The prognostic variables predictive of mortality in patients with an exacerbation of COPD admitted to the ICU: an integrative review

Prognostic indicators for in-hospital mortality in COPD with acute exacerbation in Thailand: a retrospective cohort study

Background

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a common and deteriorating event leading to in-hospital morbidity and mortality. Identification of predictors for in-hospital mortality of AECOPD patients could aid clinicians in identifying patients with a higher risk of death during their hospitalisation.

Objective

To explore potential prognostic indicators associated with in-hospital mortality of AECOPD patients.

Setting

General medical ward and medical intensive care unit of a university-affiliated tertiary care centre.

Methods

A prognostic factor research was conducted with a retrospective cohort design. All admission records of AECOPD patients between October 2015 and September 2016 were retrieved. Stratified Cox’s regression was used for the primary analysis.

Results

A total of 516 admission records of 358 AECOPD patients were included in this study. The in-hospital mortality rate of the cohort was 1.9 per 100 person-day. From stratified Cox’s proportional hazard regression, the predictors of in-hospital mortality were aged 80 years or more (HR=2.16, 95% CI: 1.26 to 3.72, p=0.005), respiratory failure on admission (HR=2.50, 95% CI: 1.12 to 5.57, p=0.025), body temperature more than 38°C (HR=2.97, 95% CI: 1.61 to 5.51, p=0.001), mean arterial pressure lower than 65 mm Hg (HR=4.01, 95% CI: 1.88 to 8.60, p<0.001), white blood cell count more than 15 x 10⁹/L (HR=3.51, 95% CI: 1.90 to 6.48, p<0.001) and serum creatinine more than 1.5 mg/dL (HR=2.08, 95% CI: 1.17 to 3.70, p=0.013).

Conclusion

Six independent prognostic indicators for in-hospital mortality of AECOPD patients were identified. All of the parameters were readily available in routine practice and can be used as an aid for risk stratification of AECOPD patients.

Predictors of outcome of noninvasive ventilation in severe COPD exacerbation

Background

Noninvasive ventilation (NIV) reduces the rate of endotracheal intubation (ETI) and overall mortality in severe acute exacerbation of COPD (AECOPD) with acute respiratory failure and is increasingly applied in respiratory intermediate care units. However, inadequate patient selection and incorrect management of NIV increase mortality. We aimed to identify factors that predict the outcome of NIV in AECOPD. Also, we looked for factors that influence ventilator settings and duration.

Methods

A prospective cohort study was undertaken in a respiratory intermediate care unit in an academic medical center between 2016 and 2017.

Age, BMI, lung function, arterial pH and pCO2 at admission (t0), at 1–2 h (t1) and 4–6 h (t2) after admission, creatinine clearance, echocardiographic data (that defined left heart dysfunction), mean inspiratory pressure during the first 72 h (mIPAP-72 h) and hours of NIV during the first 72 h (dNIV-72 h) were recorded.

Main outcome was NIV failure (i.e., ETI or in-hospital death). Secondary outcomes were in-hospital mortality, length of stay (LOS), duration of NIV (days), mIPAP-72 h, and dNIV-72 h.

Results

We included 89 patients (45 male, mean age 67.6 years) with AECOPD that required NIV. NIV failure was 12.4%, and in-hospital mortality was 11.2%. NIV failure was correlated with days of NIV, LOS, in-hospital mortality (p < 0.01), and kidney dysfunction (p < 0.05). In-hospital mortality was strongly associated with days of NIV (OR 1.27, 95%CI: 1.07–1.5, p < 0.01) and with FEV1 (p < 0.05). All other investigated parameters (including left heart dysfunction, dNIV-72 h, mIPAP-72 h, pH, etc.) did not influence NIV failure or mortality. dNIV-72 h and days of NIV were independent predictors of LOS (p < 0.01). Regarding the secondary outcomes, left heart dysfunction and pH at 1-2 h independently predicted NIV duration (dNIV-72 h, p < 0.01), while BMI and baseline pCO2 predicted NIV settings (mIPAP-72 h, p < 0.01).

Conclusion

In-hospital mortality and NIV failure were not influenced by BMI, left heart dysfunction, age, nor by arterial blood gas values in the first 6 h of NIV. Patients with severe acidosis and left heart dysfunction required prolonged use of NIV. BMI and pCO2 levels influence the NIV settings in AECOPD regardless of lung function.

Independent factors associate with hospital mortality in patients with acute exacerbation of chronic obstructive pulmonary disease requiring intensive care unit admission: Focusing on the eosinophil-to-neutrophil ratio

Background

Factors associated with hospital mortality are unclear in patients with acute exacerbation of COPD (AECOPD) requiring intensive care unit (ICU) admission. We aimed to characterize these patients and identify factors associated with hospital mortality.

Patients and methods

We used a retrospective observational case-control design and recruited patients between January 2015 and March 2017. Of 146 patients enrolled, 24 (16.4%) died during their hospital stay, while 122 survived.

Results

Multivariate logistic regression analyses revealed factors associated with hospital mortality: age (adjusted odds ratio [AOR] 1.12, 95% CI: 1.03–1.23), C-reactive protein (CRP) level >7.5 mg/dL at the emergency room (AOR 4.52, 95% CI: 1.27–16.04), peak eosinophil-to-neutrophil ratio (ENR)×10² on days 8–14 of treatment (AOR 0.22, 95% CI: 0.08–0.63), and in-hospital complications (AOR 4.23, 95% CI: 1.12–15.98) (all P<0.05). After receiver operating characteristic curve analyses, cutoff level for peak ENR×10² was 0.224. To examine the synergistic effects of CRP level and peak ENR, we divided patients into four groups: (G0, reference group) Peak ENR×10² >0.224 on days 8–14 and initial CRP <7.5 mg/dL; (G1) Peak ENR×10² >0.224 on days 8–14 and initial CRP >7.5 mg/dL; (G2) Peak ENR×10² <0.224 on days 8–14 and initial CRP <7.5 mg/dL; and (G3) Peak ENR×10² <0.224 on days 8–14 and initial CRP >7.5 mg/dL. For G2 and G3 patients, the AOR of mortality was significantly different from that of the reference group (G2: AOR 10.00, P = 0.020; G3: AOR 61.79, P<0.001). The relationship between 28-day mortality and the four groups was statistically significant (log-rank test, P<0.001).

Conclusion

Older age, initial CRP >7.5 mg/dL, peak ENR on days 8–14, and in-hospital complications were associated with hospital mortality in patients with AECOPD requiring ICU admission. Patients with both biomarkers, initial CRP >7.5 mg/dL, and peak ENR×10² <0.224 on days 8–14 of treatment, had an increased risk of hospital mortality.

Assisted ventilation in COPD - association between previous hospitalizations and mortality

BACKGROUND

In general, previous studies have shown an association between prior exacerbations and mortality in COPD, but this association has not been demonstrated in the subpopulation of patients in need of assisted ventilation. We examined whether previous hospitalizations were independently associated with mortality among patients with COPD ventilated for the first time.

PATIENTS AND METHODS

In the Danish National Patient Registry, we established a cohort of patients with COPD ventilated for the first time from 2003 to 2011 and previously medicated for obstructive airway diseases. We assessed the number of hospitalizations for COPD in the preceding year, age, sex, comorbidity, mode of ventilation, survival to discharge, and days to death beyond discharge.

RESULTS

The cohort consisted of 6,656 patients of whom 66% had not been hospitalized for COPD in the previous year, 18% once, 8% twice, and 9% thrice or more. In-hospital mortality was 45%, and of the patients alive at discharge, 11% died within a month and 39% within a year. In multivariate models, adjusted for age, sex, mode of ventilation, and comorbidity, odds ratios for in-hospital death were 1.26 (95% confidence interval [CI]: 1.11-1.44), 1.43 (95% CI: 1.19-1.72), and 1.56 (95% CI: 1.30-1.87) with one, two, and three or more hospitalizations, respectively. Hazard ratios for death after discharge from hospital were 1.32 (95% CI: 1.19-1.46), 1.76 (95% CI: 1.52-2.02), and 2.07 (95% CI: 1.80-2.38) with one, two, and three or more hospitalizations, respectively.

CONCLUSION

Preceding hospitalizations for COPD are associated with in-hospital mortality and after discharge in the subpopulation of patients with COPD with acute exacerbation treated with assisted ventilation for the first time.

Risk factors associated with acute exacerbation of chronic obstructive pulmonary disease in HIV-infected and uninfected patients

OBJECTIVE

To determine the association between HIV infection and other risk factors for acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

DESIGN

Longitudinal, national Veterans Aging Cohort Study including 43 618 HIV-infected and 86 492 uninfected veterans.

METHODS

AECOPD was defined as an inpatient or outpatient COPD ICD-9 diagnosis accompanied by steroid and/or antibiotic prescription within 5 days. We calculated incidence rate ratios (IRR) and 95% confidence intervals (CI) for first AECOPD over 2 years and used Poisson regression models to adjust for risk factors.

RESULTS

Over 234 099 person-years of follow-up, 1428 HIV-infected and 2104 uninfected patients had at least one AECOPD. HIV-infected patients had an increased rate of AECOPD compared with uninfected (18.8 vs. 13.3 per 1000 person-years, P < 0.001). In adjusted models, AECOPD risk was greater in HIV-infected individuals overall (IRR 1.54; 95% CI 1.44-1.65), particularly in those with more severe immune suppression when stratified by CD4 cell count (cells/μl) compared with uninfected (HIV-infected CD4 < 200: IRR 2.30, 95% CI 2.10-2.53, HIV-infected CD4 ≥ 200-349: IRR 1.32, 95% CI 1.15-1.51, HIV-infected CD4 ≥ 350: IRR 0.99, 95% CI 0.88-1.10). HIV infection also modified the association between current smoking and alcohol-related diagnoses with risk for AECOPD such that interaction terms for HIV and current smoking or HIV and alcohol-related diagnoses were each significantly associated with AECOPD.

CONCLUSION

HIV infection, especially with lower CD4 cell count, is an independent risk factor for AECOPD. Enhanced susceptibility to harm from current smoking or unhealthy alcohol use in HIV-infected patients may also contribute to the greater rate of AECOPD.

The association between glucose levels and hospital outcomes in patients with acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Corticosteroids used for chronic obstructive pulmonary disease (COPD) exacerbations can cause hyperglycemia in hospitalized patients, and hyperglycemia may be associated with increased mortality, length of stay (LOS), and re-admissions in these patients.

MATERIALS AND METHODS

We did three retrospective studies using charts from July 2008 through June 2009, January 2006 through December 2010, and October 2010 through March 2011. We collected demographic and clinical information, laboratory results, radiographic results, and information on LOS, mortality, and re-admission.

RESULTS

Glucose levels did not predict outcomes in any of the studied cohorts, after adjustment for covariates in multivariable analysis. The first database included 30 patients admitted to non-intensive care unit (ICU) hospital beds. Six of 20 non-diabetic patients had peak glucoses above 200 mg/dl. Nine of the ten diabetic patients had peak glucoses above 200 mg/dl. The maximum daily corticosteroid dose had no apparent effect on the glucose levels. The second database included 217 patients admitted to ICUs. The initial blood glucose was higher in patients who died than those who survived using bivariate analysis (P = 0.015; odds ratio, OR, 1.01) but not in multivariable analysis. Multivariable logistic regression analysis also demonstrated that glucose levels did not affect LOS. The third database analyzing COPD re-admission rates included 81 patients; the peak glucose levels were not associated with re-admission.

CONCLUSIONS

Our data demonstrate that COPD patients treated with corticosteroids developed significant hyperglycemia, but the increase in blood glucose levels did not correlate with the maximum dose of corticosteroids. Blood glucose levels were not associated with mortality, LOS, or re-admission rates.

How do COPD comorbidities affect ICU outcomes?

Background and aim

Chronic obstructive pulmonary disease (COPD) patients with acute respiratory failure (ARF) frequently require admission to the intensive care unit (ICU) for application of mechanical ventilation (MV). We aimed to determine whether comorbidities and clinical variables present at ICU admission are predictive of ICU mortality.

Methods

A retrospective, observational cohort study was performed in a tertiary teaching hospital’s respiratory ICU using data collected between January 2008 and December 2012. Previously diagnosed COPD patients who were admitted to the ICU with ARF were included. Patients’ demographics, comorbidities, body mass index (BMI), ICU admission data, application of noninvasive and invasive MV (NIV and IMV, respectively), cause of ARF, length of ICU and hospital stay, and mortality were recorded from their files. Patients were grouped according to mortality (survival versus non-survival), and all the variables were compared between the two groups.

Results

During the study period, a total of 1,013 COPD patients (749 male) with a mean age (standard deviation) of 70±10 years met the inclusion criteria. Comorbidities of the non-survival group (female/male, 40/131) were significantly higher compared with the survival group (female/male, 224/618): arrhythmia (24% vs 11%), hypertension (42% vs 34%), coronary artery disease (28% vs 11%), and depression (7% vs 3%) (P<0.001, P<0.035, P<0.001, and P<0.007, respectively). Logistic regression revealed the following mortality risk factors: need of IMV, BMI <20 kg/m², pneumonia, coronary artery disease, arrhythmia, hypertension, chronic hypoxia, and higher acute physiology and chronic health evaluation II (APACHE II) scores. The respective odds ratios, confidence intervals, and P-values for each of these were as follows: 27.7, 15.7–49.0, P<0.001; 6.6, 3.5–412.7, P<0.001; 5.1, 2.9–8.8, P<0.001; 2.9, 1.5–5.6, P<0.001; 2.7, 1.4–5.2, P<0.003; 2.6, 1.5–4.4, P<0.001; 2.2, 1.2–3.9, P<0.008; and 1.1, 1.03–1.11, P<0.001.

Conclusion

Patients with severe COPD and cardiac comorbidities and cachexia should be closely monitored in ICU due to their high risk of ICU mortality.

Intensive Care: Who Benefits?

Intensive care has saved many lives but there are still those patients who are so ill at the time of presentation that the benefit of escalating intensive care support is not clear-cut. To be fair to these patients and the others who can benefit from our services, it is vital that decisions concerning how far organ supporting measures should be pursued are made as reliably and robustly as possible. This review describes some of the prognostic features available at presentation or shortly afterwards, pertaining to five clinical scenarios associated with a perceived poor survival rate (ie, acute-on-chronic liver failure, haematological malignancy, chronic lung disease, cardiac arrest and morbid obesity).

Factors affecting mortality following emergency admission for chronic obstructive pulmonary disease

Background

Chronic obstructive pulmonary disease (COPD) is a major cause of mortality worldwide. Patients with COPD frequently have systemic comorbidities that often require unscheduled hospitalization for exacerbation and deterioration of physical conditions, and can have a poor prognosis. We verified factors affecting patients’ short-term mortality, using a national inpatient database in Japan.

Methods

We retrospectively collected data for COPD patients (age: >40 years) with emergency admission between July 2010 and March 2013, using the Diagnosis Procedure Combination database. We performed multivariate logistic analyses fitted with a generalized estimating equation to assess factors associated with all-cause in-hospital mortality.

Results

A total of 177,207 patients (mean age: 77.5 years; males: 72.9%) were identified. All-cause in-hospital death occurred in 23,614 patients (13.7%). Higher mortality was associated with older age, male sex, lower body mass index, more severe dyspnea, lower level of consciousness, and worse activities of daily life. Higher mortality was also associated with comorbid conditions, including bacterial pneumonia, aspiration pneumonia, interstitial pneumonitis, pulmonary embolism, respiratory failure, lung cancer, heart failure, cerebral infarction, liver cirrhosis, and chronic renal failure.

Conclusions

Our study demonstrated that all-cause in-hospital mortality in patients with COPD who required emergency hospitalization was associated with deteriorated general conditions and comorbidities at admission. Physicians should take into account these prognostic factors to choose better treatment options for COPD patients.

The value of assessment tests in patients with acute exacerbation of chronic obstructive pulmonary disease

The aim of our study was to investigate the chronic obstructive pulmonary disease (COPD) assessment test (CAT), serum copeptin, procalcitonin and C-reactive protein (CRP) levels as potential predictive factors for recurrence of acute exacerbation and all-cause mortality in 6 months of COPD inpatients. One hundred fifty-nine patients who met the inclusion criteria were enrolled and followed up for 6 months. The CAT scores, serum copeptin, procalcitonin and CRP levels were measured on admission and 14 days and 3 months later in all patients. The primary endpoint was recurrence of acute exacerbation in 6 months. The secondary endpoint was all-cause mortality after 6 months. The CAT scores, serum copeptin, procalcitonin and CRP levels were significantly elevated on admission and stabilized at 14 days (P < 0.01). In a univariate logistic regression analysis, CAT scores (odds ratio [OR] = 1.10), forced expiratory volume in 1 second % (OR = 1.01), serum copeptin (OR = 1.32) and CRP levels (OR = 1.01) were significantly related to recurrence of acute exacerbation in 6 months (P < 0.05). In a multivariate logistic regression model, increasing CAT scores (OR = 1.10) and serum copeptin levels (OR = 1.29) were still associated with an increased odds of exacerbation (P < 0.05). In a univariate logistic regression analysis, increasing CAT scores (OR = 1.19), forced expiratory volume in 1 second % (OR = 1.05), serum copeptin levels (OR = 1.44) and hospitalization in the previous years (OR = 1.24) were significant determinants of death over a follow-up period of 6 months (P < 0.05). But only serum copeptin (OR = 1.53) and CAT scores (OR = 1.37) were associated with mortality in multivariate logistic regression analysis. Hence, high CAT scores and serum copeptin levels link with recurrence of acute exacerbation and all-cause mortality during 6 months in patients with acute exacerbation of COPD.

Predicting 1-year mortality rate for patients admitted with an acute exacerbation of chronic obstructive pulmonary disease to an intensive care unit: an opportunity for palliative care

The objective of this study was to develop a model to aid clinicians in better predicting 1-year mortality rate for patients with an acute exacerbation of chronic obstructive pulmonary disease admitted to the medical intensive care unit (ICU) with the goal of earlier initiation of palliative care and end-of-life communications in this patient population. This retrospective cohort study included patients from a medical ICU from April 1, 1995, to November 30, 2009. Data collected from the Acute Physiology and Chronic Health Evaluation III database included demographic characteristics; severity of illness scores; noninvasive and invasive mechanical ventilation time; ICU and hospital length of stay; and ICU, hospital, and 1-year mortality. Statistically significant univariate variables for 1-year mortality were entered into a multivariate model, and the independent variables were used to generate a scoring system to predict 1-year mortality rate. At 1-year follow-up, 295 of 591 patients died (50%). Age and hospital length of stay were identified as independent determinants of mortality at 1 year by using multivariate analysis, and the predictive model developed had an area under the operating curve of 0.68. Bootstrap analysis with 1000 iterations validated the model, age, and hospital length of stay, entered the model 100% of the time (area under the operating curve=0.687; 95% CI, 0.686-0.688). A simple model using age and hospital length of stay may be informative for providers willing to identify patients with chronic obstructive pulmonary disease with high 1-year mortality rate who may benefit from end-of-life communications and from palliative care.