Liberation from invasive mechanical ventilation: a nationwide survey among intensive care units in the Netherlands

Abstract

Background: Liberation from invasive mechanical ventilation is a milestone in critical care, but approaches vary. This survey aimed to describe current ventilator liberation practices, relate them to available evidence, and identify areas for improvement.

Methods: A survey was performed among Dutch intensive care unit (ICU) sites. The survey evaluated practice in seven domains of ventilator liberation: protocol availability, transition from controlled to assisted ventilation, spontaneous breathing trials (SBT), cuff-leak test, postextubation support, weaning failure and tracheostomised weaning.

Results: The survey response rate was 93% (132/142), representing 97% (69/71) of Dutch ICUs. Protocols for postextubation support and weaning failure were available in less than half of the ICUs (44% and 49%, respectively). The transition from controlled to assisted ventilation is regularly evaluated daily in 78% of ICUs. Assisted ventilation tolerance is mainly assessed by clinical signs, respiratory parameters and non-invasive manoeuvres that assess respiratory drive (P_0.1). SBTs are regularly performed in 58% of ICUs, using one or more of the following methods: T-piece (52%), pressure support+positive end expiratory pressure (32%) and continuous positive airway pressure (28%). Cuff-leak tests are seldom performed (1.4%), predominantly in cases of intubation for upper-airway obstruction (92%). Postextubation respiratory support with high-flow nasal oxygen or non-invasive ventilation is used at least as often with therapeutic (43%/13%) rather than preventive (35%/4%) of facilitative intent (29%/3%). Delirium screening (87%) and reconsidering sedation (84%) are frequently assessed in case of weaning failure. Regular use of closed-loop ventilation is reported in a minority of ICUs throughout the process of ventilator liberation (3-9%).

Conclusions: Various aspects of ventilator liberation practices show only limited alignment with existing guidelines. The results of this survey pinpoint areas to prioritise in guideline and practice improvement.

Keywords: Critical Care; Surveys and Questionnaires.

Figure 1. Clinical tools and parameters used to determine the tolerance of assisted ventilation after transition from controlled to assisted ventilation. Clinical signs were specified as transpiration, paradoxical breathing, subcostal retractions and/or agitation. EAdi, electrical activity of the diaphragm; EIT, electrical impedance tomography; Pes, oesophageal pressure measurement; P_occ, occlusion pressure; P_mus: respiratory muscle pressure; P_0.1, occlusion pressure at 100 ms; RSBI, Rapid Shallow Breathing Index; US, ultrasound.

Figure 2. SBT practice. (A) Proportion of centres that perform an SBT in patients on IMV for more than 48 hours; (B): default respiratory support settings during SBT (multiple options possible); (C) the duration regularly used to perform an SBT. The questions in figure 2c could be answered using a Likert scale. For the purpose of clear depiction, Likert scales were collapsed into regular use (a combination of the answer options ‘often’ and ‘always’ or no regular use (a combination of ‘never’, ‘rarely’ and ‘sometimes’). CPAP, continuous positive airway pressure; IMV, invasive mechanical ventilation; PEEP, positive end expiratory pressure; PS, pressure support; SBT, spontaneous breathing trial.

Figure 3. The use of postextubation respiratory support types per ICU patient category. Use of COT, HFNO and NIV as postextubation respiratory support in the general population. COPD, chronic obstructive pulmonary disease; COT, conventional oxygen therapy; HFNO, high-flow nasal oxygen, ICU, intensive care unit; NIV, non-invasive ventilation.

Figure 4. The use of HFNO and NIV as postextubation respiratory support for different indications. Facilitating: to facilitate early extubation. Preventive: start non-invasive respiratory support immediately after extubation to prevent postextubation respiratory failure. Therapeutic: initially start conventional oxygen therapy but switch to non-invasive respiratory support to avoid reintubation in patients with post-extubation respiratory failure. HFNO, high-flow nasal oxygen, NIV, non-invasive ventilation.