Association between pediatric intensive care mortality and mechanical ventilation settings during extracorporeal membrane oxygenation for pediatric acute respiratory distress syndrome.

The main objective of this study was to describe the current mechanical ventilation (MV) settings during extracorporeal membrane oxygenation (ECMO) for pediatric acute respiratory distress syndrome (P-ARDS) in six European centers. This is a retrospective observational cohort study performed in six European centers from January 2009 to December 2019. Children > 1 month to 18 years supported with ECMO for refractory P-ARDS were included. Collected data were as follows: patients' pre-ECMO medical condition, pre-ECMO adjunctive therapies for P-ARDS, pre-ECMO and during ECMO MV settings on day (D) 1, D3, D7, and D14 of ECMO, use of adjunctive therapies during ECMO, duration of ECMO, pediatric intensive care unit length of stay, and survival. A total of 255 patients with P-ARDS were included. The multivariate analysis showed that PEEP on D1 (OR = 1.13, 95% CI [1.03-1.24], p = 0.01); D3 (OR = 1.17, 95% CI [1.06-1.29], p = 0.001); and D14 (OR = 1.21, 95% CI [1.05-1.43], p = 0.02) and DP on D7 were significantly associated with higher odds of mortality (OR = 0.82, 95% CI [0.71-0.92], p = 0.001). Moreover, DP on D1 above 15 cmH2O (OR 2.23, 95% CI (1.09-4.71), p = 0.03) and native lung FiO2 above 60% on D14 (OR 10.36, 95% CI (1.51-116.15), p = 0.03) were significantly associated with higher odds of mortality.   Conclusion: MV settings during ECMO for P-ARDS varied among centers; however, use of high PEEP levels during ECMO was associated with higher odds of mortality as well as a DP above 15 cmH2O and a native lung FiO2 above 60% on D14 of ECMO. What is Known: • Invasive ventilation settings are well defined for pediatric acute respiratory distress syndrome; however, once the children required an extracorporeal respiratory support, there is no recommendation how to set the mechanical ventilator. • Impact of invasive ventilator during extracorporeal respiratory support ad only been during the first days of this support but the effects of these settings later in the assistance are not described. What is New: • It seems to be essential to early decrease FiO2 on native lung once the ECMO flow allows an efficient oxygenation. • Tight control to limit the driving pressure at 15 cmH20 during ECMO run seems to be associated with better survival rate.

Do clinical parameters predict first planned extubation outcome in the pediatric intensive care unit?

CONTEXT: There is absence of evidence-based guidelines to determine extubation readiness in the pediatric intensive care unit (PICU). OBJECTIVE: Evaluate our practice of determining extubation readiness based on physician judgment of preextubation ventilator settings, blood gas analysis, and other factors potentially affecting extubation outcome. DESIGN: Prospective cohort study from August 2010 to April 2012. SETTING: Academic, multidisciplinary PICU. PATIENTS: A total of 319 PICU patients undergoing first planned extubation attempt. INTERVENTIONS: None. MEASUREMENTS: Determine the extubation success rate and evaluate factors potentially affecting extubation outcome. The PICU length of stay (LOS) and cost were also recorded. Subgroup analysis was performed based on days of mechanical ventilation (MV). RESULTS: A total of 319 consecutive patients underwent first planned extubation attempt with a 91% success rate. Factors associated with extubation failure were the length of MV (P < .0001, odds ratio [OR] 2.20); age (P = .02, OR 0.54); preextubation steroids (P = .04, OR 2.40); and postextubation stridor (P < .01, OR 3.40). Ventilator settings and blood gas results had no association with extubation outcome with 1 exception, ventilator rates ≤ 8 were associated with extubation failure in patients with ≤1 day of MV. Extubation failure was associated with prolonged PICU LOS and excess cost, with failures staying 14 days longer (P < .0001) and costing 3.2 time more (P < .0001) than successes. CONCLUSIONS: Physician judgment to determine extubation readiness led to a first planned extubation success rate of 91%. Age and the length of MV were primary risk factors for failed extubation. In patients with ≤1 day of MV, our findings suggest that confidence in extubation readiness following weaning to low ventilator rates may not be justified. Furthermore, reliance on preextubation ventilator settings and blood gas results to determine extubation readiness may lead to unnecessary prolongation of MV, thereby increasing the PICU LOS and excess cost. These findings are hypothesis generating and require further study for confirmation.

Ventilatory settings in the initial 72 h and their association with outcome in out-of-hospital cardiac arrest patients: a preplanned secondary analysis of the targeted hypothermia versus targeted normothermia after out-of-hospital cardiac arrest (TTM2) trial.

PURPOSE: The optimal ventilatory settings in patients after cardiac arrest and their association with outcome remain unclear. The aim of this study was to describe the ventilatory settings applied in the first 72 h of mechanical ventilation in patients after out-of-hospital cardiac arrest and their association with 6-month outcomes. METHODS: Preplanned sub-analysis of the Target Temperature Management-2 trial. Clinical outcomes were mortality and functional status (assessed by the Modified Rankin Scale) 6 months after randomization. RESULTS: A total of 1848 patients were included (mean age 64 [Standard Deviation, SD = 14] years). At 6 months, 950 (51%) patients were alive and 898 (49%) were dead. Median tidal volume (VT) was 7 (Interquartile range, IQR = 6.2-8.5) mL per Predicted Body Weight (PBW), positive end expiratory pressure (PEEP) was 7 (IQR = 5-9) cmH20, plateau pressure was 20 cmH20 (IQR = 17-23), driving pressure was 12 cmH20 (IQR = 10-15), mechanical power 16.2 J/min (IQR = 12.1-21.8), ventilatory ratio was 1.27 (IQR = 1.04-1.6), and respiratory rate was 17 breaths/minute (IQR = 14-20). Median partial pressure of oxygen was 87 mmHg (IQR = 75-105), and partial pressure of carbon dioxide was 40.5 mmHg (IQR = 36-45.7). Respiratory rate, driving pressure, and mechanical power were independently associated with 6-month mortality (omnibus p-values for their non-linear trajectories: p < 0.0001, p = 0.026, and p = 0.029, respectively). Respiratory rate and driving pressure were also independently associated with poor neurological outcome (odds ratio, OR = 1.035, 95% confidence interval, CI = 1.003-1.068, p = 0.030, and OR = 1.005, 95% CI = 1.001-1.036, p = 0.048). A composite formula calculated as [(4*driving pressure) + respiratory rate] was independently associated with mortality and poor neurological outcome. CONCLUSIONS: Protective ventilation strategies are commonly applied in patients after cardiac arrest. Ventilator settings in the first 72 h after hospital admission, in particular driving pressure and respiratory rate, may influence 6-month outcomes.

Evaluation of Short-term Outcomes of Tracheostomy Procedures in a NICU Population With High Ventilator Settings.

OBJECTIVE: To investigate whether tracheostomy placement in infants requiring high ventilator pressure is safe and effective. STUDY DESIGN: Case series with chart review. SETTING: Tertiary children's hospital. METHODS: Fifty ventilator-dependent neonatal intensive care unit patients who underwent tracheotomy from 2009 to 2018 were included. Patients requiring high ventilator pressures were compared to those requiring low ventilator pressures. Demographics, comorbidities, and surgical and clinical data were recorded. RESULTS: Thirty-two percent (n = 16) had low ventilator settings at the time of tracheostomy tube placement, and 68% (n = 34) had high ventilator settings. The median peak inspiratory pressure of the high ventilator group was 29.5 cm H2O, positive end-expiratory pressure (PEEP) was 8 cm H2O, mean airway pressure was 13 cm H2O, pressure support (PS) was 14 cm H2O, PS above PEEP was 6 cm H2O, and inspiratory time was 0.65 seconds. The high ventilator cohort had a higher median age at the time of surgery compared to the low ventilator group (P = .02). Female patients were more likely to have high ventilator settings (P = .02). There were no intraoperative complications or deaths within the first 7 days of tracheostomy tube placement. Pneumonia incidence and rate of mortality during admission did not vary by ventilator settings (P = .92 and P = .94, respectively). CONCLUSION: Few differences in tracheostomy tube placement outcomes were observed for patients with high ventilator settings compared to low ventilator settings. These data demonstrate that patients requiring high ventilator pressures can benefit from tracheostomy tube placement with no additional short-term risks.

Long-Term Noninvasive Ventilation in the Geneva Lake Area: Indications, Prevalence, and Modalities.

BACKGROUND: Noninvasive ventilation (NIV) is standard of care for chronic hypercapnic respiratory failure, but indications, devices, and ventilatory modes are in constant evolution. RESEARCH QUESTION: To describe changes in prevalence and indications for NIV over a 15-year period; to provide a comprehensive report of characteristics of the population treated (age, comorbidities, and anthropometric data), mode of implementation and follow-up, devices, modes and settings used, physiological data, compliance, and data from ventilator software. STUDY DESIGN AND METHODS: Cross-sectional observational study designed to include all subjects under NIV followed by all structures involved in NIV in the Cantons of Geneva and Vaud (1,288,378 inhabitants). RESULTS: A total of 489 patients under NIV were included. Prevalence increased 2.5-fold since 2000 reaching 38 per 100,000 inhabitants. Median age was 71 years, with 31% being > 75 years of age. Patients had been under NIV for a median of 39 months and had an average of 3 ± 1.8 comorbidities; 55% were obese. COPD (including overlap syndrome) was the most important patient group, followed by obesity hypoventilation syndrome (OHS) (26%). Daytime Paco2 was most often normalized. Adherence to treatment was satisfactory, with 8% only using their device < 3.5 h/d. Bilevel positive pressure ventilators in spontaneous/timed mode was the default mode (86%), with a low use of autotitrating modes. NIV was initiated electively in 50% of the population, in a hospital setting in 82%, and as outpatients in 15%. INTERPRETATION: Use of NIV is increasing rapidly in this area, and the population treated is aging, comorbid, and frequently obese. COPD is presently the leading indication followed by OHS. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT04054570; URL: www.clinicaltrials.gov.

Long-Term Non-invasive Ventilation: Do Patients Aged Over 75 Years Differ From Younger Adults?

Background: Noninvasive ventilation (NIV) is accepted as standard of care for chronic hypercapnic respiratory failure (CHRF) and is being increasingly implemented in older subjects. However, little is known regarding the use of NIV on a long-term basis in the very old. The outcomes of this study were: 1/to report the proportion of patients ≥ 75 years old (elderly) among a large group of long-term NIV users and its trend since 2000; 2/to compare this population to a younger population (<75 years old) under long-term NIV in terms of diagnoses, comorbidities, anthropometric data, technical aspects, adherence to and efficiency of NIV. Methods: In a cross-sectional analysis of a multicenter cohort study on patients with CHRF under NIV, diagnoses, comorbidities, technical aspects, adherence to and efficiency of NIV were compared between patients ≥ 75 and <75 years old (chi-square or Welch Student tests). Results: Of a total of 489 patients under NIV, 151 patients (31%) were ≥ 75 years of age. Comorbidities such as systemic hypertension (86 vs. 60%, p < 0.001), chronic heart failure (30 vs. 18%, p = 0.005), and pulmonary hypertension (25 vs. 14%, p = 0.005) were more frequent in older subjects. In the older group, there was a trend for a higher prevalence of chronic obstructive pulmonary disease (COPD) (46 vs. 36%, p = 0.151) and a lower prevalence of neuromuscular diseases (NMD) (19 vs. 11%, p = 0.151), although not significant. Adherence to and efficacy of NIV were similar in both groups (daily use of ventilator: 437 vs. 419 min, p = 0.76; PaCO2: 5.8 vs. 5.9 kPa, p = 0.968). Unintentional leaks were slightly higher in the older group (1.8 vs. 0.6 L/min, p = 0.018). Conclusions: In this cross-sectional study, one third of the population under NIV was ≥ 75 years old. Markers of efficacy of NIV, and adherence to treatment were similar when compared to younger subjects, confirming the feasibility of long-term NIV in the very old. Health-related quality of life was not assessed in this study and further research is needed to address this issue.

Driving Pressure: Defining the Range.

BACKGROUND: Recent literature suggests that optimization of tidal driving pressure (ΔP) would be a better variable to target for lung protection at the bedside than tidal volume (VT) or plateau pressure (Pplat), the traditional indicators of ventilator-induced lung injury. However, the usual range or variability of ΔP over time for any subject category have not been defined. This study sought to document the ΔP ranges observed in current practice among mechanically ventilated subjects receiving routine care for diverse acute conditions in a community hospital environment. METHODS: This was a retrospective, observational study in a university-affiliated and house staff-aided institution with respiratory care protocols based on extant lung-protective guidelines for VT. Demographic characteristics and measured parameters related to mechanical ventilation and hemodynamics were extracted from electronic records of intubated subjects for each 8-h period of the first 24 h in the ICU. Pplat values reported by the ventilator were validated by the respiratory therapist before those data were entered into the electronic medical record. RESULTS: The mean ΔP was significantly higher at Time 1 (mean 16.1, range 7.0-31.0 cm H2O) compared to both Time 2 (mean 14.5, range 7.0-35.0 cm H2O) (P < .001) and Time 3 (mean 14.8, range 8.0-32 cm H2O) (P < .001). At all time points, the median ΔP was higher for completely passive breathing compared to triggered breathing. The widest difference between presumed entirely passive and presumed intermittently or consistently triggered breaths occurred at Time 1 (mean ΔP = 17.2 vs 14.9 cm H2O, respectively) (P = .01). CONCLUSIONS: Suggested safety thresholds for ΔP are often violated by a strategy that focuses on only VT and Pplat. Our data suggest that ΔP is lower for passive versus triggered breathing cycles. Vigilance is especially important in the initial stages of mechanical ventilator support, and attention should be paid to triggering efforts when interpreting and comparing machine-determined numerical values for ΔP.

Potentially modifiable respiratory variables contributing to outcome in ICU patients without ARDS: a secondary analysis of PRoVENT.

BACKGROUND: The majority of critically ill patients do not suffer from acute respiratory distress syndrome (ARDS). To improve the treatment of these patients, we aimed to identify potentially modifiable factors associated with outcome of these patients. METHODS: The PRoVENT was an international, multicenter, prospective cohort study of consecutive patients under invasive mechanical ventilatory support. A predefined secondary analysis was to examine factors associated with mortality. The primary endpoint was all-cause in-hospital mortality. RESULTS: 935 Patients were included. In-hospital mortality was 21%. Compared to patients who died, patients who survived had a lower risk of ARDS according to the 'Lung Injury Prediction Score' and received lower maximum airway pressure (Pmax), driving pressure (ΔP), positive end-expiratory pressure, and FiO2 levels. Tidal volume size was similar between the groups. Higher Pmax was a potentially modifiable ventilatory variable associated with in-hospital mortality in multivariable analyses. ΔP was not independently associated with in-hospital mortality, but reliable values for ΔP were available for 343 patients only. Non-modifiable factors associated with in-hospital mortality were older age, presence of immunosuppression, higher non-pulmonary sequential organ failure assessment scores, lower pulse oximetry readings, higher heart rates, and functional dependence. CONCLUSIONS: Higher Pmax was independently associated with higher in-hospital mortality in mechanically ventilated critically ill patients under mechanical ventilatory support for reasons other than ARDS. Trial Registration ClinicalTrials.gov (NCT01868321).

Minimizing atelectasis formation during general anaesthesia-oxygen washout is a non-essential supplement to PEEP.

BACKGROUND: Following preoxygenation and induction of anaesthesia, most patients develop atelectasis. We hypothesized that an immediate restoration to a low oxygen level in the alveoli would prevent atelectasis formation and improve oxygenation during the ensuing anaesthesia. METHODS: We randomly assigned 24 patients to either a control group (n = 12) or an intervention group (n = 12) receiving an oxygen washout procedure directly after intubation. Both groups were, depending on body mass index, ventilated with a positive end-expiratory pressure (PEEP) of 6-8 cmH2O during surgery. The atelectasis area was studied by computed tomography before emergence. Oxygenation levels were evaluated by measuring blood gases and calculating estimated venous admixture (EVA). RESULTS: The atelectasis areas expressed as percentages of the total lung area were 2.0 (1.5-2.7) (median [interquartile range]) and 1.8 (1.4-3.3) in the intervention and control groups, respectively. The difference was non-significant, and also oxygenation was similar between the two groups. Compared to oxygenation before the start of anaesthesia, oxygenation at the end of surgery was improved in the intervention group, mean (SD) EVA from 7.6% (6.6%) to 3.9% (2.9%) (P = .019) and preserved in the control group, mean (SD) EVA from 5.0% (5.3%) to 5.6% (7.1%) (P = .59). CONCLUSION: Although the oxygen washout restored a low pulmonary oxygen level within minutes, it did not further reduce atelectasis size. Both study groups had small atelectasis and good oxygenation. These results suggest that a moderate PEEP alone is sufficient to minimize atelectasis and maintain oxygenation in healthy patients.

Open circuit mouthpiece ventilation: Concise clinical review.

In 2013 new "mouthpiece ventilation" modes are being introduced to commercially available portable ventilators. Despite this, there is little knowledge of how to use noninvasive intermittent positive pressure ventilation (NIV) as opposed to bi-level positive airway pressure (PAP) and both have almost exclusively been reported to have been used via nasal or oro-nasal interfaces rather than via a simple mouthpiece. Non-invasive ventilation is often reported as failing because of airway secretion encumbrance, because of hypercapnia due to inadequate bi-level PAP settings, or poor interface tolerance. The latter can be caused by factors such as excessive pressure on the face from poor fit, excessive oral air leak, anxiety, claustrophobia, and patient-ventilator dys-synchrony. Thus, the interface plays a crucial role in tolerance and effectiveness. Interfaces that cover the nose and/or nose and mouth (oro-nasal) are the most commonly used but are more likely to cause skin breakdown and claustrophobia. Most associated drawbacks can be avoided by using mouthpiece NIV. Open-circuit mouthpiece NIV is being used by large populations in some centers for daytime ventilatory support and complements nocturnal NIV via "mask" interfaces for nocturnal ventilatory support. Mouthpiece NIV is also being used for sleep with the mouthpiece fixed in place by a lip-covering flange. Small 15 and 22mm angled mouthpieces and straw-type mouthpieces are the most commonly used. NIV via mouthpiece is being used as an effective alternative to ventilatory support via tracheostomy tube (TMV) and is associated with a reduced risk of pneumonias and other respiratory complications. Its use facilitates "air-stacking" to improve cough, speech, and pulmonary compliance, all of which better maintain quality of life for patients with neuromuscular diseases (NMDs) than the invasive alternatives. Considering these benefits and the new availability of mouthpiece ventilator modes, wider knowledge of this technique is now warranted. This review highlights the indications, techniques, advantages and disadvantages of mouthpiece NIV.