Severe Acute Hypoxemic Respiratory Failure Research Articles

High-flow nasal cannula oxygen therapy to treat patients with hypoxemic acute respiratory failure consequent to SARS-CoV-2 infection

This observational study aims to assess the outcome and safety of O2-therapy by high-flow nasal cannula (HFNC) in 28 consecutive patients with severe hypoxemic acute respiratory failure (hARF) consequent to...

Superior Vena Cava Syndrome from Percutaneous Right Ventricular Assist Device Use in Right Ventricular Failure

Percutaneous right ventricular assist device (RVAD) support with right internal jugular (IJ) vein access has emerged as a viable solution for treating refractory RV failure. Recent reports have shown that RVAD support with this approach can be beneficial in a variety of clinical scenarios including post cardiotomy RV failure, cardiogenic shock, and severe acute hypoxemic respiratory failure with associated RV dysfunction, as well as decreased mortality compared to surgically implanted RVADs. However, the safety profile of such devices has not been characterized. A comprehensive retrospective review was completed for all patients receiving percutaneous RVAD support via a right internal jugular route with either 28 or 31F cannula at our institution between April 2017 and December 2018. Preoperative patient demographics, intraoperative, and postoperative outcomes, with specific focus on device related complications. Fourty patients (27 men, 67.5%) with mean age of 52 years ± 15.6 and refractory RV failure were managed with a percutaneous RVAD inserted through the right IJ. Of these 40 patients, 3 (7.5%) patients demonstrated device related superior vena cava (SVC) syndrome resulting from obstruction of the SVC with the RVAD cannula. One patient managed by head of bed elevation and early removal of the device (I believe). Two were treated by connecting a "venting" tubing to the side port on the introducer sheath and placing into the ECMO circuit to for decompression. Symptoms resolved in all 3 patients and no deaths resulted from SVC syndrome. SVC syndrome related to percutaneous RVAD placement is an important, but previously undescribed postoperative complication of RVAD use. Early identification allows safe management of this complication, which does not detract from the safety of percutaneous RVAD support.

High-flow nasal oxygen reduces endotracheal intubation: a randomized clinical trial.

Background:The benefits of high-flow nasal cannula (HFNC) as primary intervention in patients with acute hypoxemic respiratory failure (AHRF) are still a matter in debate. Our objective was to compare HFNC therapy versus conventional oxygen therapy (COT) in the prevention of endotracheal intubation in this group of patients.Methods:An open-label, controlled and single-centre clinical trial was conducted in patients with severe AHRF, defined by a PaO2/FIO2 ratio ⩽200, to compare HFNC with a control group (CG) treated by COT delivered through a face mask, with the need to perform intubation as the primary outcome. The secondary outcomes included tolerance of the HFNC device and to look for the predictive factors for intubation in these patients.Results:A total of 46 patients were included (22 in the COT group and 24 in the HFNC group) 48% of whom needed intubation: 63% in the COT group and 33% in the HFNC group, with significant differences both in intention to treat [χ2 = 4.2; p = 0.04, relative risk (RR) = 0.5; confidence interval (CI) 95%: 0.3–1.0] and also in treatment analysis (χ2 = 4.7; p = 0.03; RR = 0.5; IC 95%: 0.3–0.9) We obtained a number needed to treat (NNT) = 3 patients treated to avoid an intubation. Intubation occurred significantly later in the HFNC group. Estimated PaO2/FIO2, respiratory rate and dyspnea were significantly better in the HFNC group. Patients treated with HFNC who required intubation presented significant worsening after the first 8 h, as compared with non-intubated HFNC group patients. Mortality was 22% with no differences. The HFNC group patients were hospitalized for almost half of the time in the intensive care unit (ICU) and in the ward, with significantly less hospital length of stay. A total of 14 patients in the HFNC group (58%) complained of excessive heat and 17% of noise; 3 patients did not tolerate HFNC.Conclusion:Patients with severe acute hypoxemic respiratory failure who tolerate HFNC present a significantly lower need for endotracheal intubation compared with conventional oxygen therapy.Clinical Trial RegisterEUDRA CT number: 2012-001671-36 The reviews of this paper are available via the supplemental material section.

High-flow nasal oxygen therapy alone or with non-invasive ventilation in immunocompromised patients admitted to ICU for acute hypoxemic respiratory failure: the randomised multicentre controlled FLORALI-IM protocol

IntroductionNon-invasive ventilation (NIV) is recommended as first-line therapy in respiratory failure of critically ill immunocompromised patients as it can decrease intubation and mortality rates as compared with standard oxygen. However,...

Single Center Experience with a Percutaneous Right Ventricular Assist Device in the Management of Right Ventricular Failure

Purpose Right ventricular assist device (RVAD) support can be beneficial in a variety of clinical scenarios including post cardiotomy RV failure, cardiogenic shock, and severe acute hypoxemic respiratory failure with associated RV dysfunction. Reported mortality after RVAD insertion ranges from 37% to 46%. Percutaneous RVAD support via right internal jugular vein has emerged with the potential for enhanced weaning and ambulation strategies. However, the experience with such an approach remains limited. Methods A comprehensive retrospective review was completed for all patients receiving percutaneous RVAD support via a right internal jugular route at our institution between April 2017 and September 2018. Successful weaning from support, in-hospital mortality, and freedom from device related complications were assessed. Results Percutaneous RVAD support was instituted in 31 patients (22 men, 71%) with a median age of 58 years (19 to 77 years). Indications for implantation were divided into 3 groups. Group 1: Post cardiotomy support (n=18, 58%) including following LVAD insertion, pulmonary thromboendarterectomy, bilateral lung transplant, or cardiac transplantation, Group 2: Cardiogenic shock (n=7, 23%), and Group 3: Primary respiratory failure (n=6, 19 %). There were no failures to wean RVAD in Group 1, compared with 67% failure to wean in Group 2 and 33% in Group 3. Median duration of support in Group 1 was 16 (7-36) days, 5 (1-16) days in Group 2, and 13 (8-18) days in Group 3. All-cause mortality for the entire cohort was 29%. Mortality in Group 1 was 2/18 (11%), Group 2 was 4/7 (57%), and Group 3 was 3/6 (50%). Complications included postoperative bleeding requiring reoperation in 7 (23%) patients, device related superior vena cava obstruction in 3 patients (10%), and device migration in 2 (6%) patients. There were no device-related infections, DVT, valvular damage, or pulmonary emboli observed in this cohort. No patients required transition to implantable long-term RVAD. Conclusion Percutaneous RVAD support appears to be a versatile and effective tool for treating patients with severe RV failure, with best outcomes in the post cardiotomy group. The ability to ambulate these patients while on support and remove the device at the bedside without surgery may permit a more liberal use of this technology with improvements in outcomes in RV failure.

High-Flow Nasal Oxygen Reduces Endotracheal Intubation: A Randomised Clinical Trial

Background The benefits of High-flow nasal cannula (HFNC) as primary intervention in patients with acute hypoxemic respiratory failure (AHRF) are still unknown. Our objective was to compare the HFNC therapy vs the conventional oxygen therapy (CO) in the prevention of endotracheal intubation (EI) in this patients. Methods Controlled clinical trial in patients with severe AHRF, to compare the HFNC with a control group (CG) treated by CO delivered through a face mask, on the need to perform EI. Findings Forty-six patients were included, 48% of whom needed EI: 63% in the CG and 33% in the IG, with significant differences (x2Pearson=4·7; p=0·03; RR= 0·5; IC95%:0·3-0·9). We obtained a NNT=3 patients treated to avoid an EI. EI occurred significantly later in the IG. Estimated_PaO2/FiO2, respiratory rate, and dyspnea were significantly better in the IG. Patients treated with HFNC who required EI presented a significant worsening after the first 8 hours, as compared to non-intubated IG patients. Mortality was 22% with no differences. The IG patients were hospitalized for almost half of the time in the ICU and in the ward, with significantly less hospital length of stay. Fourteen patients in the IG (58%) complained of excessive heat and 17% of noise. Three patients did not tolerate the HFNC. Interpretation Patients with severe acute hypoxemic respiratory failure who tolerate HFNC present a significantly lower need for endotracheal intubation compared to conventional oxygen therapy. Trial Registration Number: EUDRA CT number: 2012-001671-36 Funding: This study received a funding from: Spanish Ministry of Health, Social Services, and Equality. (No Exp.: EC11-103). Declaration of Interest: All authors declare no conflicts of interest. Ethical Approval: The study was reviewed and approved by University Hospital La Princesa Institutional Review Board. All study participants or their legal guardian, provided informed consent prior to study.

Prone positioning in severe acute hypoxemic respiratory failure in the emergency ward

This paper reports the authors’ preliminary experience with three patients affected by severe acute hypoxemic respiratory failure due to bilateral pneumonia placed in a prone position in Emergency Medicine Ward during application of high flow oxygen nasal cannula.

The efficacy of initial ventilation strategy for adult immunocompromised patients with severe acute hypoxemic respiratory failure: study protocol for a multicentre randomized controlled trial (VENIM)

BackgroundAcute respiratory failure (ARF) is still one of the most severe complications in immunocompromised patients. Our previous systematic review showed noninvasive mechanical ventilation (NIV) reduced mortality, length of hospitalization and ICU stay in AIDS/hematological malignancy patients with relatively less severe ARF, compared to invasive mechanical ventilation (IMV). However, this systematic review was based on 13 observational studies and the quality of evidence was low to moderate. The efficacy of NIV in more severe ARF and in patients with other causes of immunodeficiency is still unclear. We aim to determine the efficacy of the initial ventilation strategy in managing ARF in immunocompromised patients stratified by different disease severity and causes of immunodeficiency, and explore predictors for failure of NIV.Methods and analysisThe VENIM is a multicentre randomized controlled trial (RCT) comparing the effects of NIV compared with IMV in adult immunocompromised patients with severe hypoxemic ARF. Patients who meet the indications for both forms of ventilatory support will be included. Primary outcome will be 30-day all-cause mortality. Secondary outcomes will include in-hospital mortality, length of stay in hospital, improvement of oxygenation, nosocomial infections, seven-day organ failure, adverse events of intervention, et al. Subgroups with different disease severity and causes of immunodeficiency will also be analyzed.DiscussionVENIM is the first randomized controlled trial aiming at assessing the efficacy of initial ventilation strategy in treating moderate and severe acute respiratory failure in immunocompromised patients. The result of this RCT may help doctors with their ventilation decisions.Trial registrationClinicalTrials.gov NCT02983851. Registered 2 September 2016.

A Technique of Awake Bronchoscopic Endotracheal Intubation for Respiratory Failure in Patients With Right Heart Failure and Pulmonary Hypertension.

Patients with pulmonary hypertension and right heart failure have a high risk of clinical deterioration and death during or soon after endotracheal intubation. The effects of sedation, hypoxia, hypoventilation, and changes in intrathoracic pressure can lead to severe hemodynamic instability. In search for safer approach to endotracheal intubation in this cohort of patients, we evaluate the safety and feasibility of an alternative intubation technique. Retrospective data analysis. Two medical ICUs in large university hospitals in the United States. We report a case series of nine nonconsecutive patients with compromised right heart function, pulmonary hypertension, and severe acute hypoxemic respiratory failure who underwent endotracheal intubation with a novel technique combining awake bronchoscopic intubation supported with nasally delivered noninvasive positive pressure ventilation or high-flow nasal cannula. All patients were intubated in the first attempt without major complications and eight patients (88%) were alive 24 hours after intubation. Systemic hypotension was the most frequent complication following the procedure. Awake bronchoscopic intubation supported with a noninvasive positive pressure delivery systems may be feasible alternative to standard direct laryngoscopy approach. Further studies are needed to better assess its safety and applicability.

Thromboembolic events in patients with severe pandemic influenza A/H1N1

BackgroundThe 2009 pandemic influenza A/H1N1 developed as a novel swine influenza which caused more diseases among younger age groups than in the elderly. Severe hypoxemic respiratory failure from A/H1N1 pneumonia resulted in an increased need for ICU beds. Several risk groups were identified that were at a higher risk for adverse outcomes. Pregnant women were a particularly vulnerable group of patients The CDC reported on the first ten patients with severe illness and acute hypoxemic respiratory failure associated with A/H1N1 infection, none of whom were pregnant, but they noticed that half of the patients had a pulmonary embolism. MethodsDuring a four-month period from September to December 2009, 252 patients were admitted to our hospital with confirmed pandemic influenza H1N1 by real-time reverse transcriptase-polymerase chain reaction test (rRT-PCR). We cared for twenty patients (7.9%) admitted to MICU with severe A/H1N1. Results on Thrombotic events were identified in five (25%) of our critically ill patients. ConclusionsWe recommend that patients with severe influenza A/H1N1 pneumonitis and respiratory failure be administered DVT prophylaxis in particular if there are additional risk factors for TVE. Further prospective studies on the relationship of influenza A/H1N1 and VTE are needed.

Noninvasive ventilation for acute respiratory failure.

This article reviews the use of noninvasive ventilation (NIV) in patients with acute respiratory failure (ARF), with a critical review of the most recent literature in this setting. The efficacy of NIV is variable depending on the cause of the episode of ARF. In community-acquired pneumonia, NIV is often associated with poor response, with better response in patients with preexisting cardiac or respiratory disease. In patients with pandemic influenza H1N1 and severe ARF, NIV has been associated with high failure rates but relatively favorable mortality. In acute respiratory distress syndrome, NIV should be used very cautiously and restricted to patients with mild-moderate acute respiratory distress syndrome without shock or metabolic acidosis due to the high failure rate observed in several reports. Despite limited evidence, NIV may improve the outcomes of patients with chest trauma and severe ARF. In postoperative ARF, both continuous positive airway pressure and NIV are effective to improve clinical outcomes, particularly in those with abdominal, cardiac, and thoracic surgery. Although patients with severe hypoxemic ARF are, in general, less likely to be intubated when NIV is used, the efficacy is different among these heterogeneous populations. Therefore, NIV is not routinely recommended in all patients with severe hypoxemic ARF.

NIV-Helmet in Severe Hypoxemic Acute Respiratory Failure.

Noninvasive ventilation (NIV) is a method to be applied in acute respiratory failure, given the possibility of avoiding tracheal intubation and conventional ventilation. A previous healthy 5-month-old boy developed low-grade intermittent fever, flu-like symptoms, and dry cough for 3 days. On admission, he showed severe respiratory distress with SpO2/FiO2 ratio of 94. Subsequent evaluation identified an RSV infection complicated with an increase of inflammatory parameters (reactive C protein 15 mg/dL). Within the first hour after NIV-helmet CPAP SpO2/FiO2 ratio increased to 157. This sustained improvement allowed the continuing of this strategy. After 102 h, he was disconnected from the helmet CPAP device. The NIV use in severe hypoxemic acute respiratory failure should be carefully monitored as the absence of clinical improvement has a predictive value in the need to resume to intubation and mechanical ventilation. We emphasize that SpO2/FiO2 ratio is a valuable monitoring instrument. Helmet interface use represents a more comfortable alternative for providing ventilatory support, particularly to small infants, which constitute a sensitive group within pediatric patients.

Unraveling the mysteries of Middle East respiratory syndrome coronavirus.

Unraveling the mysteries of Middle East respiratory syndrome coronavirus.

Helmet CPAP vs. oxygen therapy in severe hypoxemic respiratory failure due to pneumonia.

The efficacy of noninvasive continuous positive airway pressure (CPAP) to improve outcomes in severe hypoxemic acute respiratory failure (hARF) due to pneumonia has not been clearly established. The aim of this study was to compare CPAP vs. oxygen therapy to reduce the risk of meeting criteria for endotracheal intubation (ETI). In a multicenter randomized controlled trial conducted in four Italian centers patients with severe hARF due to pneumonia were randomized to receive helmet CPAP (CPAP group) or oxygen delivered with a Venturi mask (control group). The primary endpoint was the percentage of patients meeting criteria for ETI, including either one or more major criteria (respiratory arrest, respiratory pauses with unconsciousness, severe hemodynamic instability, intolerance) or at least two minor criteria (reduction of at least 30% of basal PaO2/FiO2 ratio, increase of 20% of PaCO2, worsening of alertness, respiratory distress, SpO2 less than 90%, exhaustion). Between February 2010 and 2013, 40 patients were randomized to CPAP and 41 to Venturi mask. The proportion of patients meeting ETI criteria in the CPAP group was significantly lower compared to those in the control group (6/40 = 15% vs. 26/41 = 63%, respectively, p < 0.001; relative risk 0.24, 95% CI 0.11-0.51; number needed to treat, 2) two patients were intubated in the CPAP group and one in the control group. The CPAP group showed a faster and greater improvement in oxygenation in comparison to controls (p < 0.001). In either study group, no relevant adverse events were detected. Helmet CPAP reduces the risk of meeting ETI criteria compared to oxygen therapy in patients with severe hARF due to pneumonia.

Clinical Course and Outcomes of Critically Ill Patients With Middle East Respiratory Syndrome Coronavirus Infection

Since September 2012, 170 confirmed infections with Middle East respiratory syndrome coronavirus (MERS-CoV) have been reported to the World Health Organization, including 72 deaths. Data on critically ill patients with MERS-CoV infection are limited. To describe the critical illness associated with MERS-CoV. Case series. 3 intensive care units (ICUs) at 2 tertiary care hospitals in Saudi Arabia. 12 patients with confirmed or probable MERS-CoV infection. Presenting symptoms, comorbid conditions, pulmonary and extrapulmonary manifestations, measures of severity of illness and organ failure, ICU course, and outcome are described, as are the results of surveillance of health care workers (HCWs) and patients with potential exposure. Between December 2012 and August 2013, 114 patients were tested for suspected MERS-CoV; of these, 11 ICU patients (10%) met the definition of confirmed or probable cases. Three of these patients were part of a health care-associated cluster that also included 3 HCWs. One HCW became critically ill and was the 12th patient in this case series. Median Acute Physiology and Chronic Health Evaluation II score was 28 (range, 16 to 36). All 12 patients had underlying comorbid conditions and presented with acute severe hypoxemic respiratory failure. Most patients (92%) had extrapulmonary manifestations, including shock, acute kidney injury, and thrombocytopenia. Five (42%) were alive at day 90. Of the 520 exposed HCWs, only 4 (1%) were positive. The sample size was small. MERS-CoV causes severe acute hypoxemic respiratory failure and considerable extrapulmonary organ dysfunction and is associated with high mortality. Community-acquired and health care-associated MERS-CoV infection occurs in patients with chronic comorbid conditions. The health care-associated cluster suggests that human-to-human transmission does occur with unprotected exposure. None.

The art and science of non-invasive ventilation

Non-invasive ventilation (NIV) is one of the most relevant recent advances in the management of patients with severe acute respiratory failure (ARF). NIV is considered a standard of care for the management of hypercapnic ARF in patients with acute exacerbation of chronic obstructive pul- monary disease. With an appropriate selection of patients, NIV can reduce the need for invasive me- chanical ventilation, mortality and length of stay. Patients with severe hypoxemic ARF have in gen- eral a lower likelihood to need tracheal intubation when NIV as a support for ARF is added to the standard medical treatment. However, the effects of NIV on mortality are less evident, and the het- erogeneity of the different published studies sug- gests that the efficacy may be different among dif- ferent populations. The optimal time for intubation after NIV failure remains a challenging issue due to increasing evidences on the relationship be- tween delayed intubation and excess mortality in these populations. In intubated patients with pre- existing lung disease, the use of NIV in order to advance extubation during difficult and prolonged weaning can result in reduced periods of endotra- cheal intubation, complication rates and improved survival. Moreover, NIV immediately after extuba- tion is effective in avoiding respiratory failure after extubation and improving survival in patients at risk for this complication, particularly those with chronic respiratory disorders, cardiac co-morbidi- ty, and hypercapnic respiratory failure. KEY WORDS:

Mechanical insufflation-exsufflation in prevention of post-extubation acute respiratory failure: most welcome but must be used cautiously in critically ill patients

In a study published in the previous issue of Critical Care, Goncalves and colleagues [1] observed a 33% reduction in re-intubation rate in the study group, due to eff ective management of bronchial secretions. Current evidence favors early implementation of noninvasive mechanical ventilation (NIV) in the post-extubation period to reduce re-intubation, especially in patients with hypercapnic respiratory failure [2-4]. However, some important practical issues need to be considered before the use of mechanical insuffl ationexsufl ation (MI-E) in the post-extubation period can be generalized, especially in patients needing NIV: (a) MI-E application requires that the NIV mask be disconnected, resulting in positive pressure loss, alveolar collapse, and desaturation. (b) MI-E devices do not have entrained oxygen. Hence, any rapid desaturation episode will require immediate reconnection to NIV. (c) Assessment of the eff ective management of bronchial secretions can prove diffi cult because of the lack of an objective or specifi c scoring system. (d) In some situations requiring several MI-E sessions, frequent disconnection from NIV can lead to prolonged use of post-extubation NIV. (e) MI-E may be diffi cult to perform or may lead to poor compliance in cases of unplanned extubation, moderate to severe hypoxemic acute respiratory failure (ARF) after extubation, agitation/anxiety, and tachypnea. (f ) Th e eff ectiveness of MI-E should be studied beyond 48 hours, as late-onset extubation failures and post-extubation NIV failures are due mostly to ineff ective secretion clearance [5]. In conclusion, we believe that this original study could have an impact on the management and prevention of post-extubation ARF in a select group of patients. However, owing to the above-mentioned reasons, the use of MI-E cannot be generalized to all patient populations.

Rescue treatment for noninvasive ventilation failure due to interface intolerance with remifentanil analgosedation: a pilot study

To assess the feasibility of remifentanil-based sedation in hypoxemic acute respiratory failure (HARF) patients refusing to continue noninvasive ventilation (NPPV) for intolerance to two different interfaces-helmet and total face mask. Prospective uncontrolled clinical investigation in a 14-bed ICU of an university hospital in Italy. Thirty-six patients with persistent severe HARF who complained of discomfort and asked for interruption of NPPV session. Patients started sedation with remifentanil (0.025 μg kg(-1) min(-1)) and the infusion rate was increased by 0.01 μg kg(-1) min(-1) every minute to a maximum of 0.12 μg kg(-1) min(-1) to obtain patient comfort. Twenty-two out of 36 patients (61%) with median (IQR) SAPS II score of 32 (30, 38) continued the NPPV treatment after the introduction of remifentanil infusion. In this success group, median (IQR) respiratory rate decreased from 34 (31, 37) to 24 (20, 26) min(-1) (p < 0.0001) and PaO(2)/FiO(2) ratio increased from 156 (144, 176) to 270 (210, 300) mmHg (p < 0.0001) after 1 h of NPPV with remifentanil-analgosedation either with helmet or total face mask. Fourteen patients failed to continue the noninvasive treatment and were intubated after a mean of 2.5 ± 2.3 h; they showed a respiratory rate decrease from 35 (30, 38) to 27 (25, 35) min(-1) (p = 0.02) and an inability to increase the PaO(2)/FiO(2) ratio above 180 mmHg. The ICU mortality in the failure group patients was 50 versus 14% in the NPPV success group (p < 0.05). The mean remifentanil dose administered was 0.07 ± 0.03 μg kg(-1) min(-1). This clinical study suggests that a remifentanil-based sedation protocol can decrease the rate of failure in patients with intolerance to NPPV.

Non-invasive positive pressure ventilation in patients with acute hypoxemic respiratory failure: a prospective cohort study

To investigate the clinical effect of non-invasive positive pressure ventilation (NPPV) on acute hypoxemic respiratory failure (AHRF), and to look for predictors of failure of NPPV in patients with AHRF. In the cohort study, the clinical data of patients with AHRF in respiratory intensive care unit (RICU) of Beijing Chaoyang Hospital from January 2004 to December 2007 were collected prospectively. Patients were divided into successful group and failure group according to outcome of NPPV. Basic clinical information, NPPV mode and duration, vital signs, arterial blood gas analysis, and oxygenation index (PaO(2)/FiO(2)) before and 2 hours, 24 hours after NPPV were analyzed and compared between two groups. (1)The NPPV successful rate in 59 cases was 62.7% (37/59). (2)Compared with failure group, mean age, the ratio of patients in whom respiratory failure were induced by pulmonary infection were lower in successful group (both P<0.01). There was no difference in PaO(2)/FiO(2)between two groups before NPPV, but PaO(2)/FiO(2) in successful group was markedly higher than those of failure group after 2 hours and 24 hours of NPPV (P<0.05 and P<0.01), while heart rate (HR), respiratory rate (RR) were significantly lower (all P<0.01). (3)Logistic regression analysis identified age > or = 60 years [odds ratio (OR) 8.30, 95% confidence interval (CI) 2.49-27.60, P=0.002], pulmonary infection as underlying disease of respiratory failure (OR 6.19, 95%CI 1.90-20.20, P=0.027), PaO(2)/FiO(2)<150 mm Hg (1 mm Hg=0.133 kPa) after 2 hours of NPPV (OR 3.65, 95%CI 1.20-11.04, P=0.044), HR>100 times/min after 24 hours of NPPV (OR 7.45, 95%CI 2.15-25.58, P=0.010), and RR>30 times/min after 24 hours of NPPV (OR 7.26, 95%CI 1.88-24.49, P=0.018) as risk factors independently associated with failure of NPPV. NPPV can be the first line treatment for severe AHRF patients without absolute contraindication, while patients of older age with pulmonary infection, the risk of failure of NPPV is higher. Lack of improvement in cardiorespiratory and oxygenation condition after a short period of NPPV is the predictor of NPPV failure.

Short-term effects of prone position in chronic obstructive pulmonary disease patients with severe acute hypoxemic and hypercapnic respiratory failure

To assess the short-term effects of prone positioning (PP) in chronic obstructive pulmonary disease (COPD) patients with severe hypoxemic and hypercapnic respiratory failure requiring invasive mechanical ventilation. Prospective observational study in the general intensive care unit of a university-affiliated hospital. 11 consecutive COPD patients with persistent hypoxemia (PaO2/FIO2 < or = 200 mmHg with FIO2 > or = 0.6) and hypercapnia requiring invasive mechanical ventilation. Patients with adult respiratory distress syndrome or left ventricular failure were excluded. Mean age was 73+/-11 years, mean weight 86+/-31 kg, mean SAPS II 53+/-10, and ICU mortality 36%. Patients were turned every 6 h. A response to PP (20% or greater PaO2/FIO2 increase) was noted in 9 (83%) patients. Blood gases were measured in the PP and supine (SP) positions 3 h after each turn, for 36 h, yielding six measurement sets (SP1, PP1, SP2, PP2, SP3, and PP3). PaO2/FIO2 was significantly better in PP: 190+/-26 vs. 113+/-9 mmHg for PP1/SP1, 175+/-22 vs. 135+/-16 mmHg for PP2/SP2, and 199+/-24 vs. 151+/-13 mmHg for PP3/SP3. After PP1 PaO2/FIO2 remained significantly improved, and the PaO2/FIO2 improvement from SP1 to SP2 was linearly related to PaO2/FIO2 during PP1 (r=0.8). The tracheal aspirate volume improved significantly from SP1 to PP1. PaCO2 was not significantly affected by position. PP was effective in treating severe hypoxemia in COPD patients. The first turn in PP was associated with increased tracheal aspirate.