Inspiratory and end-expiratory effects of lung recruitment in the prone position on dorsal lung aeration - new physiological insights in a secondary analysis of a randomised controlled study in post-cardiac surgery patients.

Background: Cardiac surgery produces dorso-basal atelectasis and ventilation/perfusion mismatch, associated with infection and prolonged intensive care. A postoperative lung volume recruitment manoeuvre to decrease the degree of atelectasis is routine. In patients with severe respiratory failure, prone positioning and recruitment manoeuvres may increase survival, oxygenation, or both.

Gas distribution by EIT during PEEP inflation: PEEP response and optimal PEEP with lowest trans-pulmonary driving pressure can be determined without esophageal pressure during a rapid PEEP trial in patients with acute respiratory failure.

. Protective ventilation should be based onmechanics and transpulmonary driving pressure (ΔPTP), as this 'hits' the lung directly..

Can we estimate transpulmonary pressure without an esophageal balloon?-yes.

A protective ventilation strategy is based on separation of lung and chest wall mechanics and determination of transpulmonary pressure. So far, this has required esophageal pressure measurement, which is cumbersome, rarely used clinically and associated with lack of consensus on the interpretation of measurements. We have developed an alternative method based on a positive end expiratory pressure (PEEP) step procedure where the PEEP-induced change in end-expiratory lung volume is determined by the ventilator pneumotachograph.

Isocapnic hyperventilation provides early extubation after head and neck surgery: A prospective randomized trial.

Background: Isocapnic hyperventilation (IHV) shortens recovery time after inhalation anaesthesia by increasing ventilation while maintaining a normal airway carbon dioxide (CO)-level. One way of performing IHV is to infuse CO to the inspiratory limb of a breathing circuit during mechanical hyperventilation (HV). In a prospective randomized study, we compared this IHV technique to a standard emergence procedure (control).

Evaluation of lung and chest wall mechanics during anaesthesia using the PEEP-step method.

Background: Postoperative pulmonary complications are common. Between patients there are differences in lung and chest wall mechanics. Individualised mechanical ventilation based on measurement of transpulmonary pressures would be a step forward.

Evaluation of a method for isocapnic hyperventilation: a clinical pilot trial.

Background: Isocapnic hyperventilation (IHV) is a method that shortens time to extubation after inhalation anaesthesia using hyperventilation (HV) without lowering airway CO . In a clinical trial on patients undergoing long-duration sevoflurane anaesthesia for major ear-nose-throat (ENT) surgery, we evaluated the utility of a technique for CO delivery (DCO ) to the inspiratory limb of a closed breathing circuit, during HV, to achieve isocapnia.

Methods: Fifteen adult ASA 1-3 patients were included.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016.

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Transpulmonary and pleural pressure in a respiratory system model with an elastic recoiling lung and an expanding chest wall.

Background: We have shown in acute lung injury patients that lung elastance can be determined by a positive end-expiratory pressure (PEEP) step procedure and proposed that this is explained by the spring-out force of the rib cage off-loading the chest wall from the lung at end-expiration. The aim of this study was to investigate the effect of the expanding chest wall on pleural pressure during PEEP inflation by building a model with an elastic recoiling lung and an expanding chest wall complex.

Methods: Test lungs with a compliance of 19, 38, or 57 ml/cmH2O were placed in a box connected to a plastic container, 3/4 filled with water, connected to a water sack of 10 l, representing the abdomen.

Chest electrical impedance tomography examination, data analysis, terminology, clinical use and recommendations: consensus statement of the TRanslational EIT developmeNt stuDy group.

Electrical impedance tomography (EIT) has undergone 30 years of development. Functional chest examinations with this technology are considered clinically relevant, especially for monitoring regional lung ventilation in mechanically ventilated patients and for regional pulmonary function testing in patients with chronic lung diseases. As EIT becomes an established medical technology, it requires consensus examination, nomenclature, data analysis and interpretation schemes.

Isocapnic hyperventilation shortens washout time for sevoflurane - an experimental in vivo study.

Background: Isocapnic hyperventilation (IHV) is a method that fastens weaning from inhalation anaesthesia by increasing airway concentration of carbon dioxide (CO2 ) during hyperventilation (HV). In an animal model, we evaluated a technique of adding CO2 directly to the breathing circuit of a standard anaesthesia apparatus.

Methods: Eight anaesthetised pigs weighing 28 ± 2 kg were intubated and mechanically ventilated.

A simple method for isocapnic hyperventilation evaluated in a lung model.

Background: Isocapnic hyperventilation (IHV) has the potential to increase the elimination rate of anaesthetic gases and has been shown to shorten time to wake-up and post-operative recovery time after inhalation anaesthesia. In this bench test, we describe a technique to achieve isocapnia during hyperventilation (HV) by adding carbon dioxide (CO2) directly to the breathing circuit of a standard anaesthesia apparatus with standard monitoring equipment.

Methods: Into a mechanical lung model, carbon dioxide was added to simulate a CO2 production (V(CO2)) of 175, 200 and 225 ml/min.

Transpulmonary pressure and lung elastance can be estimated by a PEEP-step manoeuvre.

Background: Transpulmonary pressure is a key factor for protective ventilation. This requires measurements of oesophageal pressure that is rarely used clinically. A simple method may be found, if it could be shown that tidal and positive end-expiratory pressure (PEEP) inflation of the lungs with the same volume increases transpulmonary pressure equally.

Determination of 'recruited volume' following a PEEP step is not a measure of lung recruitability.

Background: It has been proposed that the analysis of positive end-expiratory pressure (PEEP)-induced volume changes can quantify alveolar recruitment. The potential of a lung to be recruited is expected to be high in acute respiratory distress syndrome (ARDS), where collapsed lung tissue is very common. The volume change that is beyond the delta volume because of the patient's compliance has been termed 'recruited volume' (RecV).

The assessment of transpulmonary pressure in mechanically ventilated ARDS patients.

Purpose: The optimal method for estimating transpulmonary pressure (i.e. the fraction of the airway pressure transmitted to the lung) has not yet been established.