Noninvasive mechanical ventilation with helmet in patients with exacerbation of chronic obstructive pulmonary disease: a randomized controlled trial

Hypercapnic encephalopathy syndrome: A new frontier for non-invasive ventilation?

To investigate the effect and tolerance of non-invasive ventilation (NIV) with helmet in patients with respiratory failure caused by acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and the effect on improving blood gas, alleviating dyspnea and the occurrence of complications. Patients with AECOPD and respiratory failure admitted to emergency intensive care unit (EICU) and respiratory intensive care unit (RICU) of the First Affiliated Hospital of Zhengzhou University from January 1st, 2018 to May 31st, 2019 were enrolled. After obtaining the informed consent of the patients or their authorized family members, the patients were divided into two groups: the helmet group and the facial mask group by random number table. NIV was carried out by using helmet or facial mask, respectively. During the course of NIV (immediately, 1 hour, 4 hours and at the end of NIV), the tolerance score, blood gas analysis, heart rate (HR), respiratory rate (RR) of patients were monitored, and the incidence of tracheal intubation, in-hospital mortality and complications were observed. Kaplan-Meier survival curve was plotted to analyze the 30-day cumulative survival of the two groups. A total of 82 patients with AECOPD and respiratory failure were included during the study period. After excluding patients with the oxygenation index (PaO2/FiO2) > 200 mmHg (1 mmHg = 0.133 kPa), with tracheal intubation or invasive ventilation, suffering from acute myocardial infarction, severe trauma within 2 weeks, excessive secretion, sputum discharge disorder or refusal to participate in the study, 26 patients were finally enrolled in the analysis, randomly assigned to the helmet group and the facial mask group, with 13 patients in each group. The PaO2/FiO2 after NIV of patients in both groups was increased significantly as compared with that immediately after NIV, without significant difference between the two groups, but the increase in PaO2/FiO2 at the end of NIV compared with immediately after NIV in the helmet group was significantly higher than that in the facial mask group (mmHg: 75.1±73.2 vs. 7.7±86.0, P < 0.05). RR at each time point after NIV in the two groups was lower than that immediately after NIV, especially in the helmet group. There were significant differences between the helmet group and facial mask group at 1 hour, 4 hours, and the end of NIV (times/min: 17.5±4.1 vs. 23.1±6.3 at 1 hour, 16.2±2.5 vs. 20.0±5.5 at 4 hours, 15.5±2.5 vs. 21.2±5.9 at the end of NIV, all P < 0.05). The NIV tolerance score of the helmet group at 4 hours and the end was significantly higher than that of the facial mask group (4 hours: 3.9±0.3 vs. 3.3±0.9, at the end of NIV: 3.8±0.6 vs. 2.9±0.9, both P < 0.05). There was no significant difference in the improvement of pH value, arterial partial pressure of carbon dioxide (PaCO2), or HR between helmet group and facial mask group. The total number of complications (cases: 3 vs. 8) and the nasal skin lesions (cases: 0 vs. 4) in the helmet group were significantly less than those in the facial mask group (both P < 0.05). Only 2 patients in the helmet group received endotracheal intubation, and 1 of them died; 5 patients in the facial mask group received endotracheal intubation, and 3 of them died; there was no significant difference between the two groups (both P > 0.05). The Kaplan-Meier survival curve analysis showed that the cumulative survival rate of 30 days in the helmet group was lower than that in the facial mask group, but the difference was not statistically significant (Log-Rank test: χ2 = 1.278, P = 0.258). NIV with helmet has better comfort for patients with AECOPD combined with respiratory failure, and better effect on improving oxygenation and relieving dyspnea, and its effect on carbon dioxide emissions is not inferior to that of traditional mask NIV.

Objective To identify the factors related to prolonged stay in those patients admitted with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) to hospital. Methods Anumber of 661 patients were selected, all the patients admitted with AECOPD to Shanghai Pudong Hospital, either in the internal medical unit or pneumology department, from 2017 to 2018.The baseline characteristics, AECOPD characteristics and comorbidities were recorded. Results A number of 661 patients were assessed, 76.6% were male, and the mean age were 74.5 years.The mean stay were 11.9 days.24% of all patients required prolonged stay, 2.57% of all patients needed admission to intensive care unit (ICU), 14.67% of all patients were treated with noninvasive mechanical ventilation (NIV). The following factors were significantly associated with length of stay: age, lower hemoglobin count, chronic kidney disease, inpatient department, AECOPD characteristics, need for admission to ICU and the need for NIV, the differences were statistically significant (all P<0.05). Conclusions Prolonged stay in AECOPD primarily related to the unit patients are admitted to, and the need for ICU and NIV. Key words: Length of stay; Intensive care units; Acute exacerbation of chronic obstructive pulmonary disease; Noninvasive mechanical ventilation

Introduction: Recent evidence suggests that, with a well-trained staff, severe exacerbations of chronic obstructive pulmonary disease (COPD) with moderate respiratory acidosis (pH &gt; 7.3) can be successfully treated with noninvasive mechanical ventilation (NIMV) on a general respiratory care ward. We conducted an open prospective study to evaluate the efficacy of this approach on a general medicine ward. Material and methods: This study population consisted in 27 patients admitted to a general medicine ward (median nurse:patient ratio 1:12) December 1, 2004 May 31, 2006 for acute COPD exacerbation with hypercapnic respiratory failure and acidosis (arterial pH &lt; 7.34, PaC02 &gt; 45 mmHg). All received assist-mode NIMV (average 12 h / day) via oronasal masks (inspiratory pressure 10-25 cm H2O, expiratory pressure 4-6 cm H2O) to maintain O2 saturation at 90-95%. Treatment was supervised by an experienced pulmonologist, who had also provided specific training in NIMV for medical and nursing staffs (90-day course followed by periodic refresher sessions). Arterial blood pressure, O2 saturation, and respiratory rate were continuously monitored during NIMV. Based on baseline arterial pH, the COPD was classified as moderate (7.25-7.34) or severe (&lt; 7.25). Results: In patients with moderate and severe COPD, significant improvements were seen in arterial pH after 2 (p &lt; 0.05) and 24 h (p&lt; 0.05) of NIMV and in the PaC02 after 24 hours (p &lt; 0.05). Four (15%) of the 27 patients died during the study hospitalization (in-hospital mortality 15%), in 2 cases due to NIMV failure. For the other 23, mean long-term survival was 14.5 months (95% CI 10.2 to 18.8), and no significant differences were found between the moderate and severe groups. Over half (61%) the patients were alive 1 year after admission. Conclusions: NIMV can be a cost-effective option for management of moderate or severe COPD on a general medicine ward. Its proper use requires: close monitoring of ventilated subjects, optimum staff:patient ratio, well-trained staff dedicated to NIMV, and supervision by a pulmonologist with experience in NIMV. The treatment was effective at improving arterial blood gases in both groups of COPD patients. The severity of the COPD did not significantly affect length of hospital stay, in-hospital mortality, or long-term survival.

Exacerbation of chronic obstructive pulmonary disease (COPD) is one of the frequent causes of acute respiratory failure. In our study, we aimed to compare helmet with face mask in noninvasive mechanical ventilation (NIMV) on patients who had acute respiratory failure because of exacerbation of COPD in intensive care unit (ICU). Thirty patients, taken into ICU for exacerbation of COPD, were included in the study. Patients were divided into two groups as face mask group (Group Y) and helmet group (Group H). Appropriate mechanical ventilation settings were recorded after the starting period and NIMV was applied to patients continuously for two hours with these settings. Respiratory frequency (f), blood gas (PaO(2), PaCO(2), PH) and PaO(2)/FiO(2) values and hemodynamic data of all patients were recorded periodically. Compliance of patients were evaluated with patient tolerance scale (PTS). Duration of stay of the patients in ICU and complications were also noted. Demographic characteristics of patients, mechanical ventilator settings and hemodynamic data of the patients in the two groups were found to be similar (p>0.05). Frequency values measured during NIMV are also similar at all measurement times (p>0.05). It was determined that there was a remarkable decrease in respiratory frequency, in both groups after the application of NIMV (p< 0.001). There was no difference with respect to PaO(2), PH and PaO(2)/FiO(2) values at all measurement times, between groups (p> 0.05). PaCO(2) values in the beginning were similar in both groups but PaCO(2) measured at other measurement times for group H were statistically higher compared to the other group (p< 0.05). PTC score measured at during NIMV in group H were remarkably higher (p< 0.05). Helmet developed as an alternative to face mask has a better patient tolerance and accordingly in increases success rate in NIMV. But it must be keeping mind that the decrease in PaCO(2) value is slow with helmet.

Noninvasive mechanical ventilation (NIMV) is accepted as a life-saving treatment for patients presenting to the emergency department and other acute care settings with severe exacerbations of chronic obstructive pulmonary disease (COPD). It was hypothesized that there is marked national variability in the use of NIMV. Therefore, the use of NIMV for COPD exacerbations in urban centres across Canada was evaluated. All Canadian hospitals affiliated with a university training program were surveyed, and a request for involvement in this survey was posted on the Canadian Society of Respiratory Therapy professional practice listserv. Survey information was received from all 33 sites (100%) that were contacted. Marked differences in the application of NIMV were identified across all regions in Canada, ranging from requiring extensive monitoring in the intensive care unit to application on a general internal medical unit with intermittent noninvasive blood pressure monitoring. There were sites that rarely used NIMV for COPD exacerbations and others where it was routine practice. NIMV is a life-saving treatment for acute exacerbations of COPD. Despite clear clinical evidence, its use has not penetrated throughout all the larger urban hospitals in Canada. This may be more problematic in sites without 24 h respiratory therapy support. There are barriers to the routine application of NIMV that can be overcome using established guidelines and available evidence.

Objective To analyze the risk factors for the failure of noninvasive mechanical ventilation (NIV) in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and to help the clinical risk assessment and decision making. Methods A retrospective case control study was conducted. The patients with AECOPD undergoing NIV admitted to Kaifeng Emergency Center from June 2011 to March 2016 were enrolled, and they were divided into two groups according to whether NIV was successful or not within 12 hours. The nutritional status, blood gas analysis, serum electrolytes, D-dimer, renal function, serum pre-albumin, as well as kinetic vital signs, Glasgow coma scale (GCS) score, expression of respiratory distress, and spontaneous expectoration were recorded. Logistic forward stepwise regression analysis was used to analyze the factors for failure of NIV. Results 122 patients with the initial NIV were enrolled, with NIV failure in 41 patients within 12 hours, accounted for 33.6%. Compared with NIV success group, the percents of respiratory rate ≥ 25 breaths/min (75.6% vs. 17.3%), expectoration disorders (78.0% vs. 19.8%), circulatory disorders (61.0% vs. 18.5%), malnutrition (61.0% vs. 11.1%), decreased serum pre-albumin (58.5% vs. 17.3%), and GCS score < 12 (75.6% vs. 28.4%) in NIV failure group were significantly increased (all P < 0.05). But there were no significant differences in gender, age, body temperature, blood gas analysis, D-dimer, serum creatinine between two groups. It was shown by the results of binary logistic regression analysis that respiratory rate, expectoration disorders, circulatory disorders, malnutrition, serum pre-albumin, and GCS score were the factors of NIV failure [odds ratio (OR) values were 10.879, 6.338, 9.860, 23.273, 8.862, 6.774, and P values were 0.011, 0.038, 0.024, 0.003, 0.015, 0.041, respectively]. It was shown by the results of logistic stepwise regression analysis that respiratory rate ≥ 25 breaths/min, expectoration disorders, circulatory disorders, malnutrition, decreased serum pre-albumin, and GCS score < 12 were independent risk factors of NIV failure (OR values were 6.610, 5.403, 5.138, 8.153, 4.979, 5.100, and P values were 0.007, 0.013, 0.023, 0.007, 0.027, 0.023, respectively). Conclusions The multiple independent risk factors can induce NIV failure within 12 hours in emergency patients with AECOPD, i.e. increased respiratory rate, expectoration dysfunction, circulatory disorders, malnutrition, decreased serum pre-albumin, and decreased GCS score. Emergency physicians should pay attention to these early risk factors in AECOPD patients, which can be taken as correct judgment and guide. Key words: Acute exacerbation of chronic obstructive pulmonary disease; Noninvasive mechanical ventilation; Risk factor

Noninvasive Positive Pressure Ventilation

ABSTRACTLeft ventricular hypertrophy (LVH) is associated with worse outcomes in chronic obstructive pulmonary disease (COPD); however, its role in an acute exacerbation of COPD (AECOPD) has not been reported. This was a retrospective cohort study during 2008–2012 at an academic medical center. AECOPD patients >18 years with available echocardiographic data were included. LVH was defined as LV mass index (LVMI) >95 g/m2 (women) and >115g/m2 (men). Relative wall thickness was used to classify LVH as concentric (>0.42) or eccentric (<0.42). Outcomes included need for and duration of non-invasive ventilation (NIV) and mechanical ventilation (MV), NIV failure, intensive care unit (ICU) and total length of stay (LOS), and in-hospital mortality. Two-tailed p < 0.05 was considered statistically significant. Of 802 patients with AECOPD, 615 patients with 264 (42.9%) having LVH were included. The LVH cohort had higher LVMI (141.1 ± 39.4 g/m2 vs. 79.7 ± 19.1 g/m2; p < 0.001) and lower LV ejection fraction (44.5±21.9% vs. 50.0±21.6%; p ≤ 0.001). The LVH cohort had statistically non-significant longer ICU LOS, and higher NIV and MV use and duration. Of the 264 LVH patients, concentric LVH (198; 75.0%) was predictive of greater NIV use [82 (41.4%) vs. 16 (24.2%), p = 0.01] and duration (1.0 ± 1.9 vs. 0.6 ± 1.4 days, p = 0.01) compared to eccentric LVH. Concentric LVH remained independently associated with NIV use and duration. In-hospital outcomes in patients with AECOPD were comparable in patients with and without LVH. Patients with concentric LVH had higher NIV need and duration in comparison to eccentric LVH.

Noninvasive ventilation (NIV) is beneficial in acute respiratory failure (ARF) caused by chest trauma; however, NIV-related complications affect the efficacy. We evaluated whether NIV with helmet decreases the incidence of complications and improves its effects in a single center. Patients with ARF after chest trauma were randomized to receive NIV with helmet or face mask. The primary outcome was the rate of NIV-related complications. Secondary outcomes were PaO2/FiO2, patient’s tolerance, intubation rate, length of intensive care unit (ICU) stay, and ICU mortality. The trial was terminated early after an interim analysis with 59 patients. The incidence of complications was lower in the helmet group [10% (3/29) vs 43% (13/30), P = 0.004], and PaO2/FiO2s were higher at 1 h and at the end of NIV (253.14 ± 64.74 mmHg vs 216.06 ± 43.86 mmHg, 277.07 ± 84.89 mmHg vs 225.81 ± 63.64 mmHg, P = 0.013 and 0.012) compared with them in face mask group. More patients reported excellent tolerance of the helmet vs face mask after 4 h of NIV [83% (24/29) vs 47% (14/30), P = 0.004] and at the end of NIV [69% (20/29) vs 30% (9/30), P = 0.03]. Differences in intubation rate, ICU stay, and mortality were non-significant (P = 0.612, 0.100, 1.000, respectively). NIV with helmet decreased NIV-related complications, increased PaO2/FiO2, and improved tolerance compared with NIV with face mask in patients with chest trauma.Trial registration: Registered in the Chinese Clinical Trial Registry (ChiCTR1900025915), a WHO International Clinical Trials Registry Platform (http://www.chictr.org.cn/searchprojen.aspx).

PC-FACS

To evaluate causes of noninvasive mechanical ventilation (NIMV) failure. The rate of NIMV failure in respiratory failure due to chronic obstructive pulmonary disease (COPD) exacerbations was reported as 5%-40%. Materials and methods: The necessity of endotracheal intubation was accepted as NIMV failure. The causes of NIMV failure were assessed in 54 patients (45 males; mean age: 67.7 ± 11.0 years) treated with NIMV because of COPD exacerbations and respiratory failure in an intensive care unit (ICU). Results: There was NIMV failure in 20 patients (37.0%). The rates of hospital-acquired pneumonia and in-hospital mortality were higher (P = 0.003 and P = 0.002, respectively) and the duration of ICU stay was longer (P < 0.0001) in patients with NIMV failure. On admission, arterial pH, serum albumin, and Glasgow Coma Scale levels were lower (P = 0.032, P = 0.024, and P = 0.013, respectively) in the NIMV failure group. Arterial pH was lower (P = 0.039) and respiratory rate was higher (P = 0.010) after 1 h, and the PaO2/FiO2 rate was lower (P = 0.017) and respiratory and heart rates were higher (P = 0.002 and P = 0.020, respectively) after 3 h in the NIMV failure group. Conclusion: The present data strongly suggest that baseline and follow-up clinical and arterial blood gas evaluations can give important clues about NIMV failure in COPD exacerbations.

BackgroundResearch is limited in describing the association between admission source and mortality in critically ill patients. Therefore, this study investigated how intensive care units (ICUs) admission source (emergency department (ED) or ward) correlates with mortality rates.MethodsThis retrospective observational cross-sectional study was conducted in a tertiary pulmonology teaching hospital’s ICU from January 1, 2018, to December 31, 2019. Patients were ICU patients admitted for acute respiratory failure. Demographic, comorbidities, diagnoses, APACHE II score, ICU admission (ED or ward), mechanical breathing support (invasive or noninvasive), length of stay, and mortality were recorded. Comparisons of ICU admission sources and mortality factors were established.ResultsA total of 2,173 ICU patients were studied; 1,011 (46%) were admitted from the ED and 1,162 (54%) from the ward. Their mean age was 70 years, and 66% of them were men. Pneumonia was the leading cause of ICU admission at 60% and Chronic Obstructive Pulmonary Disease (COPD) was the most common comorbidity at 54%. When both groups were evaluated in terms of respiratory support, non-invasive mechanical ventilation use was higher in patients admitted from the emergency room (ED: 50% vs. Ward: 35%), invasive mechanical ventilation was more frequently required in patients admitted from the ward compared to those admitted from the emergency department (ED: 17% vs. Ward: 25%). Length of ICU stay (2 vs. 3 days P < 0.001) and ICU mortality (odds ratio: 1.66, 95% confidence interval 1.297–2.124, P < 0.001) were higher in patients admitted from the ward than in patients admitted from the emergency department. In addition, pneumonia patients and those with malignancies, interstitial lung disease, or noninvasive mechanical ventilation (NIV) failure were associated with higher mortality.ConclusionOur study suggests that ward-to-ICU patients had higher mortality rates compared to ED-to-ICU patients. Triage protocols to better identify potentially critically ill patients in the ED may improve outcomes by avoiding delays in care and better assignment of admission location.

In the evolution of patients with chronic obstructive pulmonary disease (COPD), exacerbations occur, especially, in severe stages, determining aggravated respiratory failure and decreased survival. In order to evaluate the implications of COPD exacerbations in patients with second type of chronic respiratory failure and hypercapnic encephalopathy, a prospective observational study was done among 195 COPD in patients of Targu Mures Clinical County Hospital, Romania. Inclusion criteria consisted in severe exacerbations of COPD, complicated by hypercapnia, defined by an increased level of arterial blood gas carbon dioxide (PaCO2) �45 mmHg, suggestive for the second type of respiratory failure. The increased values of PaCO2 ranged between 45 and 112 mmHg among 95 patients. The prevalence of hypercapnia in COPD patients, admitted in hospital for severe exacerbations, was high (n=91/195; 46.66%). The majority of COPD patients (93.4%) were initially hospitalized in the intensive care unit (ICU) department because of hypercapnic encephalopathy. The mortality rate was higher among patients with endotracheal tube insertion than in patients treated by noninvasive mechanical ventilation. High levels of hypercapnia, conscience disorders and respiratory acidosis may be considered factors of severity in COPD exacerbation.

In patients with acute exacerbations of chronic obstructive pulmonary disease, mechanical ventilation is often needed. The rate of weaning failure is high in these patients, and prolonged mechanical ventilation increases intubation-associated complications. To determine whether noninvasive ventilation improves the outcome of weaning from invasive mechanical ventilation. Multicenter, randomized trial. Three respiratory intensive care units. Intubated patients with chronic obstructive pulmonary disease and acute hypercapnic respiratory failure. A T-piece weaning trial was attempted 48 hours after intubation. If this failed, two methods of weaning were compared: 1) extubation and application of noninvasive pressure support ventilation by face mask and 2) invasive pressure support ventilation by an endotracheal tube. Arterial blood gases, duration of mechanical ventilation, time in the intensive care unit, occurrence of nosocomial pneumonia, and survival at 60 days. At admission, all patients had severe hypercapnic respiratory failure (mean pH, 7.18+/-0.06; mean PaCO2, 94.2+/-24.2 mm Hg), sensory impairment, and similar clinical characteristics. At 60 days, 22 of 25 patients (88%) who were ventilated noninvasively were successfully weaned compared with 17 of 25 patients (68%) who were ventilated invasively. The mean duration of mechanical ventilation was 16.6+/-11.8 days for the invasive ventilation group and 10.2+/-6.8 days for the noninvasive ventilation group (P = 0.021). Among patients who received noninvasive ventilation, the probability of survival and weaning during ventilation was higher (P = 0.002) and time in the intensive care unit was shorter (15.1+/-5.4 days compared with 24.0+/-13.7 days for patients who received invasive ventilation; P = 0.005). Survival rates at 60 days differed (92% for patients who received noninvasive ventilation and 72% for patients who received invasive ventilation; P = 0.009). None of the patients weaned noninvasively developed nosocomial pneumonia, whereas 7 patients weaned invasively did. Noninvasive pressure support ventilation during weaning reduces weaning time, shortens the time in the intensive care unit, decreases the incidence of nosocomial pneumonia, and improves 60-day survival rates.