Faculty of 1000 evaluation for Epidemiology, patterns of care, and mortality for patients with acute respiratory distress syndrome in intensive care units in 50 countries.

Introduction: In Obesity-Hypoventilation-Syndrome (OHS), pulmonary hypertension (PH) is considered a common feature. Aims: To determine frequency and severity of PH in OHS patients treated with non-invasive pressure ventilation (NPPV). Methods: Prospective cross-sectional study of consecutive patients admitted for follow-up of NPPV (initiated ≥3 months before). OHS was defined by BMI≥30kg/m 2 , capillary carbondioxid tension (PaCO 2 )≥45mmHg prior NPPV initiation without other causes for hypoventilation. Right-heart catheterization (RHC) was performed at rest without oxygen supplementation, daytime sleepiness measured by Epworth Sleepiness Scale (ESS). Results: 177 patients considered to have OHS were screened. Among 64 patients who met the diagnosis criteria for OHS, 21 patients (10f, 11m; median age 62.2 [53.9;71.7] years, BMI 45 [40;53] kg/m 2 , PaCO 2 39.6 [37.8;45.5] mmHg) gave consent for RHC. Only 4 (19%) patients had normal mean pulmonary artery pressure (mPAP 2 /cm 5 ; 8 patients (38.1%) presented with “Borderline”-PH (mPAP 20-24mmHg), mPAP 22 [22.5;23] mmHg and PVRI 392 [287;485] and 9 patients (42.9%) had a manifest PH (mPAP≥25mmHg), mPAP 33 [29;34] mmHg and PVRI 440 [384;728]. In 3 patients with PH, pulmonary capillary wedge pressure was >15mmHg; 2 of them presented with transpulmonary pressure gradient >12mmHg. In patients with PH, ESS (7 [6;11]) was significantly higher than in those without PH (3 [0.5;5.5], p=0.03) or Borderline-PH (3.5 [2.5;6.5], p=0.03). Conclusion: Mild to moderate PH is quite frequent in OHS, even after initiation of NPPV. Its impact on survival and quality of life has to be studied in future trials.

Pulmonary hypertension in obesity-hypoventilation-syndrome

BACKGROUND
Global epidemiological data regarding outcomes for patients in intensive care units (ICUs) are scarce, but are important in understanding the worldwide burden of critical illness. We, therefore, did an international audit of ICU patients worldwide and assessed variations between hospitals and countries in terms of ICU mortality.


METHODS
730 participating centres in 84 countries prospectively collected data on all adult (>16 years) patients admitted to their ICU between May 8 and May 18, 2012, except those admitted for fewer than 24 h for routine postoperative monitoring. Participation was voluntary. Data were collected daily for a maximum of 28 days in the ICU and patients were followed up for outcome data until death or hospital discharge. In-hospital death was analysed using multilevel logistic regression with three levels: patient, hospital, and country.


FINDINGS
10,069 patients were included from ICUs in Europe (5445 patients; 54·1%), Asia (1928; 19·2%), the Americas (1723; 17·1%), Oceania (439; 4·4%), the Middle East (393; 3·9%), and Africa (141; 1·4%). Overall, 2973 patients (29·5%) had sepsis on admission or during the ICU stay. ICU mortality rates were 16·2% (95% CI 15·5-16·9) across the whole population and 25·8% (24·2-27·4) in patients with sepsis. Hospital mortality rates were 22·4% (21·6-23·2) in the whole population and 35·3% (33·5-37·1) in patients with sepsis. Using a multilevel analysis, the unconditional model suggested significant between-country variations (var=0·19, p=0·002) and between-hospital variations (var=0·43, p<0·0001) in the individual risk of in-hospital death. There was a stepwise increase in the adjusted risk of in-hospital death according to decrease in global national income.


INTERPRETATION
This large database highlights that sepsis remains a major health problem worldwide, associated with high mortality rates in all countries. Our findings also show a significant association between the risk of death and the global national income and suggest that ICU organisation has an important effect on risk of death.


FUNDING
None.

Assessment of the worldwide burden of critical illness- the Intensive Care Over Nations (ICON) audit - APENDIX

Diaphragm dysfunction and weaning-induced pulmonary oedema are commonly involved during weaning failure, but their physiological interactions have been poorly reported. Our hypothesis was that diaphragm dysfunction is not particularly associated with weaning-induced pulmonary oedema. It was a single-centre and physiological study conducted in patients who had failed a first spontaneous breathing trial and who underwent a second trial. The diaphragm function was evaluated by measuring the tracheal pressure generated in response to a bilateral magnetic phrenic nerves stimulations. Weaning-induced pulmonary oedema was diagnosed in case of failure of the spontaneous breathing trial if patients exhibited signs of plasma concentration or echocardiographic diagnosis of pulmonary artery occlusion pressure elevation. Fifty-three patients were included and 31/53 (58%) failed the spontaneous breathing trial, including 24/31 (77%) patients with weaning-induced pulmonary oedema. Diaphragm dysfunction was present in 33/53 (62%) patients. Diaphragm dysfunction or weaning-induced pulmonary oedema were present in 26/31 (84%) of the patients who failed the spontaneous breathing trial. Weaning-induced pulmonary oedema occurred in 20/33 (61%) patients with a diaphragm dysfunction and in 4/20 (20%) patients without (p = 0.005). Weaning-induced pulmonary oedema was three times more frequent in case of diaphragm dysfunction. Even in case of diaphragm dysfunction, physicians might be encouraged to investigate the presence of weaning-induced pulmonary oedema during weaning failure.

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Diaphragm dysfunction, lung aeration loss and weaning-induced pulmonary oedema in difficult-to-wean patients.

The predictive value of airway occlusion pressure at 100 msec (P0.1) on successful weaning from mechanical ventilation: A systematic review and meta-analysis.

During spontaneous breathing trial, low-pressure support is thought to compensate for endotracheal tube resistance, but it actually should provide overassistance. Automatic tube compensation is an option available in the ventilator to compensate for flow-resistance of endotracheal tube. Its effects on patient effort have been poorly investigated. We aimed to compare the effects of low-pressure support and automatic tube compensation during spontaneous breathing trial on breathing power and lung ventilation distribution. We performed a randomized crossover study in 20 patients ready to wean. Each patient received both methods for 30 min separated by baseline ventilation: pressure support 0 cmH2O and automatic tube compensation 100% in one period and pressure support 7 cmH2O without automatic tube compensation in the other period, a 4 cmH2O positive end-expiratory pressure being applied in each. Same ventilator brand (Evita XL, Draeger, Germany) was used. Breathing power was assessed from Campbell diagram with esophageal pressure, airway pressure, flow and volume recorded by a data logger. Lung ventilation distribution was assessed by using electrical impedance tomography (Pulmovista, Draeger, Germany). During the last 2 min of low-pressure support and automatic compensation period breathing power and lung ventilation distribution were measured on each breath. Breathing power generated by the patient’s respiratory muscles was 7.2 (4.4–9.6) and 9.7 (5.7–21.9) J/min in low-pressure support and automatic tube compensation periods, respectively (P = 0.011). Lung ventilation distribution was not different between the two methods. We found that ATC was associated with higher breathing power than low PS during SBT without altering the distribution of lung ventilation.

/pdf/low-pressure-support-vs-automatic-tube-compensation-during-47twfzdmou.pdf

Low-pressure support vs automatic tube compensation during spontaneous breathing trial for weaning

BACKGROUND: Obesity-hypoventilation syndrome (OHS) is defined as the combination of obesity (body mass index ≥ 30 kg/m2) and daytime arterial hypercapnia (PaCO2 > 45 mm Hg) in the absence of other causes of hypoventilation, and can lead to acute hypercapnic respiratory failure in the ICU. Our objective was to describe the ventilatory management and outcomes of subjects with OHS who were admitted to the ICU for acute hypercapnic respiratory failure. METHODS: We retrospectively built a cohort of subjects with OHS who were admitted for acute hypercapnic respiratory failure in 4 ICUs of the university teaching hospital in Lyon, France, between 2013 and 2017. The main end point was the rate of success of noninvasive ventilation (NIV). Secondary end points were survival from OHS diagnosis to the last follow-up and risk factors for ICU admission and long-term survival. RESULTS: One hundred fifteen subjects with OHS were included. Thirty-seven subjects (32.1%) were admitted to the ICU for acute hypercapnic respiratory failure. Congestive heart failure was the leading cause of acute hypercapnic respiratory failure (54%). At ICU admission, pH before NIV use was median (range) 7.26 (7.22–7.31) and PaCO2 was 70 (61–76) mm Hg. NIV was used as first-line ventilatory support in 36 subjects (97.2%) and was successful in 33 subjects (91.7%). ICU mortality was low (2.7%). The subjects admitted to the ICU were significantly older and had a lower FEV1 and vital capacity at the time of an OHS diagnosis. The difference in the restricted mean survival time was 663 d in favor of subjects not admitted to the ICU. Multivariate analysis showed that lower vital capacity at an OHS diagnosis was significantly associated with a higher risk of ICU admission. No factor was independently associated with long-term overall mortality in multivariate analysis. CONCLUSIONS: Acute hypercapnic respiratory failure in subjects with OHS was generally responsive to NIV and was frequently associated with congestive heart failure.

http://rc.rcjournal.com/content/respcare/64/12/1545.full.pdf

Acute Respiratory Failure in Obesity-Hypoventilation Syndrome Managed in the ICU.

Hemodynamic instability is a frequent complication of continuous renal replacement therapy (CRRT). Postural tests (i.e., passive leg raising in the supine position or Trendelenburg maneuver in the prone position) combined with measurement of cardiac output are highly reliable to identify preload-dependence and may provide new insights into the mechanisms involved in hemodynamic instability related to CRRT (HIRRT). We aimed to assess the prevalence and risk factors of HIRRT associated with preload-dependence in ICU patients. We conducted a single-center prospective observational cohort study in ICU patients with acute kidney injury KDIGO 3, started on CRRT in the last 24 h, and monitored with a PiCCO® device. The primary endpoint was the rate of HIRRT episodes associated with preload-dependence during the first 7 days after inclusion. HIRRT was defined as the occurrence of a mean arterial pressure below 65 mmHg requiring therapeutic intervention. Preload-dependence was assessed by postural tests every 4 h, and during each HIRRT episode. Data are expressed in median [1st quartile–3rd quartile], unless stated otherwise. 42 patients (62% male, age 69 [59–77] year, SAPS-2 65 [49–76]) were included 6 [1–16] h after CRRT initiation and studied continuously for 121 [60–147] h. A median of 5 [3–8] HIRRT episodes occurred per patient, for a pooled total of 243 episodes. 131 episodes (54% [CI95% 48–60%]) were associated with preload-dependence, 108 (44%, [CI95% 38–51%]) without preload-dependence, and 4 were unclassified. Multivariate analysis (using variables collected prior to HIRRT) identified the following variables as risk factors for the occurrence of HIRRT associated with preload-dependence: preload-dependence before HIRRT [odds ratio (OR) = 3.82, p   8 h (OR = 0.56, p < 0.05), lactate (OR = 1.21 per 1-mmol L−1 increase, p < 0.05), cardiac index (OR = 0.47 per 1-L min−1 m−2 increase, p < 0.001) and SOFA at ICU admission (OR = 0.91 per 1-point increase, p < 0.001). None of the CRRT settings was identified as risk factor for HIRRT. In this single-center study, HIRRT associated with preload-dependence was slightly more frequent than HIRRT without preload-dependence in ICU patients undergoing CRRT. Testing for preload-dependence could help avoiding unnecessary decrease of fluid removal in preload-independent HIRRT during CRRT.

/pdf/prevalence-and-risk-factors-of-hemodynamic-instability-1wd9kq4yss.pdf

Prevalence and risk factors of hemodynamic instability associated with preload-dependence during continuous renal replacement therapy in a prospective observational cohort of critically ill patients.

The Lung Safe study (Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE) was an observational international study performed in 459 intensive care units (ICUs) worldwide during the winter 2014 in patients with hypoxemic acute respiratory failure (1)

/pdf/acute-respiratory-distress-syndrome-a-worldwide-economic-24adsr7xgb.pdf

Nader Chebib

Papers

Low-pressure support vs automatic tube compensation during spontaneous breathing trial for weaning

Acute Respiratory Failure in Obesity-Hypoventilation Syndrome Managed in the ICU.

Prevalence and risk factors of hemodynamic instability associated with preload-dependence during continuous renal replacement therapy in a prospective observational cohort of critically ill patients.

Acute respiratory distress syndrome—a worldwide economic perspective