Non Invasive Mechanical Ventilation in Elders with Acute Heart Failure

Abstract

Introduction

Methods

Study design

Study population

Variables And Statistical Analysis

Results

Calvo SG; Padilla LD

Research Article

Austin J Clin Cardiolog. 2015; 2(2): 1040.

Calvo SG¹* and Padilla LD²

¹Respiratory Unit, Hospital King Juan Carlos, Mostoles, Spain

²Respiratory Unit, Hospital Universitario 12 de Octubre, Madrid, Spain

*Corresponding author: Gonzalo Segrelles Calvo, c/Gladiolo s/n; Hospital King Juan Carlos, Mostoles, Madrid, Spain

Received: November 18, 2014; Accepted: September 13, 2015; Published: October 08, 2015

The aim of the study was to confirm the usefulness of Non-Invasive Ventilation (NIV) in elders with multiple comorbidities,admittedfor Respiratory Acidosis (RA) due to Heart Failure (HF), and to determine their survival one year after discharge.

Design: Observational prospective trial made at the Hospital Universitario La Princesa (Madrid) between October of 2009 and December of 2012. We included 42 elderly patients with HF and AR treated with NIV.

Results: 62% were females, with a mean age of 78.2 years. Charlson Index was 3.41 and the mean of prescriptions per day was 5.8. The main complication during admission was cardiovascular disease, and 25% of patients passed away during admission. The most frequentre-admissiondiagnosiswas HF. Global survival was 60%.

Discussion: NIV is a useful treatment for elderly patients with HF and nonintubation orders. The principal factors associated to mortality were: low pH and high PaCO2 at ER, high respiratory rate and previous comorbidities.

Keywords: Heart failure; Noninvasive ventilation; Respiratory acidosis; Elderly; Non-intubation orders

Heart Failure (HF) has an incidence of 10% in patients older than 65 years, reaching a 40% in those older than 80 [1], which translates to be the cause of 75% of hospitalizations in this group [2,3]. HF is more frequent in women, producing a 50-60% of total, according to previous studies [2]. The physiopathology of HF in elders is complex and various factors are involved, related not only to age but also to associated comorbidities [4].

Non-Invasive Ventilation (NIV) is advised in acute HF secondary to Acute Pulmonary Edema (APE), reducing the risk of intubation, as well as improving symptoms and gas exchange parameters [5,6]. NIV is more efficient than oxygen therapy [7] and similar to Continuous Positive Air way Pressure (CPAP) regarding clinical outcomes [8,9]. Further more, latest guidelines recommend the use of either NIV or CPAP for acute HF [10,11].

Now a days, there is not sufficient data concerning the indication of NIV in elderly patients admitted for Acute HF (AHF), considering their multiple comorbidities and performance status limitations. The hypothesis of our study was that NIV is useful in this clinical scenario. The main objective was to determine the benefit (efficiency, utility, suitability) of NIV in elder patients admitted for acute HF causing respiratory acidosis, defined as time to gas exchange normalization, days of hospitalization, complications during treatment, mortality rate, and evolution 1 year after hospital discharge.

Prospective observational study carried out in the Respiratory Care Unit (RCU) of Hospital UniversitarioLa Princesa (HULP), from October of 2009 to December of 2012. The HULP is a tertiary hospital located in Madrid, Spain, which provides health care to an estimated population of 350.000 habitants. Our RCU has 4 beds integrated to the Respiratory Ward, allowing non-invasive monitoring of hemodynamic parameters (blood pressure, heart rate, Respiratory Rate (RR), peripheral pulseoximetry (SpO2) and continuous electrocardiography) and respiratory support by NIV along with mechanical invasive ventilation in selected patients on which a tracheostomy was performed. Specialized nursing care providers and a Respiratory Care physician are in charge of the RCU during morning shifts, whereas a physician assumes its supervision during night shifts and weekends. The entire population of this study were treated with Bi-Level Positive Airway Pressure (BiPAP) in Pressure Support (PS) mode.

Patients admitted to our RCU for HF and respiratory acidosis (pH < 7.35 and PaCO2 >45mmHg), treated with NIV and at least 70 years old were included. HF diagnosis was based on the European Society of Cardiology recommendations [10], while the Chronic Respiratory Obstructive Disease (COPD) diagnosis followed the Spanish Guideline of COPD (GesEPOC) [12]. A “do-not-intubate” indication was considered in the entire population since the following criteria: 1.The patient decided not to be treated by invasive respiratory support through an orotracheal intubation, or had previously stated this wish signing a legal document regarding this matter. 2. The corresponding physician who treated the patient during an acute scenario (Emergency Room (ER), Intensive Care Unit (ICU), Respiratory or Internal Medicine Ward) had not considered the patient as an optimal candidate for invasive respiratory support since a poor prognosis or lacking life performance status were concluded. 3. A legal representative orcare giver manifested their wish to avoid any intensive care measure. The following patients were excluded: 1. Patients admitted to the RCU, however without NIV required. 2. Patients where NIV was initiated in the other units other than the RCU, and after wards were not admitted to the latter. 3. Patients who rejected NIV. The ethics committee of the HULP approved the study, and informed consent was given by all the participants. All data was retrieved from the HULP databases, allowing access to clinical variables in order to complete the 1-year follow up.

The SPSS 15.0 package for Windows (SPSS Inc., Chicago IL) was used for the statistical analysis. Table 1 shows the variables included in the study. Descriptive analysis is presented using parameters such as means, range and Standard Deviation (SD), and qualitative data is shown as absolute numbers and percentages. Normality in the distribution was assessed by the Kolmogorov-Smirnov test. The difference between quantitative variables was analyzed by the t-student test, and qualitative data by the chi-square and Fisher exact. A p-value < 0.05 was considered statistically significant.

Table 1: Recorded data: Baseline characteristics, ER features, and during admission to the RCU.




  
    
    Baseline 
    Emergency Room (ER) 
    Admission 
  
  
    Demographic 
    Age, sex, LADL*, PC^,    smoking habit. 
    
    
  
  
    Clinical 
    COPD features: LTOT/NIV^♩, BODE/BODEx^ref, GesEPOC⁸phenotype,    PFT^γ, thoracic CT^θ and treatment. 
    Referred symptoms by    patients. 
    Complications. 
  
  
    Charlson Index^ref,    previous HF episodes. 
    Vasoactive drugs    instauration. 
    Length of stay. 
  
  
    
    ICU evaluation. 
    ICU evaluation and    admission (invasive mechanical support treatment) 
  
  
    
    Physical examination    features. 
    Deceases (during    admission and 90 days after) 
  
  
    Complementary tests 
    
    ECG♮, X-Ray characteristics 
    
  
  
    Blood tests: complete    blood count, biochemical analysis (kidney function and solutes), NT-proBNP y    C-reactive protein, and arterial blood gases. 
  
  
    LADL*: Limited Activities Of Daily Living. PC^: Primary Caretaker,    LTOT/VMD^♩: Long-Term Oxygen    Therapy/Non Invasive Ventilation, PFT^γ: Pulmonary Function Tests, Thorax TC^θ: Thorax Computerized Tomography, ECG♮: Electrocardiogram.



Table 1:  Recorded data: Baseline characteristics, ER features, and during admission to the RCU.

Table 2: Baseline characteristics.




  
    
    N (%) 
    Mean (SD) 
  
  
    Sex (females) 
    26 (62%) 
    
  
  
    Age (years) 
    
    78.2 (8.3) 
  
  
    Charlson Index 
    
    3.41 (1.75) 
  
  
    Respiratory    comorbidities: 
    30 (71.5%) 
    
  
  
    � COPD 
    16 (38.1%) 
  
  
    � OSA 
    11 (26.2%) 
  
  
    � TB 
    3 (7.2%) 
  
  
    Prescriptions per day 
    
    5.8 (2.1) 
  
  
    Functional status: 
    
    
  
  
    � Independent 
    20 (47.6%) 
  
  
    � Partially dependent 
    14 (33.3%) 
  
  
    � Dependent 
    8 (19%) 
  
  
    Mobility: 
    
    
  
  
    � Walks around 
    12 (54.5%) 
  
  
    � Bed-chair 
    6 (27.2%) 
  
  
    � Immobilized 
    4 (18.1%) 
  
  
    Institutionalized 
    3 (7,1%) 
    
  
  
    Caretaker 
    12 (28.5%) 
    
  
  
    Dyspnea (MRC): 
    
    
  
  
    � Grade III 
    18 (42.8%) 
  
  
    � Grade IV 
    5 (12%) 
  
  
    Home respiratory    therapies: 
    
    
  
  
    � LTOT 
    16 (38%) 
  
  
    � NIV 
    2 (5%)



Table 2:  Baseline characteristics.

LTOT at discharge

HF admissions

COPD admissions

Other causes admissions

During the inclusion period, a total of 320 patients were admitted to the RCU and 42 patients were included for analysis (Figure 1). Out of these 42, 26 were females (62%), with a mean age of 78.2 ± 8.2 years and a Charlson index of 3.4 ± 1.75. The mean of prescriptions per day was 5.8. (Table 2) shows baseline variables. Previous HF was documented in 34 patients (81.5%), all of them being followed on an outpatient clinic (51% in Cardiology ambulatory care clinic). Thirty patients (72%) had been admitted for AHF in the previous year, and 10 of these patients presented RA. Supplementary oxygen therapy was prescribed in 38% of population. NIV was initiated in the ER in 75% of cases (gasometrical evolution is presented in Table 3).

Figure 1: Flowchart of patients included in the study.

    
    
    Figure 1:  Flowchart of patients included in the study.

Table 3: Arterial Blood Gases (ABG) evolution.




  
    
    ER 
    1 hour after NIV 
    24 hours after NIV 
    At discharge 
  
  
    pH 
    7.24 ± 0.08 
    7.29 ± 0.09 
    7.35 ± 0.08 
    7.41 ± 0.034 
  
  
    PaCO₂ (mmHg) 
    83.1 ± 19.1 
    76.7 ± 17.4 
    66 ± 14.2 
    55.2 ± 11.5 
  
  
    PaO₂ (mmHg) 
    59 ± 21.3 
    78.7 ± 18.4 
    69.20 ± 20 
    63.5 ± 10.8 
  
  
    Bicarbonate (mEq/L) 
    34.8 ± 5.3 
    36.7 ± 5.4 
    38.2 ± 5.7 
    34.3 ± 5.8 
  
  
    
  
  
    Data is presented as mean ± SD unless    otherwise specified SD: Standard Deviation.



Table 3:  Arterial Blood Gases (ABG) evolution.

The most frequent complication during admission was acute renal failure (18%), followed after cardiovascular disease: atrial fibrillation (14.8%) and acute myocardial infarction (3.6%). The mortality was of 25% (10 patients). Main differences between deceased patients and those who survived after admissionare summarized in (Table 4). After a 1-year follow-up, main re-admittance diagnosis was AHF (28 patients), followed after COPD exacerbation (12 patients). The 66% of these re-admitted patients presented AR before 3 months after discharge (Table 5). The entire population survival after 1 year was of 60%.

Table 4: Differences between survivors and deceased patients during admission.




  
    
    Deaths 
    Survivors 
    p-value 
  
  
    n = 10 
    n = 32 
  
  
    Age 
    82.1 
    79.7 
    0.123 
  
  
    Sex (female) 
    6 
    20 
    0.382 
  
  
    Charlson Index 
    3.8 (1.92) 
    3.9 (1.84) 
    0.971 
  
  
    COPD 
    5 
    11 
    0.239 
  
  
    FEV₁ 
    24.80% 
    37.30% 
    0.024 
  
  
    % LVEF 
    64.1 
    50.3 
    0.691 
  
  
    LTOT 
    1 patient (14.3%) 
    6 patients (28.6%) 
    0.721 
  
  
    Previous NIV 
    0 
    1 
    0.627 
  
  
    RA previous admissions 
    7 
    3 
    0.003 
  
  
    Limitations: 
    
    
    
  
  
    -Independent 
    2 (20%) 
    18 (90%) 
    0.007 
  
  
    -Partially dependent 
    5 (50%) 
    9 (64.28%) 
    0.255 
  
  
    -Dependent 
    3 (30%) 
    5 (62.5%) 
    0.031 
  
  
    Dyspnea III-IV (MRC) 
    15 
    8 
    0.004 
  
  
    Initial pH 
    7.19 
    7.25 
    0.004 
  
  
    Initial PaCO₂ 
    88.7 
    69.1 
    0.007 
  
  
    Creatinine (mg/dl) 
    1.05 
    1.29 
    0.527 
  
  
    Leucocytes (/mm3) 
    8,975 
    9,675 
    0.288 
  
  
    %Neutrophils 
    70 
    79 
    0.05 
  
  
    C-reactive Protein 
    1.58 
    6.03 
    0.005 
  
  
    MBP*(mmHg) 
    75.2 
    76 
    0.327 
  
  
    RR** (bpm) 
    32 
    27 
    0.071 
  
  
    Temperature (�C) 
    36.2 
    36.4 
    0.875 
  
  
    
     
  
  
    COPD: Chronic Obstructive Respiratory Disease;    FEV₁: Forced Expiratory Volume in 1 second; LVEF: Left Ventricular    Ejection Fraction; LTOT: Long-term oxygen therapy; RA: Respiratory Acidosis;    MRC: Medical Research Council; MBP*: mean blood pressure; RR**: respiratory    rate.



Table 4:  Differences between survivors and deceased patients during admission.

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Citation: Calvo SG and Padilla LD. Non Invasive Mechanical Ventilation in Elders with Acute Heart Failure. Austin J Clin Cardiolog. 2015; 2(2): 1040.Figure 1). ISSN : 2381-9111

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