Long‐term non‐invasive ventilation to manage persistent ventilatory failure after COPD exacerbation

Background and objective: Patients with ventilatory failure at discharge from hospital following an exacerbation of COPD (ECOPD) have increased work of breathing and reduced inspiratory muscle strength compared with those with a normal arterial carbon dioxide tension (PaCO₂). They also have a significantly worse prognosis. Long‐term non‐invasive positive pressure ventilation (NIPPV) may offer a treatment strategy but benefits have not been established. Methods: We examined the outcomes of 35 patients, with a PaCO₂ >7.5 kPa and normal pH, following hospital admission with an ECOPD. Patients were initiated on long‐term NIPPV. Our aims were to establish if NIPPV was tolerated and to describe the effects on ventilatory parameters. Results: Daytime arterial blood gases and nocturnal ventilatory parameters improved significantly on NIPPV. Diurnal PaO₂, self‐ventilating, rose from (mean (SD)) 7.3 (1.8) to 8.1 (0.9) kPa (P = 0.005) and PaCO₂ fell from 8.8 (1.3) to 7.3 (0.8) kPa (P ≤ 0.001). Mean overnight oxygen saturations increased from 82% (7%) to 89% (2%) (P ≤ 0.001) and mean overnight transcutaneous carbon dioxide fell from 7.6 (1.3) to 5.6 (1.7) kPa (P ≤ 0.001). Similar changes were seen in a group of stable COPD patients, who initiated NIPPV without a preceding exacerbation, suggesting improvements were not solely due to recovery from exacerbation. Acceptance (89%) and compliance (8.4 (3.5) h/day) with domiciliary treatment were good. Median survival was 28.6 months (95% CI: 10.9–46.8). Conclusions: NIPPV was well tolerated in this group and appears to improve ventilation. Our preliminary data support further investigation of NIPPV in patients who remain hypercapnic after hospital admission with ECOPD.     

Five‐year outcome in COPD patients after their first episode of acute exacerbation treated with non‐invasive ventilation

Background and objective: Little is known about long‐term survival of patients surviving the first episode of type II respiratory failure requiring non‐invasive ventilation (NIV). We aimed to determine the 1‐, 2‐ and 5‐year survival, cause of death and potential prognostic indicators in this patient cohort. Methods: We retrospectively identified 100 sequential COPD patients (mean age 70, mean FEV₁ 37% predicted) treated with NIV for the first time. Mortality and data on hospital morbidity and potential prognostic factors were collected from patient records and a State Health Data Linkage Service. Results: Survival at 1, 2 and 5 years was 72%, 52% and 26%, respectively. Respiratory failure secondary to COPD was the commonest cause of death (56.8%), followed by cardiovascular events (25.7%). Readmission rate at 1 year was 60% for those who survived 2 years or more and 52% for those deceased within 2 years. Recurrent respiratory failure requiring NIV was observed in 31% of the cohort. Only advance age (P = 0.04), BMI (P = 0.014) and prior domiciliary oxygen use (P = 0.03) correlated with death within 5 years. Severity of respiratory failure did not correlate with mortality. Conclusions: The 2‐ and 5‐year mortality rates for patients with COPD surviving their first episode of respiratory failure requiring NIV are high. Physiological measures of the severity of respiratory failure at presentation do not predict subsequent survival and nor does the time interval between first and second admissions requiring NIV. Age, BMI and prior need for domiciliary oxygen are the main predictors of mortality at 5 years.     

Prognostic value of different scoring models in patients with multiple organ dysfunction syndrome associated with acute COPD exacerbation

Background and objective

Chronic obstructive pulmonary disease (COPD) represents an increasing healthcare concern as a leading cause of morbidity and mortality worldwide. Our objective was to predict the outcome of COPD patients associated with multiple organ dysfunction syndrome (MODS) by scoring models.

Methods

A retrospective study was performed on severe COPD patients within 24 hours of the onset of MODS. The Acute Physiology and Chronic Health Evaluation (APACHE) II, APACHE III, Multiple Organ Dysfunction Score (MODS), Simplified Acute Physiology Score II (SAPS II), and Sepsis-related Organ Failure Assessment (SOFA) scores were calculated for patients.

Results

A total of 153 elderly patients were recruited. Compared to 30-day survivors, the number of failing organs and all of the scoring models were significantly higher in 30-day non-survivors. The SOFA showed the highest sensitivity and area under the curve (AUC) for predicting the prognosis of patients with MODS induced by acute exacerbation of COPD. The results of logistic regression indicated that factors that were correlated with the prognosis of COPD included the exacerbation history, SOFA score, number of failing organs, and duration of ICU stay. The value of exacerbation frequency for predicting the outcome of COPD was excellent (AUC: 0.892), with a sensitivity of 0.851 and a specificity of 0.797.

Conclusions

The SOFA score, determined at the onset of MODS in elderly patients with COPD, was a reliable predictor of the prognosis. The exacerbation frequency, number of failing organs, and the SOFA score were risk factors of a poor prognosis, and the exacerbation frequency could also effectively predict the outcome of COPD.     

慢性阻塞性肺疾病患者急性加重期瘦素的表达及作用

目的了解慢性阻塞性肺疾病(COPD)患者炎症发生过程中血清瘦素(leptin)的表达、变化及其与缺氧、CO2潴留、气道阻力的关系。方法选择2002-05～2003-05广州市红十字会医院呼吸科住院COPD患者56例,按病程分为:急性加重期、临床稳定期。在不同时期测定leptin、促红细胞生成素(EPO)、C反应蛋白(CRP)、血清白蛋白(ALB)、动脉血气分析指标,并检测肺功能指标,计算体重指数(BMI)、呼吸频率(R)。选择同期正常对照组20例。结果急性加重期leptin、CRP、ALB、动脉血pH值、PaO2、PaCO2、动脉血氧饱和度(SaO2)、R与临床稳定期比较差异有统计学意义(P<0.01)。急性加重期leptin质量浓度与EPO、ALB、动脉血pH值负相关。与CRP、PaCO2、R、BMI正相关,与肺功能指标中的呼吸总阻抗、总气道阻力、中心气道阻力、中心阻力正相关,与1秒用力呼气容积、20Hz振荡频率时弹性阻力和惯性阻力之和呈负相关。临床稳定期leptin、BMI与正常对照组比较显著降低(P均<0.01)。结论COPD患者急性加重期leptin明显升高,可作为急性加重期的炎性标志物。leptin是导致COPD患者反复感染的危险因素。     

The effects of hypoxia and hypercapnia on renal and heart function,haemodynamics and plasma hormone levels in stable COPD patients*

Background: Fluid retention with oedema is an important clinical problem in advanced chronic obstructive pulmonary disease (COPD). Objective: The aim of this study was to investigate cardiovascular, hormonal, renal and pulmonary function data and their possible relation to fluid retention in COPD. Methods: The study group consisted of 25 stable outpatients with COPD. The presence of oedema was assessed by clinical examination and the intake of diuretics was recorded. Glomerular filtration rate (GFR) and the renal blood flow (RBF) were measured. Lung function was assessed with standard spirometry. Cardiac function and haemodynamic variables were studied using echocardiography and equilibrium radionucleotide angiography. The plasma levels of noradrenaline, plasma renin activity, angiotensin II, aldosterone, atrial natriuretic peptide, brain natriuretic peptide and antidiuretic hormone were measured. Results: Systolic and diastolic cardiac functions were found to be well preserved in the patients. Hypercapnia and impaired lung function, but not hypoxia, were clearly associated with oedema/intake of diuretics, low diuresis, low GFR, low RBF and high renal vascular resistance. These effects had no significant relationship to central haemodynamics or the measured plasma hormone levels. Conclusions: In stable COPD, renal fluid retention and oedema are enhanced by hypercapnia‐induced renal vasoconstriction and antidiuresis. In contrast to some earlier reports, this effect does not seem to be mediated via the central haemodynamic reflex systems or the measured plasma hormones. In addition, hypoxia had no significant effect on fluid retention in this group of patients. Please cite this paper as: Hemlin M, Ljungman S, Carlson J, Maljukanovic S, Mobini R, Bech‐Hanssen O and Skoogh B‐E. The effects of hypoxia and hypercapnia on renal and heart function, haemodynamics and plasma hormone levels in stable COPD patients. The Clinical Respiratory Journal 2007; 1:80–90.