Slow breathing training reduces resting blood pressure, probably by modifying central autonomic control, but evidence for this is lacking. The pressor response to static handgrip exercise is a measure of autonomic control and the aim of this study was to determine whether slow breathing training modulates the pressor responses to exercise of untrained muscles. Twenty hypertensive patients trained for 8 weeks, 10 with unloaded slow breathing (Unloaded) and 10 breathing against an inspiratory load of 20 cm H2O (Loaded). Ten subjects were untrained controls. Subjects performed a 2 min handgrip pressor test (30 % MVC) pre- and post-training, and blood pressure and heart rate (HR) were measured before the contraction, at the end and following 2 min recovery. Resting systolic (sBP) and HR were reduced as a result of training, as reported previously. After training there was both a smaller pressor response to hand grip exercise and a more rapid recovery of sBP and HR compared to pre-training. There were no changes in the Controls and no differences between the Unloaded and Loaded groups. Combining the two training groups, the sBP response to handgrip exercise after training was reduced by 10 mm Hg (95 % CI: −7, −13) and HR by 5 bpm (95 % CI: −4, −6), all p<0.05. These results are consistent with slow breathing training modifying central mechanisms regulating cardiovascular function.
Ated 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....
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.