Modes of mechanical ventilation vary between hospitals and intensive care units within a university healthcare system: a retrospective observational study

This research by Jabaley et al was published in the July 2018 issue of BMC Research Notes.
Objective:  As evidence-based guidance to aid clinicians with mechanical ventilation mode selection is scant, we sought to characterize the epidemiology thereof within a university healthcare system and hypothesized that nonconforming approaches could be readily identified. We conducted an exploratory retrospective observational database study of routinely recorded mechanical ventilation parameters between January 1, 2010 and December 31, 2016 from 12 intensive care units. Mode epoch count proportions were examined using Chi squared and Fisher exact tests as appropriate on an inter-unit basis with outlier detection for two test cases via post hoc pairwise analyses of a binomial regression model.  Results:  Final analysis included 559,734 mode epoch values. Significant heterogeneity was demonstrated between individual units (P < 0.05 for all comparisons). One unit demonstrated heightened utilization of high-frequency oscillatory ventilation, and three units demonstrated frequent synchronized intermittent mandatory ventilation utilization. Assist control ventilation was the most commonly recorded mode (51%), followed by adaptive support ventilation (23.1%). Volume-controlled modes were about twice as common as pressure-controlled modes (64.4% versus 35.6%). Our methodology provides a means by which to characterize the epidemiology of mechanical ventilation approaches and identify nonconforming practices. The observed variability warrants further clinical study about contributors and the impact on relevant outcomes.

The full text of this article in BMC Research Notes is available via this link.


Intensive care doctors’ preferences for arterial oxygen tension levels in mechanically ventilated patients

This article by Schjorring and others was published in Acta Anaesthesioligica Scandinavica in June 2018.
Background:  Oxygen is liberally administered in intensive care units (ICUs). Nevertheless, ICU doctors’ preferences for supplementing oxygen are inadequately described. The aim was to identify ICU doctors’ preferences for arterial oxygenation levels in mechanically ventilated adult ICU patients.
Methods:  In April to August 2016, an online multiple-choice 17-part-questionnaire was distributed to 1080 ICU doctors in seven Northern European countries. Repeated reminder e-mails were sent. The study ended in October 2016.
Results:  The response rate was 63%. When evaluating oxygenation 52% of respondents rated arterial oxygen tension (PaO2 ) the most important parameter; 24% a combination of PaO2 and arterial oxygen saturation (SaO2 ); and 23% preferred SaO2 . Increasing, decreasing or not changing a default fraction of inspired oxygen of 0.50 showed preferences for a PaO2 around 8 kPa in patients with chronic obstructive pulmonary disease, a PaO2 around 10 kPa in patients with healthy lungs, acute respiratory distress syndrome or sepsis, and a PaO2 around 12 kPa in patients with cardiac or cerebral ischaemia. Eighty per cent would accept a PaO2 of 8 kPa or lower and 77% would accept a PaO2 of 12 kPa or higher in a clinical trial of oxygenation targets.
Conclusion:  Intensive care unit doctors preferred PaO2 to SaO2 in monitoring oxygen treatment when peripheral oxygen saturation was not included in the question. The identification of PaO2 as the preferred target and the thorough clarification of preferences are important when ascertaining optimal oxygenation targets. In particular when designing future clinical trials of higher vs lower oxygenation targets in ICU patients.
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Risk Stratification in Pediatric Acute Respiratory Distress Syndrome

This study aims to describe the epidemiology of patients with PARDS across Asia and evaluate whether the Pediatric Acute Lung Injury Consensus Conference risk stratification accurately predicts outcome in PARDS | Critical Care Medicine

Objectives: The Pediatric Acute Lung Injury Consensus Conference developed a pediatric specific definition for acute respiratory distress syndrome (PARDS). In this definition, severity of lung disease is stratified into mild, moderate, and severe groups. We aim to describe the epidemiology of patients with PARDS across Asia and evaluate whether the Pediatric Acute Lung Injury Consensus Conference risk stratification accurately predicts outcome in PARDS.


Measurements and Main Results: Data on epidemiology, ventilation, adjunct therapies, and clinical outcomes were collected. Patients were followed for 100 days post diagnosis of PARDS. A total of 373 patients were included. There were 89 (23.9%), 149 (39.9%), and 135 (36.2%) patients with mild, moderate, and severe PARDS, respectively. The most common risk factor for PARDS was pneumonia/lower respiratory tract infection (309 [82.8%]). Higher category of severity of PARDS was associated with lower ventilator-free days (22 [17-25], 16 [0-23], 6 [0-19]; p < 0.001 for mild, moderate, and severe, respectively) and PICU free days (19 [11-24], 15 [0-22], 5 [0-20]; p < 0.001 for mild, moderate, and severe, respectively). Overall PICU mortality for PARDS was 113 of 373 (30.3%), and 100-day mortality was 126 of 317 (39.7%). After adjusting for site, presence of comorbidities and severity of illness in the multivariate Cox proportional hazard regression model, patients with moderate (hazard ratio, 1.88 [95% CI, 1.03-3.45]; p = 0.039) and severe PARDS (hazard ratio, 3.18 [95% CI, 1.68, 6.02]; p < 0.001) had higher risk of mortality compared with those with mild PARDS.

Conclusions: Mortality from PARDS is high in Asia. The Pediatric Acute Lung Injury Consensus Conference definition of PARDS is a useful tool for risk stratification.

Full reference: Wong, J, J-M. et al. (2017) Risk Stratification in Pediatric Acute Respiratory Distress Syndrome: A Multicenter Observational Study. Critical Care Medicine. Published online: July 26 2017


Identifying barriers to early mobilisation among mechanically ventilated patients

Mechanically ventilated patients can be at risk for functional decline. Early mobilisation of mechanically ventilated patients can improve outcomes after critical illness to prevent this decline | Intensive & Critical Care Nursing


Aim: The aim of this study is to examine whether nurses’ attitudes and beliefs are barriers for early mobilisation and evaluate whether an education intervention can improve early mobilisation.

Results: Dependent Sample T-test revealed a statistically significant increase in post-test responses for the subscales knowledge, attitudes, and behaviours with early mobilisation. This over-all increase in post-test results support that understanding barriers can improve patient outcomes.

Conclusion: Use of structured surveys to identify barriers for early mobilisation among nursing can assist in providing targeted education that address nurse’s perception. The education intervention appeared to have a positive impact on attitudes but it is unknown if the difference was sustained over time or affected participants practice or patient outcomes.

Full reference: Johnson, K. et al. (2017) Identifying barriers to early mobilisation among mechanically ventilated patients in a trauma intensive care unit. Intensive & Critical Care Nursing. Published online: 22 July 2017

A Review Of The Quality Of Care Provided To Patients Receiving Acute Non-Invasive Ventilation

This report focuses on the quality of acute non-invasive ventilation clinical care, for patients aged 16 years or older who are admitted to hospital | National Confidential Enquiry into Patient Outcome and Death 

inspiring change

Whilst this is a report looking at the care provided to patients receiving acute non- invasive ventilation (NIV), it must be noted that the most common condition that NIV is  used for in hospital is chronic obstructive pulmonary disease (COPD). COPD accounts for around 25% of deaths from lung disease, is the fifth biggest killer disease in the UK and with around 115,000 emergency hospital admissions per year is the second most common reason for hospital admission.

Approximately 20% of patients with COPD present to hospital in acidotic ventilatory failure (elevated carbon dioxide, CO2 ). Once CO2 levels have started to rise, a small
further reduction in breathing will lead to a larger rise in CO2 levels and worsening of acidosis. This leads to a downward spiral and eventually, coma and death. Rapid access to treatment as soon as possible after respiratory acidosis develops is therefore important. NIV can provide this support by using a mask or similar device to attach a
ventilator to the patient.

Effect of Intensive vs Moderate Alveolar Recruitment Strategies Added to Lung-Protective Ventilation on Postoperative Pulmonary Complications: A Randomised Clinical Trial

This randomised clinical trial by Costa Leme et al was published in JAMA: Journal of the American Medical Association in April 2017.  The published copy is available in Rotherham Health Care Library.  The full text of the article can be accessed with a Rotherham NHS Athens Password via this link.

Perioperative lung-protective ventilation has been recommended to reduce pulmonary complications after cardiac surgery. The protective role of a small tidal volume (VT) has been established, whereas the added protection afforded by alveolar recruiting strategies remains controversial.

Objective:  To determine whether an intensive alveolar recruitment strategy could reduce postoperative pulmonary complications, when added to a protective ventilation with small VT.

Design, Setting, and Participants:  Randomized clinical trial of patients with hypoxemia after cardiac surgery at a single ICU in Brazil (December 2011-2014).

Interventions:  Intensive recruitment strategy (n=157) or moderate recruitment strategy (n=163) plus protective ventilation with small VT.

Outcomes and Measures:  Severity of postoperative pulmonary complications computed until hospital discharge, analyzed with a common odds ratio (OR) to detect ordinal shift in distribution of pulmonary complication severity score (0-to-5 scale, 0, no complications; 5, death). Prespecified secondary outcomes were length of stay in the ICU and hospital, incidence of barotrauma, and hospital mortality.

Results:  All 320 patients (median age, 62 years; IQR, 56-69 years; 125 women [39%]) completed the trial. The intensive recruitment strategy group had a mean 1.8 (95% CI, 1.7 to 2.0) and a median 1.7 (IQR, 1.0-2.0) pulmonary complications score vs 2.1 (95% CI, 2.0-2.3) and 2.0 (IQR, 1.5-3.0) for the moderate strategy group. Overall, the distribution of primary outcome scores shifted consistently in favor of the intensive strategy, with a common OR for lower scores of 1.86 (95% CI, 1.22 to 2.83; P = .003). The mean hospital stay for the moderate group was 12.4 days vs 10.9 days in the intensive group (absolute difference, -1.5 days; 95% CI, -3.1 to -0.3; P = .04). The mean ICU stay for the moderate group was 4.8 days vs 3.8 days for the intensive group (absolute difference, -1.0 days; 95% CI, -1.6 to -0.2; P = .01). Hospital mortality (2.5% in the intensive group vs 4.9% in the moderate group; absolute difference, -2.4%, 95% CI, -7.1% to 2.2%) and barotrauma incidence (0% in the intensive group vs 0.6% in the moderate group; absolute difference, -0.6%; 95% CI, -1.8% to 0.6%; P = .51) did not differ significantly between groups.

Conclusions and Relevance:  Among patients with hypoxemia after cardiac surgery, the use of an intensive vs a moderate alveolar recruitment strategy resulted in less severe pulmonary complications while in the hospital.

Patients’ experience of thirst while being conscious and mechanically ventilated

Kjeldsen, C.L. et al. Nursing in Critical Care. Published online: 25 January 2017


Background: Because of changes in sedation strategies, more patients in the intensive care unit (ICU) are conscious. Therefore, new and challenging tasks in nursing practice have emerged, which require a focus on the problems that patients experience. Thirst is one such major problem, arising because the mechanical ventilator prevents the patients from drinking when they have the urge to do so. To gain a deeper understanding of the patients’ experiences and to contribute new knowledge in nursing care, this study focuses on the patients’ experiences of thirst during mechanical ventilation (MV) while being conscious.

Conclusion: Patients associate feelings of desperation, anxiety and powerlessness with the experience of thirst. These feelings have a negative impact on their psychological well-being. A strategy in the ICU that includes no sedation for critically ill patients in need of MV introduces new demands on the nurses who must care for patients who are struggling with thirst.

Relevance to clinical practice: This study shows that despite several practical attempts to relieve thirst, it remains a paramount problem for the patients. ICU nurses need to increase their focus on issues of thirst and dry mouth, which are two closely related issues for the patients. Communication may be a way to involve the patients, recognize and draw attention to their problem.

Read the full abstract here