIGN: A prospective, randomized crossover trial. OBJECTIVES: To evaluate the efficacy of the combination of incentive spirometry with oscillation (OIS) and positive expiratory pressure with oscillation (OPEP) to promote secretion clearance in intubated patients with cervical spinal cord injury. SETTING: Spinal cord unit, tertiary care hospital, North East Thailand. METHODS: Thirteen intubated patients (C4-7, AIS score C) with secretion retention performed three interventions randomly allocated on consecutive days, a Sham deep breathing, OPEP and OPEP + OIS breathing exercise. Secretions were collected by sterile suction for 3 h before, and 3 h after, each intervention and wet weight recorded. Cardiopulmonary parameters were measured before and after each intervention. RESULTS: The median (IQR) secretion wet weight pre-intervention was 2.61 g (2.21, 3.85) and in the 3 h after Sham there was an increase of 1.97 g (0.6, 3.6). The increase after OPEP was 2.67 g (1.7, 3.9) and after OPEP + OIS, 4.28 g (2.4, 6.7); all the increases being significant (p ≤ 0.007). The clearance after OPEP and OPEP + OIS were both greater than Sham while OPEP + OIS was greater than OPEP (p ≤ 0.019). There were no significant changes in cardiopulmonary measures following any intervention or when compared between interventions. CONCLUSIONS: Deep breathing with an oscillated and humidified air flow in a combination of OIS + OPEP more than doubled secretion clearance and was more effective than OPEP or Sham deep breathing. There were no adverse effects of the procedures which were well tolerated by the patients and may be used to complement existing methods for secretion clearance.

Positive expiratory pressure breathing speeds recovery of postexercise dyspnea in chronic obstructive pulmonary disease.

OBJECTIVES: Faster recovery of postexertional dyspnea might enable chronic obstructive pulmonary disease (COPD) patients to undertake more physical activity. The purpose of this study was to determine whether breathing with a positive expiratory load to reduce dynamic hyperinflation (DH) would hasten recovery. METHODS: Thirteen male COPD patients (59 ± 7 years; Global Initiative for Obstructive Lung Disease Stages II and III) took part in a randomized cross-over trial in which they exercised by self-paced spot marching. Interventions at the end of exercise consisted of six breaths against either a 5-cm H2 O expiratory load (positive expiratory pressure [PEP]) or no load (Sham), with 3-hr rest between interventions. Recovery was followed for the next 10 min. Primary outcome measures were dyspnea during recovery and inspiratory capacity (IC), measured at rest, at the end of exercise and after the intervention; oxygen saturation, end-tidal CO2 , heart rate, and breathing frequency were also monitored. RESULTS: Patients exercised for 5 min reaching a heart rate of 70% age-predicted maximum and developed dyspnea of 3-4 on the Modified Borg CR10 scale. Dyspnea recovered significantly faster after the PEP intervention in all patients, taking 2.8 ± 0.4 min to return to baseline compared with 5.1 ± 0.6 min for Sham (p < 0.01). IC declined at the end of exercise and was improved by PEP (+270 220-460 ml, median, interquartile range) more than Sham (+100, 40-160 ml). However, PEP was equally effective in reducing dyspnea in all patients irrespective of the degree of DH. Changes in oxygen saturation, end-tidal CO2 , heart rate, and breathing frequency were similar in PEP and Sham. CONCLUSIONS: Positive expiratory pressure breathing is an effective means of reducing postexercise dyspnea and DH in COPD. The benefits were not limited to patients with high DH suggesting PEP may be used to speed recovery and increase the volume of exercise during pulmonary rehabilitation sessions and physical activity at home or work.

Design and Function of a New Conical Positive Expiratory Pressure Device to Be Used During Exercise.

BACKGROUND: A flow-dependent conical positive expiratory pressure (PEP) resistor incorporated into a oronasal mask was developed, which might reduce dyspnea and dynamic hyperinflation and increase exercise endurance for patients with COPD. We reported here the flow-pressure relationships and the safety and suitability of the device when used by healthy young and older subjects. METHODS: The flow-pressure relationships were determined for a range of resistors with different orifice diameters and cone lengths. A 1-cm conical-PEP device with a 6- or 7-mm orifice was used during a cycle exercise test (60% heart rate reserve) in 15 young (mean ± SD, 24.3 ± 3.9 y) and 12 older (mean ± SD, 64.4 ± 3.5 y) adults. Cardiopulmonary function and dyspnea were monitored for up to 10 min of exercise. RESULTS: For a given flow, pressure decreased as the cone length and orifice size increased. A 1-cm cone with a 6 mm orifice generated pressures of 5.24 ± 0.17 cm H2O and 18.29 ± 0.34 cm H2O at flows of 0.5 and 0.9 L/s, while for a 7 mm orifice, pressures were 4.88 ± 0.13 cm H2O and 19.14 ± 0.10 cm H2O at flows of 0.5 and 1.1 L/s, such as might occur during exercise. The choice of orifice size for a subject depended on his or her estimated expiratory flow; larger flows required the larger orifice to generate an expiratory pressure of between 5 and 20 cm H2O. Breathing with the conical-PEP device did not affect exercise time, dyspnea, minute ventilation, heart rate, or blood pressure. The SpO2 was slightly lower and PETCO2 was somewhat higher than during control exercise, but the differences were not significant. There were no adverse physiological consequences. CONCLUSIONS: A conical-PEP device of 1-cm length with an orifice of 6 or 7 mm generates effective expiratory pressure for most subjects during exercise. There were no adverse effects in healthy young and older subjects, and the device is suitable for trials with patients with COPD. (ClinicalTrials.gov registration NCT 02788370.).

The effect of slow-loaded breathing training on the blood pressure response to handgrip exercise in patients with isolated systolic hypertension.

Isolated systolic hypertension (ISH) is the most common form of hypertension in older people. It is characterized by increased resting systolic blood pressure (sBP) and increased sBP in response to exercise. It has previously been shown that slow breathing training reduces resting sBP, and the objective of the present study was to determine whether it also reduced the blood pressure response to static handgrip exercise. ISH patients aged between 60 and 74 years were randomly divided into a control group (10 subjects, 4 of which were male) that breathed normally and a trained group (10 subjects, 4 of which were male) that trained daily for 8 weeks by slow breathing against an inspiratory resistance of 18 cmH2O. Before and immediately after training, subjects underwent a 2-min handgrip test (30% max) followed by 2 min of post-exercise circulatory occlusion (PECO) to assess metaboreflex activity. Training reduced sBP by 10.6 mm Hg (95% confidence interval (CI), -16 to -5 mm Hg, P=0.004), but changes were not observed in the control group. The peak exercise sBP was reduced by 23 mm Hg (95% CI, -16 to -31 mm Hg, P<0.001), while the increase in the sBP above resting was reduced by 12.6 mm Hg (95% CI, -6.9 to -18.2 mm Hg, P=0.002). The sBP during PECO was reduced by 8.9 mm Hg (95% CI, -4 to -14 mm Hg, P=0.008), which is indicative of reduced metaboreflex activity; no such change was observed in the control group. The results demonstrate that conventional treatment of older patients with ISH may be improved in two ways by slow breathing training: resting sBP may be reduced by 10 mm Hg, more than can be achieved by conventional pharmacological therapies, while the response to static exercise may be reduced by approximately twice this value.

Breathing Training for Older Patients with Controlled Isolated Systolic Hypertension.

INTRODUCTION: Isolated systolic hypertension (ISH) is very common but difficult to manage with conventional medication. We investigated whether slow breathing training, with and without an inspiratory load, could reduce the resting blood pressure of older well-managed ISH patients. METHODS: Thirty ISH patients (66 ± 4 yr) were randomized into loaded breathing (six breaths per min, 18 cm H2O), unloaded breathing (six breaths per min, no load), or control (normal breathing) groups. After a 2-wk run-in, loaded and unloaded groups trained at home for 30 min every day for 8 wk. Morning home blood pressure and heart rate were measured daily throughout the study. At the end of training, all participants reverted to normal breathing, and blood pressure and heart rate were recorded for a further 8 wk. RESULTS: Compared to the pretraining run-in period, systolic blood pressure was reduced by 18 ± 7 and 11 ± 4 mm Hg for loaded and unloaded groups, respectively (P < 0.001), the reduction being significantly larger for the loaded group (P < 0.05) after 8-wk training. There were no changes in the control group. After the end of training, systolic blood pressure remained below pretraining levels for a further 6 wk for the loaded group but for only 2 wk with the unloaded group. There was a small nonsignificant reduction in diastolic blood pressure with training, as there was for heart rate. Pulse pressures were reduced by 11 ± 5 and 5 ± 6 mm Hg for loaded and unloaded groups, respectively (P < 0.01). CONCLUSION: Slow breathing training, especially with an inspiratory load, is very effective in reducing resting systolic and pulse pressures and could be a valuable adjunct in the management of ISH.

Older Women with Controlled Isolated Systolic Hypertension: Exercise and Blood Pressure.

INTRODUCTION: Exercise is generally regarded as beneficial for health, but the consequent increases in blood pressure might pose a risk for hypertensive subjects. The purpose of this study was to determine blood pressure responses to dynamic exercise and sustained handgrip in patients with isolated systolic hypertension (ISH) who were stable on medication. METHODS: Nineteen female ISH patients (66 ± 5 yr) and 19 age-matched normotensive (NT) female controls undertook a 5-min cycle exercise (60% heart rate reserve [HRR]) and a 2-min handgrip exercise (30% maximum voluntary contraction). Blood pressure responses were measured using an oscillometric cuff, together with heart rate and resting brachial pulse transit times. RESULTS: Systolic blood pressure (SBP) levels after cycle exercise were 194 ± 18 and 153 ± 19 mm Hg for ISH and NT, respectively, with the increase above resting being greater for ISH (P < 0.001), and only small changes were found in diastolic blood pressure (DBP). During handgrip exercise, SBP rose to 168 ± 19 and 140 ± 8 mm Hg for ISH and NT, respectively. The increases above baseline were greater for ISH both during the exercise and postexercise circulatory occlusion (P = 0.017). The increase in DBP levels during exercise and postexercise occlusion were similar in ISH and NT, suggesting little difference in metaboreflex sensitivity. Pulse transit time was shorter for ISH compared with NT (166 ± 6 ms and 242 ± 24 ms, respectively, P < 0.001), indicating stiffer arteries, which would increase SBP but not DBP. CONCLUSION: Despite being well controlled and normotensive control subjects at rest, ISH patients had high SBP responses to both dynamic and static exercises, which may constitute a risk for cardiovascular incidents.