Patterns of chest wall kinematics during volitional pursed-lip breathing in COPD at rest.

1. Patterns of chest wall kinematics during volitional pursed-lip breathing in COPD at rest. Background: Analysis of chest wall kinematics can contribute to identifying the reasons why some patients benefit from pursed-lip breathing (PLB). Material and methods: We evaluated the displacement of the chest wall and its compartments, the rib cage and abdomen, by optoelectronic plethysmography (OEP), during supervised PLB maneuver in 30 patients with mild to severe chronic obstructive pulmonary disease (COPD). Results: OEP showed two different patterns. The first pattern characterized the 19 most severely obstructed and hyperinflated patients in whom PLB decreased end-expiratory volumes of the chest wall and abdomen, and increased end-inspiratory volumes of the chest wall and rib cage. Deflation of the abdomen and inflation of the rib cage contributed to increasing tidal volume of the chest wall. The second pattern characterized 11 patients in whom, compared to the former group, PLB resulted in the following: (i) increased end-expiratory volume of the rib cage and chest wall, (ii) greater increase in end-inspiratory volume of the rib cage and abdomen, and (iii) lower tidal volume of the chest wall. In the patients as a whole changes in end-expiratory chest wall volume were related to change in Borg score (r2=0.5, p<0.00002). Conclusions: OEP helps identify the reasons why patients with COPD may benefit from PLB at rest. Abstract Roberto Bianchi, Francesco Gigliotti, Isabella Romangnoli, Barbara Lanini, Carla Castellani, Barbara Binazzi, LoredanaStendardi, MichelaGrazzini, Giorgio Scano Purpose Thirty COPD patients with moderate to severe airway obstruction and mild to moderate hyperinflation and hypoxemia participated in the study Inclusion Criteria: • Long history of smoking and moderate to severe chronic dyspnea score (MRC >11) • Clinically stable condition, with no exacerbation, or hospital admission in the preceding four weeks • Free from other significant disease potentially contributing to dyspnea. Lung volumes evaluated with subjects in seated position at rest during quiet breathing and PLB. Chest wall kinematics assessed by a noninvasive optoelectronic plethysmography (OEP). Eighty-nine reflecting markers were placed front and back over trunk and were measured with four infrared TV-cameras. Volume of chest wall (VCW) = volumes of the rib cage (VRC) + volume of abdomen (VAB) Material and Methods Two different PLB pattern groups identified: Euvolumics and Hyperinflators. Differences are identified in Table 1. Important clinical differences were associated with the two pattern groups. • Euvolumicswere more severely obstructed (FEV1/VC and FEV1) and hyperinflated (FRC, TLC, RV) at baseline. They appeared to adopt PLB during common activities of the pulmonary rehabilitation program. • Hyperinflators did not use PLB if not specifically requested. Change in VCWee positively correlated with change in Borg score (r2=0.50, p<0.00002). Table 1. Euvolumics vs. Hyperinflators Results Article 1 Influence of spontaneous pursed lips breathing on walking endurance and oxygen saturation in patients with moderate to severe chronic obstructive pulmonary disease1. All 32 patients performed 2 endurance shuttle walking tests in random order. During endurance walking test 1, a mouthpiece was used in order to prevent spontaneous PLB and in during the second test, PLB was used freely. Results: When PLB was used, the patients walked on average 37 seconds (16%) longer (P<.001) than when PLB was prevented. The average drop in oxygen saturation was 1.2% less when PLB was employed. Conclusion: Spontaneous PLB can be a useful technique to increase walking endurance and reduce oxygen saturation during walking in patients with moderate to severe COPD. These results are similar to the euvolumics group in the main article. Article 2 The use of pursed lips breathing in stable chronic obstructive pulmonary disease: a systematic review of the evidence2. Results: 11 articles (4 moderate and 7 low quality). Moderate quality evidence showed that in stable COPD, PLB increased oxygen saturation and tidal volume. It also reduced respiratory rate at rest and time taken to recover to pre-exercise breathlessness levels. Similar to the previous two articles referenced, not all patients with COPD respond equally to PLB: those with moderate to severe COPD are most likely to benefit. References 1. Faager G., Stahle A., Larsen FF… Article 2 Influence of spontaneous pursed lips breathing on walking endurance and oxygen saturation in patients with moderate to severe chronic obstructive pulmonary disease. Clinical Rehabilitation. 2008; 22: 675-683. 2. Roberts SE., Stern M., Schreuder FM., Watson T. The use of pursed lips breathing in stable chronic obstructive pulmonary disease: a systematic review of the evidence. Physical Therapy Reviews. 2009; 14 (4): 240-246 Presented by: Jillian Redlinger Summary Purpose: The purpose was to answer the question: do changes in operational chest wall volumes help identify the reason for dyspnea relief with PLB in patients with COPD? We hypothesized that an increase in tidal volume of the chest wall promoted by PLB at the exclusive expense of tidal volume of the rib cage would not be associated with dyspnea relief in COPD patients. OEP analysis of VCW helps identify the reason for the benefit of PLB maneuver in severely obstructed COPD patients. PLB is a technique that can be used with patients with COPD at rest in order to decrease dyspnea, but PLB is not effective with every COPD patient at decreasing dyspnea. Those patients with moderate to severe COPD benefit from PLB more than those with a mild COPD. Below in figures 1 and 2, the closed symbols represent end-expiratory volume and open symbols represent end-inspiratory volume. Figure 1. Euvolumics Pursed lip breathing is a clinically significant technique for many patients with COPD. PLB can help slower rate of breathing and decrease feelings of breathlessness. All three articles agreed that this breathing technique is more beneficial in patients with moderate to severe COPD. A downfall to research surrounding PLB in COPD patients is that no high-quality evidence is available. Figure 2. Hyperinflators The most severely affected patients who deflate the chest wall during volitional PLB reported improvement in their sensation of breathlessness. This was not the case with the hyperinflators during PLB. The major difference between the two PLB patterns was the ability of euvolumics to decrease VCWee by decreasing VAbee, while limiting the increase in VRCei. By using PLB, COPD patients breathe larger tidal volumes which correlate with symptomatic relief of dyspnea in some COPD patients The greater VTCW was obtained through increased abdominal contribution in euvolumics as compared with hyperinflators. Pursed-lip breathing (PLB) performed as nasal inspiration followed by expiratory blowing against partially closed lips is a breathing retraining strategy employed by patients with chronic obstructive pulmonary disease (COPD). PLB has been shown to relieve dyspnea by promoting slower and deeper breathing in some COPD patients. An increase in tidal volume obtained from decreasing end-expiratory volume of the abdomen has been shown to lesson the feeling of breathlessness, but an increase in tidal volume due to increase in rib cage inspiratory pressure does not attenuate the dyspnea. Results (cont.) Clinical Significance Conclusion Introduction Discussion