Arterial oxygen saturation and breathlessness in patients with chronic obstructive airways disease

Nine patients with chronic obstructive airways disease performed a 6 min self-paced walk (breathing air) on a treadmill and then identical (but operator-controlled) treadmill walks breathing either air or supplemental oxygen sufficient to just prevent arterial oxygen desaturation during the exercise. During the exercises, ventilation was recorded and patients recorded their sensation of breathlessness on a visual analogue scale (VAS) every 30 s. Breathing supplemental oxygen produced a small fall in mean exercise ventilation and a large and consistent reduction in mean exercise breathlessness. In seven patients the VAS scores were higher on air than with supplemental oxygen, at similar levels of ventilation. An analysis of covariance, to control for reduction in ventilation, showed a decrease in mean breathlessness when breathing supplemental oxygen, significant at the 8% level. The reduction in breathlessness produced by preventing exercise desaturation cannot be explained by the decrease in ventilation. This suggests that hypoxia may be a stimulus for breathlessness. The mechanism is unknown.     

Responsiveness to intravenous administration of salbutamol in chronic obstructive pulmonary disease patients with acute respiratory failure

OBJECTIVE: In chronic obstructive pulmonary disease (COPD) patients with acute respiratory failure (ARF), bronchodilating agents administered by inhalation have, in general, little effect on dynamic hyperinflation and concurrent static intrinsic positive end-expiratory pressure (PEEPi,st). Since in COPD the severely obstructed segments of the lung may not be reached by inhaled medication, we reasoned that drug efficiency may be enhanced by intravenous administration of the agent. DESIGN: Physiological study. SETTING: Two four-bed surgical-medical ICUs of a university hospital. PATIENTS: Fourteen COPD patients were studied within 36 h from the onset of ARF. MEASUREMENTS AND RESULTS: Static compliance (Cst,rs), minimal (Rmin,rs) and additional (DeltaRrs) resistance of the respiratory system, and PEEPi,st were measured before and after intravenous administration of salbutamol. All patients had limitation of air flow before and after salbutamol administration. On average, after salbutamol there was a small, though significant, decrease in Rmin,rs (-9%), DeltaRrs (-12%) and PEEPi,st (-8%). CONCLUSION: The changes in resistance and PEEPi,st after intravenous administration of salbutamol were too small to be of clinical significance.     

Respiratory arterial pH and PCO2 oscillations in patients with chronic obstructive airways disease

1. Arterial pH oscillations have been monitored in vivo in patients with well defined chronic obstructive bronchitis, asthma and clinical emphysema. 2. The patients with clinical emphysema were shown to differ from those with chronic obstructive bronchitis on the basis of a number of clinical and physiological criteria. 3. Patients with asthma showed least attenuation of their pH oscillations as a group, in contrast to emphysematous patients who showed most attenuation. In patients with clinical emphysema the attenuation was relatively homogeneous. The patients with chronic obstructive bronchitis showed the full range from normal oscillations (zero attenuation) to zero (complete attenuation). 4. The amplitude and approximate rate of change of upslope of the PaCO2 oscillations in vivo were calculated, from measured pH oscillation amplitudes, using buffer slope values in vitro from Siggaard Anderson [(1962, 1963) Scandinavian Journal of Clinical and Laboratory Investigation, 14, 598-604; 15, 211-217], then dividing the PaCO2 amplitude by half the respiratory period. 5. Mean arterial PCO2 in vitro showed a very strong correlation with the downslope of the pH oscillation in vivo (calculated as for PaCO2 upslope) in patients without clinical emphysema. This correlation would be expected to some extent, owing to the logarithmic relationship of PaCO2 oscillations to pH oscillations. However, the mean arterial PCO2 also showed a very strong correlation with the upslope of the calculated PaCO2 oscillations, again excluding patients with clinical emphysema.     

Testing for reversibility in patients with obstructive airways disease

Asthma and chronic obstructive pulmonary disease (COPD) have many similarities and can occur together in the same patient. Both cause coughing, wheezing and shortness of breath. The major difference between the two is that airflow obstruction is largely reversible in asthma, but in COPD it is largely irreversible.     

Arterial oxygen desaturation during treadmill and bicycle exercise in patients with chronic obstructive airways disease

Nine men with severe chronic obstructive airways disease (COAD), known to desaturate on exercise, performed a 6 min self-paced walk on a treadmill, followed by a bicycle exercise with workloads adjusted to mimic the oxygen consumption achieved on the treadmill. During both exercises, ventilation, oxygen consumption, carbon dioxide production, PaO2, PaCO2, pH and arterial lactate were measured and subjective breathlessness recorded. A reasonable match of oxygen consumption between the two exercises was achieved. In all subjects PaO2 fell to a lower level during treadmill compared with bicycle exercise. Ventilation, carbon dioxide production and arterial lactate were higher during bicycle exercise. Subjective breathlessness was greater during bicycle exercise, in proportion to the higher ventilation on the bicycle. The greater anaerobiosis occurring on the bicycle led to acidosis and an increased ventilation, minimizing the exercise fall in PaO2. Bicycle testing may seriously underestimate exercise desaturation occurring during level walking in patients with severe COAD.     

The haemodynamic effects of propranolol and atenolol medication on dobutamine infusion in patients with coronary artery obstructive disease

We compared the haemodynamic effects of beta-blockers on dobutamine infusion in 60 patients undergoing coronary artery bypass graft surgery. All patients had been taking propranolol (n = 30) or atenolol (n = 30) pre-operatively for at least 1 month. After sternotomy, dobutamine was infused at 2 microg/kg per min, and the dose increased to 4 microg/kg per min and then 8 microg/kg per min, at 15-min intervals. In both groups, dobutamine infusion did not increase the cardiac index or the heart rate, but was associated with an increase in mean arterial pressure, systemic vascular resistance index and mean pulmonary arterial pressure in a dose-dependent manner. The haemodynamic responses to dobutamine infusion were similar in the two groups. We conclude that pre-operative medication with beta-blockers reduced the inotropic and chronotropic effects of dobutamine infusion. There was no difference between the modification produced by propranolol, a non-selective beta-blocker, and that produced by atenolol, a selective beta1-blocker, however.     

Headache in patients with chronic obstructive pulmonary disease: effects of chronic hypoxaemia

The frequency and characteristics of headache in patients with chronic obstructive pulmonary disease (COPD) are not clear and there are only a few studies that have assessed the relationship between chronic hypoxaemia and headache. We performed this study in order to evaluate the frequency and characteristics of headache in COPD patients. A total of 119 patients, with a mean age of 63.4 ± 8.2 years, diagnosed with moderate or severe stable COPD were included in the study. Overall 31.9% of the patients complained of headache and 45.4% were reported to have sleep disorders. There were significant effects of family history of COPD, having other systemic disorders or sleep disorders (snoring, bruxism, restless leg syndrome, etc.) and laboratory data of chronic hypoxaemia and airway obstruction on headache co–morbidity. In conclusion, possibly being a specific subtype of elderly headache, headache in patients with moderate or severe COPD is a common problem and future studies are needed to obtain more knowledge about its pathophysiological and clinical basis.     

对慢性阻塞性肺疾病患者实施自理模式的效果观察

目的：探讨对老年慢性阻塞性肺疾病（C O PD ）患者实施自我护理的方法及效果。方法将92例C O PD患者随机分为观察组和对照组。观察组实施自我护理模式,对照组按常规护理,采用自行设计问卷对2组患者进行调查。结果患者出院时观察组各项评分均优于对照组,也优于入院时。结论实施自我护理模式有助于提高老年慢性阻塞性肺疾病患者的健康水平、生命质量、自理能力     

慢性阻塞性肺疾病患者急性发作期的细菌学分析

目的观察慢性阻塞性肺疾病患者急性发作期(acute exacerbation of chronic obstructive pulmonary disease,AECOPD)的病原菌种类及耐药情况。方法对119例AECOPD患者的痰培养及药敏结果进行统计分析。结果痰标本中分离出共64株致病菌,其中主要为革兰阴性菌(G-)(78.1%),铜绿假单胞菌占28.1%,肺炎克雷伯杆菌占18.8%、大肠埃希菌占14.1%;革兰阳性菌(G+)主要为肺炎链球菌,占6.3%,金黄色葡萄球菌占4.7%,表皮葡萄球菌占3.1%,真菌占7.8%。对革兰阴性杆菌有效的抗生素为亚胺培南、头孢三代、喹诺酮类和阿米卡星。肺炎链球菌对大多数β-内酰胺类抗生素敏感。而对金葡菌最有效的抗生素为万古霉素,其敏感性达100%。结论AECOPD患者呼吸道感然的病原菌以革兰阴性菌为主,因根据药敏结果合理地选用抗生素。     

High-frequency oscillatory ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease

Purpose

High-frequency oscillatory ventilation (HFOV) is usually considered not indicated for treatment of patients with chronic obstructive pulmonary disease (COPD) because of the theoretical risk of air trapping and hyperinflation. The aim of our study was to establish whether HFOV can be safely applied in patients with acute exacerbation of COPD and hypercapnic respiratory failure.

Methods

Ten patients (age, 63-83 years) requiring intensive care treatment who failed on noninvasive ventilation were studied. After initial conventional mechanical ventilation (CMV) of less than 72 hours, all patients were transferred to HFOV for 24 hours and then back to CMV. Arterial blood gases, spirometry, and hemodynamic parameters were repeatedly obtained in all phases of CMV and HFOV at different settings. Regional lung aeration and ventilation were assessed by electrical impedance tomography.

Results

High-frequency oscillatory ventilation was tolerated well; no adverse effects or severe hyperinflation and hemodynamic compromise were observed. Effective CO₂ elimination and oxygenation were achieved. Ventilation was more homogeneously distributed during HFOV than during initial CMV. Higher respiratory system compliance and tidal volume were found during CMV after 24 hours of HFOV.

Conclusions

Our study indicates that short-term HFOV, using lower mean airway pressures than recommended for acute respiratory distress syndrome, appears safe in patients with COPD while securing adequate pulmonary gas exchange.     

呼吸训练队缓解期慢性阻塞性肺病患者肺功能的影响

目的观察呼吸训练对缓解期慢性阻塞性肺病（COPD）患者肺功能的影响。 方法将74例缓解期COPD患者随机分为对照组和治疗组,治疗组进行6个月呼吸训练,包括缩唇呼吸、腹式呼吸、呼吸操,对照组不进行呼吸训练。比较2组治疗前、后肺功能指标。 结果治疗组呼吸训练后肺活量（VC）、用力肺活量（FVC）、第一秒用力呼出量（FEV1）、用力呼气高峰流速（PEFR）、25％肺活量最大呼气流量（V25）增加,残气量（RV）、残气/肺总量％（RV/TLC）减低,与对照组比较,差异有统计学意义（均P<0.05）,与治疗前比较,差异有统计学意义（均P<0.05）。 结论呼吸训练能够改善COPD缓解期患者的肺功能。     

慢性阻塞性肺疾病与急性支气管炎肺功能的对比研究

目的探讨脉冲振荡法(IOS)在慢性阻塞性肺疾病(COPD)、急性支气管炎的检测意义。方法选择100例COPD患者、100例急性支气管炎患者与正常对照者100例行常规肺通气功能及IOS检测。观察VC、FVC、FEV1%、FEV1/FVC、MMEF、VMAX、MVV;Fres、Zrs、R5、R20、R35、X5、Rc、Rp。结果 COPD组与正常组比较,VC、FVC、FEV1%、FEV1/FVC、MMEF、VMAX、MVV明显降低,P<0.05;Zrs、Fres、R5、R35、X5、R20、Rp明显升高,P<0.05。急性支气管炎组与正常组比较,VC、FVC、FEV1%、MVV明显降低,P<0.05;Zrs、Fres、R5、R20、R35、X5、Rp明显升高,P<0.01。COPD组与急性支气管炎组比较,VC、FVC、FEV1%、FEV1/FVC、MMEF、VMAX明显降低,P<0.01;Zrs、Fres、R5、R20、R35、X5、Rp明显升高,P<0.01。结论 COPD存在阻塞性和限制性通气功能障碍,急性支气管炎存在限制性通气功能障碍;COPD、急性支气管炎均存在总气道阻力、周边气道阻力、周边弹性阻力异常升高。COPD气道阻力升高更明显。     

Physiological effects of meals in difficult-to-wean tracheostomised patients with chronic obstructive pulmonary disease

Objectives To evaluate effects of meals in difficult-to-wean tracheostomised patients with chronic obstructive pulmonary diseases during spontaneous breathing or Inspiratory Pressure Support.Design Prospective, crossover, randomised, and physiological study.Setting Weaning centre.Patients Sixteen COPD undergoing either decreasing levels of pressure support or increasing periods of spontaneous breathing.Measurements Each patient underwent monitoring during a 30-min procedure, during and after meals either under pressure support or spontaneous breathing on two consecutive days. Inductance plethysmography was used to monitor respiratory rate and tidal volume. Tidal volume by a flow transducer, arterial oxygen saturation, pulse rate, end-tidal CO2_, and dyspnoea by a visual analogue scale were also assessed.Results ANOVA analysis showed a significant increase under spontaneous breathing for respiratory rate (P<0.001) and for end tidal CO₂ (P<0.03) induced by the meals. Inspiratory pressure support was associated to significantly greater tidal volume (P<0.001), lower respiratory rate (P<0.032), lower respiratory rate/tidal volume (P<0.001), and lower pulse rate (P<0.047) than spontaneous breathing. Under spontaneous breathing but not under pressure support a statistically worsening in meal-induced dispnoea (P<0.001) was found.Conclusions In tracheostomised difficult-to-wean COPD patients: 1) under unassisted breathing, meals may induce an increase in respiratory rate, end-tidal CO₂, and dyspnoea; 2) inspiratory pressure support ventilation prevents dyspnoea from worsening during meals.     

Value of refined care in patients with acute exacerbation of chronic obstructive pulmonary disease

BACKGROUNDUnder physiological conditions, sputum produced during acute exacerbation of chronic obstructive pulmonary disease (AECOPD) can move passively with the cilia in the airway; the sputum is gradually excreted from the depth of the airways through the stimulation of the coughing reflex on the sensory nerve on the surface of the airway. However, when the sputum is thick, the cough is weak, or the tracheal cilia are abnormal, sputum accumulation may occur and affect the exchange of oxygen and carbon dioxide in the lung. Furthermore, the presence of pathogenic microorganisms in sputum may cause or aggravate the symptoms of pulmonary infection in patients, which is the main factor leading to AECOPD. Therefore, promoting effective drainage of sputum and maintaining airway opening are key points requiring clinical attention.AIMTo explore the effect of refined nursing strategies in patients with AECOPD and dysphagia.METHODSWe selected 126 patients with AECOPD and difficulty of expectoration at our hospital, and divided them into a refined care group and a routine care group, with 63 cases each, using a random number table. The two groups of patients were treated with expectorant, anti-infection, oxygen inhalation, and other basic treatment measures; patients in the refined care group were given refined nursing intervention during hospitalization, and the routine care group received conventional nursing intervention. The differences in sputum expectoration, negative pressure suction rate, blood gas parameters, dyspnea score measured through the tool developed by the Medical Research Council (MRC), and quality of life were compared between the two groups. RESULTSAfter 7 d of intervention, the sputum expectoration effect of the refined care group was 62.30%, the effective rate was 31.15%, and the inefficiency rate was 6.56%. The sputum expectoration effect of the routine care group was 44.07%, the effective rate was 42.37%, and the inefficiency rate was 13.56%. The refined care group had better sputum expectoration than the routine care group (P < 0.05). The negative pressure suction rate in the refined care group was significantly lower than that of the routine care group during the treatment (22.95% vs 44.07%, P < 0.05). Before the intervention, the arterial oxygen saturation (PaO₂) and arterial carbon dioxide saturation (PaCO₂) values were not significantly different between the two groups (P > 0.05); the PaO₂ and PaCO₂ values in the refined care group were comparable to those in the routine care group after 7 d of intervention (P > 0.05). Before the intervention, there was no significant difference in the MRC score between the two groups (P > 0.05); the MRC score of the refined care group was lower than that of the routine care group after 7 d of intervention, but the difference was not statistically significant (P > 0.05). Before intervention, there was no significant difference in the symptoms, activities, disease impact, or St. George’s Respiratory questionnaire (SGRQ) total scores between the two groups (P > 0.05). After 7 days of intervention, the symptoms, activities, and total score of SGRQ of the refined care group were higher than those of the routine care group, but the difference was not statistically significant (P > 0.05).CONCLUSIONAECOPD with thick sputum, weak coughing reflex, and abnormal tracheal cilia function will lead to sputum accumulation and affect the exchange of oxygen and carbon dioxide in the lung. Patients with AECOPD who have difficulty expectorating sputum may undergo refined nursing strategies that will promote expectoration, alleviate clinical symptoms, and improve the quality of life.     

Assessing and treating small airways disease in asthma and chronic obstructive pulmonary disease

Asthma and chronic obstructive pulmonary disease (COPD) are chronic inflammatory disorders of the respiratory tract that are characterized by airflow limitation. They are distinct conditions with different causes, structural changes, and immunopathology. The pathophysiology in asthma and COPD involves not only the proximal large airways, but also the distal small airways, and thus the small airways are an important therapeutic target in the treatment of both diseases. The assessment of diseased distal small airways is challenging. Extensive disease can be present in the small airways with little abnormality in conventional pulmonary function tests. Recent advances in imaging technologies have led to better spatial resolution to assess small airways morphology non-invasively. New physiological tests have been developed to detect disease and response to therapy in regional airways. Improving the efficiency of existing aerosolized therapy to direct drug to the appropriate lung regions may improve clinical efficacy. Approaches to target distal lung regions include developing new drug formulations with smaller aerosol particle size or using inhaler devices that emit aerosolized drug at slow inhalation flows. Large studies are needed to determine whether better distal lung deposition leads to improvements in small airways function that are translated into clinically significant patient outcomes.