Respiratory physiotherapy can increase lower esophageal sphincter pressure in GERD patients

Background: Inspiratory muscle training (IMT) has been shown to increase diaphragm thickness. We evaluated the effect of IMT on mid-respiratory pressure (MRP) in patients with gastroesophageal reflux disease (GERD) and hypotensive lower esophageal sphincter (LES), and compared the results with a sham group. Methods: Twenty consecutive patients (progressive loading group) and 9 controls (sham group) were included. All patients had end expiratory pressure (EEP) between 5 and 10 mmHg, underwent esophageal manometry and pulmonary function tests before and after 8 weeks of training, and used a threshold IMT twice daily. The threshold IMT was set at 30% of the maximal inspiratory pressure for the progressive loading group; while, the threshold for sham-treated patients was set at 7 cmH(2)O for the whole period. Results: There was an increase in MRP in 15 (75%) patients in the progressive loading group, with an average gain of 46.6% (p<0.01), and in six (66%) patients in the sham group with a mean increase of 26.2% (p<0.01). However, there was no significant difference between the groups (p = 0.507). The EEP also increased compared with measurements before training (p<0.01), but it did not differ between groups (p = 0.727). Conclusion: IMT increased LES pressure in patients with GERD, in both the treatment and sham groups, after an eight-week program. Although there was no statistically significant difference between groups, suggesting the pressure increase in LES occurs regardless of the resistance load of the threshold IMT. These findings need to be confirmed in further studies with a larger sample. Registration number: 0922/09. (C) 2012 Elsevier Ltd. All rights reserved.

The effect of acute magnesium loading on the maximal exercise performance of stable chronic obstructive pulmonary disease patients

OBJECTIVE: The potential influence of magnesium on exercise performance is a subject of increasing interest. Magnesium has been shown to have bronchodilatatory properties in asthma and chronic obstructive pulmonary disease patients. The aim of this study was to investigate the effects of acute magnesium IV loading on the aerobic exercise performance of stable chronic obstructive pulmonary disease patients. METHODS: Twenty male chronic obstructive pulmonary disease patients (66.2 +/- 8.3 years old, FEV1: 49.3 +/- 19.8%) received an IV infusion of 2 g of either magnesium sulfate or saline on two randomly assigned occasions approximately two days apart. Spirometry was performed both before and 45 minutes after the infusions. A symptom-limited incremental maximal cardiopulmonary test was performed on a cycle ergometer at approximately 100 minutes after the end of the infusion. ClinicalTrials.gov: NCT00500864 RESULTS: Magnesium infusion was associated with significant reductions in the functional residual capacity (-0.41 l) and residual volume (-0.47 l), the mean arterial blood pressure (-5.6 mmHg) and the cardiac double product (734.8 mmHg.bpm) at rest. Magnesium treatment led to significant increases in the maximal load reached (+8 w) and the respiratory exchange ratio (0.06) at peak exercise. The subgroup of patients who showed increases in the work load equal to or greater than 5 w also exhibited significantly greater improvements in inspiratory capacity (0.29 l). CONCLUSIONS: The acute IV loading of magnesium promotes a reduction in static lung hyperinflation and improves the exercise performance in stable chronic obstructive pulmonary disease patients. Improvements in respiratory mechanics appear to be responsible for the latter finding.

Goal-directed fluid management based on pulse pressure variation monitoring during high-risk surgery: a pilot randomized controlled trial

Abstract Introduction Several studies have shown that maximizing stroke volume (or increasing it until a plateau is reached) by volume loading during high-risk surgery may improve post-operative outcome. This goal could be achieved simply by minimizing the variation in arterial pulse pressure (ΔPP) induced by mechanical ventilation. We tested this hypothesis in a prospective, randomized, single-centre study. The primary endpoint was the length of postoperative stay in hospital. Methods Thirty-three patients undergoing high-risk surgery were randomized either to a control group (group C, n = 16) or to an intervention group (group I, n = 17). In group I, ΔPP was continuously monitored during surgery by a multiparameter bedside monitor and minimized to 10% or less by volume loading. Results Both groups were comparable in terms of demographic data, American Society of Anesthesiology score, type, and duration of surgery. During surgery, group I received more fluid than group C (4,618 ± 1,557 versus 1,694 ± 705 ml (mean ± SD), P < 0.0001), and ΔPP decreased from 22 ± 75 to 9 ± 1% (P < 0.05) in group I. The median duration of postoperative stay in hospital (7 versus 17 days, P < 0.01) was lower in group I than in group C. The number of postoperative complications per patient (1.4 ± 2.1 versus 3.9 ± 2.8, P < 0.05), as well as the median duration of mechanical ventilation (1 versus 5 days, P < 0.05) and stay in the intensive care unit (3 versus 9 days, P < 0.01) was also lower in group I. Conclusion Monitoring and minimizing ΔPP by volume loading during high-risk surgery improves postoperative outcome and decreases the length of stay in hospital. Trial registration NCT00479011

Effects of specimen geometry and loading mode on crack growth resistance curves of a high-strength pipeline girth weld

This work presents an investigation of the ductile tearing properties for a girth weld made of an API 5L X80 pipeline steel using experimentally measured crack growth resistance curves. Use of these materials is motivated by the increasing demand in the number of applications for manufacturing high strength pipes for the oil and gas industry including marine applications and steel catenary risers. Testing of the pipeline girth welds employed side-grooved, clamped SE(T) specimens and shallow crack bend SE(B) specimens with a weld centerline notch to determine the crack growth resistance curves based upon the unloading compliance (UC) method using the single specimen technique. Recently developed compliance functions and η-factors applicable for SE(T) and SE(B) fracture specimens with homogeneous material and overmatched welds are introduced to determine crack growth resistance data from laboratory measurements of load-displacement records.