Discontinuation of furosemide decreases PaCO(2) in patients with COPD

The effects of diuretic deprescribing in adult patients: A systematic review to inform an evidence-based diuretic deprescribing guideline

In this systematic review, we report on the effects of diuretic deprescribing compared to continued diuretic use. We included clinical studies reporting on outcomes such as mortality, heart failure recurrence, tolerability and feasibility. We assessed risk of bias and certainty of the evidence using the GRADE framework. We included 25 publications from 22 primary studies (15 randomized controlled trials; 7 nonrandomized studies). The mean number of participants in the deprescribing groups was 35, and median/mean age 64 years. In patients with heart failure, there was no clear evidence that diuretic deprescribing was associated with increased mortality compared to diuretic continuation (low certainty evidence). The risk of cardiovascular composite outcomes associated with diuretic deprescribing was inconsistent (studies showing lower risk for diuretic deprescribing, or comparable risk with diuretic continuation; very low certainty evidence). The effect on heart failure recurrence after diuretic deprescribing in patients with diuretics for heart failure, and of hypertension in patients with diuretics for hypertension was inconsistent across the included studies (low certainty evidence). In patients with diuretics for hypertension, diuretic deprescribing was well tolerated (moderate certainty evidence), while in patients with diuretics for heart failure, deprescribing diuretics can result in complaints of peripheral oedema (very low certainty evidence). The overall risk of bias was generally high. In summary, this systematic review suggests that diuretic discontinuation could be a safe and feasible treatment option for carefully selected patients. However, there isa lack of high-quality evidence on its feasibility, safety and tolerability of diuretic deprescribing, warranting further research.

Cardiovascular Diseases in COPD: From Diagnosis and Prevalence to Therapy

Chronic obstructive pulmonary disease (COPD) is considered one of the leading causes of mortality. Cardiovascular comorbidities are diagnosed often in COPD patients, not only because of the common risk factors these two diseases share, but also because of the systemic inflammation which characterizes COPD and has deleterious effects in the cardiovascular system. The comorbid cardiovascular diseases in COPD result in several difficulties in the holistic treatment of these patients and affect outcomes such as morbidity and mortality. Several studies have reported that mortality from cardiovascular causes is common among COPD patients, while the risk for acute cardiovascular events increases during COPD exacerbations and remains high for a long time even after recovery. In this review, we focus on the prevalence of cardiovascular comorbidities in COPD patients, presenting the evidence regarding the interaction of the pathophysiological pathways which characterize each disease. Furthermore, we summarize information regarding the effects of cardiovascular treatment on COPD outcomes and vice versa. Finally, we present the current evidence regarding the impact of cardiovascular comorbidities on exacerbations, quality of life and survival of COPD patients.

Analysis of pathogenesis and drug treatment of chronic obstructive pulmonary disease complicated with cardiovascular disease

Chronic obstructive pulmonary disease (COPD) is a disease characterized by persistent airflow limitation, and is associated with abnormal inflammatory responses in the lungs to cigarette smoke and toxic and harmful gases. Due to the existence of common risk factors, COPD is prone to multiple complications, among which cardiovascular disease (CVD) is the most common. It is currently established that cardiovascular comorbidities increase the risk of exacerbations and mortality from COPD. COPD is also an independent risk factor for CVD, and its specific mechanism is still unclear, which may be related to chronic systemic inflammation, oxidative stress, and vascular dysfunction. There is evidence that chronic inflammation of the airways can lead to destruction of the lung parenchyma and decreased lung function. Inflammatory cells in the airways also generate reactive oxygen species in the lungs, and reactive oxygen species further promote lung inflammation through signal transduction and other pathways. Inflammatory mediators circulate from the lungs to the whole body, causing intravascular dysfunction, promoting the formation and rupture of atherosclerotic plaques, and ultimately leading to the occurrence and development of CVD. This article reviews the pathophysiological mechanisms of COPD complicated by CVD and the effects of common cardiovascular drugs on COPD.

The Coexistence of Chronic Obstructive Pulmonary Disease and Heart Failure

Chronic obstructive pulmonary disease (COPD) is a chronic illness that is widely prevalent within the United States and has been frequently associated with heart failure (HF). COPD is associated with progressive damage and inflammation of the airways leading to airflow obstruction and inadequate gas exchange. HF represents a decline in the normal functioning of the heart resulting in insufficient pumping of blood through the circulatory system. COPD and HF present with similar signs and symptoms with some variation.

There are many specific diagnostic tests and treatment modalities which we use to diagnose COPD and HF, but it becomes an issue when you come across a patient who has both conditions simultaneously. For example, attempting to use an X-ray to diagnose HF in a COPD patient is next to impossible because the results are manipulated by the COPD disease process. This is the case with many other diagnostic tests such as an electrocardiogram (ECG), chest radiography (X-ray), B-type natriuretic peptide (BNP), echocardiogram, cardiac magnetic resonance imaging (CMR), pulmonary function test (PFT), arterial blood gas (ABG), and exercise stress testing.

When a patient has both COPD and HF, it becomes more difficult to treat. Many treatments for HF have negative impacts on COPD patients and vice-versa, whereas some have also shown positive clinical outcomes in both diseases. It is agreeable that treatment has to be patient-centered and it can vary from case to case depending on the severity of the disease. Ultimately, in this review, we discuss COPD and HF and how they interplay in their diagnostic and treatment modalities to gain a better understanding of how to effectively manage patients who have been diagnosed with both conditions.

Treatment of critically ill patients with acute hypercarbic respiratory failure by average volume-assured pressure support mode

OBJECTIVES

Average volume-assured pressure support (AVAPS), a dual mode, delivers a set tidal volume (TV) per kg by adjusting the pressure between upper and lower inspiratory positive airway pressures (IPAP). Thus, ventilation is presumed to be happened effectively by sending a guaranteed TV. This study was aimed to evaluate the effectiveness of AVAPS mode in critically ill patients with acute hypercarbic respiratory failure (HRF) and compare the results with bilevel positive airway pressure-spontaneous/timed (BPAP-S/T) mode.

METHODS

Sixty patients were assigned to BPAP-S/T (n = 29) and AVAPS modes (n = 31). Maximum IPAP was started at 20 cmH₂ O and minimum IPAP was set at 5 cmH₂ O higher than expiratory positive airway pressure (EPAP) in AVAPS mode. IPAP was started at 15 cmH₂ O in BPAP-S/T mode. IPAP levels were titrated up to 30 cmH₂ O during noninvasive mechanic ventilation (NIMV) with a targeted TV of 6-8 mL/kg. Patients were followed for 5 days.

RESULTS

No differences were found in pH, paCO₂ , HCO₃ , TV and EPAP between the two groups when compared separately by days. Maximum IPAP levels were significantly high in AVAPS mode in all times (P < 0.001). The length of stay (LOS) in intensive care unit (ICU) (P = 0.994) and hospital (P = 0.509), hours of NIMV use per day (P = 0.101) and NIMV success rate (P = 0.931) were identical between the two groups. ICU (P = 0.931), hospital (P = 0.800), 6-month (P = 0.919) and 1-year (P = 0.645) mortality rates were also not different between the both groups.

CONCLUSIONS

AVAPS mode had similar efficiency with BPAP-S/T mode regarding the NIMV treatment success in critically ill patients with acute HRF.

Current challenges in managing comorbid heart failure and COPD

INTRODUCTION

Heart failure (HF) with reduced ejection fraction and chronic obstructive pulmonary disease (COPD) frequently coexist, particularly in the elderly. Given their rising prevalence and the contemporary trend to longer life expectancy, overlapping HF-COPD will become a major cause of morbidity and mortality in the next decade. Areas covered: Drawing on current clinical and physiological constructs, the consequences of negative cardiopulmonary interactions on the interpretation of pulmonary function and cardiopulmonary exercise tests in HF-COPD are discussed. Although those interactions may create challenges for the diagnosis and assessment of disease stability, they provide a valuable conceptual framework to rationalize HF-COPD treatment. The impact of COPD or HF on the pharmacological treatment of HF or COPD, respectively, is then comprehensively discussed. Authors finalize by outlining how the non-pharmacological treatment (i.e. rehabilitation and exercise reconditioning) can be tailored to the specific needs of patients with HF-COPD. Expert commentary: Randomized clinical trials testing the efficacy and safety of new medications for HF or COPD should include a sizeable fraction of patients with these coexistent pathologies. Multidisciplinary clinics involving cardiologists and respirologists trained in both diseases (with access to unified cardiorespiratory rehabilitation programs) are paramount to decrease the humanitarian and social burden of HF-COPD.

Acid-base balance, serum electrolytes and need for non-invasive ventilation in patients with hypercapnic acute exacerbation of chronic obstructive pulmonary disease admitted to an internal medicine ward

BACKGROUND

Hypoventilation produces or worsens respiratory acidosis in patients with hypercapnia due to acute exacerbations of chronic obstructive pulmonary disease (AECOPD). In these patients acid-base and hydroelectrolite balance are closely related. Aim of the present study was to evaluate acid-base and hydroelectrolite alterations in these subjects and the effect of non-invasive ventilation and pharmacological treatment.

METHODS

We retrospectively analysed 110 patients consecutively admitted to the Internal Medicine ward of Cava de' Tirreni Hospital for acute exacerbation of hypercapnic chronic obstructive pulmonary disease. On admission all patients received oxygen with a Venturi mask to maintain arterial oxygen saturation at least >90 %, and received appropriate pharmacological treatment. Non-Invasive Ventilation (NIV) was started when, despite optimal therapy, patients had severe dyspnea, increased work of breathing and respiratory acidosis. Based on Arterial Blood Gas (ABG) data, we divided the 110 patients in 3 groups: A = 51 patients with compensated respiratory acidosis; B = 36 patients with respiratory acidosis + metabolic alkalosis; and C = 23 patients with respiratory acidosis + metabolic acidosis. 55 patients received only conventional therapy and 55 had conventional therapy plus NIV.

RESULTS

The use of NIV support was lower in the patients belonging to group B than in those belonging to group A and C (25 %, vs 47 % and 96 % respectively; p < 0.01). A statistically significant association was found between pCO2 values and serum chloride concentrations both in the entire cohort and in the three separate groups.

CONCLUSIONS

Our study shows that in hypercapnic respiratory acidosis due to AECOPD, differently from previous studies, the metabolic alkalosis is not a negative prognostic factor neither determines greater NIV support need, whereas the metabolic acidosis in addition to respiratory acidosis is an unfavourable element, since it determines an increased need of NIV and invasive mechanical ventilation support.

Influence of pulmonary hypertension on survival in advanced lung disease

BACKGROUND

Effects of pulmonary hypertension (PH) in advanced lung disease remain unclear.

METHODS

The United Network for Organ Sharing database was queried from 1987 to 2013 to assess survival lung transplant candidates to determine influence of PH in advanced lung disease. Thresholds included mean pulmonary artery pressure ≥ 25 mmHg (mild PH) and 35 mmHg (severe PH).

RESULTS

Of 12,405 listed possible candidates, 10,158 were used for univariate analysis, 7050 for Kaplan-Meier (KM) function, 6196 for multivariate Cox models, and 5328 (mild PH) and 1910 (severe PH) for propensity score matching (PSM). For mild and severe PH, univariate revealed that PH was associated with survival difference (HR = 1.530, 95% CI 1.416, 1.654, p < 0.001) and (HR = 2.033, 95% CI 1.851, 2.232, p < 0.001), respectively. KM function curves demonstrated a significant difference for mild PH (Log-rank test: Chi square (df = 1): 117.76, p < 0.0001) and severe PH (Log-rank test: Chi square (df = 1): 230.91, p < 0.0001). Multivariate Cox models also found a significant increased risk for death for mild PH (HR = 1.750, 95% CI 1.606, 1.907, p < 0.001) and severe PH (HR = 2.088, 95% CI 1.879, 2.319, p < 0.001). PSM confirmed this increased risk for death for mild PH (HR = 1.695, 95% CI 1.502, 1.914, p < 0.001) and severe PH (HR = 1.976, 95% CI 1.641, 2.379, p < 0.001).

CONCLUSIONS

PH is associated with significant increased risk for death in patients with advanced lung disease.

Effects of gas exchange on acid-base balance

This paper describes the interactions between ventilation and acid-base balance under a variety of conditions including rest, exercise, altitude, pregnancy, and various muscle, respiratory, cardiac, and renal pathologies. We introduce the physicochemical approach to assessing acid-base status and demonstrate how this approach can be used to quantify the origins of acid-base disorders using examples from the literature. The relationships between chemoreceptor and metaboreceptor control of ventilation and acid-base balance summarized here for adults, youth, and in various pathological conditions. There is a dynamic interplay between disturbances in acid-base balance, that is, exercise, that affect ventilation as well as imposed or pathological disturbances of ventilation that affect acid-base balance. Interactions between ventilation and acid-base balance are highlighted for moderate- to high-intensity exercise, altitude, induced acidosis and alkalosis, pregnancy, obesity, and some pathological conditions. In many situations, complete acid-base data are lacking, indicating a need for further research aimed at elucidating mechanistic bases for relationships between alterations in acid-base state and the ventilatory responses.

Mixed acid-base disorders, hydroelectrolyte imbalance and lactate production in hypercapnic respiratory failure: the role of noninvasive ventilation

Background

Hypercapnic Chronic Obstructive Pulmonary Disease (COPD) exacerbation in patients with comorbidities and multidrug therapy is complicated by mixed acid-base, hydro-electrolyte and lactate disorders. Aim of this study was to determine the relationships of these disorders with the requirement for and duration of noninvasive ventilation (NIV) when treating hypercapnic respiratory failure.

Methods

Sixty-seven consecutive patients who were hospitalized for hypercapnic COPD exacerbation had their clinical condition, respiratory function, blood chemistry, arterial blood gases, blood lactate and volemic state assessed. Heart and respiratory rates, pH, PaO₂ and PaCO₂ and blood lactate were checked at the 1st, 2nd, 6th and 24th hours after starting NIV.

Results

Nine patients were transferred to the intensive care unit. NIV was performed in 11/17 (64.7%) mixed respiratory acidosis–metabolic alkalosis, 10/36 (27.8%) respiratory acidosis and 3/5 (60%) mixed respiratory-metabolic acidosis patients (p = 0.026), with durations of 45.1±9.8, 36.2±8.9 and 53.3±4.1 hours, respectively (p = 0.016). The duration of ventilation was associated with higher blood lactate (p<0.001), lower pH (p = 0.016), lower serum sodium (p = 0.014) and lower chloride (p = 0.038). Hyponatremia without hypervolemic hypochloremia occurred in 11 respiratory acidosis patients. Hypovolemic hyponatremia with hypochloremia and hypokalemia occurred in 10 mixed respiratory acidosis–metabolic alkalosis patients, and euvolemic hypochloremia occurred in the other 7 patients with this mixed acid-base disorder.

Conclusions

Mixed acid-base and lactate disorders during hypercapnic COPD exacerbations predict the need for and longer duration of NIV. The combination of mixed acid-base disorders and hydro-electrolyte disturbances should be further investigated.

Cardiac disease in chronic obstructive pulmonary disease

The cardiac manifestations of chronic obstructive pulmonary disease (COPD) are numerous. Impairments of right ventricular dysfunction and pulmonary vascular disease are well known to complicate the clinical course of COPD and correlate inversely with survival. The pathogenesis of pulmonary vascular disease in COPD is likely multifactorial and related to alterations in gas exchange and vascular biology, as well as structural changes of the pulmonary vasculature and mechanical factors. Several modalities currently exist for the assessment of pulmonary vascular disease in COPD, but right heart catheterization remains the gold standard. Although no specific therapy other than oxygen has been generally accepted for the treatment of pulmonary hypertension in this population, there has been renewed interest in specific pulmonary vasodilators. The coexistence of COPD and coronary artery disease occurs frequently. This association is likely related to shared risk factors as well as similar pathogenic mechanisms, such as systemic inflammation. Management strategies for the care of patients with COPD and coronary artery disease are similar to those without COPD, but care must be given to address their respiratory limitations. Arrhythmias occur frequently in patients with COPD, but are rarely fatal and can generally be treated medically. Use of beta-blockers in the management of cardiac disease, while a theoretical concern in patients with increased airway resistance, is generally safe with the use of cardioselective agents.

Elevated Carbon Dioxide Tension as a Predictor of Subsequent Adverse Events in Infants with Bronchopulmonary Dysplasia

Infants with bronchopulmonary dysplasia (BPD) are at risk for numerous complications following discharge from the Neonatal Intensive Care Unit (NICU). Few studies have evaluated risk factors for adverse events (AE). This retrospective study provided an initial evaluation of the use of capillary carbon dioxide (PCO2) tension as a predictor of infants with BPD at increased risk for AE. PCO2 was compared in patients who suffered, or avoided, severe AE, defined as pulmonary hypertension, death, or subsequent reintubation or tracheostomy for respiratory illness. One hundred twelve consecutive patients followed at the BPD clinic were evaluated, and data from 104 subjects were suitable for analysis. Mean PCO2, obtained shortly before or after discharge from NICU, was 47.2 mmHg (range, 31-83). PCO2 was significantly higher in patients who required reintubation and ventilation (54.7 vs. 46.7, p < 0.04). No cutoff value of PCO2 clearly distinguished patients with subsequent AE. PCO2 was not significantly higher in the group of patients who had a severe AE than in the group of patients who did not have a severe AE, but logistic regression showed a significant association between PCO2 and risk of both severe AE (p = 0.018), and readmission to hospital (p = 0.038). An elevated PCO2 is associated with an increased risk of AE, including reintubation, and readmission to hospital, in infants with BPD. Patients with an elevated discharge PCO2 may require closer monitoring during followup. Prospective studies will be needed to confirm these observations.

Iatrogenic-induced dysfunction of the neuromuscular respiratory system

In the presence of respiratory symptoms that are associated with alveolar hypoventilation or a restrictive ventilatory defect and in the absence of parenchymal or pleural abnormalities on the chest radiograph, iatrogenic causes must be evoked, exactly as they are in the presence of interstitial lung disease. In most cases, the anamnestic and clinical contexts provide a strong diagnostic presumption. It is important to establish carefully the mechanism of the observed disorders, using the currently available arsenal of diagnostic tools for clinical and prognostic reasons and from a medicolegal standpoint. It is necessary to evaluate precisely the clinical repercussions of the respiratory neuromuscular abnormality to serve as a basis for follow-up and to discuss therapeutic options in certain cases (eg, nocturnal ventilation to correct nocturnal hypoventilation due to diaphragmatic dysfunction, diaphragm plication to alleviate dyspnea after complete phrenic nerve destruction, phrenic nerve pacing), again in the perspective of medicolegal actions.